Resist composition, resist pattern forming method, compound, acid generator, and acid diffusion control agent

Abstract

The present invention provides, for example, a resist composition which has high sensitivity, and in which the occurrence of a defect is suppressed. The present invention employs a resist composition which generates an acid upon exposure to light, and the solubility of which in a developer solution is changed by the action of an acid, the resist composition containing: a base material component (A), the solubility of which in a developer solution is changed by the action of an acid; and a compound (C) which is represented by general formula (c0) and generates an acid upon exposure to light. In general formula (c0), X01 is an electron withdrawing group. j is an integer of 1 to 5, and X01 is coupled at least at an ortho position or a meta position. In cases where j is an integer of 2 or more, a plurality of X01 moieties may be the same as or different from each other. R01 is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. Xc- represents a counter anion.

Description

Resist composition, method of forming a resist pattern, compound, acid generator, and acid diffusion controller

[0001] The present invention relates to a resist composition, a method for forming a resist pattern, a compound, an acid generator, and an acid diffusion controller. This application claims priority based on Japanese Patent Application No. 2024-070459, filed on April 24, 2024, the contents of which are incorporated herein by reference.

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

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

[0004] In chemically amplified resist compositions, a resin having a specific structural unit is generally used as a base component to improve lithography properties, etc. Furthermore, in resist pattern formation, the behavior of the acid generated from the acid generator component upon exposure is also considered to be a factor that significantly affects lithography properties. A wide variety of acid generators have been proposed for use in chemically amplified resist compositions. For example, onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators are known.

[0005] For example, Patent Document 1 discloses a resist composition that employs a compound containing a sulfonium cation as an acid generator.

[0006] Japanese Patent Application Laid-Open No. 2020-085916

[0007] As resist patterns become finer, for example, in EUV and EB lithography, the goal is to form fine patterns of several tens of nanometers. As patterns become finer, resist materials are required to not only improve various lithography properties but also suppress the occurrence of defects (surface imperfections).

[0008] Here, "defects" refers to all problems detected when a developed resist pattern is observed from directly above using, for example, a surface defect observation device manufactured by KLA-Tencor Corporation (product name "KLA") These defects include, for example, defects caused by the adhesion of foreign matter or precipitates to the surface of the resist pattern after development, such as scum (resist residue), bubbles, or dust, defects related to the pattern shape, such as bridges between line patterns or filling of holes in a contact hole pattern, and color unevenness of the pattern.

[0009] As resist patterns become finer, it is becoming increasingly necessary to simultaneously improve sensitivity and suppress the occurrence of defects.

[0010] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a resist composition that exhibits high sensitivity and suppresses the generation of defects during resist pattern formation, a method of forming a resist pattern that uses the resist composition, and compounds that are useful as acid generators and acid diffusion controller components for use in the resist composition.

[0011] In order to solve the above problems, the present invention employs the following configuration: That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; and a compound (C) that generates an acid upon exposure and is represented by the following general formula (c0):

[0012] [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent. － represents a counter anion.

[0013] A second aspect of the present invention is a method of forming a resist pattern, comprising the steps of forming a resist film on a support using the resist composition related to the first aspect, exposing the resist film to light, and developing the exposed resist film to form a resist pattern.

[0014] A third aspect of the present invention is a compound represented by the following general formula (c0):

[0015] [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent. － represents a counter anion.

[0016] A fourth aspect of the present invention is an acid generator comprising the compound according to the third aspect.

[0017] A fifth aspect of the present invention is an acid diffusion controller comprising the compound according to the third aspect.

[0018] According to the present invention, it is possible to provide a resist composition that exhibits high sensitivity and suppresses the generation of defects during resist pattern formation, a method of forming a resist pattern that uses the resist composition, and compounds that are useful as acid generators and acid diffusion controller components for use in the resist composition.

[0019] In this specification and claims, "aliphatic" is a relative concept to aromatic, and is defined as meaning a group, compound, etc. that does not have aromaticity. "Alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups, unless otherwise specified. The same applies to alkyl groups in alkoxy groups. "Alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups, unless otherwise specified. "Halogen atom" includes fluorine, chlorine, bromine, and iodine atoms. "Structural unit" means a monomer unit that constitutes a polymer compound (resin, polymer, copolymer). When describing "may have a substituent," it refers to cases where a hydrogen atom (-H) is replaced with a monovalent group, and cases where a methylene group (-CH ２ The term "exposure" encompasses both cases where the radical (-) is substituted with a divalent group.

