Resist composition and resist pattern formation method

Abstract

The present invention provides a resist composition and a resist pattern formation method, whereby a resist pattern having excellent CDU, sensitivity, and resolution with which it is capable of reproducing a pattern with fine dimensions can be formed. The present invention relates to a resist composition that generates an acid by exposure to light, and that exhibits a change in solubility to a liquid developer through the action of the acid. The resist composition contains a base material component (A1) that exhibits a change in solubility to the liquid developer through the action of the acid, and an acid generating agent component (B) that generates the acid by exposure to light. The acid generating agent component (B) includes a compound represented by general formula (b-1) disclosed in the description.

Description

Resist composition and method for forming a resist pattern

[0001] The present invention relates to a resist composition and a method of forming a resist pattern.

[0002] In lithography, for example, a resist film made of a resist material is formed on a substrate, selectively exposed to light, and then developed to form a resist pattern of a predetermined shape on the resist film. Resist materials that change the exposed portions of the resist film to dissolve in a developer are called positive-type resists, while resist materials that change the exposed portions to insoluble in a developer are called negative-type resists. In recent years, advances in lithography technology have rapidly led to the miniaturization of patterns in the manufacture of semiconductor devices and liquid crystal display devices. A common method for miniaturization is to shorten the wavelength (increase the energy) of the exposure light source. Specifically, while ultraviolet light, typically g-line and i-line, was previously used, mass production of semiconductor devices using KrF excimer lasers and ArF excimer lasers has recently begun. Furthermore, research is also being conducted on light sources with shorter wavelengths (higher energy) than excimer lasers, such as extreme ultraviolet (EUV), electron beams (EB), and X-rays.

[0003] In this situation, resist materials are required to have lithography properties such as sensitivity to these exposure light sources or energy sources, and resolution capable of reproducing patterns with fine dimensions.

[0004] To satisfy these requirements, a chemically amplified resist composition has been used, which contains an acid generator component that generates acid upon exposure and a base component whose solubility in a developer changes due to the action of acid.

[0005] For example, Patent Document 1 discusses a resist composition and a method for forming a resist pattern that are capable of forming a resist pattern with excellent resolution, DOF (Depth of Focus), and pattern shape. Patent Document 1 also describes a resist composition that uses an acid generator component having a specific molar absorption coefficient and employs a polymer compound having a plurality of structural units with a specific structure.

[0006] International Publication No. 2023 / 127692

[0007] As lithography technology continues to advance and resist patterns become increasingly finer, resist compositions are required to have lithography properties such as high sensitivity, resolution capable of reproducing patterns with fine dimensions, and excellent CDU (Critical Dimension Uniformity).

[0008] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a resist composition and a method of forming a resist pattern that are capable of forming a resist pattern that is excellent in sensitivity, resolution, and CDU.

[0009] As a result of intensive research conducted by the inventors in order to solve the above-mentioned problems, they discovered that the following configurations make it possible to obtain a resist composition and a method of forming a resist pattern that are capable of forming a resist pattern that is all excellent in sensitivity, resolution, and CDU, and thus completed the present invention.

[0010] That is, the present invention is as follows: A resist composition according to a first embodiment of the present invention is a resist composition that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid, and contains a base component (A1) whose solubility in a developer changes due to the action of the acid, and an acid generator component (B) that generates an acid upon exposure, wherein the acid generator component (B) includes a compound represented by the following general formula (b-1):

[0011]

[0012] In general formula (b-1), Ra represents an arbitrary organic group. ｍ＋ represents an m-valent organic cation, and m represents an integer of 1 or more.

[0013] A resist composition according to a second embodiment of the present invention comprises a base component (A2) containing an alkali-soluble resin (A2), an acid generator component (B) that generates an acid upon exposure, and a crosslinking agent (C), wherein the alkali-soluble resin (A2) has a structural unit (a10) represented by the following general formula (a10-1), the acid generator component (B) contains a compound represented by the following general formula (b-1), and the crosslinking agent (C) contains at least one crosslinking agent selected from the group consisting of a melamine-based crosslinking agent, a urea-based crosslinking agent, an alkylene urea-based crosslinking agent, a glycoluril-based crosslinking agent, and an epoxy-based crosslinking agent.

[0014]

[0015] In general formula (a10-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ｘ１ is a single bond or a divalent linking group. ｘ１ is (n ａｘ１ +1)-valent aromatic hydrocarbon group. ａｘ１ is an integer of 1 or greater.

[0016]

[0017] In general formula (b-1), Ra represents an arbitrary organic group. ｍ＋ represents an m-valent organic cation, and m represents an integer of 1 or more.

[0018] A method for forming a resist pattern according to a third embodiment of the present invention is a method for forming a resist pattern, including the steps of forming a resist film on a support using the resist composition according to the first or second embodiment of the present invention, exposing the resist film to light, and developing the resist film to form a resist pattern.

[0019] The present invention is capable of providing a resist composition and a method of forming a resist pattern that are capable of forming a resist pattern that is excellent in all aspects of sensitivity, resolution, and CDU.

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes in detail the preferred embodiments of the present invention, but the present invention is not limited to the following preferred embodiments.

[0021] In this disclosure, "aliphatic" is a relative concept to aromatic and is defined as meaning a group, compound, etc. that does not have aromaticity. Unless otherwise specified, "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, "alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups. A "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group have been substituted with halogen atoms, and examples of such halogen atoms include fluorine, chlorine, bromine, and iodine atoms. A "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which some or all of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms. A "structural unit" refers to a monomer unit that constitutes a polymer compound (resin, polymer, copolymer). The phrase "optionally has a substituent" refers to the case in which a hydrogen atom (-H) is replaced with a monovalent group, and the case in which a methylene group (-CH ２ The term "exposure" encompasses both cases where the radical (-) is substituted with a divalent group. The term "exposure" encompasses all cases of irradiation with radiation.

[0022] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly divided into non-polymers and polymers. Non-polymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, the term "low molecular weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, the terms "resin," "high molecular weight compound," or "polymer" refer to a polymer having a molecular weight of 1000 or more. The molecular weight of a polymer is determined by the weight average molecular weight in terms of polystyrene by GPC (gel permeation chromatography).

[0023] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, such as an ethylenic double bond.

[0024] The term "structural unit derived from an acrylic acid ester" refers to a structural unit formed by cleavage of the ethylenic double bond of an acrylic acid ester. ２ ═CH—COOH) with an organic group substituted for the hydrogen atom at the carboxyl end of the acrylate ester. The hydrogen atom bonded to the α-position carbon atom in the acrylate ester may be substituted with a substituent. The substituent (R α０ ) is an atom or group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms. α０ ) is substituted with a substituent containing an ester bond, or α０ This also includes α-hydroxyacrylic esters in which the α-position carbon atom of an acrylic ester is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group. Unless otherwise specified, the α-position carbon atom of an acrylic ester refers to the carbon atom to which the carbonyl group of the acrylic ester is bonded. Hereinafter, an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom is substituted with a substituent may be referred to as an α-substituted acrylic ester. Furthermore, acrylic esters and α-substituted acrylic esters may be collectively referred to as "(α-substituted) acrylic esters."

[0025] The term "structural unit derived from hydroxystyrene" refers to a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene. The term "structural unit derived from a hydroxystyrene derivative" refers to a structural unit formed by cleavage of the ethylenic double bond of a hydroxystyrene derivative. The term "hydroxystyrene derivative" encompasses hydroxystyrenes in which the hydrogen atom at the α-position is substituted with other substituents such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include hydroxystyrenes in which the hydrogen atom at the α-position is optionally substituted with a substituent, but the hydrogen atom of the hydroxyl group is substituted with an organic group; and hydroxystyrenes in which the hydrogen atom at the α-position is optionally substituted with a substituent, but a substituent other than a hydroxyl group is bonded to the benzene ring. Unless otherwise specified, the term "α-position (carbon atom at the α-position)" refers to the carbon atom to which the benzene ring is bonded. Examples of substituents substituting the hydrogen atom at the α-position of hydroxystyrene include the same as those listed as the α-position substituents in the α-substituted acrylic esters.

[0026] The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, and specific examples thereof include alkyl groups having 1 to 5 carbon atoms (methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups). Specific examples of halogenated alkyl groups as the substituent at the α-position include groups in which some or all of the hydrogen atoms of the above-mentioned "alkyl group as the substituent at the α-position" have been substituted with halogen atoms. Examples of such halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine atoms being particularly preferred. Specific examples of hydroxyalkyl groups as the substituent at the α-position include groups in which some or all of the hydrogen atoms of the above-mentioned "alkyl group as the substituent at the α-position" have been substituted with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

[0027] In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. Furthermore, in the present disclosure, when multiple substances corresponding to each component are present in the composition, the amount of each component refers to the total amount of the multiple corresponding substances present in the composition, unless otherwise specified. Furthermore, chemical structural formulas in the present disclosure may be described as simplified structural formulas in which hydrogen atoms are omitted. In the present disclosure, depending on the structure represented by the chemical formula, asymmetric carbons may be present, and enantiomers or diastereoisomers may exist. In such cases, a single chemical formula represents these isomers. These isomers may be used alone or as a mixture. In the present disclosure, "mass %" and "wt %" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0028] [Resist Composition] In the present disclosure, a resist composition that forms a positive resist pattern by dissolving and removing exposed portions of a resist film is referred to as a positive resist composition, and a resist composition that forms a negative resist pattern by dissolving and removing unexposed portions of a resist film is referred to as a negative resist composition. The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Furthermore, the resist composition of this embodiment may be for use in an alkaline development process in which an alkaline developer is used for the development treatment during resist pattern formation, or may be for use in a solvent development process in which a developer containing an organic solvent (organic developer) is used for the development treatment. In other words, the resist composition of this embodiment is a "positive resist composition for an alkaline development process" that forms a positive resist pattern in an alkaline development process, and a "negative resist composition for a solvent development process" that forms a negative resist pattern in a solvent development process.

[0029] A resist composition related to a first embodiment of the present invention is a resist composition that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid. The resist composition includes a base component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes due to the action of an acid, and an acid generator component (B) (hereinafter also referred to as "component (B)") that generates an acid upon exposure, and the acid generator component (B) includes a compound represented by the following general formula (b-1):

[0030] A resist composition related to a second embodiment of the present invention contains a base component (A2) that contains an alkali-soluble resin (A2) (hereinafter also referred to as "component (A2)"), an acid generator component (B) that generates acid upon exposure, and a crosslinker (C) (hereinafter also referred to as "component (C)"), wherein the alkali-soluble resin (A2) has a structural unit (a10) represented by the following general formula (a10-1), the component (B) contains a compound represented by the following general formula (b-1), and the crosslinker (C) contains at least one crosslinker selected from the group consisting of melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, glycoluril-based crosslinking agents, and epoxy-based crosslinking agents.

[0031] When a resist film is formed using the resist composition according to the first embodiment of the present invention and the resist film is subjected to selective exposure, an acid is generated in the exposed areas of the resist film, and the solubility of the component (A1) in a developer changes due to the action of the acid, while the solubility of the component (A1) in a developer does not change in the unexposed areas of the resist film, resulting in a difference in solubility in a developer between the exposed and unexposed areas of the resist film. As a result, when the resist film is developed, the exposed areas of the resist film are dissolved and removed, thereby forming a positive resist pattern.

[0032] When an acid is generated from component (B) upon exposure, the acid reacts with component (C) to form a crosslinking reaction, reducing the solubility of the resist film in a developer. Therefore, when a resist film obtained by coating the resist composition according to the second embodiment on a substrate is selectively exposed to light during resist pattern formation, the solubility of the exposed portions of the resist film in a developer decreases, while the solubility of the unexposed portions of the resist film remains unchanged. This results in a difference in solubility in a developer between the exposed and unexposed portions of the resist film. Therefore, when the resist film is subjected to alkaline or solvent development, the unexposed portions of the resist film are dissolved and removed, forming a negative-tone resist pattern. This allows for the formation of a desired resist pattern with high precision by selective exposure through a desired mask pattern. The resist composition according to the second embodiment of the present invention may be used in an alkaline development process using an alkaline developer for the development treatment during resist pattern formation, or in a solvent development process using a developer containing an organic solvent (organic developer) for the development treatment during resist pattern formation. The resist composition according to the second embodiment of the present invention is particularly useful for alkaline development processes.

[0033] [Resist Composition According to First Embodiment] The component (A1) may generate an acid upon exposure. In this case, the component (A1) is a "base component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid." When the component (A1) is a base component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the component (A1) described below is preferably a polymeric compound that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid. As such a polymeric compound, a copolymer having a structural unit that generates an acid upon exposure can be used. Examples of the structural unit that generates an acid upon exposure include known structural units.

[0034] The resist composition according to the first embodiment of the present invention contains a compound represented by general formula (b-1) described below as an acid generator component (B).

