Resist composition, resist pattern formation method, compound, chain-transfer agent, and polymer

Abstract

A resist composition comprising a resin component, the solubility of which to a developer changes by the action of an acid, wherein the resin component contains a polymer that has, at at least one terminal of the main chain, a group represented by general formula (i-1) (in the formula, Xa1 represents an alkylene group, Rpg1, Rpg2, and Rpg3 each independently represent a hydrocarbon group optionally having a substituent, and Rpg2 and Rpg3 are optionally bonded to each other to form a ring).

Description

Resist compositions, resist pattern formation methods, compounds, chain transfer agents, and polymers

[0001] The present invention relates to a resist composition, a resist pattern formation method, a compound, a chain transfer agent, and a polymer. This application claims priority under Japanese Patent Application No. 2025-009060, filed in Japan on January 22, 2025, the contents of which are incorporated herein by reference.

[0002] In recent years, advances in lithography technology have led to rapid miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display elements. Generally, miniaturization is achieved by shortening the wavelength (increasing the energy) of the exposure light source.

[0003] Resist materials are required to possess lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns of fine dimensions. Conventionally, chemically amplified resist compositions have been used as resist materials that satisfy these requirements, containing a base component whose solubility in a developer solution changes due to the action of an acid, and an acid generator component that generates acid upon exposure. In chemically amplified resist compositions, polymer compounds having multiple constituent units are generally used as the base component to improve lithography characteristics and other properties.

[0004] The polymer compounds used in the aforementioned base components are typically produced by radical polymerization of monomers having various functions. Azo polymerization initiators such as azobisisobutyronitrile (AIBN) are generally used as polymerization initiators in radical polymerization, and a partial structure of the azo polymerization initiator is introduced at the ends of the produced polymer compounds. A polymer compound in which a tertiary ester-type acid-dissociable group is introduced at the end of the main chain as the partial structure, and a resist composition containing the same have been disclosed (see, for example, Patent Document 1).

[0005] Japanese Patent Publication No. 2014-153686

[0006] As resist patterns become smaller, for example, in EUV (extreme ultraviolet) and EB (electron beam) lithography, the goal is to form fine patterns of several tens of nanometers. With this miniaturization of resist patterns, the challenge is to improve lithographic properties such as roughness while maintaining good sensitivity. However, these lithographic properties are in a trade-off relationship, and improving one property tends to degrade the other. In resist compositions, it is required to improve both sensitivity and roughness without creating a trade-off between them. Furthermore, the long-term stability of the resist composition is also required.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a resist composition that has good sensitivity, roughness, and temporal stability in the formation of a resist pattern, a method for forming a resist pattern using the resist composition, and a compound, chain transfer agent, and polymer suitable for the resist composition.

[0008] 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 acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition containing a resin component whose solubility in a developer changes due to the action of the acid, wherein the resin component contains a polymer having a group represented by the following general formula (i-1) at at least one end of the main chain.

[0009] [wherein Xa １ It is an alkylene group. (Rpg) １ RPG ２ and RPG ３ These are each independently hydrocarbon groups that may have substituents. ２ and RPG ３ These may be joined together to form a ring.

[0010] A second aspect of the present invention is a resist pattern forming method including a step of forming a resist film on a support using the resist composition according to the first aspect, a step of exposing the resist film, and a step of developing the resist film after the exposure to form a resist pattern.

[0011] A third aspect of the present invention is a compound represented by the following general formula (I).

[0012] [In the formula, Xa １ is an alkylene group. Rpg １ , Rpg ２ and Rpg ３ are each independently a hydrocarbon group which may have a substituent. Rpg ２ and Rpg ３ may be bonded to each other to form a ring. ]

[0013] A fourth aspect of the present invention is a chain transfer agent containing the compound according to the third aspect.

[0014] A fifth aspect of the present invention is a polymer having a group represented by the following general formula (i-1) at at least one end of the main chain.

[0015] [In the formula, Xa １ is an alkylene group. Rpg １ , Rpg ２ and Rpg ３ are each independently a hydrocarbon group which may have a substituent. Rpg ２ and Rpg ３ may be bonded to each other to form a ring. ]

[0016] According to the present invention, in the formation of a resist pattern, it is possible to provide a resist composition having good sensitivity, roughness and stability over time, a resist pattern forming method using the resist composition, a compound suitable for the resist composition, a chain transfer agent and a polymer.

[0017] In this specification and in the claims, “aliphatic” is defined as a concept relative to aromatic, meaning a group, compound, etc. that does not possess aromaticity. Unless otherwise specified, “alkyl group” includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups. “Halogen atom” includes fluorine, chlorine, bromine, and iodine atoms. “Constituent unit” means a monomer unit (monomer unit) that constitutes a polymer compound (resin, polymer, copolymer). When it is stated that “may have substituents,” this refers to the substitution of a hydrogen atom (-H) with a monovalent group, or a methylene group (-CH ２ This includes both cases where the negative (-) is substituted with a divalent group. "Exposure" is a concept that includes all forms of radiation irradiation.

[0018] An "acid-degradable group" is a group that is acid-degradable, meaning that at least some of the bonds in its structure can be cleaved by the action of an acid. Examples of acid-degradable groups whose polarity increases by the action of an acid include groups that decompose to produce polar groups by the action of an acid. Examples of polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO4). ３ Examples include H). More specifically, examples of acid-degradable groups include groups in which the polar group is protected by an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0019] An "acid-dissociable group" refers to both (i) a group that has acid-dissociability, in which the bond between the acid-dissociable group and an adjacent atom can be cleaved by the action of an acid, and (ii) a group in which, after some of the bonds are cleaved by the action of an acid, a decarboxylation reaction occurs, further cleaving of the bond between the acid-dissociable group and an adjacent atom. The acid-dissociable group constituting the acid-degradable group must be a group with lower polarity than the polar group generated by the dissociation of the acid-dissociable group. As a result, when the acid-dissociable group dissociates by the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, increasing the polarity. Consequently, the overall polarity of component (A1) increases. This increase in polarity relatively changes the solubility in the developer; solubility increases when the developer is an alkaline developer, and decreases when the developer is an organic developer.

[0020] "Base material components" are organic compounds that have film-forming ability. Organic compounds used as base material components are broadly classified into nonpolymers and polymers. Nonpolymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, "low molecular weight compounds" refer to nonpolymers with a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, "resins," "high molecular weight compounds," or "polymers" refer to polymers with a molecular weight of 1000 or more. The molecular weight of polymers shall be the weight-average molecular weight on a polystyrene basis calculated by GPC (gel permeation chromatography).

[0021] "Induced structural unit" means a structural unit formed by the cleavage of multiple bonds between carbon atoms, such as an ethylenic double bond. "Acrylic acid ester" may have a hydrogen atom bonded to the α-carbon atom substituted with a substituent. A substituent (R) that substitutes the hydrogen atom bonded to the α-carbon atom. αｘ ) is an atom or group other than a hydrogen atom. Also, substituents (R αｘ Itaconic acid diesters in which the substituent (R) is substituted with substituents containing an ester bond, or substituents (R αｘThis also includes α-hydroxyacrylic esters in which the α-carbon atom is substituted with a hydroxyalkyl group or a group that modifies its hydroxyl group. Unless otherwise specified, the α-carbon atom of an acrylic acid ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom is substituted with a substituent may be called an α-substituted acrylic acid ester.

[0022] The term "derivative" is defined as a compound in which the α-position hydrogen atom of the target compound is substituted with another substituent such as an alkyl group or alkyl halide, and includes derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound, which may have the α-position hydrogen atom substituted with a substituent, is substituted with an organic group; and those in which a substituent other than a hydroxyl group is bonded to the target compound, which may have the α-position hydrogen atom substituted with a substituent. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. Examples of substituents that substitute the α-position hydrogen atom of hydroxystyrene include R αｘ Similar examples include the above.

[0023] In this specification and in the claims, depending on the structure represented by the chemical formula, an asymmetric carbon may be present, and enantioisomers and diastereoisomers may exist. In such cases, a single chemical formula will represent all of these isomers. These isomers may be used individually or as a mixture.

[0024] (First Embodiment: Resist Composition) One embodiment of a resist composition generates acid upon exposure and changes in solubility in a developer due to the action of the acid. Such a 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 the acid. Component (A) contains a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes due to the action of the acid, and the resin component (A1) contains a polymer having a specific group (a group represented by general formula (i-1)) that includes an acid-dissociable group.

[0025] In the resist composition of this embodiment, component (A) may generate acid upon exposure, or an additive component formulated separately from component (A) may generate acid upon exposure. Specifically, the resist composition of this embodiment may further contain (1) an acid-generating component (B) that generates acid upon exposure (hereinafter referred to as "component (B)"); (2) component (A) may be a component that generates acid upon exposure; or (3) component (A) may be a component that generates acid upon exposure and further contains component (B). That is, in the cases of (2) and (3) above, component (A) is a "base component that generates acid upon exposure and whose solubility in the developer solution changes due to the action of the acid." When component (A) is a base component that generates acid upon exposure and whose solubility in the developer solution changes due to the action of the acid, it is preferable that component (A1), described later, is a resin that generates acid upon exposure and whose solubility in the developer solution changes due to the action of the acid. As such a resin, a polymer compound having a constituent unit that generates acid upon exposure can be used. As the constituent unit that generates acid upon exposure, the constituent unit (a5) described later may be used.

[0026] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, for example, acid is generated from component (B) in the exposed areas of the resist film, and the solubility of component (A) in the developer changes due to the action of this acid, while the solubility of component (A) in the developer does not change in the unexposed areas of the resist film. As a result, a difference in solubility in the developer occurs between the exposed and unexposed areas. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed areas of the resist film are dissolved and removed to form a positive type resist pattern, and if the resist composition is negative type, the unexposed areas of the resist film are dissolved and removed to form a negative type resist pattern.

[0027] The resist composition of this embodiment may be a positive-type resist composition or a negative-type resist composition. Furthermore, the resist composition of this embodiment may be for an alkaline development process that uses an alkaline developer for the development process during resist pattern formation, or for a solvent development process that uses a developer containing an organic solvent (organic developer) for the development process.

[0028] <Substrate Component (A)> In the resist composition of this embodiment, component (A) includes at least the resin component (A1). That is, component (A1) includes at least a resin component that has a polymer whose solubility in the developer changes due to the action of an acid and which has a group represented by general formula (i-1) at at least one end of the main chain. By using such a component (A1), the polarity of the substrate component changes before and after exposure, so that good development contrast can be obtained not only in the alkaline development process but also in the solvent development process. In addition, roughness can be reduced in the formation of the resist pattern, and the time-dependent stability of the resist composition can be improved.

[0029] Component (A) may be at least one of other polymer compounds and low molecular weight compounds in combination with component (A1). The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of component (A). When the proportion is 25% by mass or more, the above-mentioned effects, good lithography characteristics, and resist pattern shape are easily obtained.

[0030] - About component (A1) Component (A1) is a resin component whose solubility in the developer changes due to the action of an acid. In addition, component (A1) includes a polymer having a group represented by the general formula (i-1) described below at at least one end of the main chain (hereinafter also referred to as "component (A1-0)"). In the resist composition of this embodiment, component (A1) may consist only of component (A1-0), or it may be a combination of component (A1-0) and a polymer whose solubility in the developer changes due to the action of an acid (excluding those corresponding to component (A1-0); hereinafter also referred to as "component (A2)").

[0031] The (A1-0) component is a polymer having a group represented by the following general formula (i-1) (hereinafter also referred to as the "terminal group (i-1)") at at least one end of the main chain. The (A1-0) component is preferably one having a constituent unit (a1) that contains an acid-degradable group whose polarity increases upon the action of an acid. In addition to the constituent unit (a1), the (A1-0) component may also have other constituent units as needed.

[0032] ≪Terminal group (i-1)≫ The terminal group (i-1) is represented by the following general formula (i-1).

[0033] [wherein Xa １ It is an alkylene group. (Rpg) １ RPG ２ and RPG ３ These are each independently hydrocarbon groups that may have substituents. ２ and RPG ３ These may be joined together to form a ring.

[0034] In the above formula (i-1), Xa １ Examples of alkylene groups include linear or branched alkylene groups. Linear alkylene groups are preferably those having 1 to 5 carbon atoms, more preferably those having 1 to 3 carbon atoms, and even more preferably those having 1 or 2 carbon atoms. Specifically, methylene groups [-CH] ２ -], ethylene group [- (CH ２ ) ２-], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ Examples include -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 - Alkyl methylene 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 - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２- Examples thereof include alkylalkylene groups such as an alkyltetramethylene group. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0035] Among them, Xa １ As the alkylene group in, an alkylene group having 1 to 5 carbon atoms is preferable, an alkylene group having 1 to 3 carbon atoms is more preferable, and an alkylene group having 1 or 2 carbon atoms is even more preferable. <000 (

[0036] In the formula (i-1), Rpg １ , Rpg ２ And Rpg ３ Examples of the hydrocarbon group in include a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group.

[0037] 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. Specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. can be mentioned. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

[0038] The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc. can be mentioned, and an isopropyl group is preferable.

[0039] The linear or cyclic alkenyl group is preferably an alkenyl group having 2 to 10 carbon atoms.

[0040] Rpg １ , Rpg ２ And Rpg ３The cyclic hydrocarbon group in [5.2.1.0] may be an aliphatic hydrocarbon group or an aromatic group, and may be a polycyclic or monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. As a polycyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ Examples include decane and tetracyclododecane.

[0041] RPG １ RPG ２ and RPG ３ When a cyclic hydrocarbon group in a compound becomes an aromatic group, the aromatic group is a 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, and may have substituents that substitute for hydrogen atoms on the aromatic ring. Examples of aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles in which part of the ring skeleton is composed of heteroatoms. The number of carbon atoms in the aromatic hydrocarbon ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, phenanthrene, and the like. The number of carbon atoms in the aromatic heterocycle is preferably 4 to 30, more preferably 4 to 20, even more preferably 4 to 15, and particularly preferably 4 to 12. However, the number of carbon atoms does not include the number of carbon atoms in substituents that substitute for hydrogen atoms in the aromatic heterocycle. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, nitrogen atoms, etc. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Rpg １ RPG ２and Rpg ３ Specific examples of the aromatic group in [Rp] include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or the aromatic heterocyclic ring (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group in which one hydrogen atom of the aromatic hydrocarbon ring or the aromatic heterocyclic ring is substituted with an alkylene group (such as arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or the aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0042] Rpg １ 、Rpg ２ and Rpg ３ The cyclic hydrocarbon group in [Rp], [Rpg], and [Rpg] may have a substituent. Examples of this substituent include, for example, -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 also collectively referred to as "Ra ｘ５ ").), a halogen atom, a halogenated alkyl group, etc. Here, R Ｐ１ is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R Ｐ２ is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, R Ｐ１ and R Ｐ２Some or all of the hydrogen atoms in the chain-like saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the substituents individually, or it may have one or more of each of the substituents. Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl, tricyclo[5.2.1.02,6]decanyl, tricyclo[3.3.1.13,7]decanyl, tetracyclo[6.2.1.13,6.02,7]dodecanyl, and adamantyl groups. Examples of monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring, such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0043] RPG ２ and RPG ３ However, when they bond to each other to form a ring, in formula (i-1), -C(Rpg １ ) (RPG ２ ) (RPG ３ The group represented by the following general formula (a1-r2-1), the group represented by the following general formula (a1-r2-2), and the group represented by the following general formula (a1-r2-3) are preferred. On the other hand, Rpg ２ and RPG ３ However, if they are independent hydrocarbon groups that are not bonded to each other, in formula (i-1), -C(Rpg １ ) (RPG ２ ) (RPG ３ The group is preferably represented by the following general formula (a1-r2-4).

[0044] [In formula (a1-r2-1), Ra'１０ This represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups. １１ Ra' １０ This indicates a group that forms an aliphatic cyclic group together with the bonded carbon atom. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that 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 Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. Ra １０１ ~Ra １０３ Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ is an aromatic group which may have substituents. In formula (a1-r2-4), Ra' １２ and Ra' １３ Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' １４ This is a hydrocarbon group that may have substituents. * indicates a bond.

[0045] In the above formula (a1 - r2 - 1), Ra' １０ This is a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups.