[0020] An "acid-decomposable group" is a group having acid decomposability in which at least a part of the bond in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases by the action of an acid include groups that decompose by the action of an acid to generate a polar group. Examples of polar groups include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO ３ More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, groups in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0021] The term "acid-dissociable group" refers to either (i) a group having acid dissociability in which the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group in which a portion of the bond is cleaved by the action of an acid, followed by a decarboxylation reaction, in which the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved. The acid-dissociable group constituting the acid-decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid-dissociable group. Thus, when the acid-dissociable group is dissociated by the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, thereby increasing the polarity. As a result, the polarity of the entire component (A1) increases. The increase in polarity relatively changes the solubility in the developer, increasing the solubility when the developer is an alkaline developer and decreasing the solubility when the developer is an organic developer.

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

[0023] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. In the "acrylic acid ester", the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent (R αｘ ) is an atom or group other than a hydrogen atom. αｘ ) is substituted with a substituent containing an ester bond, or αｘThis also includes α-hydroxyacrylic esters in which the α-position carbon atom of an acrylic ester is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group. Unless otherwise specified, the α-position carbon atom of an acrylic ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, acrylic esters in which the hydrogen atom bonded to the α-position carbon atom has been replaced with a substituent may be referred to as α-substituted acrylic esters.

[0024] The term "derivative" is used to refer to a compound in which the hydrogen atom at the α-position of the target compound has been substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include a compound in which the hydrogen atom of the hydroxyl group of a target compound in which the hydrogen atom at the α-position may be substituted with a substituent has been substituted with an organic group; a compound in which the hydrogen atom at the α-position of the target compound may be substituted with a substituent to which a substituent other than a hydroxyl group is bonded; and the like. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. Examples of substituents that can be used to replace the hydrogen atom at the α-position of hydroxystyrene include R αｘ The same can be mentioned.

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

[0026] (Resist Composition) The resist composition of this embodiment generates an acid upon exposure, and its solubility in a developer changes due to the action of the acid. This resist composition contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of an acid, and a compound (C) represented by general formula (c0) that generates an acid upon exposure. The compound (C) may be a component whose solubility in a developer changes due to the action of an acid. The compound (C) may be an acid generator component (B) (hereinafter also referred to as "component (B)") that generates an acid upon exposure. The compound (C) may be an acid diffusion controller component (D) (hereinafter also referred to as "component (D)") that traps the acid generated upon exposure (i.e., controls the diffusion of the acid). The resist composition of this embodiment also includes an embodiment in which the compound (C) is used as the base component (A).

[0027] In the resist composition of this embodiment, the component (A) may generate an acid upon exposure, or an additive component formulated separately from the component (A) may generate an acid upon exposure. Specifically, the resist composition of this embodiment may further contain (1) an acid generator component (B) (hereinafter referred to as "component (B)") that generates an acid upon exposure; (2) the component (A) may be a component that generates an acid upon exposure; or (3) the component (A) may be a component that generates an acid upon exposure and further contain component (B). That is, in the cases of (2) and (3) above, the component (A) is a "base component that generates an acid upon exposure and whose solubility in a developer is changed by the action of the acid." When the component (A) is a base component that generates an acid upon exposure and whose solubility in a developer is changed by the action of the acid, the component (A1), described below, is preferably a resin that generates an acid upon exposure and whose solubility in a developer is changed by the action of the acid. As such a resin, a polymer compound having a structural unit that generates an acid upon exposure can be used. The structural unit that generates acid upon exposure may be the structural unit (a5) described below.

[0028]

[0043] When a resist film is formed using the resist composition of this embodiment and the resist film is subjected to selective exposure, for example, an acid is generated from the component (B) in the exposed areas of the resist film, and the solubility of the component (A) in a developer changes due to the action of the acid, whereas the solubility of the component (A) in a developer does not change in the unexposed areas of the resist film, resulting in a difference in solubility in a developer between the exposed and unexposed areas. Therefore, when the resist film is developed, if the resist composition is positive, the exposed areas of the resist film are dissolved and removed, forming a positive resist pattern, whereas if the resist composition is negative, the unexposed areas of the resist film are dissolved and removed, forming a negative resist pattern.

