Patent Application
20220179313
The present invention relates to a resist composition and a method of forming a resist pattern.
Priority is claimed on Japanese Patent Application No. 2020-204407, filed on Dec. 9, 2020, the content of which is incorporated herein by reference.
In recent years, in the production of semiconductor elements and liquid crystal display elements, advances in lithography techniques have led to a rapid progress in the field of pattern fining. Typically, pattern fining techniques involve shortening the wavelength (increasing the energy) of the light source for exposure.
Resist materials for use with these types of light sources for exposure require lithography characteristics such as a high resolution capable of reproducing a fine-sized pattern, and a high level of sensitivity to these types of light sources for exposure.
As a resist material that satisfies these requirements, a chemically amplified resist composition that contains a base material component that exhibits changed solubility in a developing solution under action of acid, and an acid generator component that generates acid upon exposure has been used in the related art.
In the formation of the resist pattern, the behavior of acid generated from an acid generator component upon exposure is considered as one factor that has a great influence on lithography characteristics.
On the other hand, a chemically amplified resist composition having both an acid generator component and an acid diffusion controlling agent that controls the diffusion of the acid generated from the acid generator component upon exposure has been proposed.
For example, Patent Document 1 discloses a resist composition containing a resin component that exhibits changed solubility in a developing solution under action of acid, an acid generator component, and an amine compound, as an acid diffusion controlling agent.
[Patent Document]
With the further progress of lithography technology and resist pattern fining, for example, it is aimed to form a fine pattern of several tens of nanometers in lithography by EUV and EB. As the resist pattern size becomes smaller as described above, resist materials are required to improve each of the lithography characteristics such as sensitivity, resolution, and roughness reduction property without the trade-off thereof. In addition, it is also required that a resist pattern having high rectangularity can be formed.
The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a resist composition having good sensitivity, good resolution, good roughness reducing property, and good pattern shape, and a method of forming a resist pattern using the resist composition.
In order to achieve the above-described object, the present invention employs the following configurations.
That is, the first aspect of the present invention is a resist composition that generates acid upon exposure and exhibits changed solubility in a developing solution under action of acid, where the resist composition contains a resin component (A1) that exhibits changed solubility in a developing solution under action of acid; and a photodecomposable base (D0) that controls diffusion of acid generated upon exposure, wherein the resin component (A1) has a constitutional unit (a0) represented by General Formula (a0-1), and an acid dissociation constant (pKa) of a conjugate acid of the photodecomposable base (D0) is 4.0 or less.
[In the formula, R01 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 01 represents a single bond or a divalent linking group. 01 represents a hydrocarbon group which may have a substituent. 02 represents a single bond or a divalent linking group, Ra02 represents a hydrogen atom, a hydroxy group, or a hydrocarbon group which may have a substituent. The above Ar represents a benzene ring or a naphthalene ring. 01 and Ra02 may be bonded to each other to form a ring with a secondary carbon atom to which Ra01 and Ya02 are bonded, Ya02, a carbon atom of Ar, to which Ya02 is bonded, and a carbon atom of Ar, to which Ra02 is bonded. n01 represents an integer in a range of 1 to 6 as long as it is allowed by valence.]
The second aspect of the present invention is a method of forming a resist pattern, including a step of forming a resist film on a support using the resist composition according to the first aspect, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern.
According to the present invention, it is possible to provide a resist composition having good sensitivity, good resolution, good roughness reducing property, and good pattern shape, and a method of forming a resist pattern using the resist composition.
In the present specification and the scope of the present claims, the “aliphatic” is a relative concept used with respect to the “aromatic” and defines a group or compound that has no aromaticity.
The “alkyl group” includes linear, branched, and cyclic monovalent saturated hydrocarbon groups, unless otherwise specified. The same applies to the alkyl group in an alkoxy group.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups, unless otherwise specified.
Examples of the “halogen atom” include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The “constitutional unit” indicates a monomer unit that constitutes the formation of a polymeric compound (a resin, a polymer, or a copolymer).
In a case where “may have a substituent” is described, both of a case where a hydrogen atom (—H) is substituted with a monovalent group and a case where a methylene group (—CH2—) is substituted with a divalent group are included.
The “exposure” is used as a general concept that includes irradiation with any form of radiation.
The “base material component” is an organic compound having a film-forming ability. The organic compounds used as the base material component are roughly classified into a non-polymer and a polymer. As the non-polymer, those having a molecular weight of 500 or more and less than 4,000 are usually used. Hereinafter, a “low molecular weight compound” refers to a non-polymer having a molecular weight of 500 or more and less than 4,000. As the polymer, those having a molecular weight of 1,000 or more are usually used. Hereinafter, a “resin”, a “polymeric compound”, or a “polymer” refers to a polymer having a molecular weight of 1,000 or more. As the molecular weight of the polymer, a polystyrene-equivalent weight average molecular weight determined by gel permeation chromatography (GPC) is used.
The “constitutional unit derived from” means a constitutional unit that is formed by the cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond.
In the “acrylic acid ester”, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent (Raαx) that is substituted for the hydrogen atom bonded to the carbon atom at the α-position is an atom other than the hydrogen atom, or a group. Further, an itaconic acid diester in which the substituent (Raαx) is substituted with a substituent having an ester bond or an α-hydroxyacryl ester in which the substituent (Rαx) is substituted with a hydroxyalkyl group or a group obtained by modifying a hydroxyl group of the hydroxyalkyl group can be mentioned as the acrylic acid ester. A carbon atom at the α-position of acrylic acid ester indicates the carbon atom bonded to the carbonyl group of acrylic acid unless otherwise specified.
Hereinafter, the acrylic acid ester obtained by substituting a hydrogen atom bonded to the carbon atom at the α-position with a substituent is also referred to as an α-substituted acrylic acid ester.
The “derivative” includes a compound obtained by substituting a hydrogen atom at the α-position of an object compound with another substituent such as an alkyl group or a halogenated alkyl group; and a derivative thereof. Examples of the derivative thereof include a derivative obtained by substituting the hydrogen atom of a hydroxyl group of an object compound in which a hydrogen atom at the α-position may be substituted with a substituent, with an organic group; and a derivative obtained by bonding a substituent other than the hydroxyl group to an object compound in which a hydrogen atom at the α-position may be substituted with a substituent. The α-position refers to the first carbon atom adjacent to the functional group unless otherwise specified.
Examples of the substituent that is substituted for the hydrogen atom at the α-position of hydroxystyrene include the same one as Rαx.
In the present specification and the scope of the present claims, asymmetric carbon atoms may be present, and thus enantiomers or diastereomers may be present depending on the structures represented by the chemical formula. In that case, these isomers are represented by one chemical formula. These isomers may be used alone or in the form of a mixture.
(Resist Composition)
The resist composition according to the present embodiment is a resist composition that generates acid upon exposure and exhibits changed solubility in a developing solution under action of acid.
Such a resist composition contains a base material component (A) (hereinafter, also referred to as a “component (A)”) that exhibits changed solubility in a developing solution under action of acid, and a photodecomposable base (D0) (hereinafter, also referred to as a “component (D0)”) of which the acid dissociation constant (pKa) of the conjugate acid is 4.0 or less.
In a case where a resist film is formed using the resist composition according to the present embodiment and the formed resist film is subjected to selective exposure, an acid is generated at exposed portions of the resist film, and the generated acid acts on the component (A) to change the solubility of the component (A) in a developing solution, whereas the solubility of the component (A) in a developing solution is not changed at unexposed portions of the resist film, which generates the difference in solubility in the developing solution between exposed portions and unexposed portions of the resist film.
The resist composition according to the present embodiment may be a positive-tone resist composition or a negative-tone resist composition.
Further, in the formation of a resist pattern, the resist composition according to the present embodiment can be applied to an alkali developing process using an alkali developing solution in the developing treatment, or a solvent developing process using an organic developing solution in the developing treatment.
That is, the resist composition according to the present embodiment is a “positive-tone resist composition for an alkali developing process” that forms a positive-tone resist pattern in an alkali developing process and is a “negative-tone resist composition for a solvent developing process” that forms a negative-tone resist pattern in a solvent developing process.
<Component (A)>
In the resist composition according to the present embodiment, the component (A) contains a resin component (A1) (hereinafter, also referred to as a “component (A1)”) that exhibits changed solubility in a developing solution under action of acid. This resin component (A1) has a constitutional unit (a0) represented by General Formula (a0-1).
As the component (A), at least the component (A1) is used, and at least one of another polymeric compound and another low molecular weight compound may be used in combination with the component (A1).
In the resist composition according to the present embodiment, the component (A) may be used alone or in a combination of two or more kinds thereof.
In regard to component (A1)
The component (A1) is a resin component that exhibits changed solubility in a developing solution under action of acid.
The component (A1) has a constitutional unit (a0) represented by General Formula (a0-1).
The component (A1) may have other constitutional units as necessary in addition to the constitutional unit (a0).
<<Constitutional Unit (a0)>>
The constitutional unit (a0) is a constitutional unit represented by General Formula (a0-1).
[In the formula, R01 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Ya01 represents a single bond or a divalent linking group. Ra01 represents a hydrocarbon group which may have a substituent. Ya02 represents a single bond or a divalent linking group, Ra02 represents a hydrogen atom, a hydroxy group, or a hydrocarbon group which may have a substituent. The above Ar represents a benzene ring or a naphthalene ring. Ra01 and Ra02 may be bonded to each other to form a ring with a secondary carbon atom to which Ra01 and Ya02 are bonded, Ya02, a carbon atom of Ar, to which Ya02 is bonded, and a carbon atom of Ar, to which Ra02 is bonded. n01 represents an integer in a range of 1 to 6 as long as it is allowed by valence.]
In General Formula (a0-1), R01 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms as R01 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
R01 is particularly preferably a hydrogen atom or a methyl group in terms of industrial availability.
In General Formula (a0-1), Ya01 represents a single bond or a divalent linking group.
The divalent linking group as Ya01 is not particularly limited, and suitable examples thereof include a divalent hydrocarbon group which may have a substituent, and a divalent linking group having hetero atoms.
Divalent hydrocarbon group which may have substituent:
In a case where Ya01 represents a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
Aliphatic hydrocarbon group as Ya01
The aliphatic hydrocarbon group indicates a hydrocarbon group that has no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated. In general, it is preferable that the aliphatic hydrocarbon group is saturated.
Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure thereof.
Linear or Branched Aliphatic Hydrocarbon Group
The linear aliphatic hydrocarbon group described above preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.
The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [—CH2—], an ethylene group [—(CH2)2—], a trimethylene group [—(CH2)3—], a tetramethylene group [—(CH2)4—], and a pentamethylene group [—(CH2)5—].
The branched aliphatic hydrocarbon group described above preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkylalkylene groups, for example, alkylmethylene groups such as —CH(CH3)—, —CH(CH2CH3)—, —C(CH3)2—, —C(CH3)(CH2CH3)—, —C(CH3)(CH2CH2CH3)—, and —C(CH2CH3)2—; alkylethylene groups such as —CH(CH3)CH2—, —CH(CH3)CH(CH3)—, —C(CH3)2CH2—, —CH(CH2CH3)CH2—, and —C(CH2CH3)2—CH2—; alkyltrimethylene groups such as —CH(CH3)CH2CH2—, and —CH2CH(CH3)CH2—; and alkyltetramethylene groups such as —CH(CH3)CH2CH2CH2—, and —CH2CH(CH3)CH2CH2—. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may have or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, which has been substituted with a fluorine atom, and a carbonyl group.
Aliphatic Hydrocarbon Group Containing Ring in Structure Thereof
Examples of the aliphatic hydrocarbon group containing a ring in the structure thereof include a cyclic aliphatic hydrocarbon group which may have a substituent containing a hetero atom in the ring structure thereof (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group obtained by bonding the cyclic aliphatic hydrocarbon group to the terminal of a linear or branched aliphatic hydrocarbon group, and a group obtained by interposing the cyclic aliphatic hydrocarbon group in a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same ones as those described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably a group having 7 to 12 carbon atoms. Specific examples of the polycyclic alicyclic hydrocarbon group include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The cyclic aliphatic hydrocarbon group may have or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and still more preferably a methoxy group or an ethoxy group.
The halogen atom as the substituent is preferably a fluorine atom.
Examples of the halogenated alkyl group as the substituent include groups obtained by substituting part or all of hydrogen atoms in the above-described alkyl groups with the above-described halogen atoms.
In the cyclic aliphatic hydrocarbon group, part of carbon atoms constituting the ring structure thereof may be substituted with a substituent containing a hetero atom. The substituent containing a hetero atom is preferably —O—, —C(═O)—O—, —S—, —S(═O)2—, or —S(═O)2—O—.
Aromatic hydrocarbon group as Ya01
The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having (4n+2) π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the number of carbon atoms in a substituent is not included in the number of carbon atoms.
Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring obtained by substituting part of carbon atoms constituting the above-described aromatic hydrocarbon ring with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.
Specific examples of the aromatic hydrocarbon group include a group (an arylene group or a heteroarylene group) obtained by removing two hydrogen atoms from the above-described aromatic hydrocarbon ring or the above-described aromatic heterocyclic ring; a group obtained by removing two hydrogen atoms from an aromatic compound having two or more aromatic rings (such as biphenyl or fluorene); and a group (for example, a group obtained by further removing one hydrogen atom from an aryl group in arylalkyl groups such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group) obtained by substituting one hydrogen atom of a group (an aryl group or a heteroaryl group) obtained by removing one hydrogen atom from the above aromatic hydrocarbon ring or the above aromatic heterocyclic ring, with an alkylene group. The alkylene group bonded to the aryl group or the heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.
With respect to the aromatic hydrocarbon group, the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of substituents include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
Examples of the alkoxy group, the halogen atom, and the halogenated alkyl group, as the substituent, include those exemplified as the substituent that is substituted for a hydrogen atom contained in the cyclic aliphatic hydrocarbon group.
Divalent linking group containing hetero atom:
In a case where Ya01 represents a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C(═O)—O—, —O—C(═O)—, —C(═O)—, —O—C(═O)—O—, —C(═O)—NH—, —NH—, —NH—C(═NH)—(H may be substituted with a substituent such as an alkyl group, an acyl group, or the like), —S—, —S(═O)2—, —S(═O)2—O—, and a group represented by General Formula —Y21—O—Y22—, —Y21—O—, —Y21—C(═O)—O—, —C(═O)—O—Y21—, —[Y21—C(═O)—O]m, —Y22—, —Y21—O—C(═O)—Y22— or —Y21—S(═O)2—O—Y22— [in the formulae, Y21 and Y22 each independently represent a divalent hydrocarbon group which may have a substituent, O represents an oxygen atom, and m″ represents an integer in a range of 0 to 3].
In a case where the divalent linking group containing a hetero atom is —C(═O)—NH—, —C(═O)—NH—C(═O)—, —NH—, or —NH—C(═NH)—, H may be substituted with a substituent such as an alkyl group, an acyl group, or the like. The substituent (an alkyl group, an acyl group, or the like) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
In General Formulae —Y21—O—Y22—, —Y21—O—, —Y21—C(═O)—O—, —C(═O)—O—Y21—, —[Y21—C(═O)—O]m, —Y22—, —Y21—O—C(═O)—Y22—, and —Y21—S(═O)2—O—Y22—, Y21, and Y22 each independently represent a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same one as the divalent hydrocarbon group which may have a substituent, mentioned in the explanation of the above-described divalent linking group as Ya01.
Y21 is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group.
Y22 is preferably a linear or branched aliphatic hydrocarbon group and more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkyl methylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by General Formula —[Y21—C(═O)—O]m″—Y22—, m″ represents an integer in a range of 0 to 3, preferably an integer in a range of 0 to 2, more preferably 0 or 1, and particularly preferably 1. In other words, it is particularly preferable that the group represented by General Formula —[Y21—C(═O)—O]m′—Y22— represents a group represented by General Formula —Y21—C(═O)—O—Y22—. Among these, a group represented by Formula —(CH2)a′—C(═O)—O—(CH2)b′— is preferable. In the formula, a′ represents an integer in a range of 1 to 10, preferably an integer in a range of 1 to 8, more preferably an integer in a range of 1 to 5, still more preferably 1 or 2, and most preferably 1. b′ represents an integer in a range of 1 to 10, preferably an integer in a range of 1 to 8, more preferably an integer in a range of 1 to 5, still more preferably 1 or 2, and most preferably 1.
Among the above, Ya01 is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. Among these, Ya01 is preferably a single bond.
In General Formula (a0-1), Ra01 represents a hydrocarbon group which may have a substituent.
The hydrocarbon group as Ra01 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group and may be a cyclic hydrocarbon group or a chain-like hydrocarbon group.
Specific examples of the hydrocarbon group which may have a substituent, as Ra01, include a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, and a chain-like alkenyl group which may have a substituent.
Cyclic group which may have substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group indicates a hydrocarbon group that has no aromaticity. In addition, the aliphatic hydrocarbon group may be saturated or may be unsaturated.
The aromatic hydrocarbon group as Ra01 represents a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 4 to 30 carbon atoms, more preferably 5 to 30, still more preferably 5 to 20, and particularly preferably 6 to 15. Here, the number of carbon atoms in a substituent is not included in the number of carbon atoms.
Specific examples of the aromatic ring contained in the aromatic hydrocarbon group as Ra01 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and an aromatic heterocyclic ring obtained by substituting part of carbon atoms constituting one of these aromatic rings with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specific examples of the aromatic hydrocarbon group as Ra01 include a group (an aryl group such as a phenyl group or a naphthyl group) obtained by removing one hydrogen atom from the above-described aromatic ring and a group (an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, 1-naphthylethyl group, or a 2-naphthylethyl group) obtained by substituting one hydrogen atom in the aromatic ring with an alkylene group. The alkylene group (an alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.
Examples of the cyclic aliphatic hydrocarbon group as Ra01 include aliphatic hydrocarbon groups containing a ring in the structure thereof.
Examples of the aliphatic hydrocarbon group containing a ring in the structure thereof include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group obtained by bonding the alicyclic hydrocarbon group to the terminal of a linear or branched aliphatic hydrocarbon group, and a group obtained by interposing the alicyclic hydrocarbon group is in a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among the above, a polycycloalkane having a bridged ring-based polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or a polycycloalkane having a condensed ring-based polycyclic skeleton, such as a cyclic group having a steroid skeleton is preferable.
