Patent Application
20240248398
The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition, a method for manufacturing the actinic ray-sensitive or radiation-sensitive resin composition, an actinic ray-sensitive or radiation-sensitive film, a pattern forming method, a method for manufacturing an electronic device, a resin, and a method for manufacturing the resin. More particularly, the invention relates to an actinic ray-sensitive or radiation-sensitive resin composition that is preferably used for ultramicrolithography processes applicable to processes for manufacturing VLSI (very large scale integration) circuits and high-capacity microchips, to processes for producing molds for nanoimprinting, to processes for manufacturing high-density information recording mediums, and to other processes and also applicable to other photofabrication processes and also relates to a method for manufacturing the actinic ray-sensitive or radiation-sensitive resin composition, an actinic ray-sensitive or radiation-sensitive film, a pattern forming method, a method for manufacturing an electronic device, and a resin.
Conventional manufacturing processes for semiconductor devices such as ICs (Integrated Circuits) or LSI circuits involve lithographic microfabrication using a photoresist composition. In recent years, the degree of integration of integrated circuits has increased, and there is a growing demand for ultra-fine pattern formation in the submicron or quarter-micron range. Accordingly, the wavelength of exposure light tends to be shortened. Specifically, the g-line is replaced by the i-line and then by KrF excimer laser light. At present, exposure devices using an ArF excimer laser with a wavelength of 193 nm as the light source are being developed. In addition, techniques for further increasing resolving power are under development. Specifically, the so-called immersion method is under development, in which the space between a projection lens and a specimen is filled with a high-refractive index liquid (hereinafter referred to as “immersion liquid”).
At present, in addition to the use of excimer laser light, lithography using electron beams (EB), X-rays, extreme ultraviolet rays (EUV), etc. is being developed. This leads to the development of chemical amplification resist compositions that are effectively sensitive to various types of radiation and exhibit high sensitivity and resolution.
For example, WO2020/158417A describes an actinic ray-sensitive or radiation-sensitive resin composition that contains a resin including a repeating unit having an acid-decomposable group and further including a fluorine atom.
JP2010-222279A describes a polymerizable compound having a pentafluorosulfanyl group and a polymer thereof.
In recent years, the demands on the performance of resist compositions have continued to increase as due to the reduction in the size of patterns to be formed etc. In particular, there is a need for a resist composition that causes fewer defects and provides good line width roughness (LWR) performance. The LWR performance refers to the ability to reduce the LWR of a pattern.
The actinic ray-sensitive or radiation-sensitive resin composition described in WO2020/158417A provides good resolution and LWR performance. However, there is no description of defects.
JP2010-222279A does not describe any resist compositions.
It is an object of the invention to provide an actinic ray-sensitive or radiation-sensitive resin composition that causes fewer defects and provides good LWR performance. It is another object of the invention to provide a method for manufacturing the actinic ray-sensitive or radiation-sensitive resin composition, to provide an actinic ray-sensitive or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device that use the actinic ray-sensitive or radiation-sensitive resin composition, and to provide a resin that can be used for the actinic ray-sensitive or radiation-sensitive resin composition.
The inventors have found that the above objects can be achieved by the following.
[1] An actinic ray-sensitive or radiation-sensitive resin composition including: a resin (A) having a pentafluorosulfanyl group; and a solvent.
[2] The actinic ray-sensitive or radiation-sensitive resin composition according to [1], further including a compound that generates an acid upon irradiation with actinic rays or radiation.
[3] The actinic ray-sensitive or radiation-sensitive resin composition according to [1] or [2], wherein the resin (A) includes a repeating unit having an acid-decomposable group.
[4] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [3], wherein the resin (A) includes a repeating unit having at least one selected from the group consisting of lactone groups and cyclic carbonate groups.
[5] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [4], wherein the resin (A) includes a repeating unit having a phenolic hydroxy group.
[6] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [5], wherein the resin (A) includes a repeating unit represented by the following general formula (1):
In general formula (1),
Xa1 represents a hydrogen atom, a halogen atom, a hydroxy group, or an organic group.
Rx1 to Rx3 each independently represent a hydrocarbon group.
Two selected from the group consisting of Rx1 to Rx3 may be bonded together to form a ring.
[7] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [6], wherein the resin (A) includes a repeating unit formed by polymerization of a polymerizable group in a polymerizable compound represented by any of the following general formulas (2), (3), and (4):
In general formula (2),
Z1 represent a group having the polymerizable group.
E1 represents a single bond or a linking group.
Xa represents a halogen atom, a hydroxy group, or an organic group. When a plurality of Xa's are present, the plurality of Xa's may be the same or different.
m1 represents an integer of 1 or more and (5+2k) or less.
m2 represents an integer of 0 or more and (5+2k−m1) or less.
k represents an integer of 0 or more.
*'s each represent a direct bond bonded to an aromatic hydrocarbon shown in general formula (2).
In general formula (3),
Z1 represents a group having the polymerizable group.
E1 represents a single bond or a linking group.
W1 represents a group having a lactone structure.
m3 represents an integer of 1 or more.
In general formula (4),
Z1 represents a group having the polymerizable group.
E1 represents a single bond or a linking group.
Rx4 and Rx5 each independently represent a hydrogen atom or an organic group.
Rx4 and Rx5 may be bonded together to form a ring.
[8] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [7], further including, in addition to the resin (A), a resin different from the resin (A).
[9] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [8], wherein the content of the resin (A) with respect to the total mass of solids in the actinic ray-sensitive or radiation-sensitive resin composition is 10.0% by mass or more.
[10] A method for manufacturing the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [9], the method including the step of adding a solution of the resin (A) to a poor solvent including an organic solvent (Y) to cause the resin (A) to precipitate.
[11] The method for manufacturing the actinic ray-sensitive or radiation-sensitive resin composition according to [10], wherein the organic solvent (Y) has a C log P value of 1.4 or more.
[12] An actinic ray-sensitive or radiation-sensitive film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [9].
[13] A pattern forming method including the steps of:
[14] A method for manufacturing an electronic device, the method including the pattern forming method according to [13].
[15] A resin including a repeating unit having a pentafluorosulfanyl group and a repeating unit having an acid-decomposable group.
[16] The resin according to [15], further including at least one selected from the group consisting of a repeating unit having a lactone group, a repeating unit having a cyclic carbonate group, and a repeating unit having a phenolic hydroxy group.
[17] A method for manufacturing the resin according to [15] or [16], the method including the step of adding a solution of the resin to a poor solvent including an organic solvent (Y) to cause the resin to precipitate.
[18] The method for manufacturing the resin according to [17], wherein the organic solvent (Y) has a C log P value of 1.4 or more.
The present invention can provide an actinic ray-sensitive or radiation-sensitive resin composition that causes fewer defects and provides good LWR performance. The invention can also provide a method for manufacturing the actinic ray-sensitive or radiation-sensitive resin composition, provide an actinic ray-sensitive or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device that use the actinic ray-sensitive or radiation-sensitive resin composition, and provide a resin that can be used for the actinic ray-sensitive or radiation-sensitive resin composition.
The present invention will next be described in detail.
Description of structural requirements described below may be made on the basis of representative embodiments of the present invention. However, the invention is not limited to theses embodiments.
As for notations of groups (atomic groups) in the present specification, a notation that is not specified as substituted and unsubstituted is intended to encompass groups having no substituent and groups having a substituent, so long as the notation does not depart from the spirit of the invention. For example, an “alkyl group” is intended to encompass not only an alkyl group having no substituent (an unsubstituted alkyl group) but also an alkyl group having a substituent (a substituted alkyl group).
Preferably, the substituent is a monovalent substituent, unless otherwise specified.
In the present specification, when the phrase “optionally having a substituent” or the phrase “may have a substituent” appears, no particular limitation is imposed on the type of substituent, the position of the substituent, and the number of substituents. The number of substituents may be, for example, 1, 2, 3, or more. Examples of the substituent include monovalent nonmetallic atomic groups except for a hydrogen atom, and the substituent can be selected from, for example, the following substituents T.
Examples of the substituents T include: halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; alkoxy groups such as a methoxy group, an ethoxy group, and a tert-butoxy group; aryloxy groups such as a phenoxy group and a p-tolyloxy group; alkoxycarbonyl groups such as a methoxycarbonyl group, a butoxycarbonyl group, and a phenoxycarbonyl group; acyloxy groups such as an acetoxy group, a propionyloxy group, and a benzoyloxy group; acyl groups such as an acetyl group, a benzoyl group, an isobutyryl group, an acryloyl group, a methacryloyl group, and a methoxalyl group; alkylsulfanyl groups such as a methylsulfanyl group and a tert-butylsulfanyl group; arylsulfanyl groups such as a phenylsulfanyl group and a p-tolylsulfanyl group; alkyl groups; cycloalkyl groups; aryl groups; heteroaryl groups; a hydroxy group; a carboxy group; a formyl group; a sulfo group; a cyano group; alkylaminocarbonyl groups; arylaminocarbonyl groups; sulfonamido groups; silyl groups; an amino group; monoalkylamino groups; dialkylamino groups; arylamino groups; a nitro group; a formyl group; and combinations thereof.
In the present specification, the “organic group” is a group including at least one carbon atom.
In the present specification, “actinic rays” or “radiation” means, for example, an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser light, extreme ultraviolet light (EUV light), X-rays, an electron beam (EB), etc.
In the present specification, “light” means actinic rays or radiation.
In the present specification, “exposure to light” is intended to encompass not only exposure to an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser light, X-rays, EUV light, etc. but also image drawing using an electron beam or a particle beam such as an ion beam.
In the present specification, “to” is used to mean that numerical values before and after the “to” are used as the lower limit and the upper limit.
In the present specification, no limitation is imposed on the bonding direction of a divalent group, unless otherwise specified. For example, when Y in a compound represented by formula “X—Y—Z” is —COO—, Y may be —CO—O— or may be —O—CO—. This compound may be “X—CO—O—Z” or may be “X—O—CO—Z.”
In the present specification, (meth)acrylate is intended to refer to acrylate and methacrylate, and (meth)acrylic is intended to refer to acrylic and methacrylic.
In the present specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (hereinafter may be referred to also as the “molecular weight distribution”) (Mw/Mn) of a compound are defined as polystyrene-equivalent values determined by GPC (Gel Permeation Chromatography) measurement (solvent: tetrahydrofuran, flow rate (injection amount of a sample): 10 μL, columns: TSK gel Multipore HXL-M manufactured by TOSOH Corporation, column temperature: 40° C., flow velocity: 1.0 mL/minute, detector: differential refractive index detector) using a GPC apparatus (HLC-8120GPC manufactured by TOSOH Corporation).
In the present specification, the acid dissociation constant (pKa) is the pKa in an aqueous solution and is specifically a value determined by computation using the following software package 1 based on a Hammett substituent constant and a database of known literature values. All pKa values in the present specification are values determined by computation using this software package.
Software package 1: Advanced Chemistry Development (ACD/Labs) Software V 8.14 for Solaris (1994-2007 ACD/Labs).
The pKa can also be determined by a molecular orbital calculation method. In one specific example of this method, H+ dissociation free energy in an aqueous solution is computed based on a thermodynamic cycle to compute the pKa. As for the method for computing the H+ dissociation free energy, the density functional theory (DFT), for example, can be used for the computation. Various other methods have been reported in literature etc., but the computation method is not limited thereto. There are a plurality of software applications capable of performing the DFT, and one example is Gaussian 16.
In the present specification, the pKa is a value determined by computation using the software package 1 based on the Hammett substituent constant and the database of known literature values as described above. When the pKa cannot be computed using this method, a value obtained using Gaussian 16 based on the DFT (density functional theory) is used.
In the present specification, the pKa is a “value in an aqueous solution” as described above. When the pKa in an aqueous solution cannot be computed, the “pKa in a dimethyl sulfoxide (DMSO) solution” is used.
The actinic ray-sensitive or radiation-sensitive resin composition of the invention includes a resin (A) having a pentafluorosulfanyl group (which may be referred to simply as a “resin (A)”) and a solvent.
The actinic ray-sensitive or radiation-sensitive resin composition of the invention is typically a resist composition. The actinic ray-sensitive or radiation-sensitive resin composition of the invention is hereinafter referred to also as a “resist composition.”
The resist composition may be a positive-type resist composition or a negative-type resist composition. The resist composition may be a resist composition for alkali development and may be a resist composition for organic solvent development.
The resist composition is preferably a chemical amplification-type resist composition.
The actinic ray-sensitive or radiation-sensitive resin composition of the invention causes fewer defects and provides good LWR performance. The inventors infer that the reason for this is as follows.
The bulky pentafluorosulfanyl group having a specific configuration can effectively reduce diffusion of acid in the resist film, and this may be one reason for the good LWR performance. Moreover, the pentafluorosulfanyl group can highly effectively absorb EBs and EUV light, and the photon absorption efficiency of the resist film is thereby improved. This may be another factor in the improvement of the LWR performance.
When the resin (A) having a pentafluorosulfanyl group is used, the dissolution contrast between unexposed and exposed portions of the resist film in the developer increases, and this may reduce the occurrence of defects. The mechanism of the improvement in dissolution contrast may be as follows.
The resin (A) having a pentafluorosulfanyl group is very difficult to dissolve in an alkali developer, and therefore the solubility of the unexposed portions in the alkali developer is low. However, the pentafluorosulfanyl group increases the solubility of an acid group generated by light exposure in the alkali developer (the reason for this is unclear but may be that the acid group generated by light exposure and the pentafluorosulfanyl group interact with each other in some manner). This increases the dissolution contrast between the unexposed and exposed portions.
The resin (A) having a pentafluorosulfanyl group can very easily dissolve in an organic solvent developer, and therefore the solubility of the unexposed portions in the organic solvent developer is high. However, the pentafluorosulfanyl group decreases the solubility of the acid group generated by light exposure in the organic solvent developer (the reason for this is unclear but may be that the acid group generated by light exposure and the pentafluorosulfanyl group interact with each other in some manner). This increases the dissolution contrast between the unexposed and exposed portions.
The resist composition includes the resin (A) having a pentafluorosulfanyl group (—SF5).
The resin (A) is typically a polymerized material and is preferably a polymerized material having a molecular weight of 100 or more. The resin (A) may be an oligomer or may be a polymer.
No particular limitation is imposed on the structure of the resin (A) so long as it has at least one pentafluorosulfanyl group.
The resin (A) may be, for example, a resin including a repeating unit having a pentafluorosulfanyl group and a repeating unit having an acid-decomposable group or may be a resin further including at least one selected from the group consisting of a repeating unit having a lactone group, a repeating unit having a cyclic carbonate group, and a repeating unit having a phenolic hydroxy group. The resin (A) may be a resin other than the above resins.
The resin (A) includes preferably an acid-decomposable group (a group that is decomposed by the action of an acid and thereby increased in polarity) and includes more preferably a repeating unit having an acid-decomposable group.
When the resin (A) includes a repeating unit having an acid-decomposable group, the resin (A) is an acid-decomposable resin.
The repeating unit having an acid-decomposable group may have a pentafluorosulfanyl group or may not have a pentafluorosulfanyl group.
Preferably, the acid-decomposable group is a group that is decomposed by the action of an acid to generate a polar group.
Preferably, the acid-decomposable group has a structure in which the polar group is protected by a leaving group that leaves by the action of an acid. Specifically, it is preferable that the resin (A) has a repeating unit having a group that is decomposed by the action of an acid to generate a polar group. The resin having this repeating unit is increased in polarity by the action of an acid. The degree of solubility in an alkali developer thereby increases, and the degree of solubility in an organic solvent decreases.
The polar group is preferably an alkali-soluble group, and examples thereof include: acidic groups such as a carboxy group, phenolic hydroxy groups, fluorinated alcohol groups, sulfonic acid groups, phosphoric acid groups, sulfonamido groups, sulfonylimido groups, (alkylsulfonyl)(alkylcarbonyl)methylene groups, (alkylsulfonyl)(alkylcarbonyl)imido groups, bis(alkylcarbonyl)methylene groups, bis(alkylcarbonyl)imido groups, bis(alkylsulfonyl)methylene groups, bis(alkylsulfonyl)imido groups, tris(alkylcarbonyl)methylene groups, and tris(alkylsulfonyl)methylene groups; and alcoholic hydroxyl groups.
The polar group is preferably a carboxy group, a phenolic hydroxy group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group.
Examples of the leaving group that leaves by the action of an acid include groups represented by formulas (Y1) to (Y4).
In formulas (Y1) and (Y2), Rx1 to Rx3 each independently represent a hydrocarbon group and each independently represent preferably an alkyl group (linear or branched alkyl group), a cycloalkyl group (monocyclic or polycyclic cycloalkyl group), an alkenyl group (linear or branched alkenyl group), or an aryl group (monocyclic or polycyclic aryl group). When all of Rx1 to Rx3 are alkyl groups (linear or branched alkyl groups), it is preferable that at least two selected from the group consisting of Rx1 to Rx3 are each a methyl group.
In particular, it is preferable that Rx1 to Rx3 each independently represent a linear or branched alkyl group, and it is more preferable that Rx1 to Rx3 each independently represent a linear alkyl group.
Two selected from the group consisting of Rx1 to Rx3 may be bonded together to form a ring (which may be a monocyclic ring or a polycyclic ring).
The alkyl group represented by each of Rx1 to Rx3 is preferably an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, or a t-butyl group.
The cycloalkyl group represented by each of Rx1 to Rx3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. In the above cycloalkyl groups, for example, one of the methylene groups forming the ring may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a group including a heteroatom such as a carbonyl group, or a vinylidene group. In the above cycloalkyl groups, at least one ethylene group included in the cycloalkane ring may be replaced with a vinylene group.
The aryl group represented by each of Rx1 to Rx3 is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
The alkenyl group represented by each of Rx1 to Rx3 is preferably a vinyl group.
The ring formed by bonding two selected from the group consisting of Rx1 to Rx3 is preferably a cycloalkyl group. The cycloalkyl group formed by bonding two selected from the group consisting of Rx1 to Rx3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group and is more preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms.
For example, one methylene group included in the ring in the cycloalkyl group formed by bonding two selected from the group consisting of Rx1 to Rx3 may be replaced with a heteroatom such as an oxygen atom, a group including a heteroatom such as a carbonyl group, or a vinylidene group. In any of these cycloalkyl groups, at least one ethylene group included in the cycloalkane ring may be replaced with a vinylene group.
In the group represented by formula (Y1) or formula (Y2), it is preferable that, for example, Rx1 is a methyl group or an ethyl group and that Rx2 and Rx3 are bonded together to form the cycloalkyl group described above.
When the resist composition is, for example, a resist composition for EUV exposure, it is also preferable that the alkyl, cycloalkyl, alkenyl, and aryl groups represented by Rx1 to Rx3 and the ring formed by bonding two selected from the group consisting of Rx1 to Rx3 each further have a fluorine atom or an iodine atom as a substituent.
In formula (Y3), R36 to R38 each independently represent a hydrogen atom or a monovalent organic group. R3 and R38 may be bonded together to form a ring. Examples of the monovalent organic group include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, and alkenyl groups. It is also preferable that R36 is a hydrogen atom.
The alkyl, cycloalkyl, aryl, and aralkyl groups described above may each include a heteroatom such as an oxygen atom and/or a group including a heteroatom such as a carbonyl group. For example, in the alkyl, cycloalkyl, aryl, and aralkyl groups described above, at least one methylene group may be replaced with a heteroatom such as an oxygen atom and/or a group including a heteroatom such as a carbonyl group.
R38 may be bonded to another substituent included in the main chain of the repeating unit to form a ring. The group formed by bonding R38 and another substituent included in the main chain of the repeating unit is preferably an alkylene group such as a methylene group.
When the resist composition is, for example, a resist composition for EUV exposure, it is also preferable that the monovalent organic groups represented by R36 to R38 and the group formed by bonding R37 and R38 together each further have a fluorine atom or an iodine atom as a substituent.
Formula (Y3) is preferably a group represented by the following formula (Y3-1).
L1 and L2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group formed by combining any of them (for example, a group formed by combining an alkyl group and an aryl group).
M represents a single bond or a divalent linking group.
Q represents an alkyl group optionally including a heteroatom, a cycloalkyl group optionally including a heteroatom, an aryl group optionally including a heteroatom, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group, or a group formed by combining any of them (for example, a group formed by combining an alkyl group and a cycloalkyl group).
In the alkyl and cycloalkyl groups, for example, one methylene group may be replaced with a heteroatom such as an oxygen atom or a group including a heteroatom such as a carbonyl group.
It is preferable that one of L1 or L2 is a hydrogen atom and that the other is an alkyl group, a cycloalkyl group, an aryl group, or a group formed by combining an alkylene group and an aryl group.
At least two selected from the group consisting of Q, M, and L1 may be bonded together to form a ring (preferably a 5-membered or 6-membered ring).
From the viewpoint of obtaining a finer pattern, L2 is preferably a secondary or tertiary alkyl group and more preferably a tertiary alkyl group. Examples of the secondary alkyl group include an isopropyl group, a cyclohexyl group, and a norbornyl group, and examples of the tertiary alkyl group include a tert-butyl group and an adamantane group. In these modes, since Tg (glass transition temperature) and activation energy are high, high film hardness is obtained, and the occurrence of fogging can be reduced.
When the resist composition is, for example, a resist composition for EUV exposure, it is also preferable that the alkyl, cycloalkyl, and aryl groups represented by L1 and L2 and a group formed by combining any of these groups each further have a fluorine atom or an iodine atom as a substituent. It is also preferable that the alkyl, cycloalkyl, aryl, and aralkyl groups each include a heteroatom such as an oxygen atom other than a fluorine atom and an iodine atom (i.e., in the alkyl, cycloalkyl, aryl, and aralkyl groups, for example, one methylene group is replaced with a heteroatom such as an oxygen atom or a group including a heteroatom such as a carbonyl group).
When the resist composition is, for example, a resist composition for EUV exposure, it is also preferable that, in the alkyl group optionally including a heteroatom, the cycloalkyl group optionally including a heteroatom, the aryl group optionally including a heteroatom, the amino group, the ammonium group, the mercapto group, the cyano group, and the aldehyde group that are represented by Q and a combination of any of these groups, the heteroatom is one selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom.
In formula (Y4), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may be bonded together to form a non-aromatic ring. Ar is preferably an aryl group.
When the resist composition is, for example, a resist composition for EUV exposure, it is also preferable that the aromatic ring group represented by Ar and the alkyl, cycloalkyl, or aryl group represented by Rn each have a fluorine atom or an iodine atom as substituents.
When, in the leaving group protecting the polar group, a non-aromatic ring is bonded directly to the polar group (or its residue), it is also preferable that a ring member atom adjacent to the ring member atom bonded directly to the polar group (or its residue) in the non-aromatic ring does not have a halogen atom such as a fluorine atom as a substituent, because the repeating unit can have good acid-decomposability.
