Patent Application
20240427244
The present invention relates to a resist composition and a method for forming a resist pattern.
Priority is claimed on Japanese Patent Application No. 2021-180983, filed on Nov. 5, 2021, 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 rapid progress in the field of pattern fining. Typically, these 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 chemical amplification-type 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 resist pattern formation, the behavior of an 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 chemical amplification-type 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 that contains an acid generator having a specific anion moiety (a sulfonate anion) and an acid generator having a specific cation moiety different from the acid generator. According to the disclosed resist composition, a resist pattern having a good shape can be formed.
With further advances in lithography techniques, rapid progress in the field of pattern fining is being achieved together with the expansion of application fields. In association with this, in a case of manufacturing a semiconductor element or the like, a technique that makes it possible to form a fine pattern in a good shape is required.
However, with respect to such requirements, both sensitivity, roughness reduction property, and pattern shape are not always achieved sufficiently in resist pattern formation with the resist composition in the related art, which is described in Patent Document 1, and thus they need to be achieved at a higher level.
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 which achieves higher sensitivity and makes it possible to form a resist pattern having a good roughness reduction property and a good pattern shape, and a method for forming a resist pattern by using the resist composition.
In order to achieve the aforementioned object, the inventors of the present invention carried out intensive research focusing on the acid generator and the acid diffusion-controlling agent. As a result, the inventors of the present invention found that the above object can be achieved by using in combination an acid generator having a specific molar absorption coefficient and an acid diffusion-controlling agent having a specific anion moiety, whereby the present invention was completed. More specifically, the present invention employs the following aspects.
A 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, the resist composition containing a base material component (A) that exhibits changed solubility in a developing solution under action of acid, an acid generator component (B) that generates acid upon exposure; and an acid diffusion-controlling agent (D) that controls diffusion of the acid generated from the acid generator component (B), where the acid generator component (B) includes a compound (B0) having a molar absorption coefficient of 50,000 mol−1·L·cm−1 or less at an exposure wavelength of 193 nm, and the acid diffusion-controlling agent (D) includes a compound (D0) represented by General Formula (d0).
Rd01-Yd01-CH2—SO3⊖(Mm⊕)1/m (d0)
[In the formula, Rd01 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. Yd01 represents a divalent linking group containing an oxygen atom. m represents an integer of 1 or more, and Mm+ represents an m-valent organic cation.]
The second aspect according to the present invention is a method for 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 which achieves higher sensitivity and makes it possible to form a resist pattern having a good roughness reduction property and a good pattern shape, and a method for forming a resist pattern by using the resist composition.
In the present specification and the scope of the present claims, the term “aliphatic” is a relative concept used with respect to the term “aromatic” and defines a group or compound that has no aromaticity.
The term “alkyl group” includes a monovalent saturated hydrocarbon group that is linear, branched, or cyclic unless otherwise specified. The same applies to the alkyl group of an alkoxy group.
The term “alkylene group” includes a divalent saturated hydrocarbon group that is linear, branched, or cyclic unless otherwise specified.
Examples of the “halogen atom” include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The term “constitutional unit” means a monomer unit (a monomeric unit) that contributes to the formation of a polymeric compound (a resin, a polymer, or a copolymer).
The expression “may have a substituent” includes both 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.
The term “exposure” is used as a general concept that includes irradiation with any form of radiation.
The term “acid-decomposable group” is a group having acid decomposability, in which at least some of the 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 that are decomposed 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).
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.
The term “acid-dissociable group” refers to any one of (i) a group having acid dissociability, 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 some of the 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 be 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, thereby increasing the polarity. As a result of the above, the polarity of the total component (A1) is increased. With 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.
The term “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 generally 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 generally 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 weight-average molecular weight in terms of the polystyrene equivalent value determined by gel permeation chromatography (GPC) is used.
The term “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 (Rαx) that is substituted for a hydrogen atom bonded to the carbon atom at the α-position is an atom other than the hydrogen atom or a group. In addition, the acrylic acid ester includes itaconic acid diester in which the substituent (Rαx) has been substituted with a substituent having an ester bond and α-hydroxyacryl ester in which the substituent (Rαx) has been substituted with a hydroxyalkyl group or a group obtained by modifying a hydroxyl group thereof. 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, acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent is also referred to as an α-substituted acrylic acid ester.
The term “derivative” includes a compound in which the hydrogen atom at the α-position of the object compound has been substituted with another substituent such as an alkyl group or a halogenated alkyl group; and derivatives thereof. Examples of the derivatives thereof include a derivative in which the hydrogen atom of the hydroxyl group of the object compound in which the hydrogen atom at the α-position may be substituted with a substituent is substituted with an organic group; and a derivative in which a substituent other than a hydroxyl group is bonded to the object compound in which the hydrogen atom at the α-position may be substituted with a substituent. It should be noted that 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 a hydrogen atom at the α-position of hydroxystyrene include the same as those for Rαx.
In the present specification and the present claims, asymmetric carbons may be present and enantiomers or diastereomers may be present depending on the structures of the chemical formulae. In that case, these isomers are represented by one chemical formula. These isomers may be used alone or in the form of a mixture.
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, an acid generator component (B) (hereinafter, also referred to as a “component (B)” that generates acid upon exposure, and an acid diffusion-controlling agent (D) (hereinafter, also referred to as a “component (D)”) that controls the diffusion of the acid generated from the component (B).
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, acid is generated from the component (B) 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, thereby generating the difference in solubility in the developing solution between exposed portions and unexposed portions of the resist film. Therefore, by subjecting the resist film to development, exposed portions of the resist film are dissolved and removed to form a positive-tone resist pattern in a case where the resist composition is a positive-tone type, whereas unexposed portions of the resist film are dissolved and removed to form a negative-tone resist pattern in a case where the resist composition is a negative-tone type.
In the present specification, a resist composition which forms a positive-tone resist pattern by dissolving and removing exposed portions of the resist film is called a positive-tone resist composition, and a resist composition which forms a negative-tone resist pattern by dissolving and removing unexposed portions of the resist film is called a negative-tone resist composition. The resist composition according to the present embodiment may be a positive-tone resist composition or a negative-tone resist composition. In addition, in the resist pattern formation, 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 a developing solution containing an organic solvent (organic developing solution) in the developing treatment.
In the resist composition according to the present embodiment, the component (A) preferably 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. In the alkali developing process and the solvent developing process, since the polarity of the base material component before and after the exposure is changed by using the component (A1), an excellent development contrast can be obtained.
As the component (A), another polymeric compound and/or a 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 the resist composition according to the present embodiment, the component (A) may be “base material component which generates an acid upon light exposure and whose solubility in a developing solution is changed due to an action of the acid”. In a case where the component (A) is a base material component which generates an acid upon light exposure and whose solubility in a developing solution is changed due to an action of an acid, it is preferable that a component (A1) described below be a resin which generates an acid upon light exposure and whose solubility in a developing solution is changed due to an action of an acid. As such a resin, a polymeric compound having a constitutional unit that generates acid upon exposure can be used. As the constitutional unit that generates acid upon exposure, a known constitutional unit can be used.
The component (A1) is a resin component that exhibits changed solubility in a developing solution under action of acid.
The component (A1) preferably has a constitutional unit (a1) that includes an acid-decomposable group having a polarity that is increased under action of acid.
The component (A1) may have other constitutional units as necessary in addition to the constitutional unit (a1).
<<Constitutional Unit (a1)>>
The constitutional unit (a1) is a constitutional unit that contains an acid-decomposable group having a polarity that is increased under action of acid.
Examples of the acid-dissociable group include those which have been proposed so far as acid-dissociable groups for the base resin for a chemical amplification-type resist composition.
Specific examples of the acid-dissociable group of the base resin proposed for a chemical amplification-type resist composition include an “acetal-type acid-dissociable group”, a “tertiary alkyl ester-type acid-dissociable group”, and a “tertiary alkyloxycarbonyl acid-dissociable group” described below.
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 of Ra′1 and Ra′2 to form a ring.]
In General Formula (a1-r-1), it is preferable that at least one of Ra′1 or Ra′2 represent 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, examples of the alkyl group include the same alkyl groups described as the examples of the substituent which may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester. Among these, an alkyl group having 1 to 5 carbon atoms is preferable. 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 preferably has 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 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. Among these, 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 preferably has 3 to 6 carbon atoms, and specific examples thereof 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 the aromatic ring may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably has 5 to 20 carbon atoms, still more preferably has 6 to 15 carbon atoms, and particularly preferably has 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 some of the 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 in which one hydrogen atom has been removed from the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring (such as an aryl group or a heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound having two or more aromatic rings (such as biphenyl or fluorene); and a group in which one hydrogen atom of the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring has been substituted with an alkylene group (for example, 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 has 1 or 2 carbon atoms, and particularly preferably has 1 carbon atom.
The cyclic hydrocarbon group as Ra′3 may include 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 will also be collectively referred to as “Rax5”).
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 chain-like divalent 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. Here, some or all hydrogen atoms in the chain-like saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group, and the aromatic hydrocarbon group as RP1 and RP2 may be substituted with fluorine atoms. 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 a group obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.
In a case where Ra′3 is bonded to any of Ra′1 and Ra′2 to form a ring, the cyclic group is preferably a 4- to 7-membered ring and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl 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 represents 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 (an aliphatic hydrocarbon group which is a monocyclic group, an aliphatic hydrocarbon group which is a polycyclic group, or an aromatic hydrocarbon group) as Ra′4 include the same groups as those for Ra′3.
As the chain-like or cyclic alkenyl group as Ra′4, an alkenyl group having 2 to 10 carbon atoms is preferable.
Examples of the hydrocarbon group as Ra′5 or Ra′6 include the same groups as those for Ra′3.
In a case where Ra′5 and Ra′6 are bonded to each other to form a ring, suitable examples thereof include a group represented by General Formula (a1-r2-1), a group represented by General Formula (a1-r2-2), and a group represented by General Formula (a1-r2-3).
Meanwhile, in a case where Ra′4 to Ra′6 independently represent a hydrocarbon group without being bonded to each other, suitable examples thereof include a group represented by General Formula (a1-r2-4).
[In General Formula (a1-r2-1), Ra′10 represents a linear or branched alkyl group having 1 to 12 carbon atoms, in which a part thereof may be substituted with a halogen atom or a hetero atom-containing group. Ra′11 represents a group that forms an aliphatic cyclic group together with the carbon atom to which Ra′10 has been bonded. In General Formula (a1-r2-2), Ya represents a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms contained in the cyclic hydrocarbon group may be substituted. Ra101 to Ra103 each independently represents 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. Some or all of the hydrogen atoms contained in the chain-like saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra101 to Ra103 may be bonded to 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. Ra104 represents an aromatic hydrocarbon group which may have a substituent. In General Formula (a1-r2-4), Ra′12 and Ra′13 each independently represents a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the 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 General Formula (a1-r2-1), Ra′10 represents a linear or branched alkyl group having 1 to 12 carbon atoms, in which a part thereof may be substituted with a halogen atom or a hetero atom-containing group.