[0029] The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Furthermore, the resist composition of this embodiment may be for use in an alkaline development process in which an alkaline developer is used in the development treatment during resist pattern formation, or for use in a solvent development process in which a developer containing an organic solvent (organic developer) is used in the development treatment.

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

[0031] In the resist composition of this embodiment, as the component (A), one type of compound may be used, or two or more types may be used in combination.

[0032] Regarding the Component (A1): The component (A1) is a resin component whose solubility in a developer changes under the action of an acid. The component (A1) preferably contains a structural unit (a1) containing an acid-decomposable group whose polarity increases under the action of an acid. The component (A1) may contain other structural units in addition to the structural unit (a1), as necessary.

[0033] <<Structural Unit (a1)>> The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases when acted upon by an acid.

[0034] Examples of the acid-dissociable group include those that have been proposed as acid-dissociable groups for base resins of chemically amplified resist compositions. Specific examples of acid-dissociable groups that have been proposed as acid-dissociable groups for base resins of chemically amplified resist compositions include the "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," "tertiary alkyloxycarbonyl acid-dissociable groups," and "secondary alkyloxycarbonyl acid-dissociable groups" described below.

[0035] Acetal-Type Acid-Dissociable Group: Among the polar groups, examples of the acid-dissociable group that protects a carboxy group or a hydroxyl group include acid-dissociable groups represented by the following general formula (a1-r-1) (hereinafter, sometimes referred to as "acetal-type acid-dissociable group"):

[0036] [In the formula, Ra' １ , Ra' ２ is a hydrogen atom or an alkyl group. ３ is a hydrocarbon group, and Ra' ３ is Ra' １ , Ra' ２ may be bonded to any one of the following to form a ring.]

[0037] In formula (a1-r-1), Ra' １ and Ra' ２ Among Ra', at least one is preferably a hydrogen atom, and more preferably both are hydrogen atoms. １ or Ra' ２When is an alkyl group, examples of the alkyl group include the same alkyl groups as those exemplified as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester above, and alkyl groups having 1 to 5 carbon atoms are preferred. Specific examples include linear or branched alkyl groups. More specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. A methyl group or an ethyl group is more preferred, and a methyl group is particularly preferred.

[0038] In formula (a1-r-1), Ra' ３ Examples of the hydrocarbon group include a linear or branched alkyl group, and a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Of these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0039] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0040] Ra' ３When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As an aliphatic hydrocarbon group that is a monocyclic group, a group in which one hydrogen atom has been removed from a monocycloalkane is preferred. As the monocycloalkane, one having 3 to 6 carbon atoms is preferred, and specific examples thereof include cyclopentane and cyclohexane. As an aliphatic hydrocarbon group that is a polycyclic group, a group in which one hydrogen atom has been removed from a polycycloalkane is preferred, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferred, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ]decane, tetracyclododecane, and the like.

[0041] Ra' ３ When the cyclic hydrocarbon group described above becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Ra' ３Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (an aryl group or a heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0042] Ra' ３ The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R Ｐ１ , -R Ｐ２ -O-R Ｐ１ , -R Ｐ２ -CO-R Ｐ１ , -R Ｐ２ -CO-OR Ｐ１ , -R Ｐ２ -O-CO-R Ｐ１ , -R Ｐ２ -OH, -R Ｐ２ -CN or -R Ｐ２ —COOH (hereinafter, these substituents are also collectively referred to as “Rax5”). Ｐ１ is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Ｐ２ is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Ｐ１ and R Ｐ２Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group, and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of one type of the above-mentioned substituents, or may have one or more of each of two or more types of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl; 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. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0043] Ra' ３ But Ra' １ , Ra' ２ When the cyclic group is bonded to any one of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0044] Tertiary alkyl ester acid-dissociable group: Among the above polar groups, examples of the acid-dissociable group protecting the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2): Of the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group will hereinafter be referred to as "tertiary alkyl ester acid-dissociable groups" for convenience.

[0045] [In the formula, Ra' ４ ~Ra'６ are each a hydrocarbon group, and Ra' ５ , Ra' ６ may be bonded to each other to form a ring.