The leaving group that leaves by the action of an acid may also be a 2-cyclopentenyl group having a substituent (e.g., an alkyl group) such as a 3-methyl-2-cyclopentenyl group or a cyclohexyl group having a substituent (e.g., an alkyl group) such as a 1,1,4,4-tetramethylcyclohexyl group.
Preferably, the resin (A) includes at least one selected from the group consisting of a group formed by replacing a hydrogen atom in a carboxy group with an acid-decomposable group, a group formed by replacing a hydrogen atom in an alcoholic hydroxy group with an acid-decomposable group, and a group formed by replacing a hydrogen atom in a phenolic hydroxy group with an acid-decomposable group.
The repeating unit having an acid-decomposable group is preferably a repeating unit represented by general formula (AI) below.
In general formula (AI),
Xa1 represents a hydrogen atom, a halogen atom, a hydroxy group, or an organic group.
T represents a single bond or a divalent linking group.
Rx1 to Rx3 each independently represent a hydrocarbon group.
Two selected from the group consisting of Rx1 to Rx3 may be bonded together to form a ring.
The organic group represented by Xa1 is preferably an alkyl group. The alkyl group may be linear or branched. The alkyl group may have a substituent. The alkyl group is, for example, a methyl group or a group represented by —CH2—R11. Rn represents a halogen atom (such as a fluorine atom), a hydroxy group, or a monovalent organic group, and examples thereof include alkyl groups having 5 or less carbon atoms and optionally substituted with a halogen atom, acyl groups having 5 or less carbon atoms and optionally substituted with a halogen atom, and alkoxy groups having 5 or less carbon atoms and optionally substituted with a halogen atom. Ru is preferably an alkyl group having 3 or less carbon atoms and more preferably a methyl group. Xa1 is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
Examples of the divalent linking group represented by T include alkylene groups, aromatic ring groups, a —COO-Rt-group, and an —O-Rt-group. In these formulas, Rt represents an alkylene group or a cycloalkylene group.
T is preferably a single bond or a —COO-Rt-group and more preferably a single bond. When T represents a —COO-Rt-group, Rt is preferably an alkylene group having 1 to 5 carbon atoms and more preferably a —CH2— group, a —(CH2)2— group, or a —(CH2)3— group.
The number of carbon atoms in the hydrocarbon group represented by each of Rx1 to Rx3 is preferably 1 to 10. The hydrocarbon group may have a substituent.
Preferably, the hydrocarbon group represented by each of Rx1 to Rx3 is an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group.
The alkyl group represented by each of Rx1 to Rx3 may be linear or may be branched. The alkyl group may have a substituent. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, or a t-butyl group.
The cycloalkyl group represented by each of Rx1 to Rx3 may be a monocyclic cycloalkyl group or may be a polycyclic cycloalkyl group. The cycloalkyl group may have a substituent. The cycloalkyl group is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. In the cycloalkyl group, for example, one of the methylene groups forming the ring may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a group including a heteroatom such as a carbonyl group, or a vinylidene group. In the cycloalkyl group, at least one ethylene group included in the cycloalkane ring may be replaced with a vinylene group.
The aryl group represented by each of Rx1 to Rx3 may be a monocyclic aryl group or may be a polycyclic aryl group. The aryl group may have a substituent. The aryl group is preferably an aryl group having 6 to 10 carbon atoms and is, for example, a phenyl group, a naphthyl group, or an anthryl group.
The alkenyl group represented by each of Rx1 to Rx3 may be linear or may be branched. The alkenyl group may have a substituent. The alkenyl group is preferably a vinyl group.
When two selected from the group consisting of Rx1 to Rx3 are bonded together to form a ring, the ring formed may be a monocyclic ring or may be a polycyclic ring. The ring formed is preferably a cycloalkyl group. The cycloalkyl group is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. Moreover, the cycloalkyl group is preferably a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. In particular, the cycloalkyl group is preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms.
In the cycloalkyl group formed by bonding two selected from the group consisting of Rx1 to Rx3, for example, one of the methylene groups forming the ring may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a group including a heteroatom such as a carbonyl group, or a vinylidene group. In the cycloalkyl group, at least one ethylene group included in the cycloalkane ring may be replaced with a vinylene group.
When any of the above-described groups has a substituent, no particular limitation is imposed on the substituent. Examples of the substituent include alkyl groups (having 1 to 4 carbon atoms), halogen atoms, a hydroxy group, alkoxy groups (having 1 to 4 carbon atoms), alkylthio groups (having 1 to 4 carbon atoms), a carboxy group, and alkoxycarbonyl groups (having 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.
Preferably, the resin (A) include a repeating unit represented by the following general formula (1).
In general formula (1),
Xa1 represents a hydrogen atom, a halogen atom, a hydroxy group, or an organic group.
Rx1 to Rx3 each independently represent a hydrocarbon group.
Two selected from the group consisting of Rx1 to Rx3 may be bonded together to form a ring.
The repeating unit represented by general formula (1) is typically a repeating unit having an acid-decomposable group.
Xa1 in general formula (1) has the same meaning as that of Xa1 in general formula (AI) above, and its specific examples and preferred ranges are also the same as those of Xa1 in general formula (AI).
Rx1 to Rx3 in general formula (1) have the same meanings as those of Rx1 to Rx3 in general formula (AI) above, and their specific examples and preferred ranges are also the same as those of Rx1 to Rx3 in general formula (AI).
The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by the following general formula (AX2).
In general formula (AX2),
Xa1 represents a hydrogen atom, a halogen atom, a hydroxy group, or an organic group.
Rx1 to Rx3 each independently represent a hydrocarbon group.
Two selected from the group consisting of Rx1 to Rx3 may be bonded together to form a ring.
Ar1 represents a divalent aromatic hydrocarbon group.
Xa1 in general formula (AX2) has the same meaning as that of Xa1 in general formula (AI) above, and its specific examples and preferred ranges are also the same as those of Xa1 in general formula (AI).
Rx1 to Rx3 in general formula (AX2) have the same meanings as those of Rx1 to Rx3 in general formula (AI) above, and their specific examples and preferred ranges are also the same as those of Rx1 to Rx3 in general formula (AI).
Ar1 in general formula (AX2) is preferably an arylene group, more preferably an arylene group having 6 to 20 carbon atoms, still more preferably an arylene group having 6 to 10 carbon atoms, and particularly preferably a phenylene group. Ar1 may have a substituent, and examples of the substituent include alkyl groups (having 1 to 4 carbon atoms), halogen atoms, a hydroxy group, alkoxy groups (having 1 to 4 carbon atoms), a carboxy group, and alkoxycarbonyl groups (having 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.
When the resin (A) includes a group formed by replacing a hydrogen atom in a phenolic hydroxy group with an acid-decomposable group, it is preferably that the resin (A) has a repeating unit having a structure in which the hydrogen atom in the phenolic hydroxy group is protected by a group represented by any of formulas (Y1) to (Y4).
The repeating unit including the group formed by replacing the hydrogen atom in the phenolic hydroxy group with an acid-decomposable group is preferably a repeating unit represented by the following general formula (AII).
In general formula (AII),
R61, R62, and R63 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. R62 may be bonded to Ar6 to form a ring. In this case, R62 represents a single bond or an alkylene group.
X6 represents a single bond, —COO—, or —CONR64—. R64 represents a hydrogen atom or an alkyl group.
L6 represents a single bond or an alkylene group.
Ar6 represents an (n+1) valent aromatic hydrocarbon group. When Ar6 is bonded to R62 to form a ring, Ar6 represents an (n+2) valent aromatic hydrocarbon group.
When n≥2, Y2's each independently represent a hydrogen atom or a group that leaves by the action of an acid. However, at least one of Y2's represents a group that leaves by the action of an acid.
The group that is represented by Y2 and leaves by the action of an acid is preferably a group represented by any of formulas (Y1) to (Y4) above.
n represents an integer of 1 to 4.
Any of these groups may have a substituent. Examples of the substituent include alkyl groups (having 1 to 4 carbon atoms), halogen atoms, a hydroxy group, alkoxy groups (having 1 to 4 carbon atoms), a carboxy group, and alkoxycarbonyl groups (having 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.
The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by the following formula (AIII).
L1 represents a divalent linking group optionally having a fluorine atom or an iodine atom, and R1 represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group optionally having a fluorine atom or an iodine atom, or an aryl group optionally having a fluorine atom or an iodine atom. R2 represents a leaving group that optionally has a fluorine atom or an iodine atom and leaves by the action of an acid. At least one of L1, R1, or R2 has a fluorine atom or an iodine atom.
L1 represents a divalent linking group optionally having a fluorine atom or an iodine atom. Examples of the divalent linking group optionally having a fluorine atom or an iodine atom include —CO—, —O—, —S—, —SO—, —SO2—, hydrocarbon groups optionally having a fluorine atom or an iodine atom (such as alkylene groups, cycloalkylene groups, alkenylene groups, and arylene groups), and linking groups formed by linking a plurality of groups selected from the above groups. In particular, L1 is preferably —CO—, an arylene group, or -arylene group-fluorine or iodine atom-containing alkylene group- and more preferably —CO— or -arylene group-fluorine or iodine atom-containing alkylene group-.
The arylene group is preferably a phenylene group.
The alkylene group may by a linear or branched alkylene group. No particular limitation is imposed on the number of carbon atoms in the alkylene group, but the number of carbon atoms is preferably 1 to 10 and more preferably 1 to 3.
No particular limitation is imposed on the total number of fluorine or iodine atoms included in the fluorine or iodine atom-containing alkylene group, but the total number of fluorine or iodine atoms is preferably two or more, more preferably 2 to 10, and still more preferably 3 to 6.
R1 represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group optionally having a fluorine atom or an iodine atom, or an aryl group optionally having a fluorine atom or an iodine atom.
The alkyl group may be a linear or branched alkyl group. No particular limitation is imposed on the number of carbon atoms in the alkyl group, but the number of carbon atoms is preferably 1 to 10 and more preferably 1 to 3.
No particular limitation is imposed on the total number of fluorine or iodine atoms included in the fluorine or iodine atom-containing alkyl group, but the total number of fluorine or iodine atoms is preferably 1 or more, more preferably 1 to 5, and still more preferably 1 to 3.
The alkyl group may include a heteroatom such as an oxygen atom other than halogen atoms.
R2 represents a leaving group that leaves by the action of an acid and that optionally has a fluorine atom or an iodine atom. Examples of the leaving group optionally having a fluorine atom or an iodine atom include leaving groups represented by formulas (Y1) to (Y4) described above and having a fluorine atom or an iodine atom.
When the resin (A) includes the repeating unit having an acid-decomposable group, no particular limitation is imposed on the content of the repeating unit having an acid-decomposable group. The content of the repeating unit having an acid-decomposable group with respect to the total amount of repeating units in the resin (A) is preferably 15% by mole or more, more preferably 20% by mole or more, and still more preferably 30% by mole or more. The content of the repeating unit having an acid-decomposable group with respect to the total amount of the repeating units in the resin (A) is preferably 90% by mole or less, more preferably 80% by mole or less, still more preferably 70% by mole or less, and particularly preferably 60% by mole or less.
The resin (A) may include one type of repeating unit having an acid-decomposable group or may include two or more types.
Specific examples of the repeating unit having an acid-decomposable group are shown below, but the present invention is not limited thereto. In the following formulas, Xa1 represents any of H, CH3, CF3, and CH2OH, and Rxa and Rxb each represents a linear or branched alkyl group having 1 to 5 carbon atoms.
The resin (A) may have a repeating unit having an acid-decomposable group including an unsaturated bond.
The repeating unit having the acid-decomposable group including an unsaturated bond is preferably a repeating unit represented by formula (B).
In formula (B),
Xb represents a hydrogen atom, a halogen atom, or an alkyl group optionally having a substituent.
L represents a single bond or a divalent linking group optionally having a substituent.
Ry1 to Ry3 each independently represent a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an alkenyl group, an alkynyl group, or a monocyclic or polycyclic aryl group. However, at least one of Ry1, Ry2, or Ry3 represents an alkenyl group, an alkynyl group, a monocyclic or polycyclic cycloalkenyl group, or a monocyclic or polycyclic aryl group.
Two selected from the group consisting of Ry1 to Ry3 may be bonded together to form a monocyclic or polycyclic ring (such as a monocyclic or polycyclic cycloalkyl group or a monocyclic or polycyclic cycloalkenyl group).
The alkyl group optionally having a substituent and represented by Xb is, for example, a methyl group or a group represented by —CH2—R11. R11 represents a halogen atom (such as a fluorine atom), a hydroxy group, or a monovalent organic group, and examples thereof include alkyl groups having 5 or less carbon atoms and optionally substituted with a halogen atom, acyl groups having 5 or less carbon atoms and optionally substituted with a halogen atom, and alkoxy groups having 5 or less carbon atoms and optionally substituted with a halogen atom. Rn is preferably an alkyl group having 3 or less carbon atoms and more preferably a methyl group. Xb is preferably a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
Examples of the divalent linking group represented by L include an -Rt- group, a —CO— group, a —COO-Rt- group, a —COO-Rt-CO— group, an -Rt-CO— group, and an —O-Rt- group. In these formulas, Rt represents an alkylene group, a cycloalkylene group, or an aromatic ring group and is preferably an aromatic ring group.
L is preferably an -Rt- group, a —CO— group, a —COO-Rt-CO— group, or an -Rt-CO— group. Rt may have a substituent such as a halogen atom, a hydroxy group, or an alkoxy group. Rt is preferably an aromotic group optionally having a substituent such as a halogen atom, a hydroxy group, or an alkoxy group.
The alkyl group represented by each of Ry1 to Ry3 is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, or a t-butyl group.
The cycloalkyl group represented by each of Ry1 to Ry3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group.
The aryl group represented by each of Ry1 to Ry3 is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
The alkenyl group represented by each of Ry1 to Ry3 is preferably a vinyl group.
The alkynyl group represented by each of Ry1 to Ry3 is preferably an ethynyl group.
The cycloalkenyl group represented by each of Ry1 to Ry3 is preferably a structure including a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group with a double bond present in part of the monocyclic cycloalkyl group.
The cycloalkyl group formed by bonding two selected from the group consisting of Ry1 to Ry3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. The cycloalkyl group is also preferably a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. In particular, the cycloalkyl group is more preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms.
In the cycloalkyl or cycloalkenyl group formed by bonding two selected from the group consisting of Ry1 to Ry3, for example, one methylene group included in the ring may be replaced with a heteroatom such as an oxygen atom, a group including a heteroatom such as a carbonyl group, an —SO2— group, or an —SO3— group, a vinylidene group, or a combination thereof. In the cycloalkyl or cycloalkenyl group, at least one ethylene group included in the cycloalkane or cycloalkenyl ring may be replaced with a vinylene group.
In the repeating unit represented by formula (B), it is preferable that, for example, Ry1 is a methyl group, an ethyl group, a vinyl group, an allyl group, or an aryl group and that Ry2 and Ry3 are bonded together to form the cycloalkyl or cycloalkenyl group described above.
When any of the groups described above has a substituent, examples of the substituent include alkyl groups (having 1 to 4 carbon atoms), halogen atoms, a hydroxy group, alkoxy groups (having 1 to 4 carbon atoms), a carboxy group, and alkoxycarbonyl groups (having 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.
The repeating unit represented by formula (B) is preferably an acid-decomposable (meth)acrylic acid tertiary ester-based repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a —CO— group), an acid-decomposable hydroxystyrene tertiary alkyl ether-based repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a phenyl group), or an acid-decomposable styrenecarboxylic acid tertiary ester-based repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents an -Rt-CO— group (Rt is an aromatic group)).
When the resin (A) includes the repeating unit having the acid-decomposable group including an unsaturated bond, the content of the repeating unit having the acid-decomposable group including an unsaturated bond with respect to the total amount of the repeating units in the resin (A) is preferably 15% by mole or more, more preferably 20% by mole or more, and still more preferably 30% by mole or more. The content of the repeating unit having the acid-decomposable group including an unsaturated bond with respect to the total amount of the repeating units in the resin (A) is preferably 80% by mole or less, more preferably 70% by mole or less, and particularly preferably 60% by mole or less.
Specific example of the repeating unit having the acid-decomposable group including an unsaturated bond are shown below, but the invention is not limited thereto. In the formulas below, Xb and L1 each represent any of the above-described substituents and linking groups, and Ar represents an aromatic group. R represents a substituent such as a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxy group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (—OCOR′″ or —COOR′″: R′″ represents an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxy group, and R′ represents a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an alkenyl group, an alkynyl group, or a monocyclic or polycyclic aryl group. Q represents a heteroatom such as an oxygen atom, a group including a heteroatom such as a carbonyl group, an —SO2— group, or an —SO3— group, a vinylidene group, or a combination thereof. 1, n and m each represent an integer of 0 or more.
The resin (A) may have a repeating unit having a polar group.
Examples of the polar group include a hydroxy group, a cyano group, and a carboxy group.
The repeating unit having the polar group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with the polar group. It is also preferable that the repeating unit having the polar group does not have an acid-decomposable group. In the alicyclic hydrocarbon structure substituted with the polar group, the alicyclic hydrocarbon structure is preferably an adamantyl group or a norbornyl group.
The repeating unit having the polar group may have a pentafluorosulfanyl group or may not have a pentafluorosulfanyl group.
Specific examples of the monomer corresponding to the repeating unit having the polar group are shown below, but the invention is not limited to these specific examples. The specific examples shown below are methacrylate compounds but these may be acrylate compounds.
Other specific examples of the repeating unit having the polar group include structural units disclosed in paragraphs 0415 to 0433 of US2016/0070167A.
The resin (A) may include only one type of repeating unit having the polar group or may include two or more types.
When the resin (A) includes the repeating unit having the polar group, its content with respect to the total amount of the repeating units in the resin (A) is preferably 0.1% by mole to 40% by mole and more preferably 1 to 30% by mole.
The resin (A) may include a repeating unit other than the repeating units described above.
The resin (A) may include, for example, at least one repeating unit selected from the following group A and/or at least one repeating unit selected from the following group B.
Group A: The group consisting of the following repeating units (20) to (29).
(20) A repeating unit having an acid group, which will be described later.
(21) A repeating unit having a fluorine atom or an iodine atom, which will be described later.
(22) A repeating unit having a lactone group, a sultone group, or a carbonate group, which will be described later.
(23) A repeating unit having a photoacid generating group, which will be described later.
(24) A repeating unit represented by formula (V-1) or formula (V-2) below, which will be described later.
(25) A repeating unit represented by formula (A), which will be described later.
(26) A repeating unit represented by formula (B), which will be described later.
(27) A repeating unit represented by formula (C), which will be described later.
(28) A repeating unit represented by formula (D), which will be described later.
(29) A repeating unit represented by formula (E), which will be described later.
Group B: The group consisting of the following repeating units (30) to (32).
(30) A repeating unit having at least one group selected from the group consisting of lactone groups, sultone groups, carbonate groups, a hydroxy group, a cyano group, and alkali-soluble groups, which will be described later.
(31) A repeating unit having an alicyclic hydrocarbon structure and exhibiting no acid decomposability, which will be described later.
(32) A repeating unit represented by formula (III) and having no hydroxy group and no cyano group, which will be described later.
The resin (A) has preferably an acid group and includes preferably a repeating unit having an acid group as described later. The definition of the acid group will be described later along with preferred modes of the repeating unit having an acid group. When the resin (A) has the acid group, the interaction between the resin (A) and the acid generated from a compound (B) is enhanced. This results in a further reduction in diffusion of the acid, and a pattern to be formed may have a sharper rectangular cross-sectional shape.
When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV light, it is preferable that the resin (A) has at least one repeating unit selected from the group A.
When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV light, it is preferable that the resin (A) includes at least one of a fluorine atom or an iodine atom. When the resin (A) includes both a fluorine atom and an iodine atom, the resin (A) may have one type of repeating unit including both a fluorine atom and an iodine atom or may include two types of repeating units including a repeating unit including a fluorine atom and a repeating unit including an iodine atom.
When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV light, it is also preferable that the resin (A) has a repeating unit having an aromatic group.
When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF light, it is preferable that the resin (A) has at least one type of repeating unit selected from the group B.
When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF light, it is preferable that the resin (A) includes no fluorine atom and no silicon atom.
When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF light, it is preferable that the resin (A) has no aromatic group.
Preferably, the resin (A) has at least one selected from the group consisting of lactone groups, carbonate groups, sultone groups, and cyclic groups having a hydroxy group. The lactone groups, the carbonate groups, and the sultone groups will be described later. The cyclic group having a hydroxy group is preferably an alicyclic group having a hydroxy group, and specific examples thereof include those exemplified later for the repeating unit having an acid group.
Preferably, the resin (A) includes a repeating unit having an acid group.
The acid group is preferably an acid group having a pKa of 13 or less. As described above, the acid dissociation constant of the acid group is preferably 13 or less, more preferably 3 to 13, and still more preferably 5 to 10.
When the resin (A) has the acid group having a pKa of 13 or less, no particular limitation is imposed on the content of the acid group in the resin (A), but the content is often 0.2 to 6.0 mmol/g. In particular, the content is preferably 0.8 to 6.0 mmol/g, more preferably 1.2 to 5.0 mmol/g, and still more preferably 1.6 to 4.0 mmol/g. When the content of the acid group is within the above range, development proceeds smoothly, and a pattern to be formed has a good profile, so that high resolution is achieved.
The acid group is preferably, for example, a carboxy group, a phenolic hydroxy group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic group, a sulfonamido group, or an isopropanol group.
In the hexafluoroisopropanol group, one or more (preferably one to two) fluorine atoms may each be replaced with a group other than a fluorine atom (such as an alkoxycarbonyl group). The acid group is also preferably —C(CF3)(OH)—CF2— formed as described above. At least one fluorine atom may be replaced with a group other than a fluorine atom to form a ring including —C(CF3)(OH)—CF2—.
Preferably, the repeating unit having the acid group is a repeating unit different from the above-described repeating unit having a structure in which a polar group is protected by a leaving group that leaves by the action of an acid and from a repeating unit having a lactone group, a sultone group, or a carbonate group that is described later.
The repeating unit having the acid group may have a pentafluorosulfanyl group or may not have a pentafluorosulfanyl group.
The repeating unit having the acid group may have a fluorine atom or an iodine atom.
Examples of the repeating unit having the acid group include the following repeating units.
Preferably, the resin (A) includes a repeating unit having a phenolic hydroxy group.
The repeating unit having a phenolic hydroxy group is preferably a repeating unit represented by the following general formula (Y).
In general formula (Y),
A represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, or a cyano group.