The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 4 carbon atoms. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [—CH2—], an ethylene group [—(CH2)2—], a trimethylene group [—(CH2)3—], a tetramethylene group [—(CH2)4—], and a pentamethylene group [—(CH2)5—]. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkylalkylene groups, for example, alkylmethylene groups such as —CH(CH3)—, —CH(CH2CH3)—, —C(CH3)2—, —C(CH3)(CH2CH3)—, —C(CH3)(CH2CH2CH3)—, and —C(CH2CH3)2—; alkylethylene groups such as —CH(CH3)CH2—, —CH(CH3)CH(CH3)—, —C(CH3)2CH2—, —CH(CH2CH3)CH2—, and —C(CH2CH3)2—CH2—; alkyltrimethylene groups such as —CH(CH3)CH2CH2—, and —CH2CH(CH3)CH2—; and alkyltetramethylene groups such as —CH(CH3)CH2CH2CH2—, and —CH2CH(CH3)CH2CH2—. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The cyclic hydrocarbon group as Ra01 may contain a hetero atom such as a heterocyclic ring. Specific examples thereof include lactone-containing cyclic groups each represented by General Formulae (a2-r-1) to (a2-r-7) described later, —SO2— containing cyclic groups each represented by General Formulae (a5-r-1) to (a5-r-4) described later, and other heterocyclic groups each represented by Chemical Formulae (r-hr-1) to (r-hr-16) described later.
Chain-like alkyl group which may have substituent:
The chain-like alkyl group as Ra01 may be linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decanyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecil group, an icosyl group, a henicosyl group, and a docosyl group.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15, and most preferably 3 to 10. Specific examples thereof include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.
Chain-like alkenyl group which may have substituent:
A chain-like alkenyl group as Ra01 may be linear or branched, and the chain-like alkenyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (an allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.
Among the above, the chain-like alkenyl group is preferably a linear alkenyl group, more preferably a vinyl group or a propenyl group, and particularly preferably a vinyl group.
In General Formula (a0-1), the substituent in the hydrocarbon group which may have a substituent, as Ra01, may be a monovalent substituent or may be a divalent substituent.
Examples of the monovalent substituent include a carboxy group, a hydroxy group, an amino group, a sulfo group, a halogen atom, a halogenated alkyl group, an alkoxy group, an alkyloxycarbonyl group, and a nitro group.
Examples of the divalent substituent include —O—, —C(═O)—O—, —C(═O)—, —O—C(═O)—O—, —C(═O)—NH—, —NH—, ═N—, —NH—C(═NH)—, —S—, —S(═O)2—, and —S(═O)2—O—. In addition, H in the divalent substituent may be substituted with a substituent such as an alkyl group or an acyl group.
In General Formula (a0-1), Ya02 represents a single bond or a divalent linking group.
The divalent linking group as Ya02 is the same as the divalent linking group as Ya01 described above. Ya02 is preferably a single bond or a linear or branched aliphatic hydrocarbon group, more preferably a single bond or a linear aliphatic hydrocarbon group, still more preferably a single bond, or a methylene group [—CH2—] or an ethylene group [—(CH2)2—], particularly preferably a single bond or a methylene group [—CH2—], and most preferably a single bond.
In General Formula (a0-1), Ra02 represents a hydrogen atom, a hydroxy group, or a hydrocarbon group which may have a substituent.
The hydrocarbon group which may have a substituent, as Ra02, is the same as the hydrocarbon group which may have a substituent, as Ra01 described above.
In General Formula (a0-1), Ar represents a benzene ring or a naphthalene ring, and it is preferably a benzene ring.
In General Formula (a0-1), Ra01 and Ra02 may be bonded to each other to form a ring (hereinafter, may be referred to as a “ring X”) with a secondary carbon atom to which Ra01 and Ya02 are bonded, Ya02, a carbon atom of Ar, to which Ya02 is bonded, and a carbon atom of Ar, to which Ra02 is bonded. In such a case, the ring X and Ar form a condensed ring.
Examples of the ring X include an alicyclic hydrocarbon ring which may have a substituent. The alicyclic hydrocarbon ring is preferably an alicyclic hydrocarbon ring having 4 to 20 carbon atoms, more preferably an alicyclic hydrocarbon ring having 5 to 15 carbon atoms, and still more preferably an alicyclic hydrocarbon ring having 5 to 10 carbon atoms.
Examples of the alicyclic hydrocarbon ring as ring X include aliphatic rings such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, and cyclododecane; and spiroalkanes such as spiro[4.5]decane and spiro[5.5]undecane.
Examples of the substituent which may be contained in the alicyclic hydrocarbon ring include an alkyl group having 1 to 5 carbon atoms, a halogen atom, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxy group.
In General Formula (a0-1), it is preferable that Ra01 is a chain-like hydrocarbon group and Ra02 is a hydrogen atom, or Ra01 and Ra02 are bonded to each other to form the ring X, it is more preferable that Ra01 and Ra02 are bonded to each other to form the ring X.
In General Formula (a0-1), n01 represents an integer in a range of 1 to 6, preferably an integer in a range of 1 to 4, more preferably an integer in a range of 1 or 3, still more preferably 1 or 2, and particularly preferably 1, as long as it is allowed by the valence.
The constitutional unit (a0) is preferably at least one selected from the group consisting of a constitutional unit (a0-1-1) represented by General Formula (a0-1-1) and a constitutional unit (a0-1-2) represented by General Formula (a0-1-2), and more preferably a constitutional unit (a0-1-2).
[In the formulae, R011 and R021 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Ya011 and Ya021 represent a single bond or a divalent linking group. Ra011 represents a linear or branched aliphatic hydrocarbon group. Ya012 represents a single bond or a divalent linking group, Ra012 represents a hydrogen atom or a hydroxy group. Xa represents a secondary carbon atom. X represents an alicyclic hydrocarbon ring which may have a substituent. The Ar represents a benzene ring or a naphthalene ring. n011 and n021 are each independently an integer in a range of 1 to 4.]
In General Formula (a0-1-1), R011 is the same as R01 in General Formula (a0-1).
In General Formula (a0-1-1), Ya011 is the same as Ya01 in General Formula (a0-1).
In General Formula (a0-1-1), Ya012 is the same as Ya02 in General Formula (a0-1). Among the above, Ya012 is preferably a single bond or a linear or branched aliphatic hydrocarbon group, more preferably a single bond or a linear aliphatic hydrocarbon group, still more preferably a single bond, or a methylene group [—CH2—] or an ethylene group [—(CH2)2—], particularly preferably a single bond or a methylene group [—CH2—], and most preferably a single bond.
In General Formula (a0-1-1), the linear or branched aliphatic hydrocarbon group as Ra01 is the same as the linear or branched aliphatic hydrocarbon group as Ra01 in General Formula (a0-1). Among the above, Ra011 is preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 20 carbon atoms, preferably a methyl group, an ethyl group, a propyl group, a 1-methylethyl group, a 1-methylpropyl group, or 2-methylpropyl group, and still more preferably a methyl group.
In General Formula (a0-1-1), Ra012 is preferably a hydrogen atom.
In General Formula (a0-1-1), Ar is the same as Ar in General Formula (a0-1) and is preferably a benzene ring.
In General Formula (a0-1-1), n011 is the same as n01 in General Formula (a0-1), preferably 1 or 2, and more preferably 1.
In General Formula (a0-1-2), R021 is the same as R01 in General Formula (a0-1).
In General Formula (a0-1-2), Ya021 is the same as Ya01 in General Formula (a0-1).
In General Formula (a0-1-2), the alicyclic hydrocarbon ring which may have a substituent, as the ring X, is the same as the alicyclic hydrocarbon ring which may have a substituent, as the ring X in General Formula (a0-1), and it is preferably cyclopentane, cyclohexane, or cycloheptane and more preferably cyclopentane or cyclohexane.
In General Formula (a0-1-2), Ar is the same as Ar in General Formula (a0-1) and is preferably a benzene ring.
In General Formula (a0-1-2), n021 is the same as n01 in General Formula (a0-1), preferably 1 or 2, and more preferably 1.
Specific examples of the constitutional unit (a0) are shown below. In the formulae below, R01 is the same as R01 in General Formula (a0-1).
Among the above, the constitutional unit (a0) is preferably at least one selected from the group consisting of constitutional units each represented by General Formulae (a0-u-1), (a0-u-3), (a0-u-9), (a0-u-13), and (a0-u-15).
The constitutional unit (a0) contained in the component (A1) may be one kind or may be two or more kinds.
The proportion of the constitutional unit (a0) in the component (A1) is preferably 20% by mole or more, more preferably 25% by mole or more, and still more preferably 30% by mole or more, and may be 100% by mole (a homopolymer), with respect to the total (100% by mole) of all constitutional units constituting the component (A1).
In a case where the proportion of the constitutional unit (a0) is set to be equal to or larger than the lower limit value of the preferred range described above, lithography characteristics such as sensitivity and roughness amelioration are improved.
In a case where the component (A1) contains a copolymer having the constitutional unit (a0), the proportion of the constitutional unit (a0) in this copolymer is preferably in a range of 25% to 70% by mole, more preferably in a range of 30% to 65% by mole, and still more preferably in a range of 40% to 60% by mole, with respect to the total (100% by mole) of all constitutional units constituting this copolymer.
In a case where the proportion of the constitutional unit (a0) is set to be equal to or larger than the lower limit value of the preferred range described above, lithography characteristics such as sensitivity and roughness amelioration are improved. On the other hand, in a case where it is equal to or smaller than the upper limit value of the above preferred range, balance with other constitutional units can be obtained, and various lithography characteristics are improved.
<<Other Constitutional Units>>
The component (A1) may have other constitutional units as necessary in addition to the constitutional unit (a0) described above.
Examples of the other constitutional units include a constitutional unit (a1) containing an acid decomposable group having a polarity that is increased under action of acid; a constitutional unit (a10) represented by General Formula (a10-1) described later; a constitutional unit (a2) containing a lactone-containing cyclic group, a —SO2-containing cyclic group, or a carbonate-containing cyclic group; a constitutional unit (a3) containing a polar group-containing aliphatic hydrocarbon group; a constitutional unit (a4) containing an acid non-dissociable aliphatic cyclic group; a constitutional unit derived from styrene; and a constitutional unit derived from a styrene derivative.
In regard to constitutional unit (a1)
The constitutional unit (a1) is a constitutional unit (provided that a constitutional unit corresponding to the constitutional unit (a0) is excluded) containing an acid decomposable group having a polarity that is increased under action of acid.
The “acid decomposable group” indicates a group in which at least part of bonds in the structure of the acid decomposable group can be cleaved under action of acid.
Examples of the acid decomposable group having a polarity that is increased under action of acid include groups which decompose under action of acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (—SO3H). Among these, a polar group containing —OH in the structure thereof (hereinafter, also referred to as an “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is more preferable, and a carboxy group is particularly preferable.
More specific examples of the acid decomposable group include a group (for example, a group obtained by protecting a hydrogen atom of the OH-containing polar group with an acid dissociable group) obtained by protecting the above-described polar group with an acid dissociable group.
Here, the “acid dissociable group” indicates any one of (i) a group in which a bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved under action of acid; and (ii) a group in which part of bonds are cleaved under action of acid, and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid dissociable group and the atom adjacent to the acid dissociable group.
It is necessary that the acid dissociable group that constitutes the acid decomposable group is a group that exhibits a lower polarity than the polar group generated by the dissociation of the acid dissociable group. Thus, in a case where the acid dissociable group is dissociated under action of acid, a polar group that exhibits a higher polarity than the acid dissociable group is generated, whereby the polarity increases. As a result of the above, the polarity of the entire component (A1) is increased. By the increase in the polarity, the solubility in a developing solution relatively changes. The solubility in a developing solution is increased in a case where the developing solution is an alkali developing solution, whereas the solubility in a developing solution is decreased in a case where the developing solution is an organic developing solution.
Examples of the acid dissociable group are the same as those which have been proposed so far as acid dissociable groups for the base resin for a chemically amplified resist composition.
Specific examples of acid dissociable groups of the base resin proposed for a chemically amplified resist composition contains an “acetal-type acid dissociable group”, a “tertiary alkyl ester-type acid dissociable group”, and a “tertiary alkyloxycarbonyl acid dissociable group” described below.
Acetal-type acid dissociable group:
Examples of the acid dissociable group for protecting a carboxy group or a hydroxyl group as a polar group include the acid dissociable group represented by General Formula (a1-r-1) shown below (hereinafter, also referred to as an “acetal-type acid dissociable group”).
[In the formula, Ra′1 and Ra′2 represent a hydrogen atom or an alkyl group. Ra′3 represents a hydrocarbon group, and Ra′3 may be bonded to any one of Ra′1 or Ra′2 to form a ring.]
In General Formula (a1-r-1), it is preferable that at least one of Ra′1 and Ra′2 represents a hydrogen atom and more preferable that both Ra′1 and Ra′2 represent a hydrogen atom.
In a case where Ra′1 or Ra′2 represents an alkyl group, the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. Specific examples thereof preferably include a linear or branched alkyl group. More specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
In General Formula (a1-r-1), examples of the hydrocarbon group as Ra′3 include a linear or branched alkyl group and a cyclic hydrocarbon group.
The linear alkyl group has preferably 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group has preferably 3 to 10 carbon atoms and more preferably 3 to 5 carbon atoms. Specific examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and an isopropyl group is preferable.
In a case where Ra′3 represents a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group and may be a polycyclic group or a monocyclic group.
The aliphatic hydrocarbon group which is a monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane is preferably a monocycloalkane having 3 to 12 carbon atoms, more preferably a monocycloalkane having 3 to 8 carbon atoms, and still more preferably a monocycloalkane having 5 to 6 carbon atoms. Specific examples of the monocycloalkane include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
In a case where the cyclic hydrocarbon group as Ra′3 is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having (4n+2) π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.
Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring obtained by substituting part of carbon atoms constituting the above-described aromatic hydrocarbon ring with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.
Specific examples of the aromatic hydrocarbon group as Ra′3 include a group obtained by removing one hydrogen atom from the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring (an aryl group or a heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound having two or more aromatic rings (biphenyl, fluorene or the like); and a group obtained by substituting one hydrogen atom of the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring with an alkylene group (an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably in a range of 1 to 4, more preferably 1 or 2, and particularly preferably 1.
The cyclic hydrocarbon group as Ra′3 may have a substituent. Examples of the substituent include, —RP1, —RP2—O—RP1, —RP2—CO—RP1, —RP2—CO—ORP1, —RP2—O—CO—RP1, —RP2—OH, —RP2—CN, and —RP2—COOH (hereinafter, these substituents are also collectively referred to as “Ra05”).
Here, RP1 represents a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. In addition, RP2 represents a single bond, a divalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, part or all of hydrogen atoms contained in the chain-like saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group, and the aromatic hydrocarbon group of RP1 and RP2 may be substituted with a fluorine atom. In the aliphatic cyclic hydrocarbon group, one or more of the above-described substituents may be included as a single kind, or one or more of the above-described substituents may be included as a plurality of kinds.
Examples of the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group.
Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo [3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7] dodecanyl group, and an adamantyl group.
Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.
In a case where Ra′3 is bonded to any one of Ra′1 or Ra′2 to form a ring, the cyclic group is preferably a 4-membered to 7-membered ring, and more preferably a 4-membered to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.
Tertiary alkyl ester-type acid dissociable group:
Among the above polar groups, examples of the acid dissociable group for protecting the carboxy group include the acid dissociable group represented by General Formula (a1-r-2) shown below.
Among the acid dissociable groups represented by General Formula (a1-r-2), for convenience, a group which is constituted of alkyl groups is referred to as a “tertiary alkyl ester-type acid dissociable group”.
[In the formula, Ra′4 to Ra′6 each represent a hydrocarbon group, and Ra′5 and Ra′6 may be bonded to each other to form a ring.]
Examples of the hydrocarbon group as Ra′4 include a linear or branched alkyl group, a chain-like or cyclic alkenyl group, and a cyclic hydrocarbon group.
Examples of the linear or branched alkyl group and the cyclic hydrocarbon group (the aliphatic hydrocarbon group which is a monocyclic group, the aliphatic hydrocarbon group which is a polycyclic group, or the aromatic hydrocarbon group) as Ra′4 include the same one as Ra′3 described above.
The chain-like or cyclic alkenyl group as Ra′4 is preferably an alkenyl group having 2 to 10 carbon atoms.
Examples of the hydrocarbon group as Ra′5 and Ra′6 includes the same ones as those mentioned above as Ra′3.
In a case where Ra′5 to Ra′6 are bonded to each other to form a ring, groups represented by General Formula (a1-r2-1), General Formula (a1-r2-2), and General Formula (a1-r2-3) can be suitably mentioned.
On the other hand, in a case where Ra′4 to Ra′6 are not bonded to each other and represent an independent hydrocarbon group, suitable examples thereof include a group represented by General Formula (a1-r2-4).
[In General Formula (a1-r2-1), Ra′10 represents an alkyl group having 1 to 10 carbon atoms or a group represented by General Formula (a1-r2-r1). Ra′11 represents a group that forms an aliphatic cyclic group together with a carbon atom to which Ra′10 is bonded. In General Formula (a1-r2-2), Ya represents a carbon atom. Xa represents a group that forms a cyclic hydrocarbon group together with Ya. Part or all of hydrogen atoms contained in the cyclic hydrocarbon group may be substituted. Ra01 to Ra03 each independently represent a hydrogen atom, a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Part or all of hydrogen atoms contained in the chain-like saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra01 to Ra03 may be bonded with each other to form a cyclic structure. In General Formula (a1-r2-3), Yaa represents a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra04 represents an aromatic hydrocarbon group which may have a substituent. In General Formula (a1-r2-4), Ra′12 and Ra′13 each independently represent a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Part or all of hydrogen atoms contained in the chain-like saturated hydrocarbon group may be substituted. Ra′14 represents a hydrocarbon group which may have a substituent. * represents a bonding site].
In the formula, Ya0 represents a quaternary carbon atom. [Ra031, Ra032, and Ra033 each independently represent a hydrocarbon group which may have a substituent. Here, one or more of Ra031, Ra032, and Ra033 are hydrocarbon groups having at least one polar group.]
In General Formula (a1-r2-1) described above, as the alkyl group having 1 to 10 carbon atoms as Ra′10 the groups mentioned as the linear or branched alkyl group as Ra′3 in General Formula (a1-r-1) are preferable. Ra′10 is preferably an alkyl group having 1 to 5 carbon atoms.
In General Formula (a1-r2-r1), Ya0 represents a quaternary carbon atom. That is, there are four adjacent carbon atoms bonded to Ya0 (carbon atom).
[In General Formula (a1-r2-r1), Ra031, Ra032, and Ra033 each independently represent a hydrocarbon group which may have a substituent. The hydrocarbon groups as Ra031, Ra032, and Ra033 each independently include a linear or branched alkyl group, a chain-like or cyclic alkenyl group, and a cyclic hydrocarbon group.
The linear alkyl groups as Ra031, Ra032, and Ra033 have preferably 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl groups as Ra031, Ra032, and Ra033 have preferably 3 to 10 carbon atoms and more preferably 3 to 5 carbon atoms. Specific examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and an isopropyl group is preferable.
The chain-like or cyclic alkenyl groups as Ra031, Ra032, and Ra033 are preferably an alkenyl group having 2 to 10 carbon atoms.
The cyclic hydrocarbon group as Ra031, Ra032, and Ra033 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group and may be a polycyclic group or a monocyclic group.