The linear alkyl group as Ra′10 has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Examples of the branched alkyl group as Ra′10 include those for Ra′3 described above.
The alkyl group in Ra′10 may be partially substituted with a halogen atom or a hetero atom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a hetero atom-containing group. In addition, some of the carbon atoms (those in the methylene group or the like) constituting the alkyl group may be substituted with a hetero atom-containing group.
Examples of the hetero atom mentioned here include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the hetero atom-containing group include (—O—), —C(═O)—O—, —O—C(═O)—, —C(═O)—, —O—C(═O)—O—, —C(═O)—NH—, —NH—, —S—, —S(═O)2—, and —S(═O)2—O—.
In General Formula (a1-r2-1), preferred examples of Ra′11 (a group that forms an aliphatic cyclic group together with the carbon atom to which Ra′10 has been bonded) include the groups described as the examples of the aliphatic hydrocarbon group (alicyclic hydrocarbon group) which is a monocyclic group or a polycyclic group as Ra′3 in General Formula (a1-r-1). Among them, it is preferably a monocyclic alicyclic hydrocarbon group, and specifically, it is more preferably a cyclopentyl group or a cyclohexyl group.
In General Formula (a1-r2-2), examples of the cyclic hydrocarbon group that is formed by Xa together with Ya include a group in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (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 the substituent include those described as the examples of the substituents which may be contained in the cyclic hydrocarbon group as Ra′3.
In General Formula (a1-r2-2), examples of the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms as Ra10′ to Ra103 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 Ra101 to Ra103 include a monocyclic aliphatic saturated hydrocarbon group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, or a cyclododecyl group; and a polycyclic aliphatic saturated hydrocarbon group 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, or an adamantyl group. From the viewpoint of ease of synthesis, Ra101 to Ra103 are preferably a hydrogen atom or a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and particularly preferably a hydrogen atom.
Examples of the substituent contained in the chain-like saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by Ra101 to Ra103 include the same substituents as those for Rax5.
Examples of the group having a carbon-carbon double bond generated by two or more of Ra101 to Ra103 being bonded to each other to form a cyclic structure 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 ease of synthesis.
In General Formula (a1-r2-3), as the aliphatic cyclic group that is formed by Xaa together with Yaa, the group described as the examples of the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group as Ra′3 in General Formula (a1-r-1) is preferable.
In General Formula (a1-r2-3), examples of the aromatic hydrocarbon group as Ra104 include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among the examples, Ra104 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 benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.
Examples of the substituent which may be contained in Ra104 in General Formula (a1-r2-3) include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), and an alkyloxycarbonyl group.
In General Formula (a1-r2-4), Ra′12 and Ra′13 each independently represents a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms as Ra′12 and Ra′13 include those described as the examples of the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms as Ra101 to Ra103. Some or all of the hydrogen atoms contained in the chain-like saturated hydrocarbon group may be substituted.
Among them, 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 group represented by Ra′12 and Ra′13 is substituted, examples of the substituent thereof include the same substituents as those for Ra′.
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 preferably has 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. Among these, 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 preferably has 3 to 6 carbon atoms, and specific examples thereof 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 groups as those for the aromatic hydrocarbon group as Ra104. Among these, 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 groups as those for the substituent which may be contained in Ra104.
In a case where Ra′14 in General Formula (a1-r2-4) represents a naphthyl group, the position bonded to the tertiary carbon atom in General Formula (a1-r2-4) may be the 1-position or the 2-position of the naphthyl group.
In a case where Ra′14 in General Formula (a1-r2-4) represents an anthryl group, the position bonded to the tertiary carbon atom in General Formula (a1-r2-4) may be the 1-position, the 2-position, or the 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.
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 represents 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.
In addition, 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 some of the hydrogen atoms in a hydroxyl group of a constitutional unit derived from hydroxystyrene or a hydroxystyrene derivative are protected by a substituent including the above-described acid-decomposable group; and a constitutional unit in which at least some of the hydrogen atoms in —C(═O)—OH of a constitutional unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative are protected by a substituent including the above-described 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 represents an acid-dissociable group represented by General Formula (a1-r-1) or (a1-r-2). Wa1 represents a (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 in which some or all of the hydrogen atoms in the alkyl group having 1 to 5 carbon atoms have been substituted with a halogen atom. The halogen atom is particularly preferably a fluorine atom.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is most preferable 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 be 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 described above preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, still more preferably has 1 to 4 carbon atoms, and most preferably has 1 to 3 carbon atoms.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, 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 has 3 to 6 carbon atoms, still more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, 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 in which the alicyclic hydrocarbon group is bonded to the terminal of the linear or branched aliphatic hydrocarbon group, and a group in which the alicyclic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same 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 has 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 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 polycycloalkane 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 has 5 to 30 carbon atoms, still more preferably has 5 to 20 carbon atoms, particularly preferably has 6 to 15 carbon atoms, and most preferably has 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 some of the 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 hydrocarbon group include a group obtained by removing two hydrogen atoms 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 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). The alkylene group (an alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably has 1 or 2 carbon atoms, and particularly preferably has 1 carbon atom.
In General Formula (a1-1), Ra1 represents 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 be 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 to tetravalent and more preferably divalent or trivalent.
In the Formula (a1-2), Ra2 represents 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 the formulae shown below, Rα represents a hydrogen atom, a methyl group, or a trifluoromethyl group.
The constitutional unit (a1) contained in the component (A1) may be one 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) 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 formulae, Ra1″ represents an acid-dissociable group represented by General Formula (a1-r2-1), (a1-r2-3), or (a1-r2-4). * represents a bonding site.]
R, Va1, and na1 in General Formula (a1-1-1) each have the same definition as that for 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 a group in which the acid-dissociable group is a cyclic group due to the fact that the reactivity can be increased, which is suitable.
In General Formula (a1-1-1), it is preferable that Ra1″ represent an acid-dissociable group represented by General Formula (a1-r2-1) among the examples described above.
The proportion of the constitutional unit (a1) in the component (A1) is preferably in a range of 5% to 95% by mole, more preferably in a range of 10% to 90% by mole, still more preferably in a range of 30% to 70% by mole, and particularly 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 above-described preferred range, lithography characteristics such as sensitivity, CDU, resolution, and roughness amelioration are improved. On the other hand, in a case where the proportion is equal to or smaller than the upper limit value of the above-described preferred range, balance with other constitutional units can be obtained, and various lithography characteristics are improved.
The component (A1) may have other constitutional units as necessary in addition to the constitutional unit (a1) described above.
Examples of the other constitutional units include a constitutional unit (a2) containing a lactone-containing cyclic group, an —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 (st) derived from styrene or a styrene derivative; and a constitutional unit derived from hydroxystyrene or a hydroxystyrene derivative.
The component (A1) may further have a constitutional unit (a2) (here, those corresponding to the constitutional unit (a1) are excluded) containing a lactone-containing cyclic group, an —SO2— containing cyclic group, or a carbonate-containing cyclic group, in addition to 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. In addition, due to having the constitutional unit (a2), lithography characteristics and the like 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 term “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 a group represented by each of General Formulae (a2-r-1) to (a2-r-7) shown below.
[In the formulae, each Ra′21 independently represents 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 an —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. * represents a bonding site.]
In General Formulae (a2-r-1) to (a2-r-7), it is preferable that the alkyl group as Ra′21 be 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.
It is preferable that the alkoxy group as Ra′21 be 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 described as the examples of the alkyl group represented by Ra′21 to an oxygen atom (—O—).
The halogen atom as Ra′21 is preferably a fluorine atom.
Examples of the halogenated alkyl group as Ra′21 include groups in which some or all hydrogen atoms in the alkyl group as Ra′21 have been substituted with the 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, each R″ represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an —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 has 4 to 12 carbon atoms, and most preferably has 5 to 10 carbon atoms. Specific examples thereof include a group obtained by removing one or more hydrogen atoms from a monocycloalkane, which may 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 as those represented by each of General Formulae (a2-r-1) to (a2-r-7).
The carbonate-containing cyclic group as R″ has the same definition as that for the carbonate-containing cyclic group described below. Specific examples of the carbonate-containing cyclic group include a group represented by each of General Formulae (ax3-r-1) to (ax3-r-3).
The —SO2— containing cyclic group as R″ has the same definition as that for the —SO2— containing cyclic group described below, and specific examples thereof include a group represented by each of General Formulae (a5-r-1) to (a5-r-4).
As the hydroxyalkyl group as Ra′21, a hydroxyalkyl group having 1 to 6 carbon atoms is preferable, and specific examples thereof include a group in which at least one hydrogen atom in the alkyl group as Ra′21 has been substituted with a hydroxyl group.
Among the examples, it is preferable that each Ra′21 independently represent a hydrogen atom or a cyano 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, examples of which 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 group represented by each of General Formulae (a2-r-1) to (a2-r-7) are shown below.
The term “—SO2— containing cyclic group” denotes a cyclic group having a ring containing —SO2— in the ring skeleton thereof. Specifically, the —SO2— containing cyclic group 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 has 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 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, that is, a cyclic group containing a sultone ring in which —O—S— in —O—SO2— forms a part of the ring skeleton thereof.
More specific examples of the —SO2— containing cyclic group include a group represented by each of General Formulae (a5-r-1) to (a5-r-4).
[In the formulae, each Ra′51 independently represents 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 an —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, and * represents a bonding site.]
In General Formulae (a5-r-1) and (a5-r-2), A″ is the same as 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 groups as those for Ra′21 in General Formulae (a2-r-1) to (a2-r-7).
Specific examples of the group represented by each of General Formulae (a5-r-1) to (a5-r-4) are shown below. In the formulae shown below, “Ac” represents an acetyl group.
The term “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 a group represented by each of General Formulae (ax3-r-1) to (ax3-r-3) shown below.
[In the formulae, each Ra′x31 independently represents 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 an —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. * represents a bonding site.]
In General Formulae (ax3-r-2) and (ax3-r-3), A″ is the same as 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 as those described in the explanation of Ra′21 in General Formulae (a2-r-1) to (a2-r-7).
Specific examples of the group represented by each of 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. 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 an —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.
In a case where Ya21 represents a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic 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 be 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.
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.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, 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 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, 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 a substituent 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.
