Resist composition, method for forming resist pattern, compound, and acid generator

Abstract

To provide a compound, an acid generator, a resist composition, and a method for forming a resist pattern, capable of forming a resist pattern that simultaneously achieves resolution enabling reproduction of a fine-dimension pattern, a good resist pattern shape, and an excellent DOF margin.SOLUTION: A resist composition generates an acid upon exposure and exhibits a change in solubility in a developing solution by the action of the acid, the resist composition comprising a base material component (A1) that exhibits a change in solubility in the developing solution by 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 general formula (b-1) described in the specification.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resist composition, a method of forming a resist pattern, a compound, and an acid generator. [Background technology]

[0002] In lithography, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed to light, and a development process is performed to form a resist pattern of a predetermined shape in the resist film. A resist material that changes the exposed portion of the resist film so that it dissolves in a developer is called a positive-type resist, and a resist material that changes the exposed portion so that it does not dissolve in a developer is called a negative-type resist. In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, advances in lithography technology have led to rapid progress in miniaturization of patterns. A common method of miniaturization is to shorten the wavelength (increase the energy) of the exposure light source. Specifically, ultraviolet rays such as g-line and i-line have traditionally been used, but mass production of semiconductor elements using KrF excimer lasers and ArF excimer lasers has now begun. Furthermore, research is also being conducted on EUV (extreme ultraviolet), EB (electron beam), X-rays, and other light sources with shorter wavelengths (higher energy) than these excimer lasers.

[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 can form 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 with a specific molar absorption coefficient and employs a polymer compound having multiple structural units with a specific structure. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2023 / 127692 Summary of the Invention [Problem to be solved by the invention]

[0007] As lithography technology continues to advance and resist patterns become increasingly finer, resist compositions are required to have the resolution necessary to reproduce patterns with finer dimensions, as well as lithography properties such as good resist pattern shape and excellent DOF margin.

[0008] The present invention has been made in light of the above-mentioned circumstances, and an object of the present invention is to provide a compound, an acid generator, a resist composition, and a method of forming a resist pattern that are capable of forming a resist pattern that satisfies all of the following: high resolution that enables the reproduction of patterns with fine dimensions, a favorable resist pattern shape, and an excellent DOF margin. [Means for solving the problem]

[0009] As a result of extensive research conducted by the present inventors in order to solve the above-mentioned problems, they discovered that, by using the following configurations, it is possible to obtain a compound, an acid generator, a resist composition, and a method of forming a resist pattern that are capable of forming a resist pattern that satisfies all of the following requirements: a resolution that enables the reproduction of patterns with fine dimensions, a favorable resist pattern shape, and an excellent DOF margin, and they have 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, The composition contains a base component (A1) whose solubility in a developer changes under the action of an acid, and an acid generator component (B) that generates an acid upon exposure to light, The acid generator component (B) includes a compound represented by the following general formula (b-1).

[0011] [ka]

[0012] In the general formula (b-1), Ra represents an arbitrary organic group. 01 Rb is an aryl group which may have a substituent. 02 , and Rb 03 Rb each independently represents 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 is a single bond or a divalent linking group.

[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), 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): The crosslinking agent (C) includes 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.

[0014] [ka]

[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 equal to or greater than 1.

[0016] [ka]

[0017] In the general formula (b-1), Ra represents an arbitrary organic group. 01 Rb is an aryl group which may have a substituent. 02 , and Rb 03 Rb each independently represents 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 is a single bond or a divalent linking group.

[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, comprising 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 compound according to the fourth embodiment of the present invention is represented by the above general formula (b-1).

[0020] The acid generator according to the fifth embodiment of the present invention contains a compound represented by the above general formula (b-1). [Effects of the Invention]

[0021] The present invention is able to provide a compound, an acid generator, a resist composition, and a method of forming a resist pattern that are capable of forming a resist pattern that satisfies all of the following: a high resolution that enables the reproduction of patterns with fine dimensions, a favorable resist pattern shape, and an excellent DOF margin. DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes in detail the embodiments of the present invention, but the present invention is not limited to the embodiments described below.

[0023] In the present disclosure, the term "aliphatic" is a relative concept to aromatic, and is defined as meaning a group, compound, etc. that does not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, the term "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. The term "fluorinated alkyl group" or "fluorinated alkylene group" refers to an alkyl group or alkylene group in which some or all of the hydrogen atoms have been substituted with fluorine atoms. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). The phrase "optionally substituted" includes both cases where a hydrogen atom (-H) is replaced with a monovalent group and cases where a methylene group (-CH2-) is replaced with a divalent group. The term "exposure" is a general concept that includes irradiation with radiation.

[0024] 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 with 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 with 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 using GPC (gel permeation chromatography).

[0025] 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.

[0026] The term "structural unit derived from an acrylate ester" refers to a structural unit formed by cleavage of the ethylenic double bond of an acrylate ester. An "acrylic acid ester" is a compound in which the hydrogen atom at the terminal carboxyl group of acrylic acid (CH2=CH-COOH) is substituted with an organic group. In the acrylic acid ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. 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. In addition, the acrylic acid ester has a substituent (R 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 has been 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."

[0027] A "structural unit derived from hydroxystyrene" refers to a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene. A "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" refers to a hydroxystyrene in which the hydrogen atom at the α-position is substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include hydroxystyrene in which the hydrogen atom at the α-position may be substituted with a substituent, but the hydrogen atom of the hydroxyl group is substituted with an organic group; and hydroxystyrene in which the hydrogen atom at the α-position may be substituted with a substituent, but a substituent other than a hydroxyl group is bonded to the benzene ring. Unless otherwise specified, the α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded. Examples of the substituent that substitutes the hydrogen atom at the α-position of the hydroxystyrene include the same groups as those exemplified as the substituent at the α-position in the above-mentioned α-substituted acrylic ester.

[0028] 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 group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group), etc. Specific examples of the halogenated alkyl group as a substituent at the α-position include groups in which some or all of the hydrogen atoms of the above-mentioned "alkyl group as a substituent at the α-position" 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. Specific examples of the hydroxyalkyl group 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.

[0029] In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. Furthermore, in the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the corresponding substances present in the composition, unless otherwise specified. Furthermore, chemical structural formulae in this disclosure may be written as simplified structural formulae in which hydrogen atoms are omitted. In this disclosure, some structures represented by chemical formulas may have asymmetric carbon atoms, and may exist as enantiomers or diastereomers. In such cases, a single chemical formula represents all isomers. These isomers may be used alone or as a mixture. In the present disclosure, "% by mass" and "% by weight" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0030] [Resist Composition] In the present disclosure, a resist composition that forms a positive resist pattern by dissolving and removing exposed portions of the 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 the 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 an alkaline development process in which an alkaline developer is used in the development treatment during resist pattern formation, or may be for a solvent development process in which a developer containing an organic solvent (organic developer) is used in the development treatment. In other words, the resist composition of this embodiment is a "positive resist composition for an alkaline developing process" that forms a positive resist pattern in an alkaline developing process, and a "negative resist composition for a solvent developing process" that forms a negative resist pattern in a solvent developing process.

[0031] 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. The resist composition contains a base component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes due to the action of the 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) contains a compound represented by the following general formula (b-1):

[0032] A resist composition according to a second embodiment of the present invention comprises a base component (A2) (hereinafter also referred to as “component (A2)”) containing an alkali-soluble resin (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 crosslinkers, urea-based crosslinkers, alkylene urea-based crosslinkers, glycoluril-based crosslinkers, and epoxy-based crosslinkers.

[0033] 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, 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. However, 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. Therefore, when the resist film is developed, the exposed portions of the resist film are dissolved and removed, forming a positive resist pattern.

[0034] When a resist film formed using the resist composition according to the second embodiment of the present invention is exposed to light, an acid is generated from component (B). This acid reacts with component (C) and a crosslinking reaction occurs, reducing the solubility of the resist film in a developer. Therefore, when a resist film obtained by applying the resist composition according to the second embodiment to a substrate is selectively exposed to light in the formation of a resist pattern, 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 developed with an alkali or solvent, the unexposed portions of the resist film are dissolved and removed, forming a negative resist pattern. This allows for the formation of a desired resist pattern with high precision by selectively exposing the resist film through a desired mask pattern. The resist composition according to the second embodiment of the present invention may be used for an alkaline development process in which an alkaline developer is used for the development treatment during resist pattern formation, or may be used for a solvent development process in which a developer containing an organic solvent (organic developer) is used for the development treatment during resist pattern formation. The resist composition according to the second embodiment of the present invention is particularly useful for an alkaline development process.

[0035] [Resist composition according to the 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. Such a polymeric compound can be a copolymer having a structural unit that generates an acid upon exposure. Examples of structural units that generate an acid upon exposure include known ones.