[0035] In the compound represented by general formula (b-1) according to the first embodiment of the present invention, the anion is stabilized due to the electron-withdrawing effect of pentafluorobenzene, resulting in a lower pKa and improved sensitivity. Furthermore, since the compound represented by general formula (b-1) has a bulky structure, it is presumed that the diffusion length of the acid is shortened, thereby enabling the formation of a resist pattern with a good shape.

[0036] <Component (A1)> In the resist composition of the first embodiment of the present invention, as described above, the component (A1) is a base component whose solubility in a developer changes under the action of an acid, and the component (A1) preferably includes a resin component (A1) (hereinafter also referred to as "resin (A1)") whose solubility in a developer changes under the action of an acid. The resin (A1) may be one whose solubility in a developer increases under the action of an acid, or one whose solubility in a developer decreases under the action of an acid. By using the resin (A1), the polarity of the base component (A1) changes before and after exposure, so that good development contrast can be obtained not only in an alkaline development process but also in a solvent development process. As the component (A1), at least the resin (A1) is used, and other polymeric compounds and / or low molecular weight compounds may be used in combination with the resin (A1).

[0037] The resin (A1) preferably contains a structural unit (a10) represented by general formula (a10-1). It may further contain a polymeric compound having a structural unit (a1) containing an acid-decomposable group whose polarity increases when acted upon by acid. In addition to the structural unit (a10), the resin (A1) may also contain a polymeric compound having a structural unit (a1) containing an acid-decomposable group whose polarity increases when acted upon by acid, or may contain a structural unit (st) derived from styrene or a styrene derivative.

[0038] In the resist composition according to the first embodiment of the present invention, the resin (A1) may be used alone, or two or more types may be used in combination.

[0039] <Structural Unit (a10)> The resin (A1) preferably includes a structural unit (a10) represented by general formula (a10-1).

[0040]

[0041] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ｘ１ is a single bond or a divalent linking group. ｘ１ is (n ａｘ１ +1)-valent aromatic hydrocarbon group. ａｘ１ is an integer of 1 or greater.

[0042] In the formula (a10-1), R is the same as R in the formula (a1-1) described below. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferred.

[0043] In the formula (a10-1), Ya ｘ１ is a single bond or a divalent linking group. ｘ１ Examples of the divalent linking group in include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, and a divalent linking group containing a hetero atom.

[0044] Optionally substituted divalent hydrocarbon group: Ya ｘ１ When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0045] ...Ya ｘ１ The aliphatic hydrocarbon group in the above means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0046] ...Straight-chain or branched-chain aliphatic hydrocarbon group The straight-chain aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0047] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, such as a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, or a carbonyl group.

[0048] ...Aliphatic hydrocarbon groups containing a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) that may contain a heteroatom-containing substituent in the ring structure, groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon groups include those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ]decane, tetracyclododecane, and the like.

[0049] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and even more preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. The cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure substituted with a substituent containing a heteroatom. The substituent containing a hetero atom includes —O—, —C(═O)—O—, —S—, and —S(═O) ２ -, -S(=O) ２ —O— is preferred.

[0050] ...Ya ｘ１The aromatic hydrocarbon group in the above formula (1) is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene groups or heteroarylene groups); groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., groups in which one further hydrogen atom has been removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0051] In the aromatic hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0052] Divalent linking group containing a hetero atom: Ya ｘ１ is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, and -S(=O) ２ -, -S(=O) ２ -O-, formula -Y ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ -, -[Y ２１ -C(=O)-O] ｍ” -Y ２２ -, -Y ２１ -OC(=O)-Y ２２ - or -Y ２１ -S(=O) ２ -O-Y ２２ -, wherein Y ２１ and Y ２２ are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 1 to 3.

[0053] When the divalent linking group containing a hetero atom is -C(=O)-NH-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms. ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ -, -[Y ２１ -C(=O)-O] ｍ” -Y ２２ -, -Y ２１ -OC(=O)-Y ２２ - and -Y ２１ -S(=O) ２ -O-Y ２２ -Middle, Y ２１ and Y ２２ are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the above-mentioned Ya ｘ１ Examples of the divalent linking group include the same as those (divalent hydrocarbon groups which may have a substituent) mentioned in the description of the divalent linking group in ｘ１ As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferred, a straight-chain alkylene group is more preferred, a straight-chain alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred.

[0054] Ya ｘ１ Among the above, the divalent linking group in is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group. ｘ１is preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, more preferably a single bond or an ester bond [-C(=O)-O-, -O-C(=O)-], and still more preferably a single bond.

[0055] In the formula (a10-1), Wa ｘ１ is (n ａｘ１ +1) valent aromatic hydrocarbon group. ｘ１ The aromatic hydrocarbon group in ａｘ１ Examples of the aromatic ring include a group in which 4n+1) hydrogen atoms have been removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Wa ｘ１ The aromatic hydrocarbon group in (n) may be an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.). ａｘ１ Also included are groups in which one or more hydrogen atoms have been removed. ｘ１ Examples of the aryl group include benzene, naphthalene, anthracene, and biphenyl (n ａｘ１ A group in which (n +1) hydrogen atoms have been removed is preferred, and a group in which (n +1) hydrogen atoms have been removed from benzene or naphthalene is preferred. ａｘ１ A group in which (n +1) hydrogen atoms have been removed from benzene is more preferred, ａｘ１ A group in which 1) hydrogen atoms have been removed is more preferred.

[0056] Wa ｘ１The aromatic hydrocarbon group in may or may not have a substituent, but preferably has no substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent include Ya ｘ１ Examples of the substituents for the cyclic aliphatic hydrocarbon group in Wa include the same as those listed above. ｘ１ But from the aromatic ring (n ａｘ１ +1) hydrogen atoms from the aromatic ring, ａｘ１ The substituent is a group that replaces a hydrogen atom in the group from which the remaining hydrogen atoms have been removed (+1). The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group.

[0057] In the formula (a10-1), n ａｘ１ is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, still more preferably 1, 2 or 3, and particularly preferably 1 or 2. ａｘ１ is preferably 1.

[0058] Specific examples of the structural unit (a10) represented by the formula (a10-1) are shown below. α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0059]

[0060]

[0061]

[0062]

[0063] The structural unit (a10) contained in the resin (A1) may be one type, or two or more types. When the resin (A1) contains the structural unit (a10), the proportion of the structural unit (a10) in the resin (A1) is preferably 20 to 90 mol%, more preferably 30 to 80 mol%, and even more preferably 40 to 80 mol%, relative to the total (100 mol%) of all structural units constituting the resin (A1). By ensuring that the proportion of the structural unit (a10) is at least the lower limit, sensitivity can be further improved. On the other hand, by ensuring that the proportion is at most the upper limit, it is easier to achieve a balance with other structural units.

[0064] <Structural Unit (a1)> The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases under the action of acid. An "acid-decomposable group" is a group that has acid decomposability, such that at least some of the bonds in the structure of the acid-decomposable group can be cleaved by the action of acid. Examples of acid-decomposable groups whose polarity increases under the action of acid include groups that decompose under the action of acid to generate a polar group. Examples of polar groups include carboxy groups, hydroxyl groups, amino groups, and sulfo groups (-SO ３H). Among these, polar groups containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar groups") are preferred, with carboxyl groups or hydroxyl groups being more preferred, and carboxyl groups being particularly preferred. More specific examples of acid-decomposable groups include groups in which the polar groups are protected with acid-dissociable groups (for example, groups in which the hydrogen atoms of OH-containing polar groups are protected with acid-dissociable groups). Here, the term "acid-dissociable group" refers to both (i) a group having acid dissociability in which the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, and (ii) a group in which a portion of the bond is cleaved by the action of an acid, and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group. The acid-dissociable group constituting the acid-decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid-dissociable group, and thus, when the acid-dissociable group is dissociated by the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, thereby increasing the polarity.As a result, the polarity of the resin (A1) as a whole increases.The increase in polarity relatively changes the solubility in the developer, increasing the solubility when the developer is an alkaline developer, and decreasing the solubility when the developer is an organic developer.

[0065] The structural unit (a1) preferably contains an acid-decomposable group having an alicyclic hydrocarbon group, and more preferably contains an acid-decomposable group having a monocyclic alicyclic hydrocarbon group. When the acid-decomposable group (acid-dissociable group) in the structural unit (a1) contains an alicyclic hydrocarbon group, the structural unit (a1) has an appropriate bulkiness, which allows for appropriate adjustment of acid diffusion control and solubility in a developer, thereby reducing roughness when forming a resist pattern. Examples of the acid-dissociable group in the structural unit (a1) include those that have been proposed as acid-dissociable groups for base resins for chemically amplified resists. Specific examples of acid-dissociable groups that have been proposed as base resins for chemically amplified resist compositions include "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "tertiary alkyloxycarbonyl acid-dissociable groups."

[0066] Acetal-Type Acid-Dissociable Group: Among the polar groups, examples of the acid-dissociable group that protects a carboxy group or a hydroxyl group include acid-dissociable groups represented by the following formula (a1-r-1) (hereinafter, sometimes referred to as "acetal-type acid-dissociable group").

[0067]

[0068] [In the formula, Ra' １ , Ra' ２ is a hydrogen atom or an alkyl group. ３ is a hydrocarbon group, and Ra' ３ is Ra' １ , Ra' ２ may be bonded to any one of the following to form a ring.]

[0069] In formula (a1-r-1), Ra' １ and Ra' ２ Among Ra', at least one is preferably a hydrogen atom, and more preferably both are hydrogen atoms. １ or Ra' ２ When is an alkyl group, examples of the alkyl group include the same alkyl groups as those exemplified as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester above, and alkyl groups having 1 to 5 carbon atoms are preferred. Specific examples include linear or branched alkyl groups. More specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. A methyl group or an ethyl group is more preferred, and a methyl group is particularly preferred.

[0070] In formula (a1-r-1), Ra' ３Examples of the hydrocarbon group include a linear or branched alkyl group, and a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Of these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0071] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0072] Ra' ３ When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As an aliphatic hydrocarbon group that is a monocyclic group, a group in which one hydrogen atom has been removed from a monocycloalkane is preferred. As the monocycloalkane, one having 3 to 6 carbon atoms is preferred, and specific examples thereof include cyclopentane and cyclohexane. As an aliphatic hydrocarbon group that is a polycyclic group, a group in which one hydrogen atom has been removed from a polycycloalkane is preferred, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferred, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0073] Ra' ３When the cyclic hydrocarbon group described above becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Ra' ３ Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (an aryl group or a heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0074] Ra' ３ The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R Ｐ１ , -R Ｐ２ -O-R Ｐ１ , -R Ｐ２ -CO-R Ｐ１ , -R Ｐ２ -CO-OR Ｐ１ , -R Ｐ２ -O-CO-R Ｐ１ , -R Ｐ２ -OH, -R Ｐ２ -CN or -RＰ２ -COOH (hereinafter, these substituents are collectively referred to as "Ra ０５ ") etc. Here, R Ｐ１ is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Ｐ２ is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Ｐ１ and R Ｐ２ Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group, and the aromatic hydrocarbon group may be substituted with fluorine atoms. The cyclic hydrocarbon group may have one or more of one type of the above-mentioned substituents, or may have one or more of each of two or more types of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.0]octanyl group, and the like. ２，６ ]decanyl group, tricyclo[3.3.1.1 ３，７ ] decanyl group, tetracyclo[6.2.1.1 ３，６ .0 ２，７ Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0075] Ra' ３ But Ra' １ , Ra' ２When the cyclic group is bonded to any one of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0076] Tertiary alkyl ester acid-dissociable group: Among the above polar groups, examples of the acid-dissociable group that protects a carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2): Of the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group will hereinafter be referred to as "tertiary alkyl ester acid-dissociable groups" for convenience.

[0077]

[0078] [In the formula, Ra' ４ ~Ra' ６ represents a hydrocarbon group, and Ra' ５ , Ra' ６ may be bonded to each other to form a ring.

[0079] Ra' ４ Examples of the hydrocarbon group represented by Ra' include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. ４ The linear or branched alkyl group and the cyclic hydrocarbon group (a monocyclic aliphatic hydrocarbon group, a polycyclic aliphatic hydrocarbon group, and an aromatic hydrocarbon group) in ３ The linear or branched alkyl group and the cyclic hydrocarbon group in Ra' are the same as those in ４ The chain or cyclic alkenyl group in Ra' is preferably an alkenyl group having 2 to 10 carbon atoms. ５ , Ra' ６ The hydrocarbon group of Ra' ３ The hydrocarbon groups are the same as those listed above.

[0080] Ra' ５ and Ra' ６and (a1-r-2) are bonded to each other to form a ring, the acid-dissociable group represented by the above formula (a1-r-2) is preferably a group represented by the following formula (a1-r2-1), a group represented by the following formula (a1-r2-2), or a group represented by the following formula (a1-r2-3). ４ ~Ra' ６ When the groups are not bonded to each other but are independent hydrocarbon groups, suitable examples of the acid-dissociable group represented by formula (a1-r-2) above include groups represented by formula (a1-r2-4) below.