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 in which the cyclic aliphatic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms and more preferably has 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 preferably has 7 to 12 carbon atoms. Specific examples of the polycycloalkane 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 a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more 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 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 in which some or all of the hydrogen atoms in the above-described alkyl groups have been substituted with the above-described halogen atoms.
In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure thereof may be substituted with a substituent having a hetero atom. As the substituent having a hetero atom, —O—, —C(═O)—O—, —S—, —S(═O)2—, or —S(═O)2—O— is preferable.
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 the aromatic ring may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably has 5 to 20 carbon atoms, still more preferably has 6 to 15 carbon atoms, and particularly preferably has 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 include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring obtained by substituting some of the 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 two hydrogen atoms from the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring (an arylene group or a heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound having two or more aromatic rings (for example, biphenyl or fluorene); and a group in which one hydrogen atom of a group (an aryl group or a heteroaryl group) obtained by removing one hydrogen atom from the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring has been substituted with an alkylene group (for example, a group in which one hydrogen atom further has 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 bonded to the aryl group or the heteroaryl group preferably has 1 to 4 carbon atoms, more preferably has 1 or 2 carbon atoms, and particularly preferably has 1 carbon atom.
In 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 a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable.
Examples of the alkoxy group, the halogen atom, and the halogenated alkyl group, as the substituent, include those described as the examples of the substituent that is substituted for a hydrogen atom contained in the cyclic aliphatic hydrocarbon group.
In a case where Ya21 represents a divalent linking group having 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 or an acyl group), —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 represents 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 has 1 to 8 carbon atoms, and particularly preferably has 1 to 5 carbon atoms.
In 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—, Y21 and Y22 each independently represents a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include those described as the examples of the divalent linking group (the divalent hydrocarbon group which may have a substituent) as Ya21.
Y21 preferably represents 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 preferably represents 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 alkylmethylene 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 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. That is, a group represented by Formula —Y21—C(═O)—O—Y22— is particularly preferable as the group represented by Formula —[Y21—C(═O)—O]m—Y22. Among these, a group represented by Formula —(CH2)α—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 examples, it is preferable that Ya21 represent a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof.
In Formula (a2-1), Ra21 represents a lactone-containing cyclic group, an —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 the above-described group represented by each of General Formulae (a2-r-1) to (a2-r-7), a group represented by each of General Formulae (a5-r-1) to (a5-r-4), and a group represented by each of General Formulae (ax3-r-1) to (ax3-r-3).
Among them, a lactone-containing cyclic group or an —SO2— containing cyclic group is preferable, and the group represented by each of General Formula (a2-r-1), (a2-r-2), or (a5-r-1) is more preferable.
Specifically, any group represented by each of Chemical Formulae (r-1c-1-1) to (r-1c-1-7), (r-1c-2-1) to (r-1c-2-18), or (r-s1-1-1), is preferable, any group represented by each of Chemical Formulae (r-1c-2-1) to (r-1c-2-18), or (r-s1-1-1) is more preferable, and any group represented by each of Chemical Formula (r-1c-1-1), (r-1c-2-1), (r-1c-2-12), or (r-s1-1-1) is still more preferable.
The constitutional unit (a2) contained in the component (A1) may be one 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 5% to 95% by mole, more preferably in a range of 10% to 90% by mole, still more preferably in a range of 30% to 70% by mole, and particularly 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 (a2) is equal to or larger than the lower limit value of the above-described 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 the proportion of the constitutional unit (a2) is equal to or smaller than the upper limit value of the above-described preferred range, balance with other constitutional units can be obtained, and various lithography characteristics are improved.
The component (A1) may further have, as necessary, a constitutional unit (a3) (however, a constitutional unit corresponding to the constitutional unit (a1) or the constitutional unit (a2) is excluded) containing a polar group-containing aliphatic hydrocarbon group, in addition to the constitutional unit (a1). 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. In addition, acid diffusion length can be properly adjusted.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group have been substituted 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 contains an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group have been substituted with a fluorine atom is 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 contains an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group have been substituted 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 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, and a constitutional unit containing a polar group-containing aliphatic hydrocarbon group is preferable.
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, as the constitutional unit (a3), in a case where the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, 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) are preferable, and in a case where the hydrocarbon group is a monocyclic group, a constitutional unit represented by General Formula (a3-4) is preferable.
[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 be bonded to the 3- and 5-positions of the adamantyl group. In a case where j represents 1, it is preferable that the hydroxyl group be bonded to the 3-position of the adamantyl group.
It is preferable that j represent 1, and it is particularly preferable that the hydroxyl group be 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- or 6-position of the norbornyl group.
In General Formula (a3-3), it is preferable that t′ represent 1. It is preferable that 1 represent 1. It is preferable that s represent 1. Further, it is preferable that a 2-norbornyl group or 3-norbornyl group be bonded to the terminal of the carboxy group of the acrylic acid. It is preferable that the fluorinated alkyl alcohol be bonded to the 5-position or 6-position of the norbornyl group.
In General Formula (a3-4), it is preferable that t′ represent 1 or 2. It is preferable that 1 represent 0 or 1. It is preferable that s represent 1. It is preferable that the fluorinated alkyl alcohol be bonded to the 3- or 5-position of the cyclohexyl group.
The constitutional unit (a3) contained in the component (A1) may be one or more kinds.
In a case where the component (A1) has the constitutional unit (a3), the proportion of the constitutional unit (a3) is preferably in a range of 1% to 30% by mole, more preferably in a range of 2% to 25% by mole, and still more preferably in a range of 5% to 20% 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 preferred range, the effect obtained by allowing the constitutional unit (a3) to be contained can be sufficiently achieved by the effect described above. In a case where the proportion of the constitutional unit (a3) is equal to or smaller than the upper limit value of the preferred range, balance with other constitutional units can be obtained, and various lithography characteristics are improved.
The component (A1) may further have, in addition to the constitutional unit (a1), a constitutional unit (a4) 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. In addition, 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 term “acid non-dissociable cyclic group” in the constitutional unit (a4) is a cyclic group that remains in the constitutional unit without being dissociated even when an acid acts in a case where the acid is generated in the resist composition by exposure (for example, in a case where acid is generated from the constitutional unit that generates acid upon exposure, or the component (B)).
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, a large number of cyclic groups known in the related art as cyclic groups used as a resin component of a resist composition for ArF excimer laser, KrF excimer laser (preferably 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 a constitutional unit represented by each of General Formulae (a4-1) to (a4-7).
[In the formulae, Rα has the same definition as described above.]
The constitutional unit (a4) contained in the component (A1) may be one or more kinds.
In a case where the component (A1) has the constitutional unit (a4), the proportion of the constitutional unit (a4) is preferably in a range of 10% to 40% by mole and more preferably in a range of 5% to 20% 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 preferred range, the effect that is obtained by allowing the constitutional unit (a4) to be contained can be sufficiently achieved. In a case where the proportion of the constitutional unit (a4) is equal to or smaller than the upper limit value of the preferred range, the balance with other constitutional units is obtained easily.
The constitutional unit (st) is a constitutional unit derived from styrene or a styrene derivative. The term “constitutional unit derived from styrene” means a constitutional unit that is formed by the cleavage of an ethylenic double bond of styrene. The term “constitutional unit derived from a styrene derivative” means a constitutional unit formed by the cleavage of an ethylenic double bond of a styrene derivative.
The term “styrene derivative” means a compound in which at least some of the hydrogen atoms of styrene are substituted with a substituent. Examples of the styrene derivative include a derivative in which the hydrogen atom at the α-position of styrene is substituted with a substituent, a derivative in which one or more hydrogen atoms of the benzene ring of styrene are substituted with a substituent, and a derivative in which the hydrogen atom at the α-position of styrene and one or more hydrogen atoms of the benzene ring are substituted with a substituent.
Examples of the substituent that is substituted for the hydrogen atom at the α-position of styrene include 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 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 some or all of the hydrogen atoms in the alkyl group having 1 to 5 carbon atoms with a halogen atom. The halogen atom is particularly preferably a fluorine atom.
The substituent that is substituted for the hydrogen atom at the α-position of styrene is preferably an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms or a fluorinated alkyl group having 1 to 3 carbon atoms, and still more preferably a methyl group from the viewpoint of industrial availability.
Examples of the substituent that is substituted for the hydrogen atom of the benzene ring of styrene include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl 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 more 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 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 in which some or all of the hydrogen atoms in the above-described alkyl groups have been substituted with the above-described halogen atoms.
The substituent that is substituted for the hydrogen atom of the benzene ring of styrene is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group, and still more preferably a methyl group.
The constitutional unit (st) is preferably a constitutional unit derived from styrene or a constitutional unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, more preferably a constitutional unit derived from styrene, or a constitutional unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with a methyl group, and still more preferably a constitutional unit derived from styrene.
The constitutional unit (st) contained in the component (A1) may be one 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 (a1), and preferred examples thereof include a polymeric compound having a repeating structure of the constitutional unit (a1) and the constitutional unit (a2).
Among them, suitable examples of the component (A1) include a polymeric compound consisting of a repeating structure of the constitutional unit (a1) and the constitutional unit (a2).
In the polymeric compound having a repeating structure of the constitutional unit (a1) and the constitutional unit (a2), the proportion of the constitutional unit (a1) is preferably in a range of 10% to 90% by mole, more preferably in a range of 20% to 80% by mole, still more preferably in a range of 30% to 70% by mole, and particularly preferably in a range of 40% to 60% by mole with respect to the total (100% by mole) of all constitutional units constituting the polymeric compound.
In addition, the proportion of the constitutional unit (a2) in the polymeric compound described above is preferably in a range of 10% to 90% by mole, more preferably in a range of 20% to 80% by mole, still more preferably in a range of 30% to 70% by mole, and particularly preferably in a range of 40% to 60% by mole, with respect to the total amount (100% by mole) of all constitutional units constituting the polymeric compound.
The molar ratio of the constitutional unit (a1) to the constitutional unit (a2) in the polymeric compound (the constitutional unit (a1):the constitutional unit (a2)) is preferably in a range of 2:8 to 8:2, more preferably in a range of 3:7 to 7:3, and still more preferably in a range of 4:6 to 6:4.
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.
It should be noted that a —C(CF3)2—OH group may be introduced into the terminal during the polymerization by using, in combination, a chain transfer agent such as HS—CH2—CH2—CH2—C(CF3)2—OH. As described above, a copolymer into which a hydroxyalkyl group, formed by substitution of some of the hydrogen atoms in the alkyl group with fluorine atoms, 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) (in terms of 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 this preferred range, the resist composition exhibits sufficient solubility in a resist solvent such that the resist composition can be used as a resist. On the other hand, in a case where Mw thereof is equal to or larger than the lower limit value of this 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 the resist composition according to the present embodiment, a base material component (hereinafter, referred to as a “component (A2)”) that exhibits changed solubility in a developing solution under action of acid, which does not correspond to the component (A1), may be used in combination as the component (A).