[0036] The resist composition according to the first embodiment of the present invention contains a compound represented by general formula (b-1) described below as the acid generator component (B).

[0037] In the compound represented by general formula (b-1) according to the first embodiment of the present invention, the anion is stabilized by 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.

[0038] 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 contains 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 a resin (A1) is used, and other polymeric compounds and / or low molecular weight compounds may be used in combination with the resin (A1).

[0039] The resin (A1) preferably contains a structural unit (a10) represented by general formula (a10-1). It may also contain a polymeric compound having a structural unit (a1) that contains an acid-decomposable group whose polarity increases when exposed to acid. The resin (A1) may contain, in addition to the structural unit (a10), a polymeric compound that further contains a structural unit (a1) that contains 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.

[0040] In the resist composition according to the first embodiment of the present invention, the resin (A1) may be used alone or in combination of two or more different types.

[0041] <Constituent unit (a10)> The resin (A1) preferably has a structural unit (a10) represented by general formula (a10-1).

[0042] [ka]

[0043] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.] x1 is a single bond or a divalent linking group. x1 is (n ax1 +1)valent aromatic hydrocarbon group. ax1 is an integer greater than or equal to 1.]

[0044] 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.

[0045] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya 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.

[0046] 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.

[0047] Ya x1 Aliphatic hydrocarbon groups in 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 a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in its structure.

[0048] Linear or branched aliphatic hydrocarbon groups 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 straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0049] 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.

[0050] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in its structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0051] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and still more preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being 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 have been substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0052] Ya x1 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. 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 the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle 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 hydrogen atom has been further 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 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0053] The aromatic hydrocarbon group may have a hydrogen atom 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 the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0054] Divalent linking groups containing heteroatoms: Ya x1 is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2-, -S(=O)2-O-, and groups represented by the formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or- Y 21 -S(=O)2-OY 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.

[0055] 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, an acyl group, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. Formula-Y21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - and -Y 21 -S(=O)2-OY 22 -Medium, 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 groups as those (divalent hydrocarbon groups which may have a substituent) mentioned in the description of the divalent linking group in the above. Ya 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.

[0056] 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. Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -OC(=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-, -OC(=O)-], and even more preferably a single bond.

[0057] In the formula (a10-1), Wa x1 is (n ax1 +1)valent aromatic hydrocarbon group. Wa x1The 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 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. Also, Wa x1 The aromatic hydrocarbon group in the formula (n) may be an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1 As examples, benzene, naphthalene, anthracene, or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed from benzene or naphthalene is preferred. ax1 A group obtained by removing (n +1) hydrogen atoms from benzene is more preferred. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0058] Wa x1 The 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 on the cyclic aliphatic hydrocarbon group in Wa include those listed above. x1 However, from the aromatic ring (n ax1 +1) hydrogen atoms from the aromatic ring,ax1 +1) hydrogen atoms are substituted for the hydrogen atoms in the group obtained by removing the hydrogen atoms. 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.

[0059] 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, further preferably 1, 2 or 3, and particularly preferably 1 or 2. ax1 is preferably 1.

[0060] Specific examples of the structural unit (a10) represented by the formula (a10-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0061] [ka]

[0062] [ka]

[0063] [ka]

[0064] [ka]

[0065] The structural unit (a10) 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 (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 as large as the lower limit of the above range, sensitivity can be further improved, while by ensuring that the proportion is at most the upper limit, it is easier to achieve a balance with other structural units.

[0066] <Constituent unit (a1)> The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases upon the action of an acid. The term "acid-decomposable group" refers to a group having acid decomposability in which at least some of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that decompose under the action of an acid to generate a polar group. Examples of polar groups include a carboxy group, a hydroxy group, an amino group, a sulfo group (-SO3H), etc. Among these, a polar group containing -OH in the structure (hereinafter sometimes referred to as an "OH-containing polar group") is preferred, a carboxy group or a hydroxy group is more preferred, and a carboxy group is particularly preferred. More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group). Here, the term "acid-dissociable group" refers to either (i) a group having acid dissociability such that the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (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 an 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. Thus, when the acid-dissociable group dissociates under the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, 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.

[0067] 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. The acid-decomposable group (acid-dissociable group) in the structural unit (a1) has an appropriate bulkiness, which makes it possible to appropriately control acid diffusion and adjust solubility in a developer, thereby reducing roughness when forming a resist pattern. Examples of the acid-dissociable group within the structural unit (a1) include those groups that have been proposed as acid-dissociable groups for base resins used in chemically amplified resists. Specific examples of acid-dissociable groups that have been proposed for use in 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."

[0068] 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 groups").

[0069] [ka]

[0070] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group.3 is a hydrocarbon group, and Ra' 3 Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.]

[0071] In formula (a1-r-1), Ra' 1 and Ra' 2 At least one of these is preferably a hydrogen atom, and both are more preferably hydrogen atoms. Ra' 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 an alkyl group having 1 to 5 carbon atoms is preferred. Specific examples include linear or branched alkyl groups. More specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups, with methyl and ethyl being more preferred, and methyl being particularly preferred.

[0072] In formula (a1-r-1), Ra' 3 Examples 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, an n-pentyl group, etc. Among 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.

[0073] 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, and is preferably an isopropyl group.

[0074] 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. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. 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 preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0075] Ra' 3 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and 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 heterocycle include pyridine rings and thiophene rings. Ra' 3Specific examples of the aromatic hydrocarbon group in the formula (I) include a group (aryl group or heteroaryl group) in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle; 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., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0076] Ra' 3 The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (hereinafter these substituents are collectively referred to as "Ra 05 ") are also examples. where R P1 is a monovalent linear 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 P2Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group, and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents, or may have one or more of each of multiple 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; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0077] Ra' 3 But Ra' 1 , Ra' 2 When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0078] Tertiary alkyl ester-type acid-labile group: Among the polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group may be referred to as "tertiary alkyl ester-type acid-dissociable groups" hereinafter for convenience.

[0079] [ka]

[0080] [In the formula, Ra' 4 ~Ra' 6 Each represents a hydrocarbon group, and Ra' 5 , Ra' 6 may be bonded to each other to form a ring.

[0081] Ra' 4 Examples of the hydrocarbon group represented by include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. Ra' 4 The linear or branched alkyl group and the cyclic hydrocarbon group (the monocyclic aliphatic hydrocarbon group, the polycyclic aliphatic hydrocarbon group, and the aromatic hydrocarbon group) in 3 Examples of the alkyl group include the linear or branched alkyl group and the cyclic hydrocarbon group mentioned above. Ra' 4 The chain or cyclic alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 The hydrocarbon group of Ra' 3 The hydrocarbon groups are the same as those listed above.

[0082] Ra' 5 and Ra' 6 and (a1-r-2) are bonded to each other to form a ring, suitable examples of the acid-dissociable group represented by the above formula (a1-r-2) include a group represented by the following formula (a1-r2-1), a group represented by the following formula (a1-r2-2), and a group represented by the following formula (a1-r2-3): On the other hand, Ra' 4 ~Ra' 6When the groups are not bonded to each other but are independent hydrocarbon groups, suitable examples of the acid-dissociable group represented by the above formula (a1-r-2) include groups represented by the following formula (a1-r2-4):

[0083] [ka]

[0084] [In formula (a1-r2-1), Ra 031 represents an alkyl group, and Yab 0 represents a carbon atom. 0 Yab 0 represents a group which forms an alicyclic hydrocarbon group together with Ya, and some or all of the hydrogen atoms of 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 of 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 these 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 which 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 in this chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * indicates a bond.]

[0085] In the above formula (a1-r2-1), Ra 031is 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.

[0086] Ra 031 The linear alkyl group in the formula (I) has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra 031 In the formula (I), the branched alkyl group is the above-mentioned Ra' 4 The same can be mentioned.

[0087] Ra 031 The alkyl group in 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 (e.g., methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. Examples of heteroatoms include oxygen, sulfur, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0088] In formula (a1-r2-1), Xab 0 Yab 0 The alicyclic hydrocarbon group formed together with 3 Preferred 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. 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 more preferred. The monocycloalkane is preferably one having 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane, cycloheptane, cyclooctane, etc.

[0089] 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 such groups include groups in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) shown above. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. The substituent may be any of the above-mentioned Ra' 4 Examples of the substituents include the same as those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 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. Ra 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, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, and cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl group, tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and adamantyl group. Ra 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 preferred, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferred, with a hydrogen atom being particularly preferred.

[0090] 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: 05 The same groups as those shown below can be mentioned.

[0091] 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.