L represents a single bond or a divalent linking group having an oxygen atom.
R represents a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an aralkyl group, an alkoxy group, an alkylcarbonyloxy group, an alkylsulfonyloxy group, an alkyloxycarbonyl group, or an aryloxycarbonyl group. When a plurality of R's are present, they may be the same or different. When a plurality of R's are present, they may together form a ring. R is preferably a hydrogen atom.
a represents an integer of from 1 to 3.
b represents and integer of 0 to (5−a).
R in general formula (Y) is preferably a hydrogen atom. L is preferably a single bond.
Examples of the repeating unit having the acid group are shown below. In the following formulas, a represents an integer of 1 to 3. R represents a hydrogen atom or a methyl group.
When the resin (A) includes the repeating unit having the acid group, the content of the repeating unit having the acid group with respect to the total amount of the repeating units in the resin (A) is preferably 10% by mole or more and more preferably 15% by mole or more. The content of the repeating unit having the acid group with respect to the total amount of the repeating units in the resin (A) is preferably 70% by mole or less, more preferably 65% by mole or less, and still more preferably 60% by mole or less.
The resin (A) may include only one type of repeating unit having the acid group or may include two or more types.
The resin (A) may have, in addition to the above-described <repeating unit having the acid-decomposable group> and the above-described <repeating unit having the acid group>, a repeating unit having a fluorine atom, a bromine atom, or an iodine atom. Preferably, the <repeating unit having a fluorine atom, a bromine atom, or an iodine atom> differs from other types of repeating units belonging to the group A such as the <repeating unit having a lactone group, a sultone group, or a carbonate group> described later and the <repeating unit having a photoacid generating group> described later.
The repeating unit having a fluorine atom, a bromine atom, or an iodine atom may have a pentafluorosulfanyl group or may not have a pentafluorosulfanyl group.
The repeating unit having a fluorine atom, a bromine atom, or an iodine atom is preferably a repeating unit represented by formula (C).
L5 represents a single bond or an ester group.
R9 represents a hydrogen atom or an alkyl group optionally having a fluorine atom, a bromine atom, or an iodine atom.
R10 represents a hydrogen atom, an alkyl group optionally having a fluorine atom, a bromine atom, or an iodine atom, a cycloalkyl group optionally having a fluorine atom, a bromine atom, or an iodine atom, an aryl group optionally having a fluorine atom, a bromine atom, or an iodine atom, or a combination thereof.
Examples of the repeating unit having a fluorine atom or an iodine atom are shown below.
When the resin (A) includes the repeating unit having a fluorine atom, a bromine atom, or an iodine atom, the content of the repeating unit having a fluorine atom, a bromine atom, or an iodine atom with respect to the total amount of the repeating units in the resin (A) is preferably 0% by mole or more, more preferably 5% by mole or more, and still more preferably 10% by mole or more. The content of the repeating unit having a fluorine atom, a bromine atom, or an iodine atom with respect to the total amount of the repeating units in the resin (A) is preferably 50% by mole or less, more preferably 45% by mole or less, and still more preferably 40% by mole or less.
The resin (A) may include only one type of repeating unit having a fluorine atom, a bromine atom, or an iodine atom or may include two or more types.
As described above, the repeating unit having a fluorine atom, a bromine atom, or an iodine atom does not include the <repeating unit having the acid-decomposable group> and the <repeating unit having the acid group>. Therefore, the content of the repeating unit having a fluorine atom, a bromine atom, or an iodine atom means the content of the repeating unit having a fluorine atom, a bromine atom, or an iodine atom excluding the <repeating unit having the acid-decomposable group> and the <repeating unit having the acid group>.
Among the repeating units in the resin (A), the total amount of repeating units including at least one of a fluorine atom, a bromine atom, or an iodine atom with respect to the total amount of the repeating units in the resin (A) is preferably 10% by mole or more, more preferably 20% by mole or more, still more preferably 30% by mole or more, and particularly preferably 40% by mole or more. No particular limitation is imposed on the upper limit of the total amount, but the amount with respect to the total amount of the repeating units in the resin (A) is, for example, 100% by mole or less.
Examples of the repeating units including at least one of a fluorine atom, a bromine atom, or an iodine atom include: a repeating unit having a fluorine atom, a bromine atom, or an iodine atom and having the acid-decomposable group; a repeating unit having a fluorine atom, a bromine atom, or an iodine atom and having the acid group; and a repeating unit having a fluorine atom, a bromine atom, or an iodine atom.
<Repeating Unit Having at Least One Group Selected from Group Consisting of Lactone Groups, Sultone Groups, Carbonate Groups, Hydroxy Group, Cyano Group, and Alkali-Soluble Groups>
The resin (A) may have a repeating unit having at least one group selected from the group consisting of lactone groups, sultone groups, carbonate groups, a hydroxy group, a cyano group, and alkali-soluble groups.
Preferably, the resin (A) includes a repeating unit having at least one selected from the group consisting of lactone groups and cyclic carbonate groups.
First, the repeating unit having at least one selected from the group consisting of lactone groups, sultone groups, and carbonate groups (which may be correctively referred to also as a “repeating unit having a lactone group, a sultone group, or a carbonate group”) will be described.
Preferably, the repeating unit having a lactone group, a sultone group, or a carbonate group does not have a hydroxy group and acid groups such as a hexafluoropropanol group.
The repeating unit having at least one group selected from the group consisting of lactone groups, sultone groups, carbonate groups, a hydroxy group, a cyano group, and alkali-soluble groups may have a pentafluorosulfanyl group or may not have a pentafluorosulfanyl group.
The lactone or sultone group may be any lactone or sultone group so long as it has a lactone or sultone structure. The lactone or sultone structure is preferably a 5- to 7-membered lactone or sultone structure. In particular, a 5- to 7-membered lactone structure with another ring structure fused thereto to form a bicyclo or spiro structure or a 5- to 7-membered sultone structure with another ring structure fused thereto to form a bicyclo or spiro structure is more preferred.
Preferably, the resin (A) has a repeating unit having a lactone or sultone group formed by removing at least one hydrogen atom from a ring member atom of a lactone structure represented by any of the following formulas (LC1-1) to (LC1-21) or a sultone structure represented by any of the following formulas (SL1-1) to (SL1-3).
The lactone or sultone group may be bonded directly to the main chain. For example, a ring member atom of the lactone or sultone group may be included in the main chain of the resin (A).
Each of the lactone and sultone structural moieties may have a substituent (Rb2). Preferred examples of the substituent (Rb2) include alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 4 to 7 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkoxycarbonyl groups having 1 to 8 carbon atoms, a carboxy group, halogen atoms, a cyano group, and acid-decomposable groups. n2 represents an integer of from 0 to 4. A plurality of Rb2's present when n2 is 2 or more may be different from each other, and the plurality of Rb2's present may be bonded together to form a ring.
Examples of the repeating unit having a group including the lactone structure represented by any of formulas (LC1-1) to (LC1-21) or the sultone structure represented by any of formulas (SL1-1) to (SL1-3) include a repeating unit represented by the following formula (AI-2).
In formula (AI-2), Rb0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. The alkyl group represented by Rb0 may have a substituent, and preferred examples of the substituent include a hydroxy group and halogen atoms.
Examples of the halogen atom represented by Rb0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb0 is preferably a hydrogen atom or a methyl group.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxy group, or a divalent group formed by combining any of the above groups. In particular, Ab is preferably a single bond or a linking group represented by -Ab1-CO2—. Ab1 is a linear or branched alkylene group or a monocyclic or polycyclic cycloalkylene group and is preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group, or a norbornylene group.
V represents a group formed by removing one hydrogen atom from a ring member atom in the lactone structure represented by any of formulas (LC1-1) to (LC1-21) or a group formed by removing one hydrogen atom from a ring member atom in the sultone structure represented by any of formulas (SL1-1) to (SL1-3).
When the repeating unit having the lactone or sultone group has optical isomers, any of the optical isomers may be used. One optical isomer may be used alone, or a mixture of a plurality of optical isomers may be used. When one optical isomer is mainly used, the optical purity (ee) thereof is preferably 90% or more and more preferably 95% or more.
The carbonate group is preferably a cyclic carbonate group (cyclic carbonic acid ester group).
The repeating unit having a cyclic carbonic acid ester group is preferably a repeating unit represented by the following formula (A-1).
In formula (A-1), RA1 represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably a methyl group).
n represents an integer of 0 or more.
RA2 represents a substituent. A plurality of RA2's present when n is 2 or more may be the same or different.
A represents a single bond or a divalent linking group. The divalent linking group is preferably an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxy group, or a divalent group formed by combining any of them.
Z represents an atomic group forming a monocyclic or polycyclic ring together with a group represented by —O—CO—O— in formula (A-1).
Examples of the repeating unit having a lactone group, a sultone group, or a carbonate group are shown below. In these formulas, Rx represents a hydrogen atom, —CH3, —CH2OH, or —CF3.
Next, the repeating unit having a hydroxy group or a cyano group will be described.
The resin (A) may have the repeating unit having a hydroxy group or a cyano group. In this case, the adhesiveness to a substrate and the affinity for a developer are improved.
The repeating unit having a hydroxy group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxy group or a cyano group.
Preferably, the repeating unit having a hydroxy group or a cyano group has no acid-decomposable group. Examples of the repeating unit having a hydroxy group or a cyano group include those described in paragraphs to of JP2014-98921A.
Next, the repeating unit having an alkali-soluble group will be described.
The resin (A) may have the repeating unit having an alkali-soluble group.
Examples of the alkali-soluble group include a carboxy group, a sulfonamido group, a sulfonylimido group, a bissulfonylimido group, and aliphatic alcohol groups substituted with an electron-withdrawing group at the α-position (e.g., a hexafluoroisopropanol group), and the alkali-soluble group is preferably a carboxy group. When the resin (A) includes the repeating unit having the alkali-soluble group, resolution in contact hole applications is increased. Examples of the repeating unit having the alkali-soluble group include those described in paragraphs [0085] and [0086] of JP2014-98921A.
The content of the repeating unit having at least one group selected from the group consisting of lactone groups, sultone groups, carbonate groups, a hydroxy group, a cyano group, and alkali-soluble groups with respect to the total amount of the repeating units in the resin (A) is preferably 1% by mole or more and more preferably 10% by mole or more. The upper limit of the content with respect to the total amount of the repeating units in the resin (A) is preferably 85% by mole or less, more preferably 80% by mole or less, still more preferably 70% by mole or less, and particularly preferably 60% by mole or less.
The resin (A) may include only one type of repeating unit having at least one group selected from the group consisting of lactone groups, sultone groups, carbonate groups, a hydroxy group, a cyano group, and alkali-soluble groups or may include two or more types.
The resin (A) may include a repeating unit that is different from those described above and has a group that generates an acid when irradiated with actinic rays or radiation (this group is hereinafter referred to also as a “photoacid generating group”).
The repeating unit having the photoacid generating group may have a pentafluorosulfanyl group or may not have a pentafluorosulfanyl group.
Examples of the repeating unit having the photoacid generating group include a repeating unit represented by the following formula (4).
R41 represents a hydrogen atom or a methyl group. L41 represent a single bond or a divalent linking group. L42 represents a divalent linking group. R41 represents a structural moiety that is decomposed when irradiated with actinic rays or radiation and thereby generates an acid on a side chain.
Examples of the repeating unit having the photoacid generating group are shown below.
Other examples of the repeating unit represented by formula (4) include repeating units described in paragraphs [0094] to [0105] of JP2014-041327A and repeating units described in paragraph [0094] of WO2018/193954A.
When the resin (A) includes the repeating unit having the photoacid generating group, the content of the repeating unit having the photoacid generating group with respect to the total amount of the repeating units in the resin (A) is preferably 1% by mole or more and more preferably 5% by mole or more. The content of the repeating unit having the photoacid generating group with respect to the total amount of the repeating units in the resin (A) is preferably 40% by mole or less, more preferably 35% by mole or less, and still more preferably 30% by mole or less.
The resin (A) may include only one type of the repeating unit having the photoacid generating group or may include two or more types.
The resin (A) may have a repeating unit represented by formula (V-1) or (V-2) below. Preferably, the repeating unit represented by the following formula (V-1) or (V-2) differs from the repeating units described above.
The repeating unit represented by formula (V-1) or (V-2) below may have a pentafluorosulfanyl group or may not have a pentafluorosulfanyl group.
In these formulas,
R6 and R7 each independently represent a hydrogen atom, a hydroxy group, an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (—OCOR or —COOR: R represents an alkyl group having 1 to 6 carbon atoms or a fluorinated alkyl group having 1 to 6 carbon atoms), or a carboxy group. The alkyl group is preferably a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms.
n3 represents an integer of from 0 to 6.
n4 represents an integer of from 0 to 4.
X4 is a methylene group, an oxygen atom, or a sulfur atom.
Examples of the repeating unit represented by formula (V-1) or (V-2) are shown below.
Examples of the repeating unit represented by formula (V-1) or (V-2) include repeating units described in paragraph [0100] of WO2018/193954A.
The higher the glass transition temperature (Tg) of the resin (A), the better because excessive diffusion of the acid generated or pattern collapse during development can be prevented. The Tg is preferably higher than 90° C., more preferably higher than 100° C., still more preferably higher than 110° C., and particularly preferably higher than 125° C. If the Tg is excessively high, the dissolution rate in a developer decreases. Therefore, the Tg is preferably 400° C. or lower and more preferably 350° C. or lower.
In the present specification, the glass transition temperature (Tg) of a polymer such as the resin (A) (hereinafter referred to as the “Tg of a repeating unit”) is computed by the following method. First, the Tg of each of the homopolymers formed from the respective repeating units included in the polymer is computed by the Bicerano method. Next, the mass ratios (%) of the repeating units with respect to the total mass of the repeating units in the polymer are computed. Next, the Tg of each repeating unit at the corresponding mass ratio is computed using the Fox formula (described, for example, in Materials Letters 62 (2008) 3152), and the computed Tg's are summed to obtain the Tg (° C.) of the polymer.
The Bicerano method is described in Prediction of polymer properties, Marcel Dekker Inc, New York (1993). The computation of Tg by the Bicerano method can be performed using software for estimating physical properties of a polymer, MDL Polymer (MDL Information Systems, Inc.).
To increase the Tg of the resin (A) (to increase the Tg to preferably higher than 90° C.), it is preferable to reduce the mobility of the main chain of the resin (A). Examples of a method for reducing the mobility of the main chain of the resin (A) include methods (a) to (e) described below.
Preferably, the resin (A) has a repeating unit whose homopolymer has a Tg of 130° C. or higher.
No particular limitation is imposed on the type of repeating unit whose homopolymer has a Tg of 130° C. or higher, and any repeating unit can be used so long as the Tg of the homopolymer computed by the Bicerano method is 130° C. or higher. With repeating units represented by formulas (A) to (E) described below, homopolymers formed from the repeating units can have a Tg of 130° C. or higher, but this depends on the types of functional groups in the repeating units.
(Repeating unit represented by formula (A))
One specific example of means for achieving the method (a) is a method in which the repeating unit represented by formula (A) is introduced into the resin (A).
In formula (A), RA represents a group including a polycyclic structure. Rx represents a hydrogen atom, a methyl group, or an ethyl group. The group including the polycyclic structure is a group including a plurality of ring structures, and the plurality of ring structures may or may not be fused.
Specific examples of the repeating unit represented by formula (A) include those described in paragraphs [0107] to [0119] of WO2018/193954A.
(Repeating unit represented by formula (B))
One specific example of means for achieving the method (b) is a method in which the repeating unit represented by formula (B) is introduced into the resin (A).
In formula (B), Rb1 to Rb4 each independently represent a hydrogen atom or an organic group, and at least two selected from the group consisting of Rb1 to Rb4 each represent an organic group.
When at least one of the organic groups is a group whose ring structure is linked directly to the main chain of the repeating unit, no particular limitation is imposed on the types of other organic groups.
When each of the organic groups is not a group whose ring structure is linked directly to the main chain of the repeating unit, at least two of the organic groups are each a substituent in which the number of constituent atoms excluding hydrogen atoms is 3 or more.
Specific examples of the repeating unit represented by formula (B) include those described in paragraphs [0113] to [0115] of WO2018/193954A.
One specific example of means for achieving the method (c) is a method in which the repeating unit represented by formula (C) is introduced into the resin (A).
In formula (C), Rc1 to Rc4 each independently represent a hydrogen atom or an organic group, and at least one of Rc1, Rc2, Rc3, or Rc4 is a group including a hydrogen-bonding hydrogen atom at a position within 3 atoms from a carbon atom in the main chain. In particular, it is preferable that the hydrogen-bonding hydrogen atom is present at a position within two atoms (at a position closer to the main chain) in order to induce the interaction between the main chains of molecules of the resin (A).
Specific examples of the repeating unit represented by formula (C) include those described in paragraphs [0119] to [0121] of WO2018/193954A.
One specific example of means for achieving the method (d) is a method in which the repeating unit represented by formula (D) is introduced into the resin (A).
In formula D, “Cylic” represents a group having a ring structure forming the main chain. No particular limitation is imposed on the number of atoms forming the ring.
Specific examples of the repeating unit represented by formula (D) include those described in paragraphs [0126] to [0127] of WO2018/193954A.
One specific example of means for achieving the method (e) is a method in which the repeating unit represented by formula (E) is introduced into the resin (A).
In formula (E), Re's each independently represent a hydrogen atom or an organic group. Examples of the organic group include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, and alkenyl groups, each of which may have a substituent.
“Cylic” is a cyclic group including a carbon atom included in the main chain. No particular limitation is imposed on the number of atoms included in the cyclic group.
Specific examples of the repeating unit represented by formula (E) include those described in paragraphs [0131] to [0133] of WO2018/193954A.
The resin (A) may have a repeating unit having an alicyclic hydrocarbon structure and exhibiting no acid decomposability. In this case, elution of a low-molecular weight component from the resist film to an immersion liquid during liquid immersion exposure can be reduced. Examples of such a repeating unit include repeating units derived from 1-adamantyl (meth)acrylate, diamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate, and cyclohexyl (meth)acrylate.
The resin (A) may have a repeating unit represented by formula (III) and having no hydroxy group and no cyano group.
In formula (III), R5 represents a hydrocarbon group having at least one ring structure and having no hydroxy group and no cyano group.
Ra represents a hydrogen atom, an alkyl group, or a —CH2—O—Ra2 group. In this formula, Ra2 represents a hydrogen atom, an alkyl group, or an acyl group.
Examples of the repeating unit represented by formula (III) and having no hydroxy group and no cyano group include those described in paragraphs [0087] to [0094] of JP2014-98921A.
The resin (A) may further have a repeating unit other than the repeating units described above.
For example, the resin (A) may have a repeating unit selected from the group consisting of a repeating unit having an oxathiane ring group, a repeating unit having an oxazolone ring group, a repeating unit having a dioxane ring group, and a repeating unit having a hydantoin ring group.
Examples of such a repeating unit are shown below.
The resin (A) may have, in addition to the repeating units described above, various repeating units for the purpose of controlling dry etching resistance, suitability for a standard developer, adhesiveness to a substrate, a resist profile, resolution, heat resistance, sensitivity, etc.
Preferably, the resin (A) include a repeating unit having a pentafluorosulfanyl group.
No particular limitation is imposed on the content of the repeating unit having a pentafluorosulfanyl group. The content of the repeating unit having a pentafluorosulfanyl group with respect to the total amount of the repeating units in the resin (A) is preferably 1% by mole or more, more preferably 5% by mole or more, and still more preferably 10% by mole or more. The content of the repeating unit having a pentafluorosulfanyl group with respect to the total amount of the repeating units in the resin (A) is preferably 70% by mole or less, more preferably 65% by mole or less, still more preferably 60% by mole or less, and particularly preferably 55% by mole or less.
The resin (A) may include only one type of repeating unit having a pentafluorosulfanyl group or may contain two or more types.
Preferably, the resin (A) includes a repeating unit formed by polymerization of a polymerizable group in a polymerizable compound represented by any of general formulas (2), (3), and (4) below.
The repeating unit formed by polymerization of the polymerizable group in the polymerizable compound represented by any of general formulas (2), (3), and (4) below is a repeating unit having a pentafluorosulfanyl group.
The repeating unit formed by polymerization of the polymerizable group in the polymerizable compound represented by general formula (2) is referred to also as a “repeating unit (2).”
In general formula (2),
Z1 represents a group having the polymerizable group.
E1 represents a single bond or a linking group.
Xa represents a halogen atom, a hydroxy group, or an organic group. When a plurality of Xa's are present, the plurality of Xa's may be the same or different.
m1 is an integer of 1 or more and (5+2k) or less.
m2 is an integer of 0 or more and (5+2k−m1) or less.
k is an integer of 0 or more.
Each * represents a direct bond bonded to an aromatic hydrocarbon shown in general formula (2).
In general formula (2), Z1 represents a group having the polymerizable group.
No particular limitation is imposed on the polymerizable group in Z1. Preferably the polymerizable group is a group including an unsaturated double bond. Examples thereof include a (meth)acryloyl group, a vinyl group, an allyl group, and a styryl group, and a (meth)acryloyl group is preferred.
Z1 may be a group composed only of the polymerizable group or may be a group composed of the polymerizable group and another group. Examples of the group composed of the polymerizable group and another group include a group formed by replacing at least one hydrogen atom in the polymerizable group with a substituent (such as any of the substituents T described above).
In general formula (2), E1 represents a single bond or a linking group.
No particular limitation is imposed on the linking group represented by E1. Examples of the linking group include —O—, —CO—, —COO—, —S—, —SO—, —SO2—, -NE2-, hydrocarbon groups (such as alkylene groups, cycloalkylene groups, alkenylene groups, and arylene groups), heteroarylene groups, and groups formed by linking any of the above groups. E2 represents a hydrogen atom or an organic group.
When E2 represents an organic group, the organic group is preferably an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group.
The alkyl group represented by E2 is, for example, preferably an alkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, or a dodecyl group and more preferably an alkyl group having 8 or less carbon atoms.
The alkyl group represented by E2 may have a substituent.
The alkylene group represented by E1 may have a substituent and is preferably an alkylene group having 1 to 8 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, or an octylene group.
The cycloalkylene group represented by E1 may have a substituent and is preferably a cycloalkylene group having 5 to 12 carbon atoms such as a cyclopentylene group, a cyclohexylene group, or an adamantylene group. In the cycloalkylene group, for example, one of the methylene groups forming the ring may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a group including a heteroatom such as a carbonyl group, or a vinylidene group. In the cycloalkylene group, at least one ethylene group included in the cycloalkane ring may be replaced with a vinylene group.
The alkenylene group represented by E1 may have a substituent and is preferably an alkenylene group having 2 to 8 carbon atoms.