[0046] Ra' ４ Examples of the hydrocarbon group of Ra' include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. ４ The linear or branched alkyl group and the cyclic hydrocarbon group (a monocyclic aliphatic hydrocarbon group, a polycyclic aliphatic hydrocarbon group, and an aromatic hydrocarbon group) in ３ The same as Ra' can be mentioned. ４ The chain or cyclic alkenyl group in Ra' is preferably an alkenyl group having 2 to 10 carbon atoms. ５ , Ra' ６ The hydrocarbon group of Ra' ３ The same can be mentioned.

[0047] Ra' ５ and Ra' ６ When Ra' is bonded to each other to form a ring, preferred examples thereof include a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2), and a group represented by the following general formula (a1-r2-3). ４ ~Ra' ６ When the groups are not bonded to each other and are independent hydrocarbon groups, preferred examples include groups represented by the following general formula (a1-r2-4).

[0048] [In formula (a1-r2-1), Ra' １０ represents a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group. １１ is Ra' １０ represents a group which forms an aliphatic cyclic group together with the carbon atom to which it is bonded. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group which forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra １０１ ~Ra １０３are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. １０１ ~Ra １０３ Two or more of the above may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ In formula (a1-r2-4), Ra′ is an aromatic hydrocarbon group which may have a substituent. １２ and Ra' １３ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms of this chain saturated hydrocarbon group may be substituted. １４ is a hydrocarbon group which may have a substituent. * indicates a bond (the same applies hereinafter).

[0049] In the above formula (a1-r2-1), Ra' １０ is a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group.

[0050] Ra' １０ The linear alkyl group in Ra' has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. １０ In the formula (I), the branched alkyl group is the above-mentioned Ra' ３ The same can be mentioned.

[0051] Ra' １０In the above, the alkyl group may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Furthermore, some of the carbon atoms (such as methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -S-, and -S(=O) ２ -, -S(=O) ２ -O- and the like.

[0052] In formula (a1-r2-1), Ra' １１ (Ra' １０ The aliphatic cyclic group formed together with the carbon atom to which Ra' is bonded in formula (a1-r-1) is ３ Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl and cyclohexyl groups are more preferred.

[0053] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the formula (a1-r-1). ３ Examples of the cyclic hydrocarbon group include a group in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in the formula (I). The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of the substituent include the above-mentioned Ra' ３ In formula (a1-r2-2), the substituents that the cyclic hydrocarbon group in formula (a1-r2-2) may have are the same as those in formula (a1-r2-2). １０１ ~Ra １０３ In the formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. １０１ ~Ra １０３In the above formula, examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, and cyclododecyl group; ２，６ ]decanyl group, tricyclo[3.3.1.1 ３，７ ] decanyl group, tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] and polycyclic aliphatic saturated hydrocarbon groups such as a dodecanyl group and an adamantyl group. １０１ ~Ra １０３ Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom is particularly preferable.

[0054] The above Ra １０１ ~Ra １０３ Examples of the substituents that the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the formula (I) include the above-mentioned Ra ｘ５ The same groups as those shown below can be mentioned.

[0055] Ra １０１ ~Ra １０３ Examples of the group containing a carbon-carbon double bond formed by two or more of the above being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidene-ethenyl group, a cyclohexylidene-ethenyl group, etc. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0056] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). ３ In formula (a1-r2-3), the groups exemplified as the aliphatic hydrocarbon group are preferably monocyclic or polycyclic groups. １０４Examples of the aromatic hydrocarbon group in the formula (I) include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. １０４ is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0057] Ra in formula (a1-r2-3) １０４ Examples of the substituent that may be possessed by the group include a methyl group, an ethyl group, a propyl group, a hydroxy group, a carboxy group, a halogen atom, an alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group), an alkyloxycarbonyl group, and the like.

[0058] In formula (a1-r2-4), Ra' １２ and Ra' １３ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. １２ and Ra' １３ In the formula (I), the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned Ra １０１ ~Ra １０３ The monovalent saturated chain hydrocarbon group having 1 to 10 carbon atoms in the formula (1) may be substituted in part or in whole. １２ and Ra' １３ Among these, Ra' is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group. １２ and Ra' １３ In the case where the chain saturated hydrocarbon group represented by the formula: ｘ５ The same groups as those shown below can be mentioned.

