Resist composition and method for forming resist pattern

Abstract

The present invention provides: a resist composition which has good sensitivity in the formation of a resist pattern and is capable of reducing environmental load; and a method for forming the resist pattern. Provided is a resist composition which generates an acid upon exposure to light and is changed in the solubility in a developer solution by the action of the acid. The resist composition comprises: a resin component (A1), the solubility of which in the developer solution is changed by the action of the acid; and an acid generator component (B) which generates the acid upon exposure to light. The resin component (A1) has a constituent unit (a0) that is represented by a lactone-containing cyclic group, a -SO2-containing cyclic group, or a carbonate-containing cyclic group, and the acid generator component (B) contains a compound (B0) that has a perfluoro aromatic ring (excluding a PFAS compound).

Description

Resist composition and method for forming a resist pattern

[0001] This application claims priority to Japanese Patent Application No. 2024-085049, filed May 24, 2024, the contents of which are incorporated herein by reference.

[0002] In recent years, advances in lithography technology have led to rapid advances in the miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display devices. A common method for achieving this miniaturization is to shorten the wavelength (increase the energy) of the exposure light source.

[0003] Resist materials are required to have lithography properties such as sensitivity to these exposure light sources, resolution capable of reproducing fine-sized patterns, etc. To satisfy these requirements, a chemically amplified resist composition containing a base component whose solubility in a developer changes with the action of acid and an acid generator component that generates acid upon exposure has been used.

[0004] Chemically amplified resist compositions generally use resins having multiple structural units to improve lithography properties, etc. Furthermore, in resist pattern formation, the behavior of the acid generated from an acid generator component upon exposure is also considered to be a factor that significantly affects lithography properties. A wide variety of acid generators have been proposed for use in chemically amplified resist compositions. Known examples include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0005] In recent years, chemically amplified resist compositions have been proposed that contain a resin component having, in its structure, an acid generating group that generates acid upon exposure and an acid-decomposable group whose polarity increases due to the action of acid. For example, Patent Document 1 proposes a resist composition that contains a resin component having a structural unit that contains an anionic group at the end of its side chain.

[0006] JP 2014-152122 A

[0007] As resist patterns become finer, the formation of fine patterns of, for example, several tens of nanometers is being targeted. With such finer resist patterns, improving sensitivity has become an issue.

[0008] Furthermore, due to further increasing environmental awareness, there is a possibility that the production and use of some of the compounds (PFAS compounds) belonging to the group of perfluoroalkyl compounds and polyfluoroalkyl compounds, which are designated as restricted substances in the European REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) regulations, may be restricted.

[0009] Therefore, there is a need for the development of an acid generator that does not contain a PFAS compound. However, with a resist composition that contains an acid generator that does not contain a PFAS compound, it is difficult to obtain the sensitivity required for forming a fine resist pattern.

[0010] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a resist composition that exhibits good sensitivity when forming a resist pattern, and that also reduces the environmental impact, and a method of forming a resist pattern that uses the resist composition.

[0011] In order to solve the above problems, the present invention employs the following configuration. That is, a first aspect 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 comprising a resin component (A1) whose solubility in a developer changes due to the action of the acid, and an acid generator component (B) that generates an acid upon exposure, wherein the resin component (A1) has a structural unit (a0) represented by the following general formula (a0-m), and the acid generator component (B) includes a compound (B0) represented by the following general formula (b0):

[0012] [In the formula, Ra 0 is a lactone-containing cyclic group, —SO ２R represents at least one cyclic group selected from the group consisting of -containing cyclic groups and carbonate-containing cyclic groups. ０ represents an alkyl group having 1 to 5 carbon atoms or a hydrogen atom. 0 represents a divalent hydrocarbon group which may have an ether bond. ａ0 is an integer from 0 to 2.

[0013] [In the formula, Ar represents an aromatic ring. ０ represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. ０ represents a divalent linking group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０ represents an organic group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０ represents an organic group. n01 is an integer of 1 or more as long as the valence allows. n02 is an integer of 0 or more as long as the valence allows. When n01 is an integer of 2 or more, a plurality of Rf ０ When n02 is an integer of 2 or more, a plurality of Rb ０ may be the same or different, m is an integer of 1 or more, and M ｍ＋ represents an m-valent cation, where Rf ０ , Rb ０ , and M ｍ＋ does not include a trifluoromethyl group (except when it results in a structure represented by the following general formula (np1)) and a difluoromethylene group (except when it results in a structure represented by the following general formula (np2) or (np3)).

[0014] [In the formula, X １ Ha-OR １ , -N(R ２ ) R １ or -N(R １ ) ２ represents. ２ represents a methyl group, a monovalent aromatic hydrocarbon group which may have a substituent, -OR ３ , -SR ３ , or -NR３ R ４ represents. ３ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, a carbonyl group, -OR １ , -SR １ , -N(R ２ ) R １ or -N(R １ ) ２ Represents R １ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, or a carbonyl group. ２ , R ３ , and R ４ each independently represents a hydrogen atom, a methyl group, or a monovalent aromatic hydrocarbon group which may have a substituent.

[0015] A second aspect of the present invention is a method of forming a resist pattern, comprising the steps of forming a resist film on a support using the resist composition related to the first aspect, exposing the resist film to light, and developing the exposed resist film to form a resist pattern.

[0016] Another 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 comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; an acid generator component (B) that generates an acid upon exposure; an organic solvent component (S); and optionally a fluorine additive component (F); the base component (A) comprises a resin component (A1) that has a structural unit (a0) represented by the above general formula (a0-m); and the acid generator component (B) comprises a fluorine additive component (F) represented by the above general formula (a0-m). This resist composition contains a substance that exhibits a negative acid dissociation constant (pKa) in MSO (dimethyl sulfoxide). When the resist composition does not contain component (F), the PFAS compound exists in a ratio of 0% to less than 91% relative to all components excluding base component (A) and organic solvent component (S). When the resist composition contains component (F), the PFAS compound exists in a ratio of 0% to less than 64% relative to all components excluding base component (A) and organic solvent component (S).

[0017] According to the present invention, it is possible to provide a resist composition that exhibits good sensitivity when forming a resist pattern and that also reduces the environmental impact, and a method of forming a resist pattern that uses this resist composition.

[0018] In this specification and claims, "aliphatic" is a relative concept to aromatic, and is defined as meaning a group, compound, etc. that does not have aromaticity. "Alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups, unless otherwise specified. The same applies to alkyl groups in alkoxy groups. "Alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups, unless otherwise specified. "Halogen atom" includes fluorine, chlorine, bromine, and iodine atoms. "Structural unit" means a monomer unit that constitutes a polymer compound (resin, polymer, copolymer). When describing "may have a substituent," it refers to cases where a hydrogen atom (-H) is replaced with a monovalent group, and cases where a methylene group (-CH ２ The term "exposure" encompasses both cases where the radical (-) is substituted with a divalent group.

[0019] An "acid-decomposable group" is a group having acid decomposability in which at least a part of the bond 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 by the action of an acid include groups that decompose by the action of an acid to generate a polar group. Examples of polar groups include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO ３ More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, groups in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0020] The term "acid-dissociable group" refers to either (i) a group having acid dissociability in which the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group in which a portion of the bond is cleaved by the action of an acid, followed by a decarboxylation reaction, in which the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved. 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 is dissociated by the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, thereby increasing the polarity. As a result, the polarity of the entire component (A1) 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.

[0021] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly classified into non-polymers and polymers. As non-polymers, those with a molecular weight of 500 or more and less than 4000 are usually used (hereinafter referred to as "low molecular weight compounds"). Hereinafter, when referring to "resin," "high molecular weight compound," or "polymer," it refers to a polymer with a molecular weight of 1000 or more. The molecular weight of the polymer is the weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).

[0022] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. In the "acrylic acid ester", the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent (R αｘ ) is an atom or group other than a hydrogen atom. αｘ ) is substituted with a substituent containing an ester bond, or αｘThis 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 acrylic acid is bonded. Hereinafter, acrylic esters in which the hydrogen atom bonded to the α-position carbon atom has been replaced with a substituent may be referred to as α-substituted acrylic esters.

[0023] The term "derivative" is used to refer to a compound in which the hydrogen atom at the α-position of the target compound has been substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include a compound in which the hydrogen atom of the hydroxyl group of a target compound in which the hydrogen atom at the α-position may be substituted with a substituent has been substituted with an organic group; a compound in which the hydrogen atom at the α-position of the target compound may be substituted with a substituent to which a substituent other than a hydroxyl group is bonded; and the like. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. Examples of substituents that can be used to replace the hydrogen atom at the α-position of hydroxystyrene include R αｘ The same can be mentioned.

[0024] The term "PFAS compound" refers to a group of compounds that belong to the group of perfluoroalkyl compounds and polyfluoroalkyl compounds, and specifically refers to a compound that contains at least one of a trifluoromethyl group (excluding cases where the structure is represented by the above general formula (np1)) and a difluoromethylene group (excluding cases where the structure is represented by the above general formula (np2) or (np3)).

[0025] In this specification and claims, some structures represented by chemical formulas may have asymmetric carbon atoms, and may exist as enantiomers or diastereoisomers. In such cases, a single chemical formula represents all of the isomers. These isomers may be used alone or as a mixture.

[0026] (Resist Composition) The resist composition of this embodiment generates an acid upon exposure, and its solubility in a developer changes due to the action of the acid. This resist composition contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of an acid, and an acid generator component (B) (hereinafter also referred to as "component (B)") that generates an acid upon exposure. The component (A) contains a resin component (component (A1)) having a structural unit (a0) described below. In the resist composition of this embodiment, this component (A1) may generate an acid upon exposure, or may trap the acid generated upon exposure (i.e., control the diffusion of the acid). The component (B) contains a compound (B0) described below. Because compound (B0) does not contain a PFAS compound, the resist composition of this embodiment reduces the environmental impact.

[0027] Furthermore, among the resist compositions of this embodiment, resist compositions according to other aspects include a substance in component (B) that exhibits a negative pKa value in DMSO, and by setting the PFAS compound abundance ratio within a specific range, environmental impact can be reduced. Preferably, component (B) includes compound (B0), which will be described later. When the resist composition according to other aspects does not contain component (F), the PFAS compound abundance ratio relative to all components other than base component (A) and organic solvent component (S) in the resist composition (hereinafter also referred to as the "PFAS compound abundance ratio") is 0% to less than 91%, preferably 0% to less than 64%, and more preferably 0% to 35% or less. When component (F) is contained, the PFAS compound abundance ratio is 0% to less than 64%, preferably 0% to 35% or less, and more preferably 0% to 26% or less. The PFAS compound abundance ratio can be calculated using the method described in the Examples section below.

[0028]

[0043] When a resist film is formed using the resist composition of this embodiment and then subjected to selective exposure, an acid is generated from the component (B) in the exposed areas of the resist film, and the solubility of the component (A) in a developer changes due to the action of the acid, whereas the solubility of the component (A) 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. Therefore, when the resist film is developed, if the resist composition is positive, the exposed areas of the resist film are dissolved and removed, forming a positive resist pattern, whereas if the resist composition is negative, the unexposed areas of the resist film are dissolved and removed, forming a negative resist pattern.

[0029] In this specification, a resist composition that dissolves and removes exposed portions of a resist film to form a positive resist pattern is referred to as a positive resist composition, and a resist composition that dissolves and removes unexposed portions of a resist film to form a negative resist pattern is referred to as a negative resist composition. The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Furthermore, the resist composition of this embodiment may be for use in an alkaline development process in which an alkaline developer is used for the development treatment during resist pattern formation, or for use in a solvent development process in which a developer containing an organic solvent (organic developer) is used for the development treatment.

[0030] <Component (A)> In the resist composition of this embodiment, the component (A) contains a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes under the action of an acid. By using the component (A1), the polarity of the base component changes before and after exposure, making it possible to obtain good development contrast not only in an alkaline development process but also in a solvent development process. As the component (A), at least the component (A1) is used, and other polymeric compounds and / or low molecular weight compounds may be used in combination with the component (A1). From the perspective of reducing the environmental impact, it is preferable that the component (A) does not contain a PFAS compound.

[0031] When an alkaline development process is applied, the base component containing the component (A1) is poorly soluble in an alkaline developer before exposure, and when, for example, an acid is generated from the component (B) upon exposure, the polarity of the base component increases due to the action of the acid, thereby increasing its solubility in an alkaline developer. Therefore, in forming a resist pattern, when a resist film obtained by applying the resist composition to a support is selectively exposed, the exposed areas of the resist film change from being poorly soluble in an alkaline developer to being soluble, while the unexposed areas of the resist film remain poorly soluble in alkali, and therefore a positive resist pattern is formed by alkaline development.

[0032] On the other hand, when a solvent development process is applied, the base component containing the component (A1) is highly soluble in an organic developer before exposure, but when an acid is generated from the component (B) upon exposure, for example, the polarity increases due to the action of the acid, and the solubility in the organic developer decreases. Therefore, in forming a resist pattern, when a resist film obtained by applying the resist composition to a support is selectively exposed, the exposed areas of the resist film change from soluble to poorly soluble in an organic developer, while the unexposed areas of the resist film remain soluble. Therefore, by developing with an organic developer, a contrast can be created between the exposed and unexposed areas, and a negative resist pattern can be formed.