The aliphatic hydrocarbon group which is a monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane is preferably a monocycloalkane having 3 to 12 carbon atoms, more preferably a monocycloalkane having 3 to 8 carbon atoms, and still more preferably a monocycloalkane having 5 to 6 carbon atoms. Specific examples of the monocycloalkane include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The aromatic hydrocarbon groups as Ra031, Ra032, and Ra033 are a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having (4n+2) π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring obtained by substituting part of carbon atoms constituting the above-described aromatic hydrocarbon ring with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group obtained by removing one hydrogen atom from the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring (an aryl group or a heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound having two or more aromatic rings (biphenyl, fluorene or the like); and a group obtained by substituting one hydrogen atom of the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring with an alkylene group (an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.
In a case where the hydrocarbon groups represented by Ra031, Ra032, and Ra033 are substituted, examples of the substituent include a hydroxy group, a carboxy group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and the like), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and the like), an alkyloxycarbonyl group.
Among the above examples, as Ra031, Ra032, and Ra033, the hydrocarbon group which may have a substituent is preferably a linear or branched alkyl group which may have a substituent and more preferably a linear alkyl group.
Here, one or more of Ra031, Ra032, and Ra033 are hydrocarbon groups having at least a polar group.]
The “hydrocarbon group having a polar group” includes any one of a hydrocarbon group in which a methylene group (—CH2—) constituting the hydrocarbon group is substituted with a polar group and a hydrocarbon group in which at least one hydrogen atom constituting the hydrocarbon group is substituted with a polar group.
As such a “hydrocarbon group having a polar group”, a functional group represented by General Formula (a1-p1) is preferable.
[In the formula. Ra07 represents a divalent hydrocarbon group having 1 to 12 carbon atoms. Ra08 represents a divalent linking group including a hetero atom. Ra06 represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. np0 represents an integer in a range of 1 to 6.]
In General Formula (a1-p1), Ra07 represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
Ra07 has 1 to 12 carbon atoms, has preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 or 2 carbon atoms.
The hydrocarbon group as Ra07 is preferably a chain-like or cyclic aliphatic hydrocarbon group and more preferably a chain-like hydrocarbon group.
Examples of Ra07 include: linear alkanediyl groups such an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, and a dodecane-1,12-diyl group; branched alkanediyl groups such as a propane-1,2-diyl group, a 1-methylbutane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group; cycloalkanediyl groups such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, a cyclooctane-1,5-diyl group; and polycyclic divalent alicyclic hydrocarbon groups such as a norbornane-1,4-diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, and an adamantane-2,6-diyl group.
Among them, an alkanediyl group is preferable, and a linear alkanediyl group is more preferable.
In General Formula (a1-p1), Ra08 represents a divalent linking group including a hetero atom.
Examples of Ra08 include —O—, —C(═O)—O—, —C(═O)—, —O—C(═O)—O—, —C(═O)—NH—, —NH—, —NH—C(═NH)—(H may be substituted with a substituent such as an alkyl group and an acyl group), —S—, —S(═O)2—, and —S(═O)2—O—.
Among these, —O—, —C(═O)—O—, —C(═O)—, or —O—C(═O)—O— is preferable, and —O— or —C(═O)— is particularly preferable.
In General Formula (a1-p1), Ra06 represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms.
Ra06 has 1 to 12 carbon atoms and has preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, still more preferably 1 to 3 carbon atoms, particularly preferably 1 or 2 carbon atoms, and most preferably 1 carbon atom, from the viewpoint of the solubility in a developing solution.
Examples of the hydrocarbon group as Ra06 include a chain-like hydrocarbon group or a cyclic hydrocarbon group, or a hydrocarbon group obtained by combining a chain-like hydrocarbon group or a cyclic hydrocarbon group.
Examples of the chain-like hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, a 2-ethylhexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, and an n-dodecyl group.
The cyclic hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group.
Examples of the alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1-(adamantan-1-yl)alkane-1-yl group, a norbornyl group, a methylnorbornyl group, and an isobornyl group.
Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.
From the viewpoint of solubility in a developing solution, Ra06 is preferably a chain-like hydrocarbon group, more preferably a chain-like alkyl group, and still more preferably a linear alkyl group.
In General Formula (a1-p1) np0 represents an integer in a range of 1 to 6, is preferably an integer in a range of 1 to 3, more preferably 1 or 2, and still more preferably 1.
Specific examples of the hydrocarbon group having at least a polar group are described below.
In the following formulae, * is a bonding site that is bonded to the quaternary carbon atom (Ya0).
In General Formula (a1-r2-r1), the number of hydrocarbon groups having at least a polar group among Ra031, Ra032, and Ra033 is one or more. The number of hydrocarbon groups may be appropriately determined in consideration of the solubility in a developing solution at the time of forming a resist pattern, for example, one or two are preferable, and one is particularly preferable among Ra031, Ra032, and Ra033.
The above-described hydrocarbon group having at least a polar group may have a substituent other than the polar group. Examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or the like) and a halogenated alkyl group having 1 to 5 carbon atoms.
In General Formula (a1-r2-1), Ra′11 (an aliphatic cyclic group that is formed together with the carbon atom to which Ra′10 is bonded) is preferably the group mentioned as the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group as Ra′3 in General Formula (a1-r-1).
In General Formula (a1-r2-2), examples of the cyclic hydrocarbon group formed by Xa together with Ya include a group in which one or more hydrogen atoms are further removed from a cyclic monovalent hydrocarbon group (an aliphatic hydrocarbon group) as Ra′3 in General Formula (a1-r-1).
The cyclic hydrocarbon group that is formed by Xa together with Ya may have a substituent. Examples of this substituent include the same one as the substituent which may be contained in the cyclic hydrocarbon group as Ra′3.
In General Formula (a1-r2-2), as Ra01 to Ra03, examples of the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group.
Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, as Ra01 to Ra03, include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7] dodecanyl group, and an adamantyl group.
Among them, Ra01 to Ra03 are preferably a hydrogen atom or a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, from the viewpoint of the easy synthesis of a monomer compound from which the constitutional unit (a1) is derived, among them, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.
Examples of the substituent contained in the chain-like saturated hydrocarbon group represented by Ra01 to Ra03 or the aliphatic cyclic saturated hydrocarbon group include the same group as Ra05 described above.
Examples of the group containing a carbon-carbon double bond generated by forming a cyclic structure, which is obtained by bonding two or more of Ra01 to Ra03 to each other, include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylideneethenyl group, and a cyclohexylideneethenyl group. Among these, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylideneethenyl group are preferable from the viewpoint of easy synthesis of a monomer compound from which the constitutional unit (a1) is derived.
In General Formula (a1-r2-3), an aliphatic cyclic group that is formed by Xaa together with Yaa is preferably the group mentioned as the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group as Ra′3 in General Formula (a1-r-1).
In General Formula (a1-r2-3), Examples of the aromatic hydrocarbon group as Ra04 include a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra04 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene or naphthalene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.
Examples of the substituent which may be contained in Ra04 in General Formula (a1-r2-3) include a methyl group, an ethyl group, propyl group, a hydroxy group, a carboxy group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and the like), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and the like), and an alkyloxycarbonyl group.
In General Formula (a1-r2-4), Ra′12 and Ra′13 each independently represent a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Examples of the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms as Ra′12 and Ra′13 include the same one as the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms as Ra01 to Ra03 as described above. Part or all of hydrogen atoms contained in the chain-like saturated hydrocarbon group may be substituted.
Among the above, Ra′12 and Ra′13 are preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, still more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.
In a case where the chain-like saturated hydrocarbon groups represented by Ra′12 and Ra′13 are substituted, examples of the substituent include the same group as Ra05 described above.
In General Formula (a1-r2-4), Ra′14 represents a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group as Ra′14 include a linear or branched alkyl group and a cyclic hydrocarbon group.
The linear alkyl group as Ra′14 has preferably 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group as Ra′14 preferably has 3 to 10 carbon atoms and more preferably 3 to 5 carbon atoms. Specific examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and an isopropyl group is preferable.
In a case where Ra′14 represents a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group and may be a polycyclic group or a monocyclic group.
The aliphatic hydrocarbon group which is a monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane is preferably a monocycloalkane having 3 to 12 carbon atoms, more preferably a monocycloalkane having 3 to 8 carbon atoms, and still more preferably a monocycloalkane having 5 to 6 carbon atoms. Specific examples of the monocycloalkane include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
Examples of the aromatic hydrocarbon group as Ra′14 include the same one as the aromatic hydrocarbon group as Ra04. Among them, Ra′14 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene.
Examples of the substituent which may be contained in Ra′14 include the same one as the substituent which may be contained in Ra04.
In a case where Ra′14 in General Formula (a1-r2-4) is a naphthyl group, the position at which the tertiary carbon atom in General Formula (a1-r2-4) is bonded may be any of the 1-position and the 2-position of the naphthyl group.
In a case where Ra′14 in General Formula (a1-r2-4) is an anthryl group, the position at which the tertiary carbon atom in General Formula (a1-r2-4) is bonded may be any of the 1-position, the 2-position, and 9-position of the anthryl group.
Specific examples of the group represented by General Formula (a1-r2-1) are shown below.
Specific examples of the group represented by General Formula (a1-r2-2) are shown below.
Specific examples of the group represented by General Formula (a1-r2-3) are shown below.
Specific examples of the group represented by General Formula (a1-r2-4) are shown below.
Tertiary alkyloxycarbonyl acid dissociable group:
Among the polar groups, examples of the acid dissociable group for protecting a hydroxyl group include an acid dissociable group (hereinafter, for convenience, also referred to as a “tertiary alkyloxycarbonyl acid dissociable group”) represented by General Formula (a1-r-3) shown below.
[In the formula, Ra′7 to Ra′9 each represent an alkyl group.]
In General Formula (a1-r-3), Ra′7 to Ra′9 are each preferably an alkyl group having 1 to 5 carbon atoms and more preferably an alkyl group having 1 to 3 carbon atoms.
Further, the total number of carbon atoms in each of the alkyl groups is preferably in a range of 3 to 7, more preferably in a range of 3 to 5, and most preferably 3 or 4.
Examples of the constitutional unit (a1) include a constitutional unit derived from acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent; a constitutional unit derived from acrylamide; a constitutional unit in which at least part of hydrogen atoms in a hydroxyl group of a constitutional unit derived from hydroxystyrene or a hydroxystyrene derivative are protected by a substituent including an acid decomposable group; and a constitutional unit in which at least part of hydrogen atoms in —C(═O)—OH of a constitutional unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative are protected by the substituent including an acid decomposable group.
Among the above, the constitutional unit (a1) is preferably a constitutional unit derived from acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent.
Preferred specific examples of such a constitutional unit (a1) include constitutional units represented by General Formula (a1-1) or (a1-2).
[In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va1 represents a divalent hydrocarbon group which may have an ether bond. na1 represents an integer in a range of 0 to 2. Ra1 is an acid dissociable group represented by General Formula (a1-r-1) or (a1-r-2). Wa1 represents an (na2+1)-valent hydrocarbon group, na2 represents an integer in a range of 1 to 3, and Ra2 represents an acid dissociable group represented by General Formula (a1-r-1) or (a1-r-3).]
In General Formula (a1-1), the alkyl group having 1 to 5 carbon atoms as R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group obtained by substituting part or all of hydrogen atoms in the alkyl group having 1 to 5 carbon atoms with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and, an iodine atom, and a fluorine atom is particularly preferable.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group in terms of industrial availability.
In General Formula (a1-1), the divalent hydrocarbon group as Va1 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
The aliphatic hydrocarbon group as the divalent hydrocarbon group represented by Va1 may be saturated or unsaturated. In general, it is preferable that the aliphatic hydrocarbon group is saturated.
Specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure thereof.
The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.
The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [—CH2—], an ethylene group [—(CH2)2—], a trimethylene group [—(CH2)3—], a tetramethylene group [—(CH2)4—], and a pentamethylene group [—(CH2)5—].
The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkylalkylene groups, for example, alkylmethylene groups such as —CH(CH3)—, —CH(CH2CH3)—, —C(CH3)2—, —C(CH3)(CH2CH3)—, —C(CH3)(CH2CH2CH3)—, and —C(CH2CH3)2—; alkylethylene groups such as —CH(CH3)CH2—, —CH(CH3)CH(CH3)—, —C(CH3)2CH2—, —CH(CH2CH3)CH2—, and —C(CH2CH3)2—CH2—; alkyltrimethylene groups such as —CH(CH3)CH2CH2—, and —CH2CH(CH3)CH2—; and alkyltetramethylene groups such as —CH(CH3)CH2CH2CH2—, and —CH2CH(CH3)CH2CH2—. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
Examples of the aliphatic hydrocarbon group containing a ring in the structure thereof include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group obtained by bonding the alicyclic hydrocarbon group to the terminal of a linear or branched aliphatic hydrocarbon group, and a group obtained by interposing the alicyclic hydrocarbon group is in a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same one as the above-described linear aliphatic hydrocarbon group or the above-described branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably a monocycloalkane having 3 to 12 carbon atoms, more preferably a monocycloalkane having 3 to 8 carbon atoms, and still more preferably a monocycloalkane having 5 to 6 carbon atoms. Specific examples of the monocycloalkane include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably a group having 7 to 12 carbon atoms. Specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The aromatic hydrocarbon group as the divalent hydrocarbon group represented by Va1 is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. Here, the number of carbon atoms in a substituent is not included in the number of carbon atoms.
Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring obtained by substituting part of carbon atoms constituting the above-described aromatic hydrocarbon rings with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the above-described aromatic hydrocarbon ring (an arylene group); and a group in which one hydrogen atom of a group (an aryl group) formed by removing one hydrogen atom from the aromatic hydrocarbon ring has been substituted with an alkylene group (for example, a group in which one hydrogen atom have been removed from an aryl group in arylalkyl groups such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The alkylene group (an alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.
In General Formula (a1-1), Ra1 is an acid dissociable group represented by General Formula (a1-r-1) or (a1-r-2).
In General Formula (a1-2), the (na2+1)-valent hydrocarbon group as Wa1 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group indicates a hydrocarbon group that has no aromaticity and may be saturated or unsaturated. In general, it is preferable that the aliphatic hydrocarbon group is saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure thereof, and a combination of the linear or branched aliphatic hydrocarbon group and the aliphatic hydrocarbon group containing a ring in the structure thereof.
The valency of (na2+1) is preferably divalent, trivalent, or tetravalent, and more preferably divalent or trivalent.
In General Formula (a1-2), Ra2 is an acid dissociable group represented by General Formula (a1-r-1) or (a1-r-3).
Specific examples of the constitutional unit represented by General Formula (a1-1) are shown below. In each of the formulae shown below, Ra represents a hydrogen atom, a methyl group, or a trifluoromethyl group.
Specific examples of the constitutional unit represented by General Formula (a1-2) are shown below.
The constitutional unit (a1) contained in the component (A1) may be one kind or may be two or more kinds.
The constitutional unit (a1) is more preferably a constitutional unit represented by General Formula (a1-1) since lithography characteristics (sensitivity, shape, and the like) in lithography depending on an electron beam or EUV can be more easily increased.
Among these, the constitutional unit (a1) particularly preferably includes a constitutional unit represented by General Formula (a1-1-1) shown below.
[In the formula, Ra1″ is an acid dissociable group represented by General Formula (a1-r2-1), (a1-r2-3), or (a1-r2-4).]
In General Formula (a1-1-1), R, Va1, and na1 are each the same as R, Va1, and na1 in General Formula (a1-1).
The description for the acid dissociable group represented by General Formula (a1-r2-1), (a1-r2-3), or (a1-r2-4) is as described above. Among them, it is preferable to select an acid dissociable group represented by General Formula (a1-r2-1) and more preferable to select an acid dissociable group in which the carbon atom to which Ra′10 is bonded and Ra′11 form an aliphatic cyclic group since it is suitable due to the reason that the reactivity can be enhanced for the use in EB or EUV.
The proportion of the constitutional unit (a1) in the component (A1) is preferably in a range of 30% to 75% by mole, more preferably in a range of 35% to 70% by mole, and still more preferably in a range of 40% to 60% by mole, with respect to the total (100% by mole) of all constitutional units constituting the component (A1).
In a case where the proportion of the constitutional unit (a1) is equal to or larger than the lower limit value of the preferred range described above, lithography characteristics such as sensitivity, resolution, and roughness amelioration are improved. On the other hand, in a case where it is equal to or smaller than the upper limit value of the above preferred range, balance with other constitutional units can be obtained, and various lithography characteristics are improved.
In regard to constitutional unit (a10)
The constitutional unit (a10) is a constitutional unit represented by General Formula (a10-1).
[In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Yax1 represents a single bond or a divalent linking group. Wax1 represents an (nax1+1)-valent aromatic hydrocarbon group. nax1 represents an integer of 1 or more.]
In General Formula (a10-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms as R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
The halogenated alkyl group having 1 to 5 carbon atoms as R is a group obtained by substituting part or all of hydrogen atoms of an above-described alkyl group having 1 to 5 carbon atoms with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and, an iodine atom, and a fluorine atom is particularly preferable.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and in terms of industrial availability, R is more preferably a hydrogen atom, a methyl group, or trifluoromethyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.
In General Formula (a10-1), Yax1 represents a single bond or a divalent linking group.
The descriptions for the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom, as Yax1 are each the same as the descriptions for the divalent hydrocarbon group which may have a substituent, and the divalent linking group containing a hetero atom, as Ya01, in General Formula (a0-1) described above.
Among the above, Yax1 is preferably a single bond, an ester bond [—C(═O)—O—, —O—C(═O)—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond or an ester bond [—C(═O)—O—, —O—C(═O)—].
In General Formula (a10-1), Wax1 represents an (nax1+1)-valent aromatic hydrocarbon group.
Examples of the aromatic hydrocarbon group as Wax1 include a group obtained by removing (nax1+1) hydrogen atoms from an aromatic ring. Here, the aromatic ring is not particularly limited as long as it is a cyclic conjugated system having (4n+2) π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings obtained by substituting part of carbon atoms constituting the above-described aromatic hydrocarbon ring with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.
Examples of the aromatic hydrocarbon group as Wax1 also include a group obtained by removing (nax1+1) hydrogen atoms from an aromatic compound including two or more aromatic rings (for example, biphenyl and fluorene).
Among the above, Wax1 is preferably a group in which (nax1+1) hydrogen atoms have been removed from benzene, naphthalene, anthracene, or biphenyl, more preferably a group in which (nax1+1) hydrogen atoms have been removed from benzene or naphthalene, and still more preferably a group in which (nax1+1) hydrogen atoms have been removed from benzene.
In General Formula (a10-1), nax1 represents an integer of 1 or more, preferably an integer in a range of 1 to 10, more preferably an integer in a range of 1 to 5, still more preferably 1, 2, or 3, and particularly preferably 1 or 2.
Specific examples of the constitutional unit (a10) represented by General Formula (a10-1) are shown below.