[0092] In the formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is the same as Ra' in the above formula (a1-r-2). 4 Preferred are groups in which one or more hydrogen atoms have been further removed from the groups listed as the aliphatic hydrocarbon groups, which are monocyclic or polycyclic groups. In formula (a1-r2-3), Ra 104 Examples of the aromatic hydrocarbon group in the formula 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.

[0093] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed by include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), and an alkyloxycarbonyl group.

[0094] In formula (a1-r2-4), Ra' 12 and Ra' 13are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. 12 and Ra' 13 In the formula, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned Ra 101 ~Ra 103 Examples include the same monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms as in the chain saturated hydrocarbon group in the above. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, alkyl groups having 1 to 5 carbon atoms are more preferred, with methyl and ethyl groups being even more preferred, and methyl groups being particularly preferred. The above Ra' 12 and Ra' 13 When the chain saturated hydrocarbon group represented by the formula: is substituted, examples of the substituent include the above-mentioned Ra 05 The same groups as those shown below can be mentioned.

[0095] In formula (a1-r2-4), Ra' 14 Ra' 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.

[0096] 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, an n-pentyl group, etc. Among 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.

[0097] Ra' 14The branched alkyl group in the formula (I) preferably has 3 to 10 carbon atoms, 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, with an isopropyl group being preferred.

[0098] 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 preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. 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 preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0099] 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. Ra' 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.

[0100] Ra' in formula (a1-r2-4) 14 When is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. Ra' in formula (a1-r2-4) 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, or 9th position of the anthryl group.

[0101] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0102] [ka]

[0103] [ka]

[0104] [ka]

[0105] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0110] [ka]

[0111] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0112] [ka]

[0113] Tertiary alkyloxycarbonyl acid dissociating group: Among the polar groups, examples of the acid-dissociable group that protects the hydroxyl 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").

[0114] [ka]

[0115] [In the formula, Ra' 7 ~Ra' 9 Each represents an alkyl group.

[0116] In formula (a1-r-3), Ra' 7 ~Ra' 9 and each are 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.

[0117] 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.

[0118] Specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1).

[0119] (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).

[0120] [ka]

[0121] [wherein 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. 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.]

[0122] In the formula (a1-1), the alkyl group of 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group of 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 of 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group of 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 is most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

[0123] In the formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Va1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0124] 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 straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0125] Examples of the aliphatic hydrocarbon group containing a ring in its structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same as the straight-chain aliphatic hydrocarbon group or the branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably 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 thereof 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 specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0126] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such aromatic hydrocarbon groups preferably have 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 substituents. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the 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).

[0127] In the formula (a1-1), n a1 is an integer from 0 to 2. a1 is preferably 0 or 1, and more preferably 0.

[0128] The formula (a1-1) is preferably the following formula (a1-2).

[0129] [ka]

[0130] (In the 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. na3 represents an integer of 0 to 2. Ra 031 represents an alkyl group, and Yab 0 represents a carbon atom. 0 Yab 0and represents a group which forms an alicyclic hydrocarbon group together with the group (a), and some or all of the hydrogen atoms of this alicyclic hydrocarbon group may be substituted.

[0131] In general formula (a1-2), R, Va 3 is R in formula (a1-1), Va 1 and the same respectively.

[0132] In general formula (a1-2), na3 represents an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0133] In general formula (a1-2), Ra 031 , Xab 0 , Yab 0 is the Ra in formula (a1-r2-1). 031 , Xab 0 , Yab 0 and the same respectively.

[0134] 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.

[0135] Specific examples of the structural unit (a1) are listed below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0136] [ka]

[0137] [ka]

[0138] [ka]

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] The structural unit (a1) that the resin (A1) may have may be of one type, or may be of two or more types. In the resin (A1), the proportion of the structural unit (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 least as large as the lower limit of the above-mentioned preferred range, lithography properties such as high sensitivity, resolution, and improved roughness can be achieved. By ensuring that the proportion is at most the upper limit, a balance with other structural units can be achieved, resulting in various favorable lithography properties.

[0147] <Constituent 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.

[0148] 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.

[0149] 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.

[0150] Examples of the substituent that substitutes the hydrogen atom at the α-position of styrene include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group 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 further preferably a methyl group from the viewpoint of industrial availability.

[0151] Examples of the substituent that substitutes the hydrogen atom on the benzene ring of styrene include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. It's nice. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and still more preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being 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 have been substituted with the halogen atoms. The substituent substituting the hydrogen atom 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.

[0152] 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.

[0153] The structural unit (st) contained in the resin (A1) may be of one type or 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).

[0154] <Constituent unit (a20)> The resin (A1) may further include a structural unit (a20) in addition to the structural unit (a10). The structural unit (a20) is a structural unit represented by the following general formula (a20-1).

[0155] [ka]

[0156] [In the formula, R x2 represents 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.

[0157] In the above 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. R 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, and from the viewpoint of industrial availability, more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0158] In the formula (a20-1), Ya x2 is a divalent linking group. In the formula (a20-1), Ya x2The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Examples of the divalent hydrocarbon group which may have a substituent and the divalent linking group which contains 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.

[0159] In the formula (a20-1), Ya x2 Among the above, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof is preferred, and an ester bond [-C(=O)-O-, -OC(=O)-] is more preferred.

[0160] In the formula (a20-1), Ra x2 is an aliphatic hydrocarbon group. x2 The aliphatic hydrocarbon group includes 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.

[0161] 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.

[0162] The cyclic aliphatic hydrocarbon group 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 preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.

[0163] 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, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0164] 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. In addition, Ra x2 The aliphatic hydrocarbon group in is an unsubstituted aliphatic hydrocarbon group, and Ra x2 In 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.

[0165] 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.

[0166] Specific examples of the structural unit (a20) represented by the above 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.

[0167] [ka]

[0168] Of the above, the structural unit (a20) is preferably a structural unit represented by any one of the above general formulas (a20-01-1), (a20-01-3), (a20-01-4), or (a20-02-1), and more preferably a structural unit represented by any one of the above general formulas (a20-01-1), (a20-01-4), or (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 one type, or 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 from 2 to 70 mol%, more preferably from 3 to 60 mol%, even more preferably from 5 to 50 mol%, and particularly preferably from 10 to 40 mol%.

[0169] <Other constituent units> The resin (A1) may include structural units other than the above-mentioned structural unit (a10), structural unit (a1), structural unit (st), and structural unit (a20). Examples of other structural units include structural units (a2) containing a lactone-containing cyclic group, an -SO2- containing cyclic group, or a carbonate-containing cyclic group, and structural units (a3) ​​containing a polar group-containing aliphatic hydrocarbon group. Many structural units that are conventionally known as those used in resin components of resist compositions can be used as the structural units (a2) and (a3).

[0170] The weight average molecular weight (Mw) of the 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 the component (A1) is less than or equal to the preferred upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is at least the preferred lower limit of this range, the compound exhibits good dry etching resistance and the cross-sectional shape of the resist pattern. The dispersity (Mw / Mn) of the component (A1) is not particularly limited, but is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.5, where Mn represents the number average molecular weight.

[0171] (Resist composition according to the second embodiment) 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), 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): The crosslinking agent (C) includes 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.

[0172] [ka]

[0173] 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 equal to or greater than 1.

[0174] [ka]

[0175] In the general formula (b-1), Ra represents an arbitrary organic group. 01 Rb is an aryl group which may have a substituent. 02 , and Rb 03 Rb each independently represents 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 is a single bond or a divalent linking group.

[0176] ≪(A2) Component≫ In the resist composition according 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 unit (a10) as in the resist composition according to the first embodiment described above.

[0177] The structural unit (a10) 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 (a10), the proportion of the structural unit (a10) relative to the total (100 mol %) of all structural units constituting the resin (A2) is preferably 40 to 100 mol %, more preferably 50 to 100 mol %, and even more preferably 60 to 100 mol %.

[0178] The resin (A2) may contain, in addition to the structural unit (a10), at least one structural unit selected from the structural unit represented by general formula (a20-1) above (structural unit (a20)) and the 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 the structural unit (st) in the resist composition according to the first embodiment described above.

[0179] The structural unit (st) contained in the resin (A2) may be of one type or 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).

[0180] 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) within the resin (A2) is preferably within a range from 2 to 70 mol %, more preferably from 3 to 60 mol %, even more preferably from 5 to 50 mol %, and particularly preferably from 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 as large as the above preferred lower limit, the DOF and pattern shape can be further improved. On the other hand, by ensuring that the proportion of the structural unit (a20) is at most the above preferred upper limit, resolution can be further improved. The structural unit (a20) contained in the resin (A2) may be of one type, or may be of two or more types.