[0046] Ra' １０ In this context, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. １０ In this, the branched alkyl group is the Ra' ３ Similar examples include the above.

[0047] Ra' １０ In this context, 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. Also, some of the carbon atoms constituting the alkyl group (such as a methylene group) may be substituted with a heteroatom-containing group. Examples of heteroatoms here include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-NH-, -NH-, -S-, and -S(=O). ２ -, -S (=O) ２ Examples include -O-, etc.

[0048] In formula (a1-r2-1), Ra' １１ (Ra' １０ The aliphatic cyclic group formed with the bonded carbon atom is Rpg in formula (i-1). １ The aliphatic hydrocarbon groups (alicyclic hydrocarbon groups) listed above, which are monocyclic or polycyclic groups, are preferred. Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl groups and cyclohexyl groups are more preferred.

[0049] In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya is Rpg in formula (i-1). １ Examples include a cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) from which one or more hydrogen atoms have been further removed. The cyclic hydrocarbon group formed by Xa together with Ya may have substituents. Examples of such substituents include the above-mentioned Rpg １ Examples include substituents similar to those that may be present on the cyclic hydrocarbon group in formula (a1-r2-2). １０１ ~Ra １０３ Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. １０１ ~Ra １０３Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; bicyclo[2.2.2]octanyl, tricyclo[5.2.1.0 ２，６ ] Decanyl group, tricyclo[3.3.1.1 ３，７ ] Decanyl group, tetracyclo[6.2.1.1 ３，６ . 0 ２，７ Examples include polycyclic aliphatic saturated hydrocarbon groups such as dodecanyl groups and adamantyl groups. １０１ ~Ra １０３ Of these, from the viewpoint of ease of synthesis, hydrogen atoms and monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms are preferred, and among these, hydrogen atoms, methyl groups, and ethyl groups are more preferred, with hydrogen atoms being particularly preferred.

[0050] The above Ra １０１ ~Ra １０３ Examples of substituents on a chain-like saturated hydrocarbon group or an aliphatic cyclic saturated hydrocarbon group represented by the above Ra ｘ５ Similar bases can be cited.

[0051] Ra １０１ ~Ra １０３ Groups containing a carbon-carbon double bond formed by the bonding of two or more carbon atoms to each other to form a cyclic structure include, for example, cyclopentenyl group, cyclohexenyl group, methylcyclopentenyl group, methylcyclohexenyl group, cyclopentylideneethenyl group, and cyclohexyllideneethenyl group. Among these, cyclopentenyl group, cyclohexenyl group, and cyclopentylideneethenyl group are preferred from the viewpoint of ease of synthesis.

[0052] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Rpg in formula (i-1). １ The groups listed as aliphatic hydrocarbon groups that are monocyclic or polycyclic are preferred. In formula (a1-r2-3), Ra １０４Aromatic groups in this context include groups obtained by removing one or more hydrogen atoms from an aromatic ring having 5 to 30 carbon atoms. Among them, Ra １０４ Preferably, the group is an aromatic hydrocarbon ring having 6 to 15 carbon atoms from which one or more hydrogen atoms have been removed, or an aromatic heterocycle having 4 to 15 carbon atoms from which one or more hydrogen atoms have been removed. More preferably, the group is a benzene, naphthalene, anthracene, phenanthrene, furan, pyrrole, or thiophene from which one or more hydrogen atoms have been removed. Even more preferably, the group is a benzene, naphthalene, anthracene, or thiophene from which one or more hydrogen atoms have been removed. Particularly preferred is a benzene from which one or more hydrogen atoms have been removed, and most preferably, the group is a benzene from which one or more hydrogen atoms have been removed.

[0053] Ra in equation (a1-r2-3) １０４ Examples of substituents that may be present include methyl groups, ethyl groups, propyl groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups (such as methoxy groups, ethoxy groups, propoxy groups, butoxy groups, etc.), and alkyloxycarbonyl groups.

[0054] In formula (a1-r2-4), Ra' １２ and Ra' １３ Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. １２ and Ra' １３ In this, the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms is the above Ra １０１ ~Ra １０３ Examples include monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' １２ and Ra' １３ Among these, alkyl groups having 1 to 5 carbon atoms are preferred, alkyl groups having 1 to 5 carbon atoms are more preferred, methyl groups and ethyl groups are even more preferred, and methyl groups are particularly preferred. １２ and Ra' １３ When a chain-like saturated hydrocarbon group represented by is substituted, the substituent may be, for example, the above-mentioned Ra ｘ５ Similar bases can be cited.

[0055] In formula (a1-r2-4), Ra' １４ Ra' is a hydrocarbon group that may have substituents. １４ Examples of hydrocarbon groups in this context include linear or branched alkyl groups, or cyclic hydrocarbon groups.

[0056] Ra' １４ The linear alkyl group in this compound preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0057] Ra' １４ The branched alkyl group in the compound preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0058] Ra' １４ When the hydrocarbon group is cyclic, it may be an aliphatic hydrocarbon group or an aromatic group, and may be a polycyclic or monocyclic group. A preferred monocyclic aliphatic hydrocarbon group is one obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic aliphatic hydrocarbon group is one obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0059] Ra' １４ As for aromatic groups in this case, Ra １０４Examples include those similar to aromatic groups in [the text]. Among them, Ra' １４ The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms with one or more hydrogen atoms removed, or an aromatic heterocycle having 4 to 15 carbon atoms with one or more hydrogen atoms removed, more preferably a group from benzene, naphthalene, anthracene, phenanthrene, furan, pyrrole, or thiophene with one or more hydrogen atoms removed, even more preferably a group from benzene, naphthalene, anthracene, or thiophene with one or more hydrogen atoms removed, particularly preferably a group from naphthalene or anthracene with one or more hydrogen atoms removed, and most preferably a group from naphthalene with one or more hydrogen atoms removed. １４ A substituent that may be present is Ra １０４ Examples of substituents that may be present include those similar to those that the molecule may have.

[0060] Ra' in equation (a1-r2-4) １４ When is a naphthyl group, the position where it bonds to the tertiary carbon atom in formula (a1-r2-4) may be either position 1 or position 2 of the naphthyl group. １４ If is an anthyl group, the position of the bond with the tertiary carbon atom in formula (a1-r2-4) may be position 1, 2, or 9 of the anthyl group.

[0061] Specific examples of the group represented by the above formula (a1-r2-1) are given below.

[0062]

[0063]

[0064]

[0065] Specific examples of the group represented by the above formula (a1-r2-2) are given below.

[0066]

[0067]

[0068]

[0069] Specific examples of the group represented by the above formula (a1-r2-3) are given below.

[0070]

[0071] Specific examples of the group represented by the above formula (a1-r2-4) are given below.

[0072]

[0073] In formula (i-1), -C(Rpg １ ) (RPG ２ ) (RPG ３ The group is preferably the group represented by the general formula (a1-r2-1), the group represented by the general formula (a1-r2-2), the group represented by the general formula (a1-r2-3), or the group represented by the general formula (a1-r2-4), and from the viewpoint of sensitivity and LWR, the group represented by the general formula (a1-r2-2) or the group represented by the general formula (a1-r2-3) is more preferred, and the group represented by the general formula (a1-r2-2) is even more preferred.

[0074] The (A1-0) component may be any polymer having an end group (i-1), and the components other than the end group (i-1) can be the same as those of a resin component (base resin) commonly used as a substrate component for chemically amplified resists. The (A1-0) component is preferably one having a constituent unit (a1) that contains an acid-degradable group whose polarity increases with the action of an acid. A preferred (A1-0) component may also have other constituent units as needed, in addition to the aforementioned constituent unit (a1).

[0075] ≪Constituent Unit (a1)≫ Constituent unit (a1) is a constituent unit that contains an acid-degradable group whose polarity increases due to the action of an acid.

[0076] Examples of acid-dissociable groups include those previously proposed as acid-dissociable groups for base resins used in chemically amplified resist compositions. Specifically, examples of acid-dissociable groups proposed for base resins used in chemically amplified resist compositions include the following: "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," "tertiary alkyloxycarbonyl acid-dissociable groups," and "secondary alkyloxycarbonyl acid-dissociable groups."

[0077] Acetal-type acid-dissociating group: Among the polar groups, an example of an acid-dissociating group that protects a carboxyl group or a hydroxyl group is the acid-dissociating group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociating group").

[0078] [In the formula, Ra' １ , Ra' ２ Ra' is a hydrogen atom or an alkyl group. ３ is a hydrocarbon group, Ra' ３ Ra' １ , Ra' ２ It may combine with any of the following to form a ring.

[0079] In formula (a1-r-1), Ra' １ and Ra' ２ Preferably, at least one of them is a hydrogen atom, and more preferably, both are hydrogen atoms. １ Or Ra' ２ If the alkyl group is an alkyl group, the alkyl group can be the same as those listed in the description of the α-substituted acrylic acid ester above as substituents that may be bonded to the carbon atom at the α position, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups are preferred. More specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc., with methyl group or ethyl group being more preferred, and methyl group being particularly preferred.

[0080] In formula (a1-r-1), Ra' ３Examples of hydrocarbon groups include linear or branched alkyl groups, or cyclic hydrocarbon groups. 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. Specifically, examples include methyl groups, ethyl groups, n-propyl groups, n-butyl groups, and n-pentyl groups. Among these, methyl groups, ethyl groups, or n-butyl groups are preferred, and methyl groups or ethyl groups are more preferred.

[0081] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0082] Ra' ３ When the hydrocarbon group is cyclic, it may be an aliphatic hydrocarbon group or an aromatic group, and may be a polycyclic or monocyclic group. A preferred monocyclic aliphatic hydrocarbon group is one obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic aliphatic hydrocarbon group is one obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0083] Ra' ３ When a cyclic hydrocarbon group becomes an aromatic group, the aromatic 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, and may have substituents that substitute for the hydrogen atoms of the aromatic ring. Examples of aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles.

[0084] The aromatic hydrocarbon ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this carbon atom count does not include the carbon atoms in substituents that substitute for hydrogen atoms in the aromatic hydrocarbon ring. Specific examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, and phenanthrene.

[0085] The number of carbon atoms in the aromatic heterocycle is preferably 4 to 30, more preferably 4 to 20, even more preferably 4 to 15, and particularly preferably 4 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents that substitute for hydrogen atoms in the aromatic heterocycle. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, nitrogen atoms, etc. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

[0086] Ra' ３ Specific examples of aromatic groups in this context include: a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or the aromatic heterocycle (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or the aromatic heterocycle is substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or the aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0087] Ra' ３ The cyclic hydrocarbon group in may have substituents. Examples of substituents 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 (These substituents are collectively referred to as "Ra ｘ５ It is also called "." ) are some examples. Here, R Ｐ１ This is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R Ｐ２ R is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, R Ｐ１ and R Ｐ２ Some or all of the hydrogen atoms in the chain-like saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the substituents individually, or it may have one or more of each of the substituents. Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.0 ２，６ ] Decanyl group, tricyclo[3.3.1.1 ３，７ ] Decanyl group, tetracyclo[6.2.1.13,6.0 ２，７ Examples include polycyclic aliphatic saturated hydrocarbon groups such as dodecanyl groups and adamantyl groups. Examples of monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring, such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0088] Ra' ３ But, Ra' １ , Ra' ２ When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0089] Tertiary alkyl ester type acid-dissociating groups: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-2). Of the acid-dissociating groups represented by the following formula (a1-r-2), those composed of alkyl groups may hereafter be referred to as "tertiary alkyl ester type acid-dissociating groups" for convenience.

[0090] [In the formula, Ra' ４ ~Ra' ６ Each of these is a hydrocarbon group, Ra' ５ , Ra' ６ They may be joined to each other to form a ring.

[0091] Ra' ４ Examples of hydrocarbon groups include linear or branched alkyl groups, linear or cyclic alkenyl groups, or cyclic hydrocarbon groups. ４ In the above, linear or branched alkyl groups, cyclic hydrocarbon groups (monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, aromatic groups) are defined as Ra' ３ Similar examples include Ra' ４ The linear or cyclic alkenyl group in Ra' is preferably an alkenyl group having 2 to 10 carbon atoms. ５ , Ra' ６ The hydrocarbon group is the Ra' mentioned above. ３ Similar examples include the above.

[0092] Ra' ５ and Ra' ６When these groups bond to each other to form a ring, the group represented by the general formula (a1-r2-1), the group represented by the general formula (a1-r2-2), and the group represented by the general formula (a1-r2-3) are preferred. On the other hand, Ra' ４ ~Ra' ６ When these are independent hydrocarbon groups that are not bonded to each other, the group represented by the general formula (a1-r2-4) is preferably mentioned.

[0093] Tertiary alkyloxycarbonylic acid dissociable group: Among the polar groups, an example of an acid-dissociable group that protects a hydroxyl group is the acid-dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as a "tertiary alkyloxycarbonylic acid dissociable group" for convenience).

[0094] [In the formula, Ra' ７ ~Ra' ９ These are each alkyl groups.

[0095] In formula (a1-r-3), Ra' ７ ~Ra' ９ Each alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Furthermore, 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.

[0096] Secondary alkyl ester type acid-dissociating groups: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-4).

[0097] [In the formula, Ra' １０ Ra' is a hydrocarbon group. １１ａ and Ra' １１ｂ Each of these is independently a hydrogen atom, a halogen atom, or an alkyl group. Ra' １２ Ra' is a hydrogen atom or a hydrocarbon group. １０ and Ra' １１ａ Or Ra' １１ｂ These may be joined together to form a ring. １１ａ Or Ra'１１ｂ And, Ra' １２ These elements may be joined together to form a ring.

[0098] In the formula, Ra' １０ and Ra' １２ The hydrocarbon group in this is the Ra' group. ３ Similar examples can be given. In the formula, Ra' １１ａ and Ra' １１ｂ The alkyl group in is the Ra' １ Examples include alkyl groups similar to those in the formula. In the formula, Ra' １０ and Ra' １２ The hydrocarbon group in, and Ra' １１ａ and Ra' １１ｂ The alkyl group in may have substituents. For example, the above-mentioned Ra ｘ５ These are some examples.

[0099] Ra' １０ and Ra' １１ａ Or Ra' １１ｂ These elements may bond to each other to form a ring. This ring may be polycyclic or monocyclic, and may be alicyclic or aromatic. The alicyclic and aromatic rings may contain heteroatoms.

[0100] Ra' １０ and Ra' １１ａ Or Ra' １１ｂ The rings formed by the bonding of these elements are preferably monocycloalkenes, rings in which some of the carbon atoms of a monocycloalken are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), monocycloalkadienes, cycloalkenes having 3 to 6 carbon atoms, and cyclopentene or cyclohexene.

[0101] Ra' １０ and Ra' １１ａ Or Ra' １１ｂ The ring formed by the bonding of these elements may be a fused ring. Specific examples of such fused rings include indane.

[0102] Ra' １０ and Ra' １１ａ Or Ra' １１ｂThe ring formed by the bonding of these elements may have substituents. For example, the above-mentioned Ra ｘ５ These are some examples.

[0103] Ra' １１ａ Or Ra' １１ｂ And, Ra' １２ These elements may be bonded together to form a ring, and the ring may be Ra' １０ and Ra' １１ａ Or Ra' １１ｂ Examples include rings formed by the bonding of these elements together.

[0104] Specific examples of the group represented by the above formula (a1-r-4) are given below.

[0105]

[0106] Examples of the constituent unit (a1) include a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent, a constituent unit derived from acrylamide, a constituent unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a portion of the hydrogen atoms in the hydroxyl group of the constituent unit is protected by a substituent containing the acid-degradable group, and a constituent unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative in which at least a portion of the hydrogen atoms in the -C(=O)-OH group is protected by a substituent containing the acid-degradable group.

[0107] As for the constituent unit (a1), among the above, a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent is preferred. Preferred specific examples of such constituent unit (a1) include the constituent units represented by the following general formulas (a1-1), (a1-2), or (a1-3).