The component (A2) is not particularly limited and may be freely selected and used from a large number of base material components for the chemical amplification-type resist composition known in the related art.
As the component (A2), a polymeric compound or a low-molecular-weight compound may be used alone or in a combination of two or more kinds thereof.
The proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, and still more preferably 75% by mass or more, and it may be 100% by mass with respect to the total mass of the component (A). In a case where the proportion is 25% by mass or more, a resist pattern having various excellent lithography characteristics such as high sensitivity, resolution, and roughness amelioration can be easily formed.
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.
The component (B) in the resist composition according to the present embodiment includes a compound (B0) having a molar absorption coefficient of 50,000 mol−1·L·cm−1 or less at an exposure wavelength of 193 nm (hereinafter, also referred to as a “component (B0)”).
The molar absorption coefficient of the component (B0) at an exposure wavelength of 193 nm is 50,000 mol−1·L·cm−1 or less, and it is preferably 25,000 mol−1·L·cm−1 or more and 50,000 mol−1·L·cm−1 or less, more preferably 25,000 mol−1·L·cm−1 or more and 45,000 mol−1·L·cm−1 or less, still more preferably 30,000 mol−1·L·cm−1 or more and 42,000 mol−1·L·cm−1 or less, and particularly preferably 35,000 mol−1·L·cm−1 or more and 42,000 mol−1·L·cm−1 or less.
In a case where the molar absorption coefficient of the component (B0) at an exposure wavelength of 193 nm is 50,000 mol−1·L·cm−1 or less, the transmittance of light (typically, an ArF excimer laser) of the resist film that is formed from the resist composition containing the component (B0) is improved, and a reaction by which acid is generated from the component (B0) in the resist film is likely to be uniformly carried out, whereby the shape of the resist pattern and the roughness reduction property are improved.
In a case where the molar absorption coefficient of the component (B0) at an exposure wavelength of 193 nm is equal to or smaller than the above-described preferred upper limit value, a reaction by which acid is generated from the component (B0) in the resist film is more uniformly carried out, whereby the shape of the resist pattern and the roughness reduction property are further improved.
In a case where the molar absorption coefficient of the component (B0) at an exposure wavelength of 193 nm is equal to or larger than the above-described preferred lower limit value, the sensitivity in the resist pattern formation is further improved.
In the present specification, the molar absorption coefficient of the component (B0) means a value obtained by measuring the absorbance of the component (B0) at a wavelength of 193 nm with a spectrophotometer and carrying out a calculation using the Lambert-Beer law.
Specifically, the component (B0) is dissolved in acetonitrile, this solution is placed in a cell having an optical path length of 10 mm, the UV spectrum is measured with a spectrophotometer (UV-3600, manufactured by Shimadzu Corporation), and the absorbance at a wavelength of 193 nm is acquired. Next, the molar absorption coefficient s (mol−1·L·cm−1) can be calculated from the obtained absorbance and the solution concentration using the Lambert-Beer law.
The component (B0) is preferably a compound (B01) represented by General Formula (b01).
[In the formula, X− represents a counter anion. Rb01 to Rb13 each independently represents an aryl group, an alkyl group, or an alkenyl group. The aryl group, the alkyl group, and the alkenyl group each independently may have, as a substituent, one or more substituents selected from the group consisting of an alkyl group, an aldehyde group, an acyl group, a hydroxy group, and a halogen atom. Rb01 to Rb03 may be bonded to each other to form a ring with a sulfur atom in the formula].
In General Formula (b01), X− represents a counter anion. X− is not particularly limited, and those which have been proposed as an anion moiety of an acid generator for a chemical amplification-type resist composition in the related art can be used.
Examples of X− include an anion represented by General Formula (b0-1-an), General Formula (b0-2-an), or General Formula (b0-3-an).
[In the formulae, R101 and R104 to R108 each independently 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. 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 having an oxygen atom or a single bond. V101 to V103 each independently represents a single bond, an alkylene group, or a fluorinated alkylene group. L101 and L102 each independently represents a single bond or an oxygen atom. L103 to L105 each independently represents a single bond, —CO—, or —SO2—.]
In General Formula (b0-1-an), 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 be saturated.
The aromatic hydrocarbon group as R101 is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably has 5 to 30, still more preferably has 5 to 20, particularly preferably has 6 to 15, and most preferably has 6 to 10. However, 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 in which some carbon atoms constituting any of these aromatic rings have been substituted with hetero atoms. 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 in which one hydrogen atom has been removed from the aromatic ring (an aryl group such as a phenyl group or a naphthyl group) and a group in which one hydrogen atom in the aromatic ring has been substituted with an alkylene 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). The alkylene group (an alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably has 1 or 2 carbon atoms, and particularly preferably has 1 carbon atom.
Examples of the cyclic aliphatic hydrocarbon group as R101 include an aliphatic hydrocarbon group having a ring in the structure thereof. The cyclic aliphatic hydrocarbon group as R101 preferably has 3 to 50 carbon atoms, more preferably has 4 to 45 carbon atoms, and still more preferably has 5 to 40 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 one hydrogen atom from an aliphatic hydrocarbon ring), a group in which the alicyclic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group, and a group in which the alicyclic hydrocarbon group is interposed in a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms and more preferably has 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, the polycycloalkane is more preferably 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.
Among these examples, as the cyclic aliphatic hydrocarbon group as R101, a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane is preferable, a group in which one hydrogen atom has been removed from a polycycloalkane is more preferable, an adamantyl group or a norbornyl group is still more preferable, and an adamantyl group is particularly preferable.
The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, still more preferably has 1 to 4 carbon atoms, and most preferably has 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, 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 has 3 to 6 carbon atoms, still more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, 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.
In addition, the cyclic hydrocarbon group as R101 may have a hetero atom such as a heterocyclic ring. Specific examples thereof include the lactone-containing cyclic group represented by each of General Formulae (a2-r-1) to (a2-r-7), the —SO2— containing cyclic group represented by each of General Formulae (a5-r-1) to (a5-r-4), and another heterocyclic group represented by each of Chemical Formulae (r-hr-1) to (r-hr-16). In the formulae, * represents a bonding site to which Y101 in General Formula (b0-1-an) is bonded.
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 hydroxy 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 some or all of the 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 substitutes a methylene group (—CH2—) constituting the cyclic hydrocarbon group.
The cyclic hydrocarbon group as R101 may be a condensed cyclic group having a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed. 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 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) and (r-br-2). In the formulae, * represents a bonding site to which Y101 in General Formula (b0-1-an) is bonded.
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 those described as the examples of 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 obtained by removing one hydrogen atom from the above-described aromatic ring (an aryl group; for example, a phenyl group or a naphthyl group), a group in which one hydrogen atom in the aromatic ring has been substituted with an alkylene 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), and the heterocyclic group represented by each of 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 in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane; a group in which one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; the lactone-containing cyclic group represented by each of General Formulae (a2-r-1) to (a2-r-7); the —SO2— containing cyclic group represented by each of General Formulae (a5-r-1) to (a5-r-4); and the heterocyclic group represented by each of Formulae (r-hr-7) to (r-hr-16).
The cyclic hydrocarbon group as R101 may be a group linked by a linear or branched aliphatic hydrocarbon group in which two or more aliphatic rings and/or aromatic rings may have a substituent. In the linear or branched aliphatic hydrocarbon group that links the alicyclic hydrocarbon group, a methylene group (—CH2—) constituting the aliphatic hydrocarbon chain may be substituted with a divalent group containing a hetero atom. Examples of the divalent group containing a hetero atom include (—O—), —C(═O)—O—, —O—C(═O)—, —C(═O)—, —O—C(═O)—O—, —C(═O)—NH—, —NH—, —S—, —S(═O)2—, and —S(═O)2—O—.
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 has 1 to 15 carbon atoms, and most preferably has 1 to 10 carbon atoms.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably has 3 to 15 carbon atoms, and most preferably has 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:
The chain-like alkenyl group as R101 may be linear or branched, and the number of carbon atoms thereof is preferably in a range of 2 to 10, more preferably in a range of 2 to 5, still more preferably in a range of 2 to 4, and particularly preferably 3. 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 for 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 chain-like alkyl group which may have a substituent, or an alicyclic hydrocarbon group which may have a substituent, more preferably a chain-like alkyl group which may have a halogen atom, a group obtained by removing one or more hydrogen atoms from a polycycloalkane which may have a substituent, or the —SO2— containing cyclic group represented by each of General Formulae (a5-r-1) to (a5-r-4), still preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane which may have a substituent, or the —SO2— containing cyclic group represented by each of General Formulae (a5-r-1) to (a5-r-4), and particularly preferably an adamantyl group which may have a hydroxy group, or the —SO2— containing cyclic group represented by General Formula (a5-r-1).
In a case where the alicyclic hydrocarbon group has a substituent, the substituent is preferably a hydroxy group.
In General Formula (b0-1-an), 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 the atom 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. Further, a sulfonyl group (—SO2—) may be further linked to the combination. Examples of such a divalent linking group containing an oxygen atom include a linking group represented by each of General Formulae (y-a1-1) to (y-a1-7) shown below. In General Formulae (y-a1-1) to (y-a1-7), the one that is bonded to R101 in General Formula (b0-1-an) is V′101 in General Formulae (y-a1-1) to (y-a1-7).
[In the formulae, V′101 represents a single bond or an alkylene group having 1 to 5 carbon atoms, and V′102 represents a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]
As the divalent saturated hydrocarbon group as V′102, an alkylene group having 1 to 30 carbon atoms is preferable, an alkylene group having 1 to 10 carbon atoms is more preferable, and an alkylene group having 1 to 5 carbon atoms is still more preferable.
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′402 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—].
In addition, some of the 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. As the aliphatic cyclic group, a divalent group in which one hydrogen atom has been further 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) is preferable, and a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferable.
Y101 preferably represents a divalent linking group having an ester bond or a divalent linking group having an ether bond, more preferably the linking group represented by each of Formulae (y-a1-1) to (y-a1-5), and still more preferably the linking group represented by General Formula (y-a1-1) or (y-a1-3).
In General Formula (b0-1-an), V101 represents a single bond, an alkylene group, or a fluorinated alkylene group. It is preferable that the alkylene group and the fluorinated alkylene group as V101 have 1 to 4 carbon atoms. Examples of the fluorinated alkylene group as V101 include a group in which some or all hydrogen atoms in the alkylene group as V101 have been substituted with fluorine atoms. Among the above, V101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms, and it is more preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.