The arylene group represented by E1 may have a substituent and is preferably an arylene group having 6 to 14 carbon atoms. Specific examples of the arylene group include a phenylene group, a tolylene group, a naphthylene group, and a biphenylene group, and a phenylene group is particularly preferred.
The heteroarylene group represented by E1 is a divalent aromatic group having a heteroatom as a ring member (a divalent aromatic heterocyclic group), and examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. The number of carbon atoms in the heteroarylene group is preferably 4 to 20 and more preferably 5 to 12. Examples of the heteroarylene group include groups formed by removing two hydrogen atoms from pyrrole, furan, thiophene, indole, benzofuran, benzothiophene, etc.
The heteroarylene group represented by E1 may have a substituent.
Preferably, E1 represents a single bond, an arylene group, a cycloalkylene group, an alkylene group, an alkenylene group, —O—, —CO—, —COO—, -NE2-, or a divalent linking group formed by combining any of these groups.
In general formula (2), Xa represents a halogen atom, a hydroxy group, or an organic group.
The halogen atom represented by Xa is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom and more preferably a fluorine atom or an iodine atom.
Preferably, the organic group represented by Xa represents an alkyl group, a cycloalkyl group, or an aryl group.
The alkyl group represented by Xa is preferably an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, or a t-butyl group.
The cycloalkyl group represented by Xa is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. In the cycloalkyl group, for example, one of the methylene groups forming the ring may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a group including a heteroatom such as a carbonyl group, or a vinylidene group. In the cycloalkyl group, at least one ethylene group included in the cycloalkane ring may be replaced with a vinylene group.
The aryl group represented by Xa is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
In general formula (2), k represents an integer of 0 or more and is preferably 0 or 1 and more preferably 0.
In general formula (2), m1 represents an integer of 1 or more and (5+2k) or less and is preferably an integer of 1 to 7 and more preferably an integer of 1 to 5.
In general formula (2), m2 represents an integer of 0 or more and (5+2k−m1) or less and is preferably an integer of 0 to 6 and more preferably 0 to 4.
The repeating unit (2) is preferably a repeating unit formed by polymerization of a polymerizable group in a polymerizable compound represented by the following general formula (2A).
In general formula (2A),
Z1 represents a group having the polymerizable group.
E1 represents a single bond or a linking group.
Xa represents a halogen atom, a hydroxy group, or an organic group. When a plurality of Xa's are present, the plurality of Xa's may be the same or different.
m1 represents an integer of 1 or more and (5+2k) or less.
m2 represents an integer of 0 or more and (5+2k−m1) or less.
k represents an integer of 0 or more.
In general formula (2A), Z1, E1, Xa, m1, m2, and k have the same meanings as those of Z1, E1, Xa, m1, m2, and k in general formula (2), and their specific examples and preferred ranges are also the same as those of Z1, E1, Xa, m1, m2, and k in general formula (2).
The repeating unit (2) may have an acid-decomposable group. The acid-decomposable group is as described above.
When the resin (A) includes the repeating unit (2), no particular limitation is imposed on the content of the repeating unit (2). The content of the repeating unit (2) with respect to the total amount of the repeating units in the resin (A) is preferably 1% by mole or more, more preferably 5% by mole or more, and still more preferably 10% by mole or more. The content of the repeating unit (2) with respect to the total amount of the repeating units in the resin (A) is preferably 70% by mole or less, more preferably 65% by mole or less, still more preferably 60% by mole or less, and particularly preferably 55% by mole or less.
The resin (A) may include only one type of repeating unit (2) or may include two or more types.
Examples of the polymerizable compound represented by general formula (2) are shown below, but the polymerizable compound is not limited thereto.
The repeating unit formed by polymerization of the polymerizable group in the polymerizable compound represented by general formula (3) is referred to also as a “repeating unit (3).
In general formula (3),
Z1 represents a group having the polymerizable group.
E1 represents a single bond or a linking group.
W1 represents a group having a lactone structure.
m3 represents an integer of 1 or more.
In general formula (3), Z1 has the same meaning as that of Z1 in general formula (2) above, and its specific examples and preferred ranges are also the same as those of Z1 in general formula (2).
In general formula (3), E1 has the same meaning as that of E1 in general formula (2) above, and its specific examples and preferred ranges are also the same as those of E1 in general formula (2).
In general formula (3), W1 represents a group having a lactone structure.
The lactone structure represented by W1 is preferably a monocyclic or polycyclic lactone structure having 4 or more carbon atoms and more preferably a 5- to 7-membered lactone structure. A group in which another ring structure is fused to the 5- to 7-membered lactone structure so as to form a bicyclo structure or a spiro structure is also preferred.
Preferably, the lactone structure is a lactone structure represented by any of formulas (LC1-1) to (LC1-21) above.
In general formula (3), m3 represents an integer of 1 or more and is preferably an integer of 1 to 5.
The repeating unit (3) may have an acid-decomposable group. The acid-decomposable group is as described above.
When the resin (A) includes the repeating unit (3), no particular limitation is imposed on the content of the repeating unit (3). The content of the repeating unit (3) with respect to the total amount of the repeating units in the resin (A) is preferably 1% by mole or more, more preferably 5% by mole or more, and still more preferably 10% by mole or more. The content of the repeating unit (3) with respect to the total amount of the repeating units in the resin (A) is preferably 80% by mole or less, more preferably 75% by mole or less, still more preferably 70% by mole or less, and particularly preferably 65% by mole or less.
The resin (A) may include only one type of repeating unit (3) or may include two or more types.
An example of the polymerizable compound represented by general formula (3) is shown below, but the polymerizable compound is not limited thereto.
The repeating unit formed by polymerization of the polymerizable group in the polymerizable compound represented by general formula (4) is referred to also as a “repeating unit (4).”
In general formula (4),
Z1 represents a group having the polymerizable group.
E1 represents a single bond or a linking group.
Rx4 and Rx5 each independently represent a hydrogen atom or an organic group.
Rx4 and Rx5 may be bonded together to form a ring.
In general formula (4), Z1 has the same meaning as that of Z1 in general formula (2) above, and its specific examples and preferred ranges are also the same as those of Z1 in general formula (2).
In general formula (4), E1 has the same meaning as that of E1 in general formula (2) above, and its specific examples and preferred ranges are also the same as those of E1 in general formula (2).
In general formula (4), Rx4 and Rx5 each independently represent a hydrogen atom or an organic group. Rx4 and Rx5 may be bonded together to form a ring.
No particular limitation is imposed on the number of carbon atoms in the organic group represented by each of Rx4 and Rx5. The number of carbon atoms is preferably 1 to 20 and more preferably 1 to 10.
The organic group represented by each of Rx4 and Rx5 is preferably an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group.
The alkyl group represented by each of Rx4 and Rx5 may be linear or may be branched. The alkyl group may have a substituent. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, or a t-butyl group. These alkyl groups may each have a substituent.
The cycloalkyl group represented by each of Rx4 and Rx5 may be a monocyclic cycloalkyl group or may be a polycyclic cycloalkyl group. The cycloalkyl group may have a substituent. The cycloalkyl group is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. In the cycloalkyl group, for example, one of the methylene groups forming the ring may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a group including a heteroatom such as a carbonyl group, or a vinylidene group. In the cycloalkyl group, at least one ethylene group included in the cycloalkane ring may be replaced with a vinylene group. The cycloalkyl group may have a substituent.
The aryl group represented by each of Rx4 and Rx5 may be a monocyclic aryl group or may be a polycyclic aryl group. The aryl group may have a substituent. The aryl group is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
The alkenyl group represented by each of Rx4 and Rx5 may be linear or may be branched. The alkenyl group may have a substituent. The alkenyl group is preferably a vinyl group.
When Rx4 and Rx5 are bonded together to form a ring, the ring formed may be monocyclic group or may be a polycyclic group. The ring formed is preferably a cycloalkyl group. The cycloalkyl group is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. The cycloalkyl group is also preferably a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. In particular, the cycloalkyl group is preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms.
In the cycloalkyl group formed by bonding Rx4 and Rx5 together, for example, one of the methylene groups forming the ring may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a group including a heteroatom such as a carbonyl group, or a vinylidene group. In the cycloalkyl group, at least one ethylene group included in the cycloalkane ring may be replaced with a vinylene group.
When any of the above groups has a substituent, no particular limitation is imposed on the substituent. Examples of the substituent include alkyl groups (having, for example, 1 to 4 carbon atoms), halogen atoms, a hydroxy group, alkoxy groups (having, for example, 1 to 4 carbon atoms), alkylthio groups (having, for example, 1 to 4 carbon atoms), a carboxy group, and alkoxycarbonyl groups (having, for example, 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.
The repeating unit (4) may have an acid-decomposable group. The acid-decomposable group is as described above.
When the resin (A) includes the repeating unit (4), no particular limitation is imposed on the content of the repeating unit (4). The content of the repeating unit (4) with respect to the total amount of the repeating units in the resin (A) is preferably 1% by mole or more, more preferably 5% by mole or more, and still more preferably 10% by mole or more. The content of the repeating unit (4) with respect to the total amount of the repeating units in the resin (A) is preferably 80% by mole or less, more preferably 75% by mole or less, still more preferably 70% by mole or less, and particularly preferably 65% by mole or less.
The resin (A) may include only one type of repeating unit (4) or may include two or more types.
Examples of the polymerizable compound represented by general formula (4) are shown below, but the polymerizable compound is not limited thereto.
The resin (A) may further include a repeating unit having a pentafluorosulfanyl group other than the repeating unit formed by polymerization of the polymerizable group in the polymerizable compound represented by any of general formulas (2), (3), and (4) above.
Examples of the polymerizable compound that provides the repeating unit having a pentafluorosulfanyl group other than the repeating unit formed by polymerization of the polymerizable group in the polymerizable compound represented by any of general formulas (2), (3), and (4) above are shown below, but the polymerizable compound is not limited thereto.
Preferably, in the resin (A) (particularly when the resist composition is used as a resist composition for ArF light), all the repeating units are composed of repeating units derived from compounds having an ethylenically unsaturated bond. In particular, it is also preferable that all the repeating units are composed of (meth)acrylate-based repeating units. In the resin (A) used in this case, all the repeating units may be methacrylate-based repeating units, or all the repeating units may be acrylate-based repeating units. Alternatively, the repeating units may each be a methacrylate-based repeating unit or an acrylate-based repeating unit. It is preferable that the content of the acrylate-based repeating units with respect to the total amount of the repeating units is 50% by mole or less.
The resin (A) can be synthesized by a routine method (for example, radical polymerization).
No particular limitation is imposed on the weight average molecular weight of the resin (A) that is determined as a polystyrene-equivalent value by the GPC method. The weight average molecular weight is preferably 30000 or less, more preferably 1000 to 30000, still more preferably 3000 to 30000, and particularly preferably 4500 to 15000.
The dispersity (molecular weight distribution) of the resin (A) is generally 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and still more preferably 1.2 to 2.0. The smaller the dispersity, the better the resolution and the resist profile, and the smoother the side surfaces of the resist pattern, so that better roughness quality is obtained.
No particular limitation is imposed on the content of the resin (A) in the actinic ray-sensitive or radiation-sensitive resin composition of the invention, and the content can be adjusted according to the type of resin (A), the intended purpose of the resin (A), etc.
When the resin (A) is used as an acid-decomposable resin, the content of the resin (A) in the actinic ray-sensitive or radiation-sensitive resin composition of the invention with respect to the total amount of solids in the actinic ray-sensitive or radiation-sensitive resin composition is preferably 10.0% by mass or more, more preferably 20.0 to 99.9% by mass, still more preferably 40.0 to 90.0% by mass, and particularly preferably 60.0 to 80.0% by mass.
When the resin (A) is not used as an acid-decomposable resin but is used as an additive, the content of the resin (A) in the actinic ray-sensitive or radiation-sensitive resin composition of the invention with respect to the total amount of the solids in the actinic ray-sensitive or radiation-sensitive resin composition is preferably 0.01 to 19.9% by mass, more preferably 0.1 to 15.0% by mass, and still more preferably 1.0 to 10.0% by mass.
One resin (A) may be used, or a plurality of resins (A) may be used in combination.
The actinic ray-sensitive or radiation-sensitive resin composition of the invention includes a solvent (preferably an organic solvent).
Preferably, the solvent includes at least one of (M1) propylene glycol monoalkyl ether carboxylate or (M2) at least one selected from the group consisting of propylene glycol monoalkyl ethers, lactates, acetates, alkoxypropionates, chain ketones, cyclic ketones, lactones, and alkylene carbonates. The solvent may further include a component other than the components (M1) and (M2).
The details of the components (M1) and (M2) are described in paragraphs [0218] to [0226] of WO2020/004306A, the contents of which are incorporated herein.
When the solvent further includes a component other than the components (M1) and (M2), the content of the component other than the components (M1) and (M2) with respect to the total amount of the solvent is preferably 5 to 30% by mass.
The composition of the invention may include a poor solvent including an organic solvent (Y) that is used for an “actinic ray-sensitive or radiation-sensitive resin composition manufacturing method” described later.
The content of the solvent in the actinic ray-sensitive or radiation-sensitive resin composition of the invention is determined such that the concentration of solids is preferably 0.5 to 30% by mass and more preferably 1 to 20% by mass. In this case, the coatability of the actinic ray-sensitive or radiation-sensitive resin composition of the invention can be further improved.
The solids mean all components other than the solvent.
[Compound that Generates Acid Upon Irradiation with Actinic Rays or Radiation (Photoacid Generator)]
Preferably, the actinic ray-sensitive or radiation-sensitive resin composition of the invention includes a compound that generates an acid upon irradiation with actinic rays or radiation (a photoacid generator).
The compound that generates an acid upon irradiation with actinic rays or radiation is referred to also as a “compound (B).”
The compound (B) may be in the form of a low-molecular weight compound or may be in the form in which the compound (B) is incorporated into part of a polymer (e.g., the resin (A)). A combination of the form of a low-molecular-weight compound and the form in which the compound (B) is incorporated into part of a polymer may also be used.
When the compound (B) is in the form of a low-molecular weight compound, the molecular weight of the compound (B) is preferably 3000 or less, more preferably 2000 or less, and still more preferably 1000 or less. No particular limitation is imposed on the lower limit of the molecular weight, but the molecular weight is 100 or more.
When the compound (B) is in the form in which the compound (B) is incorporated into part of a polymer, the compound (B) may be incorporated into part of the resin (A) or into a resin different from the resin (A).
In the present invention, it is preferable that the compound (B) is in the form of a low-molecular weight compound.
The compound (B) is, for example, a compound (onium salt) represented by “M+X−” and is preferably a compound that generates an organic acid upon exposure to light.
Examples of the organic acid include sulfonic acids (such as aliphatic sulfonic acids, aromatic sulfonic acids, and camphorsulfonic acid), carboxylic acids (such as aliphatic carboxylic acids, aromatic carboxylic acids, and aralkyl carboxylic acids), carbonylsulfonylimidic acid, bis(alkylsulfonyl)imidic acids, and tris(alkylsulfonyl)methide acids.
The molecular weight of the acid generated from the compound (B) is preferably 240 or more, more preferably 250 or more, still more preferably 260 or more, particularly preferably 270 or more, and most preferably 280 or more.
In the compound represented by “M+X−,” M+ represents an organic cation.
No particular limitation is imposed on the structure of the organic cation, and the valence of the organic cation may be 1 or two or more.
The organic cation is preferably a cation represented by general formula (ZaI) below (hereinafter referred to also as a “cation (ZaI)” or a cation represented by general formula (ZaII) below (hereinafter referred to also as a “cation (ZaII)”).
In general formula (ZaI), R201, R202, and R203 each independently represent an organic group.
In general formula (ZaII), R204 and R205 each independently represent an organic group.
General formulas (ZaI) and (ZaII) will be described later in detail. It is preferable that at least one of R201, R202, or R203 in general formula (ZaI) is an aryl group or at least one of R204 or R205 in general formula (ZaII) is an aryl group. The aryl group may have a substituent. The substituent is preferably halogen atom (preferably a fluorine atom or an iodine atom) or an organic group.
It is also preferable that at least one of R201, R202, or R203 in general formula (ZaI) has an acid-decomposable group or at least one of R204 or R205 in general formula (ZaII) has an acid-decomposable group. The acid-decomposable group is the same as the acid-decomposable group in the resin (A).
The mode in which at least one of R201, R202, or R203 in general formula (ZaI) has an acid-decomposable group is preferably a mode in which at least one of R201, R202, or R203 is an aryl group substituted with an organic group including the acid-decomposable group. The mode in which at least one of R204 or R205 in general formula (ZaII) has an acid-decomposable group is preferably a mode in which at least one of R204 or R205 is an aryl group substituted with an organic group including the acid-decomposable group.
The cation (ZaI) will be described.
The number of carbon atoms in each of the organic groups represented by R201, R202, and R203 is generally 1 to 30 and preferably 1 to 20. Two selected from the group consisting of R201 to R203 may be bonded together to form a ring structure, and the ring may include an oxygen atom, a sulfur atom, an ester group, an amido group, or a carbonyl group. Examples of the group formed from two selected from the group consisting of R201 to R203 that are bonded together include alkylene groups (such as a butylene group and a pentylene group) and —CH2—CH2—O—CH2—CH2—.
Preferred examples of the form of the organic cation in formula (ZaI) include a cation (ZaI-1), a cation (ZaI-2), an organic cation (cation (ZaI-3b)) represented by formula (ZaI-3b), and an organic cation (cation (ZaI-4b)) represented by formula (ZaI-4b) that will be described later.
First, the cation (ZaI-1) will be described.
The cation (ZaI-1) is an arylsulfonium cation in which at least one of R201, R202, or R203 in formula (ZaI) is an aryl group.
In the arylsulfonium cation, each of R201 to R203 may be an aryl group. Alternatively, some of R201 to R203 may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.
Alternatively, one of R201, R202, or R203 may be an aryl group, and the remaining two of R201 to R203 may be bonded together to form a ring structure. The ring may include an oxygen atom, a sulfur atom, an ester group, an amido group, or a carbonyl group. Examples of the group formed by bonding two selected from the group consisting of R201 to R203 together include alkylene groups in which at least one methylene group is replaced by an oxygen atom, a sulfur atom, an ester group, an amido group, and/or a carbonyl group (such as a butylene group, a pentylene group, and a —CH2—CH2—O—CH2—CH2—).
Examples of the arylsulfonium cation include a triarylsulfonium cation, diarylalkylsulfonium cations, aryldialkylsulfonium cations, diarylcycloalkylsulfonium cations, and aryldicycloalkylsulfonium cations.
Each aryl group included in the arylsulfonium cation is preferably a phenyl group or a naphthyl group and is more preferably a phenyl group. The aryl group may have a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, etc. Examples of the heterocyclic structure include a pyrrole residue, a furan residue, a thiophene residue, an indole residue, a benzofuran residue, and a benzothiophene residue. When the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group or the cycloalkyl group optionally included in the arylsulfonium cation is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms and more preferably a methyl group, an ethyl group, a propyl group, a n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, or a cyclohexyl group.
The aryl, alkyl, and cycloalkyl groups in R201 to R203 may each independently have a substituent, and the substituent is preferably an alkyl group (having, for example, 1 to 15 carbon atoms), a cycloalkyl group (having, for example, 3 to 15 carbon atoms), an aryl group (having, for example, 6 to 14 carbon atoms), an alkoxy group (having, for example, 1 to 15 carbon atoms), a cycloalkylalkoxy group (having, for example, 1 to 15 carbon atoms), a halogen atom (for example, fluorine or iodine), a hydroxy group, a carboxy group, an ester group, a sulfinyl group, a sulfonyl group, an alkylthio group, or a phenylthio group.
Each substituent may have a substituent if possible. It is also preferable that the alkyl group has a halogen atom as a substituent and is therefore a halogenated alkyl group such as a trifluoromethyl group.
It is also preferable that any of these substituents are combined together to form an acid-decomposable group.
The acid-decomposable group means a group that is decomposed by the action of an acid to generate a polar group and preferably has a structure in which the polar group is protected by a leaving group that leaves by the action of an acid. The polar group and the leaving group are as described above.
Next, the cation (ZaI-2) will be described.
The cation (ZaI-2) is a cation in which R201 to R203 in formula (ZaI) each independently represent an organic group having no aromatic ring. The aromatic ring is intended to encompass an aromatic ring including a heteroatom.
The number of carbon atoms in each of the organic groups having no aromatic ring and represented by R201 to R203 is generally 1 to 30 and preferably 1 to 20.
R201 to R203 each independently represent preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and still more preferably a linear or branched 2-oxoalkyl group.
Examples of the alkyl and cycloalkyl groups in R201 to R203 include: linear alkyl groups having 1 to 10 carbon atoms and branched alkyl groups having 3 to 10 carbon atoms (such as a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group); and cycloalkyl groups having 3 to 10 carbon atoms (such as a cyclopentyl group, a cyclohexyl group, and a norbornyl group).
R201 to R203 may each be further substituted with a halogen atom, an alkoxy group (having, for example, 1 to 5 carbon atoms), a hydroxy group, a cyano group, or a nitro group.
It is also preferable that the substituents in R201 to R203 are each independently combined with another substituent to form an acid-decomposable group.
Next, the cation (ZaI-3b) will be described.
The cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).
In formula (ZaI-3b),
R1c to R5c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxy group, a nitro group, an alkylthio group, or an arylthio group.
R6c and R7c each independently represent a hydrogen atom, an alkyl group (such as a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group.
Rx and Ry each independently represent an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.
R1c to R7c, Rx, and Ry may each have a substituent, and it is also preferable that these substituents are each independently combined with another substituent to form an acid-decomposable group.
A combination of two or more selected from the group consisting of R1c to R5c, a pair of R5c and R6c, a pair of R6c and R7c, a pair of R5c and Rx, and a pair of Rx and Ry may each be bonded together to form a ring. These rings may each independently include an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
Each ring may be an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic heterocyclic ring, or a polycyclic condensed ring formed by combining two or more of the above rings. The ring may be a 3- to 10-membered ring and is preferably a 4- to 8-membered ring and more preferably a 5- or 6-membered ring.
Examples of the groups formed by bonding two or more selected from the group consisting of R1c to R5c, bonding R6c and R7c, and bonding Rx and Ry include alkylene groups such as a butylene group and a pentylene group. A methylene group in the alkylene group may be replaced with a heteroatom such as an oxygen atom.
The group formed by bonding R5c and R6c and the group formed by bonding R5c and Rx are each preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group.
R1c to R5c, R6c, R7c, Rx, Ry, the ring formed by bonding together a combination of two or more selected from the group consisting of R1c to R5c, the ring formed by bonding together a pair of R5c and R6c, the ring formed by bonding together a pair of R6c and R7c, the ring formed by bonding together a pair of R5c and Rx, and the ring formed by bonding together a pair of Rx and Ry may each have a substituent.