[0108] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Va １ n is a divalent hydrocarbon group which may have an ether bond. ａ１ is an integer between 0 and 2. １This is an acid-dissociable group represented by the general formula (a1-r-1), (a1-r-2), or (a1-r-4) above. Wa １ han ａ２ It is a +1 valent hydrocarbon group. ａ２ Ra is an integer between 1 and 3. ２ This is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-3) above. ００１ It is a single bond or a divalent linking group. ０１ It is a single bond or a divalent linking group. Rax ０１ Rz is an acid-dissociable group represented by the general formula (a1-r-1), (a1-r-2), or (a1-r-4) above. ０１ [where n is an alkyl group, halogen atom, alkyl halide, hydroxyl group, or alkoxy group; q is an integer between 0 and 3; n is a non-negative integer, where n ≤ q × 2 + 4]

[0109] In formulas (a1-1) to (a1-3), the C1-C5 alkyl group of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. The C1-C5 halogenated alkyl group is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Fluorine atoms are particularly preferred as the halogen atoms. R is preferably a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 fluorinated alkyl group, with hydrogen atoms or methyl groups being the most preferred due to their industrial availability.

[0110] In the above formula (a1-1), Va １ The divalent hydrocarbon group in this expression may be an aliphatic hydrocarbon group or an aromatic group.

[0111] Va １The aliphatic hydrocarbon group as the divalent hydrocarbon group in this product may be saturated or unsaturated, but is usually preferred to be saturated. More specifically, examples of such aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0112] 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. A linear alkylene group is preferred as the linear aliphatic hydrocarbon group, 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 Examples include -]. 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. A branched alkylene group is preferred as the branched aliphatic hydrocarbon group, 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 - Alkyl methylene groups such as -CH(CH ３ )CH ２ -, -CH(CH ３ )CH(CH ３ )-,-C(CH ３ ) ２CH ２ -, -CH(CH ２ CH ３ )CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２ Examples include alkylalkylene groups such as alkyltetramethylene groups. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0113] Examples of aliphatic hydrocarbon groups containing a ring in the structure include alicyclic hydrocarbon groups (groups obtained by removing two hydrogen atoms 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 middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically examples include cyclopentane and cyclohexane. As for the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0114] Va １In this context, the aromatic group as a divalent hydrocarbon group is a group having an aromatic ring. Such an aromatic 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 substituents. Specific examples of aromatic rings in an aromatic group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which part of the ring skeleton is composed of heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specifically, examples of the aromatic group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); and a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) in which one hydrogen atom is replaced by an alkylene group (for example, a group obtained by removing one more hydrogen atom from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0115] In the above formula (a1-1), Ra １ The acid-dissociable group is preferably represented by the general formula (a1-r-2) or (a1-r-4) described above, and among these, the group represented by the general formula (a1-r2-1) or the acid-dissociable group represented by the general formula (a1-r-4) is more preferred.

[0116] In the above formula (a1-2), Wa １ (n ａ２The +1) valence hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that is a combination of a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in its structure. ａ２ The +1 valency is preferably 2 to 4 valencies, and more preferably 2 or 3 valencies. In the above formula (a1-2), Ra ２ The acid-dissociable group represented by the above general formula (a1-r-1) is preferred.

[0117] In the above formula (a1-3), Ya ００１ The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. ００１ Preferably, the alkylene group is an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group or a combination thereof, or a single bond. The number of carbon atoms in the alkylene group is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 4, and particularly preferably 1 to 3. Among these, Ya ００１ The combination of an ester bond [-C(=O)-O-, -O-C(=O)-] and a linear alkylene group is more preferable, and a single bond is even more preferable.

[0118] In the above formula (a1-3), Ya ０１ The divalent linking group in this is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have substituents, a divalent linking group which contains a heteroatom, and so on. ０１Among the above, it is preferable that the ester bond [-C(=O)-O-, -O-C(=O)-], ether bond (-O-), linear or branched alkylene group, aromatic hydrocarbon group or a combination thereof, or single bond. Among these, Ya ０１ The combination of an ester bond [-C(=O)-O-, -O-C(=O)-] and a linear alkylene group is more preferable, and a single bond is even more preferable.

[0119] In the above formula (a1-3), Rax ０１ The acid-dissociable group is preferably represented by the general formula (a1-r-2) or (a1-r-4) described above, and among these, the acid-dissociable group represented by the general formula (a1-r-2) is more preferred, and the group represented by the general formula (a1-r2-1) is even more preferred.

[0120] In the above formula (a1-3), Rz ０１ The alkyl group, alkyl halide, and alkoxy group in the above is preferably having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, even more preferably 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The alkyl group, alkyl halide, and alkoxy group may be linear or branched. Rz ０１ In this case, iodine is preferred as the halogen atom. ０１ In the alkyl halide, the halogen atom is preferably a fluorine atom, an iodine atom, or a bromine atom, with a fluorine atom being more preferred. Rz ０１ The group is preferably an alkoxy group or a hydroxyl group, with a hydroxyl group being more preferred.

[0121] In formula (a1-3), q is an integer from 0 to 3. When q is 0, it is a benzene structure; when q is 1, it is a naphthalene structure; when q is 2, it is an anthracene structure; and when q is 3, it is a tetracene structure. In formula (a1-3), n is an integer of 0 or more, preferably from 0 to 5, more preferably from 0 to 3, and even more preferably 1 or 2. When n is an integer of 2 or more, Rz is 2 or more. ０１These can be the same or different from each other. In the above formula (a1-3), n ≤ q × 2 + 4. For example, if q is 1 and the structure is naphthalene, then all six hydrogen atoms of the naphthalene are Rz ０１ It may be substituted with Ya ００１ , -Ya ０１ -C(=O)-O-Ra ０１ Base, and Rz ０１ The substitution position is not particularly limited.

[0122] The following are specific examples of constituent units (a1). In each of the following formulas, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132] In the following equations, R α Rz represents a hydrogen atom, a methyl group, or a trifluoromethyl group. Rz represents a hydrogen atom, an alkyl group, a halogen atom, an alkyl halide, a hydroxyl group, or an alkoxy group.

[0133]

[0134]

[0135]

[0136]

[0137]

[0138] The constituent unit (a1) of component (A1) may be one type or two or more types. As for the constituent unit (a1), the constituent unit represented by formula (a1-1) or the constituent unit represented by formula (a1-3) is more preferable because it is easier to improve the characteristics (sensitivity, shape, etc.) in electron beam or EUV lithography. Among these, the acid-dissociable group (Ra) is preferred because it can be made more reactive for EB or EUV applications. １ Rax ０１ Preferably, each of these groups is an acid-dissociable group represented by the above general formula (a1-r2-1), (a1-r2-3), (a1-r2-4), or (a1-r-4), and among these, it is particularly preferable to select a cyclic group.

[0139] Alternatively, the constituent unit (a1) may include a constituent unit represented by the following general formula (a1-1-1).

[0140] [In the formula, Ra １ " is an acid-dissociable group represented by the general formula (a1-r2-1), (a1-r2-3), (a1-r2-4), or (a1-r-4). * indicates a bond.

[0141] In the above formula (a1-1-1), R, Va １ and n ａ１ R, Va in the above formula (a1-1) １ and n ａ１ It is similar to that.

[0142] The acid-dissociable groups represented by the general formulas (a1-r2-1), (a1-r2-3), (a1-r2-4), or (a1-r-4) are described above. In particular, it is preferable to select those in which the acid-dissociable group is a cyclic group, as this enhances reactivity for use in EB or EUV applications.

[0143] The proportion of constituent unit (a1) in 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 70 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1). By setting the proportion of constituent unit (a1) to be above the lower limit of the above preferred range, lithography characteristics such as sensitivity, resolution, and CDU improvement are improved. On the other hand, if it is below the upper limit of the above preferred range, a balance with other constituent units can be achieved, resulting in good lithography characteristics in various aspects.

[0144] <<Other Constituent Units>> Component (A1) may have other constituent units as needed, in addition to the constituent unit (a1) described above. Examples of other constituent units include the constituent unit (a10) represented by the general formula (a10-1) described later; the constituent unit (a2) containing a lactone-containing cyclic group; the constituent unit (a5) that generates acid upon exposure; the constituent unit (a6) that has acid diffusion controllability; and the constituent unit (a8) derived from the compound represented by the general formula (a8-1) described later.

[0145] Constituent unit (a10): Constituent unit (a10) is a constituent unit represented by the following general formula (a10-1).

[0146] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Ya ｘ１ Wa is a single bond or a divalent linking group. ｘ１ n is an aromatic group. ａｘ１ [ is an integer greater than or equal to 1.]

[0147] In formula (a10-1), R is the same as R in general formula (a1-1). 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 a hydrogen atom or a methyl group is particularly preferred due to their industrial availability.

[0148] In the above formula (a10-1), Ya ｘ１ is a single bond or a divalent linking group. In the above chemical formula, Ya ｘ１The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0149] - Divalent hydrocarbon groups which may have substituents: Divalent hydrocarbon groups which may have substituents may be aliphatic hydrocarbon groups or aromatic groups.

[0150] ...Aliphatic hydrocarbon group An aliphatic hydrocarbon group means a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups that contain a ring in their structure.

[0151] ...Linear or branched aliphatic hydrocarbon group 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, 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 Examples include -]. 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. A branched alkylene group is preferred as the branched aliphatic hydrocarbon group, specifically -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ )-,-C(CH３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkyl methylene 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 - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２ Examples include alkylalkylene groups such as alkyltetramethylene groups. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0152] The linear or branched aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0153] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), which may contain substituents containing heteroatoms in their ring structure; groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group; and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. As a monocycloalkane, those having 3 to 6 carbon atoms are preferred, and specifically examples include cyclopentane and cyclohexane. As for the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, those having 7 to 12 carbon atoms are preferred, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0154] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. Preferably, the alkyl group is a C1-C5 alkyl group, more preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Preferably, the alkoxy group is a C1-C5 alkoxy group, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group, and even more preferably a methoxy group or ethoxy group. Preferably, the halogen atom is a fluorine atom. Examples of alkyl halides are groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. The cyclic aliphatic hydrocarbon group may also have some of the carbon atoms constituting its ring structure substituted with substituents containing heteroatoms. Substituents containing the heteroatom include -O-, -C(=O)-O-, -S-, and -S(=O). ２ -, -S (=O) ２ -O- is preferred.

[0155] ...The aromatic hydrocarbon group is a 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, polycyclic, or have substituents that substitute for the hydrogen atoms of the aromatic ring. Examples of aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles in which part of the ring skeleton is composed of heteroatoms.

[0156] The aromatic hydrocarbon ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this carbon atom count does not include the carbon atoms in substituents. Specific examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, and phenanthrene.

[0157] The number of carbon atoms in the aromatic heterocycle is preferably 4 to 30, more preferably 4 to 20, even more preferably 4 to 15, and particularly preferably 4 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents that substitute for hydrogen atoms in the aromatic heterocycle. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, nitrogen atoms, etc. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

[0158] The number of carbon atoms in the aromatic group is preferably 4 to 30, more preferably 4 to 20, even more preferably 4 to 15, and particularly preferably 4 to 12. Specific examples of aromatic groups include: a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or the aromatic heterocycle (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or the aromatic heterocycle (aryl group or heteroaryl group) in which one hydrogen atom is replaced by an alkylene group (e.g., a group obtained by removing one more hydrogen atom from the aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0159] The aromatic group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to the aromatic ring in the aromatic group may be substituted with a substituent. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and hydroxyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of alkoxy groups, halogen atoms, and alkyl halides used as substituents include those exemplified as substituents that substitute for hydrogen atoms in the cyclic aliphatic hydrocarbon group.

[0160] • Divalent linking groups containing heteroatoms: Examples of divalent linking groups containing heteroatoms include -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as alkyl groups or acyl groups), -S-, -S(=O) ２ -, -S (=O) ２ -O-, general formula -Y ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ -, -[Y ２１ -C (=O) -O] ｍ” -Y ２２ -, -Y ２１ -OC(=O)-Y ２２ - or - Y ２１ -S (=O) ２ -O-Y ２２ - is represented by the base [wherein Y ２１ and Y ２２Each of these is a divalent hydrocarbon group which may independently have substituents, O is an oxygen atom, and m'' is an integer from 1 to 3. For example, when the divalent linking group containing the heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)-, the H may be substituted with substituents such as alkyl groups or acyl groups. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5. General formula -Y ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ -, -[Y ２１ -C (=O) -O] ｍ” -Y ２２ -, -Y ２１ -OC(=O)-Y ２２ - or - Y ２１ -S (=O) ２ -O-Y ２２ - Middle, Y ２１ and Y ２２ Each of these is independently a divalent hydrocarbon group which may have substituents. Examples of such divalent hydrocarbon groups are those described above. ２１ Preferably, a linear aliphatic hydrocarbon group is preferred, a linear alkylene group is more preferred, a linear alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred. ２２ Preferably, the group is a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula - [Y ２１ -C (=O) -O] ｍ” -Y ２２ In the base represented by -, m'' is an integer from 1 to 3, preferably 1 or 2, and more preferably 1. That is, formula -[Y ２１ -C (=O) -O] ｍ”-Y ２２ As a base represented by -, see formula -Y ２１ -C(=O)-O-Y ２２ Groups represented by - are particularly preferred. Among them, the group represented by formula - (CH ２ ) ａ’ -C(=O)-O-(CH ２ ) ｂ’ A base represented by - is preferred. In the formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0161] Ya ｘ１ Preferred members include single bonds, ester bonds [-C(=O)-O-, -O-C(=O)-], ether bonds (-O-), linear or branched alkylene groups, or combinations thereof, with single bonds and ester bonds [-C(=O)-O-, -O-C(=O)-] being more preferred.

[0162] In the above formula (a10-1), Wa ｘ１ It is an aromatic group. Wa ｘ１ The aromatic group in this case is an aromatic ring which may have substituents (n ａｘ１ A group with 1+1 hydrogen atoms removed is an example. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which part of the ring skeleton is composed of 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. ｘ１ The aromatic group in this can be an aromatic compound containing an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.) (n ａｘ１A group with 1) hydrogen atoms removed can also be cited. Among the above, Wa ｘ１ Examples include benzene, naphthalene, anthracene, or biphenyl (n ａｘ１ A group with (+1) hydrogen atoms removed is preferred, and (n ａｘ１ A group with (+1) hydrogen atoms removed is more preferable, and from benzene (n ａｘ１ A group with 1 hydrogen atom removed is even more preferable.

[0163] Wa ｘ１ The aromatic group in may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, and alkyl halides. Examples of alkyl groups, alkoxy groups, halogen atoms, and alkyl halides as substituents include Ya ｘ１ Examples of substituents for cyclic aliphatic hydrocarbon groups in the above are similar to those listed above. The substituents are preferably linear or branched alkyl groups having 1 to 5 carbon atoms, more preferably linear or branched alkyl groups having 1 to 3 carbon atoms, even more preferably ethyl or methyl groups, and particularly preferably methyl groups. Wa ｘ１ In this case, the aromatic group preferably has no substituents.

[0164] In the above formula (a10-1), n ａｘ１ is an integer of 1 or more, preferably an integer from 1 to 10, more preferably an integer from 1 to 5, even more preferably 1, 2, or 3, and particularly preferably 1 or 2.

[0165] The following are specific examples of the constituent unit (a10) represented by the above formula (a10-1). In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0166]

[0167]

[0168]

[0169] The constituent unit (a10) of component (A1) may be one type or two or more types. Component (A1) may or may not have constituent unit (a10), but it is preferable that it has constituent unit (a10). When component (A1) has constituent unit (a10), the proportion of constituent unit (a10) in component (A1) is preferably 20 to 80 mol%, more preferably 25 to 70 mol%, even more preferably 30 to 60 mol%, and particularly preferably 30 to 50 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). Setting the proportion of constituent unit (a10) above the lower limit makes it easier to increase sensitivity. On the other hand, setting it below the upper limit makes it easier to balance with other constituent units.

[0170] Constituent unit (a2): Component (A1) may or may not have constituent unit (a2) containing a lactone-containing cyclic group (excluding those corresponding to constituent unit (a1)). The lactone-containing cyclic group of constituent unit (a2) is effective in improving the adhesion of the resist film to the substrate when component (A1) is used to form a resist film. Furthermore, having constituent unit (a2) improves lithography characteristics, etc., by having 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.