In each of the formulae shown below, Ra represents a hydrogen atom, a methyl group, or a trifluoromethyl group.
The constitutional unit (a10) contained in the component (A1) may be one kind or may be two or more kinds.
In a case where the component (A1) has the constitutional unit (a10), the proportion of the constitutional unit (a10) in the component (A1) is preferably in a range of 5% to 35% by mole, more preferably in a range of 10% to 30% by mole, and still more preferably in a range of 15% to 25% by mole, with respect to the total (100% by mole) of all constitutional units constituting the component (A1).
In a case where the proportion of the constitutional unit (a10) is equal to or larger than the lower limit value of the above preferred range, the sensitivity is more easily increased in the formation of the resist pattern. On the other hand, in a case where it is equal to or smaller than the upper limit value of the above preferred range, balance with other constitutional units can be obtained, and various lithography characteristics are improved.
In regard to constitutional unit (a2)
The constitutional unit (a2) is a constitutional unit containing a lactone-containing cyclic group, a —SO2-containing cyclic group, or a carbonate-containing cyclic group (provided that constitutional units corresponding to the constitutional unit (a0) and the constitutional unit (a1) are excluded)
The component (A1) may further have the constitutional unit (a2) in addition to the constitutional unit (a0) or in addition to the constitutional unit (a0) and the constitutional unit (a1).
In a case where the component (A1) is used for forming a resist film, the lactone-containing cyclic group, the —SO2-containing cyclic group, or the carbonate-containing cyclic group in the constitutional unit (a2) is effective for improving the adhesiveness of the resist film to the substrate. Further, due to having the constitutional unit (a2), lithography characteristics can be improved, for example, by the effects obtained by appropriately adjusting the acid diffusion length, increasing the adhesiveness of the resist film to the substrate, and appropriately adjusting the solubility during development.
The “lactone-containing cyclic group” indicates a cyclic group that contains a ring (lactone ring) containing a —O—C(═O)— in the ring skeleton. In a case where the lactone ring is counted as the first ring and the group contains only the lactone ring, the group is referred to as a monocyclic group. Further, in a case where the group has other ring structures, the group is referred to as a polycyclic group regardless of the structures. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone-containing cyclic group for the constitutional unit (a2) is not particularly limited, and any lactone-containing cyclic group may be used. Specific examples thereof include groups each represented by General Formulae (a2-r-1) to (a2-r-7) shown below.
[In the formulae, Ra′21s each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group, or a cyano group; R″ represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO2-containing cyclic group; A″ represents an oxygen atom, a sulfur atom, or an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom (—O—) or a sulfur atom (—S—); and n′ represents an integer in a range of 0 to 2, and m′ is 0 or 1.]
In General Formulae (a2-r-1) to (a2-r-7), the alkyl group as Ra′21 is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably a linear alkyl group or a branched alkyl group. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group as Ra′21 is preferably an alkoxy group having 1 to 6 carbon atoms. Further, the alkoxy group is preferably a linear or branched alkoxy group. Specific examples of the alkoxy groups include a group formed by linking the above-described alkyl group mentioned as the alkyl group represented by Ra′21 to an oxygen atom (—O—).
Examples of the halogen atom as Ra′21 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferable.
Examples of the halogenated alkyl group as Ra′21 include a group obtained by substituting part or all of hydrogen atoms in the above-described alkyl group as Ra′21 with the above-described halogen atoms. The halogenated alkyl group is preferably a fluorinated alkyl group and particularly preferably a perfluoroalkyl group.
In —COOR″ and —OC(═O)R″ as Ra′21, R″ represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO2-containing cyclic group.
The alkyl group as R″ may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms.
In a case where R″ represents a linear or branched alkyl group, it is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group.
In a case where R″ represents a cyclic alkyl group, the cyclic alkyl group preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and particularly preferably 5 to 10 carbon atoms. Specific examples thereof include a group obtained by removing one or more hydrogen atoms from a monocycloalkane, which may be or may not be substituted with a fluorine atom or a fluorinated alkyl group; and a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as bicycloalkane, tricycloalkane, or tetracycloalkane. More specific examples thereof include a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane; and a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane.
Examples of the lactone-containing cyclic group as R″ include the same ones as the groups each represented by General Formulae (a2-r-1) to (a2-r-7).
The carbonate-containing cyclic group as R″ is the same as the carbonate-containing cyclic group described below. Specific examples thereof include groups each represented by General Formulae (ax3-r-1) to (ax3-r-3).
The —SO2-containing cyclic group as R″ is the same a —SO2-containing cyclic group described below. Specific examples thereof include groups each represented by General Formulae (a5-r-1) to (a5-r-4).
The hydroxyalkyl group as Ra′21 preferably has 1 to 6 carbon atoms, and specific examples thereof include a group obtained by substituting at least one hydrogen atom in the alkyl group as Ra′21 with a hydroxyl group.
In General Formulae (a2-r-2), (a2-r-3) and (a2-r-5), as the alkylene group having 1 to 5 carbon atoms as A″, a linear or branched alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. Specific examples of the alkylene groups that contain an oxygen atom or a sulfur atom include a group obtained by interposing —O— or —S— in the terminal of the alkylene group or between the carbon atoms of the alkylene group, and examples thereof include —O—CH2—, —CH2—O—CH2—, —S—CH2—, and —CH2—S—CH2—. A″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
Specific examples of the groups each represented by General Formulae (a2-r-1) to (a2-r-7) are shown below.
The “—SO2-containing cyclic group” indicates a cyclic group having a ring containing —SO2— in the ring skeleton thereof. Specifically, it is a cyclic group in which the sulfur atom (S) in —SO2— forms a part of the ring skeleton of the cyclic group. In a case where the ring containing —SO2— in the ring skeleton thereof is counted as the first ring and the group contains only the ring, the group is referred to as a monocyclic group. In a case where the group further has other ring structures, the group is referred to as a polycyclic group regardless of the ring structures. The —SO2-containing cyclic group may be a monocyclic group or a polycyclic group.
The —SO2-containing cyclic group is particularly preferably a cyclic group containing —O—SO2— in the ring skeleton thereof, in other words, a cyclic group containing a sultone ring in which —O—S— in the —O—SO2— group forms a part of the ring skeleton thereof.
More specific examples of the —SO2-containing cyclic group include groups each represented by General Formulae (a5-r-1) to (a5-r-4) shown below.
[In the formulae, Ra′51s each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group, or a cyano group; R″ represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO2-containing cyclic group; A″ represents an oxygen atom, a sulfur atom, or an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom; and n′ represents an integer in a range of 0 to 2.]
In General Formulae (a5-r-1) and (a5-r-2), A″ has the same definition as that for A″ in General Formulae (a2-r-2), (a2-r-3) and (a2-r-5).
Examples of the alkyl group, the alkoxy group, the halogen atom, the halogenated alkyl group, —COOR″, —OC(═O)R″, and the hydroxyalkyl group as Ra′51 include the same ones as those each mentioned in the explanation of Ra′21 in General Formulae (a2-r-1) to (a2-r-7).
Specific examples of the groups each represented by General Formulae (a5-r-1) to (a5-r-4) are shown below. In the formulae shown below, “Ac” represents an acetyl group.
The “carbonate-containing cyclic group” indicates a cyclic group having a ring (a carbonate ring) containing —O—C(═O)—O— in the ring skeleton thereof. In a case where the carbonate ring is counted as the first ring and the group contains only the carbonate ring, the group is referred to as a monocyclic group. Further, in a case where the group has other ring structures, the group is referred to as a polycyclic group regardless of the structures. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
The carbonate ring-containing cyclic group is not particularly limited, and any carbonate ring-containing cyclic group may be used. Specific examples thereof include groups each represented by General Formulae (ax3-r-1) to (ax3-r-3) shown below.
[In the formulae, Ra′x31s independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group, or a cyano group; R″ represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO2-containing cyclic group; A″ represents an oxygen atom, a sulfur atom, or an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom; and p′ represents an integer in a range of 0 to 3, and q′ is 0 or 1.]
In General Formulae (ax3-r-2) and (ax3-r-3), A″ has the same definition as that for A″ in General Formulae (a2-r-2), (a2-r-3) and (a2-r-5).
Examples of the alkyl group, the alkoxy group, the halogen atom, the halogenated alkyl group, —COOR″, —OC(═O)R″, and the hydroxyalkyl group as Ra′31 include the same ones as those each mentioned in the explanation of Ra′21 in General Formulae (a2-r-1) to (a2-r-7).
Specific examples of the groups each represented by General Formulae (ax3-r-1) to (ax3-r-3) are shown below.
Among them, the constitutional unit (a2) is preferably a constitutional unit derived from acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent.
The constitutional unit (a2) is preferably a constitutional unit represented by General Formula (a2-1).
[In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya21 represents a single bond or a divalent linking group. La21 represents —O—, —COO—, —CON(R′)—, —OCO—, —CONHCO— or —CONHCS—, and R′ represents a hydrogen atom or a methyl group. However, in a case where La21 represents —O—, Ya21 does not represent —CO—. Ra21 represents a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO2-containing cyclic group.]
In General Formula (a2-1), R has the same definition as described above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and particularly preferably a hydrogen atom or a methyl group in terms of industrial availability.
In General Formula (a2-1), the divalent linking group as Ya21 is not particularly limited, and suitable examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group having a hetero atom.
The descriptions for the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom, as Ya21 are each the same as the descriptions for the divalent hydrocarbon group which may have a substituent, and the divalent linking group containing a hetero atom, as Ya01, in General Formula (a0-1) described above.
Among the above, Ya21 is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof.
In General Formula (a2-1), Ra21 represents a lactone-containing cyclic group, a —SO2-containing cyclic group, or a carbonate-containing cyclic group.
Suitable examples of the lactone-containing cyclic group, the —SO2-containing cyclic group, and the carbonate-containing cyclic group as Ra21 include groups each represented by General Formulae (a2-r-1) to (a2-r-7), groups each represented by General Formulae (a5-r-1) to (a5-r-4), and groups each represented by General Formulae (ax3-r-1) to (ax3-r-3) described above.
Among them, a lactone-containing cyclic group or a —SO2-containing cyclic group is preferable, and any one of groups each represented by General Formula (a2-r-1), (a2-r-2), (a2-r-6), or (a5-r-1) is preferable. Specifically, groups each represented by any one of Chemical Formulae (r-1c-1-1) to (r-1c-1-7), (r-1c-2-1) to (r-1c-2-18), (r-1c-6-1), (r-s1-1-1), and (r-s1-1-18) are more preferable.
The constitutional unit (a2) contained in the component (A1) may be one kind or may be two or more kinds.
In a case where the component (A1) has the constitutional unit (a2), the proportion of the constitutional unit (a2) is preferably in a range of 1% to 25% by mole, more preferably in a range of 2% to 20% by mole, and still more preferably in a range of 5% to 15% by mole, with respect to the total (100% by mole) of all constitutional units constituting the component (A1).
In a case where the proportion of the constitutional unit (a2) is equal to or larger than the lower limit value of the preferred range, the effect obtained by allowing the constitutional unit (a2) to be contained can be sufficiently achieved by the effect described above. In a case where it is equal to or smaller than the upper limit value of the preferred range, the balance with other constitutional units can be obtained, and various lithography characteristics are improved.
In regard to constitutional unit (a3)
The constitutional unit (a3) is a constitutional unit containing a polar group-containing aliphatic hydrocarbon group (provided that a constitutional unit corresponding to the constitutional unit (a1) or the constitutional unit (a2) is excluded). In a case where the component (A1) has the constitutional unit (a3), the hydrophilicity of the component (A) is increased, which contributes to an improvement in resolution. Further, acid diffusion length can be appropriately adjusted.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group obtained by substituting part of hydrogen atoms of the alkyl group with a fluorine atom, and the polar group is particularly preferably a hydroxyl group.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group (preferably an alkylene group) having 1 to 10 carbon atoms, and a cyclic aliphatic hydrocarbon group (a cyclic group). The cyclic group may be a monocyclic group or a polycyclic group. For example, these cyclic groups can be appropriately selected from a large number of groups that have been proposed in resins for a resist composition for an ArF excimer laser.
In a case where the cyclic group is a monocyclic group, the monocyclic group preferably has 3 to 10 carbon atoms. Among them, a constitutional unit derived from an acrylic acid ester that includes an aliphatic monocyclic group containing a hydroxyl group, cyano group, carboxy group, or a hydroxyalkyl group obtained by substituting part of hydrogen atoms of the alkyl group with a fluorine atom are particularly preferable. Examples of the monocyclic group include a group obtained by removing two or more hydrogen atoms from a monocycloalkane. Specific examples of the monocyclic group include a group obtained by removing two or more hydrogen atoms from a monocycloalkane such as cyclopentane, cyclohexane, or cyclooctane. Among these monocyclic groups, a group obtained by removing two or more hydrogen atoms from cyclopentane or a group obtained by removing two or more hydrogen atoms from cyclohexane are industrially preferable.
In a case where the cyclic group is a polycyclic group, the polycyclic group preferably has 7 to 30 carbon atoms. Among them, a constitutional unit derived from an acrylic acid ester that includes an aliphatic polycyclic group containing a hydroxyl group, cyano group, carboxy group, or a hydroxyalkyl group obtained by substituting part of hydrogen atoms of the alkyl group with a fluorine atom is particularly preferable. Examples of the polycyclic group include groups obtained by removing two or more hydrogen atoms from a bicycloalkane, tricycloalkane, tetracycloalkane, or the like. Specific examples thereof include a group obtained by removing two or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Among these polycyclic groups, a group obtained by removing two or more hydrogen atoms from adamantane, a group obtained by removing two or more hydrogen atoms from norbornane, or a group obtained by removing two or more hydrogen atoms from tetracyclododecane are industrially preferable.
The constitutional unit (a3) is not particularly limited, and any constitutional unit may be used as long as the constitutional unit contains a polar group-containing aliphatic hydrocarbon group.
The constitutional unit (a3) is preferably a constitutional unit derived from an acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, where the constitutional unit contains a polar group-containing aliphatic hydrocarbon group.
In a case where the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the constitutional unit (a3) is preferably a constitutional unit derived from a hydroxyethyl ester of acrylic acid.
In addition, in a case where the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, preferred examples of the constitutional unit (a3) include a constitutional unit represented by General Formula (a3-1), a constitutional unit represented by General Formula (a3-2), and a constitutional unit represented by General Formula (a3-3) shown below; and in a case where the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a monocyclic group, preferred examples of thereof include a constitutional unit represented by General Formula (a3-4).
[In the formulae, R has the same definition as described above, j represents an integer in a range of 1 to 3, k represents an integer in a range of 1 to 3, t′ represents an integer in a range of 1 to 3, 1 represents an integer in a range of 0 to 5, and s represents an integer in a range of 1 to 3.]
In General Formula (a3-1), j is preferably 1 or 2 and more preferably 1. In a case where j represents 2, it is preferable that the hydroxyl groups are bonded to the 3-position and the 5-position of the adamantyl group. In a case where j represents 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
It is preferable that j represents 1, and it is particularly preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
In General Formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5-position or 6-position of the norbornyl group.
In General Formula (a3-3), it is preferable that t′ represents 1. It is preferable that 1 represents 1. It is preferable that s represents 1. Further, it is preferable that a 2-norbornyl group or 3-norbornyl group is bonded to the terminal of the carboxy group of the acrylic acid. It is preferable that the fluorinated alkyl alcohol is bonded to the 5-position or 6-position of the norbornyl group.
In General Formula (a3-4), it is preferable that t′ represents 1 or 2. It is preferable that 1 represents 0 or 1. It is preferable that s represents 1. It is preferable that the fluorinated alkyl alcohol is bonded to the 3-position or 5-position of the cyclohexyl group.
The constitutional unit (a3) contained in the component (A1) may be one kind or may be two or more kinds.
In a case where the component (A1) has the constitutional unit (a3), the proportion of the constitutional unit (a3) in the component (A1) is preferably in a range of 1% to 25% by mole, more preferably in a range of 2% to 20% by mole, and still more preferably in a range of 5% to 15% by mole, with respect to the total (100% by mole) of all constitutional units constituting the component (A1).
In a case where the proportion of the constitutional unit (a3) is equal to or larger than the lower limit value of the above preferred range, the effect obtained by allowing the constitutional unit (a3) to be contained can be sufficiently achieved by the effect described above. On the other hand, in a case where it is equal to or smaller than the upper limit value of the above preferred range, the balance with other constitutional units can be obtained, and various lithography characteristics are improved.
In regard to constitutional unit (a4)
The constitutional unit (a4) is a constitutional unit containing an acid non-dissociable aliphatic cyclic group. In a case where the component (A1) has the constitutional unit (a4), the dry etching resistance of the formed resist pattern is improved. Further, the hydrophobicity of the component (A) increases. The improvement in hydrophobicity contributes to the improvement in resolution, a resist pattern shape, and the like, particularly in the case of a solvent developing process.
The “acid non-dissociable cyclic group” in the constitutional unit (a4) is a cyclic group that remains in the constitutional unit without being dissociated even in a case where an acid acts in a case where the acid is generated in the resist composition upon exposure (for example, in a case where an acid is generated from the constitutional unit that generates acid upon exposure, or the component (B) described later).
Examples of the constitutional unit (a4) preferably include a constitutional unit derived from an acrylic acid ester including an acid non-dissociable aliphatic cyclic group. As the cyclic group, many cyclic groups known in the related art as cyclic groups used as a resin component of a resist composition for an ArF excimer laser, a KrF excimer laser (preferably an ArF excimer laser), or the like can be used.
The cyclic group is particularly preferably at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group, from the viewpoint of industrial availability. These polycyclic groups may have, as a substituent, a linear or branched alkyl group having 1 to 5 carbon atoms.
Specific examples of the constitutional unit (a4) include constitutional units each represented by General Formulae (a4-1) to (a4-7).
In each of the formulae shown below, Ra represents a hydrogen atom, a methyl group, or a trifluoromethyl group.
The constitutional unit (a4) contained in the component (A1) may be one kind or may be two or more kinds.
In a case where the component (A1) has the constitutional unit (a4), the proportion of the constitutional unit (a4) in the component (A1) is preferably in a range of 1% to 25% by mole, more preferably in a range of 2% to 20% by mole, and still more preferably in a range of 5% to 15% by mole, with respect to the total (100% by mole) of all constitutional units constituting the component (A1).
In a case where the proportion of the constitutional unit (a4) is equal to or larger than the lower limit value of the above preferred range, the effect obtained by allowing the constitutional unit (a4) to be contained can be sufficiently achieved. On the other hand, in a case where it is equal to or smaller than the upper limit value of the above preferred range, the balance with other constitutional units can be obtained, and various lithography characteristics are improved.
In regard to constitutional unit derived from styrene and constitutional unit derived from styrene derivative (hereinafter, these are collectively written as “constitutional unit (st)”)
The “styrene” is a concept including those obtained by substituting a hydrogen atom of styrene and a hydrogen atom at the α-position of styrene with other substituents such as an alkyl group and a halogenated alkyl group. The alkyl group as the substituent herein includes an alkyl group having 1 to 5 carbon atoms, and the halogenated alkyl group as the substituent includes a halogenated alkyl group having 1 to 5 carbon atoms.