[0059] In formula (a1-r2-4), Ra' １４is a hydrocarbon group which may have a substituent. １４ The hydrocarbon group in the formula (I) includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0060] Ra' １４ The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Of these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0061] Ra' １４ The branched alkyl group in the formula (I) preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0062] Ra' １４ When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As an aliphatic hydrocarbon group that is a monocyclic group, a group in which one hydrogen atom has been removed from a monocycloalkane is preferred. As the monocycloalkane, one having 3 to 6 carbon atoms is preferred, and specific examples thereof include cyclopentane and cyclohexane. As an aliphatic hydrocarbon group that is a polycyclic group, a group in which one hydrogen atom has been removed from a polycycloalkane is preferred, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferred, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ]decane, tetracyclododecane, and the like.

[0063] Ra' １４ As the aromatic hydrocarbon group in １０４ Among them, the aromatic hydrocarbon groups Ra' are the same as those in １４is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. １４ Examples of the substituent that may be possessed by Ra include １０４ Examples of the substituents include the same as those that may be possessed by the group.

[0064] Ra' in formula (a1-r2-4) １４ When Ra' in formula (a1-r2-4) is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. １４ When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be any one of the 1st, 2nd, and 9th positions of the anthryl group.

[0065] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0066]

[0067]

[0068]

[0069] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0070]

[0071]

[0072]

[0073] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0074]

[0075] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0076]

[0077] Tertiary alkyloxycarbonyl acid dissociable group: Examples of the acid dissociable group that protects the hydroxyl group of the polar group include acid dissociable groups represented by the following general formula (a1-r-3) (hereinafter, for convenience, may be referred to as "tertiary alkyloxycarbonyl acid dissociable group").

[0078] [In the formula, Ra' ７ ~Ra' ９ are each an alkyl group.

[0079] In formula (a1-r-3), Ra' ７ ~Ra' ９ are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms. The total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0080] Secondary Alkyl Ester-Type Acid-Dissociable Group: Among the above polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-4).

[0081] [In the formula, Ra' １０ is a hydrocarbon group. １１ａ and Ra' １１ｂ are each independently a hydrogen atom, a halogen atom or an alkyl group. １２ is a hydrogen atom or a hydrocarbon group. １０ and Ra' １１ａ or Ra' １１ｂ and may be bonded to each other to form a ring. １１ａ or Ra' １１ｂ and Ra' １２ may be bonded to each other to form a ring.

[0082] In the formula, Ra' １０ and Ra' １２The hydrocarbon group in Ra' is ３ In the formula, Ra' １１ａ and Ra' １１ｂ The alkyl group in Ra' is １ In the formula, Ra' is the same as the alkyl group in １０ and Ra' １２ and the hydrocarbon group in Ra' １１ａ and Ra' １１ｂ The alkyl group in may have a substituent. Examples of the substituent include the above-mentioned Ra ｘ５ etc.

[0083] Ra' １０ and Ra' １１ａ or Ra' １１ｂ may be bonded to each other to form a ring. The ring may be polycyclic or monocyclic, and may be an alicyclic or aromatic ring. The alicyclic and aromatic rings may contain heteroatoms.

[0084] Ra' １０ and Ra' １１ａ or Ra' １１ｂ and are bonded to each other to form a ring, among the above, a monocycloalkene, a ring in which a portion of the carbon atoms of a monocycloalkene is substituted with a heteroatom (such as an oxygen atom or a sulfur atom), or a monocycloalkadiene is preferred, a cycloalkene having 3 to 6 carbon atoms is preferred, and cyclopentene or cyclohexene is preferred.

[0085] Ra' １０ and Ra' １１ａ or Ra' １１ｂ The ring formed by bonding these may be a fused ring. Specific examples of such a fused ring include indan.

[0086] Ra' １０ and Ra' １１ａ or Ra' １１ｂ The ring formed by bonding together may have a substituent. Examples of the substituent include the above-mentioned Ra ｘ５ etc.

[0087] Ra' １１ａor Ra' １１ｂ and Ra' １２ and may be bonded to each other to form a ring, and the ring may include Ra' １０ and Ra' １１ａ or Ra' １１ｂ and the ring formed by bonding with each other are exemplified.

[0088] Specific examples of the group represented by the formula (a1-r-4) are listed below.

[0089]

[0090] Examples of the structural unit (a1) include a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, a structural unit derived from acrylamide, a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least some of the hydrogen atoms in the hydroxyl groups are protected with a substituent containing the above-mentioned acid-decomposable group, and a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative in which at least some of the hydrogen atoms in -C(═O)-OH are protected with a substituent containing the above-mentioned acid-decomposable group.