[0171] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -O-C(=O)- within its cyclic skeleton. The lactone ring is counted as the first ring. If it consists only of a lactone ring, it is called a monocyclic group; if it also has other ring structures, it is called a polycyclic group regardless of those structures. A lactone-containing cyclic group may be a monocyclic group or a polycyclic group. Any lactone-containing cyclic group can be used in the constituent unit (a2) without any particular limitations. Specifically, examples include the groups represented by the following general formulas (a2-r-1) to (a2-r-7).

[0172] [In the formula, Ra' ２１Each of these is 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, or a lactone-containing cyclic group; 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, where n' is an integer from 0 to 2, and m' is 0 or 1. * indicates a bond (the same applies below).

[0173] In the general formulas (a2-r-1) to (a2-r-7), Ra' ２１ The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, etc. Among these, the methyl group or ethyl group is preferred, and the methyl group is particularly preferred. Ra' ２１ The alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the Ra' ２１ Examples of alkyl groups in this context include groups formed by linking an alkyl group with an oxygen atom (-O-). ２１ In this, a fluorine atom is preferred as the halogen atom. Ra' ２１ The halogenated alkyl group in is the Ra' ２１ Examples include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. Fluorinated alkyl groups are preferred as the halogenated alkyl group, and perfluoroalkyl groups are particularly preferred.

[0174] Ra' ２１In -COOR'' and -OC(=O)R'', R'' is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. If R'' is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. If R'' is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, examples include a group obtained by removing one or more hydrogen atoms from a monocycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as bicycloalkanes, tricycloalkanes, or tetracycloalkanes. More specifically, groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as decane and tetracyclododecane. Examples of lactone-containing cyclic groups in R'' include those similar to the groups represented by the general formulas (a²-r-1) to (a²-r-7) above. Ra' ２１ The hydroxyalkyl group in is preferably one having 1 to 6 carbon atoms, specifically the Ra' ２１ Examples include groups in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0175] Ra' ２１ Among the above, it is preferable that each is independently a hydrogen atom or a cyano group.

[0176] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A'' is preferably a linear or branched alkylene group, such as a methylene group, ethylene group, n-propylene group, isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, a specific example is a group in which -O- or -S- is interposed at the end or between carbon atoms of the alkylene group, for example, -O-CH ２ -ien-CH ２ -O-CH ２ -, -S-CH ２ -ien-CH ２ -S-CH ２ Examples include the following. A'' is preferably an alkylene group or -O- having 1 to 5 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0177] The following are specific examples of the groups represented by the general formulas (a²-r-1) to (a²-r-7).

[0178]

[0179]

[0180] Among the constituent units (a2), those derived from acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent are preferred. Such constituent units (a2) are preferably those represented by the following general formula (a2-1).

[0181] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Ya ２１ It is a single bond or a divalent linking group. La ２１ The elements are -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. However, La ２１ If -O-, Ya ２１ It does not become -CO-. Ra ２１ This is a lactone-containing cyclic group.

[0182] In formula (a2-1) above, R is the same as above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or a methyl group is particularly preferred due to their industrial availability.

[0183] In the above formula (a2-1), Ya ２１ The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. ２１ The divalent linking group in the above general formula (a10-1) is Ya ｘ１ Examples include divalent linking groups similar to those in [the relevant context].

[0184] Ya ２１ Preferably, the group is a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0185] In the above formula (a2-1), Ya ２１ It is a single bond, La ２１ It is preferable that it be -COO- or -OCO-.

[0186] In the formula (a2-1), Ra ２１ Ra is a lactone-containing cyclic group. ２１ Suitable lactone-containing cyclic groups in this compound include the groups represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above.

[0187] The constituent unit (a2) of component (A1) may be one type or two or more types. Component (A1) may or may not have constituent unit (a2). If component (A1) has constituent unit (a2), the proportion of constituent unit (a2) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1). If the proportion of constituent unit (a2) is above the preferred lower limit, the effects of including constituent unit (a2) are sufficiently obtained due to the effects described above, and if it is below the upper limit, a balance with other constituent units can be maintained, resulting in good lithography characteristics in various fields.

[0188] Constituent unit (a5): Component (A1) may or may not have a constituent unit (a5) that generates acid upon exposure. Known constituent units (a5) can be used. Having a constituent unit (a5) makes it easier for the acid generated upon exposure to be uniformly distributed within the resist film. Examples of constituent units (a5) include a constituent unit containing the structure described in component (B) below. For example, an example of a constituent unit (a5) is a constituent unit containing a structure represented by any of the general formulas (b-1) to (b-3) below. For example, a constituent unit represented by the following general formula (a5-1) is preferred as a constituent unit (a5).

[0189] [In the formula, R ｍ This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. La ５０ This is a divalent linking group or a single bond. Ra ５０ n is a divalent hydrocarbon group which may have substituents. ａ５ It is an integer between 0 and 2. ５１ It is a divalent linking group. ５ This is a divalent linking group that may have a heteroatom, or a single bond. Ra ５１ and Ra ５２ Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. n5 is an integer from 1 to 4. m is an integer of 1 or more, and M'ｍ＋ This is an onium cation with a valence of m.

[0190] {Anion part} In the above formula (a5-1), R ｍ R is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. ｍ The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. 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 are substituted with halogen atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Fluorine is particularly preferred as the halogen atom in the halogenated alkyl group. ｍ Preferably, the group consists of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, with the hydrogen atom or methyl group being the most preferred due to their industrial availability.

[0191] In the formula (a5-1), La ５０ This is a divalent linking group or a single bond. La ５０ The divalent linking group in is not particularly limited, but preferred examples include a divalent hydrocarbon group which may have substituents, and a divalent linking group which contains a heteroatom, respectively. ｘ１ The divalent linking groups in the above are similar to the divalent hydrocarbon groups that may have substituents and divalent linking groups containing heteroatoms, as exemplified. ５０ Preferably, the bonds are ester bonds [-C(=O)-O-, -O-C(=O)-], ether bonds (-O-), linear or branched alkylene groups, aromatic hydrocarbon groups or combinations thereof, or single bonds. Among these, La ５As such, ester bonds [-C(=O)-O-, -O-C(=O)-] and single bonds are more preferable, and ester bonds [-C(=O)-O-, -O-C(=O)-] are even more preferable.

[0192] In the formula (a5-1), Ra ５０ This is a divalent hydrocarbon group which may have substituents. Ra ５０ The divalent hydrocarbon group in this expression may be an aliphatic hydrocarbon group or an aromatic group.

[0193] ...Ra ５０ In this context, the aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0194] ...Linear or branched aliphatic hydrocarbon group 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, 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 Examples include -]. 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. A branched alkylene group is preferred as the branched aliphatic hydrocarbon group, specifically -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkyl methylene 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 - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２ Examples include alkylalkylene groups such as alkyltetramethylene groups. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0195] The linear or branched aliphatic hydrocarbon group described above may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0196] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups with two hydrogen atoms removed from an aliphatic hydrocarbon ring) which may contain substituents containing heteroatoms in their ring structure, groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a monocycloalkane is preferred. As a monocycloalkane, one having 3 to 6 carbon atoms is preferred, and specifically examples include cyclopentane and cyclohexane. As for the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, those having 7 to 12 carbon atoms are preferred, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0197] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. Preferably, the alkyl group has 1 to 5 carbon atoms, and most preferably it is a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Preferably, the alkoxy group has 1 to 5 carbon atoms, and more preferably it is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group, with methoxy and ethoxy groups being the most preferred. Examples of halogen atoms as substituents include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms being preferred. Examples of alkyl halides as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. The cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure substituted with substituents containing heteroatoms. Substituents containing the heteroatom include -O-, -C(=O)-O-, -S-, and -S(=O). ２ -, -S (=O) ２ -O- is preferred.

[0198] ...Ra ５０ The aromatic group in this expression is a 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, and may have substituents that substitute for the hydrogen atoms of the aromatic ring.

[0199] The aromatic hydrocarbon ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this carbon atom count does not include the carbon atoms in substituents. Specific examples of aromatic rings include benzene, naphthalene, anthracene, and phenanthrene.

[0200] The number of carbon atoms in the aromatic heterocycle is preferably 4 to 30, more preferably 4 to 20, even more preferably 4 to 15, and particularly preferably 4 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents that substitute for hydrogen atoms in the aromatic heterocycle. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, nitrogen atoms, etc. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

[0201] Specific examples of aromatic groups include: a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or the aromatic heterocycle (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or the aromatic heterocycle (aryl group or heteroaryl group) in which one hydrogen atom is replaced by an alkylene group (e.g., a group obtained by removing one more hydrogen atom from the aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0202] The aromatic group preferably has 4 to 30 carbon atoms, more preferably 4 to 20, even more preferably 4 to 15, and particularly preferably 4 to 12. The aromatic group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic group may be substituted with substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and hydroxyl groups. The alkyl group substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of alkoxy groups, halogen atoms, and alkyl halides as substituents include those exemplified as substituents that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0203] In the above formula (a5-1), n ａ５ is an integer between 0 and 2. Among the above, Ra ５０ Preferably, the aliphatic hydrocarbon group is an aliphatic hydrocarbon group containing a ring in its structure, more preferably a cyclic aliphatic hydrocarbon group which may contain substituents containing heteroatoms in its ring structure, and even more preferably a polycyclic or monocyclic alicyclic hydrocarbon group which may have substituents. Alternatively, among the above, Ra ５０ Aromatic groups are preferred.

[0204] n ａ５ If it is 2, then two Ra ５０ These may all be alicyclic hydrocarbon groups which may have substituents, or they may all be aromatic groups which may have substituents, or they may be a combination of alicyclic hydrocarbon groups which may have substituents and aromatic groups which may have substituents.

[0205] In the formula (a5-1), La ５１ It is a divalent linking group. La ５１Examples of divalent linking groups in this context include non-hydrocarbon oxygen atom-containing linking groups such as oxygen atoms (ether bond: -O-), ester bonds (-C(=O)-O-), oxycarbonyl groups (-O-C(=O)-), amide bonds (-C(=O)-NH-), carbonyl groups (-C(=O)-), and carbonate bonds (-O-C(=O)-O-); and combinations of these non-hydrocarbon oxygen atom-containing linking groups with alkylene groups. In addition to these combinations, sulfonyl groups (-SO) may be added. ２ A ∫(-) may be linked. Examples of such divalent linking groups include the linking groups represented by the following general formulas (L-al-1) to (L-al-8). Note that in the following general formulas (L-al-1) to (L-al-8), Ra in formula (a5-1) above ５０ The combination with this is V' in the following general formulas (L-al-1) to (L-al-8). １０１ That is the case.

[0206] [In the formula, V' １０１ V' is a single bond or an alkylene group having 1 to 5 carbon atoms. １０２ [This refers to a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]

[0207] 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.

[0208] V' １０１ and V' １０２ The alkylene group in V' may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. １０１ and V' １０２ Specifically, the alkylene group in this case is the methylene group [-CH ２ -come; -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) ２ -, -C(CH ３ ) (CH ２CH 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 -come; -CH(CH ３ )CH ２ -, -CH(CH ３ )CH(CH ３ )-,-C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ )CH ２ - Alkylethylene groups such as; trimethylene group (n-propylene group) [-CH ２ CH ２ CH ２ -come; -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as; tetramethylene groups [-CH ２ CH ２ CH ２ CH ２ -come; -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２ - Alkyltetramethylene groups such as; pentamethylene groups [-CH ２ CH ２ CH ２ CH ２ CH ２ -] are some examples. Also, V' １０１ or V' １０２Some 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 preferably 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), and more preferably a cyclohexylene group, a 1,5-adamantilene group, or a 2,6-adamantilene group.

[0209] La ５１ Preferably, the linking group is a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably the linking groups represented by the above formulas (L-al-1) to (L-al-5) and (L-al-8), and even more preferably the linking group represented by the above formula (L-al-3) or (L-al-8).

[0210] In the above formula (a5-1), Ya ５ This is a divalent linking group that may have a heteroatom, or a single bond. ５ The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. ５ In the above, the divalent hydrocarbon group which may have substituents, and the divalent linking group which contains a heteroatom, are as follows: ｘ１ This is similar to the divalent linking groups exemplified in the above, such as divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. Among the above, Ya ５ The alkylene group is preferably a linear or branched alkylene group, or a single bond, with a single bond being more preferable.

[0211] In the formula (a5-1), Ra ５１ and Ra ５２ Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. Ra ５１ and Ra ５２ The fluorinated alkyl group in is preferably a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms, and more preferably a trifluoromethyl group. In formula (a5-1), SO ３ － Ra bonded to the adjacent carbon atom５１ and Ra ５２ From the viewpoint of acid strength, it is preferable that at least one of these atoms is a fluorine atom.

[0212] In the above formula (a5-1), n5 is an integer from 1 to 4, and is preferably 1, 2, or 3.

[0213] {Cation part} In the above formula (a5-1), M' ｍ＋ This represents an m-valent onium cation. Among these, M' ｍ＋ m is preferably a sulfonium cation or an iodonium cation.

[0214] Preferred cation portion ((M' ｍ＋ ) １／ｍ Examples of these include organic cations represented by the following general formulas (ca-1) to (ca-3).

[0215] [In the formula, R ２０１ ~R ２０７ Each of these independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. ２０１ ~R ２０３ , R ２０６ ~R ２０７ These atoms may bond to each other to form a ring with the sulfur atom in the formula. ２０８ ~R ２０９ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ２１０ This may be an aryl group having a substituent, an alkyl group having a substituent, an alkenyl group having a substituent, or an -SO group having a substituent. ２ - Contains a cyclic group. L ２０１ This represents -C(=O)- or -C(=O)-O-.

[0216] In the above general formulas (ca-1) to (ca-3), R ２０１ ~R ２０７ Examples of aryl groups in this compound include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. ２０１ ~R ２０７The alkyl group in is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７ The alkenyl group in is preferably one with 2 to 10 carbon atoms. ２０１ ~R ２０７ , and R ２１０ Examples of substituents that may be present include alkyl groups, halogen atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the following general formulas (ca-r-1) to (ca-r-7).

[0217] [In the formula, R' ２０１ Each of these is independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group.

[0218] A cyclic group which may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which may be an aromatic group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated.

[0219] R' ２０１ The aromatic group in this context is a hydrocarbon group having an 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, polycyclic, or have substituents that substitute for the hydrogen atoms of the aromatic ring.

[0220] Aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles, in which part of the ring skeleton is composed of heteroatoms.

[0221] The aromatic hydrocarbon group preferably has 5 to 30 carbon atoms, more preferably 6 to 20, even more preferably 6 to 15, and particularly preferably 6 to 10. However, this carbon atom count does not include the carbon atoms in substituents. R' ２０１Examples of aromatic hydrocarbon rings in this context include benzene, fluorene, naphthalene, anthracene, and phenanthrene.

[0222] The number of carbon atoms in the aromatic heterocycle is preferably 4 to 30, more preferably 4 to 20, even more preferably 4 to 15, and particularly preferably 4 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents that substitute for hydrogen atoms in the aromatic heterocycle. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, nitrogen atoms, etc. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

[0223] The number of carbon atoms in the aromatic group is preferably 4 to 30, more preferably 4 to 25, even more preferably 4 to 20, particularly preferably 4 to 15, and most preferably 4 to 10. ２０１ Specific examples of aromatic groups in this context include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: e.g., phenyl group, naphthyl group, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0224] R' ２０１The cyclic aliphatic hydrocarbon group in this context refers to an aliphatic hydrocarbon group that contains a ring in its structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include alicyclic hydrocarbon groups (groups from 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 in the middle of a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group from which one or more hydrogen atoms have been removed from a monocycloalkane. The preferred monocycloalkane has 3 to 6 carbon atoms, and specifically includes cyclopentane and cyclohexane. A preferred polycyclic alicyclic hydrocarbon group is a group from which one or more hydrogen atoms have been removed from a polycycloalkane, and the preferred polycycloalkane has 7 to 30 carbon atoms. Among these, the polycycloalkanes include adamantane, norbornane, isobornane, and tricyclo[5.2.1.0 ２，６ Polycycloalkanes having a cross-linked ring system polycyclic skeleton, such as decane and tetracyclododecane; polycycloalkanes having a fused ring system polycyclic skeleton, such as a cyclic group having a steroid skeleton, are more preferred.