[0081]

[0082] [In formula (a1-r2-1), Ra ０３１ represents an alkyl group, and Yab ０ represents a carbon atom. ０ is Yab ０ and represents a group which forms an alicyclic hydrocarbon group together with Ya, and some or all of the hydrogen atoms in this alicyclic hydrocarbon group may be substituted. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group which forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra １０１ ~Ra １０３ are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. １０１ ~Ra １０３ Two or more of the above may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ In formula (a1-r2-4), Ra′ is an aromatic hydrocarbon group which may have a substituent. １２ and Ra' １３ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms of this chain saturated hydrocarbon group may be substituted. １４represents a hydrocarbon group which may have a substituent. * represents a bond.]

[0083] In the above formula (a1-r2-1), Ra ０３１ is preferably a chain alkyl group, and is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, part of which may be substituted with a halogen atom or a heteroatom-containing group.

[0084] Ra ０３１ The linear alkyl group in Ra has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. ０３１ In the formula (I), the branched alkyl group is the above-mentioned Ra' ４ The same can be mentioned.

[0085] Ra ０３１ In the above, the alkyl group may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Furthermore, some of the carbon atoms (such as methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -S-, and -S(=O) ２ -, -S(=O) ２ -O- and the like.

[0086] In formula (a1-r2-1), Xab ０ Yab ０ The alicyclic hydrocarbon group formed together with Ra' in the above formula (a1-r-1) is ３Preferred are groups in which one or more hydrogen atoms have been further removed from the groups exemplified as aliphatic hydrocarbon groups (alicyclic hydrocarbon groups), which are monocyclic or polycyclic groups of the above formula. Among these, alicyclic hydrocarbon groups are preferred, monocyclic alicyclic hydrocarbon groups are more preferred, and groups in which two or more hydrogen atoms have been removed from a monocycloalkane are even more preferred. The monocycloalkane is preferably one having 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane, cycloheptane, and cyclooctane.

[0087] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the above formula (a1-r-2). ４ Examples of the cyclic hydrocarbon group include a group in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in the formula (I). The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of the substituent include the above-mentioned Ra' ４ In formula (a1-r2-2), the substituents that the cyclic hydrocarbon group in formula (a1-r2-2) may have are the same as those in formula (a1-r2-2). １０１ ~Ra １０３ In the formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. １０１ ~Ra １０３ In the formula (I), examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. １０１ ~Ra １０３ Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom is particularly preferable.

[0088] The above Ra １０１ ~Ra １０３ Examples of the substituents that the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the formula (I) include the above-mentioned Ra ０５ The same groups as those shown below can be mentioned.

[0089] Ra １０１ ~Ra １０３ Examples of the group containing a carbon-carbon double bond formed by two or more of the above being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidene-ethenyl group, a cyclohexylidene-ethenyl group, etc. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0090] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is the same as Ra' in formula (a1-r-2) above. ４ In formula (a1-r2-3), a group in which one or more hydrogen atoms have been further removed from the group exemplified as the aliphatic hydrocarbon group, which is a monocyclic group or a polycyclic group, is preferred. １０４ Examples of the aromatic hydrocarbon group in the formula (I) include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. １０４ is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0091] Ra in formula (a1-r2-3) １０４ Examples of the substituent that may be possessed by the group include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group), an alkyloxycarbonyl group, and the like.

[0092] In formula (a1-r2-4), Ra' １２ and Ra' １３ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. １２ and Ra' １３ In the formula (I), the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned Ra １０１ ~Ra １０３ The monovalent saturated chain hydrocarbon group having 1 to 10 carbon atoms in the formula (1) may be substituted in part or in whole. １２ and Ra' １３ Among these, Ra' is more preferably an alkyl group having 1 to 5 carbon atoms, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group. １２ and Ra' １３ In the case where the chain saturated hydrocarbon group represented by the formula: ０５ The same groups as those shown below can be mentioned.

[0093] In formula (a1-r2-4), Ra' １４ is a hydrocarbon group which may have a substituent. １４ The hydrocarbon group in the formula (I) includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0094] Ra' １４ The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Of these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0095] Ra' １４The branched alkyl group in the formula (I) preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and an isopropyl group is preferred.

[0096] Ra' １４ When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0097] Ra' １４ As the aromatic hydrocarbon group in １０４ Among them, the aromatic hydrocarbon groups Ra' are the same as those in １４ is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. １４ Examples of the substituent that may be possessed by Ra include １０４ Examples of the substituents include the same as those that may be possessed by the group.

[0098] Ra' in formula (a1-r2-4) １４When Ra' in formula (a1-r2-4) is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. １４ When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be any one of the 1st, 2nd, and 9th positions of the anthryl group.

[0099] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0100]

[0101]

[0102]

[0103] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0104]

[0105]

[0106]

[0107] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0108]

[0109] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0110]

[0111] Tertiary alkyloxycarbonyl acid-dissociable group: Examples of the acid-dissociable group that protects the hydroxyl group of the polar group include an acid-dissociable group represented by the following formula (a1-r-3) (hereinafter, for convenience, may be referred to as a "tertiary alkyloxycarbonyl acid-dissociable group").

[0112]

[0113] [In the formula, Ra' ７ ~Ra' ９ Each represents an alkyl group.

[0114] In formula (a1-r-3), Ra' ７ ~Ra' ９ are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms. The total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 or 4.

[0115] As the acid-dissociable group, among the groups represented by the above general formulae (a1-r2-1) to (a1-r2-4), the group represented by the above general formula (a1-r2-1) or (a1-r2-4) is preferred.

[0116] Specific examples of the structural unit (a1) include structural units represented by general formula (a1-1) shown below.

[0117] (Structural Unit (a1) Represented by General Formula (a1-1)) In the resist composition according to the first embodiment of the present invention, the base component (A1) preferably contains a polymeric compound having a structural unit (a1) represented by the following general formula (a1-1):

[0118]

[0119] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. １ is a divalent hydrocarbon group which may have an ether bond. ａ１ is an integer from 0 to 2. １ represents an acid-dissociable group.

[0120] In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferred.

[0121] In the formula (a1-1), Va １ The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. １ The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specific examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0122] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0123] Examples of the aliphatic hydrocarbon group containing a ring in its structure include alicyclic hydrocarbon groups (groups in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. A preferred monocyclic alicyclic hydrocarbon group is a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0124] Va １The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (an arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (an aryl group) has been substituted with an alkylene group (for example, a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1. In the formula (a1-1), Ra １ represents an acid-dissociable group. Examples of the acid-dissociable group include those described above, and are preferably acid-dissociable groups represented by the above formulae (a1-r2-1) to (a1-r2-4), and more preferably acid-dissociable groups represented by the above formula (a1-r2-1) or (a1-r2-4).

[0125] In the formula (a1-1), n ａ１ is an integer from 0 to 2. ａ１ is preferably 0 or 1, and more preferably 0.

[0126] The formula (a1-1) is preferably the following formula (a1-2):

[0127]

[0128] (In general formula (a1-2), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ３ represents a divalent hydrocarbon group which may have an ether bond. ３ represents an integer of 0 to 2. ０３１ represents an alkyl group, and Yab ０ represents a carbon atom. ０ is Yab ０ represents a group which, together with the group, forms an alicyclic hydrocarbon group, and some or all of the hydrogen atoms of this alicyclic hydrocarbon group may be substituted.

[0129] In general formula (a1-2), R, Va ３ represents R and Va in formula (a1-1). １ and the same respectively.

[0130] In general formula (a1-2), na ３ is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0131] In general formula (a1-2), Ra ０３１ , Xab ０ , Yab ０ is Ra in formula (a1-r2-1) ０３１ , Xab ０ , Yab ０ and the same respectively.

[0132] In general formula (a1-2), Ra ０３１ Among the above, is preferably a chain alkyl group, more preferably a monovalent chain alkyl group having 1 to 3 carbon atoms, and more specifically, a methyl group, an ethyl group, a propyl group, or an isopropyl group.

[0133] Specific examples of the structural unit (a1) are listed below. α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144] The structural unit (a1) that the resin (A1) may have may be one type, or two or more types. The proportion of the structural unit (a1) in the resin (A1), relative to the total (100 mol%) of all structural units constituting the resin (A1), is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, and even more preferably 10 to 35 mol%. By ensuring that the proportion of the structural unit (a1) is at or above the lower limit of the preferred range, lithography properties such as high sensitivity, resolution, and improved roughness are improved. Furthermore, by ensuring that the proportion is at or below the upper limit, a balance with other structural units can be achieved, resulting in various favorable lithography properties.

[0145] <Structural Unit (st)> In addition to the structural unit (a10), the resin (A1) may further include a structural unit (st) derived from styrene or a styrene derivative.

[0146] The structural unit (st) is a structural unit derived from styrene or a styrene derivative. A "structural unit derived from styrene" refers to a structural unit formed by cleavage of the ethylenic double bond of styrene. A "structural unit derived from a styrene derivative" refers to a structural unit formed by cleavage of the ethylenic double bond of a styrene derivative.

[0147] The term "styrene derivative" refers to a compound in which at least some of the hydrogen atoms of styrene have been substituted with a substituent. Examples of styrene derivatives include those in which the hydrogen atom at the α-position of styrene has been substituted with a substituent, those in which one or more hydrogen atoms on the benzene ring of styrene have been substituted with a substituent, and those in which the hydrogen atom at the α-position of styrene and one or more hydrogen atoms on the benzene ring have been substituted with a substituent.

[0148] Examples of the substituent substituting the hydrogen atom at the α-position of styrene include an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being particularly preferred. The substituent substituting the hydrogen atom at the α-position of styrene is preferably an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms or a fluorinated alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group due to its ease of industrial availability.

[0149] Examples of substituents substituting hydrogen atoms on the benzene ring of styrene include alkyl groups, alkoxy groups, halogen atoms, and halogenated alkyl groups. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and even more preferably a methoxy group or an ethoxy group. Examples of halogen atoms as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. Examples of halogenated alkyl groups as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. The substituent substituting hydrogen atoms on the benzene ring of styrene is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0150] The structural unit (st) is preferably a structural unit derived from styrene, or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms, more preferably a structural unit derived from styrene, or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with a methyl group, and even more preferably a structural unit derived from styrene.

[0151] The structural unit (st) contained in the resin (A1) may be of one type, or may be of two or more types. When the resin (A1) contains the structural unit (st), the proportion of the structural unit (st) is preferably 1 to 30 mol %, and more preferably 3 to 30 mol %, relative to the total (100 mol %) of all structural units constituting the resin (A1).

[0152] <Structural Unit (a20)> In addition to the structural unit (a10), the resin (A1) may further include a structural unit (a20). The structural unit (a20) is a structural unit represented by the following general formula (a20-1):

[0153]

[0154] [In the formula, R ｘ２ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ｘ２ is a divalent linking group. ｘ２ is an aliphatic hydrocarbon group.

[0155] In the formula (a20-1), R ｘ２ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ｘ２ is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms; in terms of industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferred, a hydrogen atom or a methyl group is still more preferred, and a hydrogen atom is particularly preferred.

[0156] In the formula (a20-1), Ya ｘ２ In the formula (a20-1), Ya is a divalent linking group. ｘ２ The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, etc. Examples of the divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom include the above-mentioned Ya ｘ１ Examples of the divalent hydrocarbon group and the divalent linking group containing a hetero atom in the above formula are the same as those in the above formula.

[0157] In the formula (a20-1), Ya ｘ２ Among the above, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof is preferable, and an ester bond [-C(=O)-O-, -O-C(=O)-] is more preferable.

[0158] In the formula (a20-1), Ra ｘ２ is an aliphatic hydrocarbon group. ｘ２ Examples of the aliphatic hydrocarbon group include a linear or branched alkyl group, and a cyclic aliphatic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 2 to 5 carbon atoms, and even more preferably 3 to 5 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group.

[0159] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0160] The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group in which one hydrogen atom has been removed from a monocycloalkane is preferred. As the monocycloalkane, one having 3 to 6 carbon atoms is preferred, and specific examples thereof include cyclopentane and cyclohexane.

[0161] The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0162] The cyclic hydrocarbon group may contain a heteroatom, such as a heterocyclic ring. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the heterocyclic ring include aliphatic heterocyclic rings such as tetrahydrofuran, tetrahydropyran, and tetrahydrothiophene. ｘ２ The aliphatic hydrocarbon group in ｘ２In the above formula, a hydrocarbon group in which some or all of the hydrogen atoms of the aliphatic hydrocarbon group have been substituted with a group having a hetero atom is excluded.

[0163] In the formula (a20-1), Ra ｘ２ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, a group in which one hydrogen atom has been removed from a monocycloalkane, or a group in which one hydrogen atom has been removed from a polycycloalkane, more preferably a linear or branched alkyl group having 1 to 5 carbon atoms, a group in which one hydrogen atom has been removed from a monocycloalkane, or an adamantyl group, still more preferably a linear or branched alkyl group having 1 to 5 carbon atoms, or a group in which one hydrogen atom has been removed from a monocycloalkane, and particularly preferably a linear or branched alkyl group having 1 to 5 carbon atoms.