In General Formula (b0-1-an), 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 (b0-1-an) 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 formulae, R″101 represents an aliphatic cyclic group which may have a substituent, the monovalent heterocyclic group represented by each of Chemical Formulae (r-hr-1) to (r-hr-6), the condensed cyclic group represented by General Formula (r-br-1) or (r-br-2), or a chain-like alkyl group which may have a substituent. R″102 represents an aliphatic cyclic group which may have a substituent, the condensed cyclic group represented by General Formula (r-br-1) or (r-br-2), the lactone-containing cyclic group represented by each of General Formulae (a2-r-1) and (a2-r-3) to (a2-r-7), or the —SO2— containing cyclic group represented by each of 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 described as the examples of the cyclic aliphatic hydrocarbon group as R101 in General Formula (b0-1-an). Examples of the substituent include the same as the substituent that may be substituted for the cyclic aliphatic hydrocarbon group as R101 in General Formula (b0-1-an).
The aromatic cyclic group which may have a substituent, as R″103, is preferably the group described as the examples of the aromatic hydrocarbon group for the cyclic hydrocarbon group as R101 in General Formula (b0-1-an). Examples of the substituent include the same as the substituent that may be substituted for the aromatic hydrocarbon group as R101 in General Formula (b0-1-an).
The chain-like alkyl group as R101, which may have a substituent, is preferably the group described as the examples of the chain-like alkyl group as R101 in General Formula (b0-1-an).
The chain-like alkenyl group as R″103, which may have a substituent, is preferably the group described as the examples of the chain-like alkenyl group as R101 in General Formula (b0-1-an).
Specific examples of the anion represented by General Formula (b0-1-an) are shown below; however, the specific examples thereof are not limited thereto.
In General Formula (b0-2-an), R104 and R105 each independently 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 each includes the same as R101 in General Formula (b0-1-an). Here, R′04 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 has 1 to 7 carbon atoms, and still more preferably has 1 to 3 carbon atoms. It is preferable that the number of carbon atoms in the chain-like alkyl group as R104 and R105 decrease within the range of the number of carbon atoms from the viewpoint that the solubility in a solvent for a resist is also satisfactory. In addition, in the chain-like alkyl group as R104 and R105, it is preferable that the number of hydrogen atoms substituted with fluorine atoms be as large as possible from the viewpoint that the acid strength increases and the transparency to high energy light or electron beams having a wavelength of 250 nm or less 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 be a perfluoroalkyl group in which all hydrogen atoms be substituted with a fluorine atom.
in General Formula (b0-2-an), V102 and V103 each independently represents a single bond, an alkylene group, or a fluorinated alkylene group, and examples thereof each includes the same as V101 in General Formula (b0-1-an).
In General Formula (b0-2-an), L101 and L102 each independently represents a single bond or an oxygen atom.
In General Formula (b0-3-an), R106 to R108 each independently 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 groups as those for R101 in General Formula (b0-1-an).
In General Formula (b0-3-an), L103 to L105 each independently represents a single bond, —CO—, or —SO2—.
Among the above, X− in General Formula (b01) is preferably an anion represented by General Formula (b0-1-an). Among the examples, an anion represented by any one of General Formulae (an-1) to (an-3) is more preferable, an anion represented by General Formula (an-1) or (an-2) is still more preferable, and an anion represented by General Formula (an-1) is particularly preferable.
In General Formula (b01), Rb01 to Rb03 each independently represents an aryl group, an alkyl group, or an alkenyl group.
The aryl group as Rb01 to Rb03 is preferably an aryl group having 6 to 20 carbon atoms, and more preferably a phenyl group or a naphthyl group.
Examples of the alkyl group as Rb01 to Rb03 include a chain-like or cyclic alkyl group, where an alkyl group having 1 to 30 carbon atoms is preferable.
The alkenyl group as Rb01 to Rb03 is preferably an alkenyl group having 2 to 10 carbon atoms.
The aryl group, the alkyl group, and the alkenyl group, as Rb01 to Rb03, each independently may have, as a substituent, one or more substituents selected from the group consisting of an alkyl group, an aldehyde group, an acyl group, a hydroxy group, and a halogen atom.
Among the above, the substituent is preferably an alkyl group.
The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, and still more preferably a tert-butyl group.
In a case where Rb01 to Rb03 are bonded to each other to form a ring together with a sulfur atom in the formula, these groups may be bonded to each other through 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, it is preferable that a ring containing the sulfur atom in the formula in the ring skeleton thereof be a 3-membered to 10-membered ring and it is particularly preferable that it be a 5-membered to 7-membered ring, in a case where the sulfur atom is included. Specific examples of the ring to be formed include a thiophene ring, a thiazole 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.
Among the above, it is preferable that any two of Rb01 to Rb03 be bonded to each other to form a ring together with the sulfur atom in the formula, and it is more preferable that any two of Rb01 to Rb03 be bonded to each other to form a benzothiophene ring together with the sulfur atom in the formula.
Typically, the molar absorption coefficient of the component (B0) can be controlled by appropriately changing the structure of the cation moiety of the component (B0).
Among the above, the cation moiety of the component (B0) is preferably a cation represented by General Formula (b0-1-ca).
[In the formula, R001 represents a hydrogen atom, an alkyl group, an aldehyde group, an acyl group, a hydroxy group, or a halogen atom.]
In General Formula (b0-1-ca), R001 represents a hydrogen atom, an alkyl group, an aldehyde group, an acyl group, a hydroxy group, or a halogen atom.
Among the above, R001 is preferably an alkyl group, an aldehyde group, an acyl group, a hydroxy group, or a halogen atom, more preferably an alkyl group having 1 to 5 carbon atoms, still more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, and particularly preferably a tert-butyl group.
Specific examples of the cation represented by General Formula (b0-1-ca) are shown below; however, the specific examples thereof are not limited thereto.
The cation moiety of the component (B0) is preferably a cation represented by any one of Chemical Formulae (ca-b0-1) to (ca-b0-3), more preferably a cation represented by Chemical Formula (ca-b0-1) or (ca-b0-2), and still more preferably a cation represented by Chemical Formula (ca-b0-1).
Among the above, the component (B0) is preferably a compound (B011) (hereinafter, also referred to as a “component (B011)”) represented by General Formula (b01-1).
[In the formula, X− represents a counter anion. R001 represents a hydrogen atom, an alkyl group, an aldehyde group, an acyl group, a hydroxy group, or a halogen atom.]
The anion moiety of the component (B011) is the same as the anion moiety of the component (B01) described above.
The cation moiety of the component (B011) is the same as the cation represented by General Formula (b0-1-ca).
Specific examples of the component (B0) are shown below; however, the specific examples thereof are not limited thereto. In addition, the molar absorption coefficient ε(mol−1·L·cm−1) calculated according to the method described above is also shown.
In the resist composition according to the present embodiment, the component (B0) may be used alone or may be used in a combination of two or more kinds thereof.
In the resist composition according to the present embodiment, the content of the component (B0) is preferably in a range of 3 to 40 parts by mass, more preferably in a range of 5 to 30 parts by mass, and still more preferably in a range of 10 to 20 parts by mass with respect to 100 parts by mass of the component (A).
In a case where the content of the component (B0) is equal to or larger than the lower limit value of the above-described preferred range, lithography characteristics such as sensitivity, reduction of linewise roughness (LWR), and a pattern shape are further improved in the resist pattern formation. On the other hand, in a case where the content thereof is equal to or smaller than the upper limit value of the preferred range, a homogeneous solution is easily obtained when each of the components of the resist composition is dissolved in an organic solvent, and the storage stability as a resist composition is further improved.
The proportion of the component (B0) in the total component (B) contained in the resist composition according to the present embodiment is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 95% by mass or more. The proportion of the component (B0) in the total component (B) may be 100% by mass.
The component (B) in the resist composition according to the present embodiment may contain an acid generator component (B1) other than the above-described component (B0) (hereinafter, also referred to as a “component (B1)”.
The component (B1) is an acid generator having a molar absorption coefficient of more than 50,000 mol−1·L·cm−1 at an exposure wavelength of 193 nm and is an acid generator in which the cation moiety is typically a cation moiety different from the cation moiety of the component (B0) described above.
Examples of the component (B1) are numerous and include onium salt-based acid generators (however, a component corresponding to the component (B0) is excluded) such as an iodonium salt and a sulfonium salt; an oxime sulfonate-based acid generator; diazomethane-based acid generators such as bisalkyl or bisaryl sulfonyl diazomethanes and poly(bis-sulfonyl)diazomethanes; nitrobenzylsulfonate-based acid generators; iminosulfonate-based acid generators; and disulfone-based acid generators.
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)”), which are described below.
[In the formulae, R101 and R104 to R108 each independently 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. 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 having an oxygen atom or a single bond. V101 to V103 each independently represents a single bond, an alkylene group, or a fluorinated alkylene group. L101 and L102 each independently represents a single bond or an oxygen atom. L103 to L105 each independently represents a single bond, —CO—, or —SO2—. m represents an integer of 1 or more, and M′m+ represents an m-valent onium cation]
The anion moiety in the component (b-1) is an anion represented by General Formula (b0-1-an).
The anion moiety in the component (b-2) is an anion represented by General Formula (b0-2-an).
The anion moiety in the component (b-3) is an anion represented by General Formula (b0-3-an).
In Formulae (b-1), (b-2), and (b-3), M′m+ represents an m-valent onium cation. Among these, 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 an organic cation represented by each of General Formulae (ca-1) to (ca-5) described below.
[In the formulae, R201 to R207, R211, and R212 each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. R201 to R203, R206 and R207, and R211 and R212 may be bonded to each other to form a ring with the sulfur atom in the formulae. R208 and R209 each independently represents 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 an SO2-containing cyclic group which may have a substituent. L201 represents —C(═O)— or —C(═O)—O—. Y201's each 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. Among these, 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, and the number of carbon atoms thereof is preferably in a range of 1 to 30. It is preferable that the alkenyl group as R201 to R207, R211, and R212 have 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 a group represented by each of General Formulae (ca-r-1) to (ca-r-7).
[In the formulae, R′201's each 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.]
In General Formulae (ca-1) to (ca-5), in a case where R201 to R203, R206 and R207, and 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, it is preferable that a ring containing the sulfur atom in the formula in the ring skeleton thereof be a 3-membered to 10-membered ring and it is particularly preferable that it be a 5-membered to 7-membered ring, in a case where the sulfur atom is included. Specific examples of the ring to be formed include a thiophene ring, a thiazole 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 represents 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 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 an 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. Among these, a phenyl group or a naphthyl group is preferable.