Next, the cation (ZaI-4b) will be described.
The cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).
In formula (ZaI-4b),
l represents an integer of from 0 to 2.
r represents an integer of from 0 to 8.
R13 represents a hydrogen atom, a halogen atom (such as a fluorine atom or an iodine atom), a hydroxy group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxy group, an alkoxycarbonyl group, or a group including a cycloalkyl group (a cycloalkyl group itself or a group including a cycloalkyl group as a part thereof). These groups may each have a substituent.
R14 represents a hydroxy group, a halogen atom (such as a fluorine atom or an iodine atom), an alkyl group, a halogenated alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group including a cycloalkyl group (a cycloalkyl group itself or a group including a cycloalkyl group as a part thereof). These groups may each have a substituent. When a plurality of R14's are present, they each independently represent any of the above groups such as a hydroxy group.
R15's each independently represent an alkyl group, a cycloalkyl group, or a naphthyl group. The two R15's may be bonded together to form a ring. When the two R15's are bonded together to form a ring, the skeleton of the ring may include a heteroatom such as an oxygen atom or a nitrogen atom. In one preferred mode, the two R15's are each an alkylene group and are bonded together to form a ring structure. The above alkyl, cycloalkyl, and naphthyl groups and the ring formed by bonding the two R15's may each have a substituent.
In formula (ZaI-4b), the alkyl group represented by each of R13, R14, and R15s may be a linear or branched alkyl group. Preferably, the number of carbon atoms in the alkyl group is 1 to 10. Each alkyl group is more preferably a methyl group, an ethyl group, a n-butyl group, a t-butyl group, etc.
It is also preferable that the substituents in R13 to R15's, Rx, and Ry are each independently combined with another substituent to form an acid-decomposable group.
Next, formula (ZaII) will be described.
In formula (ZaII), R204 and R205 each independently represent an organic group and represent preferably an aryl group, an alkyl group, or a cycloalkyl group.
The aryl group represented by each of R204 and R205 is preferably a phenyl group or a naphthyl group and more preferably a phenyl group. The aryl group represented by each of R204 and R205 may be an aryl group having a heterocycle having an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.
The alkyl or cycloalkyl group represented by each of R204 and R205 is preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (such as a methyl group, an ethyl group, a propyl group, a butyl group, or a pentyl group) or is preferably a cycloalkyl group having 3 to 10 carbon atoms (such as a cyclopentyl group, a cyclohexyl group, or a norbornyl group).
The aryl, alkyl, and cycloalkyl groups represented by R204 and R205 may each independently have a substituent. Examples of the optional substituents in the aryl, alkyl, and cycloalkyl groups represented by R204 and R205 include alkyl groups (having, for example, 1 to 15 carbon atoms), cycloalkyl groups (having, for example, 3 to 15 carbon atoms), aryl groups (having, for example, 6 to 15 carbon atoms), alkoxy groups (having, for example, 1 to 15 carbon atoms), halogen atoms, a hydroxy group, and a phenylthio group. It is also preferable that the substituents in R204 and R205 are each independently combined with another substituent to form an acid-decomposable group.
Specific examples of the organic cation represented by M+ are shown below. However, the invention is not limited thereto.
In the compound represented by “M+X−,” X− represents an organic anion.
No particular limitation is imposed on the organic anion, and examples thereof include monovalent organic anions and divalent and higher valent organic anions.
The organic anion is preferably an anion whose ability to cause a nucleophilic reaction is very low and is more preferably a non-nucleophilic anion.
Examples of the non-nucleophilic anion include sulfonate anions (such as aliphatic sulfonate anions, aromatic sulfonate anions, and a camphorsulfonate anion), carboxylate anions (such as aliphatic carboxylate anions, aromatic carboxylate anions, and aralkyl carboxylate anions), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.
In the aliphatic sulfonate anions and the aliphatic carboxylate anions, the aliphatic moiety may be a linear or branched alkyl group or a cycloalkyl group and is preferably a linear or branched alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms.
The alkyl group may be, for example, a fluoroalkyl group (which may have a substituent other than a fluorine atom or may be a perfluoroalkyl group).
In the aromatic sulfonate anions and the aromatic carboxylate anions, the aryl group is preferably an aryl group having 6 to 14 carbon atoms such as a phenyl group, a tolyl group, or a naphthyl group.
The above-described alkyl, cycloalkyl, and aryl groups may each have a substituent. No particular limitation is imposed on the substituent, and specific examples thereof include a nitro group, halogen atoms such as a fluorine atom and a chlorine atom, a carboxy group, a hydroxy group, an amino group, a cyano group, alkoxy groups (having preferably 1 to 15 carbon atoms), alkyl groups (having preferably 1 to 10 carbon atoms), cycloalkyl groups (having preferably 3 to 15 carbon atoms), aryl groups (having preferably 6 to 14 carbon atoms), alkoxycarbonyl groups (having preferably 2 to 7 carbon atoms), acyl groups (having preferably 2 to 12 carbon atoms), alkoxycarbonyloxy groups (having preferably 2 to 7 carbon atoms), alkylthio groups (having preferably 1 to 15 carbon atoms), alkylsulfonyl groups (having preferably 1 to 15 carbon atoms), alkyliminosulfonyl groups (having preferably 1 to 15 carbon atoms), and aryloxysulfonyl groups (having preferably 6 to 20 carbon atoms).
In the aralkyl carboxylate anions, the aralkyl group is preferably an aralkyl group having 7 to 14 carbon atoms.
Examples of the aralkyl group having 7 to 14 carbon atoms include a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylbutyl group.
Examples of the sulfonylimide anion include a saccharin anion.
In the bis(alkylsulfonyl)imide anions and the tris(alkylsulfonyl)methide anions, the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. These alkyl groups may have a substituent, and examples of the substituent include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, and cycloalkylaryloxysulfonyl groups. The substituent is preferably a fluorine atom or an alkyl group substituted with a fluorine atom.
In the bis(alkylsulfonyl)imide anions, the alkyl groups may be bonded together to form a ring structure. In this case, the strength of the acid increases.
Other examples of the non-nucleophilic anion include phosphorus fluoride (such as PF6), boron fluoride (such as BF4−), and antimony fluoride (such as SbF6−).
The non-nucleophilic anion is preferably an aliphatic sulfonate anion substituted with a fluorine atom at least at the α-position of the sulfonic acid, an aromatic sulfonate anion substituted with a fluorine atom or a fluorine atom-containing group, a bis(alkylsulfonyl)imide anion in which an alkyl group is substituted with a fluorine atom, or a tris(alkylsulfonyl)methide anion in which an alkyl group is substituted with a fluorine atom. In particular, the non-nucleophilic anion is more preferably a perfluoroaliphatic sulfonate anion (having preferably 4 to 8 carbon atoms) or a benzenesulfonate anion having a fluorine atom and still more preferably a nonafluorobutanesulfonate anion, a perfluorooctanesulfonate anion, a pentafluorobenzenesulfonate anion, or a 3,5-bis(trifluoromethyl)benzenesulfonate anion.
Preferred examples of the non-nucleophilic anion include an anion represented by the following formula (AN4).
In formula (AN4), R1 to R3 each independently represent an organic group or a hydrogen atom. L represents a divalent linking group.
In formula (AN4), L represents a divalent linking group.
When a plurality of L's are present, L's may be the same or different.
Examples of the divalent linking group include —O—CO—O—, —COO—, —CONH—, —CO—, —O—, —S—, —SO—, —SO2—, alkylene groups (having preferably 1 to 6 carbon atoms), cycloalkylene groups (having preferably 3 to 15 carbon atoms), alkenylene groups (having preferably 2 to 6 carbon atoms), and divalent linking groups formed by combining any of the above groups. In particular, the divalent linking group is preferably —O—CO—O—, —COO—, —CONH—, —CO—, —O—, —SO2—, —O—CO—O-alkylene group-, —COO-alkylene group-, or —CONH-alkylene group- and more preferably —O—CO—O—, —O—CO—O-alkylene group-, —COO—, —CONH—, —SO2—, or —COO-alkylene group-.
For example, L is preferably a group represented by the following formula (AN4-2).
*a—(CR2a2)X-Q-(CR2b2)Y—*b (AN4-2)
In formula (AN4-2), *a represents a bonding position to R3 in formula (AN4).
*b represents a bonding position to —C(R1)(R2)— in formula (AN4).
X and Y each independently represent an integer of from 0 to 10 and preferably an integer of 0 to 3.
R2a and R2b each independently represent a hydrogen atom or a substituent.
When a plurality of R2a's are present, they may be the same or different. When a plurality of R2b's are present, they may be the same or different.
When Y is 1 or more, R2b in CR2b2 that is bonded directly to —C(R1)(R2)— in formula (AN4) differs from a fluorine atom.
Q represents *A—O—CO—O—*B, *A—CO—*B, *A—CO—O—*B, *A—O—CO—*B, *A—O—*B, *A—S—*B, or *A—SO2—*B
When X+Y in formula (AN4-2) is 1 or more and R2a's and R2b's in formula (AN4-2) are each a hydrogen atom, Q represents *A—O—COO—*B, *A—CO—*B, *A—O—CO—*B, *A—O—*B, *A—S—*B, or *A—SO2—*B
*A represents a bonding position on the R3 side in formula (AN4), and *B represents a bonding position on the —SO3— side in formula (AN4).
In formula (AN4), R1 to R3 each independently represent an organic group.
No particular limitation is imposed on the organic group, so long as it has at least one carbon atom. The organic group may be a linear group (e.g., a linear alkyl group), a branched group (e.g., a branched alkyl group such as a t-butyl group), or a cyclic group. The organic group may or may not have a substituent. The organic group may or may not have a heteroatom (such as an oxygen atom, a sulfur atom, and/or a nitrogen atom).
Other examples of the organic group include substituent groups other than electron-withdrawing groups.
Examples of the substituent group other than electron-withdrawing groups include hydrocarbon groups, a hydroxy group, oxyhydrocarbon groups, oxycarbonyl hydrocarbon groups, an amino group, hydrocarbon-substituted amino groups, and hydrocarbon-substituted amido groups.
Preferably, these substituent groups other than electron-withdrawing groups are each independently —R′, —OH, —OR′, —OCOR′, —NH2, —NR′2, —NHR′, or —NHCOR′. R′ is a monovalent hydrocarbon group.
Examples of the monovalent hydrocarbon group represented by R′ include: linear or branched monovalent hydrocarbon groups including alkyl groups such as a methyl group, an ethyl group, a propyl group, and a butyl group, alkenyl groups such as an ethenyl group, a propenyl group, and a butenyl group, and alkynyl groups such as an ethynyl group, a propynyl group, and a butynyl group; monovalent alicyclic hydrocarbon groups including cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and a adamantyl group and cycloalkenyl groups such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, and a norbornenyl group; and monovalent aromatic hydrocarbon groups including aryl groups such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group, a methylnaphthyl group, an anthryl group, and a methylanthryl group and aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and an anthrylmethyl group.
In particular, it is preferable that R1 and R2 each independently represent a hydrocarbon group (preferably a cycloalkyl group) or a hydrogen atom.
In particular, R3 is preferably an organic group having a ring structure. The ring structure may be a monocyclic structure or a polycyclic structure and may have a substituent. Preferably, the ring in the organic group including the ring structure is bonded directly to L in formula (AN4).
The organic group having the ring structure may or may not have, for example, a heteroatom (for example, an oxygen atom, a sulfur atom, and/or, a nitrogen atom). At least one carbon atom included in the ring structure may be replaced with a heteroatom.
The organic group having the ring structure is preferably a hydrocarbon group having a ring structure, a lactone ring group, or a sultone ring group. In particular, the organic group having the ring structure is preferably a hydrocarbon group having a ring structure.
The hydrocarbon group having a ring structure is preferably a monocyclic or polycyclic cycloalkyl group. These groups may have a substituent.
The cycloalkyl group may be a monocyclic group (such as a cyclohexyl group) or a polycyclic group (such as an adamantyl group), and the number of carbon atoms is preferably 5 to 12.
Preferably, the lactone group and the sultone group are each, for example, a group formed by removing one hydrogen atom from a ring member atom included in the lactone or sultone structure in any of the structures represented by formulas (LC1-1) to (LC1-21) and formulas (SL1-1) to (SL1-3) described above.
The non-nucleophilic anion is also preferably an anion represented by the following formula (AN1).
In formula (AN1), o represents an integer of from 1 to 3. p represents an integer of from 0 to 10. q represents an integer of from 0 to 10.
Xf represents a fluorine atom or an organic group. The organic group may be an organic group substituted with at least one fluorine atom or an organic group having no fluorine atom. The number of carbon atoms in the organic group (preferably an alkyl group) is preferably 1 to 10 and more preferably 1 to 4. The organic group (preferably an alkyl group) substituted with at least one fluorine atom is preferably a perfluoroalkyl group.
At least one Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms and more preferably a fluorine atom or CF3. It is still more preferable that each of Xf's is a fluorine atom.
R4 and R5 each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom. When a plurality of R4's are present, they may be the same or different. When a plurality of R5's are present, they may be the same or different.
The number of carbon atoms in each of the alkyl groups represented by R4 and R5 is preferably 1 to 4. Each alkyl group may have a substituent. R4 and R5 are each preferably a hydrogen atom.
Specific examples and preferred modes of the alkyl group substituted with at least one fluorine atom are the same as the specific examples and preferred modes of Xf in formula (AN1).
L represents a divalent linking group.
When a plurality of L's are present, they may be the same or different.
Examples of the divalent linking group include —O—CO—O—, —COO—, —CONH—, —CO—, —O—, —S—, —SO—, —SO2—, alkylene groups (having preferably 1 to 6 carbon atoms), cycloalkylene groups (having preferably 3 to 15 carbon atoms), alkenylene groups (having preferably 2 to 6 carbon atoms), and divalent linking groups formed by combining any of these groups. In particular, the divalent linking group is preferably —O—CO—O—, —COO—, —CONH—, —CO—, —O—, —SO2—, —O—CO—O-alkylene group-, —COO-alkylene group-, or —CONH-alkylene group- and more preferably —O—CO—O—, —O—CO—O-alkylene group-, —COO—, —CONH—, —SO2—, or —COO-alkylene group-.
W represents an organic group including a ring structure. In particular, W is preferably a cyclic organic group.
Examples of the cyclic organic group include alicyclic groups, aryl groups, and heterocyclic groups.
The alicyclic group may be a monocyclic alicyclic group or a polycyclic alicyclic group. Examples of the monocyclic alicyclic group include monocyclic cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic group include polycyclic cycloalkyl groups such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Of these, alicyclic groups having 7 or more carbon atoms and a bulky structure such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group are preferred.
The aryl group may be a monocyclic or polycyclic aryl group. Examples of such an aryl group include a phenyl group, a naphthyl group, a phenanthryl group, and an anthryl group.
The heterocyclic group may be a monocyclic or polycyclic heterocyclic group. In particular, when the heterocyclic group is a polycyclic heterocyclic group, diffusion of acid can be further reduced. The heterocyclic group may or may not have aromaticity. Examples of the heterocycle having aromaticity include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and a pyridine ring. Examples of the heterocycle having no aromaticity include a tetrahydropyran ring, lactone rings, sultone rings, and a decahydroisoquinoline ring. The heterocycle in the heterocyclic group is preferably a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring.
The above cyclic organic group may have a substituent. Examples of the substituent include alkyl groups (which may be linear or branched and have preferably 1 to 12 carbon atoms), cycloalkyl groups (which may be monocyclic, polycyclic, or spirocyclic and have preferably 3 to 20 carbon atoms), aryl groups (having preferably 6 to 14 carbon atoms), a hydroxy group, alkoxy groups, ester groups, amido groups, urethane groups, ureide groups, thioether groups, sulfonamido groups, and sulfonate groups. Carbon included in the cyclic organic group (carbon contributing to the formation of the ring) may be carbonyl carbon. Two or more substituents may be bonded together to form a ring. For example, two alkoxy groups or a hydroxy group and an alkoxy group may be bonded together to form a ring having a cyclic acetal structure. This ring may have a substituent. Examples of the substituent include alkyl groups (having 1 to 4 carbon atoms), halogen atoms, a hydroxy group, alkoxy groups (having 1 to 4 carbon atoms), a carboxyl group, and alkoxycarbonyl groups (having 2 to 6 carbon atoms).
The anion represented by formula (AN1) is preferably SO—CF2—CH2—OCO-(L)q-W, SO3−—CF2—CHF—CH2—OCO-(L)q-W, SO3−—CF2—COO-(L)q-W, SO3−—CF2—CF2—CH2—CH2-(L)q-W, or SO3−—CF2—CH(CF3)—OCO-(L)q′-W. L, q, and W are the same as those in formula (AN1). q′ represents an integer of from 0 to 10.
The anion represented by formula (AN1) is preferably any of the following modes (AN2) and (AN3).
Mode (AN2): In formula (AN1), o represents 2, and p represents 0. Two Xf s bonded to a carbon atom bonded directly to —SO3— (this carbon atom is hereinafter referred to also as a “carbon atom Z1”) each independently represent a hydrogen atom or an organic group having no fluorine atom. Two Xfs bonded to a carbon atom adjacent to the above carbon atom (this carbon atom is hereinafter referred to also as a “carbon atom Z2”) each independently represent a hydrogen atom or an organic group. Preferred modes of q, L, and W are the same as those described above.
The two Xfs bonded to the carbon atom Z1 are each preferably a hydrogen atom.
It is preferable that at least one of the two Xf s bonded to the carbon atom Z2 is a fluorine atom or an organic group having a fluorine atom. It is more preferable that both of the two Xf s bonded to the carbon atom Z2 are each a fluorine atom or an organic group having a fluorine atom. It is still more preferable that both are each an alkyl group substituted with fluorine.
Mode (AN3): In formula (AN1), one of the two Xfs represents a fluorine atom or an alkyl group substituted with at least one fluorine atom, and the other one represents a hydrogen atom or an organic group having no fluorine atom. Preferred modes of o, p, q, R4, R5, L, and W are the same as those described above.
The non-nucleophilic anion may be a benzenesulfonate anion and is preferably a benzenesulfonate anion substituted with a branched alkyl group or a cycloalkyl group.
The non-nucleophilic anion is also preferably an aromatic sulfonate anion represented by the following formula (AN5).
In formula (AN5), Ar represents an aryl group (such as a phenyl group) and may further have a substituent other than a sulfonate anion and the -(D-B) group. Examples of the substituent include a fluorine atom and a hydroxy group.
n represents an integer of 0 or more. n is preferably 1 to 4, more preferably 2 to 3, and still more preferably 3.
D represents a single bond or a divalent linking group. Examples of the divalent linking group include ether groups, thioether groups, a carbonyl group, sulfoxide groups, a sulfone group, sulfonate groups, ester groups, and groups formed by combining two or more of these groups.
B represents a hydrocarbon group.
Preferably, B has an aliphatic hydrocarbon structure. B is more preferably an isopropyl group, a cyclohexyl group, or an aryl group (such as a tricyclohexylphenyl group) optionally having a substituent.
B may further have a substituent represented by “-(L)q-W.” L, q, and W have the same meanings as those of L, q, and W in formula (AN1) above, and their specific examples and preferred ranges are also the same as those of L, q, and W in formula (AN1).
The non-nucleophilic anion is also preferably a disulfonamide anion.
The disulfonamide anion is, for example, an anion represented by N—(SO2—Rq)2.
Here, Rq represents an alkyl group optionally having a substituent and is preferably a fluoroalkyl group and more preferably a perfluoroalkyl group. Two Rq's may be bonded together to form a ring. The group formed by bonding two Rq's is preferably an alkylene group optionally having a substituent, more preferably a fluoroalkylene group, and still more preferably a perfluoroalkylene group. The number of carbon atoms in the alkylene group is preferably 2 to 4.
Other examples of the non-nucleophilic anion include anions represented by the following formulas (d1-1) to (d1-4).
In formula (d1-1), R1 represents a hydrocarbon group (e.g., an aryl group such as a phenyl group) optionally having a substituent (e.g., a hydroxy group).
In formula (d1-2), Z2c represents a hydrocarbon group having 1 to 30 carbon atoms and optionally having a substituent (provided that the carbon atom adjacent to S is not substituted with a fluorine atom).
The hydrocarbon group represented by Z2c may be linear or branched and may have a ring structure. A carbon atom in the hydrocarbon group (preferably, a carbon atom serving as a ring member atom when the hydrocarbon group has a ring structure) may be carbonyl carbon (—CO—). Examples of the hydrocarbon group include a group having a norbornyl group optionally having a substituent. A carbon atom included in the norbornyl group may be carbonyl carbon.
It is preferable that “Z2c—SO3—” in formula (d1-2) differs from the anions represented by formulas (AN4), (AN1), and (AN5) above. For example, Z2c differs from an aryl group. For example, in Z2c, the atoms at the α- and β-positions with respect to —SO3− are each preferably an atom different from a carbon atom having a fluorine atom as a substituent. For example, in Z2c, the atom at the α-position and/or the atom at the β-position with respect to —SO3− is preferably a ring member atom of the cyclic group.
In formula (d1-3), R52 represents an organic group (preferably a hydrocarbon group having a fluorine atom), and Y3 represents a linear, branched, or cyclic alkylene group, an arylene group, or a carbonyl group. Rf represents a hydrocarbon group.
In formula (d1-4), R53 to R14 each represent an organic group (preferably a hydrocarbon group having a fluorine atom). R53 to R14 may be bonded together to form a ring.
One type of organic anion may be used alone, or two or more types of organic anions may be used.
Preferably, the resist composition includes two or more compounds (B), or the compound (B) is at least one selected from the group consisting of compounds (I) and (II) below.
It is also preferable that the compound (B) is at least one selected from the group consisting of the compound (I) below and the compound (II) below.
The compound (I) is a compound having at least one structural moiety X described below and at least one structural moiety Y described below and is a compound that generates an acid including a first acidic moiety described below and derived from the structural moiety X and a second acidic moiety described below and derived from the structural moiety Y when irradiated with actinic rays or radiation.
Structural moiety X: A structural moiety including an anionic moiety A1− and a cationic moiety M1+ and forms the first acidic moiety represented by HA1 when irradiated with actinic rays or radiation.
Structural moiety Y: A structural moiety including an anionic moiety A2 and a cationic moiety M2+ and forms the second acidic moiety represented by HA2 when irradiated with actinic rays or radiation.
Preferably, the cationic moiety M1+ and the cationic moiety M2+ each independently represent an organic cation, and their specific examples and preferred modes are the same as those of the organic cation represented by M+ described above.
The compound (I) satisfies the following condition I.