[0033] In the resist composition of this embodiment, as the component (A), one type of compound may be used, or two or more types may be used in combination.

[0034] Regarding the Component (A1): The component (A1) is a resin component whose solubility in a developer changes under the action of an acid, and includes a structural unit (a0) represented by the general formula (a0-m) described below. In addition to the structural unit (a0), the component (A1) may also include other structural units as necessary.

[0035] <Structural Unit (a0)> The structural unit (a0) is a structural unit represented by the following general formula (a0-m).

[0036] [In the formula, Ra 0 is a lactone-containing cyclic group, —SO ２R represents at least one cyclic group selected from the group consisting of -containing cyclic groups and carbonate-containing cyclic groups. ０ represents an alkyl group having 1 to 5 carbon atoms or a hydrogen atom. 0 represents a divalent hydrocarbon group which may have an ether bond. ａ0 is an integer from 0 to 2.

[0037] In the formula (a0-m), Ra 0 the lactone-containing cyclic group, —SO ２ When the component (A1) is used to form a resist film, the -containing cyclic group or carbonate-containing cyclic group has effects such as appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development, thereby resulting in improved lithography properties.

[0038] In this specification, the term "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, and when there is further ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. In the formula (a0-m), Ra 0 The lactone-containing cyclic group in is not particularly limited and any group can be used. Specific examples include groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0039] [In the formula, Ra' ２１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group, or a cyano group; R″ is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or —SO ２ A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, n' is an integer of 0 to 2, and m' is 0 or 1. * represents a bond.

[0040] In the general formulas (a2-r-1) to (a2-r-7), Ra' ２１ The alkyl group in Ra' is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Of these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. ２１ The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, ２１ Examples of the alkyl groups include those mentioned as examples of the alkyl group in the above formula and an oxygen atom (—O—). ２１ The halogen atom in Ra' is preferably a fluorine atom. ２１ As the halogenated alkyl group in the formula Ra′, ２１ Examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0041] Ra' ２１ In the formula, -COOR" and -OC(=O)R", R" each represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO ２-containing cyclic group. The alkyl group for R" may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R" is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably has 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably has 4 to 12 carbon atoms, and most preferably has 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; groups in which one or more hydrogen atoms have been removed from a polycycloalkane, such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane; more specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane, such as cyclopentane or cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ]decane, tetracyclododecane, and other polycycloalkanes in which one or more hydrogen atoms have been removed. Examples of the lactone-containing cyclic group in R" include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) above. Examples of the carbonate-containing cyclic group in R" are the same as the carbonate-containing cyclic groups described below, and specific examples include the groups represented by the general formulae (ax3-r-1) to (ax3-r-3). -SO in R" ２ The -containing cyclic group includes the -SO group described below. ２ Ra' is the same as the -containing cyclic group, and specific examples thereof include groups represented by general formulae (a5-r-1) to (a5-r-4). ２１ The hydroxyalkyl group in the formula (Ra') preferably has 1 to 6 carbon atoms. ２１ and a group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0042] Ra' ２１ Among the above, each of the groups is preferably independently a hydrogen atom or a cyano group.

[0043] In the general formulae (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms for A" is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between carbon atoms of the alkylene group, such as O-CH ２ -, -CH ２ -O-CH ２ -, -S-CH ２ -, -CH ２ -S-CH ２ A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0044] Specific examples of the groups represented by the general formulae (a2-r-1) to (a2-r-7) are listed below.

[0045]

[0046]

[0047] "-SO ２ -containing cyclic group" means a group having a -SO ２ represents a cyclic group containing a ring containing -, specifically, -SO ２ The sulfur atom (S) in - forms a part of the ring skeleton of the cyclic group. ２ The ring containing - is counted as the first ring, and when there is only this ring, it is called a monocyclic group, and when there is further ring structure, it is called a polycyclic group regardless of the structure. ２ The -containing cyclic group may be a monocyclic group or a polycyclic group. ２ The -containing cyclic group is particularly one that does not contain an -O-SO group in its ring skeleton. ２ Cyclic groups containing -, i.e., -O-SO ２ It is preferred that the —O—S— in — is a cyclic group containing a sultone ring forming part of the ring skeleton.２ More specific examples of the -containing cyclic group include groups represented by the following general formulae (a5-r-1) to (a5-r-4).

[0048] [In the formula, Ra' ５１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group, or a cyano group; R″ is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or —SO ２ A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer of 0 to 2. * represents a bond.

[0049] In the general formulae (a5-r-1) and (a5-r-2), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3), and (a2-r-5). ５１ The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR″, —OC(═O)R″, and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each selected from the group consisting of Ra′ ２１ Specific examples of the groups represented by general formulae (a5-r-1) to (a5-r-4) are listed below. In the formulae, "Ac" represents an acetyl group.

[0050]

[0051]

[0052]

[0053] The term "carbonate-containing cyclic group" refers to a cyclic group containing a ring (carbonate ring) containing -O-C(=O)-O- in its ring skeleton. The carbonate ring is counted as the first ring, and when there is only a carbonate ring, it is called a monocyclic group, and when there is furthermore another ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. There are no particular limitations on the carbonate-containing cyclic group, and any group can be used. Specific examples include groups represented by the following general formulae (ax3-r-1) to (ax3-r-3), respectively.

[0054] [In the formula, Ra' ｘ３１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group, or a cyano group; R″ is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or —SO ２ A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, or an oxygen atom or a sulfur atom, p' is an integer of 0 to 3, and q' is 0 or 1. * represents a bond.

[0055] In the general formulae (ax3-r-2) to (ax3-r-3), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3) and (a2-r-5). ３１ The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR″, —OC(═O)R″, and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each selected from the group consisting of Ra′ ２１ Specific examples of the groups represented by general formulae (ax3-r-1) to (ax3-r-3) are listed below.

[0056]

[0057] In the formula (a0-m), Ra 0 the lactone-containing cyclic group, —SO ２Preferred examples of the -containing cyclic group and carbonate-containing cyclic group include the groups represented by the above general formulae (a2-r-1) to (a2-r-7), (a5-r-1) to (a5-r-4), and (ax3-r-1) to (ax3-r-3). Among these, lactone-containing cyclic groups and -SO ２ -containing cyclic groups are preferred, groups represented by the above general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r-1) are more preferred, and groups represented by the above general formula (a2-r-2) or (a5-r-1) are even more preferred. Specifically, any of the groups represented by the above chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1), (r-sl-1-1), and (r-sl-1-18) are preferred, any of the groups represented by the above chemical formulas (r-lc-2-1) to (r-lc-2-18), and (r-sl-1-1) are more preferred, and any of the groups represented by the above chemical formulas (r-lc-2-1), (r-lc-2-12), and (r-sl-1-1) are even more preferred.

[0058] In the formula (a0-m), R ０ The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. ０ As the alkyl group, a hydrogen atom or a methyl group is most preferred in view of industrial availability.

[0059] In the formula (a0-m), Va ０ The divalent hydrocarbon group which may have an ether bond in the formula (I) may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0060] Va ０The aliphatic hydrocarbon group as the divalent hydrocarbon group optionally having an ether bond in (1) may be saturated or unsaturated, and is usually preferably saturated. More specific examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0061] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0062] Examples of the aliphatic hydrocarbon group containing a ring in its structure include alicyclic hydrocarbon groups (groups in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. A preferred monocyclic alicyclic hydrocarbon group is a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ]decane, tetracyclododecane, and the like.

[0063] Va ０The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (an arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (an aryl group) has been substituted with an alkylene group (for example, a group in which one further hydrogen atom has been removed from the aryl group of 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 or 2, and particularly preferably 1.

[0064] In the formula (a0-m), n ａ0 is not particularly limited, but is preferably 0 or 1.

[0065] Specific examples of the structural unit (a0) are shown below, but are not limited to these.

[0066]

[0067] From the viewpoint of achieving both high sensitivity and reduced environmental impact, the structural unit (a0) is preferably one selected from the group consisting of structural units represented by the above formulas (a0-m-1) to (a0-m-5).

[0068] The structural unit (a0) contained in the component (A1) may be of one type, or may be of two or more types.

[0069] Within the component (A1), the proportion of the structural unit (a0) relative to the total (100 mol %) of all structural units constituting the component (A1) is preferably within a range from 5 to 80 mol %, more preferably from 10 to 75 mol %, even more preferably from 30 to 70 mol %, and particularly preferably from 40 to 60 mol %.

[0070] <<Other Structural Units>> The component (A1) preferably has the structural unit (a1) described below in addition to the structural unit (a0) described above. Furthermore, the component (A1) may have other structural units as needed in addition to the structural unit (a0) described above. Examples of other structural units include a structural unit (a3) ​​containing a polar group-containing aliphatic hydrocarbon group; a structural unit (a4) containing an acid-non-dissociable aliphatic cyclic group; a structural unit (st) derived from styrene or a styrene derivative; and a structural unit derived from hydroxystyrene or a hydroxystyrene derivative.

[0071] <<Structural Unit (a1)>> The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases when acted upon by an acid.

[0072] Examples of the acid-dissociable group include those that have been proposed as acid-dissociable groups for base resins of chemically amplified resist compositions. Specific examples of acid-dissociable groups that have been proposed as acid-dissociable groups for base resins of chemically amplified resist compositions include the "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "tertiary alkyloxycarbonyl acid-dissociable groups" described below.

[0073] 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 general formula (a1-r-1) (hereinafter, sometimes referred to as "acetal-type acid-dissociable group"):

[0074] [In the formula, Ra' １ , Ra' ２ is a hydrogen atom or an alkyl group. ３ is a hydrocarbon group, and Ra' ３ is Ra' １ , Ra'２ may be bonded to any one of the following to form a ring.]

[0075] In formula (a1-r-1), Ra' １ and Ra' ２ Among Ra', at least one is preferably a hydrogen atom, and more preferably both are hydrogen atoms. １ or Ra' ２ When is an alkyl group, examples of the alkyl group include the same alkyl groups as those exemplified as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester above, and alkyl groups having 1 to 5 carbon atoms are preferred. Specific examples include linear or branched alkyl groups. More specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. A methyl group or an ethyl group is more preferred, and a methyl group is particularly preferred.

[0076] 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, and an n-pentyl group. Of these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0077] 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.

[0078] Ra' ３When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As an aliphatic hydrocarbon group that is a monocyclic group, a group in which one hydrogen atom has been removed from a monocycloalkane is preferred. As the monocycloalkane, one having 3 to 6 carbon atoms is preferred, and specific examples thereof include cyclopentane and cyclohexane. As an aliphatic hydrocarbon group that is a polycyclic group, a group in which one hydrogen atom has been removed from a polycycloalkane is preferred, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferred, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ]decane, tetracyclododecane, and the like.

[0079] Ra' ３ When the cyclic hydrocarbon group described above becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Ra' ３Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (an aryl group or a heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 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 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0080] Ra' ３ The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R Ｐ１ , -R Ｐ２ -O-R Ｐ１ , -R Ｐ２ -CO-R Ｐ１ , -R Ｐ２ -CO-OR Ｐ１ , -R Ｐ２ -O-CO-R Ｐ１ , -R Ｐ２ -OH, -R Ｐ２ -CN or -R Ｐ２ -COOH (hereinafter, these substituents are collectively referred to as "Ra ｘ５ ") etc. Here, R Ｐ１ is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Ｐ２ is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Ｐ１ and R Ｐ２Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group, and the aromatic hydrocarbon group may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of one type of the above-mentioned substituents, or may have one or more of each of two or more types of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.0]octanyl group, and the like. ２，６ ]decanyl group, tricyclo[3.3.1.1 ３，７ ] decanyl group, tetracyclo[6.2.1.1 ３，６ .0 ２，７ Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0081] Ra' ３ But Ra' １ , Ra' ２ When the cyclic group is bonded to any one of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0082] Tertiary alkyl ester acid-dissociable group: Among the above polar groups, examples of the acid-dissociable group protecting the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2): Of the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group will hereinafter be referred to as "tertiary alkyl ester acid-dissociable groups" for convenience.

[0083] [In the formula, Ra' ４ ~Ra' ６ are each a hydrocarbon group, and Ra' ５ , Ra' ６ may be bonded to each other to form a ring.

[0084] Ra' ４ Examples of the hydrocarbon group of Ra' include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. ４ The linear or branched alkyl group and the cyclic hydrocarbon group (a monocyclic aliphatic hydrocarbon group, a polycyclic aliphatic hydrocarbon group, and an aromatic hydrocarbon group) in ３ The same as Ra' can be mentioned. ４ The chain or cyclic alkenyl group in Ra' is preferably an alkenyl group having 2 to 10 carbon atoms. ５ , Ra' ６ The hydrocarbon group of Ra' ３ The same can be mentioned.

[0085] Ra' ５ and Ra' ６ When Ra' is bonded to each other to form a ring, preferred examples thereof include a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2), and a group represented by the following general formula (a1-r2-3). ４ ~Ra' ６ When the groups are not bonded to each other and are independent hydrocarbon groups, preferred examples include groups represented by the following general formula (a1-r2-4).