The alkyl group as R210 is preferably a chain-like or cyclic alkyl group, where it preferably has 1 to 30 carbon atoms.
It is preferable that the alkenyl group as R210 have 2 to 10 carbon atoms. As the —SO2— containing cyclic group as R210 which may have a substituent, “—SO2— containing polycyclic group” is preferable, and a group represented by General Formula (a5-r-1) is more preferable.
Y201's each independently represents an arylene group, an alkylene group, or an alkenylene group.
Examples of the arylene group as Y201 include a group obtained by removing one hydrogen atom from the aryl group described as the examples of the above-described aromatic hydrocarbon group represented by R101 in General Formula (b0-1-an).
Examples of the alkylene group and alkenylene group as Y201 include a group obtained by removing one hydrogen atom from the group described as the examples of the above-described chain-like alkyl group or chain-like alkenyl group as R101 in General Formula (b0-1-an).
In General Formulae (ca-4) and (ca-5), x represents 1 or 2.
W201 represents an (x+1)-valent linking group, that is, a divalent or trivalent linking group.
As the divalent linking group represented by W201, a divalent hydrocarbon group which may have a substituent is preferable, and examples thereof include the same divalent hydrocarbon groups which may have a substituent as those for Ya21 in General Formula (a2-1). The divalent linking group as W201 may be either linear, branched, or cyclic, and is preferably cyclic. Among these, a group in which two carbonyl groups are combined with both ends of the arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group. Among these, a phenylene group is particularly preferable.
Examples of the trivalent linking group as W201 include a group in which one hydrogen atom has been removed from the above-described divalent linking group as W201 and a group obtained by bonding the divalent linking group to another divalent linking group described above. As the trivalent linking group as W201, a group obtained by bonding two carbonyl groups to an arylene group is preferable.
Among the above, as the cation moiety ((M′m+)1/m), a cation represented by General Formula (ca-1) is preferable.
Specific examples of the suitable cation represented by General Formula (ca-1) include a cation represented by each of Chemical Formulae (ca-1-1) to (ca-1-47) shown below.
[In the formulae, g1, g2, and g3 represent the numbers of repetitions, g1 is an integer in a range of 1 to 5, g2 is an integer in a range of 0 to 20, and g3 is an integer in a range of 0 to 20.]
In the resist composition according to the present embodiment, the component (B31) may be used alone or in a combination of two or more kinds thereof.
The content of the component (B1) is preferably less than 40 parts by mass, more preferably in a range of 0 to 20 parts by mass, and still more preferably in a range of 0 to 5 parts by mass with respect to 100 parts by mass of the component (A).
In a case where the content of the component (B1) is set in the above-described preferred range, lithography characteristics such as sensitivity, reduction of linewise roughness (LWR), and a pattern shape are further improved in the resist pattern formation. In addition, in a case where each component of the resist composition is dissolved in an organic solvent, a homogeneous solution is easily obtained, and the storage stability of the resist composition is improved.
It is preferable that the resist composition according to the present embodiment not contain the component (B1).
The component (D) in the resist composition according to the present embodiment contains a compound (D0) represented by General Formula (d0) (hereinafter, also referred to as a “component (D0)”).
Rd01-Yd01-CH2—SO3⊖(Mm⊕)1/m (d0)
[In the formula, Rd01 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. Yd01 represents a divalent linking group containing an oxygen atom. m represents an integer of 1 or more, and Mm+ represents an m-valent organic cation.]
In General Formula (d0), Rd01 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.
Among these, it is preferable that Rd01 represent 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 that may be included in these groups include a hydroxy group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, the lactone-containing cyclic group represented by each 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, it may be bonded through an alkylene group, and the substituent in this case is preferably a linking group represented by each of General Formulae (y-a1-1) to (y-a1-5).
In a case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-like alkyl group, as Rd01, has a linking group represented by each of General Formulae (y-a1-1) to (y-a1-7) as a substituent, the group that is bonded to a carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-like alkyl group, as Rd01, in General Formulae (y-a1-1) to (y-a1-7), is V′101 in General Formulae (y-a1-1) to (y-a1-7).
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) including a bicyclooctane skeleton.
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, the polycycloalkane is more preferably a polycycloalkane having a bridged ring-based polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane.
The alicyclic hydrocarbon group may be an aliphatic heterocyclic group containing a hetero atom, such as a heterocyclic ring. Specific examples of the aliphatic heterocyclic group include the lactone-containing cyclic group represented by each of General Formulae (a2-r-1) to (a2-r-7), the —SO2— containing cyclic group represented by each of General Formulae (a5-r-1) to (a5-r-4), and the heterocyclic group represented by each of Chemical Formulae (r-hr-1) to (r-hr-16).
It should be noted that * in the lactone-containing cyclic group represented by each of General Formulae (a2-r-1) to (a2-r-7), the —SO2— containing cyclic group represented by each of General Formulae (a5-r-1) to (a5-r-4), and the heterocyclic group represented by each of Chemical Formulae (r-hr-1) to (r-hr-16) represents a bonding site for bonding to Yd01 in General Formula (d0).
Among the above, the aliphatic heterocyclic group is preferably the lactone-containing cyclic group represented by each of General Formulae (a2-r-1) to (a2-r-7), more preferably the lactone-containing cyclic group represented by General Formula (a2-r-7), and still more preferably the group represented by Chemical Formula (r-1c-7-1).
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 10 carbon atoms, more preferably has 1 to 8 carbon atoms, still more preferably has 1 to 6 carbon atoms, and particularly preferably has 1 to 4 carbon atoms.
The number of fluorine atoms in the fluorinated alkyl group is preferably in a range of 1 to 21, and more preferably in a range of 3 to 9.
In General Formula (d0), Rd01 is preferably, among the above, a cyclic group which may have a substituent, and more preferably an alicyclic hydrocarbon group which may have a substituent. It is still more preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane; a group obtained by removing one or more hydrogen atoms from a polycycloalkane; or the lactone-containing cyclic group represented by each of General Formulae (a2-r-1) to (a2-r-7).
In General Formula (d0), Yd01 represents a divalent linking group containing an oxygen atom.
Examples of the divalent linking group containing an oxygen atom, Yd01 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. Further, a sulfonyl group (—SO2—) may be further linked to the combination. More specific examples thereof include the linking group represented by each of General Formulae (y-a1-1) to (y-a1-7). It should be noted that the one that is bonded to Rd01 is V′101 in General Formulae (y-a1-1) to (y-a1-7).
In General Formula (d0), Yd01 is preferably, among the above, the linking group represented by each of General Formulae (y-a1-1) to (y-a1-7), more preferably the linking group represented by General Formula (y-a1-1) or (y-a1-3), and still more preferably the linking group represented by General Formula (y-a1-1).
In a case where in General Formula (d0), Yd01 represents the linking group represented by General Formula (y-a1-1), V′101 in General Formula (y-a1-1) is preferably a single bond.
In addition, V′102 is preferably a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, more preferably a divalent saturated hydrocarbon group having 1 to 16 carbon atoms, and still more preferably a divalent saturated hydrocarbon group having 1 to 10 carbon atoms.
Among the above, the anion moiety of the component (D0) is preferably an anion represented by General Formula (d0-1-an).
[In the formula, Rd01 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. n01 represents an integer in a range of 1 to 10.]
Rd01 in General Formula (d0-1-an) is the same as Rd01 in General Formula (d0).
n01 represents an integer in a range of 1 to 10, and it is preferably an integer in a range of 1 to 5, and more preferably an integer in a range of 1 to 3.
Specific examples of the anion moiety of the component (D0) are shown below; however, the specific examples thereof are not limited thereto.
In General Formula (d0), m represents an integer of 1 or more, and Mm+ represents an m-valent organic cation.
Suitable examples of the organic cation as Mm+ include the cation represented by General Formulae (b0-1-ca) and the cation represented by each of General Formulae (ca-1) to (ca-5), where the cation represented by General Formula (ca-1) is preferable.
Among the above, the component (D0) is preferably a compound (D0) (hereinafter, also referred to as a “component (D01)”) represented by General Formula (d01).
[In the formula, Rd01 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, n01 represents an integer in a range of 1 to 10. m represents an integer of 1 or more, and Mm+ represents an m-valent organic cation.]
The anion moiety of the component (D01) is the same as the anion represented by General Formula (d0-1-an).
The cation moiety of the component (D01) is the same as the cation moiety of the component (D0).
Specific examples of the component (D0) are shown below; however, the specific examples thereof are not limited thereto.
In the resist composition according to the present embodiment, the component (D0) may be used alone or may be used 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 0.1 to 15 parts by mass, more preferably in a range of 1 to 12 parts by mass, and still more preferably in a range of 2 to 10 parts by mass, with respect to 100 parts by mass of the component (A).
In a case of setting the content of the compound (D0) to be equal to or larger than the lower limit value of the above-described preferred range, better lithography characteristics can be easily obtained. On the other hand, in a case where it is equal to or smaller than the above-described preferred upper limit value, the sensitivity is well maintained, and the throughput is also excellent.
In the resist composition according to the present embodiment, the proportion of the component (D0) in the total amount of the component (D) is, for example, 50% by mass or greater, preferably 70% by mass or greater, and more preferably 95% by mass or greater. The proportion of the component (D0) in the total amount of the component (D) may be 100% by mass.
The component (D) in the resist composition according to the present embodiment may contain an acid diffusion-controlling agent other than the component (D0) described above.
Examples of the acid diffusion-controlling agent other than the component (D0) described above include a photodecomposable base (D1) other than the component (D0) (hereinafter, referred to as a “component (D1)”), and a nitrogen-containing organic compound (D2) (hereinafter, referred to as a “component (D2)”) that does not correspond to the component (D0) and the component (D1).
The component (D1) is not particularly limited as long as it is decomposed 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)”).
At exposed portions of the resist film, the components (d1-1) to (d1-3) are decomposed and then lose the acid diffusion controllability (basicity), and thus they cannot act as a quencher, whereas they act as a quencher at unexposed portions of the resist film.
It should be noted that in the compounds represented by General Formula (d1-2), those corresponding to the compound (D0) are excluded.
[In the formulae, Rd1 to Rd4 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. Here, no fluorine atom is bonded to the carbon atom adjacent to the S atom in Rd2 of General Formula (d1-2). Yd1 represents a single bond or a divalent linking group. m represents an integer of 1 or more, and Mm+'s each independently represents an m-valent organic cation.]
{Component (d1-1)}
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 groups as those for R′201.