[0164] Specific examples of the structural unit (a20) represented by the formula (a20-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0165]

[0166] Among the above, the structural unit (a20) is preferably a structural unit represented by any one of the general formulae (a20-01-1), (a20-01-3), (a20-01-4), and (a20-02-1), and more preferably a structural unit represented by any one of the general formulae (a20-01-1), (a20-01-4), and (a20-02-1). The structural unit (a20) contained in the resin (A1) in the resist composition related to the first embodiment of the present invention may be of one type, or may be of two or more types. When the resin (A1) contains the structural unit (a20), the proportion of the structural unit (a20) relative to the total (100 mol%) of all structural units constituting the resin (A1) is preferably 2 to 70 mol%, more preferably 3 to 60 mol%, even more preferably 5 to 50 mol%, and particularly preferably 10 to 40 mol%.

[0167] <Other Structural Units> The resin (A1) may contain other structural units in addition to the structural units (a10), (a1), (st), and (a20) described above. Examples of other structural units include lactone-containing cyclic groups, —SO ２ Examples of the structural unit (a2) include a structural unit containing a -containing cyclic group or a carbonate-containing cyclic group, and a structural unit (a3) ​​that contains a polar group-containing aliphatic hydrocarbon group. Many of the structural units that are conventionally known as those used in resin components of resist compositions can be used as the structural unit (a2) and the structural unit (a3).

[0168] The weight-average molecular weight (Mw) of component (A1) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. When the Mw of component (A1) is equal to or less than the preferred upper limit of this range, the component has sufficient solubility in a resist solvent for use as a resist, while when the Mw is equal to or greater than the preferred lower limit of this range, the component exhibits good dry etching resistance and resist pattern cross-sectional shape. The dispersity (Mw / Mn) of component (A1) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.5. Mn denotes the number-average molecular weight.

[0169] [Resist Composition Related to Second Embodiment] A resist composition related to a second embodiment of the present invention contains a base component (A2) that contains an alkali-soluble resin (A2), an acid generator component (B) that generates an acid upon exposure, and a crosslinking agent (C), wherein the alkali-soluble resin (A2) contains a structural unit (a10) represented by the following general formula (a10-1), the component (B) contains a compound represented by the following general formula (b-1), and the crosslinking agent (C) contains at least one crosslinking agent selected from the group consisting of melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, glycoluril-based crosslinking agents, and epoxy-based crosslinking agents.

[0170]

[0171] In general formula (a10-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ｘ１ is a single bond or a divalent linking group. ｘ１ is (n ａｘ１ +1)-valent aromatic hydrocarbon group. ａｘ１ is an integer of 1 or greater.

[0172] In general formula (b-1), Ra represents an arbitrary organic group. ｍ＋ represents an m-valent organic cation, and m represents an integer of 1 or more.

[0173] <Component (A2)> In the resist composition related to the second embodiment of the present invention, as described above, the component (A2) includes an alkali-soluble resin (A2) (hereafter, also referred to as “resin (A2)”), and the alkali-soluble resin (A2) includes a structural unit (a10) represented by the above general formula (a10-1). Examples of the structural unit (a10) include the same structural units as those described above for the structural unit (a10) in the resist composition related to the first embodiment.

[0174] The structural unit (a10) contained in the resin (A2) may be one type, or may be two or more types. When the resin (A2) contains the structural unit (a10), the proportion of the structural unit (a10) relative to the total (100 mol%) of all structural units constituting the resin (A2) is preferably 30 to 100 mol%, more preferably 40 to 100 mol%, and even more preferably 50 to 100 mol%.

[0175] In addition to the structural unit (a10), the resin (A2) may further include at least one selected from the structural unit represented by the above general formula (a20-1) (structural unit (a20)), and the above structural unit (st) derived from styrene or a styrene derivative. Examples of the structural unit (a20) and the structural unit (st) include the same structural units as the structural unit (a20) and structural unit (st) in the resist composition related to the first embodiment.

[0176] The structural unit (st) contained in the resin (A2) may be of one type, or may be of two or more types. When the resin (A2) contains the structural unit (st), the proportion of the structural unit (st) is preferably 1 to 30 mol %, and more preferably 3 to 30 mol %, relative to the total (100 mol %) of all structural units constituting the resin (A2).

[0177] When the resin (A2) in the resist composition according to the second embodiment of the present invention contains the structural unit (a20), the proportion of the structural unit (a20) in the resin (A2) is preferably 2 to 70 mol%, more preferably 3 to 60 mol%, even more preferably 5 to 50 mol%, and particularly preferably 10 to 40 mol%, relative to the total (100 mol%) of all structural units constituting the resin (A2). By ensuring that the proportion of the structural unit (a20) is at least the above-mentioned preferred lower limit, it is possible to further improve the resolution and CDU. On the other hand, by ensuring that the proportion of the structural unit (a20) is at most the above-mentioned preferred upper limit, it is possible to further improve the resolution. The structural unit (a20) contained in the resin (A2) may be one type, or two or more types.

[0178] <Other Structural Units> The resin (A2) may contain other structural units in addition to the structural unit (a10), structural unit (st), and structural unit (a20) described above. Examples of other structural units include the structural unit (a1) containing a protecting group, a lactone-containing cyclic group, —SO ２ Examples of the structural unit (a1), (a2), and (a3) ​​include a structural unit (a1) that contains a -containing cyclic group or a carbonate-containing cyclic group, and a structural unit (a3) ​​that contains a polar group-containing aliphatic hydrocarbon group. Many of the structural units that are conventionally known as those used in resin components of resist compositions can be used as the structural unit (a1), structural unit (a2), and structural unit (a3).

[0179] In the resist composition according to the second embodiment of the present invention, as the component (A2), one type of compound may be used, or two or more types may be used in combination.

[0180] The weight-average molecular weight (Mw) of component (A2) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 20,000, more preferably 1,500 to 10,000, and even more preferably 2,000 to 5,000. When the Mw of component (A2) is equal to or less than the preferred upper limit of this range, the component has sufficient solubility in resist solvents and alkaline developers for use as a resist, while when the Mw is equal to or greater than the preferred lower limit of this range, the component exhibits good dry etching resistance and resist pattern cross-sectional shape. The dispersity (Mw / Mn) of component (A2) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Here, Mn represents the number-average molecular weight.

[0181] <Acid Generator Component (Component (B))> The resist composition related to the first embodiment of the present invention, and the resist composition related to the second embodiment of the present invention (hereinafter, these may be simply referred to as resist compositions) each contain an acid generator component (B) (hereinafter, also referred to as "component (B)") that generates acid upon exposure, and the acid generator component (B) includes an acid generator (B1) (hereinafter, also referred to as "component (B1)") that consists of a compound represented by the following general formula (b-1):

[0182] In general formula (b-1), Ra represents an arbitrary organic group. ｍ＋ represents an m-valent organic cation, and m represents an integer of 1 or more.

[0183] [Anion part (C ６ F ５ -SO ２ -N － -SO ２ -Ra] In formula (b-1), Ra represents an arbitrary organic group. Examples of the organic group in the arbitrary organic group include monovalent hydrocarbon groups which may have a substituent. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0184] Aliphatic hydrocarbon group in Ra The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in their structure.

[0185] ...Straight-chain or branched-chain aliphatic hydrocarbon groups Examples of the straight-chain or branched-chain aliphatic hydrocarbon groups include alkyl groups, alkenyl groups, and alkynyl groups. Examples of the alkyl groups include alkyl groups having 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, and decyl. Examples of the alkenyl groups include alkenyl groups having 2 to 20 carbon atoms (preferably 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms), such as vinyl, allyl, and butenyl. Examples of the alkynyl groups include alkynyl groups having 2 to 20 carbon atoms (preferably 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms), such as ethynyl and propynyl.

[0186] The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group. A fluorine atom is preferred.

[0187] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of the aliphatic hydrocarbon groups containing a ring in their structure include alicyclic hydrocarbon groups, groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of alicyclic hydrocarbon groups include 3- to 8-membered cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; 3- to 8-membered cycloalkenyl groups such as cyclopentenyl and cyclohexenyl; and bridged cyclic hydrocarbon groups having 4 to 20 carbon atoms (preferably 7 to 12 carbon atoms), such as adamantyl and norbornyl.

[0188] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a halogenated alkoxy group, a hydroxyl group, and a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. Examples of the halogenated alkoxy group as the substituent include groups in which some or all of the hydrogen atoms of the alkoxy group are substituted with the halogen atoms. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. The cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting the ring structure substituted with a substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, and -S(=O) ２ -, -S(=O)２ —O— is preferred.

[0189] Aromatic Hydrocarbon Group in Ra The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl groups or heteroaryl groups); groups in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkyl group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 or 2, and particularly preferably 1.

[0190] In the aromatic hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include a halogen atom, an optionally substituted hydrocarbon group, an alkoxy group, a halogenated alkoxy group, and a hydroxyl group. Examples of the hydrocarbon group in the optionally substituted hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group, with an alkyl group having 1 to 5 carbon atoms being preferred. Examples of the substituent in the optionally substituted hydrocarbon group include a halogen atom, with a fluorine atom being preferred. Examples of the halogen atom, alkoxy group, halogenated alkyl group, and halogenated alkoxy group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0191] In this embodiment, among the above, Ra preferably represents an aryl group, alkyl group, or halogenated alkyl group substituted with a halogen atom, a halogenated alkyl group, or a halogenated alkoxy group, and more preferably represents an aryl group substituted with a halogen atom. The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group. Examples of halogenated alkyl groups include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms, and preferred are groups in which all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. Examples of halogenated alkoxy groups include groups in which some or all of the hydrogen atoms of the alkoxy group are substituted with halogen atoms, and preferred are groups in which all of the hydrogen atoms of the alkoxy group are substituted with halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, and preferred are fluorine atoms. Examples of aryl groups include aryl groups having 6 to 20 carbon atoms, and preferred are phenyl and naphthyl groups.

[0192] The anion moiety in the component (B1) is preferably an anion represented by the following formula (an-b-3):

[0193]

[0194] [In formula (an-b-3), R １ ~R ５ R are each independently a hydrogen atom, a halogen atom, an alkoxy group, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, or a hydrocarbon group which may have a substituent. １ ~R ５ Any two or more of these may be bonded to each other to form a ring.]

[0195] In general formula (an-b-3), R １ ~R ５ Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. １ ~R ５ Examples of the hydrocarbon group in the optionally substituted hydrocarbon group represented by Ra include an alkyl group, an alkenyl group, and an alkynyl group. Examples of the alkyl group, alkenyl group, and alkynyl group include those exemplified as the alkyl group, alkenyl group, and alkynyl group in the aliphatic hydrocarbon group represented by Ra, and an alkyl group having 1 to 5 carbon atoms is preferred. Examples of the substituent in the optionally substituted hydrocarbon group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group, and a halogen atom is preferred, and a fluorine atom is more preferred.

[0196] R １ ~R ５ When any two or more of R １ ~R ５ may form an aromatic ring or an aliphatic ring together with the phenyl group to which it is bonded, and the aromatic ring or aliphatic ring is preferably an aromatic ring or an aliphatic ring having 6 to 20 carbon atoms.

[0197] Specific examples of the anion moiety in the component (B1) are listed below: However, the anion moiety in the component (B1) is not limited to these specific examples.

[0198]

[0199] [Cation moiety: M ｍ＋ ] In the general formula (b-1), M ｍ＋ is an m-valent organic cation, and preferably represents an m-valent onium cation. Among these, sulfonium cation and iodonium cation are preferred. m is an integer of 1 or more.

[0200] M ｍ＋ The organic cation in the formula (I) is preferably an onium cation, more preferably a sulfonium cation or an iodonium cation.

[0201] Preferred cation moieties M ｍ＋ Examples of the cation include organic cations represented by any one of the following general formulas (ca-1) to (ca-3).

[0202]

[0203] [In general formulas (ca-1) to (ca-3), R ２０１ ~R ２０７ each independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group, some of the carbon atoms of which may be substituted with heteroatoms; R ２０１ ~R ２０３ , R ２０６ ~R ２０７ may be bonded to each other to form a ring together with the sulfur atom in the formula. ２０８ ~R ２０９ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R ２１０ represents an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ２ -containing cyclic group, and L ２０１ represents —C(═O)— or —C(═O)—O—.]

[0204] R ２０１ ~R ２０７The aryl group in R is an aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２０１ ~R ２０７ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７ The alkenyl group in R is preferably an alkenyl group having 2 to 10 carbon atoms. ２０１ ~R ２０７ and R ２１０ Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and a group represented by the general formula [-Yca0-Rca0] (Yca0 is a single bond or a divalent linking group, and Rca0 is a hydrogen atom or a hydrocarbon group).

[0205] The divalent linking group for Yca0 in the group represented by the general formula [-Yca0-Rca0] is preferably -S-, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a group formed by a combination of an ether bond (-O-) and a linear or branched alkylene group.