[0086] [In formula (a1-r2-1), Ra' １０ represents a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group. １１ is Ra' １０represents a group which forms an aliphatic cyclic group together with the carbon atom to which it is bonded. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group which forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra １０１ ~Ra １０３ are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. １０１ ~Ra １０３ Two or more of the above may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ In formula (a1-r2-4), Ra′ is an aromatic hydrocarbon group which may have a substituent. １２ and Ra' １３ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms of this chain saturated hydrocarbon group may be substituted. １４ represents a hydrocarbon group which may have a substituent. * represents a bond.]

[0087] In the above formula (a1-r2-1), Ra' １０ is a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group.

[0088] Ra' １０ The linear alkyl group in Ra' has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. １０ In the formula (I), the branched alkyl group is the above-mentioned Ra' ３ The same can be mentioned.

[0089] Ra' １０In the above, the alkyl group may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Furthermore, some of the carbon atoms (such as methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -S-, and -S(=O) ２ -, -S(=O) ２ -O- and the like.

[0090] In formula (a1-r2-1), Ra' １１ (Ra' １０ The aliphatic cyclic group formed together with the carbon atom to which Ra' is bonded in formula (a1-r-1) is ３ Among these, a monocyclic alicyclic hydrocarbon group is preferred, and specifically, a cyclopentyl group or a cyclohexyl group is more preferred, with a cyclopentyl group being even more preferred.

[0091] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the formula (a1-r-1). ３ Examples of the cyclic hydrocarbon group include a group in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in the formula (I). The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of the substituent include the above-mentioned Ra' ３ In formula (a1-r2-2), the substituents that the cyclic hydrocarbon group in formula (a1-r2-2) may have are the same as those in formula (a1-r2-2). １０１ ~Ra １０３ In the formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. １０１ ~Ra １０３In the above formula, examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, and cyclododecyl group; ２，６ ]decanyl group, tricyclo[3.3.1.1 ３，７ ] decanyl group, tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] and polycyclic aliphatic saturated hydrocarbon groups such as a dodecanyl group and an adamantyl group. １０１ ~Ra １０３ Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom is particularly preferable.

[0092] The above Ra １０１ ~Ra １０３ Examples of the substituents that the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the formula (I) include the above-mentioned Ra ｘ５ The same groups as those shown below can be mentioned.

[0093] 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.

[0094] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). ３ In formula (a1-r2-3), the groups exemplified as the aliphatic hydrocarbon group are preferably monocyclic or polycyclic groups. １０４Examples of the aromatic hydrocarbon group in the formula (I) include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. １０４ is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0095] Ra in formula (a1-r2-3) １０４ Examples of the substituent that may be possessed by the group include a methyl group, an ethyl group, a propyl group, a hydroxy group, a carboxy group, a halogen atom, an alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group), an alkyloxycarbonyl group, and the like.

[0096] In formula (a1-r2-4), Ra' １２ and Ra' １３ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. １２ and Ra' １３ In the formula (I), the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned Ra １０１ ~Ra １０３ The monovalent saturated chain hydrocarbon group having 1 to 10 carbon atoms in the formula (1) may be substituted in part or in whole. １２ and Ra' １３ Among these, Ra' is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group. １２ and Ra' １３ In the case where the chain saturated hydrocarbon group represented by the formula: ｘ５ The same groups as those shown below can be mentioned.

[0097] In formula (a1-r2-4), Ra' １４is 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.

[0098] Ra' １４ The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Of these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0099] Ra' １４ The branched alkyl group in the formula (I) preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0100] 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. As an aliphatic hydrocarbon group that is a monocyclic group, a group in which one hydrogen atom has been removed from a monocycloalkane is preferred. As the monocycloalkane, one having 3 to 6 carbon atoms is preferred, and specific examples thereof include cyclopentane and cyclohexane. As an aliphatic hydrocarbon group that is a polycyclic group, a group in which one hydrogen atom has been removed from a polycycloalkane is preferred, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferred, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ]decane, tetracyclododecane, and the like.

[0101] Ra' １４ As the aromatic hydrocarbon group in １０４ Among them, the aromatic hydrocarbon groups Ra' are the same as those in １４is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. １４ Examples of the substituent that may be possessed by Ra include １０４ Examples of the substituents include the same as those that may be possessed by the group.

[0102] Ra' in formula (a1-r2-4) １４ When Ra' in formula (a1-r2-4) is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. １４ When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be any one of the 1st, 2nd, and 9th positions of the anthryl group.

[0103] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0104]

[0105]

[0106]

[0107] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0108]

[0109]

[0110]

[0111] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0112]

[0113] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0114]

[0115] Tertiary alkyloxycarbonyl acid dissociable group: Examples of the acid dissociable group that protects the hydroxyl group of the polar group include acid dissociable groups represented by the following general formula (a1-r-3) (hereinafter, for convenience, may be referred to as "tertiary alkyloxycarbonyl acid dissociable group").

[0116] [In the formula, Ra' ７ ~Ra' ９ are each an alkyl group.

[0117] In formula (a1-r-3), Ra' ７ ~Ra' ９ are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 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 to 4.

[0118] Examples of the structural unit (a1) include a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, a structural unit derived from acrylamide, a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least some of the hydrogen atoms in the hydroxyl groups are protected with a substituent containing the above-mentioned acid-decomposable group, and a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative in which at least some of the hydrogen atoms in -C(═O)-OH are protected with a substituent containing the above-mentioned acid-decomposable group.

[0119] Of the above, the structural unit (a1) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. Preferred specific examples of such structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2):

[0120] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. １ is a divalent hydrocarbon group which may have an ether bond. ａ１ is an integer from 0 to 2. １ is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-2). １ is n ａ２ is a monovalent hydrocarbon group, n ａ２ is an integer from 1 to 3, and Ra ２ is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0121] In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. A fluorine atom is particularly preferred as the halogen atom. 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 viewpoints of industrial availability and reducing the burden on the environment, a hydrogen atom or a methyl group is most preferred.

[0122] In the formula (a1-1), Va １ The divalent hydrocarbon group in the general formula (a0-m) may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. ０ The divalent hydrocarbon groups are the same as those in the above.

[0123] In the formula (a1-1), Ra １ is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0124] In the formula (a1-2), Wa １ n in ａ２The +1-valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, but is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in the structure, and groups combining linear or branched aliphatic hydrocarbon groups with aliphatic hydrocarbon groups containing a ring in the structure. ａ２ The +1 valence is preferably 2 to 4, more preferably 2 or 3.

[0125] In the formula (a1-2), Ra ２ is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0126] Specific examples of the structural unit represented by formula (a1-1) are shown below. In each of the following formulas, R α represents a hydrogen atom or a methyl group.

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135] The structural unit (a1) contained in the component (A1) may be of one type, or may consist of two or more types. As the structural unit (a1), a structural unit represented by the above formula (a1-1) is more preferable. Among these, as the structural unit (a1), one containing a structural unit represented by the following general formula (a1-1-1) is particularly preferable.

[0136] [In the formula, Ra １" is an acid-dissociable group represented by general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4).

[0137] In the formula (a1-1-1), R, Va １ and n ａ１ represents R, Va in the formula (a1-1). １ and n ａ１ The acid-dissociable group represented by general formula (a1-r2-1), (a1-r2-3), or (a1-r2-4) is as described above. Among these, it is preferable to select an acid-dissociable group that is a cyclic group.

[0138] In the formula (a1-1-1), Ra １ Among the above, " is preferably an acid-dissociable group represented by general formula (a1-r2-1).

[0139] The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol %, more preferably 10 to 75 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 60 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a1) is at least the lower limit of the above-mentioned preferred range, lithography properties such as sensitivity, resolution, and roughness improvement are improved. On the other hand, by ensuring that the proportion is at most the upper limit of the above-mentioned preferred range, a balance with other structural units can be achieved, resulting in various favorable lithography properties.

[0140] Regarding the structural unit (a3): In addition to the structural unit (a0), the component (A1) may further include a structural unit (a3) ​​(excluding those corresponding to the structural unit (a0) or the structural unit (a1)) that includes a polar group-containing aliphatic hydrocarbon group. When the component (A1) includes the structural unit (a3), the hydrophilicity of the component (A) is enhanced, contributing to improved resolution. Furthermore, the acid diffusion length can be appropriately adjusted.

[0141] Examples of polar groups include hydroxyl groups, cyano groups, carboxy groups, and hydroxyalkyl groups in which some of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms, with hydroxyl groups being particularly preferred. Examples of aliphatic hydrocarbon groups include linear or branched hydrocarbon groups (preferably alkylene groups) having 1 to 10 carbon atoms, and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be either a monocyclic group or a polycyclic group, and can be appropriately selected from the many groups proposed for use in resins for ArF excimer laser resist compositions, for example.

[0142] When the cyclic group is a monocyclic group, it more preferably has 3 to 10 carbon atoms. Among these, structural units derived from acrylate esters containing an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the alkyl group's hydrogen atoms are substituted with fluorine atoms are more preferred. Examples of such monocyclic groups include groups in which two or more hydrogen atoms have been removed from a monocycloalkane. Specific examples include groups in which two or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane, cyclohexane, or cyclooctane. Of these monocyclic groups, groups in which two or more hydrogen atoms have been removed from cyclopentane and groups in which two or more hydrogen atoms have been removed from cyclohexane are industrially preferred.

[0143] When the cyclic group is a polycyclic group, the polycyclic group more preferably has 7 to 30 carbon atoms. Among them, structural units derived from acrylate esters containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms are more preferred. Examples of such polycyclic groups include groups in which two or more hydrogen atoms have been removed from bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc. Specific examples include adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６]decane, tetracyclododecane, and other polycycloalkanes by removing two or more hydrogen atoms. Among these polycyclic groups, groups by removing two or more hydrogen atoms from adamantane, groups by removing two or more hydrogen atoms from norbornane, and groups by removing two or more hydrogen atoms from tetracyclododecane are industrially preferred.

[0144] The structural unit (a3) ​​is not particularly limited, and any structural unit can be used as long as it contains a polar group-containing aliphatic hydrocarbon group. The structural unit (a3) ​​is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and which contains a polar group-containing aliphatic hydrocarbon group. When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the structural unit (a3) ​​is preferably a structural unit derived from a hydroxyethyl ester of acrylic acid. Furthermore, when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, preferred structural units for the structural unit (a3) ​​include structural units represented by the following formulas (a3-1), (a3-2), and (a3-3); when the hydrocarbon group is a monocyclic group, preferred structural units include structural units represented by formula (a3-4).

[0145] [In the formula, R is the same as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, l is an integer of 0 to 5, and s is an integer of 1 to 3.]

[0146] In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, the hydroxyl group is preferably bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, the hydroxyl group is preferably bonded to the 3rd position of the adamantyl group. j is preferably 1, and the hydroxyl group is particularly preferably bonded to the 3rd position of the adamantyl group.

[0147] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

[0148] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxyl group of the acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5- or 6-position of the norbornyl group.

[0149] In formula (a3-4), t' is preferably 1 or 2. l is preferably 0 or 1. s is preferably 1. The fluorinated alkyl alcohol is preferably bonded to the 3- or 5-position of the cyclohexyl group.

[0150] The structural unit (a3) ​​contained in the component (A1) may be one type, or two or more types. When the component (A1) contains the structural unit (a3), the proportion of the structural unit (a3) ​​is preferably 1 to 30 mol %, more preferably 2 to 25 mol %, and even more preferably 5 to 20 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a3) ​​is at least the preferred lower limit, the effects achieved by including the structural unit (a3) ​​can be fully obtained due to the effects described above. By ensuring that the proportion is at most the preferred upper limit, a balance with the other structural units can be achieved, resulting in various favorable lithography properties.

[0151] Regarding the structural unit (a4): In addition to the structural unit (a0), the component (A1) may further include a structural unit (a4) that includes an acid-non-dissociable aliphatic cyclic group. When the component (A1) includes the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Furthermore, the hydrophobicity of the component (A) is enhanced. Improved hydrophobicity contributes to improvements in resolution, resist pattern shape, and the like, particularly in solvent development processes. The "acid-non-dissociable cyclic group" within the structural unit (a4) is a cyclic group that, when acid is generated in the resist composition upon exposure (for example, when acid is generated from a structural unit that generates acid upon exposure or from the component (B)), remains intact within the structural unit without dissociating even when acted upon by the acid.

[0152] Preferred examples of the structural unit (a4) include structural units derived from acrylate esters containing an acid-non-dissociable aliphatic cyclic group. The cyclic group can be any of the numerous groups conventionally known for use in resin components of resist compositions for ArF excimer lasers, KrF excimer lasers (preferably ArF excimer lasers), and the like. In terms of industrial availability, the cyclic group is preferably at least one selected from the group consisting of a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent. Specific examples of the structural unit (a4) include structural units represented by the following general formulas (a4-1) to (a4-7):

[0153] [In the formula, R α is the same as above.]

[0154] The structural unit (a4) contained in the component (A1) may be of one type, or may be of two or more types. When the component (A1) contains the structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 40 mol %, and more preferably 5 to 20 mol %, relative to the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a4) is at least as high as the preferred lower limit, the effects of including the structural unit (a4) can be fully obtained, while by ensuring that the proportion is at most as high as the preferred upper limit, it is easier to achieve a balance with the other structural units.