Among these, it is preferable that Rd1 represent 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 that may be included in these groups include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, the lactone-containing cyclic group represented by each 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, it may be bonded through an alkylene group, and the substituent in this case is preferably a linking group represented by each of General Formulae (y-a1-1) to (y-a1-5). It should be noted that in a case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-like alkyl group, as Rd1, has a linking group represented by each of General Formulae (y-a1-1) to (y-a1-7) as a substituent, the group that is bonded to a carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-like alkyl group, as Rdt in General Formula (d1-1), is V′101 in General Formulae (y-a1-1) to (y-a1-7).
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) including a 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 has 1 to 8 carbon atoms, and still more preferably has 1 to 4 carbon atoms. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atom other than a fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specific examples of the preferred anion moiety for the component (d1-1) are shown below.
In General Formula (d1-1), M3+ represents an m-valent organic cation.
The suitable examples of the organic cation as Wm+ include the same as the cation represented by each of General Formulae (ca-1) to (ca-3), and the cation represented by General Formula (ca-1) is more preferable.
The component (d1-1) may be used alone or in a combination of two or more kinds thereof.
{Component (d1-2)}
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 groups as those for R′201.
Here, no fluorine atom is bonded to the carbon atom adjacent to the S atom in Rd2 (the carbon atom is not substituted with fluorine). 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, and more preferably an aliphatic cyclic group which may have a substituent.
The chain-like alkyl group preferably has 1 to 10 carbon atoms and more preferably has 3 to 10 carbon atoms.
The aliphatic cyclic group is more preferably a group (which may have a substituent) obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; and a group obtained by removing one or more hydrogen atoms from camphor.
The hydrocarbon group as Rd2 may have a substituent, and examples of the substituent include a hydroxy group, an oxo group, an alkyl group, an aryl group, a halogen atom, and a halogenated alkyl group.
Specific examples of the preferred anion moiety for the component (d1-2) are shown below.
In General Formula (d1-2), Mm+ represents an m-valent organic cation and has the same definition as that for Mm+ in General Formula (d1-1).
The component (d1-2) may be used alone or in a combination of two or more kinds thereof.
{Component (d1-3)}
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 groups as those for R′201. Among these, a cyclic group having a fluorine atom, a chain-like alkyl group, or a chain-like alkenyl group is preferable. Among these, a fluorinated alkyl group is preferable, and the same groups as those for the fluorinated alkyl group represented by Rd1 are 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 groups as those for R′201.
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.
It is preferable that the alkyl group as Rd4 be 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. Some hydrogen atoms in the alkyl group as Rd4 may be substituted with a hydroxyl group, a cyano group, or the like.
It is preferable that the alkoxy group as Rd4 be 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 these, a methoxy group and an ethoxy group are preferable.
Examples of the alkenyl group as Rd4 include the same groups as those for the alkenyl group as R′201. Among these, a vinyl group, a propenyl group (an allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group are 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 groups as those for the cyclic group as R′21. Among these, an alicyclic group in which one or more hydrogen atoms have been removed 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 is preferable. In a case where Rd4 represents an alicyclic group, the resist composition is satisfactorily dissolved in an organic solvent so that the lithography characteristics are enhanced. In addition, in a case where Rd4 represents an aromatic group, the resist composition has an excellent light absorption efficiency in lithography using EUV or the like as a light source for exposure, and thus the sensitivity and lithography characteristics are enhanced.
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 having a hetero atom. Examples of the divalent linking groups are the same as those for the divalent hydrocarbon group which may have a substituent, and the divalent linking group having a hetero atom described in the section of the divalent linking group as Yan in General Formula (a2-1).
It is preferable that Yd1 represent a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and still more preferably a methylene group or an ethylene group.
Specific examples of the preferred anion moiety for the component (d1-3) are shown below.
In General Formula (d1-3), Mm+ represents an m-valent organic cation and has the same definition as that for Mm+ in General Formula (d1-1).
The component (d1-3) may be used alone or in a combination of two or more kinds thereof.
As the component (D1), only one of the above-described components (d1-1) to (dC-3) or a combination of two or more kinds thereof may be used.
The content of the component (D1) is preferably 20 parts by mass or less, more preferably in a range of 0 to 15 parts by mass, and still more preferably in a range of 0 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 (D1) is within the preferred range, excellent lithography characteristics and an excellent resist pattern shape are easily obtained.
It is preferable that the resist composition according to the present embodiment not contain the component (D1).
The methods of producing the components (d1-1) and (d1-2) described above are not particularly limited, and the components (d1-1) and (d1-2) can be produced by conventionally known methods.
In addition, the method of producing the component (d1-3) is not particularly limited, and the component (d1-3) can be produced, for example, in the same manner as disclosed in United States Patent Application, Publication No. 2012-0149916.
The component (D) may contain a nitrogen-containing organic compound component that does not correspond to the component (D0) and the component (D1), which are described above.
The component (D2) is not particularly limited, and any one from the known compounds may be used. Among the above, aliphatic amines are preferable, and among the aliphatic amines, in particular, a secondary aliphatic amine or a tertiary aliphatic amine is more preferable.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include amines in which at least one hydrogen atom of ammonia NH3 has been substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkyl amines or alkyl alcohol amines), and cyclic amines.
Specific examples of the alkyl amine and the alkyl alcohol amine include monoalkyl amines such as n-hexyl amine, n-heptyl amine, n-octyl amine, n-nonyl amine, and n-decyl amine; dialkyl amines such as diethyl amine, di-n-propyl amine, di-n-heptyl amine, di-n-octyl amine, and dicyclohexyl amine; trialkyl amines such as trimethyl amine, triethyl amine, tri-n-propyl amine, tri-n-butyl amine, tri-n-hexyl amine, tri-n-pentyl amine, tri-n-heptyl amine, tri-n-octyl amine, tri-n-nonyl amine, tri-n-decyl amine, and tri-n-dodecyl amine; 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, trialkyl amines of 5 to 10 carbon atoms are preferable, and tri-n-pentyl amine and tri-n-octyl amine are 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 (aliphatic monocyclic amine), or a polycyclic compound (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 triethanol amine triacetate, and triethanol amine 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, N-tert-butoxycarbonylpyrrolidine, and 2,6-di-tert-butylpyridine.
The component (D2) may be used alone or in a combination of two or more kinds thereof.
The content of the component (D2) is preferably 5 parts by mass or less, more preferably in a range of 0 to 5 parts by mass, and still more preferably in a range of 0 to 3 parts by mass with respect to 100 parts by mass of the component (A).
In a case where the content of the component (D2) is within the preferred range, excellent lithography characteristics and an excellent resist pattern shape are easily obtained.
It is preferable that the resist composition according to the present embodiment not contain the component (D2).
The resist composition according to the present embodiment may further contain other components in addition to the component (A), the component (B), and the component (D) described above. Examples of the other components include a component (E), a component (F), and a component (S), described below.
<<At Least One Compound (E) Selected from the Group Consisting of Organic Carboxylic Acid, Phosphorus Oxo Acid, and Derivatives Thereof>>
For the 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 may contain, as an optional component, 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.
Specific examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, and among them, salicylic acid is preferable.
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 phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of the phosphonic acid derivative include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate.
Examples of the phosphinic acid derivative include phosphinic acid esters and phenylphosphinic acid.
In the resist composition according to the present embodiment, one kind of the component (E) may be used alone, or two or more kinds thereof may be used in combination.
In a case where the resist composition contains the component (E), the content of the component (E) is preferably in a range of 0.01 to 5 parts by mass and more preferably in a range of 0.05 to 3 parts by mass with respect to 100 parts by mass of the component (A). Within the above range, the lithography characteristics are further improved.
The resist composition according to the present embodiment may contain a fluorine additive component (hereinafter, referred to as a “component (F)”) as a hydrophobic resin. The component (F) is used to impart water repellency to the resist film and used as a resin different from the component (A), whereby the lithography characteristics can be improved. 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 (a homopolymer) consisting only of a constitutional unit (f1) represented by General Formula (f1-1); a copolymer of the constitutional unit (f1) and the constitutional unit (a1); a copolymer of the constitutional unit (f1), a constitutional unit derived from acrylic acid or methacrylic acid, and the constitutional unit (a1), and more preferably a copolymer of the constitutional unit (f1) and the 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, and more preferably a constitutional unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate.
[In the formula, R has the same definition as described above, Rf102 and Rf103 each independently represents 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 as or different from each other. nf1 represents an integer in a range of 0 to 5, and Rf101 represents an organic group having 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), a fluorine atom is preferable as the halogen atom as Rf102 and Rf103. Examples of the alkyl group having 1 to 5 carbon atoms as Rf102 and Rf103 include the same groups as those for the alkyl group having 1 to 5 carbon atoms as R. Among the examples, 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 groups in which some or all hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. The halogen atom is preferably a fluorine atom. Among these, Rf102 and Rf103 are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and still more preferably a hydrogen atom.
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 1 or 2.
In General Formula (f1-1), Rf101 represents an organic group having a fluorine atom and preferably a hydrocarbon group having a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, and it preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and particularly preferably has 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 the examples, Rf101 represents more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms and particularly preferably a trifluoromethyl group, —CH2—CF3, —CH2—CF2—CF3, —CH(CF3)2, —CH2—CH2—CF3, or —CH2—CH2—CF2—CF2—CF2—CF3.
The weight-average molecular weight (Mw) (in terms of 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, the resist composition exhibits sufficient solubility in a resist solvent to be used as a resist. On the other hand, in a case where the weight-average molecular weight 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) in the resist composition is preferably in a range of 0.5 to 10 parts by mass and more preferably in a range of 1 to 10 parts by mass with respect to 100 parts by mass of the component (A).
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 an optional organic solvent can be appropriately selected from those which are conventionally known in the related art as solvents for a chemical amplification-type resist composition and then used. Examples of the component (S) include lactones such as y-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.
In addition, 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, but 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.
In addition, 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 appropriately 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 the 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 consisting of a porous polyimide membrane, a filter consisting of a porous polyamideimide membrane, or a filter consisting 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 contains a compound (B0) having a molar absorption coefficient of 50,000 mol·L·cm−1 or less at an exposure wavelength of 193 nm and a compound (D0) represented by General Formula (d0).
Since the compound (B0) has a molar absorption coefficient of 50,000 mol−1·L·cm−1 or less at an exposure wavelength of 193 nm, the transmittance of light (typically, an ArF excimer laser) of the resist film that is formed from the resist composition containing the compound (B0) is improved, and a reaction by which acid is generated from the compound (B0) in the resist film is likely to be uniformly carried out.
On the other hand, since the compound (B0) has a low molar absorption coefficient as compared with the acid generators in the related art, a reaction by which the cation moiety of the acid generator is decomposed upon exposure tends to decrease.