[0225] Among them, R' ２０１ The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, with adamantyl and norbornyl groups being particularly preferred, and the adamantyl group being the most preferred.

[0226] 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, even more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. A linear alkylene group is preferred as the linear aliphatic hydrocarbon group, specifically a methylene group [-CH₂]. ２-], ethylene group [- (CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ Examples include -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 - Alkyl methylene 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 - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２Examples include alkylalkylene groups such as alkyltetramethylene groups. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0227] Also, R' ２０１ The cyclic hydrocarbon group in may contain heteroatoms, such as heterocycles. Specifically, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above, and -SO groups represented by the general formulas (b5-r-1) to (b5-r-4) mentioned later. ２ - Examples include cyclic groups and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16).

[0228]

[0229] R' ２０１ Examples of substituents on the cyclic group include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, and nitro groups. Preferred alkyl groups as substituents are alkyl groups having 1 to 5 carbon atoms, with methyl, ethyl, propyl, n-butyl, and tert-butyl groups being the most preferred. Preferred alkoxy groups as substituents are alkoxy groups having 1 to 5 carbon atoms, with methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, and tert-butoxy groups being more preferred, with methoxy and ethoxy groups being the most preferred. Preferred halogen atoms as substituents are fluorine atoms. Examples of alkyl halides as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms are substituted with the halogen atoms. Carbonyl groups as substituents are methylene groups (-CH) that constitute the cyclic hydrocarbon group. ２ It is a substituting group for -).

[0230] A chain-like alkyl group which may have substituents: R' ２０１The linear alkyl group may be linear or branched. Linear alkyl groups preferably have 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Branched alkyl groups preferably have 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0231] A chain-like alkenyl group which may have substituents: R' ２０１ The linear alkenyl group may be linear or branched, preferably having 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 vinyl groups, propenyl groups (allyl groups), and butenyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the linear alkenyl groups listed above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0232] R' ２０１ Examples of substituents in the chain-like alkyl or alkenyl group include alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R'. ２０１ Examples include cyclic groups in this context.

[0233] R' ２０１The optionally substituted cyclic groups, optionally substituted linear alkyl groups, or optionally substituted linear alkenyl groups include, in addition to those mentioned above, the optionally substituted cyclic groups or optionally substituted linear alkyl groups, as well as those similar to tertiary alkyl ester type acid-dissociable groups.

[0234] Among them, R' ２０１ The cyclic group is preferably a cyclic group which may have substituents, and more preferably a cyclic hydrocarbon group which may have substituents. More specifically, for example, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7) respectively; and -SO2 groups represented by the general formulas (b5-r-1) to (b5-r-4) respectively described later. ２ - A cyclic group is preferred.

[0235] In the above general formulas (ca-1) to (ca-3), R ２０１ ~R ２０３ , R ２０６ ~R ２０７ When these atoms bond to each other and form a ring with the sulfur atom in the formula, they can be heteroatoms such as sulfur, oxygen, and nitrogen atoms, or 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. ) may be bonded via functional groups such as ). The formed ring preferably has 3 to 10 members, and particularly preferably 5 to 7 members, including the sulfur atom in its ring skeleton. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthlene ring, a phenoxatiyne ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and the like.

[0236] R ２０８ ~R ２０９Each of these 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. If an alkyl group is present, it may bond to each other to form a ring.

[0237] R ２１０ This may be an aryl group having a substituent, an alkyl group having a substituent, an alkenyl group having a substituent, or an -SO group having a substituent. ２ - Contains a cyclic group. R ２１０ Examples of aryl groups in this compound include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. ２１０ The alkyl group in is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. ２１０ The alkenyl group in is preferably one with 2 to 10 carbon atoms. ２１０ In, -SO ２ - Any cyclic group can be used without any particular limitations. Specifically, the groups represented by the following general formulas (b5-r-1) to (b5-r-4) can be used, such as "-SO ２ A polycyclic group containing a polycyclic group is preferred, and a group represented by the general formula (b5-r-1) is more preferred.

[0238] [In the formula, Rb' ５１ Each of these is 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, or -SO ２ - It is a cyclic group containing; B'' 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 from 0 to 2. * indicates a bond.

[0239] In the general formulas (b5-r-1) to (b5-r-2) above, B'' 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. B'' 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 even more preferably a methylene group.

[0240] In the above general formulas (b5-r-1) to (b5-r-4), Rb' ５１ Each of these is 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, and among these, each is preferably independently a hydrogen atom or a cyano group.

[0241] Specific examples of the groups represented by the general formulas (b5-r-1) to (b5-r-4) are given below. In the formulas, "Ac" indicates an acetyl group.

[0242]

[0243]

[0244]

[0245] Specific examples of suitable cations represented by the above formula (ca-1) include the cations represented by the following chemical formulas.

[0246]

[0247]

[0248] [In the formula, g1, g2, and g3 represent the number of repetitions, where g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 1 to 20.]

[0249]

[0250]

[0251] [In the formula, R” ２０１ is a hydrogen atom or a substituent, and the substituent is the aforementioned R ２０１ ~R２０７ , and R ２１０ These are the same as those listed as substituents that may be present.

[0252]

[0253] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0254]

[0255]

[0256] Specific examples of suitable cations represented by the above formula (ca-3) include the cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0257]

[0258] The cation portion in the above formula (a5-1) ((M' ｍ＋ ) １／ｍ As the cation, a sulfonium cation is preferred, the cations represented by formulas (ca-1) to (ca-3) are more preferred, the cation represented by formula (ca-1) is even more preferred, and the cations represented by formulas (ca-1-1) to (ca-1-104) are particularly preferred. Particularly from the viewpoint of increasing sensitivity, a preferred cation represented by formula (ca-1) is one having electron-withdrawing groups such as a fluorine atom, an iodine atom, a fluorinated alkyl group, or a sulfonyl group as a substituent. For example, a cation selected from the group consisting of the cations represented by the above chemical formulas (ca-1-44), (ca-1-71) to (ca-1-104) is particularly preferred.

[0259] Cationic part ((M' ｍ＋ ) １／ｍ The cation is particularly preferably represented by the following general formula (ca-h-1).

[0260] [wherein, Rf ２０１ ~Rf ２０３Each of these independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. Rf ２０１ ~Rf ２０３ These atoms may bond to each other to form a ring with the sulfur atom in the formula. However, Rf ２０１ ~Rf ２０３ At least one of them has at least one halogen atom.

[0261] Rf in the above formula (ca-h-1) ２０１ ~Rf ２０３ R in the above formula (ca-1) is ２０１ ~R ２０３ The same applies to each of the above. However, Rf ２０１ ~Rf ２０３ At least one of these has at least one halogen atom. The halogen atom is preferably at least one selected from the group consisting of fluorine, iodine, and bromine atoms, and more preferably at least one selected from the group consisting of fluorine and iodine atoms. The cation represented by formula (ca-h-1) preferably contains three or more halogen atoms, more preferably four or more halogen atoms, even more preferably five or more halogen atoms, and particularly preferably six or more halogen atoms. Rf ２０１ ~Rf ２０３ Any one of them may have three or more halogen atoms, Rf ２０１ ~Rf ２０３ The total number of halogen atoms contained in Rf may be three or more. ２０１ ~Rf ２０３The substituent is preferably an aryl group which may have substituents, and more preferably an aryl group which has substituents containing a halogen atom. The substituent containing a halogen atom is preferably at least one selected from the group consisting of halogen atoms and alkyl halides, more preferably at least one selected from the group consisting of fluorine atoms, iodine atoms and alkyl fluorides, even more preferably at least one selected from the group consisting of fluorine atoms, iodine atoms and trifluoromethyl groups, and particularly preferably at least one selected from the group consisting of fluorine atoms and iodine atoms. As such a cation portion, a cation selected from the group consisting of cations represented by the chemical formulas (ca-1-44) and (ca-1-71) to (ca-1-104), respectively, is particularly preferred.

[0262] The following are preferred examples of the constituent unit (a5). In the following formula, R α m and M' represent a hydrogen atom, a methyl group, or a trifluoromethyl group. ｍ＋ These are m and M' in the above general formula (a5-1). ｍ＋ It is similar to that.

[0263]

[0264]

[0265]

[0266] The constituent unit (a5) of component (A1) may be one type or two or more types. When component (A1) has constituent unit (a5), the proportion of constituent unit (a5) in component (A1) is preferably 5 to 25 mol%, more preferably 10 to 20 mol%, and even more preferably 15 to 20 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1). If the proportion of constituent unit (a5) is above the lower limit of the above preferred range, it becomes easier to achieve further increases in sensitivity and improvements in resolution. On the other hand, if it is below the upper limit of the above preferred range, it becomes easier to balance with other constituent units.

[0267] Constituent unit (a6): Constituent unit (a6) is a constituent unit that has acid diffusion control properties. Component (A1) may or may not contain constituent unit (a6). Constituent unit (a6) can be one of known types. Examples of constituent unit (a6) include constituent units containing the structures described in components (D1) and (D2) below. For example, a constituent unit containing a structure represented by any of the general formulas (d1-1) to (d1-3) below can be used.

[0268] The constituent unit (a6) of component (A1) may be one type or two or more types. When component (A1) has constituent unit (a6), the proportion of constituent unit (a6) in component (A1) is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 3 to 10 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). If the proportion of constituent unit (a6) is above the lower limit of the above preferred range, it becomes easier to achieve even higher sensitivity. On the other hand, if it is below the upper limit of the above preferred range, it becomes easier to balance with other constituent units.

[0269] Constituent unit (a8): Constituent unit (a8) is a constituent unit derived from the compound represented by the following general formula (a8-1). Component (A1) may or may not have constituent unit (a8).

[0270] [In the formula, W ２ This is a polymerizable group-containing group. ｘ２ is a single bond or (n ａｘ２ It is a linking group with a +1 valence. ｘ２ and W ２ It may form a fused ring. １ R is a fluorinated alkyl group having 1 to 12 carbon atoms. ２ R is an organic group having 1 to 12 carbon atoms, which may contain a fluorine atom, or a hydrogen atom. ２ and Ya ｘ２ These may be bonded to each other to form a ring structure. ａｘ２ [This is an integer between 1 and 3.]

[0271] W ２In the context of polymerizable group-containing groups, "polymerizable group" refers to a group that enables a compound containing a polymerizable group to polymerize by radical polymerization or the like, and includes, for example, a group containing multiple bonds between carbon atoms, such as an ethylenic double bond.

[0272] The polymerizable group-containing group may be a group composed solely of a polymerizable group, or a group composed of a polymerizable group and other groups other than the polymerizable group. Examples of other groups other than the polymerizable group include divalent hydrocarbon groups which may have substituents, and divalent linking groups containing heteroatoms. An example of a polymerizable group-containing group is a group with the chemical formula: C(R Ｘ１１ ) (Caution Ｘ１２ ) = C(R Ｘ１３ )-Ya ｘ０ The group represented by - is preferably mentioned. In this chemical formula, R Ｘ１１ , R Ｘ１２ and R Ｘ１３ These are, respectively, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya ｘ０ It is a single bond or a divalent linking group.

[0273] Ya ｘ２ and W ２ The condensed ring formed by these is W ２ Polymerizable groups of the site and Ya ｘ２ The condensed ring formed by W ２ Other groups besides the polymerizable group of the site and Ya ｘ２ A condensed ring formed by these is an example. ｘ２ and W ２ The fused ring formed by these two components may have substituents.

[0274] The following shows specific examples of constituent units (a8). In the following formula, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0275]

[0276] Among the above examples, the constituent unit (a8) is preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09), and (a8-1-10), and more preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a8-1-01) to (a8-1-04) and (a8-1-09).

[0277] The constituent units (a8) of component (A1) may be one type or two or more types. Component (A1) may or may not have constituent units (a8). The proportion of constituent units (a8) in component (A1) is preferably 0 to 50 mol%, and more preferably 0 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1).

[0278] The (A1) component contained in the resist composition may be used alone or in combination of two or more types.

[0279] The (A1-0) component contained in the resist composition may be used alone or in combination of two or more types. In the resist composition of this embodiment, the (A1-0) component is a polymer having an "end group (i-1)" at at least one end of the main chain. Examples include: a polymer compound having a structural unit (a1) and a structural unit (a10) in addition to the end group (i-1); a polymer compound having a structural unit (a1), a structural unit (a10), and a structural unit (a5) in addition to the end group (i-1); and a polymer compound having a structural unit (a1), a structural unit (a10), a structural unit (a5), and a structural unit (a6) in addition to the end group (i-1). Preferred (A1-0) components include: polymer compounds having the terminal group (i-1) and consisting of constituent units (a1) and (a10); polymer compounds having the terminal group (i-1) and consisting of constituent units (a1), (a10), and (a5); and polymer compounds having the terminal group (i-1) and consisting of constituent units (a1), (a10), (a5), and (a6).

[0280] With respect to component (A1-0), in a polymer compound consisting of constituent unit (a1) and constituent unit (a10), the proportion of constituent unit (a1) in the polymer compound is preferably 25 to 75 mol%, more preferably 50 to 70 mol%, and even more preferably 55 to 65 mol%, based on the total amount (100 mol%) of all constituent units constituting the polymer compound. The proportion of constituent unit (a10) in the polymer compound is preferably 25 to 75 mol%, more preferably 30 to 50 mol%, and even more preferably 35 to 45 mol%, based on the total amount (100 mol%) of all constituent units constituting the polymer compound.

[0281] Regarding component (A1-0), in a polymer compound consisting of constituent units (a1), (a10), and (a5), the proportion of constituent unit (a1) in the polymer compound is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%, based on the total amount of all constituent units constituting the polymer compound (100 mol%). The proportion of constituent unit (a10) in the polymer compound is preferably 20 to 45 mol%, more preferably 25 to 45 mol%, and even more preferably 30 to 40 mol%, based on the total amount of all constituent units constituting the polymer compound (100 mol%). The proportion of constituent unit (a5) in the polymer compound is preferably 5 to 30 mol%, more preferably 5 to 25 mol%, and even more preferably 10 to 20 mol%, based on the total amount of all constituent units constituting the polymer compound (100 mol%).

[0282] Regarding component (A1-0), in a polymer compound consisting of constituent units (a1), (a10), (a5), and (a6), the proportion of constituent unit (a1) in the polymer compound is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%, based on the total amount (100 mol%) of all constituent units constituting the polymer compound. The proportion of constituent unit (a10) in the polymer compound is preferably 20 to 35 mol%, more preferably 23 to 40 mol%, and even more preferably 27 to 35 mol%, based on the total amount (100 mol%) of all constituent units constituting the polymer compound. The proportion of constituent unit (a5) in the polymer compound is preferably 4 to 25 mol%, more preferably 5 to 20 mol%, and even more preferably 10 to 20 mol%, based on the total amount (100 mol%) of all constituent units constituting the polymer compound. The proportion of constituent units (a6) in the polymer compound is preferably 1 to 15 mol%, more preferably 2 to 10 mol%, and even more preferably 3 to 5 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0283] Such (A1-0) components can be produced, for example, by dissolving monomers that induce each constituent unit in a polymerization solvent, adding a chain transfer agent selected such that at least one end of the polymer's main chain becomes a terminal group (i-1), and then polymerizing. Alternatively, such (A1-0) components can be produced by dissolving monomers that induce constituent unit (a1), monomers that induce constituent unit (a10), and monomers that induce any constituent unit (e.g., constituent unit (a5), constituent unit (a6), etc.) in a polymerization solvent, adding a chain transfer agent selected such that at least one end of the polymer's main chain becomes a terminal group (i-1), polymerizing, and then carrying out a deprotection reaction.

[0284] In the resist composition of this embodiment, component (A1-0) is preferably a polymer obtained by a chain transfer reaction using a chain transfer agent containing a thiol compound represented by the following general formula (I) (hereinafter also referred to as "compound (I)"), as this easily improves sensitivity, roughness, and stability over time when used in the resist composition.

[0285] [wherein Xa １ It is an alkylene group. (Rpg) １ RPG ２ and RPG ３ These are each independently hydrocarbon groups that may have substituents. ２ and RPG ３ These may be joined together to form a ring.