[0155] The resist composition may contain one type of component (A1), or two or more types may be used in combination. In the resist composition of this embodiment, the component (A1) is a polymeric compound having a repeating structure of the structural unit (a0), and preferably includes a polymeric compound having a repeating structure of the structural unit (a0) and the structural unit (a1). Among the above, preferred examples of the component (A1) include a polymeric compound consisting of a repeating structure of the structural unit (a0) and the structural unit (a1); and a polymeric compound consisting of a repeating structure of the structural unit (a0), the structural unit (a1), and the structural unit (a3).

[0156] In polymeric compounds having a repeating structure of the structural unit (a0) and the structural unit (a1), the proportion of the structural unit (a0) relative to the total (100 mol%) of all structural units constituting the polymeric compound is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%. Furthermore, the proportion of the structural unit (a1) in the polymeric compound relative to the total (100 mol%) of all structural units constituting the polymeric compound is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%.

[0157] In polymeric compounds having a repeating structure of the structural unit (a0), the structural unit (a1), and the structural unit (a3), the proportion of the structural unit (a0) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%, relative to the total (100 mol%) of all structural units constituting the polymeric compound. Furthermore, the proportion of the structural unit (a1) in the polymeric compound is preferably 10 to 70 mol%, and even more preferably 20 to 60 mol%, relative to the total (100 mol%) of all structural units constituting the polymeric compound. Furthermore, the proportion of the structural unit (a3) ​​in the polymeric compound is preferably 1 to 30 mol%, more preferably 5 to 25 mol%, even more preferably 5 to 20 mol%, and particularly preferably 5 to 15 mol%, relative to the total (100 mol%) of all structural units constituting the polymeric compound.

[0158] Within the polymer compound, the molar ratio of the structural unit (a0) to the structural unit (a1) (structural unit (a0):structural unit (a1)) is preferably within a range from 2:8 to 8:2, more preferably from 3:7 to 7:3, and even more preferably from 4:6 to 6:4.

[0159] The component (A1) can be produced by dissolving the monomers that derive each structural unit in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the solution and polymerizing the resulting solution. Alternatively, the component (A1) can be produced by dissolving a monomer that derives the structural unit (a0) and, if necessary, a monomer that derives a structural unit other than the structural unit (a0) (e.g., the structural unit (a1)) in a polymerization solvent, and then adding the above-mentioned radical polymerization initiator to the solution and polymerizing the resulting solution.

[0160] The weight-average molecular weight (Mw) of component (A1) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. When the Mw of component (A1) is equal to or less than the preferred upper limit of this range, the component has sufficient solubility in a resist solvent for use as a resist, while when the Mw is equal to or greater than the preferred lower limit of this range, the component exhibits good dry etching resistance and resist pattern cross-sectional shape. The dispersity (Mw / Mn) of component (A1) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Here, Mn represents the number-average molecular weight.

[0161] Regarding the component (A2): The resist composition of this embodiment may also use, as the component (A), a base component (A2) (hereafter referred to as "component (A2)") that does not fall under the category of the component (A1) and whose solubility in a developer changes under the action of acid. There are no particular limitations on the component (A2), and it may be arbitrarily selected from the many base components conventionally known for use in chemically amplified resist compositions. The component (A2) may be a polymeric compound or a low molecular weight compound, and may be used either alone or in combination of two or more types.

[0162] The proportion of the component (A1) in the component (A), relative to the total mass of the component (A), is preferably 25 mass% or more, more preferably 50 mass% or more, and even more preferably 75 mass% or more, and may even be 100 mass%. When this proportion is 25 mass% or more, a resist pattern that is excellent in various lithography properties, such as high sensitivity, resolution, and improved roughness, is more likely to be formed.

[0163] The amount of the component (A) in the resist composition of this embodiment may be adjusted depending on factors such as the thickness of the resist film to be formed.

[0164] <Acid Generator Component (B)> The resist composition of this embodiment includes, in addition to the component (A), an acid generator component (B) that generates an acid upon exposure. The acid generator component (B) includes a compound (B0) represented by the following general formula (b0). Compound (B0) (component (B0)) is a compound represented by the following general formula (b0). By including the component (B0), the resist composition of this embodiment can achieve good sensitivity during resist pattern formation.

[0165] [In the formula, Ar represents an aromatic ring. ０ represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. ０ represents a divalent linking group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０ represents an organic group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０ represents an organic group. n01 is an integer of 1 or more as long as the valence allows. n02 is an integer of 0 or more as long as the valence allows. When n01 is an integer of 2 or more, a plurality of Rf ０ When n02 is an integer of 2 or more, a plurality of Rb ０ may be the same or different, m is an integer of 1 or more, and M ｍ＋ represents an m-valent cation, where Rf ０ , Rb ０ , and M ｍ＋does not include a trifluoromethyl group (except when it results in a structure represented by the following general formula (np1)) and a difluoromethylene group (except when it results in a structure represented by the following general formula (np2) or (np3)).

[0166] [In the formula, X １ Ha-OR １ , -N(R ２ ) R １ or -N(R １ ) ２ represents. ２ represents a methyl group, a monovalent aromatic hydrocarbon group which may have a substituent, -OR ３ , -SR ３ , or -NR ３ R ４ represents. ３ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, a carbonyl group, -OR １ , -SR １ , -N(R ２ ) R １ or -N(R １ ) ２ Represents R １ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, or a carbonyl group. ２ , R ３ , and R ４ each independently represents a hydrogen atom, a methyl group, or a monovalent aromatic hydrocarbon group which may have a substituent.

[0167] In the formulas (np1) to (np3), X １ -OR in １ , -N(R ２ ) R １ or -N(R １ ) ２ In the formula, CF ３ In the formula (np2), X is bonded to O or N. ２ -OR in ３ , -SR ３ , or -NR ３ R ４ In the formula, CF ２ The bond to X is O, S, or N.３ -OR in １ , -SR １ , -N(R ２ ) R １ or -N(R １ ) ２ In the formula, CF ２ is bonded to O, S, or N.

[0168] {Anion Moiety of Component (B0)} In the formula (b0), the aromatic ring in Ar is Ra' in the formula (a1-r-1). ３ is an aromatic hydrocarbon group, examples of which include the same aromatic rings as those contained in the aromatic hydrocarbon group, and are not particularly limited as long as they are cyclic conjugated systems 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. More specific examples 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 -O-, -C(=O)-O-, -S-, and -S(=O) ２ -, -S(=O) ２ -O-, -N-, etc. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. ０ As the aromatic ring in the above, benzene or naphthalene is preferable, and benzene is more preferable.

[0169] In the formula (b0), Rf ０ In the formula, the fluorinated alkyl group having 1 to 5 carbon atoms is preferably a linear or branched fluorinated 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, in which some of the hydrogen atoms are substituted with fluorine atoms. ０ is preferably a fluorine atom.

[0170] In the formula (b0), L ０The divalent linking group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms in the formula (a2-1) is not particularly limited, but examples thereof include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have a substituent, and divalent linking groups containing a hetero atom. ２１ Examples of the divalent linking group include the same divalent hydrocarbon group which may have a substituent and the same divalent linking group containing a hetero atom as those mentioned in the description of the divalent linking group in ０ The divalent linking group in the formula (I) is composed of an atom selected from the group consisting of a carbon atom, a hydrogen atom, a sulfur atom, an oxygen atom, and a nitrogen atom). ０ is preferably a divalent linking group containing —C(═O)—O— or a divalent linking group containing —O—C(═O)—. ０ 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 further preferably a methylene group or an ethylene group.

[0171] In the formula (b0), Yb ０ The organic group consisting of atoms selected from the group consisting of carbon, hydrogen, sulfur, oxygen, and nitrogen atoms in the formula (I) is preferably an organic group other than an acid-dissociable group. Among these, the organic group other than an acid-dissociable group is more preferably a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent.

[0172] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group which does not have aromaticity. Furthermore, the aliphatic hydrocarbon group is preferably saturated.

[0173] Yb ０The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. ０ Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. ０ Specific examples of the aromatic hydrocarbon group in include groups in which one hydrogen atom has been removed from the aromatic ring (aryl groups: for example, phenyl group, naphthyl group, etc.), and groups in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, etc.). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 or 2, and particularly preferably 1.

[0174] Yb ０Examples of the cyclic aliphatic hydrocarbon group in the formula (I) include aliphatic hydrocarbon groups containing a ring within their structure. Examples of aliphatic hydrocarbon groups containing a ring within their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed within a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be either a polycyclic group or a monocyclic group. Preferred monocyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a monocycloalkane. Preferred monocycloalkanes have 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. Preferred polycyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkanes include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ] Polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as decane and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton, are more preferred.

[0175] Among them, Yb ０ The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0176] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ )２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ -] and the like. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0177] Also, Yb ０ The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specifically, lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7), —SO 2 represented by the general formulae (a5-r-1) to (a5-r-4), ２ -containing cyclic groups, and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16), respectively, in which * represents a bond bonded to Ar in formula (b0).

[0178]

[0179] Yb ０ Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms. 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. The halogen atom as a substituent is preferably a fluorine atom, a bromine atom, or an iodine atom. Examples of the halogenated alkyl group as a substituent 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 halogen atoms. The carbonyl group as a substituent is a methylene group (-CH) constituting a cyclic hydrocarbon group. ２ -) is a group that substitutes

[0180] Yb ０The cyclic hydrocarbon group in may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a bridged ring polycyclic skeleton to which one or more aromatic rings are fused. Specific examples of the bridged ring polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. １０１ Specific examples of the fused cyclic group in formula (b0) include groups represented by the following formulae (r-br-1) to (r-br-2). ０ represents a bond bonded to

[0181]

[0182] Yb ０ Examples of the substituent that the fused cyclic group in the formula (I) may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, etc. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused cyclic group can be selected from the group consisting of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused cyclic group described above in R １０１ Examples of the aromatic hydrocarbon group as a substituent of the fused cyclic group include a group in which one hydrogen atom has been removed from an aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of the alicyclic hydrocarbon group as a substituent of the fused cyclic group include a group in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0２，６ a group in which one hydrogen atom has been removed from a polycycloalkane such as decane or tetracyclododecane; a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7); a —SO 2 group represented by each of the general formulae (a5-r-1) to (a5-r-4), ２ -containing cyclic group: heterocyclic groups represented by the above formulae (r-hr-7) to (r-hr-16), respectively.

[0183] A chain alkyl group which may have a substituent: Yb ０ The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0184] A chain alkenyl group which may have a substituent: Yb ０ The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the above chain alkenyl groups, a linear alkenyl group is preferred, a vinyl group or a propenyl group is more preferred, and a vinyl group is particularly preferred.

[0185] Yb ０Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, the above-mentioned Yb ０ Examples of the cyclic groups include the cyclic groups shown in the formula:

[0186] Among the above, Yb ０ is preferably a cyclic group which may have a substituent, and more preferably an alicyclic group which may have a substituent. More specific examples of the alicyclic group include a phenyl group, a naphthyl group, and a group in which one or more hydrogen atoms have been removed from a polycycloalkane; a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7); and an —SO group represented by each of the general formulae (a5-r-1) to (a5-r-4). ２ -containing cyclic groups are preferred, and include groups in which one or more hydrogen atoms have been removed from a polycycloalkane or -SO ２ A -containing cyclic group is more preferred, and an adamantyl group or an -SO ２ -containing cyclic groups are more preferred.

[0187] When the cyclic hydrocarbon group has a substituent, the substituent is preferably a hydroxyl group.

[0188] In the formula (b0), Rb ０ The organic group in is preferably 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. ０ Examples of the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, and the chain alkenyl group which may have a substituent are the same as those mentioned in the description of the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, and the chain alkenyl group which may have a substituent.

[0189] In the formula (b0), n01 is not particularly limited as long as the valence allows, but is preferably an integer of 2 or more, and more preferably the maximum integer allowed by the valence. When n01 is an integer of 2 or more, a plurality of Rf ０ are not particularly limited, but are preferably the same.

[0190] In the formula (b0), n02 is preferably 0 or 1, and more preferably 0.

[0191] In the formulas (np1) to (np3), X ３ and R １ The monovalent aromatic hydrocarbon group which may have a substituent in the above formula (a1-r-1) is not particularly limited, but includes Ra' ３ R Ｐ１ In the formulae (np1) to (np3), X ２ , R ２ , R ３ , and R ４ The divalent aromatic hydrocarbon group which may have a substituent in the above formula (a1-r-1) is not particularly limited, but may be any of Ra' ３ R Ｐ２ The divalent aromatic hydrocarbon groups are the same as those in the above.

[0192] A good example of the compound (B0) is a compound (B0') represented by the following general formula (b0'): The compound (B0') has a perfluorobenzene skeleton in the anion moiety.

[0193] [wherein, Rf ０１ represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. ０１ represents a divalent linking group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０１ represents an organic group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０１ represents an organic group. n011 is an integer of 1 or more, n021 is an integer of 0 or more, and n011 + n022 ≦ 4. When n011 is an integer of 2 or more, a plurality of Rf ０１ When n021 is an integer of 2 or more, a plurality of Rb ０１ may be the same or different, m is an integer of 1 or more, and M ｍ＋represents an m-valent cation, where Rf ０１ , Rb ０１ , and M ｍ＋ does not include a trifluoromethyl group (except when it results in a structure represented by the following general formula (np1)) and a difluoromethylene group (except when it results in a structure represented by the following general formula (np2) or (np3)).