[0181] Other structural units The resin (A2) may include structural units other than the above-mentioned structural unit (a10), structural unit (st), and structural unit (a20). Examples of other structural units include a structural unit (a1) containing a protecting group, a structural unit (a2) containing a lactone-containing cyclic group, an -SO2- containing cyclic group, or a carbonate-containing cyclic group, and a structural unit (a3) ​​containing a polar group-containing aliphatic hydrocarbon group. Many of the structural units (a1), (a2), and (a3) ​​that are conventionally known as those used in resin components of resist compositions can be used.

[0182] In the resist composition according to the second embodiment of the present invention, the component (A2) may use either a single type of compound, or a combination of two or more different types.

[0183] The weight average molecular weight (Mw) of the 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 the component (A2) is less than or equal to the preferred upper limit of this range, the compound will have sufficient solubility in resist solvents and alkaline developers for use as a resist, while when it is at least the preferred lower limit of this range, the compound will have good dry etching resistance and the cross-sectional shape of the resist pattern. The dispersity (Mw / Mn) of the component (A2) is not particularly limited, but is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.0, where Mn represents the number average molecular weight.

[0184] Acid generator component (component (B)) The resist composition according to the first embodiment of the present invention and the resist composition according to the second embodiment of the present invention (hereinafter sometimes simply referred to as the resist composition) each contain an acid generator component (B) (hereinafter sometimes referred to as the “component (B)”) that generates acid upon exposure, and the acid generator component (B) includes an acid generator (B1) (hereinafter sometimes referred to as the “component (B1)”) that is a compound represented by the following general formula (b-1):

[0185] [ka]

[0186] In the general formula (b-1), Ra represents an arbitrary organic group. 01 Rb is an aryl group which may have a substituent. 02 , and Rb 03 Rb each independently represents 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 is a single bond or a divalent linking group.

[0187] [Anion part (C6F5-SO2-N - -SO2-Ra] In the formula (b-1), Ra represents an arbitrary organic group. The organic group in the arbitrary organic group includes a monovalent hydrocarbon group which may have a substituent. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0188] Aliphatic hydrocarbon groups in Ra The aliphatic hydrocarbon group 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 a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in its structure.

[0189] Linear or branched aliphatic hydrocarbon groups Examples of the linear or branched aliphatic hydrocarbon group include alkyl groups, alkenyl groups, and alkynyl groups. Examples of the alkyl group 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 groups. Examples of the alkenyl group 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 groups. Examples of the alkynyl group 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 groups.

[0190] 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.

[0191] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group, a group in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the alicyclic hydrocarbon group include 3- to 8-membered cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups; 3- to 8-membered cycloalkenyl groups such as cyclopentenyl and cyclohexenyl groups; and bridged cyclic hydrocarbon groups having 4 to 20 carbon atoms (preferably 7 to 12 carbon atoms) such as adamantyl and norbornyl groups.

[0192] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or 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, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being 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 have been substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0193] Aromatic hydrocarbon groups in Ra The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The 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 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 the aromatic heterocycle include a pyridine ring and a thiophene ring. 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 group or heteroaryl group); 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 to 2, and particularly preferably 1.

[0194] The aromatic hydrocarbon group may have a hydrogen atom 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, a halogenated alkoxy group, a hydroxyl group, a carbonyl group, and a nitro group. A halogen atom, a halogenated alkyl group, or a halogenated alkoxy group is preferred. 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, an n-propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group. 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.

[0195] 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, an alkoxy group, a hydroxyl group, a carbonyl group, a nitro group, or a halogenated alkoxy group. 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 iso-propyl 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 above alkyl groups have been substituted with halogen atoms, and groups in which all of the hydrogen atoms of the above alkyl groups have been substituted with halogen atoms are preferred. Examples of halogenated alkoxy groups include the above alkoxy groups in which some or all of the hydrogen atoms have been substituted with halogen atoms, and preferred are alkoxy groups in which all of the hydrogen 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 preferred. The aryl group includes an aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred.

[0196] 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.

[0197] [ka]

[0198] [Cation part: Rb 01 -Lb 01 -S+(Lb 02 )-(Lb 03 )] In the general formula (b-1), Rb 01 represents an aryl group which may have a substituent. Rb 02 , and Rb 03are each independently 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. Rb 02 and Rb 03 may be bonded to form a ring together with the sulfur atom in the formula. Lb 01 is a single bond or a divalent linking group.

[0199] Rb 01 The aryl group in is preferably an aryl group having 6 to 20 carbon atoms, more preferably a phenyl group or a naphthyl group.

[0200] Rb 01 Examples of the substituent that the aryl group in the formula (I) may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, a hydroxyl group, a nitro 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 hydrocarbon group).

[0201] Rb 02 ~Rb 03 The alkyl group in the formula (I) may be a chain or cyclic alkyl group, and is preferably an alkyl group having 1 to 30 carbon atoms. Rb 01 ~Rb 03 The alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms.

[0202] Rb 02 ~Rb 03 Examples of the substituent that the alkyl group and alkenyl group in the formula (I) may have 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 hydrocarbon group).

[0203] 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-, -OC(=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.

[0204] In the general formula [-Yca0-Rca0], the hydrocarbon group for Rca0 can be the same as the hydrocarbon group for Ra above, and is preferably an aliphatic hydrocarbon group, more preferably a linear or branched aliphatic hydrocarbon group or an aliphatic hydrocarbon group containing a ring in its structure.

[0205] Examples of the group represented by the general formula [-Yca0-Rca0] include groups represented by the following formulae (ca-r-1) to (ca-r-7).

[0206] [ka]

[0207] [In the formula, R' 201 are each independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

[0208] R' 201 The optionally substituted cyclic group represented by the formula (I) 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 aromatic hydrocarbon rings and aryl groups in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings, with phenyl and naphthyl groups being preferred. Examples of the aliphatic hydrocarbon group include groups in which one hydrogen atom has been removed from a monocycloalkane or polycycloalkane, and preferred are a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantyl group, and a norbornyl group.

[0209] R' 201 The optionally substituted chain alkyl group represented by may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10. 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 heneicosyl group, and a docosyl group.

[0210] R' 201 The 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, still 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. As the chain alkenyl group, among the above, a propenyl group is particularly preferred.

[0211] 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.

[0212] R' 201Examples of the substituent in the cyclic group, chain alkyl group, or chain 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. The alkyl group as a substituent is preferably an alkyl group having 1 to 6 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, tert-butyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, or cyclohexyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being 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.

[0213] Rb 02 and Rb 03 In the formula, some of the carbon atoms may be substituted with heteroatoms, and when they are bonded to each other to form a ring together with the sulfur atom in the formula, heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, carbonyl groups, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R Nis 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.

[0214] In the general formula (b-1), Rb 01 Among the above, is more preferably 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 hydrocarbon group).

[0215] In the general formula (b-1), Rb 02 and Rb 03 Among the above, Rb is preferably bonded to each other to form a ring together with the sulfur atom in the formula. 02 and Rb 03 more preferably bonded to each other to form an aliphatic ring together with the sulfur atom in the formula, and further preferably form a tetrahydrothiophene ring or a thiane ring.

[0216] In the general formula (b-1), Lb 01 is a single bond or a divalent linking group. Lb 01 The divalent linking group in is preferably a carbonyl group (-CO-), an ester bond [-C(=O)-O-, -OC(=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 a carbonyl group (-CO-) and a linear or branched alkylene group. Specific examples of groups formed by combining a carbonyl group (—CO—) with a linear or branched alkylene group include groups represented by the general formula [*-Yca1-Yca2-**] (Yca1 is a linear or branched alkylene group, and is a carbonyl group (—CO—). * represents a bond to the sulfur atom in the general formula (b-1). ** represents a bond to Rb in the general formula (b-1). 01 ) are examples of bonds with .

[0217] The compound represented by the above general formula (b-1) is preferably a cation represented by the following general formula (b-2).

[0218] [ka]

[0219] In the general formula (b-2), Ra represents an arbitrary organic group. 01 is an aryl group which may have a substituent. 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 is a single bond or a divalent linking group.

[0220] Ra in the general formula (b-2) is the same as Ra in the general formula (b-1).

[0221] Rb in general formula (b-2) 01 represents Rb in the general formula (b-1). 01 is the same as

[0222] Lb in general formula (b-2) 01 represents Lb in the general formula (b-1). 01 is the same as

[0223] Yb in general formula (b-2) 01is 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 (b-1). 01 Examples of the substituents include the same as those that may be possessed by the group. Yb in general formula (b-2) 01 is preferably a group which forms a tetrahydrothiophene ring or a thiane ring together with the sulfur atom in the formula.

[0224] The compound represented by the above general formula (b-2) is preferably a compound represented by the following general formula (b-3).