Examples of the “styrene derivatives” include those obtained by bonding a substituent to a benzene ring of styrene in which a hydrogen atom at the α-position may be substituted with a substituent.
Here, the α-position (carbon atom at the α-position) indicates the carbon atom having the benzene ring bonded thereto, unless otherwise specified.
The “constitutional unit derived from styrene” or the “constitutional unit derived from a styrene derivative” indicates a constitutional unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.
The constitutional unit (st) contained in the component (A1) may be one kind or may be two or more kinds.
In a case where the component (A1) has the constitutional unit (st), the proportion of the constitutional unit (st) is preferably in a range of 1% to 30% by mole and more preferably in a range of 3% to 20% by mole with respect to the total (100% by mole) of all constitutional units constituting the component (A1).
The component (A1) contained in the resist composition may be used alone or in a combination of two or more kinds thereof.
In the resist composition according to the present embodiment, examples of the component (A1) include a polymeric compound having a repeating structure of the constitutional unit (a0).
Examples of the preferred component (A1) include a polymeric compound having a repeating structure of the constitutional unit (a0) and the constitutional unit (a1).
Specifically, as the component (A1), a polymeric compound consisting of a repeating structure of a constitutional unit (a0) and a constitutional unit (a1), or a polymeric compound consisting of repeating structure of a constitutional unit (a0), a constitutional unit (a1), and a constitutional unit (a10) can be suitably used.
The component (A1) can be produced by dissolving, in a polymerization solvent, each monomer from which the constitutional unit is derived, adding thereto a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (for example, V-601) to carry out polymerization.
Alternatively, the component (A1) can be produced by dissolving, in a polymerization solvent, a monomer from which the constitutional unit (a0) is derived and, as necessary, a monomer from which a constitutional unit other than the constitutional unit (a0) is derived, adding thereto a radical polymerization initiator such as described above to carry out polymerization, and then carrying out a deprotection reaction.
Further, a —C(CF3)2—OH group may be introduced into the terminal of the component (A1) during the polymerization using a chain transfer agent such as HS—CH2—CH2—CH2—C(CF3)2—OH in combination. As described above, a copolymer into which a hydroxyalkyl group, formed by substitution of part of hydrogen atoms in the alkyl group with a fluorine atom, has been introduced is effective for reducing development defects and reducing line edge roughness (LER: uneven irregularities of a line side wall).
The weight average molecular weight (Mw) (based on the polystyrene-equivalent value determined by gel permeation chromatography (GPC)) of the component (A1), which is not particularly limited, is preferably in a range of 1,000 to 50,000, more preferably in a range of 2,000 to 30,000, and still more preferably in a range of 3,000 to 20,000.
In a case where Mw of the component (A1) is equal to or smaller than the upper limit value of the above preferred range, a resist solvent solubility sufficient to be used as a resist is exhibited. On the other hand, in a case where it is equal to or larger than the lower limit value of the above preferred range, dry etching resistance and the cross-sectional shape of the resist pattern become excellent.
Further, the polydispersity (Mw/Mn) of the component (A1) is not particularly limited; however, it is preferably in a range of 1.0 to 4.0, more preferably in a range of 1.0 to 3.0, and particularly preferably in a range of 1.0 to 2.0. Mn represents the number average molecular weight.
In regard to base material components other than component (A1)
In the resist composition according to the present embodiment, a base material component having a solubility in a developing solution, which is changed under action of acid, which does not correspond to the component (A1), may be used in combination as the component (A).
The base material component which does not correspond to the component (A1) is not particularly limited, many components known in the related art as base material components for a chemically amplified resist composition can be randomly selected, and one kind of a polymeric compound or a low molecular weight compound may be used alone or in combination of two or more kinds thereof.
The content of the component (A) in the resist composition according to the present embodiment may be adjusted depending on the resist film thickness to be formed.
<Photodecomposable Base (D0)>
The resist composition according to the present embodiment contains the component (A1) and the photodecomposable base (the component (D0)) that controls the diffusion of the acid generated upon exposure.
The component (D0) is a component in which the acid dissociation constant (pKa) of the conjugate acid of 4.0 or less.
Here, the “pKa” is an acid dissociation constant, which is generally used as an index indicating the acid strength of the target substance. The pKa value of the conjugate acid of the component (D0) can be determined by measurement according to the conventional method. Further, the pKa value of the conjugate acid of the component (D0) can also be calculated from the simulation using known software such as “ACD/Labs” (product name, manufactured by Advanced Chemistry Development Inc.).
The pKa of the conjugate acid of the component (D0) (calculated by the above-described “ACD/Labs” software) is 4.0 or less, the pKa is preferably 3.8 or less, the pKa is more preferably in a range of 0.1 to 3.5, and the pKa is still more preferably in a range of 0.3 to 3.3.
In a case where the pKa of the conjugate acid of the component (D0) is equal to or smaller than the upper limit value of the above preferred range, a better pattern shape can be easily obtained in the resist pattern formation. On the other hand, in a case where the pKa of the conjugate acid of the component (D0) is equal to or larger than the lower limit value of the above preferred range, the sensitivity and the resolution are easily enhanced.
Examples of the preferred (D0) component include a compound represented by General Formula (d0-1).
[In the formula, Rd0 represents a substituent. q0 represents an integer in a range of 0 to 3. n0 represents an integer of 1 or more. p0 represents an integer of 0 or more. In a case where p0 is 2 or more, a plurality of Rd0's may be the same or different from each other. However, the following is satisfied; n0+p0 5 (q0×2)+5. m represents an integer of 1 or more, and Mm+ represents an m-valent organic cation.]
Anion moiety in compound represented by General Formula (d0-1) In General Formula (d0-1), Rd0 represents a substituent. Examples of the substituent include a hydrocarbon group, an alkoxy group, an acyl group, and a hydroxyalkyl group.
Examples of the hydrocarbon group as the substituent include a linear or branched alkyl group, an aliphatic cyclic hydrocarbon group, and an aromatic hydrocarbon group.
The linear or branched alkyl group is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, and a pentyl group.
The aliphatic cyclic hydrocarbon group is preferably an aliphatic cyclic hydrocarbon group having 3 to 6 carbon atoms, and specific examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms, and specific examples thereof include a group obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene. Among the above, a group (a phenyl group) obtained by removing one hydrogen atom from benzene is more preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples thereof include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, a tert-butoxy group, and a pentyloxy group. Among them, a methoxy group is more preferable.
The acyl group as the substituent is preferably an acyl group having 1 to 3 carbon atoms, and specific examples thereof include a formyl group, an acetyl group, and a propionyl group.
The hydroxyalkyl group as the substituent is preferably a hydroxyalkyl group having 1 to 5 carbon atoms, and specific examples thereof include a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, and a hydroxypentyl group.
In General Formula (d0-1), q0 represents an integer in a range of 0 to 3. That is, in the anion moiety in General Formula (d0-1), a case where q0 is 0 gives a benzene structure, a case where q0 is 1 gives a naphthalene structure, a case where q0 is 2 gives an anthracene structure, and a case where q0 is 3 gives a tetracene structure. q0 is preferably 0 or 1 and more preferably 0.
In General Formula (d0-1), no represents an integer of 1 or more, and it is preferably an integer in a range of 1 to 3, more preferably 1 or 2, and still more preferably 2.
In General Formula (d0-1), p0 represents an integer of 0 or more. In a case where p0 is 2 or more, a plurality of Rdo's may be the same or different from each other. p0 is preferably an integer in a range of 0 to 3, more preferably an integer in a range of 0 to 2, still more preferably 0 or 1, and particularly preferably 0.
In General Formula (d0-1), the following is satisfied; n0+p0≤(q0×2)+5.
In a case where q0 represents an integer in a range of 0 to 3, that is, in a case of the benzene structure, the naphthalene structure, the anthracene structure, or the tetracene structure, all hydrogen atoms other than the hydrogen atom substituted with a carboxylate group (—C(═O)O—) may be each substituted with the above substituent (Rd0) or a hydroxy group. However, the anion moiety in General Formula (d0-1) has at least one hydroxy group.
In addition, in the benzene structure, the naphthalene structure, the anthracene structure, or the tetracene structure, the substitution positions of the carboxylate group (—C(═O)O—), the above substituent (Rd0), and the hydroxy group are not particularly limited.
Specific examples of the preferred anion moiety in the compound represented by General Formula (d0-1) will be shown below. The acid dissociation constant (pKa) of the conjugate acid of the compound, where the conjugate acid matches with the anion moiety, is also shown.
Cation moiety in compound represented by General Formula (d0-1)
In General Formula (d0-1), m represents an integer of 1 or more, and Mm+ represents an m-valent organic cation.
Examples of the m-valent organic cation as Mm+ include m-valent onium cations. Among these, a sulfonium cation or an iodonium cation is preferable.
Preferred examples of the cation moiety ((Mm+)1/m) include organic cations each represented by General Formulae (ca-1) to (ca-5).
[In the formula, R201 to R207, R211, and R212 each independently represent an aryl group, an alkyl group, or an alkenyl group, each of which may have a substituent. R201 to R203, R206 and R207, or R211 and R212 may be bonded to each other to form a ring together with the sulfur atoms in the formulae. R208 and R209 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R210 represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a —SO2-containing cyclic group which may have a substituent. L201 represents —C(═O)— or —C(═O)—O—. Each Y201 independently represents an arylene group, an alkylene group, or an alkenylene group. x represents 1 or 2. W201 represents an (x+1)-valent linking group.]
In General Formulae (ca-1) to (ca-5), examples of the aryl group as R201 to R207, R211, and R212 include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferable.
The alkyl group as R201 to R207, R211, and R212 is a chain-like or cyclic alkyl group preferably having 1 to 30 carbon atoms.
The alkenyl group as R201 to R207, R211, and R212 preferably has 2 to 10 carbon atoms.
Examples of the substituent which may be contained in R201 to R207 and R210 to R212 include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups each represented by General Formulae (ca-r-1) to (ca-r-7) shown below.
[In the formulae, each R′201 independently represents a hydrogen atom, a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent.]
Cyclic group which may have substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group indicates a hydrocarbon group that has no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated. In general, it is preferable that the aliphatic hydrocarbon group is saturated.
The aromatic hydrocarbon group as R′201 is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. Here, the number of carbon atoms in a substituent is not included in the number of carbon atoms.
Specific examples of the aromatic ring contained in the aromatic hydrocarbon group as R′201 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and an aromatic heterocyclic ring obtained by substituting part of carbon atoms constituting one of these aromatic rings with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specific examples of the aromatic hydrocarbon group as R′201 include a group (an aryl group such as a phenyl group or a naphthyl group) obtained by removing one hydrogen atom from the above-described aromatic ring and a group (an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, 1-naphthylethyl group, or a 2-naphthylethyl group) obtained by substituting one hydrogen atom in the aromatic ring with an alkylene group. The alkylene group (an alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.
Examples of the cyclic aliphatic hydrocarbon group as R′201 include aliphatic hydrocarbon groups containing a ring in the structure thereof.
Examples of the aliphatic hydrocarbon group containing a ring in the structure thereof include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group obtained by bonding the alicyclic hydrocarbon group to the terminal of a linear or branched aliphatic hydrocarbon group, and a group obtained by interposing the alicyclic hydrocarbon group is in a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among the above, a polycycloalkane having a bridged ring-based polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or a polycycloalkane having a condensed ring-based polycyclic skeleton, such as a cyclic group having a steroid skeleton is preferable.
Among them, the cyclic aliphatic hydrocarbon group as R′201 is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane, more preferably a group obtained by removing one hydrogen atom from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.
The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms.
The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [—CH2—], an ethylene group [—(CH2)2—], a trimethylene group [—(CH2)3—], a tetramethylene group [—(CH2)4—], and a pentamethylene group [—(CH2)5—].
The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkylalkylene groups, for example, alkylmethylene groups such as —CH(CH3)—, —CH(CH2CH3)—, —C(CH3)2—, —C(CH3)(CH2CH3)—, —C(CH3)(CH2CH2CH3)—, and —C(CH2CH3)2—; alkylethylene groups such as —CH(CH3)CH2—, —CH(CH3)CH(CH3)—, —C(CH3)2CH2—, —CH(CH2CH3)CH2—, and —C(CH2CH3)2—CH2—; alkyltrimethylene groups such as —CH(CH3)CH2CH2—, and —CH2CH(CH3)CH2—; and alkyltetramethylene groups such as —CH(CH3)CH2CH2CH2—, and —CH2CH(CH3)CH2CH2—. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The cyclic hydrocarbon group as R′201 may contain a hetero atom such as a heterocyclic ring. Specific examples thereof include lactone-containing cyclic groups each represented by General Formulae (a2-r-1) to (a2-r-7), —SO2-containing cyclic groups each represented by General Formulae (a5-r-1) to (a5-r-4), and other heterocyclic groups each represented by Chemical Formulae (r-hr-1) to (r-hr-16).
Examples of the substituent of the cyclic group as R′201 include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is most preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group.
The halogen atom as the substituent is preferably a fluorine atom.
Examples of the halogenated alkyl group as the substituent include a group obtained by substituting part or all of hydrogen atoms in an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, with the above-described halogen atom.
The carbonyl group as the substituent is a group that is substituted for a methylene group (—CH2—) constituting the cyclic hydrocarbon group.
Chain-like alkyl group which may have substituent:
The chain-like alkyl group as R′201 may be linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples thereof include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.
Chain-like alkenyl group which may have substituent:
Such a chain-like alkenyl group as R′201 may be linear or branched, preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (an allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.
Among the above, the chain-like alkenyl group is preferably a linear alkenyl group, more preferably a vinyl group or a propenyl group, and particularly preferably a vinyl group.
Examples of the substituent in the chain-like alkyl group or alkenyl group as R′201, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, a cyclic group as R′201 or the like may be used.
As the cyclic group which may have a substituent, the chain-like alkyl group which may have a substituent, or the chain-like alkenyl group which may have a substituent, as R′201, a group that is the same as the acid dissociable group represented by above-described General Formula (a1-r-2) can be mentioned as the cyclic group which may have a substituent or the chain-like alkyl group which may have a substituent, in addition to the groups described above.
Among them, R′201 is preferably a cyclic group which may have a substituent and more preferably a cyclic hydrocarbon group which may have a substituent. More specific examples thereof preferably include a phenyl group; a naphthyl group; a group obtained by removing one or more hydrogen atoms from a polycycloalkane; any one of lactone-containing cyclic groups each represented by General Formulae (a2-r-1) to (a2-r-7); and any one of —SO2-containing cyclic groups each represented by General Formulae (a5-r-1) to (a5-r-4).
In General Formulae (ca-1) to (ca-5), in a case where R201 to R203, R206 and R207, or R211 and R212 are bonded to each other to form a ring with a sulfur atom in the formula, these groups may be bonded to each other via a hetero atom such as a sulfur atom, an oxygen atom or a nitrogen atom, or a functional group such as a carbonyl group, —SO—, —SO2—, —SO3—, —COO—, —CONH—, or —N(RN)— (here, RN represents an alkyl group having 1 to 5 carbon atoms). Regarding the ring to be formed, a ring containing a sulfur atom in a formula in the ring skeleton thereof is preferably a 3-membered to 10-membered ring and particularly preferably a 5-membered to 7-membered ring containing a sulfur atom. Specific examples of the ring to be formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.
R208 and R209 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms and are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In a case where R208 and R209 each independently represent an alkyl group, R208 and R209 may be bonded to each other to form a ring.
R210 represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a —SO2-containing cyclic group which may have a substituent.
Examples of the aryl group as R210 include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferable.
The alkyl group as R210, a chain-like or cyclic alkyl group having 1 to 30 carbon atoms is preferable.
The alkenyl group as R210 preferably has 2 to 10 carbon atoms.
The —SO2-containing cyclic group which may have a substituent, as R210, is preferably a “—SO2-containing polycyclic group”, and more preferably a group represented by General Formula (a5-r-1).
Y201s each independently represent an arylene group, an alkylene group, or an alkenylene group.
Examples of the arylene group as Y201 include groups obtained by removing one hydrogen atom from an aryl group exemplified as the aromatic hydrocarbon group as Yax0 described above.
Examples of the alkylene group and alkenylene group as Y201 include groups obtained by removing one hydrogen atom from the chain-like alkyl group or the chain-like alkenyl group as R′201 described above.
In General Formula (ca-4), x represents 1 or 2.
W201 represents an (x+1)-valent linking group, that is, a divalent or trivalent linking group.
The divalent linking group as W201 is preferably a divalent hydrocarbon group which may have a substituent, and as examples thereof include the same divalent hydrocarbon group, which may have a substituent, as Ya01 in General Formula (a0-1) described above. The divalent linking group as W201 may be linear, branched, or cyclic and is preferably cyclic. Among these, a group obtained by combining two carbonyl groups at both terminals of an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.
Examples of the trivalent linking group as W201 include a group obtained by removing one hydrogen atom from the above-described divalent linking group as W201 and a group obtained by bonding the divalent linking group to another divalent linking group. The trivalent linking group as W201 is preferably a group obtained by bonding two carbonyl groups to an arylene group.
Among the above, the cation moiety of the compound represented by General Formula (d0-1) is preferably a cation represented by General Formula (ca-d0-1).
[In the formula, Rd01 represents an aryl group having a fluorine atom or an aryl group having a fluorinated alkyl group. Rd02 and Rd03 each independently represent an aryl group which may have a substituent or are bonded to each other to form a ring together with a sulfur atom in the formula.]
In General Formula (ca-d0-1), Rd01 represents an aryl group having a fluorine atom or an aryl group having a fluorinated alkyl group. Examples of the aryl group include the same ones as the aryl groups as R201 to R203 in General Formula (ca-1). In addition, the fluorinated alkyl group is preferably a group obtained by substituting part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group with a fluorine atom, and a trifluoromethyl group is more preferable.
Rd02 and Rd03 each independently represent an aryl group which may have a substituent or are bonded to each other to form a ring together with a sulfur atom in the formula. The aryl group as Rb1 to Rb3 is the same as the aryl group as R201 to R203 in General Formula (ca-1) described above.
Examples of the ring formed by bonding Rb2 and Rb3 to each other together with a sulfur atom in the formula include the same one as the ring formed by bonding the aryl groups as R201 to R203 in General Formula (ca-1) to each other together with a sulfur atom in the formula.
Suitable cations represented by General Formula (ca-1) are shown below.
[In the formulae, g2 and g3 indicate the numbers of repetitions, g2 represents an integer in a range of 0 to 20, and g3 represents an integer in a range of 0 to 20.]
[In the formula, R″201 represents a hydrogen atom or a substituent, and the substituent is the same as the substituent exemplified as the substituent which may be contained in R201 to R207 and R210 to R212.]