[0206] In the general formula [-Yca0-Rca0], examples of the hydrocarbon group for Rca0 include the same hydrocarbon groups as those for Ra above, and are preferably aliphatic hydrocarbon groups, more preferably linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in the structure.

[0207] Examples of the group represented by the general formula [-Yca0-Rca0] include groups represented by the following formulae (car-1) to (car-7).

[0208]

[0209] [In the formula, R' ２０１are each independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

[0210] R' ２０１ The optionally substituted cyclic group represented by is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Examples of aromatic hydrocarbon groups include aryl groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring or an aromatic compound containing two or more aromatic rings, and a phenyl group or a naphthyl group is preferred. Examples of aliphatic hydrocarbon groups include groups in which one hydrogen atom has been removed from a monocycloalkane or polycycloalkane, and a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantyl group, or a norbornyl group is preferred.

[0211] R' ２０１ The optionally substituted chain alkyl group represented by the formula (I) may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group, and a docosyl group.

[0212] R' ２０１The optionally substituted chain alkenyl group represented by may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl, propenyl (allyl), and butenyl groups. Examples of branched alkenyl groups include 1-methylpropenyl and 2-methylpropenyl groups. Of the above, the propenyl group is particularly preferred as the chain alkenyl group.

[0213] R' ２０１ Examples of the optionally substituted cyclic group represented by formula (a1-r2-1) include the same as the acid-dissociable group represented by formula (a1-r2-1) above.

[0214] R' ２０１ Examples of the substituent in the cyclic group, chain-like alkyl group, or chain-like alkenyl group represented by the formula (I) include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. As the alkyl group as a substituent, an alkyl group having 1 to 6 carbon atoms is preferred, and a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group is most preferred. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group is more preferred, and a methoxy group or an ethoxy group is most preferred. As the halogen atom as a substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or the like is mentioned, and a fluorine atom is preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms.

[0215] R ２０１ ~R ２０３ , R ２０６ ~R ２０７may have some of the carbon atoms substituted with hetero atoms, and when they are bonded to each other to form a ring together with the sulfur atom in the formula, they may be substituted with hetero atoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, or with carbonyl groups, -SO-, -SO ２ -, -SO ３ -, -COO-, -CONH- or -N(R Ｎ )-(the R Ｎ is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a tetrahydrothiophene ring, a thiane ring, a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, a thioxane ring, and a thioxanium ring.

[0216] R ２０８ ~R ２０９ R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ２０８ ~R ２０９ When each of these independently represents an alkyl group, they may be bonded to each other to form a ring.

[0217] R ２１０ represents an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ２ -containing cyclic group. ２１０ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２１０ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２１０ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２１０ -SO which may have a substituent２ In the -containing cyclic group, "-SO ２ -containing cyclic group" means a group having a -SO ２ represents a cyclic group containing a ring containing -, specifically, -SO ２ The sulfur atom (S) in - forms a part of the ring skeleton of the cyclic group. ２ The ring containing - is counted as the first ring, and when there is only this ring, it is called a monocyclic group, and when there is further ring structure, it is called a polycyclic group regardless of the structure. ２ The -containing cyclic group may be a monocyclic group or a polycyclic group. ２ The -containing cyclic group is particularly one that does not contain an -O-SO group in its ring skeleton. ２ Cyclic groups containing -, i.e., -O-SO ２ Preferably, the -O-S- in - is a cyclic group containing a sultone ring forming part of the ring skeleton.

[0218] The cation represented by formula (ca-1) is preferably a cation represented by the following formula (ca-b-2):

[0219]

[0220] [In formula (ca-b-2), Rb ０１ ~Rb ０３ Rb each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, and some of the carbon atoms may be substituted with heteroatoms. ０２ and Rb ０３ may be bonded to form a ring together with the sulfur atom in the formula. ０１ represents a single bond or a divalent linking group.

[0221] In formula (ca-b-2), Rb ０１ represents R in general formula (ca-1). ２０１Examples of the aryl group include the same as the optionally substituted aryl group, the optionally substituted alkyl group, or the optionally substituted alkenyl group listed in 1, and some of the carbon atoms may be substituted with heteroatoms. Among these, an unsubstituted aryl group or an aryl group having as a substituent an alkyl group or a group represented by the above general formula [-Yca0-Rca0] (Yca0 is a single bond or a divalent linking group, and Rca0 is a hydrogen atom or a hydrocarbon group) is more preferred.

[0222] In formula (ca-b-2), Rb ０２ ~Rb ０３ represents R in general formula (ca-1). ２０１ Examples of the Rb include the same aryl group, alkyl group, or alkenyl group that may have a substituent as those mentioned above. ０２ and Rb ０３ may have some of their carbon atoms substituted with heteroatoms, and when they are bonded together to form a ring together with the sulfur atom in the formula, they may be substituted with heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, or with carbonyl groups, -SO-, -SO ２ -, -SO ３ -, -COO-, -CONH- or -N(R Ｎ )-(the R Ｎ is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, in which case the ring in the formula containing the sulfur atom in its ring skeleton is a 3- to 10-membered ring, including the sulfur atom. Specific examples of the ring formed include a tetrahydrothiophene ring, a thiane ring, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, and a thioxane ring.

[0223] Lb ０１ represents a single bond or a divalent linking group. ０１The divalent linking group in formula (ca-b-2) is preferably a carbonyl group (-CO-), an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a group consisting of a combination of a carbonyl group (-CO-) and a linear or branched alkylene group. Specific examples of groups consisting of a combination of a carbonyl group (-CO-) and a linear or branched alkylene group include groups represented by the general formula [*-Yca1-Yca2-**] (Yca1 is a linear or branched alkylene group, and Yca2 is a carbonyl group (-CO-). * indicates a bond to the sulfur atom in formula (ca-b-2). ** indicates a bond to Rb in formula (ca-b-2). ０１ ) are examples of bonds with .

[0224] The cation represented by formula (ca-b-2) is preferably a cation represented by the following formula (ca-b-3):

[0225]

[0226] [In general formula (ca-b-3), Rb ０１ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, and some of the carbon atoms may be substituted with heteroatoms. ０１ is a group that forms an aliphatic ring together with the sulfur atom in the formula. ０１ The aliphatic ring formed by Lb may contain an ether bond and may have a substituent. ０１ represents a single bond or a divalent linking group.

[0227] Rb in general formula (ca-b-3) ０１ represents Rb in general formula (ca-b-2). ０１ is the same as:

[0228] Lb in general formula (ca-b-3) ０１ represents Lb in the general formula (ca-b-2). ０１ is the same as:

[0229] Yb in general formula (ca-b-3)０１ is a group that forms an aliphatic ring together with the sulfur atom in the formula. The aliphatic ring may have a substituent, and examples of the substituent include Rb in the general formula (ca-b-2). ０１ The substituents may be the same as those that may be possessed by Yb in general formula (ca-b-3). ０１ is preferably a group which forms a tetrahydrothiophene ring or a thiane ring together with the sulfur atom in the formula.

[0230] Specific examples of the cation moiety of component (B) are shown below, but are not limited to these. For example, specific examples of suitable cations represented by formula (ca-1) include cations represented by any of the following formulas (ca-1-1) to (ca-1-67):

[0231]

[0232]

[0233]

[0234] (In the formula, g1, g2, and g3 represent the number of repeating units, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.)

[0235]

[0236] [In the formula, R” ２０１ is a substituent, and the substituent is the same as R ２０１ ~R ２０７ , and R ２１０ The substituents are the same as those exemplified as the substituents that may be possessed by

[0237] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by any of the following formulas (ca-3-1) to (ca-3-7).

[0238]

[0239] The cationic moiety of the component (B) is preferably as follows:

[0240]

[0241]

[0242] [In the formula, R” ２０１ is a substituent, and the substituent is an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, or a group represented by any of the above general formulae (car-r-1) to (car-r-7).

[0243] As the cation portion of component (B), among the above, a cation represented by any one of chemical formulas (ca-1-1), (ca-1-16), (ca-01-1) to (ca-01-14) is preferred, a cation represented by any one of chemical formulas (ca-01-1) to (ca-01-3), (ca-01-9), (ca-01-11) to (ca-01-13) is more preferred, and a cation represented by any one of chemical formulas (ca-01-1) to (ca-01-3), (ca-01-11) is even more preferred.

[0244] The compound represented by the above general formula (b-1) is preferably a compound represented by the following general formula (b-2).

[0245]

[0246] In general formula (b-2), Ra represents an arbitrary organic group. ０１ ~Rb ０３ Rb each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, and some of the carbon atoms may be substituted with heteroatoms. ０２ and Rb ０３ may be bonded to form a ring together with the sulfur atom in the formula. ０１ represents a single bond or a divalent linking group.

[0247] In general formula (b-2), Ra is the same as Ra in general formula (b-1).

[0248] In general formula (b-2), Rb ０１ ~Rb ０３ and Lb ０１ represents Rb in the above formula (ca-b-2). ０１ ~Rb ０３ and Lb ０１The compound represented by the above general formula (b-2) is preferably a compound represented by the following general formula (b-3):

[0249]

[0250] [In general formula (b-3), R １ ~R ５ R are each independently a hydrogen atom, a halogen atom, an alkoxy group, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, or a hydrocarbon group which may have a substituent. １ ~R ５ Any two or more of Rb may be bonded to each other to form a ring. ０１ ~Rb ０３ Rb each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, and some of the carbon atoms may be substituted with heteroatoms. ０２ and Rb ０３ may be bonded to form a ring together with the sulfur atom in the formula. ０１ represents a single bond or a divalent linking group.

[0251] In general formula (b-3), R １ ~R ５ Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. １ ~R ５ Examples of the hydrocarbon group in the optionally substituted hydrocarbon group represented by Ra include an alkyl group, an alkenyl group, and an alkynyl group. Examples of the alkyl group, alkenyl group, and alkynyl group include those exemplified as the alkyl group, alkenyl group, and alkynyl group in the aliphatic hydrocarbon group represented by Ra, and an alkyl group having 1 to 5 carbon atoms is preferred. Examples of the substituent in the optionally substituted hydrocarbon group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group, and a halogen atom is preferred, and a fluorine atom is more preferred.

[0252] R １ ~R ５When any two or more of R １ ~R ５ may form an aromatic ring or an aliphatic ring together with the phenyl group to which it is bonded, and the aromatic ring or aliphatic ring is preferably an aromatic ring or an aliphatic ring having 6 to 20 carbon atoms.

[0253] In general formula (b-3), Rb ０１ ~Rb ０３ and Lb ０１ represents Rb in the above formula (ca-b-2). ０１ ~Rb ０３ and Lb ０１ is the same as:

[0254] The compound represented by the above general formula (b-3) is preferably a compound represented by the following general formula (b-4).

[0255]

[0256] [In general formula (b-4), R １ ~R ５ R are each independently a hydrogen atom, a halogen atom, an alkoxy group, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, or a hydrocarbon group which may have a substituent. １ ~R ５ Any two or more of Rb may be bonded to each other to form a ring. ０１ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, and some of the carbon atoms may be substituted with heteroatoms. ０１ is a group that forms an aliphatic ring together with the sulfur atom in the formula. ０１ The aliphatic ring formed by Lb may contain an ether bond and may have a substituent. ０１ represents a single bond or a divalent linking group.

[0257] R in general formula (b-4) １ ~R ５ represents R in the general formula (b-3) １ ~R ５ is the same as:

[0258] Rb in general formula (b-4)０１ represents Rb in the above formula (ca-b-2). ０１ is the same as:

[0259] Lb in general formula (b-4) ０１ is Lb in the above formula (ca-b-2) ０１ is the same as:

[0260] Yb in general formula (b-4) ０１ is Yb in (ca-b-3) above ０１ is the same as:

[0261] Specific examples of suitable components (B) are listed below.

[0262]

[0263] The compound represented by formula (b-1) can be produced by a known method.

[0264] In the resist composition of this embodiment, one type of component (B) may be used alone, or two or more types may be used in combination. In the resist composition of this embodiment, the amount of component (B) per 100 parts by mass of component (A1) or component (A2) is preferably 1 to 40 parts by mass, more preferably 1 to 30 parts by mass, and even more preferably 1 to 25 parts by mass. When the amount of component (B) is at least as large as the lower limit of the aforementioned preferred range, a resist pattern that exhibits excellent sensitivity, resolution, and CDU is easily formed. On the other hand, when the amount of component (B) is at most the upper limit of the aforementioned preferred range, a uniform solution is easily obtained when the components of the resist composition are dissolved in an organic solvent, and the storage stability of the resist composition is further improved.