Condition I: A compound PI formed by replacing each of the cationic moiety M1+ in the structural moiety X in the compound (I) and the cationic moiety M2+ in the structural moiety Y with H+ has an acid dissociation constant a1 derived from the acidic moiety represented by HA1 formed by replacing the cationic moiety M1+ in the structural moiety X with H+ and an acid dissociation constant a2 derived from the acidic moiety represented by HA2 formed by replacing the cationic moiety M2+ in the structural moiety Y with H+, and the acid dissociation constant a2 is larger than the acid dissociation constant a1.
The condition I will be specifically described.
When the compound (I) is a compound that generates an acid having one first acidic moiety derived from the structural moiety X and one second acidic moiety derived from the structural moiety Y, the compound PI corresponds to a “compound having HA1 and HA2.”
The acid dissociation constant a1 and the acid dissociation constant a2 of this compound PI will be specifically described. When the acid dissociation constants of the compound PI are determined, the pKa when the compound PI becomes a “compound having A1− and HA2” is the acid dissociation constant a1, and the pKa when the “compound having A1− and HA2” becomes a “compound having A1− and A2−” is the acid dissociation constant a2.
When the compound (I) is, for example, a compound that generates an acid having two first acidic moieties derived from the structural moieties X and one second acidic moiety derived from the structural moiety Y, the compound PI corresponds to a “compound having two HA1's and one HA2.”
When the acid dissociation constants of the compound PI are determined, the acid dissociation constant when the compound PI becomes a “compound having one A1−, one HA1, and one HA2,” and the acid dissociation constant when the “compound having one A1−, one HA1, and one HA2” becomes a “compound having two A1−'s and one HA2” each correspond to the acid dissociation constant a1. Moreover, the acid dissociation constant when the “compound having two A1−'s and one HA2” becomes a “compound having two A1−'s and A2−” corresponds to the acid dissociation constant a2. Specifically, such a compound PI has a plurality of acid dissociation constants derived from acidic moieties represented by HA1 formed by replacing cationic moieties M1+ in the structural moieties X with H+. In this case, the acid dissociation constant a2 is larger than the largest one of the plurality of acid dissociation constants a1. Let aa be the acid dissociation constant when the compound PI becomes the “compound having one A1−, one HA1, and one HA2,” and ab be the acid dissociation constant when the “compound having one A1−, one HA1, and one HA2” becomes the “compound having two A1− 's and one HA2.” Then aa and ab satisfy the relation aa<ab.
The acid dissociation constants a1 and a2 are determined by the acid dissociation constant measurement method described above.
The compound PI corresponds to the acid generated when the compound (I) is irradiated with actinic rays or radiation.
When the compound (I) has two or more structural moieties X, these structural moieties X may be the same or different. Moreover, two or more A1− 's may be the same or different, and two or more M1+ 's may be the same or different.
In compound (I), A1− and A2− may be the same or different, and M1+ and M2+ may be the same or different. However, it is preferable that A1− and A2− are different from each other.
In the compound PI, the difference (absolute difference) between the acid dissociation constant a1 (when a plurality of acid dissociation constants a1 are present, the maximum value of the acid dissociation constants) and the acid dissociation constant a2 is preferably 0.1 or more, more preferably 0.5 or more, and still more preferably 1.0 or more. No particular limitation is imposed on the upper limit of the difference (absolute difference) between the acid dissociation constant a1 (when a plurality of acid dissociation constants a1 are present, the maximum value of the acid dissociation constants) and the acid dissociation constant a2, but the upper limit is, for example, 16 or less.
In the compound PI, the acid dissociation constant a2 is, for example, 20 or less and preferably 15 or less. The lower limit of the acid dissociation constant a2 is preferably −4.0 or more.
In the compound PI, the acid dissociation constant a1 is preferably 2.0 or less and more preferably 0 or less. The lower limit of the acid dissociation constant a1 is preferably −20.0 or more.
The anionic moiety A1− and the anionic moiety A2 are each a structural moiety including a negatively charged atom or atomic group and are each, for example, a structural moiety selected from the group consisting of formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6) shown below.
The anionic moiety A1− is preferably a moiety capable of forming an acidic moiety having a small acid dissociation constant, more preferably a moiety represented by any one of (AA-1) to (AA-3), and still more preferably a moiety represented by any one of formulas (AA-1) and (AA-3).
The anionic moiety A2 is preferably a moiety capable of forming an acidic moiety having a larger acid dissociation constant than the anionic moiety A1−, more preferably a moiety represented by any one of formulas (BB-1) to (BB-6), and still more preferably a moiety represented by any one of formulas (BB-1) and (BB-4).
In formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6) below, * represents a bonding position.
No particular limitation is imposed on the specific structure of the compound (I), and examples thereof include compounds represented by formulas (Ia-1) to (Ia-5) described below.
First, the compound represented by formula (Ia-1) will be described.
The compound represented by formula (Ia-1) generates an acid represented by HA11-L1-A12H when irradiated with actinic rays or radiation.
In formula (Ia-1), M11+ and M12+ each independently represent an organic cation. A11− and A12− each independently represent a monovalent anionic functional group.
L1 represents a divalent linking group.
M11+ and M12+ may be the same or different.
A11− and A12− may be the same or different, but it is preferable that they differ from each other.
In a compound PIa (HA11-L1-A12H) formed by replacing each of the cations represented by M11+ and M12+ in formula (Ia-1) above with H+, the acid dissociation constant a2 derived from the acidic moiety represented by A12H is larger than the acid dissociation constant a1 derived from the acidic moiety represented by HA11. Preferred values of the acid dissociation constants a1 and a2 are as described above. The compound PIa is the same as the acid generated from the compound represented by formula (Ia-1) upon irradiation with actinic rays or radiation.
At least one of M11+, M12+, A11−, A12−, or L1 may have an acid-decomposable group as a substituent.
In formula (Ia-1), the organic cations represented by M11+ and M12+ are as described above.
The monovalent anionic functional group represented by A11− means a monovalent group including the anionic moiety A11− described above. The monovalent anionic functional group represented by A12− means a monovalent group including the anionic moiety A2 described above.
The monovalent anionic functional groups represented by A11− and A12− are each preferably a monovalent anionic functional group including the anionic moiety represented by any of formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6) described above and more preferably a monovalent anionic functional group selected from the group consisting of formulas (AX-1) to (AX-3) and formulas (BX-1) to (BX-7). In particular, the monovalent anionic functional group represented by A11− is preferably a monovalent anionic functional group represented by any of formulas (AX-1) to (AX-3). In particular, the monovalent anionic functional group represented by A12− is preferably a monovalent anionic functional group represented by any of formulas (BX-1) to (BX-7) and more preferably a monovalent anionic functional group represented by any of formulas (BX-1) to (BX-6).
In formulas (AX-1) to (AX-3), RA1 and RA2 each independently represent a monovalent organic group. * represents a bonding position.
Examples of the monovalent organic group represented by RA1 include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.
The monovalent organic group represented by RA2 is preferably a linear, branched, or cyclic alkyl group or an aryl group.
The number of carbon atoms in the alkyl group is preferably 1 to 15, more preferably 1 to 10, and still more preferably 1 to 6.
The alkyl group may have a substituent. The substituent is preferably a fluorine atom or a cyano group and more preferably a fluorine atom. When the alkyl group has a fluorine atom as a substituent, the alkyl group may be a perfluoroalkyl group.
The aryl group is preferably a phenyl group or a naphthyl group and more preferably a phenyl group.
The aryl group may have a substituent. The substituent is preferably a fluorine atom, an iodine atom, a perfluoroalkyl group (for example, having preferably 1 to 10 carbon atoms and more preferably 1 to 6 carbon atoms), or a cyano group and is more preferably a fluorine atom, an iodine atom, or a perfluoroalkyl group.
In formulas (BX-1) to (BX-4) and (BX-6), RB represents a monovalent organic group. * represents a bonding position.
The monovalent organic group represented by RB is preferably a linear, branched, or cyclic alkyl group or an aryl group.
The number of carbon atoms in the alkyl group is preferably 1 to 15, more preferably 1 to 10, and still more preferably 1 to 6.
The alkyl group may have a substituent. No particular limitation is imposed on the substituent, but the substituent is preferably a fluorine atom or a cyano group and more preferably a fluorine atom. When the alkyl group has a fluorine atom as a substituent, the alkyl group may be a perfluoroalkyl group.
When a carbon atom in the alkyl group at a bonding position (for example, the carbon atom in the alkyl group that is bonded directly to —CO— in any of formulas (BX-1) and (BX-4), the carbon atom shown in the alkyl group that is bonded directly to —SO2— in any of formulas (BX-2) and (BX-3), or the carbon atom shown in the alkyl group that is bonded directly to N− in formula (BX-6)) has a substituent, it is also preferable that the substituent differs from a fluorine atom and a cyano group.
In the alkyl group, a carbon atom may be replaced with carbonyl carbon.
The aryl group is preferably a phenyl group or a naphthyl group and more preferably a phenyl group.
The aryl group may have a substituent. The substituent is preferably a fluorine atom, an iodine atom, a perfluoroalkyl group (for example, having preferably 1 to 10 carbon atoms and more preferably 1 to 6 carbon atoms), a cyano group, an alkyl group (for example, having preferably 1 to 10 carbon atoms and more preferably 1 to 6 carbon atoms), an alkoxy group (for example, having preferably 1 to 10 carbon atoms and more preferably 1 to 6 carbon atoms), or an alkoxycarbonyl group (for example, having preferably 2 to 10 carbon atoms and more preferably 2 to 6 carbon atoms) and more preferably a fluorine atom, an iodine atom, a perfluoroalkyl group, an alkyl group, an alkoxy group, or an alkoxycarbonyl group.
In formula (Ia-1), no particular limitation is imposed on the divalent linking group represented by L1, and examples of L1 include —CO—, —NR—, —O—, —S—, —SO—, —SO2—, alkylene groups (which may be linear or branched and have preferably 1 to 6 carbon atoms), cycloalkylene groups (having preferably 3 to 15 carbon atoms), alkenylene groups (having preferably 2 to 6 carbon atoms), divalent aliphatic heterocyclic groups (preferably 5- to 10-membered rings, more preferably 5- to 7-membered rings, and still more preferably 5- to 6-membered rings, each of which has at least one N atom, 0 atom, S atom, or Se atom in the ring structure), divalent aromatic heterocyclic groups (preferably 5- to 10-membered rings, more preferably 5- to 7-membered rings, and still more preferably 5- to 6-membered rings, each of which has at least one N atom, 0 atom, S atom, or Se atom in the ring structure), divalent aromatic hydrocarbon ring groups (preferably 6- to 10-membered rings and more preferably 6-membered rings), and divalent linking groups formed by combining a plurality of groups selected from the above groups. R is a hydrogen atom or a monovalent organic group. No particular limitation is imposed on the monovalent organic group, but the monovalent organic group is preferably, for example, an alkyl group (having preferably 1 to 6 carbon atoms). The alkylene, cycloalkylene, alkenylene, divalent aliphatic heterocyclic, divalent aromatic heterocyclic, and divalent aromatic hydrocarbon ring groups described above may each have a substituent. Examples of the substituent include halogen atoms (preferably a fluorine atom).
In particular, the divalent linking group represented by L1 is preferably a divalent linking group represented by formula (L1).
In formula (L1), L111 represents a single bond or a divalent linking group.
No particular limitation is imposed on the divalent linking group represented by L111, and examples of the divalent linking group include —CO—, —NH—, —O—, —SO—, —SO2—, alkylene groups (which may be linear or branched and have preferably 1 to 6 carbon atoms) optionally having a substituent, cycloalkylene groups (having preferably 3 to 15 carbon atoms) optionally having a substituent, aryl groups (having preferably 6 to 10 carbon atoms) optionally having a substituent, and divalent linking groups formed by combining a plurality of groups selected from the above groups. No particular limitation is imposed on the substituent, and examples thereof include halogen atoms.
p represents an integer of from 0 to 3 and preferably represents an integer of from 1 to 3.
v represents an integer of 0 or 1.
Xf1 represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. In a case where p represents 2 or 3, Xfi's may be the same or different each other. The number of carbon atoms in the alkyl group is preferably 1 to 10 and more preferably 1 to 4. The alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group.
Xf2 represents a hydrogen atom, an alkyl group optionally having a fluorine atom as a substituent, or a fluorine atom. In a case where p represents 2 or 3, Xf21's may be the same or different each other. The number of carbon atoms in the alkyl group is preferably 1 to 10 and more preferably 1 to 4. In particular, each Xf2 represents preferably a fluorine atom or an alkyl group substituted with at least one fluorine atom and more preferably a fluorine atom or a perfluoroalkyl group.
In particular, Xf1's and Xf2's each independently represent preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms and more preferably a fluorine atom or CF3. In particular, it is still more preferable that Xf1's and Xf2's are each a fluorine atom.
* represents a bonding position.
When L1 in formula (Ia-1) represents a divalent linking group represented by formula (L1), it is preferable that the direct bond (*) on the L111 side in formula (L1) is bonded to A12− in formula (Ia-1).
Next, compounds represented by formulas (Ia-2) to (Ia-4) will be described.
In formula (Ia-2), A21a− and A21b− each independently represent a monovalent anionic functional group. Each of the monovalent anionic functional groups represented by A21a− and A21b− means a monovalent group including the above-described anionic moiety A1−. No particular limitation is imposed on the monovalent anionic functional groups represented by A21a− and A21b−, but A21a− and A21b− are each, for example, a monovalent anionic functional group selected from the group consisting of formulas (AX-1) to (AX-3) described above.
A22− represents a divalent anionic functional group. The divalent anionic functional group represented by A22− means a divalent groups including the anionic moiety A2 described above. Examples of the divalent anionic functional group represented by A22− include divalent anionic functional groups represented by the following formulas (BX-8) to (BX-11).
M21a+, M21b+, and M22+ each independently represent an organic cation. The definitions of the organic cations represented by M21a+, M21b+, and M22+ are the same as that of M1+ described above, and their preferred modes are also the same as those of M11+.
L21 and L22 each independently represent a divalent organic group.
In a compound PIa-2 formed by replacing each of the organic cations represented by M21a+, M21b+, and M22+ in formula (Ia-2) with H+, the acid dissociation constant a2 derived from an acidic moiety represented by A22H is larger than the acid dissociation constant a1-1 derived from an acidic moiety represented by A21aH and the acid dissociation constant a1-2 derived from an acidic moiety represented by A21bH. The acid dissociation constant a1-1 and the acid dissociation constant a1-2 each correspond to the acid dissociation constant a1 described above. A21a− and A21− may be the same or different. M21a+, M21+, and M22+ may be the same or different.
At least one of M21a+, M21+, M22+, A21a−, A21b−, L21, or L22 may have an acid-decomposable group as a substituent.
In formula (Ia-3), A31a− and A32− each independently represent a monovalent anionic functional group. The definition of the monovalent anionic functional group represented by A31a− is the same as those of A21a− and A21b− in formula (Ia-2), and its preferred mode is also the same as those of A21a− and A21b−.
The monovalent anionic functional group represented by A32− means a monovalent group including the anionic moiety A2− described above. No particular limitation is imposed on the monovalent anionic functional group represented by A32−, and A32− is, for example, a monovalent anionic functional group selected from the group consisting of formulas (BX-1) to (BX-7) described above.
A31− represents a divalent anionic functional group. The divalent anionic functional group represented by A31b− means a divalent group including the anionic moiety A1− described above. Examples of the divalent anionic functional group represented by A31− include a divalent anionic functional group represented by the following formula (AX-4).
M31a+, M31b+, and M32+ each independently represent a monovalent organic cation. The definitions of the organic cations represented by M31a+, M31b+, and M32+ are the same are that of M11+ described above, and their preferred modes are also the same as that of M1+.
L31 and L32 each independently represent a divalent organic group.
In a compound PIa-3 formed by replacing each of the organic cations represented by M31a+, M31b+, and M32+ in formula (Ia-3) with H+, the acid dissociation constant a2 derived from an acidic moiety represented by A32H is larger than the acid dissociation constant a1-3 derived from an acidic moiety represented by A31aH and the acid dissociation constant a1-4 derived from an acidic moiety represented by A31bH. The acid dissociation constant a1-3 and the acid dissociation constant a1-4 each correspond to the acid dissociation constant a1 described above.
A31a− and A32− may be the same or different. M31a+. M31b+, and M32+ may be the same or different.
At least one of M31a+, M31b+, M32+, A31a−, A32−, L31, or L32 may have an acid-decomposable group as a substituent.
In formula (Ia-4), A41a−, A41−, and A42− each independently represent a monovalent anionic functional group. The definitions of the monovalent anionic functional groups represented by A41a− and A41b− are the same as the definitions of A21a− and A21b− in formula (Ia-2) described above. The definition of the monovalent anionic functional group represented by A42− is the same as that of A32− in formula (Ia-3) described above, and its preferred mode is also the same as that of A32−.
M41a+, M41b+, and M42+ each independently represent an organic cation.
L41 represents a trivalent organic group.
In a compound PIa-4 formed by replacing each of the organic cations represented by M41a+, M41b+, and M42+ in formula (Ia-4) with H+, the acid dissociation constant a2 derived from an acidic moiety represented by A42H is larger than the acid dissociation constant a1-5 derived from an acidic moiety represented by A41aH and the acid dissociation constant a1-6 derived from an acidic moiety represented by A41bH. The acid dissociation constant a1-5 and the acid dissociation constant a1-6 each correspond to the acid dissociation constant a1 described above.
A41a−, A41b−, and A42− may be the same or different. M41a+, M41b+, and M42+ may be the same or different.
At least one of M41a+, M41b+, M42+, A41a−, A41b−, A42−, or L41 may have an acid-decomposable group as a substituent.
No particular limitation is imposed on the divalent organic groups represented by L21 and L22 in In formula (Ia-2) and L31 and L32 in formula (Ia-3), and examples thereof include —CO—, —NR—, —O—, —S—, —SO—, —SO2—, alkylene groups (which may be linear or branched and have preferably 1 to 6 carbon atoms), cycloalkylene groups (having preferably 3 to 15 carbon atoms), alkenylene groups (having preferably 2 to 6 carbon atoms), divalent aliphatic heterocyclic groups (preferably 5- to 10-membered rings, more preferably 5- to 7-membered rings, and still more preferably 5- to 6-membered rings, each of which has at least one N atom, 0 atom, S atom, or Se atom in the ring structure), divalent aromatic heterocyclic groups (preferably 5- to 10-membered rings, more preferably 5- to 7-membered rings, and still more preferably 5- to 6-membered rings, each of which has at least one N atom, 0 atom, S atom, or Se atom in the ring structure), divalent aromatic hydrocarbon ring groups (preferably 6- to 10-membered rings and more preferably 6-membered rings), and divalent organic groups formed by combining a plurality of groups selected from the above groups. Examples of R include a hydrogen atom and monovalent organic groups. No particular limitation is imposed on the monovalent organic group, but the monovalent organic group is, for example, preferably an alkyl group (having preferably 1 to 6 carbon atoms).
The alkylene, cycloalkylene, alkenylene, divalent aliphatic heterocyclic, divalent aromatic heterocyclic, and divalent aromatic hydrocarbon ring groups described above may each have a substituent. Examples of the substituent include halogen atoms (preferably a fluorine atom).
Preferably, the divalent organic groups represented by L21 and L22 in formula (Ia-2) and L31 and L32 in formula (Ia-3) are each, for example, a divalent organic group represented by formula (L2) below.
In formula (L2), q represents an integer of from 1 to 3. * represents a bonding position.
Xfs each independently represent a fluorine atom or an alkyl group substituted with at least one fluorine atom. The number of carbon atoms in the alkyl group is preferably 1 to 10 and more preferably 1 to 4. The alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group.
Xfs are each preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms and more preferably a fluorine atom or CF3. In particular, it is more preferable that both Xf's are fluorine atoms.
LA represents a single bond or a divalent linking group.
No particular limitation is imposed on the divalent linking group represented by LA, and examples thereof include —CO—, —O—, —SO—, —SO2—, alkylene groups (which may be linear or branched and have preferably 1 to 6 carbon atoms), cycloalkylene groups (having preferably 3 to 15 carbon atoms), divalent aromatic hydrocarbon ring groups (preferably 6- to 10-membered rings and more preferably 6-membered rings), and divalent linking groups formed by combining a plurality of groups selected from the above groups.
The alkylene, cycloalkylene, and divalent aromatic hydrocarbon ring groups described above may each have a substituent. Examples of the substituent include halogen atoms (preferably a fluorine atom).
Examples of the divalent organic group represented by formula (L2) include *—CF2—*, *—CF2—CF2—*, *—CF2—CF2—CF2—*, *-Ph-O—SO2—CF2—*, *-Ph-O—SO2—CF2—CF2—*, *-Ph-O—SO2—CF2—CF2—CF2—*, and *-Ph-OCO—CF2—*. Ph is a phenylene group optionally having a substituent and is preferably a 1,4-phenylene group. No particular limitation is imposed on the substituent, but the substituent is preferably an alkyl group (for example, having preferably 1 to 10 carbon atoms and more preferably 1 to 6 carbon atoms), an alkoxy group (for example, having preferably 1 to 10 carbon atoms and more preferably 1 to 6 carbon atoms), or an alkoxycarbonyl group (for example, having preferably 2 to 10 carbon atoms and more preferably 2 to 6 carbon atoms).
When L21 and L22 in formula (Ia-2) each represent the divalent organic group represented by formula (L2), it is preferable that the direct bond (*) on the LA side in formula (L2) is bonded to A21a− or A21b− in formula (Ia-2).
When L31 and L32 in formula (Ia-3) each represent the divalent organic group represented by formula (L2), it is preferable that the direct bond (*) on the LA side in formula (L2) is bonded to A31a− or A32− in formula (Ia-3).
Next, formula (Ia-5) will be described.
In formula (Ia-5), A51a−, A51b−, and A51c− each independently represent a monovalent anionic functional group. Each of the monovalent anionic functional groups represented by A51a−, A51b−, and A51c− means a monovalent group including the anionic moiety A1− described above. No particular limitation is imposed on the monovalent anionic functional groups represented by A51a−, A51b−, and A51c−, but each of these monovalent anionic functional groups is, for example, a monovalent anionic functional group selected from the group consisting of formulas (AX-1) to (AX-3) described above.
A52a− and A52b− each represent a divalent anionic functional group. Each of the divalent anionic functional groups represented by A52a− and A52b− means a divalent group including the anionic moiety A2 described above. The divalent anionic functional groups represented by A52a− and A52b− are each is, for example, a divalent anionic functional groups selected from the group consisting of formulas (BX-8) to (BX-11) described above.