[0286] In the above formula (I), Xa １ RPG １ RPG ２ and RPG ３ This is Xa in the above formula (i-1) １ RPG １ RPG ２ and RPG ３ It is similar to that.

[0287] Examples of preferred compounds (I) include those represented by the following formulas (I-1) to (I-16).

[0288]

[0289] In particular, as compound (I), compounds represented by formulas (I-1) to (I-10) are preferred from the viewpoint of sensitivity and LWR, and compounds represented by formulas (I-4), (I-5), (I-9), and (I-10) are more preferred.

[0290] The weight-average molecular weight (Mw) of component (A1-0) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and even more preferably 5,000 to 30,000. If the Mw of component (A1-0) is below the upper limit of the above preferred range, it has sufficient solubility in resist solvents for use as a resist, while if it is above the lower limit of the above preferred range, it has good dry etching resistance and a good cross-sectional shape of the resist pattern. The dispersion degree (Mw / Mn) of component (A1-0) 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. Mn represents the number-average molecular weight.

[0291] ...Regarding component (A2) Component (A2) is a polymer whose solubility in the developer changes due to the action of an acid (excluding those corresponding to component (A1-0)). Component (A2) and component (A1-0) differ in at least the structure of the terminal groups at the ends of the main chain. Preferably, component (A2) has a constituent unit (a1) that contains an acid-degradable group whose polarity increases due to the action of an acid, as described above. Preferred component (A2) may have other constituent units in addition to constituent unit (a1) as needed. Examples of other constituent units include the constituent units (a10), (a2), (a5), (a6), and (a8) described above.

[0292] Such component (A2) can be produced by dissolving monomers that induce each constituent unit in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) and polymerizing the mixture. Alternatively, such component (A2) can be produced by dissolving monomers that induce constituent unit (a1), monomers that induce constituent unit (a10), and monomers that induce any constituent unit (e.g., constituent unit (a5), constituent unit (a6), etc.) in a polymerization solvent, adding a radical polymerization initiator as described above and polymerizing the mixture, and then carrying out a deprotection reaction.

[0293] The weight-average molecular weight (Mw) of component (A2) (based on polystyrene equivalent by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and even more preferably 5,000 to 30,000. If the Mw of component (A2) is below the upper limit of the preferred range described above, it has sufficient solubility in the resist solvent for use as a resist, while if it is above the lower limit of the preferred range described above, it has good dry etching resistance and a good cross-sectional shape of the resist pattern. The dispersion degree (Mw / Mn) of component (A2) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Mn represents the number-average molecular weight.

[0294] In the resist composition of this embodiment, component (A1) may consist only of component (A1-0), or it may be a combination of component (A1-0) and component (A2). The proportion of component (A1) in component (A1) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of component (A1). When the proportion is 25% by mass or more, sensitivity and roughness are easily improved, and the storage stability of the resist composition is also easily improved.

[0295] Regarding component (A3), the resist composition of this embodiment may also use a base component (hereinafter referred to as "component (A3)") as component (A), which does not fall under component (A1) and whose solubility in the developer changes due to the action of an acid. Component (A3) is not particularly limited and may be arbitrarily selected from a large number of base components conventionally known for chemically amplified resist compositions.

[0296] In the resist composition of this embodiment, the content of component (A) may be adjusted according to the resist film thickness to be formed.

[0297] <Other Components> In addition to component (A) described above, the resist composition of this embodiment may further contain other components. Examples of other components include components (B), (D), (E), (F), and (S) shown below.

[0298] <Acid generator component (B)>The resist composition of this embodiment may contain an acid generator component (B) that generates an acid upon exposure. The component (B) is not particularly limited, and those 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 bisaryl sulfonyldiazomethanes and poly(bissulfonyl)diazomethanes; and various types such as nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. As the form of containing the component (B), it may be in the form of a compound, may be in the form incorporated into the component (A1) as the above-mentioned structural unit (a5), or may be in both of these forms.

[0299] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as the "(b-1) component"), a compound represented by the general formula (b-2) (hereinafter also referred to as the "(b-2) component"), or a compound represented by the general formula (b-3) (hereinafter also referred to as the "(b-3) component").

[0300] [In the formula, R １０１ and R １０４ to R １０８ are each independently a cyclic group that may have a substituent, a chain-like alkyl group that may have a substituent, or a chain-like alkenyl group that may have a substituent.R １０４ and R １０５ may be bonded to each other to form a ring structure.R １０２ is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom.Y １０１ is a divalent linking group containing an oxygen atom or a single bond.V １０１ to V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. However, Y １０１ and V １０１ do not simultaneously become a single bond.L １０１ to L １０２is, independently of each other, a single bond or an oxygen atom. L １０３ ~L １０５ is, independently of each other, a single bond, -CO- or -SO ２ -. m is an integer of 1 or more, and M' ｍ＋ is an m-valent onium cation. ]

[0301] {Anion part} ・ In the anion formula (b-1) in the component (b-1), R １０１ is 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.

[0302] 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 having no aromaticity. Further, the aliphatic hydrocarbon group is preferably saturated.

[0303] R １０１ The aromatic group in is a 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, polycyclic, or may have a substituent that substitutes a hydrogen atom of the aromatic ring.

[0304] Examples of the aromatic ring include an aromatic hydrocarbon ring and an aromatic heterocyclic ring in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms.

[0305] The number of carbon atoms of the aromatic hydrocarbon ring is preferably 4 to 30, more preferably 4 to 25, still more preferably 4 to 20, particularly preferably 4 to 15, and most preferably 4 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R １０１ Specific examples of the aromatic hydrocarbon ring in include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and the like.

[0306] The number of carbon atoms in the aromatic heterocycle is preferably 4 to 30, more preferably 4 to 20, even more preferably 4 to 15, and particularly preferably 4 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents that substitute for hydrogen atoms in the aromatic heterocycle. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, nitrogen atoms, etc. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

[0307] The number of carbon atoms in the aromatic group is preferably 4 to 30, more preferably 4 to 25, even more preferably 4 to 20, particularly preferably 4 to 15, and most preferably 4 to 10. １０１ Specific examples of aromatic groups in this context include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (for example, benzyl groups, phenethyl groups, 1-naphthylmethyl groups, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0308] R １０１The cyclic aliphatic hydrocarbon group in this context refers to an aliphatic hydrocarbon group that contains a ring in its structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include alicyclic hydrocarbon groups (groups from 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 in the middle of a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group from which one or more hydrogen atoms have been removed from a monocycloalkane. The preferred monocycloalkane has 3 to 6 carbon atoms, and specifically includes cyclopentane and cyclohexane. A preferred polycyclic alicyclic hydrocarbon group is a group from which one or more hydrogen atoms have been removed from a polycycloalkane, and the preferred polycycloalkane has 7 to 30 carbon atoms. Among these, the polycycloalkanes include adamantane, norbornane, isobornane, and tricyclo[5.2.1.0 ２，６ Polycycloalkanes having a cross-linked ring system polycyclic skeleton, such as decane and tetracyclododecane; polycycloalkanes having a fused ring system polycyclic skeleton, such as a cyclic group having a steroid skeleton, are more preferred.

[0309] Among them, R １０１ The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, even more preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0310] 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. A linear alkylene group is preferred as the linear aliphatic hydrocarbon group, specifically a methylene group [-CH₂]. ２ -], ethylene group [- (CH ２ )２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ Examples include -]. 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, even more preferably 3 or 4, and most preferably 3. A branched alkylene group is preferred as the branched aliphatic hydrocarbon group, 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 - Alkyl methylene 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 - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH２ CH(CH ３ )CH ２ CH ２ - and other alkyl alkylene groups such as alkyl tetramethylene groups are exemplified. As the alkyl group in the alkyl alkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0311] Also, the cyclic hydrocarbon group in R １０１ may contain a hetero atom such as a heterocyclic ring. Specifically, the lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7), the -SO ２ -containing cyclic group represented by the general formulas (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the chemical formulas (r-hr-1) to (r-hr-16) are exemplified.

[0312] The substituents in the cyclic group of R １０１ include, for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, etc. As the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group, and most preferably a methoxy group and an ethoxy group. As the halogen atom as a substituent, a fluorine atom, a bromine atom, and an iodine atom are preferable. As the halogenated alkyl group as a substituent, a group in which a part or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc., are substituted with the halogen atom is exemplified. The carbonyl group as a substituent is a group that substitutes the methylene group (-CH ２ -) constituting the cyclic hydrocarbon group.

[0313] The R １０１The cyclic hydrocarbon group in may be a fused ring group containing a fused ring formed by the fusion of an aliphatic hydrocarbon ring and an aromatic ring. Examples of the fused ring include a polycycloalkane having a bridging ring system with one or more aromatic rings fused to it. Specific examples of the bridging ring system 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 formed by the fusion of two or three aromatic rings to a bicycloalkane, and more preferably a group containing a fused ring formed by the fusion of two or three aromatic rings to bicyclo[2.2.2]octane. １０１ Specific examples of fused ring groups in this context include the groups represented by the following formulas (r-br-1) to (r-br-2). In the formulas, * represents Y in formula (b-1). １０１ This represents a coupling that connects to something.

[0314]

[0315] R １０１ Examples of substituents that the fused ring group in R may have include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, aromatic groups, alicyclic hydrocarbon groups, etc. The alkyl groups, alkoxy groups, halogen atoms, and alkyl halides as substituents of the fused ring group are as described above. １０１ Examples of substituents for cyclic groups include those similar to those listed in the above. Aromatic groups as substituents for the fused cyclic group include groups obtained by removing one hydrogen atom from an aromatic ring (aryl groups: e.g., phenyl group, naphthyl group, etc.), groups in which one hydrogen atom of the aromatic ring is replaced by an alkylene group (e.g., 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). Alicyclic hydrocarbon groups as substituents for the fused cyclic group include groups obtained by removing one hydrogen atom from monocycloalkanes such as cyclopentane and cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６] Groups obtained by removing one hydrogen atom from polycycloalkanes such as decane and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), respectively; -SO groups represented by the general formulas (b5-r-1) to (b5-r-4), respectively. ２ - Containing cyclic groups; examples include heterocyclic groups represented by formulas (r-hr-7) to (r-hr-16), respectively.

[0316] A chain-like alkyl group which may have substituents: R １０１ The linear alkyl group may be linear or branched. Linear alkyl groups preferably have 1 to 20 carbon atoms, more preferably 1 to 15, and most preferably 1 to 10. Branched alkyl groups preferably have 3 to 20 carbon atoms, more preferably 3 to 15, and most preferably 3 to 10. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0317] A chain-like alkenyl group which may have substituents: R １０１ The linear alkenyl group may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butenyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the linear alkenyl groups listed above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0318] R １０１Examples of substituents in the chain-like alkyl or alkenyl group include alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R １０１ Examples include cyclic groups in this context.

[0319] In formula (b-1), Y １０１ Y is a single bond or a divalent linking group containing an oxygen atom. １０１ If Y is a divalent linking group containing an oxygen atom, １０１ It may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, etc. Examples of divalent linking groups containing oxygen atoms include the linking groups represented by the above general formulas (L-al-1) to (L-al-8). Note that in the above general formulas (L-al-1) to (L-al-8), R in formula (b-1) １０１ The V' in the above general formulas (L-al-1) to (L-al-8) is what combines with it. １０１ That is the case.

[0320] In formula (b-1), V １０１ These are single bonds, alkylene groups, or fluorinated alkylene groups. Among them, V １０１ It is preferable that the fluorinated alkylene group is a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0321] In formula (b-1), R １０２ R is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０２ It is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0322] A specific example of the anion part represented by formula (b-1) is, for example, Y １０１ When it is a single bond, examples include fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anions and perfluorobutanesulfonate anions; Y １０１ When is a divalent linking group containing an oxygen atom, anions represented by any of the following formulas (an-1) to (an-3) are included.

[0323] [In the formula, R” １０１ R'' is an optionally substituted aliphatic cyclic group, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-16), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), an optionally substituted linear alkyl group, or an optionally substituted aromatic group. １０２ This includes an aliphatic cyclic group which may have substituents, a fused cyclic group represented by formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), respectively, or a -SO group represented by the general formulas (b5-r-1) to (b5-r-4), respectively. ２ - Contains a cyclic group. R'' １０３ V'' is an optionally substituted aromatic group, an optionally substituted aliphatic cyclic group, or an optionally substituted linear alkenyl group. １０１ This is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. １０２ [wherein 'v' is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; where 'v' is an independent integer from 0 to 3, where 'q' is an independent integer from 0 to 20, and where 'n' is 0 or 1.]

[0324] R" １０１ , R” １０２ and R” １０３ The aliphatic cyclic group which may have substituents is R in formula (b-1) above. １０１ It is preferable that the substituent is the group exemplified as a cyclic aliphatic hydrocarbon group in formula (b-1). １０１ Examples include substituents similar to those that may be substituted for the cyclic aliphatic hydrocarbon group in the above.

[0325] R" １０１ and R” １０３ The aromatic group which may have substituents in formula (b-1) is R １０１ It is preferable that the substituent is the group exemplified as an aromatic group in the cyclic hydrocarbon group in the above formula (b-1). １０１Examples include substituents similar to those that may be substituted for the aromatic group in the above.

[0326] R" １０１ The chain-like alkyl group which may have substituents in formula (b-1) is R １０１ The group exemplified as the chain-like alkyl group in R is preferred. １０３ The chain-like alkenyl group which may have substituents in formula (b-1) is R １０１ It is preferable that the group is one of the examples given as a chain-like alkenyl group in the formula.

[0327] • In the anionic formula (b-2) of component (b-2), R １０４ , R １０５ Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). １０１ Similar examples can be given. However, R １０４ , R １０５ They may be bonded to each other to form a ring. １０４ , R １０５ The linear alkyl group is preferably a substituted linear alkyl group, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms in the linear 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-like alkyl group is preferably small within the above range of carbon atoms, for reasons such as good solubility in the resist solvent. １０４ , R １０５In the chain-like alkyl group, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acidity and the better the transparency to high-energy light and electron beams below 250 nm, which is preferable. The proportion of fluorine atoms in the chain-like 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 These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group, and each is V in formula (b-1). １０１ Similar examples include the following. In equation (b-2), L １０１ , L １０２ Each of these is either a single bond or an oxygen atom, independently of the others.

[0328] • In the anionic formula (b-3) of component (b-3), R １０６ ~R １０８ Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). １０１ Similar examples can be given. In equation (b-3), L １０３ ~L １０５ These are, independently, single bonds, -CO-, or -SO-. ２ - is the case.

[0329] Among the above, the anion portion of component (B) is preferably the anion in component (b-1), and more preferably the anion represented by the formula (an-1).

[0330] {Cation part} In the above formulas (b-1), (b-2), and (b-3), M' ｍ＋ This represents an m-valent onium cation. Among these, sulfonium cations and iodonium cations are preferred. m is an integer of 1 or greater.

[0331] As the cation portion of component (B), a sulfonium cation is preferred, the cations represented by formulas (ca-1) to (ca-3) are more preferred, the cation represented by formula (ca-1) is even more preferred, and the cations represented by formulas (ca-1-1) to (ca-1-104) are particularly preferred. Particularly from the viewpoint of increasing sensitivity and reducing roughness, the cation portion of component (B) is even more preferably a cation represented by the general formula (ca-h-1), and a cation selected from the group consisting of the cations represented by the chemical formulas (ca-1-44) and (ca-1-71) to (ca-1-104) is particularly preferred.

[0332] In the resist composition of this embodiment, component (B) may be used alone or in combination of two or more types. When the resist composition contains component (B), the content of component (B) in the resist composition is preferably less than 50 parts by mass, more preferably 5 to 45 parts by mass, and even more preferably 10 to 43 parts by mass, per 100 parts by mass of component (A). Setting the content of component (B) within the above preferred range makes it easier to obtain a uniform solution when each component of the resist composition is dissolved in an organic solvent, and thus improves the storage stability of the resist composition, which is preferable.