[0091] Of the above, the structural unit (a1) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. Preferred specific examples of such structural unit (a1) include structural units represented by the following general formulas (a1-1), (a1-2), and (a1-3):

[0092] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. １ is a divalent hydrocarbon group which may have an ether bond. ａ１ is an integer from 0 to 2. １ is an acid-dissociable group represented by the above general formula (a1-r-1), (a1-r-2) or (a1-r-4). １ is (n ａ２ +1) valent hydrocarbon group. ａ２ is an integer from 1 to 3.２ represents an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3). ００１ represents a single bond or a divalent linking group. ０１ is a single bond or a divalent linking group. ０１ is an acid-dissociable group represented by the above general formula (a1-r-1), (a1-r-2) or (a1-r-4). ０１ is an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxy group, or an alkoxy group; q is an integer of 0 to 3; and n is an integer of 0 or greater, provided that n≦q×2+4.

[0093] In the formulas (a1-1) to (a1-3), the alkyl group having 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. A fluorine atom is particularly preferred as the halogen atom. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the perspective of industrial availability, a hydrogen atom or a methyl group is most preferred.

[0094] In the formula (a1-1), Va １ The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0095] Va １ The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specific examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0096] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0097] Examples of the aliphatic hydrocarbon group containing a ring in its structure include alicyclic hydrocarbon groups (groups in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. A preferred monocyclic alicyclic hydrocarbon group is a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ]decane, tetracyclododecane, and the like.

[0098] Va １The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (an arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (an aryl group) has been substituted with an alkylene group (for example, a group in which one further hydrogen atom has been removed from the aryl group of an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 or 2, and particularly preferably 1.

[0099] In the formula (a1-1), Ra １ is preferably an acid-dissociable group represented by the above general formula (a1-r-2) or (a1-r-4), and among these, a group represented by the general formula (a1-r2-1) or an acid-dissociable group represented by the general formula (a1-r-4) is more preferred.

[0100] In the formula (a1-2), Wa １ (n ａ２The (+1)-valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, but is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in the structure, and groups that combine linear or branched aliphatic hydrocarbon groups with aliphatic hydrocarbon groups containing a ring in the structure. ａ２ The valence of Ra is preferably 2 to 4, more preferably 2 or 3. ２ is preferably an acid-dissociable group represented by the above general formula (a1-r-1).

[0101] In the formula (a1-3), Ya ００１ The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. ００１ is preferably 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 alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. Among these, Ya ００１ The alkyl group is preferably a combination of an ester bond [—C(═O)—O—, —O—C(═O)—] and a linear alkylene group, or a single bond, and more preferably a single bond.

[0102] In the formula (a1-3), Ya ０１ The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. ０１Among the above, it is preferable that Ya 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. ０１ The alkyl group is preferably a combination of an ester bond [—C(═O)—O—, —O—C(═O)—] and a linear alkylene group, or a single bond, and more preferably a single bond.

[0103] In the formula (a1-3), Rax ０１ is preferably an acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4), and among these, an acid dissociable group represented by the general formula (a1-r-2) is more preferred, and a group represented by the general formula (a1-r2-1) is even more preferred.

[0104] In the formula (a1-3), Rz ０１ The alkyl group, halogenated alkyl group, and alkoxy group in Rz preferably have 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, halogenated alkyl group, and alkoxy group may be linear or branched. ０１ The halogen atom in Rz is preferably an iodine atom. ０１ The halogen atom of the halogenated alkyl group in Rz is preferably a fluorine atom, an iodine atom, or a bromine atom, and more preferably a fluorine atom. ０１ As the alkyl group, an alkoxy group or a hydroxy group is preferred, and a hydroxy group is more preferred.

[0105] In the formula (a1-3), q is an integer of 0 to 3. When q is 0, the structure is a benzene structure, when q is 1, the structure is a naphthalene structure, when q is 2, the structure is an anthracene structure, and when q is 3, the structure is a tetracene structure. In the formula (a1-3), n is an integer of 0 or more, preferably 0 to 5, more preferably 0 to 3, and even more preferably 1 or 2. When n is an integer of 2 or more, Rz is 2 or more. ０１may be the same or different. In the formula (a1-3), n≦q×2+4. For example, when q is 1 and the naphthalene structure is formed, all six hydrogen atoms of the naphthalene are the same as those of the Rz ０１ In addition, in the naphthalene, Ya ００１ , -Ya ０１ -C(=O)-O-Rax ０１ group, and the Rz ０１ The substitution position of is not particularly limited.