Since the compound (D0) has a quenching ability in unexposed portions of the resist film, while the anion moiety thereof is a sulfonate anion having a divalent linking group containing an oxygen atom, the divalent linking group being a polar group, a relatively strong acid is generated in exposed portions of the resist film, and it is possible to promote the action on the component (A), where the action is carried out by the strong acid that is generated from the compound (B0).
In a case where the compound (B0) is combined with the compound (D0), it is possible to improve the sensitivity while uniformly carrying out a reaction by which acid is generated from the compound (B0) in the resist film.
As described above, according to the resist composition according to the present embodiment, it is possible to form a resist composition which achieves higher sensitivity and makes it possible to form a resist pattern having a good roughness reduction property and a good pattern shape.
A method for forming a resist pattern according to the second aspect according to the present invention is a method including a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention described above, 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 for forming a resist pattern include a method for 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 in a range 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 on the mask by using an exposure apparatus such as an electron beam lithography apparatus or an ArF 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 conduct 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 specifically limited and a known support in the related art can be used. For example, substrates for electronic components, and such substrates 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.
In addition, as the support, any support having the above-described substrate 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 (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 conduct patterning of the lower-layer organic film. This method is considered as being capable of forning a pattern with 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 basically 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, and a soft X-ray. Since the resist composition is highly useful for a KrF excimer laser, an ArF excimer laser, EB, or EUV, and the resist composition contains a compound (B0) having a molar absorption coefficient of 50,000 mol−1·L·cm−1 or less at an exposure wavelength of 193 nm, it is highly useful for an ArF excimer laser.
That is, in the step of exposing the resist film, it is preferable to irradiate the resist film with an ArF excimer laser.
The exposure method 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 lithography; however, liquid immersion lithography is more preferable.
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.
As the liquid immersion medium, 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 is preferable. The refractive index of the solvent is not particularly limited as long as it is in the above-described range.
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 liquid include a liquid containing a fluorine-based compound such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, or C5H3F7 as a main component, and a liquid with a boiling point of 70° C. to 180° C. is preferable and a liquid with a boiling point of 80° C. to 160° C. is more preferable. 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 preferably carried out by a simple method.
The fluorine-based inert liquid is preferably a perfluoroalkyl compound in which all of the hydrogen atoms of the alkyl group are substituted with a fluorine atom. Specific examples of these perfluoroalkyl compounds include perfluoroalkyl ether compounds and perfluoroalkyl amine compounds.
Further, specifically, examples of the perfluoroalkyl ether compound include perfluoro(2-butyl-tetrahydrofuran) (boiling point: 102° C.), and examples of the perfluoroalkyl amine compound include perfluorotributyl amine (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 tetramethylammonium hydroxide (TMAH) of 0.1% to 10% by mass.
As the organic solvent contained in the organic developing solution which is used for a developing treatment in a solvent developing process, any one of the conventionally known organic solvents capable of dissolving the component (A) (component (A) prior to exposure) 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, an ether-based solvent, and a hydrocarbon-based solvent.
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. The term “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 functional group that characterizes a solvent. 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 a 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 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, propylene carbonate, 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. As the surfactant, a non-ionic surfactant is preferable, and a non-ionic fluorine-based surfactant or a non-ionic silicon-based surfactant is more preferable.
In a case where a surfactant is blended, the blending amount thereof 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 being rotated at a constant rate while being scanned 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, for example, 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 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 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 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. In addition, 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 as those described above, the surfactant is preferably a non-ionic surfactant and more preferably a non-ionic fluorine-based surfactant or a non-ionic silicon-based surfactant.
In a case where a surfactant is blended, the blending amount thereof 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 using a rinse liquid (washing treatment) can be carried out by a conventionally known rinse method. Examples of the rinse treatment method include a method in which the rinse liquid is continuously ejected and applied onto the support while rotating it at a constant rate (rotational coating method), a method in which the support is immersed in the rinse liquid for a predetermined time (dip method), and a method in which the rinse liquid is sprayed onto the surface of the support (spray method).
According to the method for forming a resist pattern according to the present embodiment described above, since the resist composition described above is used, it is possible to form a resist composition which achieves higher sensitivity and makes it possible to form a resist pattern having a good roughness reduction property and a good pattern shape.
Various materials that are used in the resist composition according to the above-described embodiment and the method for forming a pattern according to the above-described embodiment (for example, a resist solvent, a developing solution, a rinse liquid, a composition for forming an antireflection film, and a composition for forming a top coat) preferably do not contain impurities such as a metal, a metal salt containing halogen, an acid, an alkali, and a component containing a sulfur atom or phosphorus atom. Here, examples of the impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, and salts thereof. The content of the impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, still more preferably 100 parts per trillion (ppt) or less, and particularly preferably 10 ppt or less, where it is most preferable that the impurities be substantially negligible (below the detection limit of the measuring device).
Hereinafter, the present invention will be described in more detail based on Examples; however, the present invention is not limited to these Examples.
Each of polymeric compounds (A-1) to (A-4) used in present Examples was obtained by carrying out radical polymerization using monomers from which constitutional units constituting each of the polymeric compounds are derived, at a predetermined molar ratio.
The weight-average molecular weight (Mw) and the molecular weight polydispersity (Mw/Mn) of each of the obtained polymeric compounds were determined according to the GPC measurement (in terms of the standard polystyrene equivalent value).
In addition, the copolymerization composition ratio (the proportion (molar ratio) of each constitutional unit in the structural formula) of each of the obtained polymeric compounds was determined from the carbon 13 nuclear magnetic resonance spectrum (600 MHz_13C-NMR).
Polymeric compound (A-1): Weight-average molecular weight (Mw): 7,100, molecular weight polydispersity (Mw/Mn): 1.58, 1/m=50/50.
Polymeric compound (A-2): Weight-average molecular weight (Mw): 7,000, molecular weight polydispersity (Mw/Mn): 1.60, 1/m=50/50.
Polymeric compound (A-3): Weight-average molecular weight (Mw): 7,300, molecular weight polydispersity (Mw/Mn): 1.57, 1/m=50/50.
Polymeric compound (A-4): Weight-average molecular weight (Mw): 6,800, molecular weight polydispersity (Mw/Mn): 1.63, 1/m=50/50.
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 [ ] indicate blending amounts (in terms of parts by mass).
The molar absorption coefficient of the component (B) was obtained by measuring the absorbance of the component (B) at a wavelength of 193 nm with a spectrophotometer and carrying out a calculation using the Lambert-Beer law.
Specifically, the component (B) was dissolved in acetonitrile, this solution was placed in a cell having an optical path length of 10 mm, the UV spectrum was measured with a spectrophotometer (UV-3600, manufactured by Shimadzu Corporation), and the absorbance at a wavelength of 193 nm was acquired. Next, the molar absorption coefficient ε(mol−1·L·cm−1) was calculated from the obtained absorbance and the solution concentration using the Lambert-Beer law.
The molar absorption coefficient ε(mol−1·L·cm−1) calculated according to the method described above is also shown below each of the following chemical formulae.
An organic antireflection film composition (product name: ARC29A, manufactured by Brewer Science Inc.) was applied onto a 12-inch silicon wafer using a spinner and sintered and dried on a hot plate at 205° C. for 60 seconds to form an organic antireflection film having a thickness of 98 nm.
The resist composition of each Example was applied onto the antireflection film using a spinner, and a pre-baking (PAB) treatment was carried out at 110° C. for 60 seconds on a hot plate, followed by drying to form a resist film having a film thickness of 90 nm.
Next, the resist film was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (halftone: 6%) using an ArF exposure apparatus for liquid immersion XT 1900Gi [manufactured by ASML; numerical aperture (NA)=1.35, Dipole 90X, Sigma (in/out=0.80/0.97) TE-pol, liquid immersion medium: ultrapure water]. Then, PEB treatment was carried out at 90° C. for 60 seconds.
Next, alkali development was carried out with a 2.38% by mass TMAH aqueous solution (product name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23° C. for 15 seconds, and then water rinsing was carried out for 15 seconds using pure water, followed by shake-off drying.
As a result, a line-and-space pattern (hereinafter referred to as an LS pattern) having a line size of 40 nm and a pitch of 80 nm (mask size: 40 nm) was formed in all of Examples.
According to <Resist pattern formation> described above, an optimum exposure amount Eop (mJ/cm2) for forming the LS pattern having the target size was determined. The results are shown in Table 3 as “Eop (mJ/cm2)”.
3σ of the LS pattern formed in <Resist pattern formation> described above, which is a scale indicating LWR, was determined. The results are shown in Table 3 “LWR (nm)”.
“3σ” indicates a triple value (3σ) (unit: nm) of the standard deviation (σ) determined from measurement results obtained by measuring 400 line positions in the longitudinal direction of the line with a critical dimension scanning electron microscope (SEM, acceleration voltage: 500 V, product name: CG5000, manufactured by Hitachi High-Tech Corporation).
The smaller the value of 3σ, the smaller the roughness in the line side wall, which means an LS pattern having a more uniform width was obtained.
The cross-sectional shape of the LS pattern which had been formed in <Resist pattern formation> described above was observed with a critical dimension SEM (scanning electron microscope, acceleration voltage: 10 kV, product name: SU-8000, manufactured by Hitachi High-Tech Corporation) to measure a line width Lb in the middle of the resist pattern in a height direction and a line width La in the upper part of the resist pattern, and the value of La/Lb was calculated. These results are shown in Table 3 as “Pattern shape”. It should be noted that the closer the value to 1, the more uniform the line width of the resist pattern in the height direction, which means that a good pattern had been formed.
As shown in Table 3, it was confirmed that it is possible to form a resist pattern that has good sensitivity, a good roughness reducing property, and a good pattern shape as compared with the resist compositions of Examples as compared with the resist compositions of Comparative Examples.
From the comparison among Examples 1 and 5 to 10, among the resist compositions of Examples, the resist compositions of Examples 1, 5, 6, and 8 to 10, which contained each of acid generators consisting of compounds represented by Chemical Formulae (B0-1) to (B0-3) and (B0-5) to (B0-7) having a molar absorption extinction coefficient of 36,500 to 40,380 mol−1·L·cm−1, can further achieve all of the sensitivity, the roughness reducing property, and the pattern shape in the resist pattern formation as compared with the resist composition of Example 7, which contained an acid generator consisting of the compound represented by Chemical Formula (B0-4) having a molar absorption extinction coefficient of 42,989 mol−1·L·cm−1.
The preferred Examples of the present invention have been described above; however, the present invention is not limited to these Examples. Additions, omissions, substitutions, and other modifications of the configuration can be made without departing from the spirit of the present invention. Accordingly, the present 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 |
|---|---|---|---|
| 2021-180983 | Nov 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/040894 | 11/1/2022 | WO |