[0225] [ka]

[0226] [In the general formula (b-3), Ra is an arbitrary organic group. X + is a cation represented by the following formula (X-1) or (X-2):

[0227] [ka]

[0228] [In the formula, Rb 01 is an aryl group which may have a substituent. 01 is a group that forms an aliphatic ring together with the sulfur atom in the formula. 01 The aliphatic ring formed by R may contain an ether bond and may have a substituent. 11 ~R 15 R are each independently a hydrogen atom, a halogen atom, a hydrocarbon group which may have a substituent, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group. 11 ~R 15 Any two or more of R may be bonded to each other to form a ring. 21 , R22 R are each independently a hydrogen atom, a halogen atom, a cyano group, or a hydrocarbon group which may have a substituent. 21 and R 22 may be bonded to each other to form a ring.

[0229] Rb in formula (X-1) 01 represents Rb in the general formula (b-1). 01 is the same as

[0230] Yb in formula (X-1) 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 (b-1). 01 Examples of the substituents include the same as those that may be possessed by the group. Yb in formula (X-1) 01 is preferably a group which forms a tetrahydrothiophene ring or a thiane ring together with the sulfur atom in the formula.

[0231] R in formula (X-2) 11 ~R 15 Examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferred. R in formula (X-2) 11 ~R 15 Examples of the hydrocarbon group constituting the optionally substituted hydrocarbon group, alkoxy group, aryloxy group, alkoxycarbonyl group, alkylcarbonyloxy group, cycloalkylcarbonyloxy group, alkylthio group, or arylthio group represented by the formula (I) include the same hydrocarbon groups as those represented by the formula (I) and (II).

[0232] Specific examples of the cation moiety of component (B) are shown below, but are not limited to these.

[0233] [ka]

[0234] [ka] (ca-01-12)(ca-01-13)(ca-01-14)

[0235] [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 (ca-r-1) to (ca-r-7).

[0236] As the cation portion of component (B), among the above, 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 preferred, and a cation represented by any one of chemical formulas (ca-01-1) to (ca-01-3), and (ca-01-11) is more preferred.

[0237] Specific examples of suitable components (B) are listed below.

[0238] [ka]

[0239] [ka]

[0240] In the resist composition of this embodiment, the component (B) may be used either as a single type, or in combination of two or more types. In the resist composition of this embodiment, the amount of the component (B) relative to 100 parts by mass of the component (A) (meaning the component (A1) or the 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, lithography properties such as resolution, resist pattern shape, and DOF margin are further improved during resist pattern formation. On the other hand, when the amount is no more than the upper limit of the aforementioned preferred range, a homogeneous solution is more 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.

[0241] About ingredient (B2) The resist composition of this embodiment may also contain an acid generator component (hereafter referred to as “component (B2)”) other than the component (B) above, as long as the effects of the present invention are not impaired. There are no particular restrictions on the component (B2), and any of the compounds 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.

[0242] In the resist composition of this embodiment, the component (B2) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (B2), the amount of the component (B2) in the resist composition is preferably no more than 50 parts by mass, 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 (A). By ensuring that the amount of the component (B2) falls within this 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, and the storage stability of the resist composition is also favorable.

[0243] <(C) component> 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.

[0244] 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.

[0245] 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.

[0246] The alkylene urea crosslinking agent may be a compound represented by the following general formula (CA-1).

[0247] [ka]

[0248] [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 4are each independently a hydrogen atom, a hydroxyl group or a lower alkoxy group, and vc is an integer of 0 to 2.

[0249] 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, and are more preferably the same. Rc 3 and Rc 4 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. 3 and Rc 4 may be the same or different from each other, and are more preferably the same. vc is an integer of 0 to 2, 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.

[0250] The compound represented by the above general formula (CA-1) can be obtained by condensing alkylene urea with formalin and then reacting the resulting product with a lower alcohol.

[0251] Specific examples of alkylene urea-based crosslinking agents 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.

[0252] 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-based 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.

[0253] 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 crosslinking agents are listed below.

[0254] [ka]

[0255] Among these, as component (C), a crosslinking agent having an -NCH2-OCH3 group is preferred, and a crosslinking agent selected from the group consisting of a compound represented by the following formula (c1-1) or (c1-2), a compound having an -NCH2-OCH3 group and a melamine skeleton, and mono-, di-, tri-, and / or tetra-methoxymethylated glycoluril is more preferred, and a crosslinking agent selected from the group consisting of a compound having an -NCH2-OCH3 group and a melamine skeleton, and mono-, di-, tri-, and / or tetra-methoxymethylated glycoluril is even more preferred.

[0256] [ka]

[0257] [In the formula, nc1 and nc2 each independently represent an integer of 1 to 3.]

[0258] The component (C) may be used alone or in combination of two or more. 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 content of component (C) is at least the lower limit, crosslinking proceeds sufficiently, resulting in improved resolution and lithography properties. Furthermore, a good resist pattern with minimal swelling can be obtained. Furthermore, when the content is at most the upper limit, the storage stability of the resist composition is good, and deterioration of sensitivity over time is more easily suppressed.

[0259] <(D) component> The resist compositions according to the first and second embodiments of the present invention preferably further contain an acid diffusion controller component (hereafter 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 photodecomposable base (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of component (D1) and that decomposes upon exposure to light and loses its acid diffusion controllability. By using a resist composition that contains the 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), from the viewpoint of improving the transmittance of the resist film to an exposure light source when forming a thick-film resist pattern, the component (D1) is preferred.

[0260] Regarding component (D1) The component (D1) is a base component, and is a nitrogen-containing organic compound component that acts as an acid diffusion controller in the resist composition. The component (D1) is not particularly limited as long as it acts as an acid diffusion controller, and any known amine may be used. Among these, aliphatic amines or aromatic amines are preferred, and aliphatic amines are more preferred.

[0261] An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms. Aliphatic amines include amines in which at least one hydrogen atom of ammonia NH3 has been substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), or cyclic amines. Specific examples of alkylamines and alkyl alcoholamines 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 alcoholamines 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.

[0262] 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 the aliphatic monocyclic amine include piperidine and piperazine. The aliphatic polycyclic amine is preferably one having 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0263] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, and triethanolamine triacetate, with triethanolamine triacetate being preferred.

[0264] Furthermore, an aromatic amine may be used as the component (D1). Examples of aromatic amines include 4-dimethylaminopyridine, 2,6-di-tert-butylpyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, and N-tert-butoxycarbonylpyrrolidine.

[0265] The component (D1) may be used alone or in combination of two or more. When the resist composition contains the component (D1), the amount of the component (D1) in the resist composition is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A). By ensuring this range, the resist pattern shape and stability over time during storage can be improved.

[0266] Regarding component (D2) The component (D2) is not particularly limited as long as it decomposes upon exposure to light and loses its acid diffusion controllability, and does not fall under the category of component (D1), and any known compound may be used. When the resist composition contains the component (D2), which does not fall under the category of the above-mentioned component (D1), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern.

[0267] The component (D2) may be used as an acid generator in addition to or in place of the component (B).

[0268] 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)"), with the proviso that components (d2-1) to (d2-3) exclude those corresponding to general formula (b-1). The components (d2-1) to (d2-3) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion control properties (basicity), but act as quenchers in the unexposed areas of the resist film.

[0269] [ka]

[0270] [In the formula, Rd 1 ~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. 2 In this case, 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.

[0271] {(d2-1) component} Anion section 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' 201The same can be mentioned. Among these, Rd 1 As the substituent, an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkyl group which may have a substituent is preferable. 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-al-1) to (y-al-8).

[0272] [ka]

[0273] [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.]

[0274] 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.

[0275] 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). The aliphatic cyclic group is more preferably 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.

[0276] 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. Road 1 The alkyl group is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms, and particularly preferably 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).

[0277] Preferred examples of the anion moiety of the component (d2-1) are shown below.

[0278] [ka]

[0279] Cation part In formula (d2-1), M m+ is an m-valent organic cation. M m+The organic cation is preferably an onium cation, more preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and even more preferably a sulfonium cation or an iodonium cation. m is an integer of 1 or more.

[0280] Preferred cationic moieties ((M m+ ) 1 / m ) includes organic cations represented by any one of the following general formulas (ca-1) to (ca-3).

[0281] [ka]

[0282] [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, 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, and R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group, and L 201 represents -C(=O)- or -C(=O)-O-.]

[0283] R 201 ~R 207 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 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, an arylthio group, and a group represented by any one of the above formulas (ca-r-1) to (ca-r-7). The aryl group in the arylthio group as a substituent includes an aryl group having 6 to 20 carbon atoms, and is preferably a phenyl group, a naphthyl group, or a biphenyl group. Examples of the arylthio group include a phenylthio group, a naphthylthio group, and a biphenylthio group.