M51a+, M51b+, M51c+, M52a+, and M52b+ each independently represent an organic cation. The definitions of the organic cations represented by M51a+, M51b+, M51c+, M52a+, and M52b+ are the same as the definition of M11+ described above, and their preferred modes are also the same as that of M1+.
L51 and L53 each independently represent a divalent organic group. The definitions of the divalent organic groups represented by L51 and L53 are the same as those of L21 and L22 in formula (Ia-2) described above, and their preferred modes are also the same as those of L21 and L22.
L52 represents a trivalent organic group. The definition of the trivalent organic group represented by L52 is the same as that of L41 in formula (Ia-4) described above, and its preferred mode is also the same as that of L41.
In a compound PIa-5 formed by replacing each of the organic cations represented by M51a+, M51b+, M51c+, M52a+, and M52b+ in formula (Ia-5) with H+, the acid dissociation constant a2-1 derived from an acidic moiety represented by A52aH and the acid dissociation constant a2-2 derived from an acidic moiety represented by A52bH are larger than the acid dissociation constant a1-1 derived from an acidic moiety represented by A51aH, the acid dissociation constant a1-2 derived from an acidic moiety represented by A51bH, and the acid dissociation constant a1-3 derived from an acidic moiety represented by A51cH. The acid dissociation constants a1-1 to a1-3 each correspond to the acid dissociation constant a1 described above, and the acid dissociation constants a2-1 and a2-2 each correspond to the acid dissociation constant a2 described above.
A51a−, A51b−, and A51c− may be the same or different. A52a− and A52b− may be the same or different. M51a+, M51b+, M51c+, M52a+, and M52b+ may be the same or different.
At least one of M51+, M51c+, M52a+, M52b+, A51a−, A51b−, A51c−, L51, L52, or L53 may have an acid-decomposable group as a substituent.
The compound (II) is a compound that has two or more structural moieties X described above and at least one structural moiety Z described below and is a compound that generates an acid including two or more first acidic moieties derived from the structural moieties X and the structural moiety Z when irradiated with actinic rays or radiation.
Structural moiety Z: Non-ionic moiety capable of neutralizing acid
The definition of the structural moiety X in the compound (II) and the definitions of A1− and M1+ are the same as that of the structural moiety X in the compound (I) described above and those of A1− and M1+ in the structural moiety X in the compound (I) described above, and their preferred modes are also the same as those of the compound (I).
In a compound PIT formed by replacing each of the cationic moieties M1+ in the structural moieties X in the compound (II) with H+, a preferred range of the acid dissociation constant a1 derived from an acidic moiety represented by HA1 formed by replacing the cationic moiety M1+ in one of the structural moieties X with H+ is the same as that of the acid dissociation constant a1 in the compound PI.
When the compound (II) is, for example, a compound that generates an acid having two first acidic moieties derived from the structural moieties X and the structural moiety Z, the compound PII corresponds to a “compound having two HA1s.” When the acid dissociation constants of the compound PIT are determined, the acid dissociation constant when the compound PI becomes a “compound having one A1− and one HA1” and the dissociation constant when the “compound having one A1− and one HA1” becomes a “compound having two A1−'s” each correspond to the acid dissociation constant a1.
The acid dissociation constant a1 is determined by the acid dissociation constant measurement method described above.
The compound PI corresponds to an acid generated when the compound (II) is irradiated with actinic rays or radiation.
The two or more structural moieties X may be the same or different. The two or more A1−'s may be the same or different, and the two or more M1+'s may be the same or different.
No particular limitation is imposed on the non-ionic moiety that is in the structural moiety Z and capable of neutralizing an acid, and the non-ionic moiety is, for example, preferably a moiety including a functional group having an electron or a group capable of electrostatically interacting with a proton.
Examples of the functional group having an electron or a group capable of electrostatically interacting with a proton include a functional group having a macrocyclic structure such as a cyclic polyether and a functional group having a nitrogen atom having an unshared electron pair not contributing to π-conjugation. The nitrogen atom having an unshared electron pair not contributing to π-conjugation is, for example, a nitrogen atom having a partial structure represented by any of the following formulas.
Examples of the partial structure of the functional group having an electron or a group capable of electrostatically interacting with a proton include crown ether structures, azacrown ether structures, primary to tertiary amine structures, a pyridine structure, an imidazole structure, and a pyrazine structure. Of these, primary to tertiary amine structures are preferred.
No particular limitation is imposed on the compound (II), and examples thereof include compounds represented by the following formulas (IIa-1) and (IIa-2).
In formula (IIa-1), the definitions of A61a− and A61b− are each the same as that of A11− in formula (Ia-1) above, and their preferred modes are also the same as that of A11-. The definitions of M61a+ and M61b+ are each the same as that of M11+ in formula (Ia-1), and their preferred modes are also the same as that of M11+.
In formula (IIa-1), the definitions of L61 and L62 are each the same as that of L1 in formula (Ia-1) above, and their preferred modes are also the same as that of L1.
In formula (IIa-1), R2X represents a monovalent organic group. No particular limitation is imposed on the monovalent organic group represented by R2X, and examples thereof include alkyl groups (which have preferably 1 to 10 carbon atoms and may be linear or branched), cycloalkyl groups (having preferably 3 to 15 carbon atoms), and alkenyl groups (having preferably 2 to 6 carbon atoms). In these groups, —CH2— may be replaced with one or a combination of two or more selected from the group consisting of —CO—, —NH—, —O—, —S—, —SO—, and —SO2—.
The above alkyl, cycloalkyl, and alkenyl groups may each have a substituent. No particular limitation is imposed on the substituent, and examples thereof include halogen atoms (preferably a fluorine atom).
In a compound PIIa-1 formed by replacing each of the organic cations represented by M61a+ and M61b+ in formula (IIa-1) with H+, the acid dissociation constant a1-7 derived from an acidic moiety represented by A61aH and the acid dissociation constant a1-8 derived from an acidic moiety represented by A61bH each correspond to the acid dissociation constant a1 described above.
The compound PIIa-1 formed by replacing each of the cationic moieties M61a+ and M61b+ in the structural moieties X in formula (IIa-1) with H+ corresponds to HA61a-L61-N(R2X)-L62-A61bH. The compound PIIa-1 is the same as the acid generated from the compound represented by formula (IIa-1) upon irradiation with actinic rays or radiation.
At least one of M61a+, M61b+, A61a−, A61b−, L61, L62, or R2X may have an acid-decomposable group as a substituent.
The definitions of A71a−, A71b−, and A71c− in formula (IIa-2) are each the same as that of A11− in formula (Ia-1) above, and their preferred modes are also the same as that of A1−. The definitions of M71a+, M71b+, and M71c+ are each the same as that of M11+ in formula (Ia-1), and their preferred modes are also the same as that of M11+.
The definitions of L71, L72, and L73 in formula (IIa-2) are each the same as that of L1 in formula (Ia-1) above, and their preferred modes are also the same as that of L1.
In a compound PIIa-2 formed by replacing each of the organic cations represented by M71a+, M71b+, and M71c+ in formula (IIa-2) with H+, the acid dissociation constant a1-9 derived from an acidic moiety represented by A71aH, the acid dissociation constant a1-10 derived from an acidic moiety represented by A71bH, and the acid dissociation constant a1-11 derived from an acidic moiety represented by A71cH each correspond to the acid dissociation constant a1 described above.
The compound PIIa-2 formed by replacing each of the cationic moieties M71a+, M71b+, and M71c+ in the structural moieties X in formula (IIa-1) with H+ corresponds to HA71aL71-N(L73-A71cH)-L72-A71bH. The compound PIIa-2 is the same as the acid generated from the compound represented by formula (IIa-2) upon irradiation with actinic rays or radiation.
At least one of M71a+, M71b+, M71c+, A71a−, A71b−, A71c−, L71, L72, or L73 may have an acid-decomposable group as a substituent.
Examples of the anionic moiety that the compound (I) and the compound (II) can have are shown below, but the invention is not limited thereto.
Preferred examples of the compound (B) used include photoacid generators disclosed in paragraphs [0135] to [0171] of WO2018/193954A, paragraphs [0077] to [0116] of WO2020/066824A, and paragraphs [0018] to [0075] and [0334] to [0335] of WO2017/154345A.
No particular limitation is imposed on the content of the compound (B) in the resist composition. From the viewpoint of allowing the pattern formed to have a sharper rectangular cross-sectional shape, the content of the compound (B) with respect to the total amount of the solids in the resist composition is preferably 1% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more. The content of the compound (B) with respect to the total amount of the solids in the resist composition is preferably 80% by mass or less, more preferably 70% by mass or less, and still more preferably 60% by mass or less.
One compound (B) may be used alone, or two or more compounds (B) may be used.
The compound (B) may be the following compound (X).
The compound (X) is a salt including a cation (specific cation) represented by the following formula (X).
In formula (X), ArX represents an aryl group substituted with a group including a halogen atom.
The aryl group represented by ArX may be a monocyclic or polycyclic aryl group. The aryl group may be a heterocycle including an oxygen atom, a nitrogen atom, a sulfur atom, etc.
Examples of the heterocycle include a pyrrole ring, a furan ring, a thiophene ring, an indole ring, a benzofuran ring, and a benzothiophene ring.
The number of carbon atoms in the aryl group (the number of carbon atoms in ArX) is preferably 6 to 20, more preferably 6 to 15, and still more preferably 6 to 10.
The group including a halogen atom means a halogen atom itself and a group including a halogen atom as a part of a substituent.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and the halogen atom is preferably a fluorine atom or an iodine atom.
Examples of the group including a halogen atom include halogen atoms, halogenated alkyl groups, halogenated alkoxy groups, and halogenated aryl groups.
The number of halogen atoms included in the aryl group is preferably 1 to 20, more preferably 1 to 15, and still more preferably 1 to 10.
The number of halogen atom-containing groups included in the aryl group is preferably 1 to 10, more preferably 1 to 5, and still more preferably 1 to 3.
The aryl group may be substituted with, in addition to the group including a halogen atom, a group including no halogen atom. The group including no halogen atom is preferably an alkyl group (having preferably 1 to 6 carbon atoms), an alkoxy group, or an alkoxycarbonyl group and more preferably an alkyl group (having preferably 1 to 6 carbon atoms) or an alkoxy group (having preferably 1 to 6 carbon atoms).
The aryl group is preferably a phenyl group or a naphthyl group and more preferably a phenyl group.
RX11 to RX16 each independently represent a hydrogen atom or a hydrocarbon group.
At least one of RX11 or RX12 represents preferably a hydrocarbon group. Preferably, RX13 to RX16 each represent a hydrogen atom.
The hydrocarbon group may be a linear, branched, or cyclic hydrocarbon group.
Examples of the hydrocarbon group include alkyl groups, cycloalkyl groups, alkenyl groups, and aryl groups, and the hydrocarbon group is preferably an alkyl group.
The number of carbon atoms in the hydrocarbon group is preferably 1 to 20, more preferably 1 to 10, and still more preferably 1 to 5.
RX11 and RX12 may be bonded together to form a ring. RX11 and at least one of RX13, RX14, RX15, or RX16 or RX12 and at least one of RX13, RX14, RX15, or RX16 may be bonded together to form a ring.
n and m each independently represent an integer of 1 or more.
n and m are each preferably 1 to 10, more preferably 1 to 5, still more preferably 1 to 3, and particularly preferably 2. Preferably, n and m represent the same integer.
When n represents an integer of 2 or more, two or more RX13's may be the same or different, and two or more RX14's may be the same or different. When m represents an integer of 2 or more, two or more RX15's may be the same or different, and two or more RX16's may be the same or different.
Lx represents a divalent linking group.
Examples of the divalent linking group include —CO—, —NRA—, —O—, —S—, —SO—, —SO2—, —N(SO2-RA)—, alkylene groups, cycloalkylene groups, alkenylene groups, and divalent linking groups formed by combining any of these groups. The divalent linking group is preferably a divalent linking group including an oxygen atom.
Examples of the divalent linking group including an oxygen atom include —CO—, —O—, —SO—, —SO2—, —N(SO2—RA)—, and divalent linking groups formed by combining any of these groups. Examples of RA include a hydrogen atom and alkyl groups having 1 to 6 carbon atoms.
In particular, the divalent linking group including an oxygen atom is preferably —O—, —CO—, or —N(SO2—RA)— and more preferably —O— or —CO—.
The divalent linking group including an oxygen atom means an oxygen atom itself and a divalent linking group including an oxygen atom as a part thereof.
The number of oxygen atoms included in the oxygen atom-containing divalent linking group is preferably 1 to 3, more preferably 1 to 2, and still more preferably 1.
The specific cation is preferably a cation represented by formula (X-1).
In formula (X-1), X1 represents a group including a halogen atom.
X1 in formula (X) above has the same meaning as that of the halogen atom-containing group included in ArX, and its preferred ranges are also the same as those of the halogen atom-containing group included in ArX.
Y1 represents a group including no halogen atom.
The group including no halogen atom is preferably an alkyl group (having preferably 1 to 6 carbon atoms), an alkoxy group, or an alkoxycarbonyl group and more preferably an alkyl group (having preferably 1 to 6 carbon atoms) or an alkoxy group.
The group including no halogen atom means a group including no halogen atom as a part of a substituent. Specifically, Y1 represents a group other than the halogen atom-containing group represented by X1.
a represents an integer of 1 to 5, and b represents an integer of 0 to 4. a+b is 1 to 5.
a is preferably 1 to 4. b is preferably 1 to 4.
RX20 to RX29 each independently represent a hydrogen atom or a hydrocarbon group.
RX20 to RX21 have the same meanings as those of RX11 to RX12 in formula (X) above, and their preferred ranges are also the same as those of RX11 to RX12 in formula (X).
The hydrocarbon group represented by each of RX22 to RX29 may be a linear, branched, or cyclic hydrocarbon group.
Examples of the hydrocarbon group represented by each of RX22 to RX29 include alkyl groups, cycloalkyl groups, alkenyl groups, and aryl groups, and the hydrocarbon group is preferably an alkyl group.
The number of carbon atoms in the hydrocarbon group represented by each of RX22 to RX29 is preferably 1 to 20, more preferably 1 to 10, and still more preferably 1 to 5. RX20 and RX21 may be bonded together to form a ring. RX20 and at least one of RX22, RX23, RX24, or RX25 or RX21 and at least one of RX26, RX27, RX28, or RX29 may be bonded together to form a ring.
One specific cation may be used alone, or two or more specific cations may be used.
The molecular weight of the compound (X) is preferably 100 to 10000, more preferably 100 to 2500, and still more preferably 100 to 1500.
A preferred range of the content of the compound (X) is the same as the preferred range of the content of the compound (B).
One compound (X) may be used alone, or two or more compounds (X) may be used. When two or more compounds (X) are used, it is preferable that the total content falls within the preferred range described above.
Specific examples of the compound (X) are shown below, but the invention is not limited thereto.
The resist composition may include an acid diffusion control agent.
The acid diffusion control agent functions as a quencher that traps the acid generated from the photoacid generator etc. during exposure to light to thereby suppress the reaction of the acid decomposable resin with an excess portion of the generated acid in unexposed portions.
Examples of the acid diffusion control agent include a basic compound (CA), a low-molecular weight compound (CB) having a nitrogen atom and having a group that leaves by the action of an acid, and a compound (CC) whose acid diffusion control ability decreases or disappears when the compound (CC) is irradiated with actinic rays or radiation.
Examples of the compound (CC) include an onium salt compound (CD) that serves as a weak acid weaker than the photoacid generator and a basic compound (CE) whose basicity decreases or disappears upon irradiation with actinic rays or radiation.
The acid diffusion control agent used may be an appropriate well-known acid diffusion control agent.
For example, known compounds disclosed in paragraphs [0627] to [0664] of US2016/0070167A, paragraphs [0095] to [0187] of US2015/0004544A, paragraphs [0403] to [0423] of US2016/0237190A, and paragraphs [0259] to [0328] of US2016/0274458A can be preferably used as the acid diffusion control agent.
Specific examples of the basic compound (CA) include those described in paragraphs [0132] to [0136] of WO2020/066824A, and specific examples of the basic compound (CE) whose basicity decreases or disappears upon irradiation with actinic rays or radiation include those described in paragraphs [0137] to [0155] of WO2020/066824A. Specific examples of the low-molecular weight compound (CB) having a nitrogen atom and having a group that leaves by the action of an acid include those described in paragraphs [0156] to [0163] of WO2020/066824A, and specific examples of an onium salt compound (CE) that has a nitrogen atom in its cationic moiety include those described in paragraph [0164] of WO2020/066824A.
Specific examples of the onium salt compound (CD) that serves as a weak acid weaker than the photoacid generator include those described in paragraphs [0305] to [0314] of WO2020/158337A, paragraphs [0455] to [0464] of WO2020/158467A, paragraphs [0298] to [0307] of WO2020/158366A, and paragraphs [0357] to [0366] of WO2020/158417A.
When the resist composition includes the acid diffusion control agent, the content of the acid diffusion control agent (the total content when a plurality of acid diffusion control agents are present) with respect to the total amount of the solids in the composition is preferably 0.1 to 15.0% by mass and more preferably 1.0 to 15.0% by mass.
In the resist composition, one acid diffusion control agent may be used alone, or two or more acid diffusion control agents may be used.
The resist composition may further include, in addition to the resin (A), a resin different from the resin (A). The resin different from the resin (A) is referred to also as a “resin (D).”
Preferably, the resin (D) is a hydrophobic resin.
Preferably, the hydrophobic resin is designed so as to segregate on the surface of a resist film. However, it is not always necessary that, unlike a surfactant, the hydrophobic resin have a hydrophilic group in its molecule and contribute to uniform mixing of polar and nonpolar substances.
The effects of the addition of the hydrophobic resin include control of the static and dynamic contact angles of water on the surface of the resist film and reduction of outgassing.
From the viewpoint of segregation of the hydrophobic resin in a surface layer of the film, the hydrophobic resin has preferably at least one of a fluorine atom, a silicon atom, or a CH3 partial structure included in a side chain portion of the resin and has more preferably two or more of them. Preferably, the hydrophobic resin has a hydrocarbon group having 5 or more carbon atoms. Each of these groups may be present as a substituent in the main chain of the resin or its side chain.
Examples of the hydrophobic resin include compounds described in paragraphs [0275] to [0279] of WO2020/004306A.
When the resist composition includes the resin (D), the content of the resin (D) with respect to the total amount of the solids in the resist composition is preferably 0.01 to 20.0% by mass and more preferably 0.1 to 15.0% by mass.
The resist composition may include a surfactant. When the surfactant is included, the compound has better adhesiveness, and a pattern with fewer development defects can be formed.
The surfactant is preferably a fluorine-based surfactant and/or a silicon-based surfactant.
Examples of the fluorine-based surfactant and/or the silicon-based surfactant include surfactants disclosed in paragraphs [0218] and [0219] of WO2018/19395A.
One of these surfactants may be used alone, or two or more of them may be used.
When the resist composition includes the surfactant, the content of the surfactant with respect to the total amount of the solids in the composition is preferably 0.0001 to 2.0% by mass, more preferably 0.0005 to 1.0% by mass, and still more preferably 0.1 to 1.0% by mass.
[Additional additives]
The resist composition may further include a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and/or a compound capable of increasing the solubility in a developer (such as a phenol compound having a molecular weight of 1000 or less or an alicyclic or aliphatic compound including a carboxy group).
The resist composition may further include a dissolution inhibiting compound. The “dissolution inhibiting compound” is a compound that has a molecular weight of 3000 or less and is decomposed by the action of an acid to cause the degree of solubility of the resist composition in an organic-based developer to decrease.
The resist composition is preferably used as a photosensitive composition for EBs or a photosensitive composition for EUV.
The wavelength of the EUV is 13.5 nm and is shorter than the wavelength of ArF light (wavelength: 193 nm) etc., and the number of incident photons when light exposure is performed at the same sensitivity is smaller. Therefore, the influence of “photon shot noise,” i.e., stochastic variations in the number of photons, is large, and this causes an increase in LER and bridge defects. One method to reduce the photon shot noise is to increase the exposure value to increase the number of incident photons, but there is a trade-off with a demand for higher sensitivity.
When the value of A determined by formula (1) is large, the efficiency of absorption of EUV and electron beams by a resist film formed by the resist composition is high, and this is effective in reducing the photon shot noise. The value of A means the efficiency of absorption of EUV and electron beams by a resist film having a specific mass ratio.
The value of A is preferably 0.120 or more. No particular limitation is imposed on the upper limit of the value of A. However, if the value of A is excessively large, the EUV and electron beam transmittance of the resist film decreases, and the profile of an optical image in the resist film deteriorates, so that a good pattern shape is unlikely to be obtained. Therefore, the value of A is preferably 0.240 or less and more preferably 0.220 or less.
In formula (1), [H] represents the molar ratio of hydrogen atoms derived from the total solids in the actinic ray-sensitive or radiation-sensitive resin composition with respect to all the atoms in the total solids, and [C] represents the molar ratio of carbon atoms derived from the total solids in the actinic ray-sensitive or radiation-sensitive resin composition with respect to all the atoms in the total solids. [N] represents the molar ratio of nitrogen atoms derived from the total solids in the actinic ray-sensitive or radiation-sensitive resin composition with respect to all the atoms in the total solids, and [O] represents the molar ratio of oxygen atoms derived from the total solids in the actinic ray-sensitive or radiation-sensitive resin composition with respect to all the atoms in the total solids. [F] represents the molar ratio of fluorine atoms derived from the total solids in the actinic ray-sensitive or radiation-sensitive resin composition with respect to all the atoms in the total solids, and [S] represents the molar ratio of sulfur atoms derived from the total solids in the actinic ray-sensitive or radiation-sensitive resin composition with respect to all the atoms in the total solids. [I] represents the molar ratio of iodine atoms derived from the total solids in the actinic ray-sensitive or radiation-sensitive resin composition with respect to all the atoms in the total solids.
For example, when the resist composition includes a resin whose polarity increases by the action of an acid (acid-decomposable resin), the photoacid generator, the acid diffusion control agent, and the solvent, the above resin, the photoacid generator, and the acid diffusion control agent correspond to the solids. Specifically, all the atoms in the total solids correspond to the sum of all the atoms derived from the resin, all the atoms derived from the photoacid generator, and all the atoms derived from the acid diffusion control agent. For example, [H] represents the molar ratio of hydrogen atoms derived from the total solids with respect to all the atoms in the total solids. In the above example, [H] represents the total molar ratio of hydrogen atoms derived from the above resin, hydrogen atoms derived from the photoacid generator, and hydrogen atoms derived from the acid diffusion control agent with respect to the sum of all the atoms derived from the above resin, all the atoms derived from the photoacid generator, and all the atoms derived from the acid diffusion control agent.