Specific examples of the suitable cation represented by General Formula (ca-2) include a diphenyliodonium cation and a bis(4-tert-butylphenyl)iodonium cation.
Specific examples of the suitable cation represented by General Formula (ca-3) include cations each represented by General Formulae (ca-3-1) to (ca-3-6).
Specific examples of the suitable cation represented by General Formula (ca-4) include cations each represented by General Formulae (ca-4-1) and (ca-4-2).
Specific examples of the suitable cation represented by General Formula (ca-5) include cations each represented by General Formulae (ca-5-1) to (ca-5-3).
In the resist composition according to the present embodiment, the cation moiety of the compound represented by General Formula (d0-1) is, among the above, preferably the cation represented by General Formula (ca-1).
Specifically, a cation represented by any one of Chemical Formulae (ca-1-1) to (ca-1-93) and (ca-1-100) to (ca-1-114) is preferable, a cation represented by any one of Chemical Formulae (ca-1-100) to (ca-1-114) is more preferable, a cation represented by any one of Chemical Formulae (ca-1-100) to (ca-1-112) is still more preferable, and a cation represented by any one of Chemical Formulae (ca-1-100) to (ca-1-103) is particularly preferable.
In the resist composition according to the present embodiment, among the above, the component (D0) is preferably a compound represented by General Formula (d0-1-0).
[In the formula, Rd01 represents an aryl group having a fluorine atom or an aryl group having a fluorinated alkyl group. Rd02 and Rd03 each independently represent an aryl group which may have a substituent or are bonded to each other to form a ring together with a sulfur atom in the formula. Rd0 represents a substituent. q0 represents an integer in a range of 0 to 3. n0 represents an integer of 1 or more. p0 represents an integer of 0 or more. In a case where p0 is 2 or more, a plurality of Rd0's may be the same or different from each other. However, the following is satisfied; n0+p0≤(q0×2)+5.]
The description for Rd01a, Rd02, and Rd03 in General Formula (d0-1-0) is the same as the description for Rd01a, Rd02, and Rd03 in General Formula (ca-d0-1). The description for Rd0, q0, n0, and p0 in General Formula (d0-1-0) is the same as the description for Rd0, q0, n0, and p0 in General Formula (d0-1).
Preferred specific examples of the component (D0) are shown below. The acid dissociation constant (pKa) of the conjugate acid of the compound is also shown.
In the resist composition according to the present embodiment, the component (D0) may be used alone or in a combination of two or more kinds thereof.
The content of the component (D0) in the resist composition according to the present embodiment is preferably in a range of 1 to 50 parts by mass, more preferably in a range of 3 to 50 parts by mass, still more preferably in a range of 3 to 20 parts by mass, and particularly preferably in a range of 3 to 10 parts by mass, with respect to 100 parts by mass of the component (A).
In a case where the content of the component (D0) is set within the above-described preferred range, the solubility of the developing solution in exposed portions of the resist film is enhanced, and thus the sensitivity and the resolution are further improved.
<Other Components>
The resist composition according to the present embodiment may further contain other components in addition to the component (A1) and the component (D0) described above. Examples of the other components include a component (B), a component (D) (provided that the component (D0) is excluded), a component (E), a component (F), and a component (S), which are described below.
<<Acid Generator Component (B)>>
The resist composition according to the present embodiment may further contain an acid generator component (B) (hereinafter, referred to as a “component (B)”) that generates acid upon exposure.
The component (B) is not particularly limited, and those which have been proposed so far as an acid generator for a chemically amplified resist composition in the related art can be used.
Examples of such an acid generator are numerous and include an onium salt-based acid generator such as an iodonium salt or a sulfonium salt; an oxime sulfonate-based acid generator; diazomethane-based acid generators such as bisalkyl or bisaryl sulfonyl diazomethanes and a poly(bis-sulfonyl)diazomethane; a nitrobenzylsulfonate-based acid generator; an iminosulfonate-based acid generator; and a disulfone-based acid generator.
Examples of the onium salt-based acid generator include a compound represented by General Formula (b-1) (hereinafter, also referred to as a “component (b-1)”), a compound represented by General Formula (b-2) (hereinafter, also referred to as a “component (b-2)”), and a compound represented by General Formula (b-3) (hereinafter, also referred to as a “component (b-3)”).
[In the formulae, R101 and R104 to R108 each independently represent a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. R104 and R105 may be bonded to each other to form a ring structure. R102 represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y101 represents a divalent linking group containing an oxygen atom or a single bond. V101 to V103 each independently represent a single bond, an alkylene group, or a fluorinated alkylene group. L101 and L102 each independently represent a single bond or an oxygen atom. L103 to L105 each independently represent a single bond, —CO—, or —SO2—. m represents an integer of 1 or more, and M′m+ represents an m-valent onium cation.]
{Anion Moiety}
Anion in component (b-1)
[In General Formula (b-1), R101 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent.
Cyclic group which may have substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group indicates a hydrocarbon group that has no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated. In general, it is preferable that the aliphatic hydrocarbon group is saturated.
The aromatic hydrocarbon group as R101 represents a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. Here, the number of carbon atoms in a substituent is not included in the number of carbon atoms.
Specific examples of the aromatic ring contained in the aromatic hydrocarbon group as R101 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and an aromatic heterocyclic ring obtained by substituting part of carbon atoms constituting one of these aromatic rings with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specific examples of the aromatic hydrocarbon group as R101 include a group (an aryl group such as a phenyl group or a naphthyl group) obtained by removing one hydrogen atom from the above-described aromatic ring and a group (an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, 1-naphthylethyl group, or a 2-naphthylethyl group) obtained by substituting one hydrogen atom in the aromatic ring with an alkylene group. The alkylene group (an alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.
Examples of the cyclic aliphatic hydrocarbon group as R101 include aliphatic hydrocarbon groups containing a ring in the structure thereof.
Examples of the aliphatic hydrocarbon group containing a ring in the structure thereof include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group obtained by bonding the alicyclic hydrocarbon group to the terminal of a linear or branched aliphatic hydrocarbon group, and a group obtained by interposing the alicyclic hydrocarbon group is in a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among the above, a polycycloalkane having a bridged ring-based polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or a polycycloalkane having a condensed ring-based polycyclic skeleton, such as a cyclic group having a steroid skeleton is preferable.
Among them, the cyclic aliphatic hydrocarbon group as R101 is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane, more preferably a group obtained by removing one hydrogen atom from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.
The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [—CH2—], an ethylene group [—(CH2)2—], a trimethylene group [—(CH2)3—], a tetramethylene group [—(CH2)4—], and a pentamethylene group [—(CH2)5—].
The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkylalkylene groups, for example, alkylmethylene groups such as —CH(CH3)—, —CH(CH2CH3)—, —C(CH3)2—, —C(CH3)(CH2CH3)—, —C(CH3)(CH2CH2CH3)—, and —C(CH2CH3)2—; alkylethylene groups such as —CH(CH3)CH2—, —CH(CH3)CH(CH3)—, —C(CH3)2CH2—, —CH(CH2CH3)CH2—, and —C(CH2CH3)2—CH2—; alkyltrimethylene groups such as —CH(CH3)CH2CH2—, and —CH2CH(CH3)CH2—; and alkyltetramethylene groups such as —CH(CH3)CH2CH2CH2—, and —CH2CH(CH3)CH2CH2—. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The cyclic hydrocarbon group as R101 may contain a hetero atom such as a heterocyclic ring. Specific examples thereof include lactone-containing cyclic groups each represented by General Formulae (a2-r-1) to (a2-r-7), —SO2-containing cyclic groups each represented by General Formulae (a5-r-1) to (a5-r-4), and other heterocyclic groups each represented by Chemical Formulae (r-hr-1) to (r-hr-16). In the formulae, * represents a bonding site that is bonded to Y101 in General Formula (b-1).
Examples of the substituent of the cyclic group as R101 include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is most preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group.
Examples of the halogen atom for the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include a group obtained by substituting part or all of hydrogen atoms in an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, with the above-described halogen atom.
The carbonyl group as the substituent is a group that is substituted for a methylene group (—CH2—) constituting the cyclic hydrocarbon group.
The cyclic hydrocarbon group as R101 may be a condensed cyclic group containing a condensed ring in which an aliphatic hydrocarbon ring is condensed with an aromatic ring. Examples of the condensed ring include a condensed ring in which one or more aromatic rings are condensed with a polycycloalkane having a bridged ring-based polycyclic skeleton. Specific examples of the bridged ring-based polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The condensed cyclic group is preferably a group containing a condensed ring in which two or three aromatic rings are condensed with a bicycloalkane and is more preferably a group containing a condensed ring in which two or three aromatic rings are condensed with bicyclo[2.2.2]octane. Specific examples of the condensed cyclic group as R101 include those represented by General Formulae (r-br-1) to (r-br-2). In the formulae, * represents a bonding site that is bonded to Y10 in General Formula (b-1).
Examples of the substituent which may be contained in the condensed cyclic group as R101 include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group.
Examples of the alkyl group, the alkoxy group, the halogen atom, and the halogenated alkyl group, as the substituent of the condensed cyclic group, include the same ones as those described as the substituent of the cyclic group as R101.
Examples of the aromatic hydrocarbon group as the substituent of the condensed cyclic group include a group (an aryl group; for example, a phenyl group or a naphthyl group) obtained by removing one hydrogen atom from an aromatic ring, a group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, 1-naphthylethyl group, or a 2-naphthylethyl group) obtained by substituting one hydrogen atom in the aromatic ring with an alkylene group, and heterocyclic groups each represented by General Formulae (r-hr-1) to (r-hr-6).
Examples of the alicyclic hydrocarbon group as the substituent of the condensed cyclic group include a group obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane or cyclohexane; a group obtained by removing one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; lactone-containing cyclic groups each represented by General Formulae (a2-r-1) to (a2-r-7); —SO2-containing cyclic groups each represented by General Formulae (a5-r-1) to (a5-r-4); and heterocyclic groups each represented by General Formulae (r-hr-7) to (r-hr-16).
Chain-like alkyl group which may have substituent:
The chain-like alkyl group as R101 may be linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15, and most preferably 3 to 10. Specific examples thereof include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.
Chain-like alkenyl group which may have substituent:
A chain-like alkenyl group as R101 may be linear or branched, and the chain-like alkenyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (an allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.
Among the above, the chain-like alkenyl group is preferably a linear alkenyl group, more preferably a vinyl group or a propenyl group, and particularly preferably a vinyl group.
Examples of the substituent in the chain-like alkyl group or alkenyl group as R101 include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and a cyclic group as R101.
Among the above, R101 is preferably a cyclic group which may have a substituent and more preferably a cyclic hydrocarbon group which may have a substituent. More specific examples thereof preferably include a phenyl group; a naphthyl group; a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by any one of General Formulae (a2-r-1) to (a2-r-7); and a —SO2-containing cyclic group represented by any one of General Formulae (a5-r-1) to (a5-r-4).
In General Formula (b-1), Y101 represents a single bond or a divalent linking group containing an oxygen atom.
In a case where Y101 represents a divalent linking group containing an oxygen atom, Y101 may contain an atom other than the oxygen atom. Examples of atoms other than the oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.
Examples of divalent linking groups containing an oxygen atom include non-hydrocarbon-based oxygen atom-containing linking groups such as an oxygen atom (an ether bond; —O—), an ester bond (—C(═O)—O—), an oxycarbonyl group (—O—C(═O)—), an amide bond (—C(═O)—NH—), a carbonyl group (—C(═O)—), or a carbonate bond (—O—C(═O)—O—); and combinations of the above-described non-hydrocarbon-based oxygen atom-containing linking groups with an alkylene group. Furthermore, a sulfonyl group (—SO2—) may be linked to the combination. Examples of such a divalent linking group containing an oxygen atom include linking groups each represented by General Formulae (y-a1-1) to (y-a1-7) shown below.
[In the formulae, V′101 represents a single bond or an alkylene group having 1 to carbon atoms, and V′102 represents a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]
The divalent saturated hydrocarbon group as V′102 is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and still more preferably an alkylene group having 1 to 5 carbon atoms.
The alkylene group as V′101 and V′102 may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferable.
Specific examples of the alkylene group as V′101 and V′102 include a methylene group [—CH2—]; an alkylmethylene group such as —CH(CH3)—, —CH(CH2CH3)—, —C(CH3)2—, —C(CH3)(CH2CH3)—, —C(CH3)(CH2CH2CH3)—, or —C(CH2CH3)2—; an ethylene group [—CH2CH2—]; an alkylethylene group such as —CH(CH3)CH2—, —CH(CH3)CH(CH3)—, —C(CH3)2CH2—, or —CH(CH2CH3)CH2—; a trimethylene group (n-propylene group) [—CH2CH2CH2—]; an alkyltrimethylene group such as —CH(CH3)CH2CH2— or —CH2CH(CH3)CH2—; a tetramethylene group [—CH2CH2CH2CH2—]; an alkyltetramethylene group such as —CH(CH3)CH2CH2CH2—, or —CH2CH(CH3)CH2CH2—; and a pentamethylene group [—CH2CH2CH2CH2CH2—].
Further, part of methylene groups in the alkylene group as V′101 and V′102 may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group in which one hydrogen atom has been removed from the cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group) as Ra′3 in General Formula (a1-r-1), and a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferable.
Y101 is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably any one of linking groups each represented by General Formulae (y-a1-1) to (y-a1-5).
In General Formula (b-1), V101 represents a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and the fluorinated alkylene group as V101 preferably have 1 to 4 carbon atoms. Examples of the fluorinated alkylene group as V101 include a group obtained by substituting part or all of hydrogen atoms in the alkylene group as V101 with a fluorine atom. Among them, V101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.
In General Formula (b-1), R102 represents a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms and more preferably a fluorine atom.
In a case where Y101 represents a single bond, specific examples of the anion moiety represented by General Formula (b-1) include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; and in a case where Y101 represents a divalent linking group containing an oxygen atom, specific examples thereof include an anion represented by any one of General Formulae (an-1) to (an-3) shown below.
[In the formula, R″101 represents an aliphatic cyclic group which may have a substituent, monovalent heterocyclic groups each represented by Chemical Formulae (r-hr-1) to (r-hr-6), a condensed cyclic group represented by General Formula (r-br-1) or (r-br-2), and a chain-like alkyl group which may have a substituent. R″102 is an aliphatic cyclic group which may have a substituent, a condensed cyclic group represented by General Formula (r-br-1) or (r-br-2), lactone-containing cyclic groups each represented by General Formulae (a2-r-1), (a2-r-3) to (a2-r-7), or —SO2-containing cyclic groups each represented by General Formulae (a5-r-1) to (a5-r-4). R″103 represents an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkenyl group which may have a substituent. V″101 represents a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. R102 represents a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Each v″ independently represents an integer in a range of 0 to 3, each q″ independently represents an integer in a range of 0 to 20, and n″ represents 0 or 1.]
The aliphatic cyclic group as R″101, R″102, and R″103 which may have a substituent is preferably the group exemplified as the cyclic aliphatic hydrocarbon group as R101 in General Formula (b-1). Examples of the substituent include the same one as the substituent which may be substituted for the cyclic aliphatic hydrocarbon group as R101 in General Formula (b-1).
The aromatic cyclic group which may have a substituent, as R″103, is preferably the group exemplified as the aromatic hydrocarbon group for the cyclic hydrocarbon group as R101 in General Formula (b-1). Examples of the substituent include the same one as the substituent which may be substituted for the aromatic hydrocarbon group as R101 in General Formula (b-1).
The chain-like alkyl group as R″101, which may have a substituent, is preferably the group exemplified as the chain-like alkyl group as R101 in General Formula (b-1). The chain-like alkenyl group as R″103, which may have a substituent, is preferably the group exemplified as the chain-like alkenyl group as R101 in General Formula (b-1).
Anion in component (b-2)
In General Formula (b-2), R104 and R105 each independently represent a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples of each of them include the same one as R101 in General Formula (b-1). However, R104 and R105 may be bonded to each other to form a ring.
R104 and R105 are preferably a chain-like alkyl group which may have a substituent and more preferably a linear or branched alkyl group or a linear or branched fluorinated alkyl group.
The chain-like alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. It is preferable that the number of carbon atoms in the chain-like alkyl group as R104 and R105 is small since the solubility in a resist solvent is also excellent in this range of the number of carbon atoms. Further, in the chain-like alkyl group as R104 and R105, it is preferable that the number of hydrogen atoms substituted with a fluorine atom is large since the acid strength increases and the transparency to high energy radiation of 250 nm or less or an electron beam is improved. The proportion of fluorine atoms in the chain-like alkyl group, that is, the fluorination rate is preferably in a range of 70% to 100% and more preferably in a range of 90% to 100%, and it is most preferable that the chain-like alkyl group is a perfluoroalkyl group in which all hydrogen atoms is substituted with a fluorine atom.
In General Formula (b-2), V102 and V103 each independently represent a single bond, an alkylene group, or a fluorinated alkylene group, and examples of each of them include the same one as V101 in General Formula (b-1).
in General Formula (b-2), L101 and L102 each independently represent a single bond or an oxygen atom.
Anion in component (b-3)
in General Formula (b-3), R106 to R108 each independently represent a cyclic group which may have a substituent, chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same one as R101 in General Formula (b-1).
In General Formula (b-3), L103 to L105 each independently represent a single bond, —CO—, or —SO2—.
Among the above, the anion moiety of the component (B) is preferably an anion of the component (b-1). Among these, an anion represented by any one of General Formulae (an-1) to (an-3) is more preferable, an anion represented by any one of General Formula (an-1) or (an-2) is still more preferable, and an anion represented by General Formula (an-2) is particularly preferable.
{Cation Moiety}
In General Formulae (b-1), (b-2), and (b-3), M′m+ represents an m-valent onium cation. Among them, a sulfonium cation and an iodonium cation are preferable. m represents an integer of 1 or more.
Examples of the preferred cation moiety ((M′m+)1/m) include the organic cations each represented by General Formulae (ca-1) to (ca-5) described above, and a cation represented by General Formula (ca-1) is preferable.
In the resist composition according to the present embodiment, the component (B) may be used alone or in a combination of two or more kinds thereof.
In a case where the resist composition contains the component (B), the content of the component (B) in the resist composition is preferably less than 50 parts by mass, more preferably in a range of 5 to 40 parts by mass, and still more preferably in a range of 10 to 30 parts by mass, with respect to 100 parts by mass of the component (A1).
In a case where the content of the component (B) is set to be in the preferred range described above, pattern formation can be satisfactorily carried out. Further, in a case where each component of the resist composition is dissolved in an organic solvent, the above range is preferable since a homogeneous solution is easily obtained and the storage stability of the resist composition is improved.
<<Base Component (D)>>
The resist composition according to the present embodiment may further contain a base component (a component (D)) other than the component (D0) that traps (that is, controls the acid diffusion) the acid generated upon exposure. The component (D) acts as a quencher (an acid diffusion controlling agent) which traps the acid generated in the resist composition upon exposure.