[0265] Regarding Component (B2): The resist composition of this embodiment may contain an acid generator component (hereafter referred to as "component (B2)") other than the component (B) as long as the effects of the present invention are not impaired. There are no particular limitations on the component (B2), and any of the components that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl- or bisarylsulfonyldiazomethanes and poly(bissulfonyl)diazomethanes, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0266] In the resist composition of this embodiment, the component (B2) may be used alone, or two or more types may be used in combination. When the resist composition contains the component (B2), the amount of the component (B2) in the resist composition is preferably 50 parts by mass or less, more preferably 1 to 40 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of the component (A1) or (A2). By ensuring that the amount of the component (B2) is within the above range, sufficient pattern formation is achieved. Furthermore, when the components of the resist composition are dissolved in an organic solvent, a homogeneous solution is easily obtained, which is preferable because the storage stability of the resist composition is improved.

[0267] <Component (C)> The resist composition according to the second embodiment of the present invention contains a crosslinking agent (C) (hereafter referred to as “component (C)”). The component (C) is at least one crosslinking agent selected from the group consisting of melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, glycoluril-based crosslinking agents, and epoxy-based crosslinking agents.

[0268] Examples of melamine-based crosslinking agents include compounds in which melamine and formaldehyde are reacted to replace the hydrogen atoms of the amino groups with hydroxymethyl groups, and compounds in which melamine, formaldehyde, and a lower alcohol are reacted to replace the hydrogen atoms of the amino groups with lower alkoxymethyl groups.Specific examples include hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, and hexabutoxybutylmelamine, with hexamethoxymethylmelamine being preferred.

[0269] Examples of urea-based crosslinking agents include compounds in which urea and formaldehyde are reacted to substitute the hydrogen atoms of amino groups with hydroxymethyl groups, and compounds in which urea, formaldehyde, and a lower alcohol are reacted to substitute the hydrogen atoms of amino groups with lower alkoxymethyl groups.Specific examples include bismethoxymethylurea, bisethoxymethylurea, bispropoxymethylurea, and bisbutoxymethylurea, with bismethoxymethylurea being preferred.

[0270] Examples of the alkylene urea crosslinking agent include compounds represented by the following general formula (CA-1).

[0271]

[0272] [In formula (CA-1), Rc １ and Rc ２ are each independently a hydroxyl group or a lower alkoxy group, and Rc ３ and Rc ４ are each independently a hydrogen atom, a hydroxyl group, or a lower alkoxy group, and vc is an integer of 0 to 2.

[0273] Rc １ and Rc ２ When Rc is a lower alkoxy group, it is preferably an alkoxy group having 1 to 4 carbon atoms, and may be linear or branched. １ and Rc ２ may be the same or different from each other. It is more preferable that they are the same. ３ and Rc ４When Rc is a lower alkoxy group, it is preferably an alkoxy group having 1 to 4 carbon atoms, and may be linear or branched. ３ and Rc ４ may be the same or different from each other. It is more preferable that they are the same. vc is an integer of 0 to 2, and preferably 0 or 1. As the alkylene urea crosslinking agent, a compound in which vc is 0 (ethylene urea crosslinking agent) and / or a compound in which vc is 1 (propylene urea crosslinking agent) are particularly preferred.

[0274] The compound represented by the above general formula (CA-1) can be obtained by subjecting alkylene urea and formalin to a condensation reaction, and then reacting the resulting product with a lower alcohol.

[0275] Specific examples of the alkylene urea-based crosslinking agent include ethylene urea-based crosslinking agents such as mono- and / or dihydroxymethylated ethylene urea, mono- and / or dimethoxymethylated ethylene urea, mono- and / or diethoxymethylated ethylene urea, mono- and / or dipropoxymethylated ethylene urea, and mono- and / or dibutoxymethylated ethylene urea; propylene urea-based crosslinking agents such as mono- and / or dihydroxymethylated propylene urea, mono- and / or dimethoxymethylated propylene urea, mono- and / or diethoxymethylated propylene urea, mono- and / or dipropoxymethylated propylene urea, and mono- and / or dibutoxymethylated propylene urea; 1,3-di(methoxymethyl)-4,5-dihydroxy-2-imidazolidinone, 1,3-di(methoxymethyl)-4,5-dimethoxy-2-imidazolidinone, and the like.

[0276] Examples of glycoluril crosslinking agents include glycoluril derivatives in which the N-position is substituted with one or both of a hydroxyalkyl group and an alkoxyalkyl group having 1 to 4 carbon atoms. Such glycoluril derivatives can be obtained by condensation reaction of glycoluril with formalin and then reacting the resulting product with a lower alcohol. Specific examples of glycoluril crosslinking agents include mono-, di-, tri-, and / or tetrahydroxymethylated glycoluril; mono-, di-, tri-, and / or tetramethoxymethylated glycoluril; mono-, di-, tri-, and / or tetraethoxymethylated glycoluril; mono-, di-, tri-, and / or tetrapropoxymethylated glycoluril; and mono-, di-, tri-, and / or tetrabutoxymethylated glycoluril.

[0277] The epoxy-based crosslinking agent is not particularly limited as long as it has an epoxy group, and any one can be selected and used. Among them, those having two or more epoxy groups are preferred. By having two or more epoxy groups, crosslinking reactivity is improved. The number of epoxy groups is preferably two or more, more preferably two to four, and most preferably two. Suitable epoxy-based crosslinking agents are shown below.

[0278]

[0279] Among these, component (C) is —NCH ２ -OCH ３ A crosslinking agent having a group is preferred, and the crosslinking agent is a compound represented by the following formula (c1-1) or (c1-2), -NCH ２ -OCH ３ More preferred is a crosslinking agent selected from the group consisting of a compound having a melamine skeleton and mono-, di-, tri- and / or tetramethoxymethylated glycoluril, ２ -OCH ３ More preferred is a crosslinking agent selected from the group consisting of a compound having a melamine skeleton and a mono-, di-, tri- and / or tetra-methoxymethylated glycoluril.

[0280]

[0281] [In the formula, nc1 and nc2 each independently represent an integer of 1 to 3.]

[0282] The component (C) may be used alone, or two or more types may be used in combination. In the resist composition according to the second embodiment of the present invention, the amount of the component (C) relative to 100 parts by mass of the component (A2) is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, even more preferably 3 to 30 parts by mass, and most preferably 5 to 25 parts by mass. When the amount of the component (C) is at least as large as the lower limit of this range, crosslinking proceeds sufficiently, further improving resolution performance and lithography properties. In addition, a good resist pattern with minimal swelling can be obtained. When the amount is at most this upper limit, the resist composition exhibits good storage stability and is more likely to suppress deterioration of sensitivity over time.

[0283] <Component (D)> The resist compositions according to the first and second embodiments of the present invention preferably further contain an acid diffusion controller component (hereinafter referred to as "component (D)"). The component (D) acts as a quencher that traps acid generated in the resist composition upon exposure. Examples of the component (D) include a nitrogen-containing organic compound (D1) (hereinafter referred to as "component (D1)") and a photodegradable base (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of component (D1) and decomposes upon exposure to lose its acid diffusion control properties. By using a resist composition containing component (D), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. As the component (D), component (D1) is preferred from the viewpoint of improving the transmittance of the resist film to an exposure light source when forming a thick-film resist pattern.

[0284] Regarding the component (D1), the component (D1) is a base component, a nitrogen-containing organic compound component that acts as an acid diffusion controller in the resist composition. There are no particular limitations on the component (D1) as long as it acts as an acid diffusion controller, and any known component may be used. Among these, aliphatic amines or aromatic amines are preferred, and aliphatic amines are more preferred.

[0285] The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of the aliphatic amine include ammonia NH ３ and cyclic amines, or amines in which at least one hydrogen atom of the above is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines). Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0286] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of aliphatic monocyclic amines include piperidine and piperazine. Specific examples of aliphatic polycyclic amines include those having 6 to 10 carbon atoms, such as 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0287] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, and the like, with triethanolamine triacetate being preferred.

[0288] Furthermore, the component (D1) may be an aromatic amine, such as 4-dimethylaminopyridine, 2,6-di-tert-butylpyridine, pyrrole, indole, pyrazole, imidazole, or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, or N-tert-butoxycarbonylpyrrolidine.

[0289] The component (D1) may be used singly, or in combination of two or more types. When the resist composition contains the component (D1), the amount of the component (D1) within the resist composition is typically within a range from 0.01 to 5 parts by mass, per 100 parts by mass of the component (A1) or (A2). By ensuring that the amount is within this range, the resist pattern shape, stability over time during storage, and other properties are improved.

[0290] Regarding the component (D2): The component (D2) is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion controllability, and does not fall under the category of the component (D1), and any known component may be used. By including the component (D2) that does not fall under the category of the above-mentioned component (D1), the resist composition can further improve the contrast between exposed and unexposed areas of the resist film when forming a resist pattern.

[0291] The component (D2) may be used as an acid generator in addition to or in place of the component (B).

[0292] The component (D2) is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion controllability, and is preferably one or more compounds selected from the group consisting of a compound represented by the following general formula (d2-1) (hereinafter referred to as "component (d2-1)"), a compound represented by the following general formula (d2-2) (hereinafter referred to as "component (d2-2)"), and a compound represented by the following general formula (d2-3) (hereinafter referred to as "component (d2-3)"). However, components (d2-1) to (d2-3) exclude those corresponding to general formula (b-1). Since components (d2-1) to (d2-3) decompose and lose their acid diffusion controllability (basicity) in the exposed areas of the resist film, they do not act as quenchers, but act as quenchers in the unexposed areas of the resist film.

[0293]

[0294] [In the formula, Rd １ ~Rd ４ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula, no fluorine atom is bonded to the carbon atom adjacent to the S atom. １ is a single bond or a divalent linking group; m is an integer of 1 or more; M ｍ＋ are each independently an m-valent organic cation.

[0295] {Component (d2-1)} Anion portion In formula (d2-1), Rd １ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of the R' ２０１ Among these, Rd １is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group, an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be connected via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the following formulas (y-a1-1) to (y-a1-8).

[0296]

[0297] [In the formula, V' １０１ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' １０２ is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0298] In the above formula, V' １０２ The divalent saturated hydrocarbon group in V' is preferably an alkylene group having 1 to 30 carbon atoms. １０２ The alkylene group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0299] Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and another ring structure). More preferred examples of the aliphatic cyclic group include a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include straight-chain alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched-chain alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0300] When the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, and nitrogen atoms. Rd １ As the alkyl group, a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms is preferred, and a fluorinated alkyl group in which all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms (linear perfluoroalkyl group) is particularly preferred.

[0301] Specific examples of preferred anion moieties of component (d2-1) are shown below.

[0302]

[0303] Cation moiety In formula (d2-1), M ｍ＋ is an m-valent organic cation. ｍ＋Suitable examples of the organic cation include the same as the cation represented by any one of the general formulae (ca-1) to (ca-3), more preferably the cation represented by the general formula (ca-1), and even more preferably the cation represented by any one of the general formulae (ca-1-1) to (ca-1-67).

[0304] The component (d2-1) may be used alone or in combination of two or more.

[0305] {Component (d2-2)} Anion portion In formula (d2-2), Rd ２ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ However, Rd ２ In the formula, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not substituted with fluorine). This makes the anion of component (d2-2) an appropriately weak acid anion, improving the quenching ability of component (D). ２ The alkyl group is preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. The aliphatic cyclic group includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ] a group (which may have a substituent) in which one or more hydrogen atoms have been removed from decane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor, or the like. ２ The hydrocarbon group may have a substituent, and the substituent may be Rd １ Examples of the substituents include the same as those that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0306] Specific examples of preferred anion moieties of the component (d2-2) are shown below.

[0307]

[0308] Cation moiety In formula (d2-2), M ｍ＋ is an m-valent organic cation, and M in the formula (d2-1) ｍ＋ The component (d2-2) may be used alone or in combination of two or more.

[0309] {Component (d2-3)} Anion portion In formula (d2-3), Rd ３ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ Among these, a fluorinated alkyl group is preferred, and the Rd １ The same fluorinated alkyl groups as those mentioned above are more preferred.

[0310] In formula (d2-3), Rd ４ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group which may have a substituent is preferable. ４ The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. ４ A part of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, etc. ４ The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0311] Rd ４The alkenyl group in R' ２０１ Examples include the same alkenyl groups as those in the above, and vinyl, propenyl (allyl), 1-methylpropenyl, and 2-methylpropenyl groups are preferred. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0312] Rd ４ The cyclic group in the formula (I) is the same as the R' ２０１ Examples of the cyclic groups include those similar to the cyclic groups in the above, and preferred are alicyclic groups in which one or more hydrogen atoms have been removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, or tetracyclododecane, or aromatic groups such as a phenyl group or a naphthyl group. ４ When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in excellent lithography properties. ４ When is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency, and exhibits favorable sensitivity and lithography properties.

[0313] In formula (d2-3), Yd １ represents a single bond or a divalent linking group. １ The divalent linking group in the formula (a10-1) is not particularly limited, but may be any of the following: ｘ１ Examples of the divalent linking group include the same as those exemplified above.

[0314] Specific examples of preferred anion moieties of the component (d2-3) are shown below.

[0315]

[0316]

[0317] Cation moiety In formula (d2-3), M ｍ＋ is an m-valent organic cation, and M in the formula (d1-1) ｍ＋ The component (d2-3) may be used alone or in combination of two or more.