[0194] [In the formula, X １ Ha-OR １ , -N(R ２ ) R １ or -N(R １ ) ２ represents. ２ represents a methyl group, a monovalent aromatic hydrocarbon group which may have a substituent, -OR ３ , -SR ３ , or -NR ３ R ４ represents. ３ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, a carbonyl group, -OR １ , -SR １ , -N(R ２ ) R １ or -N(R １ ) ２ Represents R １ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, or a carbonyl group. ２ , R ３ , and R ４ each independently represents a hydrogen atom, a methyl group, or a monovalent aromatic hydrocarbon group which may have a substituent.

[0195] In formula (b0'), Rf ０１ The fluorinated alkyl group having 1 to 5 carbon atoms in Rf is preferably a linear or branched fluorinated 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, in which some or all of the hydrogen atoms have been substituted with fluorine atoms. ０１ is preferably a fluorine atom.

[0196] In formula (b0'), L ０１ In the general formula (b0), the divalent linking group consisting of an atom selected from the group consisting of a carbon atom, a hydrogen atom, a sulfur atom, an oxygen atom, and a nitrogen atom includes L ０ Examples of the divalent linking group include the same as the divalent linking group in L ０１ is preferably a divalent linking group containing —C(═O)—O— or a divalent linking group containing —O—C(═O)—. ０１ 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 further preferably a methylene group or an ethylene group.

[0197] In formula (b0'), Yb ０１ The organic group in Yb is preferably an organic group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms, and is preferably 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. ０１ In the general formula (b0), the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, or the chain alkenyl group which may have a substituent includes Yb ０ Examples of the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, and the chain alkenyl group which may have a substituent are the same as those mentioned in the description of the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, and the chain alkenyl group which may have a substituent.

[0198] In formula (b0'), Rb ０１ The organic group in the formula (b0) is preferably 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. ０ Examples of the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, and the chain alkenyl group which may have a substituent are the same as those mentioned in the description of the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, and the chain alkenyl group which may have a substituent.

[0199] In formula (b0'), n011 is preferably an integer of 1 or more and 4 or less, more preferably an integer of 2 or more and 4 or less, further preferably 2 or 3, and particularly preferably 4. When n011 is an integer of 2 or more, a plurality of Rf ０１ may be the same or different, but are preferably the same. In formula (b0'), n021 is preferably an integer of 0 or more and 3 or less, more preferably an integer of 0 or more and 2 or less, even more preferably 0 or 1, and particularly preferably 0.

[0200] In the formulas (np1) to (np3), X ３ and R １ The monovalent aromatic hydrocarbon group which may have a substituent in the above formula (a1-r-1) is not particularly limited, but includes Ra' ３ R Ｐ１ In the formulae (np1) to (np3), X ２ , R ２ , R ３ , and R ４ The divalent aromatic hydrocarbon group which may have a substituent in the above formula (a1-r-1) is not particularly limited, but may be any of Ra' ３ R Ｐ２ The divalent aromatic hydrocarbon groups are the same as those in the above.

[0201] Specific examples of the anion moiety of component (B0) include, but are not limited to, the following.

[0202]

[0203]

[0204] The anion moiety of the component (B0) is preferably one selected from the anion moieties represented by the formulas (b0-an-1) to (b0-an-12). Alternatively, from the viewpoint of easier improvement in sensitivity, the formulas (b0-an-1) to (b0-an-5) are more preferred, (b0-an-2) or (b0-an-3) are even more preferred, and (b0-an-3) is particularly preferred. Alternatively, from the viewpoint of achieving both high sensitivity and reduced environmental impact, the anion moiety is more preferably one selected from the anion moieties represented by the formulas (b0-an-1) to (b0-an-5), (b0-an-2) or (b0-an-3) are more preferred, and (b0-an-3) is particularly preferred.

[0205] {Cation moiety of component (B0)} In the formulas (b0) and (b0′), M ｍ＋ The m-valent cation in is not particularly limited, but is preferably an organic cation, more preferably an onium cation, and even more preferably a sulfonium cation or an iodonium cation. ｍ＋ Examples of the cation include organic cations represented by the following general formulas (ca-1) to (ca-3).

[0206] [In the formula, R ２０１ ~R ２０７ , and R ２１１ ~R ２１２ R each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. ２０１ ~R ２０３ , R ２０６ ~R ２０７ , R ２１１ ~R ２１２ may be bonded to each other to form a ring together with the sulfur atom in the formula. ２０８ ~R ２０９ R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ２１０ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an SO ２ -containing cyclic group. ２０１ represents —C(═O)— or —C(═O)—O—. ２０１each independently represents an arylene group, an alkylene group, or an alkenylene group; x is 1 or 2. ２０１ represents a (x+1)-valent linking group.

[0207] In the above general formulas (ca-1) to (ca-5), R ２０１ ~R ２０７ , and R ２１１ ~R ２１２ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２０１ ~R ２０７ , and R ２１１ ~R ２１２ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７ , and R ２１１ ~R ２１２ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２０１ ~R ２０７ , and R ２１０ ~R ２１２ Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulae (ca-r-1) to (ca-r-7):

[0208] [In the formula, R' ２０１ are each independently a hydrogen atom, 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.

[0209] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group which does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0210] R' ２０１The aromatic hydrocarbon group in R' is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. ２０１ Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in R' include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. ２０１ Specific examples of the aromatic hydrocarbon group in the formula (I) include groups in which one hydrogen atom has been removed from the aromatic ring (aryl groups: for example, phenyl group, naphthyl group, etc.), and groups in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0211] R' ２０１Examples of the cyclic aliphatic hydrocarbon group in the formula (I) include aliphatic hydrocarbon groups containing a ring within their structure. Examples of aliphatic hydrocarbon groups containing a ring within their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed within a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be either a polycyclic group or a monocyclic group. Preferred monocyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a monocycloalkane. Preferred monocycloalkanes have 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. Preferred polycyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkanes include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ] Polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as decane and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton, are more preferred.

[0212] Among them, R' ２０１ The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0213] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２-], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, —CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0214] Also, R' ２０１ The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specifically, lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7), —SO 2 represented by the general formulae (a5-r-1) to (a5-r-4), ２ -containing cyclic groups, and other heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16), respectively.

[0215] R' ２０１ Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. The halogen atom as a substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, in which some or all of the hydrogen atoms have been substituted with the halogen atoms. The carbonyl group as a substituent is a methylene group (-CH ２ -) is a group that substitutes

[0216] A chain alkyl group which may have a substituent: R' ２０１The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0217] A chain alkenyl group which may have a substituent: R' ２０１ The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of linear alkenyl groups include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of branched alkenyl groups include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the above chain alkenyl groups, linear alkenyl groups are preferred, with a vinyl group and a propenyl group being more preferred, and a vinyl group being particularly preferred.

[0218] R' ２０１ Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, the above-mentioned R' ２０１ Examples of the cyclic groups include the cyclic groups shown in the formula:

[0219] R' ２０１In addition to the above-mentioned optionally substituted cyclic groups, optionally substituted chain alkyl groups, and optionally substituted chain alkenyl groups, examples of the optionally substituted cyclic groups or optionally substituted chain alkyl groups include those similar to the acid-dissociable group represented by formula (a1-r-2) above.

[0220] Among them, R' ２０１ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane; a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7); ２ -containing cyclic groups are preferred.

[0221] In the above general formulas (ca-1) to (ca-3), R ２０１ ~R ２０３ , R ２０６ ~R ２０７ , R ２１１ ~R ２１２ When they are bonded to each other to form a ring together with the sulfur atom in the formula, they are not substituted with heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, or with carbonyl groups, -SO-, -SO ２ -, -SO ３ -, -COO-, -CONH- or -N(R Ｎ )-(the R Ｎ is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0222] R ２０８ ~R ２０９each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when they are alkyl groups, they may be bonded to each other to form a ring.

[0223] R ２１０ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an SO ２ -containing cyclic group. ２１０ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２１０ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２１０ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２１０ SO which may have a substituent ２ Examples of the -containing cyclic group include "-SO ２ -containing polycyclic group" is preferred, and a group represented by the above general formula (a5-r-1) is more preferred.

[0224] Y ２０１ each independently represents an arylene group, an alkylene group, or an alkenylene group. ２０１ The arylene group in the formula (b-1) is １０１ Examples of the aromatic hydrocarbon group in the above formula include groups in which one hydrogen atom has been removed from the aryl groups exemplified in the formula Y. ２０１ The alkylene group and alkenylene group in the formula (b-1) are １０１ Examples of the chain alkyl group and the chain alkenyl group include groups in which one hydrogen atom has been removed from the groups exemplified above as the chain alkyl group and the chain alkenyl group.

[0225] In the formula (ca-4), x is 1 or 2. ２０１ is a (x+1)-valent linking group, i.e., a divalent or trivalent linking group. ２０１ The divalent linking group in the formula (a2-1) is preferably a divalent hydrocarbon group which may have a substituent. ２１Examples of the divalent hydrocarbon groups which may have a substituent include those shown in the following. ２０１ The divalent linking group in may be linear, branched, or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferred. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferred. ２０１ The trivalent linking group in ２０１ Examples of the divalent linking group include a group in which one hydrogen atom has been removed from the divalent linking group shown in the formula: and a group in which the divalent linking group is further bonded to the divalent linking group shown in the formula: ２０１ The trivalent linking group in the formula (I) is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0226] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-67).

[0227]

[0228]

[0229] [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.]

[0230]

[0231] [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 ~R ２１２ The substituents are the same as those exemplified as the substituents that may be possessed by

[0232]

[0233] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0234] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0235]

[0236] In the formulas (np1) to (np3), X ３ and R １ The monovalent aromatic hydrocarbon group which may have a substituent in the above formula (a1-r-1) is not particularly limited, but includes Ra' ３ R Ｐ１ In the formulae (np1) to (np3), X ２ , R ２ , R ３ , and R ４ The divalent aromatic hydrocarbon group which may have a substituent in the above formula (a1-r-1) is not particularly limited, but may be any of Ra' ３ R Ｐ２ The divalent aromatic hydrocarbon groups are the same as those in the above.

[0237] Among the above, M ｍ＋ is preferably a cation selected from the group consisting of cations represented by the general formulae (ca-1) to (ca-3) above, and more preferably a cation represented by the general formula (ca-1).

[0238] Specific examples of the component (B0) are listed below, but are not limited to these. In the following chemical formula, pKa represents the acid dissociation constant in DMSO. Here, "pKa (acid dissociation constant)" refers to a commonly used index indicating the acid strength of a target substance. In this specification, pKa is a value at a temperature condition of 25°C. The pKa value can be determined by measurement using known techniques. Alternatively, a calculated value using known software such as "ACD / Labs" (trade name, manufactured by Advanced Chemistry Development Co.) can also be used. The component (B0) contained in the resist composition of this embodiment may contain a substance with a pKa of less than 0, and a larger negative value is preferred because the acid strength increases. For example, a pKa of -3 or less is preferred, and -4 or less is more preferred.

[0239]

[0240]

[0241] The component (B0) is preferably one selected from the anion moieties represented by the formulas (B0-1) to (B0-12). Alternatively, from the viewpoint of easier improvement in sensitivity, the formulas (B0-1) to (B0-6) are more preferred, (B0-2) or (B0-3) are even more preferred, and (B0-3) is particularly preferred. Alternatively, from the viewpoint of achieving both high sensitivity and reduced environmental impact, the component (B0) is more preferably one selected from the anion moieties represented by the formulas (B0-1) to (B0-6), (B0-2) or (B0-3) are more preferred, and (B0-3) is particularly preferred.

[0242] In the resist composition of this embodiment, the component (B0) may be used alone, or two or more types may be used in combination. In the resist composition of this embodiment, the amount of the component (B0) relative to 100 parts by mass of the component (A) is preferably less than 40 parts by mass, more preferably 1 to 30 parts by mass, and even more preferably 3 to 25 parts by mass. By ensuring that the amount of the component (B0) falls within the above-mentioned preferred range, sufficient pattern formation is achieved. Furthermore, this is preferable because 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 improved.

[0243] <Other Components> The resist composition of this embodiment may further contain other components in addition to the above-mentioned components (A) and (B0). Examples of other components include the following components (B1), (D), (E), (F), and (S). It is preferable that the other components do not include a PFAS compound.

[0244] <Acid Generator Component (B1) (excluding compounds corresponding to compound (B0))> The resist composition of this embodiment may or may not contain an acid generator component (B1) (excluding compounds corresponding to compound (B0)) that generates acid upon exposure, and it is preferable that the resist composition does not contain such an acid generator. There are no particular limitations on the component (B1), and any of the components that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl- or bisarylsulfonyl diazomethanes and poly(bissulfonyl)diazomethanes, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0245] Examples of the onium salt acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)"):

[0246] [In the formula, R １０１ and R １０４ ~R １０８ R are each independently 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. １０４ and R １０５ may be bonded to each other to form a ring structure. １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０１ is a divalent linking group containing an oxygen atom or a single bond. １０１ ~V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. １０１ ~L １０２ are each independently a single bond or an oxygen atom. １０３ ~L １０５ each independently represents a single bond, —CO— or —SO ２ m is an integer of 1 or more, and M ｍ＋ is an m-valent onium cation.

[0247] {Anion moiety} Anion in component (b-1) In formula (b-1), R １０１ 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.