[0106] Specific examples of the structural unit (a1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116] In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group. Rz represents a hydrogen atom, an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxy group, or an alkoxy group.

[0117]

[0118]

[0119]

[0120]

[0121]

[0122] The structural unit (a1) contained in the component (A1) may be of one type, or may be of two or more types. As the structural unit (a1), a structural unit represented by the above formula (a1-1) or a structural unit represented by the above formula (a1-3) is more preferred, as these tend to further improve the properties (sensitivity, shape, etc.) in lithography using electron beams or EUV. Among these, an acid-dissociable group (Ra １ , Rax ０１ ) are preferably acid-dissociable groups represented by the above general formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4), respectively, and among these, it is particularly preferable to select those which are cyclic groups.

[0123] Alternatively, the structural unit (a1) may include a structural unit represented by the following general formula (a1-1-1) or (a1-3-1).

[0124] [In the formula, Ra １ " is an acid-dissociable group represented by general formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4). * represents a bond.]

[0125] In the formula (a1-1-1), R, Va １ and n ａ１ represents R, Va in the formula (a1-1). １ and n ａ１ is the same as:

[0126] In the formula (a1-3-1), R, Ya 00１ , Ya 0１ , Rz ０１ , q, and n represent R, Ya in the formula (a1-3). 00１ , Ya 0１ , Rz ０１ , q, and n.

[0127] The acid-dissociable group represented by general formula (a1-r2-1), (a1-r2-3), (a1-r2-4), or (a1-r-4) is as described above. Among these, it is preferable to select an acid-dissociable group that is a cyclic group, as this is suitable for use with EB or EUV and can enhance reactivity.

[0128] The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol %, more preferably 10 to 75 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 70 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a1) is at least the lower limit of the above-mentioned preferred range, lithography properties such as sensitivity, resolution, and CDU improvement are improved. On the other hand, by ensuring that the proportion is at most the upper limit of the above-mentioned preferred range, a balance with other structural units can be achieved, resulting in various favorable lithography properties.

[0129] <<Other Structural Units>> The component (A1) may include, in addition to the above-described structural unit (a1), other structural units as necessary. Examples of such other structural units include the structural unit (a10) represented by general formula (a10-1) described below, a structural unit (a2) containing a lactone-containing cyclic group, a structural unit (a5) that generates acid upon exposure, a structural unit (a6) that has acid diffusion-controlling properties, and a structural unit (a8) derived from a compound represented by general formula (a8-1) described below.

[0130] Structural Unit (a10): The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0131] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ｘ１ is a single bond or a divalent linking group. ｘ１ is an aromatic hydrocarbon group which may have a substituent. ａｘ１ is an integer of 1 or greater.

[0132] In the formula (a10-1), R is the same as R in the 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 from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferred.

[0133] In the formula (a10-1), Ya ｘ１ is a single bond or a divalent linking group. ｘ１ The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0134] Divalent hydrocarbon group which may have a substituent: The divalent hydrocarbon group which may have a substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0135] Aliphatic hydrocarbon group: An aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups that contain a ring in their structure.

[0136] ...Straight-chain or branched-chain aliphatic hydrocarbon group The straight-chain aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５The branched chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched chain aliphatic hydrocarbon group, a branched chain alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0137] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, such as a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, or a carbonyl group.

[0138] ...Aliphatic hydrocarbon groups containing a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) that may contain a heteroatom-containing substituent in the ring structure, groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon groups include those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ]decane, tetracyclododecane, and the like.

[0139] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and even more preferably a methoxy group or an ethoxy group. The halogen atom as the substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. The cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure substituted with a substituent containing a heteroatom. The substituent containing a hetero atom includes —O—, —C(═O)—O—, —S—, and —S(═O) ２ -, -S(=O) ２ —O— is preferred.