[0318] The component (D2) may be any one of the above components (d2-1) to (d2-3), or a combination of two or more of them. When the resist composition contains the component (D2), the amount of the component (D2) in the resist composition is preferably 0.5 to 25 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 2.5 to 15 parts by mass, per 100 parts by mass of the component (A1) or (A2). When the amount of the component (D2) is at least as large as the preferred lower limit, particularly favorable lithography properties and resist pattern shape are more likely to be obtained. On the other hand, when the amount is at most as large as the upper limit, good sensitivity can be maintained and excellent throughput can also be achieved.

[0319] Production method of component (D2): The production methods of the components (d2-1) and (d2-2) are not particularly limited, and they can be produced by known methods. The production method of component (d2-3) is also not particularly limited, and it can be produced, for example, by the method described in US 2012-0149916.

[0320] <Optional Components> The resist composition of this embodiment may further contain components (optional components) other than the above-described component (A1) or (A2), component (B), component (C), and component (D). Examples of such optional components include the component (S).

[0321] <Organic Solvent Component (S)> The resist composition of this embodiment can be produced by dissolving the resist materials in an organic solvent component (hereafter referred to as "component (S)"). The component (S) can be any solvent that is capable of dissolving the individual components used to form a homogeneous solution, and any solvent can be appropriately selected from among those known as solvents for conventional chemically amplified resist compositions. In the resist composition of this embodiment, the component (S) can be used either alone or as a mixed solvent of two or more different solvents. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0322] Also preferred as component (S) is a mixed solvent of PGMEA and a polar solvent. The blending ratio (mass ratio) can be determined appropriately taking into account the compatibility of PGMEA with the polar solvent, etc. Another preferred component (S) is a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5. The amount of component (S) used is not particularly limited and is appropriately determined based on the coating film thickness and a concentration that allows application to a substrate, etc. Component (S) is generally used so that the solids concentration of the resist composition is within the range of 0.1 to 20 mass%, preferably 0.2 to 15 mass%.

[0323] The resist composition of this embodiment may further contain, as desired, compatible additives such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, and dyes.

[0324] The resist composition according to the first embodiment of the present invention contains the aforementioned component (A1) and component (B), and, if necessary, the optional components described above. Suitable examples of the resist composition include a resist composition containing the component (A1), component (B), and component (D). Furthermore, suitable examples of the resist composition include a resist composition containing the component (A1), component (B), component (D), and component (S).

[0325] The resist composition according to the second embodiment of the present invention contains the above-mentioned component (A2), component (B), and component (C), and, if necessary, the above-mentioned optional components. Suitable examples of the resist composition include a resist composition containing the component (A2), component (B), component (C), and component (D). Furthermore, suitable examples of the resist composition include a resist composition containing the component (A2), component (B), component (C), component (D), and component (S).

[0326] As described above, the resist composition of this embodiment contains an acid generator component (B) that includes the compound represented by the general formula (b-1). The compound represented by the general formula (b-1) has anions that are stabilized by the electron-withdrawing effect of pentafluorobenzene, thereby increasing the acid strength (decreasing the pKa) and achieving high sensitivity.

[0327] (Method of Forming a Resist Pattern) A method of forming a resist pattern according to another embodiment of the present invention includes the steps of forming a resist film on a support using the resist composition of the above-described embodiment, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. One embodiment of such a method of forming a resist pattern can be exemplified by a method of forming a resist pattern as follows.

[0328] First, the resist composition of the above-described embodiment is applied to a support using a spinner or the like, and baked (post-applied bake (PAB)) for 40 to 120 seconds, preferably 50 to 90 seconds, at a temperature of 80 to 150°C to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an EUV exposure device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with electron beams without a mask pattern. Thereafter, the resist film is baked (post-exposure bake (PEB)) for 40 to 120 seconds, preferably 50 to 90 seconds, at a temperature of 80 to 150°C. Next, the resist film is developed. In the case of an alkali development process, the development is performed using an alkaline developer, and in the case of a solvent development process, a developer containing an organic solvent (organic developer). After the development, a rinse treatment is preferably performed. In the case of an alkaline development process, the rinse treatment is preferably a water rinse using pure water, and in the case of a solvent development process, a rinse solution containing an organic solvent is preferably used. In the case of a solvent development process, after the development treatment or rinse treatment, a treatment may be performed to remove the developer or rinse solution adhering to the pattern using a supercritical fluid. After the development treatment or rinse treatment, drying is performed. In addition, in some cases, a bake treatment (post-bake) may be performed after the development treatment. In this way, a resist pattern can be formed.

[0329] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, examples include silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold.

[0330] The wavelength used for exposure is not particularly limited, and radiation such as an ArF excimer laser, a KrF excimer laser, an F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, soft X-rays, etc. The resist composition is highly useful for use with a KrF excimer laser, an ArF excimer laser, EB, or EUV.

[0331] The exposure method for the resist film may be a normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be liquid immersion exposure (liquid immersion lithography), but liquid immersion exposure is preferred. Liquid immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure apparatus is filled in advance with a solvent (immersion medium) having a refractive index higher than that of air, and exposure (immersion exposure) is performed in this state. The liquid immersion medium is preferably a solvent having a refractive index higher than that of air but lower than that of the resist film to be exposed. The refractive index of such a solvent is not particularly limited as long as it is within the above-mentioned range. Examples of solvents having a refractive index higher than that of air but lower than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Water is preferably used as the liquid immersion medium.

[0332] An example of an alkaline developer used in the development treatment in the alkaline development process is a 0.1 to 10% by mass aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent that can dissolve component (A1) or component (A2) (component (A1) or (A2) before exposure), and can be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0333] Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0334] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0335] The organic developer may contain known additives as needed. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants.

[0336] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), or a method of continuously discharging the developer while scanning a developer discharging nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0337] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), or a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0338] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously discharging the rinse liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dipping method), or a method of spraying the rinse liquid onto the surface of the support (spray method).

[0339] The resist composition of the above-described embodiment and the various materials used in the pattern formation method of the above-described embodiment (e.g., resist solvent, developer, rinse, anti-reflective coating composition, top coat composition, etc.) preferably do not contain impurities such as metals, halogen-containing metal salts, acids, alkalis, or components containing sulfur or phosphorus atoms. Examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free of impurities (below the detection limit of the measuring device).

[0340] The method of forming a resist pattern according to the present embodiment, as explained above, uses the resist composition according to the first or second embodiment of the present invention, and therefore when forming a resist pattern, high sensitivity can be achieved, and a resist pattern with excellent lithography properties and a good shape can be formed.

[0341] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0342] <Synthesis Examples of Polymer Compounds (A)-1 to (A)-6> Each polymer compound was synthesized using monomers that derive the structural units constituting the polymer compounds (A)-1 to (A)-6 shown below in a predetermined molar ratio. １３ The copolymerization composition ratio of the polymer compound (the proportion (molar ratio) of each structural unit in the polymer compound) determined by C-NMR, and the weight average molecular weight (Mw) and polydispersity index (PDI) (Mw / Mn) calculated in terms of standard polystyrene determined by GPC measurement are also shown.

[0343]

[0344] <Synthesis Example of Compound (B)-1>

[0345]

[0346] Under a nitrogen atmosphere, precursor (Bpre1) (15.00 g, 30.0 mmol) and salt-exchange compound A (8.98 g, 30.0 mmol) were dissolved in dichloromethane (100 g) in a 300 mL recovery flask, and ultrapure water (50 g) was added. The mixture was allowed to react at room temperature for 30 minutes. After the reaction was completed, the aqueous phase was removed, and the organic phase was washed four times with ultrapure water (50 g). The organic phase was concentrated to dryness using a rotary evaporator to obtain compound (B)-1 (20.3 g, yield = 91.2%).

[0347] <Synthesis of Compounds (B)-2 to (B)-7> Compounds (B)-2 to (B)-7 were obtained in the same manner as in the above "Synthesis Example of Compound (B)-1" except for changing the precursor compound and the salt exchange compound. NMR measurements were performed on each of the obtained compounds, and their structures were identified from the following analytical results.

[0348]

[0349] Table 1 shows the results of NMR measurement of compounds (B)-1 to (B)-6.

[0350]

[0351] [Evaluation of Negative Resist Compositions 1] <Preparation of Negative Resist Composition 1> (Examples 1-1 to 1-16, Comparative Examples 1-1 to 1-4) The components shown in Tables 2 and 3 were mixed and dissolved in a solvent (S-1: a mixed solvent of 225 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) and S-2: 225 parts by mass of propylene glycol monomethyl ether (PGME)) to prepare the resist composition of each example.

[0352]

[0353]

[0354] In Tables 2 and 3, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0355] (A)-1 to (A)-6: the polymer compounds (A)-1 to (A)-6 described above; (B)-1 to (B)-6: acid generators each composed of the compounds (B)-1 to (B)-6 described above;

[0356] (B)-11 to (B)-12: Acid generators consisting of the following comparative compounds (B)-11 to (B)-12, respectively.

[0357]

[0358] (C)-1: A crosslinking agent comprising a compound represented by the following chemical formula (C)-1. (D)-1: An acid diffusion controller comprising a compound represented by the following chemical formula (D)-1.

[0359]

[0360] <Formation of Negative Resist Pattern 1> Each resist composition of each example was applied using a spinner onto an 8-inch silicon wafer that had been treated with hexamethyldisilazane (HMDS) at 110°C for 60 seconds. A pre-baking (PAB) treatment was then performed on a hot plate at 90°C for 60 seconds, followed by drying to form a negative resist film with a thickness of 2 μm. Next, the resist film was selectively irradiated with a KrF excimer laser (248 nm) through a mask pattern (binary mask) using a KrF exposure system NSR-S203B (manufactured by Nikon Corporation; NA (numerical aperture) = 0.60, σ = 0.68). This was followed by a post-exposure bake (PEB) treatment at 110°C for 60 seconds. Next, alkaline development was carried out at 23°C for 60 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developer. Thereafter, the resist was rinsed with pure water for 30 seconds and then spun off and dried. Thereafter, post-baking was carried out at 100°C for 60 seconds. As a result, an isolated space pattern with a width of 500 nm was formed.

[0361] [Sensitivity Evaluation 1] [Evaluation of Optimum Exposure Dose (Eop)] In the above <Formation of Negative Resist Pattern 1>, the optimum exposure dose Eop (mJ / cm) at which an isolated space pattern with a width of 500 nm is formed is ２ This was referred to as "sensitivity (mJ / cm ２ ) are shown in Table 4.

[0362] [Resolution Evaluation 1] In the above <Formation of Negative Resist Pattern 1>, the optimum exposure dose Eop (mJ / cm) at which an isolated space pattern with a width of 500 nm is formed is ２ The exposure dose was then gradually reduced from the optimum exposure dose to form the isolated space pattern, and the space width (nm) of the resolved pattern was measured using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation). This is shown in Table 4 as "resolution (nm)."

[0363] [Evaluation 1 of In-Plane Uniformity (CDU)] The optimum exposure dose Eop (mJ / cm) obtained by the above resolution evaluation 1２ ), the entire wafer was exposed to light, and the CD (space width) of the formed pattern was measured using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation). Then, three times the standard deviation (σ) (3σ) calculated from the measurement results was determined. The results are shown in Table 4 as "CDU (nm)." The smaller the 3σ value determined in this way, the higher the dimensional (CD) uniformity of the multiple spaces formed in the resist film.

[0364]

[0365] As shown in Table 4, it was confirmed that the resist compositions of the examples were superior in sensitivity, resolution, and CDU to the resist compositions of the comparative examples.

[0366] [Evaluation of Negative Resist Compositions 2] <Preparation of Negative Resist Composition 2> (Examples 2-1 to 2-6, Comparative Examples 2-1 to 2-2) The components shown in Table 5 were mixed and dissolved in a solvent (S-1: a mixed solvent of 550 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) and S-2: 550 parts by mass of propylene glycol monomethyl ether (PGME)) to prepare the resist composition of each example.

[0367]

[0368] In Table 5, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0369] (A)-3: the polymer compound (A)-3 described above (B)-1 to (B)-6: acid generators comprising each of the compounds (B)-1 to (B)-6 described above (B)-11 to (B)-12: acid generators comprising each of the comparative compounds (B)-11 to (B)-12 described above (C)-1: a crosslinking agent comprising the compound represented by the chemical formula (C)-1 described above (D)-1: an acid diffusion controller comprising the compound represented by the chemical formula (D)-1 described above

[0370] <Formation of Negative Resist Pattern 2> An organic antireflective coating composition "DUV-42P" (trade name, manufactured by Nissan Chemical Industries, Ltd.) was applied to an 8-inch silicon wafer using a spinner, and then baked on a hot plate at 180°C for 60 seconds to dry, thereby forming an organic antireflective coating with a thickness of 65 nm. Each resist composition of each example was applied to the organic antireflective coating using a spinner, and then dried by pre-baking (PAB) on a hot plate at 100°C for 60 seconds to form a resist film with a thickness of 500 nm. Next, the resist film was selectively irradiated with a KrF excimer laser (248 nm) through a mask pattern using a KrF exposure system NSR-S203 (manufactured by Nikon Corporation; NA (numerical aperture) = 0.68, 2 / 3 Annular). Then, PEB treatment was performed at 120°C for 60 seconds, and further alkaline development was performed at 23°C for 60 seconds using a 2.38% by mass TMAH aqueous solution NMD-3 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, a water rinse was performed using pure water for 30 seconds, and the resist was shaken off and dried. Thereafter, post-baking was performed at 100°C for 60 seconds. As a result, an isolated space pattern with a width of 160 nm was formed.