[0248] In formula (b-1), Y １０１ is a single bond or a divalent linking group containing an oxygen atom. １０１ is a divalent linking group containing an oxygen atom, １０１ may contain an atom other than an oxygen atom. Examples of atoms other than an oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom. Examples of the divalent linking group containing an oxygen atom include linking groups represented by the following general formulas (y-a1-1) to (y-a1-7). In the following general formulas (y-a1-1) to (y-a1-7), R in the above formula (b-1) １０１ The bond to V' in the following general formulae (y-al-1) to (y-al-7) is１０１ is.

[0249] [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.

[0250] V' １０２ The divalent saturated hydrocarbon 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.

[0251] V' １０１ and V' １０２ The alkylene group in V' may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group. １０１ and V' １０２ Specific examples of the alkylene group in ２ -]; -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; ethylene groups [-CH ２ CH ２ -]; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２-, etc.; a trimethylene group (n-propylene group) [—CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ an alkyltrimethylene group such as -; a tetramethylene group [-CH ２ CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ -, etc.; an alkyltetramethylene group such as a pentamethylene group [—CH ２ CH ２ CH ２ CH ２ CH ２ -]. Also, V' １０１ or V' １０２ In the formula (a1-r-1), some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by Ra' in the formula (a1-r-1). ３ A divalent group obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group) of the above formula (I) is preferred, and a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferred.

[0252] Y １０１ As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, and the linking groups represented by the above formulas (y-al-1) to (y-al-5) are more preferable.

[0253] In formula (b-1), V １０１ is a single bond, an alkylene group or a fluorinated alkylene group. １０１The alkylene group and fluorinated alkylene group in the formula (I) preferably have 1 to 4 carbon atoms. １０１ is preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0254] In formula (b-1), R １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０２ is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0255] Specific examples of the anion moiety represented by the formula (b-1) include, for example, Y １０１ When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; １０１ When is a divalent linking group containing an oxygen atom, examples of the anion include anions represented by any one of the following formulae (an-1) to (an-3).

[0256] [In the formula, R” １０１ R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by each of the above chemical formulas (r-hr-6) to (r-hr-16), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a chain alkyl group which may have a substituent, or an aromatic cyclic group which may have a substituent. １０２ represents an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the formula (r-br-1) or (r-br-2) above, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1), (a2-r-3) to (a2-r-7) above, or —SO ２ -containing cyclic group. １０３ V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. １０１ is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. １０２is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; each v" is independently an integer of 0 to 3; each q" is independently an integer of 0 to 20; and n" is 0 or 1.

[0257] R” １０１ , R” １０２ and R” １０３ The aliphatic cyclic group which may have a substituent is represented by R １０１ The substituent is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in the formula (b-1). １０１ Examples of the substituents that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1).

[0258] R” １０１ and R” １０３ The aromatic cyclic group which may have a substituent in the formula (b-1) is R １０１ The substituent is preferably a group exemplified as an aromatic hydrocarbon group in the cyclic hydrocarbon group in the formula (b-1). １０１ Examples of the substituents that may substitute the aromatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0259] R” １０１ The chain alkyl group which may have a substituent in the formula (b-1) is R １０１ R" is preferably a group exemplified as a chain alkyl group in １０３ The chain alkenyl group which may have a substituent is R １０１ Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0260] Anion in component (b-2) In formula (b-2), R １０４ , R １０５ are each independently 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 is represented by R １０１ However, R １０４ , R １０５may be bonded to each other to form a ring. １０４ , R １０５ is preferably a chain alkyl group which may have a substituent, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms in the chain alkyl group is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. １０４ , R １０５ The number of carbon atoms in the chain alkyl group of R is preferably as small as possible within the above range of carbon atoms, for reasons such as good solubility in resist solvents. １０４ , R １０５ In the chain alkyl group, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the improved transparency to high-energy light of 250 nm or less and electron beams, which is preferable. The proportion of fluorine atoms in the chain alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V １０２ , V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-1). １０１ In formula (b-2), L １０１ , L １０２ are each independently a single bond or an oxygen atom.

[0261] Anion in component (b-3) In formula (b-3), R １０６ ~R １０８ are each independently 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 is represented by R １０１ In formula (b-3), L １０３ ~L １０５ each independently represents a single bond, —CO— or —SO ２ - is.

[0262] Among the above, the anion moiety of component (B1) is preferably the anion in component (b-1). Among these, anions represented by any of general formulas (an-1) to (an-3) above are more preferred, anions represented by general formula (an-1) or (an-2) are even more preferred, and anions represented by general formula (an-2) are particularly preferred.

[0263] {Cation moiety} Mm ＋ The cation in is preferably an organic cation, more preferably an onium cation, and particularly preferably a sulfonium cation or an iodonium cation.

[0264] M ｍ＋ Examples of the organic cations include those represented by the above general formulas (ca-1) to (ca-3). ｍ＋ is preferably a cation represented by the general formula (ca-1).

[0265] <<Base Component (D)>> In addition to the component (A), the resist composition of this embodiment may further contain a base component (component (D)) that traps acid generated upon exposure (i.e., controls the diffusion of acid). The component (D) acts as a quencher (acid diffusion controller) that traps acid generated in the resist composition upon exposure. Examples of the component (D) include a photodegradable base (D1) (hereinafter referred to as “component (D1)”) that decomposes upon exposure and loses its ability to control acid diffusion, and a nitrogen-containing organic compound (D2) (hereinafter referred to as “component (D2)”) that does not fall under the category of component (D1). Among these, the photodegradable base (component (D1)) is preferred because it is likely to enhance all of the properties of high sensitivity, reduced roughness, and suppressed coating defects.

[0266] Regarding the component (D1): By using a resist composition containing the component (D1), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. The component (D1) 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 (d1-1) (hereinafter referred to as "component (d1-1)"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"). The components (d1-1) to (d1-3) decompose and lose their acid diffusion controllability (basicity) in the exposed areas of the resist film, and therefore do not function as quenchers, but function as quenchers in the unexposed areas of the resist film.

[0267] [In the formula, Rd １ ~Rd ４ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the above, 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.

[0268] {Component (d1-1)} Anion portion In formula (d1-1), Rd １ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of the R' ２０１ Among these, Rd １is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1) to (a2-r-7), 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 via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the above formulas (y-al-1) to (y-al-5). Note that Rd １ In the above general formulas (y-al-1) to (y-al-7), when the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group has, as a substituent, a linking group represented by each of the general formulae (y-al-1) to (y-al-7), Rd in formula (d1-1) １ The carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the formula (y-al-1) to (y-al-7) is bonded to V' １０１ 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). Suitable examples of the aliphatic cyclic group include adamantane, norbornane, isobornane, tricyclo[5.2.1.0], ２，６

[0033] More preferably, it is a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as decane or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; and branched alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl groups.

[0269] 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 an atom other than a fluorine atom. Examples of the atom other than a fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0270] Specific examples of preferred anion moieties of component (d1-1) are shown below.

[0271]

[0272] ...cation moiety In formula (d1-1), M ｍ＋ is an m-valent organic cation. ｍ＋ Suitable examples of the organic cation include the same as the cations represented by the general formulae (ca-1) to (ca-3), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the general formulae (ca-1-1) to (ca-1-67) being even more preferred. One type of component (d1-1) may be used alone, or two or more types may be used in combination.

[0273] {Component (d1-2)} Anion portion In formula (d1-2), Rd ２ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ However, Rd ２ In the formula, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not substituted with fluorine). This makes the anion of component (d1-2) an appropriately weak acid anion, improving the quenching ability of component (D). ２ The alkyl group is preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. The aliphatic cyclic group includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0２，６ ] a group (which may have a substituent) in which one or more hydrogen atoms have been removed from decane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor, or the like. ２ The hydrocarbon group may have a substituent, and the substituent may be Rd １ Examples of the substituents include the same as those that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0274] Specific examples of preferred anion moieties of component (d1-2) are shown below.

[0275]

[0276] In formula (d1-2), M ｍ＋ is an m-valent organic cation, and M in the formula (d1-1) ｍ＋ The component (d1-2) may be used alone or in combination of two or more.

[0277] {Component (d1-3)} Anion portion In formula (d1-3), Rd ３ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ Among these, a fluorinated alkyl group is preferred, and the Rd １ The same fluorinated alkyl groups as those mentioned above are more preferred.

[0278] In formula (d1-3), Rd ４ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group, which may have a substituent, is preferable. ４The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. ４ A part of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, etc. ４ The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0279] Rd ４ 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.

[0280] Rd ４ The cyclic group in ２０１ Examples thereof include cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclo[5.2.1.0], and the like. ２，６ ] An alicyclic group in which one or more hydrogen atoms have been removed from a cycloalkane such as decane or tetracyclododecane, or an aromatic group such as a phenyl group or naphthyl group is preferred. 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 ArF or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency, and exhibits excellent sensitivity and lithography properties.

[0281] In formula (d1-3), Yd １ represents a single bond or a divalent linking group. １The divalent linking group in is not particularly limited, but examples thereof 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. ２１ Examples of the divalent linking group include the same divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom as those mentioned in the description of the divalent linking group in １ 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 further preferably a methylene group or an ethylene group.

[0282] Specific examples of preferred anion moieties of component (d1-3) are shown below.

[0283]

[0284]

[0285] In formula (d1-3), M ｍ＋ is an m-valent organic cation, and M in the formula (d1-1) ｍ＋ The component (d1-3) may be used alone or in combination of two or more.

[0286] The component (D1) may be any one of the above components (d1-1) to (d1-3), or a combination of two or more of them. When the resist composition contains the component (D1), the amount of the component (D1) in the resist composition is preferably 0.2 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and even more preferably 0.7 to 8 parts by mass, per 100 parts by mass of the component (A1). When the amount of the component (D1) is at least as large as the preferred lower limit, particularly favorable lithography properties and resist pattern shape are more likely to be obtained. On the other hand, when the amount is at most as large as the upper limit, good sensitivity can be maintained and excellent throughput can also be achieved.

[0287] Production method of component (D1): The production methods of the components (d1-1) and (d1-2) are not particularly limited, and they can be produced by known methods. The production method of component (d1-3) is also not particularly limited, and it can be produced, for example, by the method described in US 2012-0149916.

[0288] Although the compound of component (D1) has been shown as an example of a base component (component (D)) that traps acid generated upon exposure, the compound of component (D1) may also be used as component (B). For example, in the resist composition of this embodiment, the compound of component (D1) may be used as component (B), and a compound that generates an acid with a lower acidity than the acid generated by the compound of component (D1) upon exposure may be used as component (D). Furthermore, in the resist composition of this embodiment, the compound of component (D1) may be used as component (B), and the component (D2), described below, may be used as component (D).

[0289] Regarding the (D2) component The (D) component may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the above-mentioned (D1) component. The (D2) component is not particularly limited as long as it acts as an acid diffusion controller and does not fall under the category of the (D1) component, and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are more preferred. The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of the aliphatic amine include ammonia NH ３Examples of the amine include amines in which at least one hydrogen atom is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), and cyclic amines. Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0290] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of aliphatic monocyclic amines include piperidine and piperazine. Specific examples of aliphatic polycyclic amines include those having 6 to 10 carbon atoms, such as 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0291] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, and the like, with triethanolamine triacetate being preferred.

[0292] Furthermore, the component (D2) may be an aromatic amine, such as 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole, or a derivative thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, or 2,6-di-tert-butylpyridine.

[0293] The component (D2) may be used singly, or in combination of two or more types. When the resist composition contains the component (D2), the amount of the component (D2) within the resist composition is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A1). By ensuring that the amount is within this range, the resist pattern shape and stability over time during storage can be improved.

[0294] <<At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxo acids, and derivatives thereof>> The resist composition of this embodiment may contain at least one compound (E) (hereinafter referred to as "component (E)") selected from the group consisting of organic carboxylic acids, phosphorus oxo acids, and derivatives thereof as an optional component for the purposes of preventing sensitivity degradation and improving resist pattern shape and post-exposure stability. Specific examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, with salicylic acid being preferred. Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred. Examples of derivatives of phosphorus oxo acids include esters in which the hydrogen atoms of the above oxo acids are substituted with hydrocarbon groups, with examples of the hydrocarbon groups being alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of phosphoric acid derivatives include phosphate esters such as di-n-butyl phosphate and diphenyl phosphate. Examples of phosphonic acid derivatives include phosphonate esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid. In the resist composition of this embodiment, the component (E) may be used alone or in combination with two or more different compounds. When the resist composition contains the component (E), the amount of the component (E) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the component (A). By using the component (E) in the above range, sensitivity, lithography properties, and the like are improved.

[0295] <Fluorine Additive Component (F)> The resist composition of this embodiment may contain a fluorine additive component (hereafter referred to as "component (F)") as a hydrophobic resin. The component (F) is used to impart water repellency to the resist film, and by using it as a resin separate from the component (A), it is possible to improve lithography properties. As the component (F), for example, the fluorine-containing polymer compounds described in JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, and JP 2011-128226 A can be used. More specific examples of the component (F) include polymers having a structural unit (f1) represented by the following general formula (f1-1): This polymer is preferably a polymer (homopolymer) consisting solely of the structural unit (f1) represented by the following formula (f1-1): a copolymer of the structural unit (f1) with the structural unit (a1); or a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1), and is more preferably a copolymer of the structural unit (f1) with the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl(meth)acrylate or a structural unit derived from 1-methyl-1-adamantyl(meth)acrylate.