[0284] R 201 ~R 203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they may not contain a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, or a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable 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 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 tetrahydrothiopyranium ring, and a thioxanium ring.

[0285] 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 209When each of these independently represents an alkyl group, they may be bonded to each other to form a ring.

[0286] R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210 In the -SO2-containing cyclic group optionally having a substituent, the term "-SO2-containing cyclic group" refers to a cyclic group containing a ring containing -SO2- in its ring skeleton, specifically a cyclic group in which the sulfur atom (S) in -SO2- forms part of the ring skeleton of the cyclic group. The ring containing -SO2- in the ring skeleton is counted as the first ring, and if it is the only ring, it is called a monocyclic group, and if it has other ring structures, it is called a polycyclic group regardless of the structure. The -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2- containing cyclic group is preferably a cyclic group containing -O-SO2- in its ring skeleton, i.e., a cyclic group containing a sultone ring in which -OS- in -O-SO2- forms part of the ring skeleton.

[0287] Among the general formulas (ca-1) to (ca-3), the cation represented by formula (ca-1) is preferred.

[0288] Specific examples of suitable cations represented by formula (ca-1) include cations represented by any of the following formulas (ca-1-1) to (ca-1-70).

[0289] [ka]

[0290] [ka]

[0291] [ka]

[0292] [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.]

[0293] [ka]

[0294] [In the formula, R” 201 is a hydrogen atom or 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 the group

[0295] [ka]

[0296] 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).

[0297] [ka]

[0298] The component (d2-1) may be used alone or in combination of two or more.

[0299] {(d2-2) component} Anion section 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 The same can be mentioned. However, Rd 2 In this case, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not fluorinated), which makes the anion of component (d2-2) an appropriately weak acid anion, thereby improving the quenching ability of component (D). Road 2 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. The aliphatic cyclic group is more preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor, or the like. Road 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.

[0300] Preferred examples of the anion moiety of the component (d2-2) are shown below.

[0301] [ka]

[0302] Cation part In formula (d2-2), M m+ is an m-valent organic cation, and M in the formula (d2-1) m+is the same as: The component (d2-2) may be used alone or in combination of two or more.

[0303] {(d2-3) component} Anion section 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 The Rd is preferably a fluorine atom-containing cyclic group, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferred, and the Rd 1 The same fluorinated alkyl groups as those mentioned above are more preferred.

[0304] 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 The same can be mentioned. Among these, alkyl groups, alkoxy groups, alkenyl groups and cyclic groups which may have a substituent are preferred. Road 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 portion of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Road 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.

[0305] Road4 The 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.

[0306] Road 4 The cyclic group in the formula (I) is the same as the R' 201 Examples of the cyclic groups include those similar to those in the above, and preferred are alicyclic groups obtained by removing one or more hydrogen atoms 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.

[0307] In formula (d2-3), Yd 1 is a single bond or a divalent linking group. Yd 1 The divalent linking group in the formula (a10-1) is not particularly limited, but may be any of Ya x1 Examples of the divalent linking group include the same as those exemplified above.

[0308] Preferred examples of the anion moiety of the component (d2-3) are shown below.

[0309] [ka]

[0310] [ka]

[0311] Cation part In formula (d2-3), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d2-3) may be used alone or in combination of two or more.

[0312] The component (D2) may be any one of the components (d2-1) to (d2-3) above, or a combination of two or more of them. When the resist composition contains the component (D2), the amount of the component (D2) within the resist composition, relative to 100 parts by mass of the component (A), 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. When the amount of the component (D2) is at least as large as the lower limit of the preferred range, particularly good lithography properties and resist pattern shape are likely to be obtained, while when it is at most the upper limit, good sensitivity can be maintained and throughput is also excellent.

[0313] Manufacturing method of component (D2): The method for producing the components (d2-1) and (d2-2) is not particularly limited, and they can be produced by known methods. The method for producing component (d2-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0314] <Optional ingredients> The resist composition of this embodiment may further contain components (optional components) other than the above-mentioned components (A), (B), (C), and (D). Such optional components include, for example, the component (S) shown below.

[0315] <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 and forming a homogeneous solution, and any solvent that is appropriately selected from among those known to be conventionally used as solvents for chemically amplified resist compositions can be used. In the resist composition of this embodiment, the component (S) may 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.

[0316] Furthermore, a mixed solvent of PGMEA and a polar solvent is also preferred as component (S), and the blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and 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 which the mass ratio of the former to the latter is preferably 70:30 to 95:5. There are no particular restrictions on the amount of component (S) used, and it is set appropriately depending on the coating film thickness so as to provide a concentration that allows application to a substrate, etc. Generally, the component (S) is used so that the solids concentration of the resist composition falls within the range of 0.1 to 50 mass %, and preferably 0.2 to 45 mass %.

[0317] 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.

[0318] The resist composition of the first embodiment of the present invention contains the aforementioned components (A1) and (B), and, if necessary, the optional components described above. Suitable examples include resist compositions containing the component (A1), the component (B), and the component (D). Furthermore, suitable examples include resist compositions containing the component (A1), the component (B), the component (D), and the component (S).

[0319] The resist composition according to the second embodiment of the present invention contains the aforementioned components (A2), (B), and (C), and, if necessary, the optional components described above. Suitable examples include resist compositions containing the component (A2), the component (B), the component (C), and the component (D). Further suitable examples include resist compositions containing the component (A2), the component (B), the component (C), the component (D), and the component (S).

[0320] As explained above, the resist composition of this embodiment contains the acid generator component (B) containing the compound represented by the general formula (b-1) described above. The compound represented by the general formula (b-1) has anions stabilized by the electron-withdrawing effect of pentafluorobenzene, thereby increasing the acid strength (decreasing the pKa) and achieving high sensitivity.

[0321] (Method for forming a resist pattern) A method for forming a resist pattern according to another embodiment of the present invention is a method including 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 the resist pattern forming method is, for example, a resist pattern forming method carried out as follows.

[0322] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and then baked (post-apply bake (PAB)) at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably 50 to 90 seconds, 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 using a mask pattern, and then 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 subjected to a development treatment. In the case of an alkaline development process, the development treatment is performed as follows: An alkaline developer is used, and in the case of a solvent development process, a developer containing an organic solvent (organic developer) is used. After the development process, a rinse process is preferably carried out. In the case of an alkaline development process, the rinse process is preferably a water rinse using pure water, and in the case of a solvent development process, it is preferable to use a rinse solution containing an organic solvent. In the case of a solvent development process, the developing treatment or rinsing treatment may be followed by a treatment of removing the developing solution or rinsing solution adhering to the pattern using a supercritical fluid. After the development treatment or rinsing treatment, drying is carried out. In some cases, a baking treatment (post-baking) may be carried out after the development treatment. In this manner, a resist pattern can be formed.

[0323] 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.

[0324] The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB, or EUV.

[0325] The exposure method for the resist film may be a normal exposure (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography, but liquid immersion lithography is preferred. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure device is filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. The immersion medium is preferably a solvent having a refractive index greater than that of air and less 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 range. Examples of solvents having a refractive index greater than that of air and smaller than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents. As the immersion medium, water is preferably used.

[0326] An example of an alkaline developer used in the development treatment in the alkaline development process is a 0.1 to 10 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 capable of dissolving component (A) (component (A) before exposure), and may 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.

[0327] 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.

[0328] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0329] Known additives can be added to the organic developer as needed. Examples of such additives include surfactants. The surfactants are not particularly limited, but examples include ionic and nonionic fluorine-based and / or silicon-based surfactants.

[0330] 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 discharge nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0331] 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).

[0332] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method, such as a method of continuously discharging the rinse solution onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse solution for a certain period of time (dipping method), or a method of spraying the rinse solution onto the surface of the support (spray method).

[0333] 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 metal-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, and 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 (below the detection limit of the measuring device).

[0334] 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.

[0335] [Compound] The compound according to the fourth embodiment of the present invention is a compound represented by the following general formula (b-1).

[0336] [ka]

[0337] In the general formula (b-1), Ra represents an arbitrary organic group. 01 Rb is an aryl group which may have a substituent. 02 , and Rb 03 Rb each independently represents 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 is a single bond or a divalent linking group.

[0338] The compound represented by the general formula (b-1) above is the same as the component (b-1) in the resist composition according to the above-mentioned embodiment of the present invention, and the preferred examples are also the same.

[0339] The compound represented by the general formula (b-1) can be produced by a known method.