[0333] <Basic component (D)> In addition to component (A), the resist composition of this embodiment may also contain a basic component (component (D)) that traps the acid generated by exposure (i.e., controls the diffusion of the acid). Component (D) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure in the resist composition. Examples of component (D) include a photo-decayable base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure and loses its acid diffusion control properties, and a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not fall under component (D1). Among these, a photo-decayable base (component (D1)) is preferred because it is easy to improve the characteristics of high sensitivity, roughness reduction, and suppression of the occurrence of coating defects. Component (D1) and component (D2) may be in the form of compounds, incorporated into component (A1) as the above-mentioned constituent unit (a6), or in both forms. The compounds exemplified as component (D1) described later may be used as the acid-generating component (component (B)) mentioned above, depending on their combination with other compounds.

[0334] Regarding component (D1): Component (D1) is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion controllability. Preferably, it is one or more compounds selected from the group consisting of the compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)"), the compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and the compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"). Components (d1-1) to (d1-3) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion controllability (basicity), but they act as quenchers in the unexposed areas of the resist film.

[0335] [In the formula, Rd １ ~Rd ４ Rd in formula (d1-2) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. ２In this example, assume that no fluorine atoms are bonded to the carbon atoms adjacent to the sulfur atom. １ is a single bond or a divalent linking group. m is an integer of 1 or more, M ｍ＋ These are each independently m-valent organic cations.

[0336] {(d1-1) component} ... in the anionic component of formula (d1-1), Rd １ R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of the above R' is... ２０１ Similar examples include Rd １ Preferred substituents are optionally substituted aromatic hydrocarbon groups, optionally substituted aliphatic cyclic groups, or optionally substituted linear alkyl groups. Examples of substituents these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, fluorinated alkyl groups, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), ether bonds, ester bonds, or combinations thereof. When ether bonds or ester bonds are included as substituents, they may be mediated via alkylene groups, and in this case, preferred substituents are the linking groups represented by the general formulas (L-al-1) to (L-al-5). Note that Rd １ If the aromatic hydrocarbon group, aliphatic cyclic group, or linear alkyl group in has a linking group represented by the general formulas (L-al-1) to (L-al-8) as a substituent, then in the general formulas (L-al-1) to (L-al-8), Rd in formula (d1-1) １ The carbon atom constituting the aromatic hydrocarbon group, aliphatic cyclic group, or chain-like alkyl group in the above general formula (L-al-1) to (L-al-8) is bonded to the carbon atom. １０１ The aromatic hydrocarbon group can be preferably a phenyl group, a naphthyl group, or a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and other ring structures). The aliphatic cyclic group can be adamantane, norbornane, isobornane, or tricyclo[5.2.1.0 ２，６It is more preferable that the group is obtained by removing one or more hydrogen atoms from a polycycloalkane such as decane or tetracyclododecane. The chain-like alkyl group is preferably one to ten carbon atoms in number, and specifically, examples include linear alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group; and branched alkyl groups such as 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0337] When the chain-like alkyl group is a fluorinated alkyl group having a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine. Examples of atoms other than fluorine include oxygen atoms, sulfur atoms, nitrogen atoms, and the like.

[0338] The following are preferred specific examples of the anion portion of component (d1-1).

[0339]

[0340] ...In the cation component (d1-1), M ｍ＋ M is an organic cation with an m-valence. ｍ＋ Suitable organic cations include those similar to those represented by the general formulas (ca-1) to (ca-3), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the formulas (ca-1-1) to (ca-1-104) being even more preferred. The (d1-1) component may be used alone or in combination of two or more types.

[0341] {(d1-2) component} ... in the anionic component of formula (d1-2), Rd ２R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. ２０１ Similar examples include the following. However, Rd ２ In this case, the carbon atom adjacent to the S atom is assumed to be unbonded to a fluorine atom (not fluorine-substituted). This results in the anions of components (d1-2) becoming appropriately weak acid anions, improving the quenching ability of component (D). Rd ２ The alkyl group is preferably a chain-like alkyl group which may have substituents, or an aliphatic cyclic group which may have substituents, and more preferably an aliphatic cyclic group which may have substituents.

[0342] The linear alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group may be adamantane, norbornane, isobornane, or tricyclo[5.2.1.0 ２，６ A group obtained by removing one or more hydrogen atoms from decane, tetracyclododecane, etc. (which may have substituents); more preferably a group obtained by removing one or more hydrogen atoms from camphor.

[0343] Rd ２ The hydrocarbon group may have substituents, and such substituents may be Rd of formula (d1-1). １ Examples include substituents similar to those that may be present on hydrocarbon groups (aromatic hydrocarbon groups, aliphatic cyclic groups, and linear alkyl groups) in the above.

[0344] The following are preferred specific examples of the anion portion of component (d1-2).

[0345]

[0346] ...In the cation component formula (d1-2), M ｍ＋ is an m-valent organic cation, and M in formula (d1-1) above. ｍ＋ The same applies. (d1-2) Components may be used individually or in combination of two or more.

[0347] {(d1-3) component} ... in the anionic component of formula (d1-3), Rd３ R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and the R' ２０１ Similar groups are mentioned, and it is preferable that they are cyclic groups containing a fluorine atom, linear alkyl groups, or linear alkenyl groups. Among these, fluorinated alkyl groups are preferred, and the aforementioned Rd １ A fluorinated alkyl group similar to the one shown is more preferable.

[0348] In formula (d1-3), Rd ４ R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. ２０１ Similar examples include alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups, which may have substituents. Rd ４ The alkyl group in is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. ４ Some of the hydrogen atoms in the alkyl group may be substituted with hydroxyl groups, cyano groups, etc. Rd ４ The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms. Specifically, examples of alkoxy groups having 1 to 5 carbon atoms include methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, and tert-butoxy groups. Among these, methoxy and ethoxy groups are preferred.

[0349] Rd ４ The alkenyl group in R' is ２０１ Examples of groups similar to the alkenyl group in the above include vinyl groups, propenyl groups (allyl groups), 1-methylpropenyl groups, and 2-methylpropenyl groups, which are preferred. These groups may further have substituents of an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

[0350] Rd ４ The cyclic group in is R'２０１ Examples of cyclic groups similar to those in [5.2.1.0] include cyclopentane, cyclohexane, adamantane, norbornane, isobornane, and tricyclo[5.2.1.0]. ２，６ A preferred alicyclic group is obtained by removing one or more hydrogen atoms from a cycloalkane such as decane or tetracyclododecane, or an aromatic group such as a phenyl group or naphthyl group. ４ When Rd is an alicyclic group, the resist composition dissolves well in organic solvents, resulting in good lithography properties. ４ When the resist group is an aromatic group, in lithography using EUV or the like as the exposure light source, the resist composition exhibits excellent light absorption efficiency, resulting in good sensitivity and lithographic characteristics.

[0351] In formula (d1-3), Yd １ Yd is a single bond or a divalent linking group. １ The divalent linking group in formula (a2-1) is not particularly limited, but may include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have substituents, and divalent linking groups containing heteroatoms. ２１ Examples of divalent linking groups include divalent hydrocarbon groups that may have substituents, and divalent linking groups containing heteroatoms, as mentioned in the explanation of divalent linking groups in Yd. １ The preferred members are carbonyl groups, ester bonds, amide bonds, alkylene groups, or combinations thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

[0352] The following are preferred specific examples of the anionic portion of components (d1-3).

[0353]

[0354]

[0355] ...In the cation component formula (d1-3), M ｍ＋ is an m-valent organic cation, and M in formula (d1-1) above. ｍ＋The same applies. (d1-3) Components may be used individually or in combination of two or more.

[0356] The component (D1) may be any one of the above components (d1-1) to (d1-3), or two or more may be used in combination. When the resist composition contains component (D1), the content of component (D1) in the resist composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 2 to 15 parts by mass, per 100 parts by mass of component (A).

[0357] Component (D1) preferably contains component (d1-1) as described above. The content of component (d1-1) in the total component (D1) is preferably 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more, and component (D1) may consist only of compound (d1-1).

[0358] Method for producing component (D1): The method for producing components (d1-1) and (d1-2) described above is not particularly limited and can be produced by known methods. The method for producing component (d1-3) is also not particularly limited and can be produced, for example, in the same manner as described in US2012-0149916. As an example of a basic component (component (D)) that traps the acid generated by exposure, the compound of component (D1) is shown, but 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 the compound that generates an acid with lower acidity than the acid generated by the compound of component (D1) upon exposure may be used as component (D). Alternatively, in the resist composition of this embodiment, the compound of component (D1) may be used as component (B), and the component (D2), described later, may be used as component (D).

[0359] Regarding component (D2): Component (D) may contain nitrogen-containing organic compound components that do not fall under component (D1) above (hereinafter referred to as "component (D2)"). Component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not fall under component (D1), 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. An aliphatic amine is an amine having one or more aliphatic groups, and it is preferable that the aliphatic group has 1 to 12 carbon atoms. Examples of aliphatic amines include ammonia (NH) ３ Examples include amines (alkylamines or alkyl alcoholamines) or cyclic amines in which at least one hydrogen atom is substituted with an alkyl group or hydroxyalkyl group having 12 or fewer carbon atoms. Specific examples of alkylamines and alkyl alcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine are particularly preferred.

[0360] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. These heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of aliphatic monocyclic amines include piperidine and piperazine. Aliphatic polycyclic amines with 6 to 10 carbon atoms are preferred, and specific examples include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0361] 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, etc., with triethanolamine triacetate being preferred.

[0362] Furthermore, an aromatic amine may be used as component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tripenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, and 2,6-di-tert-butylpyridine.

[0363] The (D2) component may be used alone or in combination of two or more types. When the resist composition contains the (D2) component, the content of the (D2) component in the resist composition is usually in the range of 0.01 to 5 parts by mass per 100 parts by mass of the (A) component. By using the above range, the resist pattern shape, the stability over time, etc., are improved.

[0364] <At least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxoacids and their derivatives> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxoacids and their derivatives (hereinafter referred to as "component (E)"). Specifically, examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc., with salicylic acid being preferred among them. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, phosphinic acid, etc., with phosphonic acid being particularly preferred among them.

[0365] In the resist composition of this embodiment, component (E) may be used alone or in combination of two or more types. When the resist composition contains component (E), the content of 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 component (A). By setting the content within the above range, the lithography characteristics are further improved.

[0366] <Fluorine Additive Component (F)> The resist composition of this embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") as a hydrophobic resin. Component (F) is used to impart water repellency to the resist film and can improve lithography properties by being used as a resin separate from component (A). As component (F), for example, fluorine-containing polymer compounds described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 can be used. More specifically as component (F), polymers having a constituent unit (f1) represented by the following general formula (f1-1) can be mentioned. The polymer is preferably a polymer (homopolymer) consisting only of a constituent unit (f1) represented by the following formula (f1-1); a copolymer of the constituent unit (f1) and the constituent unit (a1); and more preferably a copolymer of the constituent unit (f1) and a constituent unit derived from acrylic acid or methacrylic acid and the constituent unit (a1). Here, the constituent unit (a1) copolymerized with the constituent unit (f1) is preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, a constituent unit derived from 1-methyl-1-adamantyl (meth)acrylate, and more preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate.

[0367] [In the formula, R is the same as above, Rf １０２ and Rf １０３ Each of these independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf １０２ and Rf １０３ They may be the same or different. １ Rf is an integer between 0 and 5. １０１ It is an organic group containing a fluorine atom.

[0368] In formula (f1-1), R bonded to the carbon atom at the α position is the same as described above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf １０２ and Rf １０３ A fluorine atom is preferred as the halogen atom. Rf １０２ and Rf １０３ Examples of alkyl groups having 1 to 5 carbon atoms in R include those similar to the alkyl groups having 1 to 5 carbon atoms in R above, with methyl or ethyl groups being preferred. １０２ and Rf １０３ Specifically, examples of halogenated alkyl groups having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Fluorine atoms are preferred as the halogen atoms, particularly Rf. １０２ and Rf １０３ Preferably, the atoms are hydrogen atoms, fluorine atoms, or alkyl groups having 1 to 5 carbon atoms; more preferably, hydrogen atoms, fluorine atoms, methyl groups, or ethyl groups; and even more preferably, hydrogen atoms. In formula (f1-1), nf １ x is an integer between 0 and 5, preferably between 0 and 3, and more preferably 1 or 2.

[0369] In formula (f1-1), Rf １０１ The fluorine atom is an organic group containing a fluorine atom, and 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. Furthermore, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferable that 60% or more are fluorinated, as this increases the hydrophobicity of the resist film during immersion exposure. Among these, Rf １０１ More preferably, it is a fluorinated hydrocarbon group having 1 to 6 carbon atoms, a trifluoromethyl group, or -CH ２ -CF ３ ien-CH ２ -CF２ -CF ３ , -CH(CF ３ ) ２ ien-CH ２ -CH ２ -CF ３ ien-CH ２ -CH ２ -CF ２ -CF ２ -CF ２ -CF ３ That is particularly preferable.

[0370] The weight-average molecular weight (Mw) of component (F) (based on polystyrene conversion 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. If it is below the upper limit of this range, it has sufficient solubility in the resist solvent for use as a resist, and if it is above the lower limit of this range, the water repellency of the resist film is good. The dispersion degree (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.

[0371] In the resist composition of this embodiment, component (F) may be used alone or in combination of two or more types. When the resist composition contains component (F), the content of component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of component (A).

[0372] <Organic Solvent Component (S)> The resist composition of this embodiment can be manufactured by dissolving the resist material in an organic solvent component (hereinafter referred to as "component (S)"). In the resist composition of this embodiment, component (S) may be used alone or as a mixture of two or more solvents. Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, ethyl lactate (EL), and cyclohexanone are preferred.

[0373] Furthermore, a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred as component (S). The mixing ratio (mass ratio) can be appropriately determined considering the compatibility between PGMEA and the polar solvent. A mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred as component (S). In this case, the mixing ratio is preferably 70:30 to 95:5 in mass ratio. The amount of component (S) used is not particularly limited and is appropriately set according to the coating thickness at a concentration that can be applied to a substrate, etc. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0374] The resist composition of this embodiment may be subjected to removal of impurities after dissolving the resist material in component (S), using a polyimide porous membrane, a polyamide-imide porous membrane, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous membrane, a filter made of a polyamide-imide porous membrane, or a filter made of a polyimide porous membrane and a polyamide-imide porous membrane. Examples of the polyimide porous membrane and the polyamide-imide porous membrane include those described in Japanese Patent Application Publication No. 2016-155121.

[0375] The resist composition of this embodiment described above contains a polymer having a group represented by general formula (i-1) (end group (i-1)) at at least one end of the main chain. In the resist composition of this embodiment, the end of the main chain of the polymer has a tertiary alkyl ester type acid-dissociable group -C(Rpg １ ) (RPG ２ ) (RPG ３ ) has the acid-dissociating group -C (Rpg １ ) (RPG ２ ) (RPG ３ By introducing the acid-dissociable group -C(Rpg), the solubility of the resist film is improved even with a small exposure dose, which is expected to enable higher sensitivity. １ ) (RPG ２ ) (RPG ３It is presumed that introducing the above-mentioned acid-dissociable group (-C(Rpg)) will improve the contrast at the interface between the exposed and unexposed areas of the resist film and reduce roughness. Secondary alkyl ester type acid-dissociable groups generally have a fast deprotection reaction rate, so there is a possibility that the deprotection reaction will proceed during storage of the resist composition, which may result in poor long-term stability of the resist composition. In addition, acid-dissociable groups having an amide bond have a nitrogen atom that exhibits nucleophilicity, attracting anions such as acid generators, making them prone to decomposition during storage, which may result in poor long-term stability of the resist composition. On the other hand, the above-mentioned acid-dissociable group -C(Rpg) １ ) (RPG ２ ) (RPG ３ It is presumed that this group exhibits superior temporal stability compared to secondary alkyl ester type acid-dissociable groups and acid-dissociable groups having amide bonds. Due to these synergistic effects, it is presumed that the resist composition according to this embodiment can improve sensitivity, roughness, and temporal stability.

[0376] (Second aspect: Method for forming a resist pattern) A method for forming a resist pattern according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition according to the first aspect of the present invention described above, exposing the resist film, and developing the exposed resist film to form a resist pattern. One embodiment of such a resist pattern forming method is, for example, a resist pattern forming method carried out as follows.