[0296] [wherein R is the same as defined above, and Rf １０２ and Rf １０３ Rf each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; １０２ and Rf １０３ may be the same or different. １ is an integer of 0 to 5, and Rf １０１ is an organic group containing a fluorine atom.

[0297] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as defined above. R is preferably a hydrogen atom or a methyl group. １０２ and Rf １０３The halogen atom in Rf is preferably a fluorine atom. １０２ and Rf １０３ Examples of the alkyl group having 1 to 5 carbon atoms in Rf include the same alkyl groups having 1 to 5 carbon atoms as those in R, and a methyl group or an ethyl group is preferred. １０２ and Rf １０３ Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is preferred. Among these, Rf １０２ and Rf １０３ In formula (f1-1), nf is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and still more preferably a hydrogen atom. １ is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0298] In formula (f1-1), Rf １０１ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. In addition, the hydrocarbon group containing a fluorine atom is preferably one in which 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more, because this increases the hydrophobicity of the resist film during immersion exposure. Among these, Rf １０１ is preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, more preferably a trifluoromethyl group, —CH ２ -CF ３ , -CH ２ -CF ２ -CF ３ , -CH(CF ３ ) ２ , -CH ２ -CH ２ -CF ３, -CH ２ -CH ２ -CF ２ -CF ２ -CF ２ -CF ３ is particularly preferred.

[0299] The weight-average molecular weight (Mw) of component (F) (based on polystyrene standards measured by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. When the Mw is below the upper limit of this range, the component has sufficient solubility in a resist solvent for use as a resist, while when the Mw is above the lower limit of this range, the resulting resist film has good water repellency. The dispersity (Mw / Mn) of component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0300] In the resist composition of this embodiment, the component (F) may be used either as a single type, or as a combination of two or more types. When the resist composition contains the component (F), the amount of the component (F) relative to 100 parts by mass of the component (A) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass.

[0301] <Organic Solvent Component (S)> The resist composition of this embodiment can be produced by dissolving the resist materials in an organic solvent component (hereafter referred to as "component (S)"). The component (S) can be any solvent that is capable of dissolving the individual components used to form a homogeneous solution, and any solvent can be appropriately selected from among those known as solvents for conventional chemically amplified resist compositions. In the resist composition of this embodiment, the component (S) can be used either alone or as a mixed solvent of two or more different solvents. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0302] Also preferred as component (S) is a mixed solvent of PGMEA and a polar solvent. The blending ratio (mass ratio) can be determined appropriately taking into account the compatibility of PGMEA with the polar solvent, etc. Another preferred component (S) is a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5. The amount of component (S) used is not particularly limited and is appropriately determined based on the coating film thickness and a concentration that allows application to a substrate, etc. Component (S) is generally used so that the solids concentration of the resist composition is within the range of 0.1 to 20 mass%, preferably 0.2 to 15 mass%.

[0303] The resist composition of this embodiment may further contain, if desired, compatible additives such as an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, or a dye.

[0304] In the resist composition of this embodiment, after dissolving the resist material in component (S), impurities may be removed using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous film, a filter made of a polyamideimide porous film, or a filter made of a polyimide porous film and a polyamideimide porous film. Examples of the polyimide porous film and the polyamideimide porous film include those described in JP 2016-155121 A.

[0305] The resist composition of this embodiment described above contains a resin component (A1) having a structural unit (a0) represented by general formula (a0-m), and an acid generator component (B) containing a compound (B0) represented by general formula (b0). In the resist composition of this embodiment, the structural unit (a0) contains a lactone-containing cyclic group, —SO ２The resist composition of this embodiment has at least one cyclic group selected from the group consisting of a -containing cyclic group, and a carbonate-containing ring. Furthermore, in the resist composition of this embodiment, compound (B0) has a perfluoroaromatic ring (excluding those corresponding to PFAS compounds). Therefore, by including an acid generator component (B) that includes compound (B0) represented by general formula (b0), the resist composition of this embodiment can reduce the environmental impact during resist pattern formation. By including a resin component (A1) that has a structural unit (a0) represented by general formula (a0-m), and an acid generator component (B) that includes compound (B0) represented by general formula (b0), the resist composition of this embodiment achieves the effects of excellent sensitivity during resist pattern formation and a reduced environmental impact. The reason for this effect is presumed to be as follows.

[0306] The structural unit (a0) is a lactone-containing cyclic group, —SO ２By containing at least one cyclic group selected from the group consisting of a -containing cyclic group and a carbonate-containing ring, when the component (A1) is used to form a resist film, for example, the acid diffusion length can be appropriately adjusted, the adhesion of the resist film to the substrate can be improved, and the solubility during development can be appropriately adjusted, resulting in improved lithography properties. In addition, by containing a perfluoroaromatic ring (excluding those that fall under the category of PFAS compounds), compound (B0) has a lower acid dissociation constant (pKa) and sufficient deprotection reactivity. Conventionally, compounds that do not fall under the category of PFAS compounds include compounds represented by the following chemical formula (B1-3), but the pKa of this compound is higher than that of the compounds represented by the following chemical formulas (B1-1) and (B1-2), respectively, that fall under the category of PFAS compounds. On the other hand, the pKa of compound (B0) represented by each of the following chemical formulas (B0-1) to (B0-5) tends to be closer to the pKa of compounds represented by the following chemical formulas (B1-1) and (B1-2), which are PFAS compounds, compared to a compound represented by the following chemical formula (B1-3), which is not a PFAS compound. That is, compound (B0) has a perfluoroaromatic ring (excluding those which are PFAS compounds), and thereby exhibits sufficient deprotection reactivity similar to that of compounds which are PFAS compounds. Therefore, by combining a resin component (A1) containing the structural unit (a0) with an acid generator component (B) containing compound (B0), acid diffusion can be controlled while maintaining sufficient deprotection reactivity, and the amount of the PFAS compound in the resist composition can be reduced, resulting in good sensitivity in resist pattern formation and a reduced environmental impact.

[0307]

[0308]

[0309] (Method of Forming a Resist Pattern) The method of forming a resist pattern pertaining to the second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition pertaining to the first aspect of the present invention, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. One embodiment of the method of forming a resist pattern can be exemplified by a method of forming a resist pattern as follows.

[0310] First, the resist composition of the above-described embodiment is applied to a support using a spinner or the like, and baked (post-applied bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150°C to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an ArF lithography device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with electron beams without a mask pattern. The resist film is then baked (post-exposure bake (PEB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150°C. Next, the resist film is developed. In the case of an alkali development process, the development is performed using an alkaline developer, and in the case of a solvent development process, a developer containing an organic solvent (organic developer) is used.

[0311] After the development treatment, a rinse treatment is preferably carried out. In the case of an alkaline development process, the rinse treatment is preferably a water rinse using pure water, and in the case of a solvent development process, a rinse solution containing an organic solvent is preferably used. In the case of a solvent development process, after the development treatment or rinse treatment, a treatment may be carried out to remove the developer or rinse solution adhering to the pattern using a supercritical fluid. After the development treatment or rinse treatment, drying is carried out. Furthermore, in some cases, a bake treatment (post-bake) may be carried out after the development treatment.

[0312] 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.

[0313] The wavelength used for exposure is not particularly limited, and exposure can be performed using an ArF excimer laser, a KrF excimer laser, or a F ２ Radiation such as excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. The method of forming a resist pattern of this embodiment is useful for exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam) in the step of exposing the resist film.

[0314] The exposure method for the resist film may be a normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be liquid immersion exposure (liquid immersion lithography). Liquid immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure apparatus is filled in advance with a solvent (immersion medium) having a refractive index greater than that of air, and exposure (immersion exposure) is performed in this state. The liquid immersion medium is preferably a solvent having a refractive index greater than that of air and less than that of the resist film to be exposed, such as water, a fluorine-based inert liquid, a silicon-based solvent, or a hydrocarbon-based solvent. Among these, water is preferably used as the liquid immersion medium.

[0315] An example of an alkaline developer used in the development treatment in the alkaline development process is a 0.1 to 10% by mass aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent that can dissolve component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0316] 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.

[0317] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0318] If necessary, known additives such as surfactants can be added to the organic developer.

[0319] 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).

[0320] The organic solvent contained in the rinse solution used in the rinsing treatment after development in the solvent development process can be appropriately selected from the organic solvents listed above as organic solvents used in the organic developer, as long as they do not easily dissolve the resist pattern. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used alone or in combination with two or more. They may also be used in combination with other organic solvents or water.

[0321] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method, such as a method of continuously applying 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).

[0322] The resist composition of the above-described embodiment and the various materials used in the resist pattern formation method of the above-described embodiment (e.g., resist solvent, developer, rinse, anti-reflective coating-forming composition, top coat-forming composition, etc.) preferably do not contain impurities such as metals, halogen-containing metal salts, acids, alkalis, or components containing sulfur atoms or phosphorus atoms. Examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, 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 of impurities (below the detection limit of the measuring device).

[0323] Other Embodiments The method of forming a resist pattern of the present embodiment may further include a step of forming a topcoat layer between the step of forming a resist film and the step of exposing the resist film.

[0324] When a step of forming a topcoat layer is included, a resist film is formed by PAB treatment in the same manner as described above. Next, a coating liquid for forming a topcoat layer is applied onto the resist film using a spinner or the like, and the coating liquid is applied for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150°C, for example, to form a topcoat layer. When a step of forming a topcoat layer is included, the step of exposing the resist film and the step of developing the exposed resist film to form a resist pattern are the same as described above.

[0325] The coating liquid for forming a top coat layer may be any liquid capable of forming a top coat layer, and may be appropriately selected from known coating liquids for forming a top coat layer. Specific examples include "TILC-323" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.).

[0326] According to the method of forming a resist pattern of the present embodiment described above, the resist composition described above is used, which results in good sensitivity when forming a resist pattern and also reduces the environmental impact.

[0327] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0328] <Production of Polymer Compounds> The polymer compounds (A1-1) to (A1-5) used in the present examples and the polymer compounds (A2-1) and (A2-2) used in the comparative examples were each obtained by radical polymerization using monomers that derive the structural units constituting each polymer compound in a predetermined molar ratio. The weight average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) of each obtained polymer compound were determined by GPC measurement (standard polystyrene equivalent). Furthermore, the copolymerization composition ratio (the proportion (molar ratio) of each structural unit in the structural formula) of each obtained polymer compound was determined by carbon-13 nuclear magnetic resonance spectroscopy (600 MHz_ １３ C-NMR).

[0329] The polymeric compounds (A1-1) to (A1-5) are shown below: In the following formulas, l, m, n, and o represent the proportion (molar ratio) of each structural unit.

[0330]

[0331] Polymer compound (A1-1): weight average molecular weight (Mw) 7000, molecular weight dispersity (Mw / Mn) 1.5, l / m=50 / 50. Polymer compound (A1-2): weight average molecular weight (Mw) 7000, molecular weight dispersity (Mw / Mn) 1.6, l / m=50 / 50. Polymer compound (A1-3): Weight average molecular weight (Mw) 7000, molecular weight dispersity (Mw / Mn) 1.5, l / m = 40 / 60. Polymer compound (A1-4): weight average molecular weight (Mw) 7000, molecular weight dispersity (Mw / Mn) 1.5, l / m=50 / 50. Polymer compound (A1-5): weight average molecular weight (Mw) 6900, molecular weight dispersity (Mw / Mn) 1.5, l / m / n / o=40 / 10 / 35 / 15.

[0332] The polymer compounds (A2-1) and (A2-2) are shown below: In the following formulas, l, m, n, and o represent the proportion (molar ratio) of each structural unit.

[0333]

[0334] Polymer compound (A2-1): weight average molecular weight (Mw) 7000, molecular weight dispersity (Mw / Mn) 1.6, l / m=50 / 50. Polymer compound (A2-2): weight average molecular weight (Mw) 7000, molecular weight dispersity (Mw / Mn) 1.5, l / m / n / o = 40 / 10 / 35 / 15.

[0335] <Preparation of Resist Compositions> (Examples 1 to 14, Comparative Examples 1 to 9) The components shown in Tables 1 and 2 were mixed and dissolved to prepare the resist compositions of each example.

[0336]

[0337]

[0338] In Tables 1 and 2 and the following Table 3, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0339] (A1)-1 to (A1)-5: the above polymeric compounds (A1-1) to (A1-5). (A2)-1, (A2)-2: the above polymeric compounds (A2-1), (A2-2).

[0340] (B0)-1 to (B0)-5: Acid generators composed of compounds represented by the following chemical formulas (B0-1) to (B0-5), respectively.

[0341]

[0342] (B1)-1 to (B1)-4: Acid generators consisting of compounds represented by the following chemical formulas (B1-1) to (B1-4), respectively.

[0343]

[0344] (D1)-1, (D1)-2: Acid diffusion controllers consisting of compounds represented by the following chemical formulas (D1-1) and (D1-2), respectively.

[0345]

[0346] (F1)-1: A polymer compound represented by the following chemical formula (F-1): The weight average molecular weight (Mw) calculated in terms of standard polystyrene, as determined by GPC measurement, is 25,000, and the molecular weight dispersity (Mw / Mn) is 1.5. １３ The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 80 / 20.