Examples of the component (D) include a photodecomposable base (D1) having an acid diffusion controllability (hereinafter, referred to as a “component (D1)”) which is lost by the decomposition upon exposure and a nitrogen-containing organic compound (D2) (hereinafter, referred to as a “component (D2)”) which does not correspond to the component (D1). Among these, the photodecomposable base (the component (D1)) is preferable since it is easy to enhance the characteristics of high sensitivity, roughness reduction, and suppression of the occurrence of coating defects.
In regard to component (D1)
In a case where a resist composition containing the component (D1) is obtained, the contrast between exposed portions and unexposed portions of the resist film can be further improved at the time of forming a resist pattern.
The component (D1) is not particularly limited as long as it decomposes upon exposure and loses the acid diffusion controllability. The component (D1) is preferably one or more compounds selected from the group consisting of a compound represented by General Formula (d1-1) (hereinafter, referred to as a “component (d1-1)”), a compound represented by General Formula (d1-2) (hereinafter, referred to as a “component (d1-2)”), and a compound represented by General Formula (d1-3) (hereinafter, referred to as a “component (d1-3)”).
In exposed portions of the resist film, the components (d1-1) to (d1-3) decompose and then lose the acid diffusion controllability (the basicity), and thus they cannot act as a quencher, while acting as a quencher in unexposed portions of the resist film.
[In the formulae, Rd1 to Rd4 represent cyclic groups which may have a substituent, chain-like alkyl groups which may have a substituent, or chain-like alkenyl groups which may have a substituent. However, the carbon atom adjacent to the S atom in Rd2 in General Formula (d1-2) has no fluorine atom bonded thereto. Yd1 represents a single bond or a divalent linking group. m represents an integer of 1 or more, and each Mm+ independently represents an m-valent organic cation].
{Component (d1-1)}
Anion Moiety
In General Formula (d1-1), Rd1 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same one as R′201 in each of General Formulae (ca-r-1) to (ca-r-7).
Among these, Rd1 is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Examples of the substituent which may be contained in these groups include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, lactone-containing cyclic groups each represented by any one of General Formulae (a2-r-1) to (a2-r-7), an ether bond, an ester bond, and a combination thereof. In a case where an ether bond or an ester bond is included as the substituent, the substituent may be bonded via an alkylene group, and the substituent in this case is preferably a linking group represented by any one of General Formulae (y-a1-1) to (y-a1-5).
Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure (a polycyclic structure consisting of a bicyclooctane skeleton and a ring structure other than the bicyclooctane skeleton).
The aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane.
The chain-like alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include a linear alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, or a decyl group, and a branched alkyl group such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, or a 4-methylpentyl group.
In a case where the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 4 carbon atoms. The fluorinated alkyl group may contain an atom other than the fluorine atom. Examples of the atom other than the fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom.
Preferred specific examples of the anion moiety of the component (d1-1) are shown below.
Cation Moiety
In General Formula (d1-1), Mm+ represents an m-valent organic cation.
The suitable examples of the organic cation as Mm+ include the same ones as the cations each represented by General Formulae (ca-1) to (ca-5), and the cation represented by General Formula (ca-1) is more preferable.
The component (d1-1) may be used alone, or a combination of two or more kinds thereof may be used.
{Component (d1-2)}
Anion Moiety
In General Formula (d1-2), Rd2 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same one as R′201 in each of General Formulae (ca-r-1) to (ca-r-7).
However, the carbon atom adjacent to the S atom in Rd2 has no fluorine atom bonded thereto (the carbon atom adjacent to the S atom in Rd2 is not substituted with a fluorine atom). As a result, the anion of the component (d1-2) becomes an appropriately weak acid anion, thereby improving the quenching ability of the component (D).
Rd2 is preferably a chain-like alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent. The chain-like alkyl group preferably has 1 to 10 carbon atoms and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group is more preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; and a group in which one or more hydrogen atoms have been removed from camphor or the like.
The hydrocarbon group as Rd2 may have a substituent. Examples of the substituent include the same one as the substituent which may be contained in the hydrocarbon group (the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-like alkyl group) as Rd1 in General Formula (d1-1).
Preferred specific examples of the anion moiety of the component (d1-2) are shown below.
Cation Moiety
In General Formula (d1-2), Mm represents an m-valent organic cation and is the same as Mm+ in General Formula (d1-1).
The component (d1-2) may be used alone, or a combination of two or more kinds thereof may be used.
{Component (d1-3)}
Anion Moiety
In General Formula (d1-3), Rd3 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same one as R′201 in each of General Formulae (ca-r-1) to (ca-r-7). A cyclic group containing a fluorine atom, a chain-like alkyl group, or a chain-like alkenyl group is preferable. Among the above, a fluorinated alkyl group is preferable, and the same one as the fluorinated alkyl group as Rd1 described above is more preferable.
In General Formula (d1-3), Rd4 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same one as R′ in each of General Formulae (ca-r-1) to (ca-r-7).
Among them, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an alkenyl group which may have a substituent, or a cyclic group which may have a substituent is preferable.
The alkyl group as Rd4 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Part of hydrogen atoms in the alkyl group as Rd4 may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group as Rd4 is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Among them, a methoxy group and an ethoxy group are preferable.
Examples of the alkenyl group as Rd4 include the same one as the alkenyl group as R′201, and a vinyl group, a propenyl group (an allyl group), a 1-methylpropenyl group, or a 2-methylpropenyl group is preferable. These groups may have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.
Examples of the cyclic group as Rd4 include the same one as the cyclic group described above as R′201, and the cyclic group is preferably an alicyclic group obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or an aromatic group such as a phenyl group or a naphthyl group. In a case where Rd4 represents an alicyclic group, the resist composition can be satisfactorily dissolved in an organic solvent, thereby improving lithography characteristics. In a case where Rd4 is an aromatic group, the resist composition is excellent in light absorption efficiency and thus has good sensitivity and lithography characteristics in the lithography using EUV or the like as a light source for exposure.
In General Formula (d1-3), Yd1 represents a single bond or a divalent linking group.
The divalent linking group as Yd1 is not particularly limited, and examples thereof include a divalent hydrocarbon group (an aliphatic hydrocarbon group or an aromatic hydrocarbon group) which may have a substituent and a divalent linking group containing a hetero atom. Examples of each of them include the same ones as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom, which are mentioned in the explanation of the divalent linking group as Ya01 in General Formula (a0-1).
Yd1 is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination of these. The alkylene group is more preferably a linear or branched alkylene group and still more preferably a methylene group or an ethylene group.
Preferred specific examples of the anion moiety for the component (d1-3) are shown below.
Cation Moiety
In General Formula (d1-3), Mm+ represents an m-valent organic cation and is the same as Mm+ in General Formula (d1-1).
One kind of the component (d1-3) may be used alone, or a combination of two or more kinds thereof may be used.
As the component (D1), any one of the above components (d1-1) to (d1-3) may be used alone, or a combination of two or more thereof may be used.
In a case where the resist composition contains the component (D1), the content of the component (D1) in the resist composition is preferably in a range of 0.5 to 20 parts by mass and more preferably in a range of 1 to 15 parts by mass with respect to 100 parts by mass of the component (A1).
In a case where the content of the component (D1) is equal to or larger than the preferred lower limit value, particularly excellent lithography characteristics and a particularly excellent resist pattern shape are easily obtained. On the other hand, in a case where the content of the component (D1) is equal to or smaller than the upper limit value, the sensitivity can be maintained satisfactorily and the throughput is also excellent.
Method of Producing Component (D1):
The methods of producing the components (d1-1) and (d1-2) are not particularly limited, and the components (d1-1) and (d1-2) can be produced by conventionally known methods.
Further, the method of producing the component (d1-3) is not particularly limited, and the component (d1-3) can be produced in the same manner as disclosed in United States Patent Application, Publication No. 2012-0149916.
In regard to component (D2)
The component (D) may contain a nitrogen-containing organic compound component (hereinafter, referred to as a “component (D2)”) which does not correspond to the above-described component (D1).
The component (D2) is not particularly limited as long as it acts as an acid diffusion controlling agent and does not correspond to the component (D1), and any conventionally known component may be used. Among the above, an aliphatic amine is preferable, among which a secondary aliphatic amine or a tertiary aliphatic amine is more preferable.
The aliphatic amine is preferably an amine having one or more aliphatic groups, where the aliphatic group has 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine obtained by substituting at least one hydrogen atom of ammonia (NH3) with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (an alkylamine or an alkyl alcohol amine) and a cyclic amine.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanol amine, triethanol amine, diisopropanol amine, triisopropanol amine, di-n-octanol amine, and tri-n-octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be a monocyclic compound (an aliphatic monocyclic amine), or a polycyclic compound (an aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.
Examples of other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine and triethanolamine triacetate, and triethanolamine triacetate is preferable.
In addition, as the component (D2), an aromatic amine may be used.
Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole, and derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, and N-tert-butoxycarbonylpyrrolidine.
The component (D2) may be used alone, or a combination of two or more kinds thereof may be used.
In a case where the resist composition contains the component (D2), the content of the component (D2) in the resist composition is typically in a range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A1). By setting the content within the above range, the resist pattern shape, the post-exposure temporal stability, and the like are improved.
<<At Least One Compound (E) Selected from Group Consisting of Organic Carboxylic Acid, Phosphorus Oxo Acid, and Derivatives Thereof>>
For the intended purpose of preventing any deterioration in sensitivity, and improving the resist pattern shape and the post-exposure temporal stability, the resist composition according to the present embodiment can contain at least one compound (E) (hereinafter referred to as a component (E)) selected from the group consisting of an organic carboxylic acid, and a phosphorus oxo acid and a derivative thereof, as an optional component.
The organic carboxylic acid suitably includes acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid.
Examples of the phosphorus oxo acid include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the phosphorus oxo acid derivative include an ester obtained by substituting a hydrogen atom in the above-described oxo acid with a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms and an aryl group having 6 to 15 carbon atoms.
Examples of the phosphoric acid derivative include a phosphoric acid ester such as di-n-butyl phosphate or diphenyl phosphate.
Examples of the phosphonic acid derivative include a phosphonic acid ester such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, or dibenzyl phosphonate.
Examples of the phosphinic acid derivative include a phosphinic acid ester and phenylphosphinic acid.
In the resist composition according to the present embodiment, the component (E) may be used alone or in a combination of two or more kinds thereof.
In a case where the resist composition contains the component (E), the content of the component (E) is typically in a range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A1).
<<Fluorine Additive Component (F)>>
The resist composition according to the present embodiment may further include a fluorine additive component (hereinafter, referred to as a “component (F)”) in order to impart water repellency to the resist film or to improve lithography characteristics.
As the component (F), a fluorine-containing polymeric compound described in Japanese Unexamined Patent Application, First Publication No. 2010-002870, Japanese Unexamined Patent Application, First Publication No. 2010-032994, Japanese Unexamined Patent Application, First Publication No. 2010-277043, Japanese Unexamined Patent Application, First Publication No. 2011-13569, and Japanese Unexamined Patent Application, First Publication No. 2011-128226 can be mentioned.
Specific examples of the component (F) include polymers having a constitutional unit (f1) represented by General Formula (f1-1) shown below. This polymer is preferably a polymer (homopolymer) consisting of only a constitutional unit (f1) represented by General Formula (f1-1) shown below; a copolymer of the constitutional unit (f1) and the constitutional unit (a1); and a copolymer of the constitutional unit (f1), a constitutional unit derived from acrylic acid or methacrylic acid, and the above-described constitutional unit (a1). The constitutional unit (a1) to be copolymerized with the constitutional unit (f1) is preferably a constitutional unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate or a constitutional unit derived from 1-methyl-1-adamantyl (meth)acrylate.
[In the formula, R has the same definition as described above. Rf102 and Rf103 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf102 and Rf103 may be the same or different from each other. nf1 represents an integer in a range of 0 to 5 and Rf101 represents an organic group containing a fluorine atom.]
In General Formula (f1-1), R bonded to the carbon atom at the α-position has the same definition as described above. R is preferably a hydrogen atom or a methyl group.
In General Formula (f1-1), the halogen atom as Rf102 and Rf103 is preferably a fluorine atom. Examples of the alkyl group having 1 to 5 carbon atoms as Rf102 and Rf103 include the same one as the alkyl group having 1 to 5 carbon atoms as R, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms as Rf102 and Rf103 include a group obtained by substituting part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms with a halogen atom. The halogen atom is preferably a fluorine atom. Among the above, Rf102 and Rf103 is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms and more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group.
In General Formula (f1-1), nf1 represents an integer in a range of 0 to 5, preferably an integer in a range of 0 to 3, and more preferably an integer of 1 or 2.
In General Formula (f1-1), Rf101 represents an organic group containing a fluorine atom and is preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms.
In addition, in the hydrocarbon group containing a fluorine atom, 25% or more of the hydrogen atoms in the hydrocarbon group are preferably fluorinated, more preferably 50% or more are fluorinated, and particularly preferably 60% or more are fluorinated since the hydrophobicity of the resist film during immersion exposure increases.
Among them, Rf101 is preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms and particularly preferably a trifluoromethyl group, —CH2—CF3, —CH2—CF2—CF3, or —CH(CF3)2, —CH2—CH2—CF3, or —CH2—CH2—CF2—CF2—CF2—CF3.
The weight average molecular weight (Mw) (based on the polystyrene-equivalent value determined by gel permeation chromatography) of the component (F) is preferably in a range of 1,000 to 50,000, more preferably in a range of 5,000 to 40,000, and most preferably in a range of 10,000 to 30,000. In a case where the weight average molecular weight is equal to or smaller than the upper limit value of this range, a resist solvent solubility sufficient to be used as a resist is exhibited. On the other hand, in a case where it is equal to or larger than the lower limit value of this range, the water repellency of the resist film is excellent.
Further, the polydispersity (Mw/Mn) of the component (F) is preferably in a range of 1.0 to 5.0, more preferably in a range of 1.0 to 3.0, and most preferably in a range of 1.0 to 2.5.
In the resist composition according to the present embodiment, the component (F) may be used alone or in a combination of two or more kinds thereof.
In a case where the resist composition contains the component (F), the content of the component (F) to be used is typically at a proportion of 0.5 to 10 parts by mass, with respect to 100 parts by mass of the component (A1).
<<Organic Solvent Component (S)>>
The resist composition according to the present embodiment may be produced by dissolving the resist materials in an organic solvent component (hereinafter, referred to as a “component (S)”).
The component (S) may be any organic solvent which can dissolve each of the components to be used to obtain a homogeneous solution, and any organic solvent can be suitably selected from those which are known in the related art as solvents for a chemically amplified resist composition and then used.
Examples of the component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols, such as ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate, polyhydric alcohol derivatives including compounds having an ether bond, such as a monoalkyl ether (such as monomethyl ether, monoethyl ether, monopropyl ether or monobutyl ether) or monophenyl ether of any of these polyhydric alcohols or compounds having an ester bond (among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferable); cyclic ethers such as dioxane; esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethylbenzyl ether, cresylmethyl ether, diphenyl ether, dibenzyl ether, phenetole, butylphenyl ether, ethyl benzene, diethyl benzene, pentyl benzene, isopropyl benzene, toluene, xylene, cymene and mesitylene; and dimethylsulfoxide (DMSO).
In the resist composition according to the present embodiment, the component (S) may be used alone or as a mixed solvent of two or more kinds thereof. Among these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferable.
Further, a mixed solvent obtained by mixing PGMEA with a polar solvent is also preferable as the component (S). The blending ratio (mass ratio) of the mixed solvent can be appropriately determined, taking into consideration the compatibility of the PGMEA with the polar solvent; however, it is preferably in a range of 1:9 to 9:1 and more preferably in a range of 2:8 to 8:2.
More specifically, in a case where EL or cyclohexanone is blended as the polar solvent, the PGMEA:EL or cyclohexanone mass ratio is preferably in a range of 1:9 to 9:1 and more preferably in a range of 2:8 to 8:2. Alternatively, in a case where PGME is blended as the polar solvent, the PGMEA:PGME mass ratio is preferably in a range of 1:9 to 9:1, more preferably in a range of 2:8 to 8:2, and still more preferably in a range of 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferable.
Further, the component (S) is also preferably a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone. In this case, as the mixing ratio, the mass ratio of the former to the latter is preferably in a range of 70:30 to 95:5. The amount of the component (S) to be used is not particularly limited and is suitably set, depending on a thickness of a film to be coated, to a concentration at which the component (S) can be applied onto a substrate or the like. Generally, the component (S) is used such that the solid content concentration of the resist composition is in a range of 0.1% to 20% by mass and preferably in a range of 0.2% to 15% by mass.
As desired, other miscible additives can also be added to the resist composition according to the present embodiment. For example, for improving the performance of the resist film, an additive resin, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, a halation prevention agent, and a dye can be appropriately contained therein.
After dissolving the resist material in the component (S), the resist composition according to the present embodiment may be subjected to removal of impurities and the like by using a porous polyimide membrane, a porous polyamideimide membrane, or the like. For example, the resist composition may be filtered using a filter made of a porous polyimide membrane, a filter made of a porous polyamideimide membrane, or a filter made of a porous polyimide membrane and a porous polyamideimide membrane. Examples of the porous polyimide membrane and the porous polyamideimide membrane include those described in Japanese Unexamined Patent Application, First Publication No. 2016-155121.
The resist composition according to the present embodiment described above has the resin component (A1) having the constitutional unit (a0) represented by General Formula (a0-1) and the photodecomposable base (D0) in which the acid dissociation constant (pKa) of the conjugate acid is 4.0 or less.
The constitutional unit (a0) has Ar (a benzene ring or a naphthalene ring) in which a hydroxy group is bonded to the terminal of the side chain, that is, a phenolic hydroxyl group (an aromatic ring having a hydroxy group) that acts as a proton source. In addition, in the constitutional unit (a0), the bond between the oxygen atom (—O—) of the carbonyloxy group (—C(═O)—O—) in General Formula (a0-1) and the secondary carbon bonded to the above oxygen atom are cleaved under action of acid, whereby a carbocation is generated. In the constitutional unit (a0), the hydroxy group bonded to Ar (a benzene ring or a naphthalene ring) donates an electron to Ar. As a result, the electrical unevenness of the positive charge of the generated carbocation is further suppressed, and thus the generated carbocation is more stabilized. As a result, in the constitutional unit (a0), the deprotection reaction proceeds appropriately upon exposure.
On the other hand, in the photodecomposable base (D0), the acid dissociation constant (pKa) of the conjugate acid (a compound in which one hydrogen ion is added to the anion moiety) is 4.0 or less. In exposed portions of the resist film, the component (D0) decomposes and then loses the acid diffusion controllability (the basicity), and thus it cannot act as a quencher, while acting as a quencher in unexposed portions of the resist film, thereby capable of suitably suppressing the diffusion of the acid generated upon exposure. This makes it possible to more improve the pattern shape.