[0371] [Sensitivity Evaluation 2] [Evaluation of Optimum Exposure Dose (Eop)] In the above <Formation of Negative Resist Pattern 2>, the optimum exposure dose Eop (mJ / cm) at which an isolated space pattern with a width of 160 nm is formed is ２ This was referred to as "sensitivity (mJ / cm ２ ) are shown in Table 6.

[0372] [Resolution Evaluation 2] In the above <Formation of Negative Resist Pattern 2>, the optimum exposure dose Eop (mJ / cm) at which an isolated space pattern with a width of 160 nm is formed is ２ The exposure dose was then gradually reduced from the optimum exposure dose to form the isolated space pattern, and the space width (nm) of the resolved pattern was measured using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation). This is shown in Table 6 as "resolution (nm)."

[0373] [Evaluation 2 of In-Plane Uniformity (CDU)] The optimum exposure dose Eop (mJ / cm) obtained by the above resolution evaluation 2 ２ ), the entire wafer was exposed to light, and the CD (space width) of the formed pattern was measured using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation). Then, three times the standard deviation (σ) (3σ) calculated from the measurement results was determined. The results are shown in Table 6 as "CDU (nm)." The smaller the 3σ value determined in this way, the higher the dimensional (CD) uniformity of the multiple spaces formed in the resist film.

[0374]

[0375] As shown in Table 6, it was confirmed that the resist compositions of the examples were superior in sensitivity, resolution, and CDU to the resist compositions of the comparative examples.

[0376] <Synthesis Example of Polymer Compounds (A)-11 to (A)-13> Each polymer compound was synthesized using monomers that derive the structural units constituting the polymer compounds (A)-11 to (A)-13 shown below, in a predetermined molar ratio. １３ The copolymerization composition ratio of the polymer compound (the proportion (molar ratio) of each structural unit in the polymer compound) determined by C-NMR, and the weight average molecular weight (Mw) and polydispersity index (PDI) (Mw / Mn) calculated in terms of standard polystyrene determined by GPC measurement are also shown.

[0377]

[0378] [Evaluation of Positive Resist Composition 1] <Preparation of Positive Resist Composition 1> (Examples 3-1 to 3-8, Comparative Examples 3-1 to 3-2) The components shown in Table 7 were mixed and dissolved in a solvent (S-1: a mixed solvent of 67 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) and S-2: 67 parts by mass of propylene glycol monomethyl ether (PGME)) to prepare the resist composition of each example.

[0379]

[0380] In Table 7, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0381] (A)-11 to (A)-13: the polymer compounds (A)-11 to (A)-13 described above; (B)-1 to (B)-6: acid generators comprising the compounds (B)-1 to (B)-6 described above; (B)-11 to (B)-12: acid generators comprising the comparative compounds (B)-11 to (B)-12 described above; (D)-1: an acid diffusion controller comprising the compound represented by the chemical formula (D)-1 described above.

[0382] <Formation of Positive Resist Pattern 1> Each resist composition of each example was applied using a spinner onto an 8-inch silicon wafer that had been treated with hexamethyldisilazane (HMDS) at 110°C for 60 seconds. A pre-baking (PAB) treatment was performed on a hot plate at 150°C for 90 seconds, followed by drying to form a positive resist film with a thickness of 10 μm. Next, the resist film was selectively irradiated with a KrF excimer laser (248 nm) through a mask pattern (binary mask) using a KrF exposure system NSR-S203B (manufactured by Nikon Corporation; NA (numerical aperture) = 0.60, σ = 0.68). This was followed by a post-exposure bake (PEB) treatment at 110°C for 90 seconds. Next, alkaline development was carried out at 23°C for 60 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developer. Thereafter, the resist was rinsed with pure water for 30 seconds and then spun off and dried. Thereafter, post-baking was carried out at 100°C for 60 seconds. As a result, an isolated space pattern having a width of 3 µm was formed.

[0383] [Sensitivity Evaluation 3] [Evaluation of Optimum Exposure Dose (Eop)] In the above <Formation of Positive Resist Pattern 1>, the optimum exposure dose Eop (mJ / cm) at which an isolated space pattern with a width of 3 μm is formed is ２ This was referred to as "sensitivity (mJ / cm ２ ) are shown in Table 8.

[0384] [Resolution Evaluation 3] In the above <Formation of Positive Resist Pattern 1>, the optimum exposure dose Eop (mJ / cm) at which an isolated space pattern with a width of 3 μm is formed is ２ The exposure dose was then gradually reduced from the optimum exposure dose to form the isolated space pattern, and the space width (μm) of the resolved pattern was measured using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation). This is shown in Table 8 as "resolution (μm)."

[0385] [Evaluation 3 of In-Plane Uniformity (CDU)] The optimum exposure dose Eop (mJ / cm) obtained by the above-mentioned resolution evaluation 3 ２ ), the entire wafer was exposed to light, and the CD (space width) of the formed pattern was measured using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation). Then, triple the standard deviation (σ) (3σ) calculated from the measurement results was determined. The results are shown in Table 8 as "CDU (nm)." The smaller the 3σ value determined in this way, the higher the dimensional (CD) uniformity of the multiple spaces formed in the resist film.

[0386]

[0387] From the results shown in Table 8, it was confirmed that the resist compositions of the examples were superior in all aspects of sensitivity, resolution, and CDU compared to the resist compositions of the comparative examples.

[0388] [Evaluation of Positive Resist Compositions 2] <Preparation of Positive Resist Composition 2> (Examples 4-1 to 4-6, Comparative Examples 4-1 to 4-2) The components shown in Table 9 were mixed and dissolved in a solvent (S-1: a mixed solvent of 600 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) and S-2: 600 parts by mass of propylene glycol monomethyl ether (PGME)), to prepare the resist composition of each example.

[0389]

[0390] In Table 9, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0391] (A)-11: the polymer compound (A)-11 (B)-1 to (B)-6: acid generators comprising each of the compounds (B)-1 to (B)-6 (B)-11 to (B)-12: acid generators comprising each of the comparative compounds (B)-11 to (B)-12 (D)-1: an acid diffusion controller comprising a compound represented by the chemical formula (D)-1.

[0392] <Formation of Positive Resist Pattern 2> An organic antireflective coating composition "DUV-42P" (manufactured by Nissan Chemical Industries, Ltd.) was applied to a 6-inch silicon wafer using a spinner, and then baked on a hot plate at 180°C for 60 seconds to dry, thereby forming an organic antireflective coating with a thickness of 65 nm. Each resist composition was applied to the antireflective coating using a spinner, and then prebaked (PAB) on a hot plate at 110°C for 60 seconds, followed by drying to form a resist film with a thickness of 500 nm. Using a KrF exposure system NSR-S203B [manufactured by Nikon Corporation; NA (numerical aperture) = 0.68, Sigma = 0.75], the wafer was selectively irradiated with a KrF excimer laser (248 nm) through a photomask (binary mask). This was then subjected to PEB treatment at 110°C for 60 seconds. Next, alkaline development was performed for 60 seconds using a 2.38% by mass TMAH aqueous solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C. Thereafter, a water rinse was performed for 30 seconds using pure water, and the resist was shaken off and dried. Thereafter, post-baking was performed for 60 seconds at 100°C. As a result, in each example, a 1:1 line-and-space (LS) pattern with a line width of 170 nm and a pitch of 340 nm was formed.

[0393] [Sensitivity Evaluation 4] [Evaluation of Optimum Exposure Dose (Eop)] In the above <Formation of Positive Resist Pattern 2>, the optimum exposure dose Eop (mJ / cm) for forming an LS pattern with a line width of 170 nm and a pitch of 340 nm was ２ This was referred to as "sensitivity (mJ / cm ２ ) are shown in Table 10.

[0394] [Resolution Evaluation 4] The line size in the above <Formation of Positive Resist Pattern 2> was observed, and the optimum exposure dose Eop (mJ / cm) for forming an LS pattern with a line width of 170 nm and a pitch of 340 nm was determined. ２ The exposure dose was then gradually reduced from the optimum exposure dose to form the LS pattern, and the space width (nm) of the resolved pattern was measured using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation). This is shown in Table 10 as "resolution (nm)."

[0395] [Evaluation 4 of In-Plane Uniformity (CDU)] The optimum exposure dose Eop (mJ / cm) obtained by the above resolution evaluation 4 ２ ), the entire wafer was exposed to light, and the CD (space width) of the formed pattern was measured using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation). Then, triple the standard deviation (σ) (3σ) calculated from the measurement results was determined. The results are shown in Table 10 as "CDU (nm)." The smaller the 3σ value determined in this way, the higher the uniformity of the dimensions (CD) of the multiple spaces formed in the resist film.

[0396]

[0397] From the results shown in Table 10, it was confirmed that the resist compositions of the examples were superior in sensitivity, resolution, and CDU to the resist compositions of the comparative examples.

[0398] According to the present invention, it is possible to provide a resist composition and a method of forming a resist pattern that are capable of forming a resist pattern that is excellent in sensitivity, resolution, and CDU.

[0399] Although the present invention has been described in detail and with reference to 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 present invention. This application is based on a Japanese patent application (Patent Application No. 2024-057451) filed on March 29, 2024, the contents of which are incorporated herein by reference.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition comprising: a base component (A1) whose solubility in a developer changes due to the action of the acid; and an acid generator component (B) that generates an acid upon exposure, wherein the acid generator component (B) comprises a compound represented by the following general formula (b-1): In general formula (b-1), Ra represents an arbitrary organic group. ｍ＋ represents an m-valent organic cation.

2. A resist composition comprising a base component (A2) containing an alkali-soluble resin (A2), an acid generator component (B) that generates an acid upon exposure, and a crosslinking agent (C), wherein the alkali-soluble resin (A2) has a structural unit (a10) represented by the following general formula (a10-1), the acid generator component (B) contains a compound represented by the following general formula (b-1), and the crosslinking agent (C) contains at least one crosslinking agent selected from the group consisting of a melamine-based crosslinking agent, a urea-based crosslinking agent, an alkylene urea-based crosslinking agent, a glycoluril-based crosslinking agent, and an epoxy-based crosslinking agent. In general formula (a10-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ｘ１ is a single bond or a divalent linking group. ｘ１ is (n ａｘ１ +1)-valent aromatic hydrocarbon group. ａｘ１ is an integer of 1 or greater. In general formula (b-1), Ra represents an arbitrary organic group. ｍ＋ represents an m-valent organic cation.

3. The resist composition according to claim 1 or 2, wherein the compound represented by the general formula (b-1) is a compound represented by the following general formula (b-2): In general formula (b-2), Ra represents an arbitrary organic group. ０１ ~Rb ０３ Rb each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, and some of the carbon atoms may be substituted with heteroatoms. ０２ and Rb ０３ may be bonded to form a ring together with the sulfur atom in the formula. ０１ represents a single bond or a divalent linking group.

4. The resist composition according to claim 3, wherein the compound represented by general formula (b-2) is a compound represented by the following general formula (b-3): [In general formula (b-3), R １ ~R ５ R are each independently a hydrogen atom, a halogen atom, an alkoxy group, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, or a hydrocarbon group which may have a substituent. １ ~R ５ Any two or more of Rb may be bonded to each other to form a ring. ０１ ~Rb ０３ Rb each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, and some of the carbon atoms may be substituted with heteroatoms. ０２ and Rb ０３ may be bonded to form a ring together with the sulfur atom in the formula. ０１ represents a single bond or a divalent linking group.

5. The resist composition according to claim 4, wherein the compound represented by general formula (b-3) is a compound represented by the following general formula (b-4): [In general formula (b-4), R １ ~R ５ R are each independently a hydrogen atom, a halogen atom, an alkoxy group, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, or a hydrocarbon group which may have a substituent. １ ~R ５ Any two or more of Rb may be bonded to each other to form a ring. ０１ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, and some of the carbon atoms may be substituted with heteroatoms. ０１ is a group that forms an aliphatic ring together with the sulfur atom in the formula. ０１ The aliphatic ring formed by Lb may contain an ether bond and may have a substituent. ０１ represents a single bond or a divalent linking group.

6. A method for forming a resist pattern, comprising the steps of forming a resist film on a support using the resist composition according to claim 1 or 2, exposing the resist film to light, and developing the resist film to form a resist pattern.

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