[0340] [Acid Generator] An acid generator according to a fifth embodiment of the present invention contains the compound according to the fourth embodiment described above. Such an acid generator is useful as an acid generator component for a chemically amplified resist composition. By using such an acid generator component in a chemically amplified resist composition, the environmental impact in resist pattern formation can be reduced, sensitivity can be increased, and a resist pattern with excellent lithography properties can be formed. [Example]

[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 in a predetermined molar ratio that derive the structural units constituting the polymer compounds (A)-1 to (A)-6 shown below. The obtained polymer compound was 13 The copolymer 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] [ka]

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

[0345] [ka]

[0346] Under a nitrogen atmosphere, precursor (Bpre1) (15.0 g, 36.6 mmol) and salt-exchange compound A (7.87 g, 36.6 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 (18.0 g, yield = 86.7%).

[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" by changing the precursor compound and the compound for salt exchange. NMR measurements were carried out on each of the obtained compounds, and their structures were identified from the following analytical results.

[0348] [ka]

[0349] [ka]

[0350] Table 1 shows the results of NMR measurement of compounds (B)-2 to (B)-7.

[0351] [Table 1]

[0352] [Evaluation 1 of negative resist composition] <Preparation of negative resist composition 1> (Examples 1-1 to 1-18, 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 (PEGMEA) and S-2: 225 parts by mass of propylene glycol monomethyl ether (PGME)) to prepare resist compositions for each example.

[0353] [Table 2]

[0354] [Table 3]

[0355] In Tables 2 and 3, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0356] (A)-1 to (A)-6: The above-described polymer compounds (A)-1 to (A)-6 (B)-1 to (B)-7: Acid generators each consisting of the above-mentioned compounds (B)-1 to (B)-7

[0357] (B)-11 to (B)-12: Acid generators consisting of the following comparative compounds (B)-11 to (B)-12, respectively.

[0358] [ka]

[0359] (C)-1: A crosslinking agent consisting of 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.

[0360] [ka]

[0361] <Negative resist pattern formation 1> Each resist composition was applied using a spinner to an 8-inch silicon wafer that had been treated with hexamethyldisilazane (HMDS) at 110°C for 60 seconds. The wafer was then pre-baked (PAB) on a hot plate at 90°C for 60 seconds and dried 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 (Nikon Corporation; NA (numerical aperture) = 0.60, σ = 0.68). Then, a post-exposure bake (PEB) treatment was carried out at 110° C. for 60 seconds. Next, alkaline development was carried out 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 at 23° C. for 60 seconds, followed by rinsing with pure water for 30 seconds and then shaking off and drying. 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.

[0362] [Resolution rating 1] In the above <Formation of negative resist pattern 1>, the optimum exposure dose Eop (mJ / cm) for forming an isolated space pattern with a width of 500 nm 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 (Hitachi High-Technologies Corporation). This is shown in Table 4 as "resolution (nm)."

[0363] [Depth of Focus (DOF) Evaluation 1] In the above <Formation of negative resist pattern 1>, the optimum exposure dose (Eop (mJ / cm)) for forming an isolated space pattern with a width of 500 nm is 2 )), the focal point was shifted up and down as appropriate to form an isolated space pattern in the same manner as in <Formation of Resist Pattern> above. At this time, the depth of focus (DOF, unit: nm) at which the isolated space pattern could be formed within a dimensional change rate range of the target dimension ±10% (i.e., 450 to 550 nm) was determined. This is shown as "DOF (nm)" in Table 4.

[0364] [Pattern shape evaluation 1] The cross section of the isolated space pattern having a width of 500 nm formed by the above <Formation of negative resist pattern 1> was observed using an X-SEM (accelerating voltage 15 kV, product name: SU5000, manufactured by Hitachi High-Technologies Corporation), and the isolated space pattern was evaluated according to the following criteria. The results are shown in Table 4 as "pattern shape."

[0365] <Evaluation Criteria> ◎: The pattern has high rectangularity. ◯: No undercuts were observed in the peripheral edge of the pattern that contacted the substrate, but the rectangularity of the pattern was slightly inferior to that of ⊚. ×: Undercut occurred.

[0366] [Table 4]

[0367] As shown in Table 4, it was confirmed that the resist compositions of the examples were superior to the resist compositions of the comparative examples in terms of resolution, DOF, and pattern shape.

[0368] [Evaluation of negative resist composition 2] <Preparation of negative resist composition 2> (Examples 2-1 to 2-9, Comparative Examples 2-1 to 2-4) 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 (PEGMEA) and S-2: 550 parts by mass of propylene glycol monomethyl ether (PGME)) to prepare resist compositions for each example.

[0369] [Table 5]

[0370] In Table 5, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0371] (A)-3 to (A)-4: The above-described polymer compounds (A)-3 to (A)-4 (B)-1 to (B)-7: Acid generators each consisting of the above-mentioned compounds (B)-1 to (B)-7 (B)-11 to (B)-12: Acid generators consisting of the above-mentioned comparative compounds (B)-11 to (B)-12, respectively (C)-1: A crosslinking agent comprising a compound represented by the above chemical formula (C)-1. (D)-1: An acid diffusion controller comprising a compound represented by the above chemical formula (D)-1.

[0372] <Negative resist pattern formation 2> An organic anti-reflective coating composition "DUV-42P" (trade name, manufactured by Nissan Chemical Industries, Ltd.) was applied to an 8-inch silicon wafer using a spinner, and the wafer was baked on a hot plate at 180°C for 60 seconds to dry, thereby forming an organic anti-reflective coating with a thickness of 65 nm. Each resist composition of each example was applied onto the organic anti-reflective coating using a spinner, and then dried by pre-baking (PAB) on a hot plate at 90°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 (Nikon Corporation; NA (numerical aperture) = 0.68, 2 / 3 Annular). The resist was then subjected to PEB treatment at 120° C. for 60 seconds, and then subjected to alkaline development for 60 seconds using a 2.38% by mass aqueous solution of TMAH NMD-3 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23° C. After that, 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 160 nm was formed.

[0373] [Resolution rating 2] In the above <Formation of negative resist pattern 2>, the optimum exposure dose Eop (mJ / cm) for forming an isolated space pattern with a width of 160 nm is 2 The space width (nm) of the resolved pattern was determined in the same manner as in Resolution Evaluation 1 in Evaluation 1 of the Negative Resist Composition, and this is shown in Table 6 as "Resolution (nm)".

[0374] [Depth of Focus (DOF) Evaluation 2] In the above <Formation of negative resist pattern 2>, the optimum exposure dose (Eop (mJ / cm)) for forming an isolated space pattern with a width of 160 nm is 2 )), and the focal point was shifted up and down as appropriate to form an isolated space pattern in the same manner as in <Formation of negative resist pattern 2> above. The depth of focus (DOF, unit: nm) at which the isolated space pattern could be formed within a dimensional change rate range of the target dimension ±10% (i.e., 150 to 170 nm) was determined. This is shown in Table 6 as "DOF (nm)."

[0375] [Pattern shape evaluation 2] The cross section of the isolated space pattern having a width of 160 nm formed by the above <Formation of negative resist pattern 2> was observed using an X-SEM (accelerating voltage 15 kV, product name: SU5000, manufactured by Hitachi High-Technologies Corporation), and the isolated space pattern was evaluated according to the following criteria. The results are shown in Table 6 as "pattern shape."

[0376] <Evaluation Criteria> ◎: The pattern has high rectangularity. ◯: No undercuts were observed in the peripheral edge of the pattern that contacted the substrate, but the rectangularity of the pattern was slightly inferior to that of ⊚. ×: Undercut occurred.

[0377] [Table 6]

[0378] As shown in Table 6, it was confirmed that the resist compositions of the examples were superior to the resist compositions of the comparative examples in terms of resolution, DOF, and pattern shape.

[0379] <Synthesis Examples of Polymer Compounds (A)-11 to (A)-13> Each polymer compound was synthesized using monomers in a predetermined molar ratio that derive the structural units constituting the polymer compounds (A)-11 to (A)-13 shown below. The obtained polymer compound was 13 The copolymer 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.

[0380] [ka]

[0381] [Evaluation 1 of Positive Resist Composition] <Preparation of Positive Resist Composition 1> (Examples 3-1 to 3-15, Comparative Examples 3-1 to 3-4) The components shown in Tables 7 and 8 were mixed and dissolved in a solvent (S-1: a mixed solvent of 67 parts by mass of propylene glycol monomethyl ether acetate (PEGMEA) and S-2: 67 parts by mass of propylene glycol monomethyl ether (PGME)) to prepare resist compositions for each example.

[0382] [Table 7]

[0383] [Table 8]

[0384] In Tables 7 and 8, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0385] (A)-11 to (A)-13: The above polymer compounds (A)-11 to (A)-13 (B)-1 to (B)-7: Acid generators each consisting of the above compounds (B)-1 to (B)-7 (B)-11 to (B)-12: Acid generators consisting of the above-mentioned comparative compounds (B)-11 to (B)-12, respectively (D)-1: An acid diffusion controller comprising a compound represented by the above chemical formula (D)-1.