When the structures of the constituent components of the total solids in the resist composition and their contents are known, the value of A can be computed by computing the ratio of the numbers of atoms included in the composition. Even when the constituent components are unknown, the ratio of the numbers of constituent atoms can be computed by subjecting a resist film obtained by evaporating the solvent component in the resist composition to an analytical method such as elemental analysis.
[Method for manufacturing actinic ray-sensitive or radiation-sensitive resin composition]
Preferably, a method for manufacturing the actinic ray-sensitive or radiation-sensitive resin composition of the invention includes the step of adding a solution of the resin (A) to a poor solvent including the organic solvent (Y) to cause the resin (A) to precipitate (this step is hereinafter referred to also as “step (X).”
By performing step (X), the resin (A) can be purified. Monomers used to synthesize the resin (A) include a monomer having a pentafluorosulfanyl group. In step (X), the poor solvent including the organic solvent is used in order to cause the resin (A) to precipitate to thereby separate the resin (A) from remaining monomers, and the resin (A) is thereby purified.
The poor solvent may be composed only of the organic solvent (Y) or may include the organic solvent (Y) and another solvent.
The poor solvent may include only one organic solvent (Y) or may include two or more organic solvents (Y).
Specific examples of the organic solvent (Y) (their compound names and C log P values) are shown below, but the organic solvent (Y) is not limited thereto.
The C log P value of the organic solvent (Y) is preferably 1.4 or more.
The C log P value used is a value computed using Chem Draw Professional (version: 16.0.1.4(77) manufactured by ParkinElmer Informatics, Inc.).
[Actinic ray-sensitive or radiation-sensitive film]
The actinic ray-sensitive or radiation-sensitive film of the invention is an actinic ray-sensitive or radiation-sensitive film formed using the above-described actinic ray-sensitive or radiation-sensitive resin composition of the invention.
The actinic ray-sensitive or radiation-sensitive film is typically a resist film.
[Pattern forming method]
The pattern forming method of the invention is a pattern forming method including:
The procedure of each of the steps will next be described in detail.
Step (1) is the step of forming an actinic ray-sensitive or radiation-sensitive film (which may be referred to also as a “resist film”) using the above-described actinic ray-sensitive or radiation-sensitive resin composition (resist composition) of the invention.
Preferably, the resist composition used in step (1) includes the acid-decomposable resin and the photoacid generator.
Step (1) is typically the step of forming the resist film on a substrate using the resist composition.
Examples of the method for forming a resist film on a substrate using the resist composition include a method in which the resist composition is applied to the substrate.
Preferably, the resist composition is filtrated through a filter before the application as needed. The pore size of the filter is preferably 0.1 m or less, more preferably 0.05 m or less, and still more preferably 0.03 m or less. The filer is preferably a polytetrafluoroethylene-made filter, a polyethylene-made filter, or a nylon-made filter.
The resist composition can be applied to a substrate (e.g., a silicon substrate or a silicon dioxide coating) used for production of an integrated circuit element using an appropriate application method using a spinner, a coater, etc. The application method is preferably spin coating using a spinner. The number or revolutions when the spin coating using a spinner is performed is preferably 1000 to 3000 rpm (rotations per minute).
After the application of the resist composition, the substrate may be dried to thereby form the resist film. If necessary, an undercoat film (an inorganic film, an organic film, or an antireflection film) may be formed as an underlayer of the resist film.
Examples of the drying method include a method in which the substrate is heated and dried. The heating may be performed using heating means included in an ordinary exposing device and/or an ordinary developing device or may be performed using a hot plate etc. The heating temperature is preferably 80 to 150° C., more preferably 80 to 140° C., and still more preferably 80 to 130° C. The heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, and still more preferably 60 to 600 seconds.
No particular limitation is imposed on the film thickness of the resist film, but the film thickness is preferably 10 to 120 nm because a finer pattern can be formed with higher accuracy. In particular, when the resist film is exposed to EUV light, the film thickness of the resist film is more preferably 10 to 65 nm and still more preferably 15 to 50 nm. When ArF liquid immersion exposure is performed, the film thickness of the resist film is more preferably 10 to 120 nm and still more preferably 15 to 90 nm.
A topcoat may be formed on the resist film using a topcoat composition.
It is preferable that the topcoat composition is immiscible with the resist film and can be uniformly applied to the upper surface of the resist film. No particular limitation is imposed on the topcoat, and a well-known topcoat can be formed using a well-known method. For example, the topcoat can be formed using a method described in paragraphs [0072] to [0082] of JP2014-059543A.
It is preferable, for example, that a topcoat including a basic compound described in JP2013-61648A is formed on the resist film. Specific examples of the basic compound that can be included in the topcoat include basic compounds that can be included in the resist composition.
It is also preferable that the topcoat includes a compound including at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxy group, a thiol group, a carbonyl bond, and an ester bond.
Step 2 is the step of exposing the resist film to light.
Examples of the light exposure method include a method in which the resist film formed is irradiated with actinic rays or radiation through a prescribed mask.
Examples of the actinic rays or radiation include infrared rays, visible rays, ultraviolet rays, far-ultraviolet rays, extreme ultraviolet rays, X rays, and electron beams. Actinic rays or radiation having a wavelength of 250 nm or shorter and electron beams are preferred, and actinic rays or radiation having a wavelength of 220 nm or shorter and electron beams are more preferred. Actinic rays or radiation having a wavelength of 1 to 200 nm and electron beams are particularly preferred. Specific examples of the actinic rays or radiation include KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F2 excimer laser light (157 nm), EUV light (13 nm), X rays, and electron beams.
It is preferable to perform baking (heating) after the light exposure but before development. The baking facilitates the reaction in the exposed portions, and the sensitivity and the pattern shape are further improved.
The heating temperature is preferably 80 to 150° C., more preferably 80 to 140° C., and still more preferably 80 to 130° C.
The heating time is preferably 10 to 1000 seconds, more preferably 10 to 180 seconds, and still more preferably 30 to 120 seconds.
The heating may be performed using heating means included in an ordinary exposing device and/or an ordinary developing device or may be performed using a hot plate etc.
This step is referred to as post-exposure baking.
Step 3 is the step of developing the actinic ray-sensitive or radiation-sensitive film (resist film) exposed to light in step (2) with a developer to form a pattern.
The developer may be an alkali developer or may be a developer including an organic solvent (hereinafter referred to also as an organic-based developer).
Examples of the developing method include: a method in which the substrate is dipped into a bath filled with the developer for a prescribed time (a dipping method); a method in which the developer is placed on the surface of the substrate so as to bulge due to surface tension and left to stand for a prescribed time to develop the resist film (a puddle method); a method in which the developer is sprayed onto the surface of the substrate (a spraying method); and a method in which the developer is continuously discharged from a developer discharging nozzle onto the substrate rotating at a constant speed while the developer discharging nozzle is scanned at a constant speed (a dynamic dispensing method).
The step of replacing the solvent with another solvent to stop the development may be performed after the developing step.
No particular limitation is imposed on the developing time so long as the resin in unexposed portions is dissolved sufficiently, and the developing time is preferably 10 to 300 seconds and more preferably 20 to 120 seconds.
The temperature of the developer is preferably 0 to 50° C. and more preferably 15 to 35° C.
The alkali developer used is preferably an aqueous alkali solution including an alkali. No particular limitation is imposed on the type of aqueous alkali solution. Examples of the aqueous alkali solution include aqueous alkali solutions including quaternary ammonium salts typified by tetramethylammonium hydroxide, inorganic alkalis, primary amines, secondary amines, tertiary amines, alcohol amines, cyclic amines, etc. In particular, the alkali developer is preferably an aqueous solution of a quaternary ammonium salt typified by tetramethylammonium hydroxide (TMAH). An appropriate amount of an alcohol, a surfactant, etc. may be added to the alkali developer. The alkali concentration of the alkali developer is generally 0.1% to 20% by mass. The pH of the alkali developer is generally 10.0 to 15.0.
The organic-based developer is preferably a developer including at least one organic solvent selected from the group consisting of ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents.
A mixture of a plurality of solvents selected from the above solvents may be used, or the organic-based developer may be mixed with water or a solvent other that the above solvents. The content of water with respect to the total mass of the developer is preferably less than 50% by mass, more preferably less than 20% by mass, and still more preferably less than 10% by mass, and it is particularly preferable that the developer includes substantially no water.
The content of the organic solvent with respect to the total mass of the organic-based developer is preferably from 50% by mass to 100% by mass inclusive, more preferably from 80% by mass to 100% by mass inclusive, still more preferably from 90% by mass to 100% by mass inclusive, and particularly preferably from 95% by mass to 100% by mass inclusive.
Preferably, the above pattern forming method further includes the step of, after step
(3), washing with a rinsing solution.
Examples of the rinsing solution used in the rinsing step after the step of developing using the alkali developer include pure water. An appropriate amount of a surfactant may be added to the pure water.
An appropriate amount of a surfactant may be added to the rinsing solution.
No particular limitation is imposed on the rinsing solution used for the rinsing step after the step of developing using the alkali developer so long as the rinsing solution does not dissolve the pattern, and a solution including a general-purpose organic solvent can be used. Preferably, the rinsing solution used includes at least one organic solvent selected from the group consisting of hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, and ether-based solvents.
No particular limitation is imposed on the method for the rinsing step, and examples thereof include: a method in which the rinsing solution is continuously discharged onto the substrate rotating at a constant speed (a spin coating method); a method in which the substrate is dipped into a bath filled with the rinsing solution for a prescribed time (a dipping method); and a method in which the rinsing solution is sprayed onto the surface of the substrate (a spraying method).
The pattern forming method of the invention may further include a heating (post-baking) step after the rinsing step. Through this step, the developer and the rinsing solution remaining between traces of the pattern and inside the pattern are removed by baking. Through this step, the resist pattern is annealed, and the effect of improving surface roughness of the pattern is obtained. The heating step after the rinsing step is performed at generally 40 to 250° C. (preferably 90 to 200° C.) for generally 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).
The pattern formed may be used as a mask to perform etching treatment on the substrate. Specifically, the pattern formed in step (3) may be used as a mask to process the substrate (or the underlayer film and the substrate) to thereby form a pattern on the substrate.
No particular limitation is imposed on the method for processing the substrate (or the underlayer film and the substrate). It is preferable that the pattern formed in step 3 is used as a mask and the substrate (or the underlayer film and the substrate) is dry-etched to form a pattern on the substrate. The dry etching is preferably oxygen plasma etching.
Preferably, the resist composition and other various materials (such as the solvent, the developer, the rinsing solution, a composition for forming an antireflection film, and the composition for forming the topcoat) used in the pattern forming method include no impurities such as metals. The content of the impurities included in each of these materials is preferably 1 ppm (parts per million) by mass or less, more preferably 10 ppb (parts per billion) by mass or less, still more preferably 100 ppt (parts per trillion) by mass or less, particularly preferably 10 ppt by mass or less, and most preferably 1 ppt by mass or less. No particular limitation is imposed on the lower limit of the content of the impurities, and the content is preferably 0 ppt by mass or more. Examples of the metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn.
Examples of a method for removing impurities such as metals from the above materials include filtration using a filter. The details of the filtration using a filer are described in paragraph [0321] of WO2020/004306A.
Examples of a method for reducing the amount of impurities such as metals included in the above materials include: a method in which raw materials including smaller amounts of metals are used as the raw materials forming the above materials; a method in which the raw materials forming the above materials are filtrated through a filter; and a method in which distillation is performed under the condition that contamination is reduced as much as possible, for example, by coating the inside of the device used with Teflon (registered trademark).
Besides the filtration using a filter, an adsorbent may be used to remove impurities. The filtration using a filter and the absorbent may be used in combination. The adsorbent used may be a well-known adsorbent, and examples of the adsorbent that can be used include inorganic-based adsorbents such as silica gel and zeolite and organic-based adsorbents such as activated carbon. To reduce the amount of impurities such as metals included in the above materials, it is necessary to prevent the metal impurities from mixing in the production process. Whether the metal impurities have been sufficiently removed from the production device can be checked by measuring the content of metal components included in a washing solution used to clean the production device. The content of the metal components included in the washing solution after use is preferably 100 ppt by mass or less, more preferably 10 ppt by mass or less, and still more preferably 1 ppt by mass or less. No particular limitation is imposed on the lower limit of the content, and the content is preferably 0 ppt by mass or more.
An electrically conductive compound may be added to an organic treatment solution such as the rinsing solution in order to prevent failure of chemical solution pipes and various parts (such as filters, O-rings, and tubes) due to electrostatic charges and subsequent electrostatic discharge. No particular limitation is imposed on the electrically conductive compound, and examples thereof include methanol. No particular limitation is imposed on the amount of the electrically conductive compound added. From the viewpoint of maintaining preferred development characteristics or rinsing characteristics, the amount of the electrically conductive compound is preferably 10% by mass or less and more preferably 5% by mass or less. No particular limitation is imposed on the lower limit, and the amount of the electrically conductive compound is preferably 0.01% by mass or more.
The chemical solution pipes used may be, for example, SUS (stainless steel) pipes or pipes coated with antistatic-treated polyethylene, antistatic-treated polypropylene, or an antistatic-treated fluorocarbon resin (such as polytetrafluoroethylene or a perfluoroalkoxy resin). Similarly, antistatic-treated polyethylene, antistatic-treated polypropylene, or an antistatic-treated fluorocarbon resin (such as polytetrafluoroethylene or a perfluoroalkoxy resin) may be used for the filters and the O-rings.
[Method for manufacturing electronic device]
The present invention also relates to a method for manufacturing an electronic device including the pattern forming method described above and to an electronic device manufactured by the manufacturing method.
In preferred modes of the electronic device of the invention, the device is installed in electric and electronic devices (such as household electrical appliances and OA (Office Automation) devices, media-related devices, optical devices, and telecommunication devices).
The present invention also relates to a resin including a repeating unit having a pentafluorosulfanyl group and a repeating unit having an acid-decomposable group. This resin may further include at least one selected from the group consisting of a repeating unit having a lactone group, a repeating unit having a cyclic carbonate group, and a repeating unit having a phenolic hydroxy group.
Examples of the resin include those described in [Resin (A)].
[Method for manufacturing resin]
The present invention also relates to a method for manufacturing a resin including a repeating unit having a pentafluorosulfanyl group and a repeating unit having an acid-decomposable group. The resin is as described above.
The resin manufacturing method of the invention includes the step of adding a solution of the resin to a poor solvent including an organic solvent (Y) to cause the resin to precipitate. The organic solvent (Y) is as described above. The C log P value of the organic solvent (Y) is preferably 1.4 or more.
The present invention will be further described in detail by way of Examples. Materials, amounts used, ratios, treatment details, treatment procedures shown in the following Examples can be appropriately changed so long as they do not depart from the gist of the invention. Therefore, the scope of the present invention should not be construed as limited to the following Examples.
[Components of resist composition]
Resins A-1 to A-71 were used as the resin (A). Resins RA-1 to RA-3 were used as resins in Comparative Examples.
Tables 2 to 4 show the contents (% by mole) of repeating units included in the above resins, their weight average molecular weights (Mw), and their dispersities (Mw/Mn). The content of a repeating unit in a resin is the ratio (molar ratio) of the repeating unit with respect to the total amount of the repeating units included in the resin. Each repeating unit is shown using the structure of its corresponding monomer.
The weight average molecular weight (Mw) and dispersity (Mw/Mn) of each resin were (polystyrene-equivalent values) measured by GPC (carrier: tetrahydrofuran (THF)). The content of each repeating unit was measured by 13C-NMR (nuclear magnetic resonance).
The resins RA-1 to RA-3 are not the resin (A) but are placed in the “Resin (A)” column in Table 8 for convenience.
The structural formulas of the monomers (monomers corresponding to the respective repeating units) shown in Tables 2 to 4 are shown below.
The structures of the photoacid generators used are shown below.
The structures of the acid diffusion control agents used are shown below.
The structural formulas of resins D-1 to D-7 used as the resin (D) are shown below.
Table 5 shows the contents (% by mole) of repeating units included in the above resins, their weight average molecular weights (Mw), and their dispersities (Mw/Mn). The content of a repeating unit in a resin is the ratio (molar ratio) of the repeating unit with respect to the total amount of the repeating units included in the resin. The values of the contents of repeating units shown in Table 5 correspond to the contents of respective structural formulas shown below from left to right.
The weight average molecular weight (Mw) and dispersity (Mw/Mn) of each resin were (polystyrene-equivalent values) measured by GPC (carrier: tetrahydrofuran (THF)). The content of each repeating unit was measured by 13C-NMR (nuclear magnetic resonance).
The solvents used are shown below.
The surfactants used are shown below.
Propylene glycol monomethyl ether acetate (47 g) was heated to 80° C. in a nitrogen flow. While the solution was stirred, a solution mixture of a 50% by mass propylene glycol monomethyl ether acetate solution of a monomer represented by formula M-19 below (42 g), a monomer represented by formula M-80 below (31 g), a monomer represented by formula M-31 below (48 g), cyclohexanone (170 g), and 2,2′-azobisisobutyric acid dimethyl ester [V-601 manufactured by FUJIFILM Wako Pure Chemical Corporation] (10.7 g) was added dropwise over 6 hours to obtain a reaction solution. After completion of the dropwise addition, the reaction solution was further stirred at 80° C. for 2 hours. The resulting reaction solution was allowed to cool, and a large amount of a solvent mixture of heptane and ethyl acetate (heptane:ethyl acetate=9:1, mass ratio) was used to re-precipitate the resin, and the resulting solution was filtered. The solid obtained was vacuum-dried to thereby obtain 83 g of a resin A-1.
The weight average molecular weight (Mw: polystyrene-equivalent value) of the obtained resin A-1 determined by GPC (carrier: tetrahydrofuran (THF)) was 6500, and the dispersity (Mw/Mn) was 1.60. The molar ratio of the repeating units measured by 13C-NMR (nuclear magnetic resonance) was 30/20/50.
The other resins (A) used in the Examples were synthesized and purified using the same procedure as above.
[Preparation of resist compositions]
Components shown in Tables 6 to 8 were mixed such that the concentration of solids was 2.0% by mass. The obtained solution mixtures were filtrated first through polyethylene-made filters having a pore diameter of 50 nm, then through nylon-made filters having a pore diameter of 10 nm, and finally through polyethylene-made filters having a pore diameter of 5 nm to thereby prepare resist compositions (Re-1 to Re-71 and Re-1R to Re-3R).
The solids mean all the components other than the solvent. The resist compositions obtained were used for Examples and Comparative Examples.
In Tables 6 to 8, each “Amount” column shows the content (% by mass) of a component in a resist composition with respect to the total amount of the solids in the resist composition.
A composition AL412 (manufactured by Brewer Science) for formation of an underlayer film was applied to a silicon wafer having a diameter of 12 inches and baked at 205° C. for 60 seconds to form an underlayer film having a film thickness of 20 nm. A resist composition shown in any of Tables 9 to 10 was applied to the underlayer film and baked at 100° C. for 60 seconds to form a resist film having a film thickness of 30 nm.
An EUV exposure device (Micro Exposure Tool manufactured by Exitech, NA 0.3, Quadrupole, outer sigma: 0.68, inner sigma: 0.36) was used to subject the obtained silicon wafer having the resist film to pattern irradiation such that the average line width of the pattern obtained was 18 nm. The reticle used was a mask with a line size of 18 nm and a line:space ratio of 1:1.
The resist film exposed to light was baked at 90° C. for 60 seconds, developed with n-butyl acetate for 30 seconds, and then spin-dried to thereby obtain a negative-type pattern.
[Evaluation item 1]
For each of the patterns obtained by the method described above, the number of defects per silicon wafer was counted using UVision 5 (manufactured by AMAT) and SEMVision G4 (manufactured by AMAT) and evaluated according to the following evaluation criteria. The smaller the number of defects, the better the defect inhibition ability. The results are shown in Tables 9 and 10.
Each of the patterns obtained by the method described above was observed from above using a critical dimension scanning electron microscope (SEM (S-938011 manufactured by Hitachi, Ltd.)). The line width of the pattern was measured at 250 points, and the standard deviation (a) was determined. The measurement variations in line width were evaluated by 36, and the value of 36 was used as the LWR (nm). The smaller the LWR value, the better the LWR performance. The results are shown in Tables 9 to 10.
As can be seen in Tables 9 to 10, when patterns were formed using the resist compositions in the Examples by organic solvent development, the number of defects was small (the defect inhibition ability was good), and the LWR performance was good. However, with the resist compositions in the Comparative Examples, these performance results were worse than those in the Examples.
A composition AL412 (manufactured by Brewer Science) for formation of an underlayer film was applied to a silicon wafer having a diameter of 12 inches and baked at 205° C. for 60 seconds to form an underlayer film having a film thickness of 20 nm. A resist composition shown in any of Tables 11 to 12 was applied to the underlayer film and baked at 100° C. for 60 seconds to form a resist film having a film thickness of 30 nm.
An EUV exposure device (Micro Exposure Tool manufactured by Exitech, NA 0.3, Quadrupole, outer sigma: 0.68, inner sigma: 0.36) was used to subject the obtained silicon wafer having the resist film to pattern irradiation such that the average line width of the pattern obtained was 18 nm. The reticle used was a mask with a line size of 18 nm and a line:space ratio of 1:1.
The resist film exposed to light was baked at 90° C. for 60 seconds, developed with an aqueous tetramethylammonium hydroxide solution (2.38% by mass) for 30 seconds, and rinsed with pure water for 30 seconds. The resulting resist film was spin-dried to thereby obtain a positive-type pattern.
Each of the obtained positive-type patterns was used to evaluate the defect inhibition ability and the LWR performance by the same methods as above.
The results are shown in Tables 11 to 12.
As can be seen in Tables 11 to 12, also when patterns were formed using the resist compositions in the Examples by alkali development, the number of defects was small (the defect inhibition ability was good), and the LWR performance was good. However, with the resist compositions in the Comparative Examples, these performance results were worse than those in the Examples.
The present invention can provide the actinic ray-sensitive or radiation-sensitive resin composition that causes fewer defects and provides good LWR performance. The present invention can also provide the method for manufacturing the actinic ray-sensitive or radiation-sensitive resin composition, provide the actinic ray-sensitive or radiation-sensitive film, the pattern forming method, and the method for manufacturing an electronic device that use the actinic ray-sensitive or radiation-sensitive resin composition, and provide the resin that can be used for the actinic ray-sensitive or radiation-sensitive resin composition.
While the invention has been described in detail with reference to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-121042 | Jul 2021 | JP | national |
This is a continuation of International Application No. PCT/JP2022/027161 filed on Jul. 8, 2022, and claims priority from Japanese Patent Application No. 2021-121042 filed on Jul. 21, 2021, the entire disclosures of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP22/27161 | Jul 2022 | WO |
| Child | 18418023 | US |