According to the resist composition according to the present embodiment, it is possible to improve all of the sensitivity, the resolution, the roughness reducing property, and the rectangularity of the pattern shape, due to the synergistic effect of the combination of these resin component (A1) having the constitutional unit (a0) and photodecomposable base (D0) in which the pKa of the conjugate acid is 4.0 or less.
The method of forming a resist pattern according to the second aspect of the present invention is a method that includes a step of forming a resist film on a support using the resist composition of the above-described embodiment, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern.
Examples of one embodiment of such a method of forming a resist pattern include a method of forming a resist pattern carried out as described below.
First, the resist composition of the above-described embodiment is applied onto a support with a spinner or the like, and a baking (post-apply baking (PAB)) treatment is carried out, for example, at a temperature condition of 80° C. to 150° C. for 40 to 120 seconds, preferably for 60 to 90 seconds to form a resist film.
Following the selective exposure carried out on the resist film by, for example, exposure through a mask (mask pattern) having a predetermined pattern formed thereon by using an exposure apparatus such as an electron beam lithography apparatus or an EUV exposure apparatus, or direct irradiation of the resist film for drawing with an electron beam without using a mask pattern, baking treatment (post-exposure baking (PEB)) is carried out, for example, under a temperature condition in a range of 80° C. to 150° C. for 40 to 120 seconds and preferably 60 to 90 seconds.
Next, the resist film is subjected to a developing treatment. The developing treatment is carried out using an alkali developing solution in a case of an alkali developing process, and a developing solution containing an organic solvent (organic developing solution) in a case of a solvent developing process.
After the developing treatment, it is preferable to carry out a rinse treatment. As the rinse treatment, water rinsing using pure water is preferable in a case of an alkali developing process, and rinsing using a rinse liquid containing an organic solvent is preferable in a case of a solvent developing process.
In a case of a solvent developing process, after the developing treatment or the rinse treatment, the developing solution or the rinse liquid remaining on the pattern can be removed by a treatment using a supercritical fluid.
After the developing treatment or the rinse treatment, drying is carried out. As desired, baking treatment (post-baking) can be carried out following the developing treatment.
In this manner, a resist pattern can be formed.
The support is not particularly limited, and a known one in the related art can be used. For example, a substrate for an electronic component, and such a substrate having a predetermined wiring pattern formed thereon can be used. Specific examples of the material of the substrate include metals such as silicon wafer, copper, chromium, iron and aluminum; and glass. Suitable materials for the wiring pattern include copper, aluminum, nickel, and gold.
Further, as the support, any support having the substrate described above, on which an inorganic and/or organic film is provided, may be used. Examples of the inorganic film include an inorganic antireflection film (an inorganic BARC). Examples of the organic film include an organic antireflection film (an organic BARC) and an organic film such as a lower-layer organic film used in a multilayer resist method.
Here, the multilayer resist method is a method in which at least one layer of an organic film (lower-layer organic film) and at least one layer of a resist film (upper-layer resist film) are provided on a substrate, and a resist pattern formed on the upper-layer resist film is used as a mask to carry out patterning of the lower-layer organic film. This method is considered as a method capable of forming a pattern having a high aspect ratio. More specifically, in the multilayer resist method, a desired thickness can be ensured by the lower-layer organic film, and as a result, the thickness of the resist film can be reduced, and an extremely fine pattern with a high aspect ratio can be formed.
The multilayer resist method is classified into a method in which a double-layer structure consisting of an upper-layer resist film and a lower-layer organic film is formed (double-layer resist method), and a method in which a multilayer structure having three or more layers consisting of an upper-layer resist film, a lower-layer organic film and one or more intermediate layers (thin metal films or the like) provided between the upper-layer resist film and the lower-layer organic film (triple-layer resist method).
The wavelength to be used for exposure is not particularly limited and the exposure can be carried out using radiation such as an ArF excimer laser, a KrF excimer laser, an F2 excimer laser, an extreme ultraviolet ray (EUV), a vacuum ultraviolet ray (VUV), an electron beam (EB), an X-ray, or a soft X-ray. The resist composition is highly useful for a KrF excimer laser, an ArF excimer laser, EB, or EUV, more useful for an ArF excimer laser, EB or EUV, and particularly useful for EB or EUV. That is, the method of forming a resist pattern according to the present embodiment is a method particularly useful in a case where the step of exposing the resist film includes an operation of exposing the resist film to an extreme ultraviolet ray (EUV) or an electron beam (EB).
The exposure of the resist film can be a general exposure (dry exposure) carried out in air or an inert gas such as nitrogen, or liquid immersion exposure (liquid immersion lithography).
The liquid immersion lithography is an exposure method in which the region between the resist film and the lens at the lowermost position of the exposure apparatus is pre-filled with a solvent (liquid immersion medium) that has a larger refractive index than the refractive index of air, and the exposure (immersion exposure) is carried out in this state.
The liquid immersion medium is preferably a solvent that exhibits a refractive index larger than the refractive index of air but smaller than the refractive index of the resist film to be exposed. The refractive index of such a solvent is not particularly limited as long as it satisfies the above-described requirements.
Examples of the solvent which exhibits a refractive index that is larger than the refractive index of air but smaller than the refractive index of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents.
Specific examples of the fluorine-based inert liquids include liquids containing a fluorine-based compound such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, or C5H3F7 as the main component, and the boiling point is preferably in a range of 70° C. to 180° C. and more preferably in a range of 80° C. to 160° C. A fluorine-based inert liquid having a boiling point in the above-described range is advantageous in that removing the medium used in the liquid immersion after the exposure can be carried out by a simple method.
A fluorine-based inert liquid is particularly preferably a perfluoroalkyl compound obtained by substituting all hydrogen atoms of the alkyl group with a fluorine atom. Examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
Further, specific examples of the perfluoroalkyl ether compound include perfluoro(2-butyl-tetrahydrofuran) (boiling point: 102° C.), and examples of the perfluoroalkylamine compound include perfluorotributylamine (boiling point: 174° C.).
As the liquid immersion medium, water is preferable in terms of cost, safety, environment, and versatility.
Examples of the alkali developing solution used for a developing treatment in an alkali developing process include an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH).
The organic solvent contained in the organic developing solution, which is used for a developing treatment in a solvent developing process may be any organic solvent capable of dissolving the component (A) (component (A) prior to exposure), and can be appropriately selected from the conventionally known organic solvents. Specific examples of the organic solvent include polar solvents such as a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, a nitrile-based solvent, an amide-based solvent, and an ether-based solvent, and hydrocarbon-based solvents.
A ketone-based solvent is an organic solvent containing C—C(═O)—C in the structure thereof. An ester-based solvent is an organic solvent containing C—C(═O)—O—C in the structure thereof. An alcohol-based solvent is an organic solvent containing an alcoholic hydroxyl group in the structure thereof. An “alcoholic hydroxyl group” indicates a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. A nitrile-based solvent is an organic solvent containing a nitrile group in the structure thereof. An amide-based solvent is an organic solvent containing an amide group in the structure thereof. An ether-based solvent is an organic solvent containing C—O—C in the structure thereof.
Some organic solvents have a plurality of the functional groups which characterize the above-described solvents in the structure thereof. In such a case, the organic solvent can be classified as any type of solvent having a characteristic functional group. For example, diethylene glycol monomethyl ether can be classified as an alcohol-based solvent or an ether-based solvent.
A hydrocarbon-based solvent consists of a hydrocarbon which may be halogenated and does not have any substituent other than the halogen atom. The halogen atom is preferably a fluorine atom.
Among the above, the organic solvent contained in the organic developing solution is preferably a polar solvent and more preferably a ketone-based solvent, an ester-based solvent, or a nitrile-based solvent.
Examples of the ketone-based solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylenecarbonate, γ-butyrolactone and methylamyl ketone (2-heptanone). Among these examples, the ketone-based solvent is preferably methylamyl ketone (2-heptanone).
Examples of the ester-based solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate. Among these, the ester-based solvent is preferably butyl acetate.
Examples of the nitrile-based solvent include acetonitrile, propionitrile, valeronitrile, and butyronitrile.
As desired, the organic developing solution may have a conventionally known additive blended. Examples of the additive include surfactants. The surfactant is not particularly limited, and for example, an ionic or non-ionic fluorine-based and/or a silicon-based surfactant can be used. The surfactant is preferably a non-ionic surfactant and more preferably a non-ionic fluorine surfactant or a non-ionic silicon-based surfactant.
In a case where a surfactant is blended, the amount of the surfactant to be blended is typically in a range of 0.001% to 5% by mass, preferably in a range of 0.005% to 2% by mass, and more preferably in a range of 0.01% to 0.5% by mass with respect to the total amount of the organic developing solution.
The developing treatment can be carried out by a conventionally known developing method. Examples thereof include a method in which the support is immersed in the developing solution for a predetermined time (a dip method), a method in which the developing solution is cast upon the surface of the support by surface tension and maintained for a predetermined time (a puddle method), a method in which the developing solution is sprayed onto the surface of the support (spray method), and a method in which a developing solution is continuously ejected from a developing solution ejecting nozzle and applied onto a support which is scanned at a constant rate while being rotated at a constant rate (dynamic dispense method).
As the organic solvent contained in the rinse liquid used in the rinse treatment after the developing treatment in a case of a solvent developing process, an organic solvent hardly dissolving the resist pattern can be appropriately selected and used, among the organic solvents mentioned as organic solvents that are used for the organic developing solution. In general, at least one kind of solvent selected from the group consisting of a hydrocarbon-based solvent, a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, an amide-based solvent, and an ether-based solvent is used. Among these, at least one kind of solvent selected from the group consisting of a hydrocarbon-based solvent, a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, and an amide-based solvent is preferable, at least one kind of solvent selected from the group consisting of an alcohol-based solvent and an ester-based solvent is more preferable, and an alcohol-based solvent is particularly preferable.
The alcohol-based solvent used for the rinse liquid is preferably a monohydric alcohol of 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched, or cyclic. Specific examples thereof include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol and 2-hexanol are more preferable.
As the organic solvent, one kind of solvent may be used alone, or two or more kinds of solvents may be used in combination. Further, an organic solvent other than the above-described examples or water may be mixed thereto. However, in consideration of the development characteristics, the amount of water to be blended in the rinse liquid is preferably 30% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and particularly preferably 3% by mass or less with respect to the total amount of the rinse liquid.
A conventionally known additive can be blended with the rinse liquid as necessary. Examples of the additive include surfactants. Examples of the surfactant include the same ones as those described above, the surfactant is preferably a non-ionic surfactant and more preferably a non-ionic fluorine surfactant or a non-ionic silicon-based surfactant.
In a case where a surfactant is blended, the amount of the surfactant to be blended is typically in a range of 0.001% to 5% by mass, preferably in a range of 0.005% to 2% by mass, and more preferably in a range of 0.01% to 0.5% by mass with respect to the total amount of the rinse liquid.
The rinse treatment (the washing treatment) using a rinse liquid can be carried out by a conventionally known rinse method. Examples of the rinse treatment method include a method (a rotational coating method) in which the rinse liquid is continuously ejected to the support while rotating it at a constant rate, a method (dip method) in which the support is immersed in the rinse liquid for a predetermined time, and a method (spray method) in which the rinse liquid is sprayed onto the surface of the support.
According to the method of forming a resist pattern according to the present embodiment described above, since the resist composition according to the embodiment described above is used, it is possible to form a resist pattern that has good sensitivity, good resolution, good roughness reducing property, and high rectangularity.
Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.
<Preparation of Resist Composition>
Each of the components shown in Tables 1 and 2 was mixed and dissolved to prepare a resist composition of each Example.
In Tables 1 and 2, each abbreviation has the following meaning. The numerical values in the brackets are blending amounts (parts by mass).
(A)-1: A polymeric compound represented by Chemical Formula (A1-1). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 7,000, and the polydispersity (Mw/Mn) is 1.66. The polymerization compositional ratio (the ratio (the molar ratio) of the constitutional unit in the structural formula) is 1=100.
(A)-2: A polymeric compound represented by Chemical Formula (A1-2). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 6,600, and the polydispersity (Mw/Mn) is 1.62. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-3: A polymeric compound represented by Chemical Formula (A1-3). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 7,200, and the polydispersity (Mw/Mn) is 1.71. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-4: A polymeric compound represented by Chemical Formula (A1-4). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 6,700, and the polydispersity (Mw/Mn) is 1.66. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-5: A polymeric compound represented by Chemical Formula (A1-5). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 6,800, and the polydispersity (Mw/Mn) is 1.70. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-6: A polymeric compound represented by Chemical Formula (A1-6). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 6,700, and the polydispersity (Mw/Mn) is 1.71. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-7: A polymeric compound represented by Chemical Formula (A1-7). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 6,600, and the polydispersity (Mw/Mn) is 1.65. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-8: A polymeric compound represented by Chemical Formula (A1-8). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 7,000, and the polydispersity (Mw/Mn) is 1.67. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-9: A polymeric compound represented by Chemical Formula (A1-9). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 6,900, and the polydispersity (Mw/Mn) is 1.67. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-10: A polymeric compound represented by Chemical Formula (A1-10). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 7,000, and the polydispersity (Mw/Mn) is 1.66. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-11: A polymeric compound represented by Chemical Formula (A1-11). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 6,600, and the polydispersity (Mw/Mn) is 1.68. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-12: A polymeric compound represented by Chemical Formula (A1-12). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 7,000, and the polydispersity (Mw/Mn) is 1.70. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(A)-13: A polymeric compound represented by Chemical Formula (A1-13). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 6,800, and the polydispersity (Mw/Mn) is 1.71. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m/n=20/30/50.
(A)-14: A polymeric compound represented by Chemical Formula (A2-1). The weight average molecular weight (Mw) in terms of polystyrene equivalent value, acquired by the GPC measurement, is 6,600, and the polydispersity (Mw/Mn) is 1.66. The copolymerization composition ratio (the ratio (the molar ratio) among constitutional units in the structural formula) determined by 13C-NMR is 1/m=50/50.
(B)-1: an acid generator consisting of a compound represented by Chemical Formula (B1-1).
(D)-1: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-1). The acid dissociation constant (pKa) of the conjugate acid is 1.3.
(D)-2: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-2). The acid dissociation constant (pKa) of the conjugate acid is 3.0.
(D)-3: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-3). The acid dissociation constant (pKa) of the conjugate acid is 3.3.
(D)-4: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-4). The acid dissociation constant (pKa) of the conjugate acid is 3.0.
(D)-5: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-5). The acid dissociation constant (pKa) of the conjugate acid is 3.0.
(D)-6: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-6). The acid dissociation constant (pKa) of the conjugate acid is 1.3.
(D)-7: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-7). The acid dissociation constant (pKa) of the conjugate acid is 1.3.
(D)-8: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-8). The acid dissociation constant (pKa) of the conjugate acid is 1.3.
(D)-9: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-9). The acid dissociation constant (pKa) of the conjugate acid is 1.3.
(D)-10: A photodecomposable base consisting of a compound represented by Chemical Formula (D0-10). The acid dissociation constant (pKa) of the conjugate acid is 3.0.
(D)-11: A photodecomposable base consisting of a compound represented by Chemical Formula (D1-1). The acid dissociation constant (pKa) of the conjugate acid is 4.2.
Regarding the above (D)-1 to (D)-11, the acid dissociation constant (pKa) of the conjugate acid was calculated from the simulation using “ACD/Labs” (product name, manufactured by Advanced Chemistry Development Inc.).
(S)-1: A mixed solvent of propylene glycol monomethyl ether acetate/propylene glycol monomethyl ether=60/40 (mass ratio)
<Formation of Resist Pattern>
The resist composition of each Example was applied onto an 8-inch silicon substrate which had been subjected to a hexamethyldisilazane (HMDS) treatment using a spinner, the coated wafer was subjected to a post-apply baking (PAB) treatment on a hot plate at a temperature of 110° C. for 60 seconds so that the coated wafer was dried to form a resist film having a film thickness of 30 nm.
Next, drawing (exposure) was carried out on the resist film by using an electron beam lithography apparatus JEOL-JBX-9300FS (manufactured by JEOL Ltd.), with the target size being set to a 1:1 line and space pattern (hereinafter, written as an “LS pattern”) of a line width of 50 nm, at an acceleration voltage of 100 kV. Thereafter, a post-exposure baking (PEB) treatment was carried out on the resist film at 90° C. for 60 seconds.
Subsequently, alkali development was carried out at 23° C. for 60 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (product name, manufactured by TOKYO OHKA KOGYO CO., LTD.).
Thereafter, rinsing was carried out with pure water for 15 seconds.
As a result of the above, a 1:1 LS pattern having a line width of 50 nm was formed.
[Evaluation of Optimum Exposure Amount (Eop)]
According to <Formation of resist pattern> described above, an optimum exposure amount Eop (μC/cm2) for forming the LS pattern having the target size was determined. The results are shown in Tables 3 to 4 as “Eop (μC/cm2)”.
[Evaluation of Linewise Roughness (LWR)]
3σ of the LS pattern formed in <Formation of resist pattern> described above, which is a scale indicating LWR, was determined. The results are shown in Tables 3 to 4 as “LWR (nm)”.
“3σ” indicates a triple value (unit: nm) of the standard deviation (a) determined from measurement results obtained by measuring 400 line positions in the longitudinal direction of the line with a scanning electron microscope (acceleration voltage: 800V, product name: S-9380, manufactured by Hitachi High-Tech Corporation).
The smaller the value of 3a is, the smaller the roughness in the line side wall is, which means an LS pattern having a more uniform width was obtained.
[Evaluation of Resolution]
LS patterns were formed by gradually increasing the exposure amount from the optimum exposure amount Eop described above, and the limiting resolution at the above Eop, specifically, the minimum size of the pattern that was resolved without being collapsed were determined using a scanning electron microscope S-9380 (manufactured by Hitachi High-Tech Corporation). The results are shown in Tables 3 to 4 as “Limiting resolution (nm)”.
[Evaluation of Pattern Shape]
The cross-sectional shape of each of the obtained LS patterns in <Formation of resist pattern> described above was observed using a scanning electron microscope (acceleration voltage: 800V, product name: SU-8000, manufactured by Hitachi High-Tech Corporation). This shape was evaluated according to the following evaluation criteria. The obtained results are shown in Tables 3 to 4 as “Pattern shape”.
A: The cross-sectional shape of the pattern is rectangular and has high verticality.
B: The verticality of the cross-sectional shape of the pattern is slightly inferior to that of A.
C: The cross-sectional shape of the pattern is top rounded (the top of the pattern is round) or T-top shaped.
As shown in Tables 3 and 4, it has been confirmed that it is possible to form a resist pattern that has good sensitivity, good resolution, good roughness reducing property, and high rectangularity with the resist compositions of Examples 1 to 22 to which the present invention has been applied, as compared with the resist compositions of Comparative Examples 1 and 2.
While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the invention. Accordingly, the invention is not to be considered as being limited by the foregoing description and is only limited by the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-204407 | Dec 2020 | JP | national |