[0386] <Positive resist pattern formation 1> Each resist composition was applied using a spinner to an 8-inch silicon wafer that had been treated with hexamethyldisilazane (HMDS) at 110°C for 60 seconds. The wafer was then pre-baked (PAB) on a hot plate at 150°C for 90 seconds and dried to form a positive resist film with a thickness of 15 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 (Nikon Corporation; NA (numerical aperture) = 0.60, σ = 0.68). Then, a post-exposure bake (PEB) treatment was carried out at 110° C. for 90 seconds. Next, alkaline development was carried out 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 at 23° C. for 60 seconds, followed by rinsing with pure water for 30 seconds and then shaking off and drying. Thereafter, post-baking was carried out at 100° C. for 60 seconds. As a result, an isolated space pattern with a width of 3 μm was formed.

[0387] [Resolution rating 3] The line size in the above <Formation of positive resist pattern 1> was observed, and the optimum exposure dose Eop (mJ / cm) at which an isolated space pattern with a width of 3 μm was formed was determined. 2 The exposure dose was 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 (Hitachi High-Technologies Corporation). This is shown in Table 9 as "resolution (μm)."

[0388] [Evaluation of Pattern Dimension Uniformity (CDU) 1] The optimum exposure dose Eop (mJ / cm) obtained by the above resolution evaluation 3 2 The entire wafer was exposed to light at 1000 kJ / cm², and the CD (space width) of the formed pattern was measured using a scanning electron microscope (S-9380, manufactured by Hitachi High-Technologies Corporation). The standard deviation (σ) calculated from the measurement results was then tripled (3σ). The results are shown in Table 9 as "CDU (nm)." The smaller the value of 3σ calculated in this way, the higher the dimensional (CD) uniformity of the multiple spaces formed in the resist film.

[0389] [Evaluation of pattern shape 3] The cross section of the isolated space pattern having a width of 3 μm formed by the above <Formation of positive resist pattern 1> was observed using an X-SEM (accelerating voltage 15 kV, product name: SU5000, manufactured by Hitachi High-Technologies Corporation), and the LS pattern was evaluated according to the following criteria. The results are shown in Table 9 as "pattern shape."

[0390] <Evaluation Criteria> ◎: The pattern has high rectangularity. ◯: No pattern tailing and good rectangularity. ×: Pattern hem pulling occurred.

[0391] [Table 9]

[0392] The results shown in Table 9 confirm that the resist compositions of the examples to which the present invention is applied can achieve high sensitivity in resist pattern formation, and can also form resist patterns with excellent lithography properties and good shapes.

[0393] [Evaluation 2 of Positive Resist Composition] <Preparation of Positive Resist Composition 2> (Examples 4-1 to 4-7, Comparative Examples 4-1 to 4-2) The components shown in Table 10 were mixed and dissolved in a solvent (S-1: a mixed solvent of 600 parts by mass of propylene glycol monomethyl ether acetate (PEGMEA) and S-2: 600 parts by mass of propylene glycol monomethyl ether (PGME)) to prepare resist compositions for each example.

[0394] [Table 10]

[0395] In Table 10, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0396] (A)-11: The above polymer compound (A-11) (B)-1 to (B)-7: Acid generators each consisting of the above compounds (B)-1 to (B)-7 (B)-11 to (B)-12: Acid generators consisting of the above-mentioned comparative compounds (B)-11 to (B)-12, respectively (D)-1: An acid diffusion controller comprising a compound represented by the above chemical formula (D)-1.

[0397] <Positive resist pattern formation 2> An organic anti-reflective coating composition "DUV-42P" (manufactured by Brewer Science) 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, forming an organic anti-reflective coating with a thickness of 65 nm. Each resist composition was applied onto the anti-reflective coating using a spinner, and then pre-baked (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. The film was selectively irradiated with a KrF excimer laser (248 nm) through a binary mask using a KrF exposure system NSR-S203B (Nikon Corporation; NA (numerical aperture) = 0.68, Sigma = 0.75), followed by PEB treatment at 110°C for 60 seconds. Next, alkaline development was performed for 60 seconds with 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 with pure water, and the film was shaken off and dried. Thereafter, post-baking was carried out at 100° C. for 60 seconds. 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.

[0398] [Resolution rating 4] The line size in the above <Formation of a 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 LS pattern was formed by gradually decreasing the exposure dose from the optimum exposure dose, and the space width (nm) of the resolved pattern was measured using a scanning electron microscope S-9380 (Hitachi High-Technologies Corporation). This is shown in Table 11 as "resolution (nm)."

[0399] [Depth of Focus (DOF) Evaluation 4] In the above <Formation of a 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 is 2 )), and shifting the focus up and down as appropriate, an LS pattern was formed in the same manner as in <Formation of Positive Resist Pattern 1> above. The depth of focus (DOF, unit: nm) within which the LS pattern could be formed within a dimensional change rate range of the target dimension ±10% (i.e., 153 to 187 nm) was determined. This is shown in Table 11 as "DOF (nm)."

[0400] [Pattern shape evaluation 4] The cross section of the LS pattern having a line width of 170 nm and a pitch of 340 nm formed by the above <Formation of a positive resist pattern 2> was observed using an X-SEM (accelerating voltage 15 kV, product name: SU5000, manufactured by Hitachi High-Technologies Corporation), and the LS pattern was evaluated according to the following criteria. The results are shown in Table 11 as "pattern shape."

[0401] <Evaluation Criteria> ◎: The pattern has high rectangularity. ◯: No pattern tailing and good rectangularity. ×: Pattern hem pulling occurred.

[0402] [Table 11]

[0403] The results shown in Table 11 confirm that the resist compositions of the examples incorporating the present invention were able to achieve high sensitivity in resist pattern formation, and were also able to form resist patterns with excellent lithography properties and good shapes.

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 composition contains a base component (A1) whose solubility in a developer changes under the action of an acid, and an acid generator component (B) that generates an acid upon exposure to light, The resist composition, wherein the acid generator component (B) contains a compound represented by the following general formula (b-1): 【Chemical 1】 In general formula (b-1), Ra represents an arbitrary organic group. ０１ Rb is an aryl group which may have a substituent. ０２ , and Rb ０３ Rb each independently represents 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 a heteroatom. ０２ and Rb ０３ may be bonded to form a ring together with the sulfur atom in the formula. ０１ is a single bond or a divalent linking group.

2. The composition comprises a base component (A2) containing an alkali-soluble resin (A2), an acid generator component (B) that generates an acid upon exposure to light, and a crosslinking agent (C), 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): The crosslinking agent (C) includes 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. Resist composition. 【Chemistry 2】 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 more. 【Chemistry 3】 In general formula (b-1), Ra represents an arbitrary organic group. ０１ Rb is an aryl group which may have a substituent. ０２ , and Rb ０３ Rb each independently represents 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 is a single bond or a divalent linking group.

3. 3. The resist composition according to claim 1, wherein the compound represented by general formula (b-1) is a compound represented by the following general formula (b-2): 【Chemistry 4】 In general formula (b-2), Ra represents an arbitrary organic group. ０１ represents an aryl group which may have a substituent. 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.

4. 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): 【Chemistry 5】 In the general formula (b-1), Ra is an arbitrary organic group. ＋ is a cation represented by the following formula (X-1) or (X-2): 【Chemistry 6】 [In the formula, Rb ０１ represents an aryl group which may have a substituent. ０１ is a group that forms an aliphatic ring together with the sulfur atom in the formula. ０１ The aliphatic ring formed by R may contain an ether bond and may have a substituent. １１ ~R １５ are each independently a hydrogen atom, a halogen atom, a hydrocarbon group which may have a substituent, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group. １１ ~R １５ Any two or more of R may be bonded to each other to form a ring. ２１ , R ２２ R are each independently a hydrogen atom, a halogen atom, a cyano group, or a hydrocarbon group which may have a substituent. ２１ and R ２２ may be bonded to each other to form a ring.

5. 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; exposing the resist film to light; and developing the resist film to form a resist pattern.

6. A compound represented by the following general formula (b-1): 【Chemistry 7】 In general formula (b-1), Ra represents an arbitrary organic group. ０１ Rb is an aryl group which may have a substituent. ０２ , and Rb ０３ Rb each independently represents 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 is a single bond or a divalent linking group.

7. An acid generator containing a compound represented by the following general formula (b-1): 【Chemistry 8】 In general formula (b-1), Ra represents an arbitrary organic group. ０１ Rb is an aryl group which may have a substituent. ０２ , and Rb ０３ Rb each independently represents 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 a heteroatom. ０２ and Rb ０３ may be bonded to form a ring together with the sulfur atom in the formula. ０１ is a single bond or a divalent linking group.

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