[0377] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and a bake (post-application bake (PAB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C, to form a resist film. Next, the resist film is subjected to selective exposure using an exposure apparatus such as an electron beam lithography apparatus or an ArF exposure apparatus, either through exposure via a mask (mask pattern) with a predetermined pattern formed on it or by direct irradiation with an electron beam without a mask pattern, and then a bake (post-exposure bake (PEB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C. Next, the resist film is subjected to a development treatment. In the case of an alkaline development process, an alkaline developer is used, and in the case of a solvent development process, a developer containing an organic solvent (organic developer) is used.

[0378] After development, rinsing is preferably performed. In the case of an alkaline development process, rinsing with pure water is preferred, and in the case of a solvent development process, rinsing with a rinsing solution containing an organic solvent is preferred. In the case of a solvent development process, after the development or rinsing process, the developer or rinsing solution adhering to the pattern may be removed using a supercritical fluid. After development or rinsing, drying is performed. In some cases, baking (post-baking) may be performed after the development process.

[0379] The support material is not particularly limited and can be any conventionally known material, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern has been formed. More specifically, examples include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. As for the wiring pattern material, for example, copper, aluminum, nickel, and gold can be used.

[0380] The wavelength used for exposure is not particularly limited and can be an ArF excimer laser, KrF excimer laser, or F ２This can be carried out using radiation such as excimer lasers, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays. The resist pattern formation method of this embodiment is particularly useful in the step of exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam).

[0381] The method for exposing the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or it may be liquid immersion lithography. Liquid immersion lithography is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is filled in advance with a solvent (liquid immersion medium) having a refractive index greater than that of air, and exposure (immersion exposure) is performed in that state. The liquid immersion medium is preferably a solvent having a refractive index greater than that of air and smaller than that of the resist film to be exposed, and examples include water, fluorine-based inert liquids, silicon-based solvents, hydrocarbon-based solvents, etc. Water is preferably used as the liquid immersion medium.

[0382] Examples of alkaline developers used in the alkaline development process include 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution. The organic solvent contained in the organic developer used in the solvent development process can be any solvent that can dissolve component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specifically, examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0383] Examples of ester 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.

[0384] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0385] Organic developers may contain known additives as needed. Examples of such additives include surfactants. While not particularly limited, surfactants such as ionic or nonionic fluorine-based and / or silicone-based surfactants can be used.

[0386] The development process can be carried out by known development methods, such as immersing the support in developer for a certain period of time (dip method), piling up developer on the surface of the support by surface tension and leaving it still for a certain period of time (paddle method), spraying developer onto the surface of the support (spray method), or continuously dispensing developer onto a support rotating at a constant speed while scanning the developer dispensing nozzle at a constant speed (dynamic dispensing method).

[0387] As the organic solvent contained in the rinsing solution used for rinsing after development in the solvent development process, for example, organic solvents that do not easily dissolve the resist pattern can be appropriately selected and used from among the organic solvents listed as organic solvents used in the organic developer solution. 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 individually or in combination of two or more. They may also be used in mixture with other organic solvents or water.

[0388] Rinsing (cleaning) using a rinsing solution can be carried out by known rinsing methods. Examples of such rinsing methods include continuously applying the rinsing solution onto a support rotating at a constant speed (rotary coating method), immersing the support in the rinsing solution for a certain period of time (dip method), and spraying the rinsing solution onto the surface of the support (spray method).

[0389] According to the resist pattern formation method of this embodiment described above, since the above-mentioned resist composition is used, high sensitivity can be achieved in resist pattern formation, and a resist pattern with a good shape and improved roughness can be formed.

[0390] The resist compositions of the embodiments described above, and the various materials used in the pattern forming methods of the embodiments described above (for example, resist solvents, developers, rinse solutions, anti-reflective film forming compositions, topcoat forming compositions, etc.) are preferably free of impurities such as metals, metal salts containing halogens, acids, alkalis, sulfur atoms, or phosphorus atoms. Examples of metal atom-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of impurities in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0391] (Third aspect: Compound) The compound according to this embodiment is a compound represented by the following general formula (I) (hereinafter also referred to as "compound (I)").

[0392] [wherein Xa １ It is an alkylene group. (Rpg) １ RPG ２ and RPG ３ These are each independently hydrocarbon groups that may have substituents. ２ and RPG ３ These may be joined together to form a ring.

[0393] Compound (I) is the same as compound (I) in the first embodiment. Compound (I) is useful as a chain transfer agent when polymerizing component (A1-0) in the first embodiment.

[0394] (Fourth embodiment: Chain transfer agent) The chain transfer agent according to this embodiment contains compound (I). The chain transfer agent according to this embodiment can be suitably used when polymerizing component (A1-0).

[0395] (Fifth aspect: Polymer) The polymer according to this embodiment is a polymer having a group represented by the following general formula (i-1) at at least one end of the main chain (hereinafter also referred to as "polymer (A1-0)").

[0396] [wherein Xa １ It is an alkylene group. (Rpg) １ RPG ２ and RPG ３ These are each independently hydrocarbon groups that may have substituents. ２ and RPG ３ These may be joined together to form a ring.

[0397] Polymer (A1-0) is the same as component (A1-0) in the first embodiment described above. Polymer (A1-0) is useful as a base component of the resist composition.

[0398] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0399] (Example of chain transfer agent synthesis 1: Synthesis of chain transfer agent (Z1-1)) 20.0 g of compound (m01-1), 21.8 g of compound (m02-1), 38.7 g of 1,1'-carbonyldiimidazole, and 100 g of dimethylformamide (DMF) were placed in a three-twin flask and stirred at 60°C for 4 hours. After the reaction mixture was cooled to room temperature, 100 g of n-heptane was added and washed four times with 100 g of deionized water. The organic layer was concentrated and dried under reduced pressure to obtain 25.7 g of chain transfer agent (Z1-1).

[0400]

[0401] The obtained chain transfer agent (Z1-1) was subjected to NMR measurement, and its structure was identified based on the following results.

[0402] Chain transfer agent (Z1-1): δ (ppm) = 1.39 (3H, s), 1.50 (1H, s), 1.69 (8H, m), 3.52 (2H, s)

[0403] (Examples 2-5 of chain transfer agent synthesis: Chain transfer agents (Z1-2) to (Z1-5) were synthesized in the same manner as in chain transfer agent synthesis example 1, except that compound (m02-2), compound (m02-3), compound (m02-4), or compound (m02-5) was used instead of compound (m02-1) of the chain transfer agents (Z1-2) to (Z1-5).

[0404]

[0405]

[0406] The obtained chain transfer agents (Z1-2) to (Z1-5) were subjected to NMR measurements, and their structures were identified based on the following results.

[0407] Chain transfer agent (Z1-2): δ (ppm) = 1.39 (3H, s), 1.50 (1H, s), 1.67 (10H, m), 3.52 (2H, m)

[0408] Chain transfer agent (Z1-3): δ (ppm) = 0.90 (3H, s), 1.49 (2H, q), 1.50 (1H, s), 1.69 (8H, m), 3.52 (2H, m)

[0409] Chain transfer agent (Z1-4): δ (ppm) = 1.50 (1H, s), 1.75 (8H, m), 3.52 (2H, s), 5.28 (1H, s), 5.29 (1H, s), 5.89 (1H, m)

[0410] Chain transfer agent (Z1-5): δ (ppm) = 1.50 (1H, s), 1.61 (6H, s), 3.52 (2H, s), 7.09 (2H, d), 7.26 (2H, d)

[0411] (Example 6 of chain transfer agent synthesis: The chain transfer agent (Z1-6) was synthesized in the same manner as in Example 1 of chain transfer agent synthesis, except that compound (m01-2) was used instead of compound (m01-1) of the chain transfer agent (Z1-6).

[0412]

[0413]

[0414] The obtained chain transfer agent (Z1-6) was subjected to NMR measurement, and its structure was identified based on the following results.

[0415] Chain transfer agent (Z1-6): δ (ppm) = 1.39 (3H, s), 1.40 (1H, s), 1.69 (8H, m), 2.51 (2H, t), 2.95 (2H, t)

[0416] (Example of polymer compound synthesis 1: Synthesis of polymer compound (A1-1)) 13.2 g of compound (a10-1pre), 11.6 g of compound (a1-1m), 2.2 g of polymerization initiator azobis(isobutyrate)dimethyl (V-601), and 1.6 g of compound (Z1-1) as a chain transfer agent were dissolved in 130 g of methyl ethyl ketone (MEK), heated to 70°C under a nitrogen atmosphere, and stirred for 5 hours. Then, 4.2 g of acetic acid and 80 g of methanol (MeOH) were added to the reaction solution, and a deprotection reaction was carried out at 30°C for 18 hours. After the reaction was complete, the obtained reaction solution was precipitated in 600 g of heptane and washed. The obtained white solid was filtered and dried under reduced pressure overnight to obtain the target copolymer (A1-1).

[0417]

[0418] (Examples 2-6 of polymer compound synthesis: Polymer compounds (A1-2) to (A1-6) were obtained in the same manner as in polymer compound synthesis example 1, except that chain transfer agents (Z1-2) to (Z1-6) were used instead of chain transfer agent (Z1-1).)

[0419]

[0420] (Examples 7-11 of polymer compound synthesis: Polymer compounds (A1-6) to (A1-10) were obtained in the same manner as in Polymer Compound Synthesis Example 1, except that the synthetic compounds (a1-2m), (a1-3m), (a1-4m), (a5-1m), and (a6-1m) of polymer compounds (A1-7) to (A1-11) were used.)

[0421]

[0422] For the obtained polymer compounds (A1-1) to (A1-11), the copolymerization composition ratio (the proportion (molar ratio) of each constituent unit in the structural formula) was determined by carbon-13 nuclear magnetic resonance spectroscopy (150 MHz, １３ The results were obtained by C-NMR. The results are shown in Table 1.

[0423]

[0424] <Preparation of Resist Compositions> (Examples 1-13, Comparative Examples 1-2) The components shown in Table 2 were mixed and dissolved to prepare the resist compositions for each example.

[0425]

[0426] In Table 2, each abbreviation has the following meaning. The numbers in [ ] represent the amount (parts by mass). (A1)-1 to (A1)-11: The above polymer compounds (A1-1) to (A1-11). (A2)-1: The following polymer compound (A2-1). (A2)-2: The following polymer compound (A2-2). For polymer compounds (A2-1) to (A2-2), the copolymerization composition ratio (the proportion (molar ratio) of each constituent unit in the structural formula) is measured using the carbon-13 nuclear magnetic resonance spectrum (150 MHz, １３ The results were obtained by C-NMR. The results are shown in Table 1.

[0427]

[0428] (B)-1: An acid generator consisting of the following compound (B-1). (B)-2: An acid generator consisting of the following compound (B-2).

[0429]

[0430] (D)-1: An acid diffusion control agent consisting of the following compound (D-1). (D)-2: An acid diffusion control agent consisting of the following compound (D-2).

[0431]

[0432] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0433] <Formation of Resist Pattern> Each resist composition was applied to an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS) using a spinner. A pre-bake (PAB) treatment was performed on a hot plate at 110°C for 60 seconds, followed by drying to form a resist film with a thickness of 50 nm. Next, the resist film was subjected to drawing (exposure) using an electron beam lithography system JEOL JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100 kV, with a target size of a 1:1 line-and-space pattern (hereinafter referred to as "LS pattern") with a line width of 50 nm. Subsequently, a post-exposure heating (PEB) treatment was performed at 100°C for 60 seconds. Then, alkaline development was performed at 23°C for 60 seconds using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). After that, a water rinse was performed with pure water for 15 seconds. As a result, a 1:1 LS pattern with a line width of 50 nm was formed.

[0434] [Evaluation of Optimal Exposure Dose (Eop)] The optimal exposure dose Eop (μC / cm²) for forming a target-sized LS pattern through the above <Formation of Resist Pattern> process. ２ We calculated this as "Eop(μC / cm²)". ２ This is shown in Table 3.

[0435] [Evaluation of LWR (Line-Wide Roughness)] For the LS pattern formed in the above <Formation of Resist Pattern>, 3σ, a measure of LWR, was determined. This is shown in Table 3 as "LWR (nm)". "3σ" represents three times the standard deviation (σ) (unit: nm) obtained from the measurement results of 400 line positions measured in the longitudinal direction of the line using a scanning electron microscope (acceleration voltage 800V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). The smaller the value of 3σ, the smaller the roughness of the line sidewalls, and the more uniform the width of the LS pattern obtained.

[0436] [Evaluation of LWR over time (ΔLWR)] The resist composition was left standing at -20°C for 3 weeks and stored. Eop was determined in the same manner as in the [Evaluation of optimal exposure (Eop)] above. The difference between the LWR of the line pattern at Eop (LWR1) and the LWR of the line pattern of the resist composition stored at 40°C for 3 weeks at the same exposure (LWR2) is expressed as "ΔLWR over 3 weeks (nm)" and is shown in Table 3. ΔLWR = LWR1 - LWR2

[0437]

[0438] The results shown in Table 3 confirm that the resist composition of the example was superior to the resist composition of the comparative example in terms of sensitivity, LWR, and ΔLWR.

[0439] While preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications are possible without departing from the spirit of the invention. The present invention is not limited by the foregoing description, but only by the scope of the appended claims.

Claims

A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, It contains a resin component whose solubility in the developing solution changes due to the action of acid. A resist composition wherein the resin component contains a polymer having a group represented by the following general formula (i-1) at at least one end of the main chain. [wherein Xa １ It is an alkylene group. (Rpg) １ , RPG ２ and RPG ３ These are each independently hydrocarbon groups that may have substituents. ２ and RPG ３ These may be joined together to form a ring. In the general formula (i-1), -C(Rpg １ )(Rpg ２ )(Rpg ３ ) is a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2), a group represented by the following general formula (a1-r2-3), or a group represented by the following general formula (a1-r2-4). The resist composition according to claim 1. [In formula (a1-r2-1), Ra' １０ This represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups. １１ Ra' １０ This indicates a group that forms an aliphatic cyclic group together with the bonded carbon atom. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that 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 Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. Ra １０１ ~Ra １０３ Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ is an aromatic hydrocarbon group which may have substituents. In formula (a1-r2-4), Ra' １２ and Ra' １３ Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' １４ This is a hydrocarbon group that may have substituents. * indicates a bond. A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using the resist composition described in claim 1; exposing the resist film; and developing the exposed resist film to form a resist pattern. 　 A compound represented by the following general formula (I). [wherein Xa １ It is an alkylene group. (Rpg) １ , RPG ２ and RPG ３ These are each independently hydrocarbon groups that may have substituents. ２ and RPG ３ These may be joined together to form a ring. In the general formula (I), -C(Rpg １ ) (RPG ２ ) (RPG ３ The compound according to claim 4, wherein the group is represented by the following general formula (a1-r2-1), the following general formula (a1-r2-2), the following general formula (a1-r2-3), or the following general formula (a1-r2-4). [In formula (a1-r2-1), Ra' １０ This represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups. １１ Ra' １０ This indicates a group that forms an aliphatic cyclic group together with the bonded carbon atom. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that 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 Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. Ra １０１ ~Ra １０３ Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ is an aromatic hydrocarbon group which may have substituents. In formula (a1-r2-4), Ra' １２ and Ra' １３ Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' １４ This is a hydrocarbon group that may have substituents. * indicates a bond. 　 A chain transfer agent comprising the compound described in claim 4. 　 A polymer having a group represented by the following general formula (i-1) at at least one end of the main chain. [wherein Xa １ It is an alkylene group. (Rpg) １ , RPG ２ and RPG ３ These are each independently hydrocarbon groups that may have substituents. ２ and RPG ３ These may be joined together to form a ring. In the general formula (i-1), -C(Rpg １ ) (RPG ２ ) (RPG ３ The polymer according to claim 7, wherein the group is a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2), a group represented by the following general formula (a1-r2-3), or a group represented by the following general formula (a1-r2-4). [In formula (a1-r2-1), Ra' １０ This represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups. １１ Ra' １０ This indicates a group that forms an aliphatic cyclic group together with the bonded carbon atom. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that 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 Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. Ra １０１ ~Ra １０３ Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ is an aromatic hydrocarbon group which may have substituents. In formula (a1-r2-4), Ra' １２ and Ra' １３ Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' １４ This is a hydrocarbon group that may have substituents. * indicates a bond.

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