[0347]

[0348] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / cyclohexanone = 1920 / 700 / 870 (mass ratio). (S)-2: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / cyclohexanone = 1120 / 750 / 620 (mass ratio).

[0349] <Formation of Resist Pattern (LS Pattern) (No Topcoat Layer)> An organic antireflective coating composition "ARC29" (manufactured by Brewer Science) was applied onto a 12-inch silicon wafer using a spinner, and then baked on a hot plate at 205°C for 60 seconds to dry, thereby forming an organic antireflective coating having a thickness of 90 nm.

[0350] <<Step of Forming Resist Film>> Each of the resist compositions used in Examples 1 to 8 and Comparative Examples 1 to 5 was applied onto an antireflective film using a spinner, and the applied resist film was subjected to a pre-baking (PAB) treatment on a hot plate at 100°C for 60 seconds, followed by drying, to form a resist film with a thickness of 100 nm.

[0351] <<Step of Exposing Resist Film>> Next, the resist film was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (6% halftone) using an ArF immersion exposure system XT-1900Gi [manufactured by ASML; NA (numerical aperture) = 0.95, dipole (in / out = 0.668 / 0.829), with TE polarization, immersion medium: water]. Thereafter, a PEB treatment was performed at 120°C for 60 seconds.

[0352] <<Step of Developing to Form a Resist Pattern>> Next, alkaline development was performed for 10 seconds using a 2.38% by mass aqueous solution of TMAH (product name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C, followed by rinsing with pure water for 15 seconds and then shaking off and drying. As a result, in each example, a 1:1 line and space (LS) pattern with a line width of 70 nm and a pitch of 140 nm was formed.

[0353] <Formation of Resist Pattern (LS Pattern) (With Topcoat Layer)> An organic antireflective coating composition "ARC29" (manufactured by Brewer Science) was applied onto a 12-inch silicon wafer using a spinner, and then baked on a hot plate at 205°C for 60 seconds to dry, thereby forming an organic antireflective coating having a thickness of 90 nm.

[0354] <Step of Forming Resist Film> The resist composition used in Example 9 was applied onto the antireflective coating using a spinner, and then subjected to a pre-baking (PAB) treatment on a hot plate at 100°C for 60 seconds, followed by drying, to form a resist film with a thickness of 100 nm.

[0355] <<Step of Forming Top Coat Layer>> Next, a protective film-forming coating liquid "TILC-323" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied using a spinner onto the resist film having a thickness of 100 nm obtained by drying through the PAB treatment, and heated at 90°C for 60 seconds to form a top coat layer having a thickness of 35 nm.

[0356] <<Step of Exposing Resist Film>> Next, the resist film was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (6% halftone) using an ArF immersion exposure system XT-1900Gi [manufactured by ASML; NA (numerical aperture) = 0.95, dipole (in / out = 0.668 / 0.829), with TE polarization, immersion medium: water]. Thereafter, a PEB treatment was performed at 120°C for 60 seconds.

[0357] <<Step of Developing to Form a Resist Pattern>> Next, alkaline development was performed for 10 seconds using a 2.38% by mass aqueous solution of TMAH (product name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C, followed by rinsing with pure water for 15 seconds and then shaking off and drying. As a result, in each example, a 1:1 line and space (LS) pattern with a line width of 70 nm and a pitch of 140 nm was formed.

[0358] <Formation of Resist Pattern (CH Pattern) (With Topcoat Layer)> An organic antireflective coating composition "ARC95" (manufactured by Brewer Science) was applied onto a 12-inch silicon wafer using a spinner, and then baked on a hot plate at 205°C for 60 seconds to dry, thereby forming an organic antireflective coating with a thickness of 90 nm.

[0359] <<Step of Forming Resist Film>> Each of the resist compositions used in Examples 10 to 14 and Comparative Examples 6 to 9 was applied onto an antireflective coating using a spinner, and the applied resist composition was subjected to a pre-baking (PAB) treatment on a hot plate at 90°C for 60 seconds, followed by drying, to form a resist film with a thickness of 130 nm.

[0360] <<Step of Forming Top Coat Layer>> Next, a protective film-forming coating liquid "TILC-323" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied using a spinner onto the resist film having a thickness of 130 nm obtained by drying through the PAB treatment, and heated at 90°C for 60 seconds to form a top coat layer having a thickness of 35 nm.

[0361] <<Step of Exposing Resist Film>> Next, the resist film was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (6% halftone) using an ArF immersion exposure system XT-1900Gi [manufactured by ASML; NA (numerical aperture) = 1.35, Conventional (σ = 0.970), with TE polarization, immersion medium: water]. Thereafter, a PEB treatment was performed at 80°C for 60 seconds.

[0362] <<Step of Developing to Form a Resist Pattern>> Next, alkaline development was performed for 10 seconds using a 2.38% by mass aqueous solution of TMAH (product name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C, followed by rinsing with pure water for 15 seconds and then shaking off and drying. As a result, in each example, a contact hole (CH) pattern with a hole size of 68 nm and a pitch of 160 nm was formed.

[0363] [Evaluation of Optimal Exposure Dose (Eop)] The optimal exposure dose Eop (mJ / cm) at which an LS pattern of the target size is formed by the above <Formation of Resist Pattern (LS Pattern) (without Topcoat Layer)> and <Formation of Resist Pattern (LS Pattern) (with Topcoat Layer)> was evaluated. ２ ) was determined. In addition, the optimum exposure dose Eop (mJ / cm) at which a CH pattern of the target size is formed by <Formation of Resist Pattern (CH Pattern)> was determined. ２ These were called "Eop (mJ / cm ２ ) are shown in Tables 4 and 5.

[0364] [PFAS Compound Abundance Ratio] The PFAS compound abundance ratios in the Examples and Comparative Examples were determined by the following calculations 1 to 5.

[0365] A specific calculation method will be shown below using the resist composition used in Example 1 as an example. Note that, in the resist composition used in Example 1, structural unit 3 shown in the following general formula corresponds to the PFAS compound. In the following formula, l and m represent the proportion (molar ratio) of each structural unit.

[0366]

[0367] (Calculation 1: Calculation of Mass Ratio in Resist Film) Assuming that the total mass of the polymer compounds is 100 g, the mass ratios of the polymer compounds (A) and (F) and the low molecular weight compounds (B) and (D) in the resist film are calculated.

[0368] The mass ratio of the polymer compound in the resist film is calculated by dividing it into each structural unit. For example, when determining the mass ratio of structural unit 1 of polymer compound (A1-1), the mass ratio of structural unit 1 in the resist film can be calculated using the following formula. Note that the mass ratios of other polymer compounds can also be calculated using similar formulas.

[0369]

[0370] The mass ratio of the low molecular weight compound in the resist film, for example, when determining the mass ratio of the compound (B0-1), can be calculated using the following formula: The mass ratio of other low molecular weight compounds can also be determined using a similar formula.

[0371]

[0372] (Calculation 2: Conversion to Molar Ratio) The obtained mass ratio is converted to a molar ratio. For example, when converting the mass ratio of compound (B0-1) to a molar ratio, it can be calculated using the following calculation formula. Note that calculation 2 and subsequent calculations can be calculated using the same calculation formula for both high molecular weight compounds and low molecular weight compounds.

[0373]

[0374] (Calculation 3: Conversion to Molar Fraction in Film) The obtained molar ratio is converted to a molar fraction in film. For example, when converting the molar ratio of the compound (B0-1) to a molar fraction in film, it can be calculated by the following calculation formula.

[0375]

[0376] (Calculation 4: Conversion to In-Film Density) The obtained in-film molar fraction is converted to in-film density. For example, when converting the in-film molar fraction of the compound (B0-1) to in-film density, it can be calculated by the following calculation formula.

[0377]

[0378] Table 3 shows the molecular weight of each component used in the above calculation, as well as the mass ratio, molar ratio, molar fraction in the film, and density in the film of each component obtained by the above calculation.

[0379]

[0380] (Calculation 5: Calculation of PFAS compound abundance ratio) The PFAS compound abundance ratio is calculated based on the obtained in-film density. For example, the PFAS compound abundance ratio in Example 1 can be calculated by the following calculation formula.

[0381]

[0382] The PFAS compound abundance ratio calculated by the above calculation and the change in the PFAS compound abundance ratio compared to Example 1 or Example 10 are shown in Tables 4 and 5.

[0383] [Environmental Regulations] Of the resist compositions obtained in the present examples and comparative examples, resist compositions that did not contain a PFAS compound as the acid generator component (B) were marked with an "O" and resist compositions that contained a PFAS compound as the acid generator component (B) were marked with an "X". These are shown in Tables 4 and 5.

[0384]

[0385]

[0386] As shown in Tables 4 and 5, it was confirmed that the resist compositions of the examples provided good sensitivity in the formation of resist patterns and also reduced the environmental impact.

[0387] On the other hand, as shown in Tables 4 and 5, when the resist compositions of the comparative examples were used, either the sensitivity or the reduction in environmental impact was poor during the formation of the resist pattern.

Claims

1. A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising: a resin component (A1) whose solubility in a developer changes due to the action of the acid; and an acid generator component (B) that generates acid upon exposure, wherein the resin component (A1) has a structural unit (a0) represented by the following general formula (a0-m), and the acid generator component (B) contains a compound (B0) represented by the following general formula (b0): [In the formula, Ra 0 is a lactone-containing cyclic group, —SO ２ R represents at least one cyclic group selected from the group consisting of -containing cyclic groups and carbonate-containing cyclic groups. ０ represents an alkyl group having 1 to 5 carbon atoms or a hydrogen atom. 0 represents a divalent hydrocarbon group which may have an ether bond. ａ0 is an integer from 0 to 2. [In the formula, Ar represents an aromatic ring. ０ represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. ０ represents a divalent linking group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０ represents an organic group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０ represents an organic group. n01 is an integer of 1 or more as long as the valence allows. n02 is an integer of 0 or more as long as the valence allows. When n01 is an integer of 2 or more, a plurality of Rf ０ When n02 is an integer of 2 or more, a plurality of Rb ０ may be the same or different, m is an integer of 1 or more, and M ｍ＋ represents an m-valent cation, where Rf ０ , Rb ０ , and M ｍ＋ does not include a trifluoromethyl group (except when it results in a structure represented by the following general formula (np1)) and a difluoromethylene group (except when it results in a structure represented by the following general formula (np2) or (np3)). [In the formula, X １ Ha-OR １ , -N(R ２ ) R １ or -N(R １ ) ２ represents. ２ represents a methyl group, a monovalent aromatic hydrocarbon group which may have a substituent, -OR ３ , -SR ３ , or -NR ３ R ４ represents. ３ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, a carbonyl group, -OR １ , -SR １ , -N(R ２ ) R １ or -N(R １ ) ２ Represents R １ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, or a carbonyl group. ２ , R ３ , and R ４ each independently represents a hydrogen atom, a methyl group, or a monovalent aromatic hydrocarbon group which may have a substituent.

2. Ra in the general formula (a0-m) 0 is a lactone-containing cyclic group, or —SO ２ 2. The resist composition according to claim 1, wherein the compound is a -containing cyclic group.

3. Rf in the general formula (b0) ０ 3. The resist composition according to claim 1, wherein is a fluorine atom.

4. L in the general formula (b0) ０ is a divalent linking group containing —C(═O)—O— or a divalent linking group containing —O—C(═O)—, and Yb ０ 3. The resist composition according to claim 1, wherein is a cyclic group.

5. Yb in the general formula (b0) ０ 5. The resist composition according to claim 4, wherein is an alicyclic group which may have a substituent.

6. The resist composition according to claim 1 or 2, wherein the compound (B0) is a compound represented by the following general formula (b0'): [wherein, Rf ０１ represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. ０１ represents a divalent linking group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０１ represents an organic group consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, sulfur atoms, oxygen atoms, and nitrogen atoms. ０１ represents an organic group. n011 is an integer of 1 or more, n021 is an integer of 0 or more, and n011 + n022 ≦ 4. When n011 is an integer of 2 or more, a plurality of Rf ０１ When n021 is an integer of 2 or more, a plurality of Rb ０１ may be the same or different, m is an integer of 1 or more, and M ｍ＋ represents an m-valent cation, where Rf ０１ , Rb ０１ , and M ｍ＋ does not include a trifluoromethyl group (except when it results in a structure represented by the following general formula (np1)) and a difluoromethylene group (except when it results in a structure represented by the following general formula (np2) or (np3)). [In the formula, X １ Ha-OR １ , -N(R ２ ) R １ or -N(R １ ) ２ represents. ２ represents a methyl group, a monovalent aromatic hydrocarbon group which may have a substituent, -OR ３ , -SR ３ , or -NR ３ R ４ represents. ３ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, a carbonyl group, -OR １ , -SR １ , -N(R ２ ) R １ or -N(R １ ) ２ Represents R １ represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, or a carbonyl group. ２ , R ３ , and R ４ each independently represents a hydrogen atom, a methyl group, or a monovalent aromatic hydrocarbon group which may have a substituent.

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

8. The method for forming a resist pattern according to claim 7, further comprising the step of forming a topcoat layer between the step of forming the resist film and the step of exposing the resist film.

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