[0140] Aromatic Hydrocarbon Group The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene groups or heteroarylene groups); groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., groups in which one further hydrogen atom has been removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0141] In the aromatic hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0142] Divalent linking group containing a hetero atom: Examples of the divalent linking group containing a hetero atom include -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, and -S(=O). ２ -, -S(=O) ２ -O-, 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 -, wherein Y ２１ and Y ２２are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer of 1 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. In the 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 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same as those described above. ２１ As Y, 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 an ethylene group is particularly preferred. ２２ is preferably 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. ２１ -C(=O)-O] ｍ” -Y ２２ In the group represented by -, m" is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. That is, the group represented by the formula -[Y ２１ -C(=O)-O] ｍ”-Y ２２ The group represented by - includes the group represented by the formula -Y ２１ -C(=O)-O-Y ２２ Among them, groups represented by the formula -(CH ２ ) ａ’ -C(=O)-O-(CH ２ ) ｂ’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0143] Ya ｘ１ is preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond or an ester bond [-C(=O)-O-, -O-C(=O)-].

[0144] In the formula (a10-1), Wa ｘ１ is an aromatic hydrocarbon group which may have a substituent. ｘ１ The aromatic hydrocarbon group in the formula (n) is an aromatic ring which may have a substituent. ａｘ１ Examples of the aromatic ring include a group in which 4n+1) hydrogen atoms have been removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings. Wa ｘ１The aromatic hydrocarbon group in (n) is selected from aromatic compounds containing an aromatic ring which may have two or more substituents (for example, biphenyl, fluorene, etc.). ａｘ１ Also included are groups in which one or more hydrogen atoms have been removed. ｘ１ Examples of the aryl group include benzene, naphthalene, anthracene, and biphenyl (n ａｘ１ A group in which (n +1) hydrogen atoms have been removed is preferred, and a group in which (n +1) hydrogen atoms have been removed from benzene or naphthalene is preferred. ａｘ１ A group in which (n +1) hydrogen atoms have been removed from benzene is more preferred, ａｘ１ A group in which 1) hydrogen atoms have been removed is more preferred.

[0145] Wa ｘ１ The aromatic hydrocarbon group in may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent include Ya ｘ１ Examples of the substituent include the same as those exemplified as the substituent of the cyclic aliphatic hydrocarbon group in Wa. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. ｘ１ The aromatic hydrocarbon group in the formula (I) preferably does not have a substituent.

[0146] In the formula (a10-1), n ａｘ１ is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, even more preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0147] Specific examples of the structural unit (a10) represented by the formula (a10-1) are shown below. α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0148]

[0149]

[0150]

[0151] The structural unit (a10) contained in the component (A1) may be one type, or two or more types. The component (A1) may or may not contain the structural unit (a10), but preferably contains the structural unit (a10). When the component (A1) contains the structural unit (a10), the proportion of the structural unit (a10) in the 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 (100 mol%) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a10) is at or above the lower limit, sensitivity is likely to be further improved. On the other hand, by ensuring that the proportion is at or below the upper limit, it is easier to achieve a balance with other structural units.

[0152] Structural unit (a2): The component (A1) may or may not have a structural unit (a2) (excluding those corresponding to the structural unit (a1)) that contains a lactone-containing cyclic group. When the component (A1) is used to form a resist film, the lactone-containing cyclic group of the structural unit (a2) is effective in improving the adhesion of the resist film to the substrate. Furthermore, the presence of the structural unit (a2) provides effects such as appropriate adjustment of the acid diffusion length, improved adhesion of the resist film to the substrate, and appropriate adjustment of solubility during development, resulting in improved lithography properties.

[0153] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) that contains -O-C(=O)- within its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, and when there is also another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. There are no particular restrictions on the lactone-containing cyclic group in the structural unit (a2), and any group can be used. Specific examples include groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0154] [In the formula, Ra' ２１are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group, or a cyano group; R″ is a hydrogen atom, an alkyl group, 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; n′ is an integer of 0 to 2, and m′ is 0 or 1. * represents a bond (the same applies hereinafter).

[0155] In the general formulas (a2-r-1) to (a2-r-7), Ra' ２１ The alkyl group in Ra' is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Of these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. Ra' ２１ The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, ２１ Examples of the alkyl groups include those mentioned as examples of the alkyl group in the above formula and an oxygen atom (—O—). ２１ The halogen atom in Ra' is preferably a fluorine atom. ２１ As the halogenated alkyl group in the above, Ra' ２１ Examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0156] Ra' ２１In -COOR" and -OC(=O)R" in the formula (I), R" is either a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group for R" may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R" is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably has 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably has 4 to 12 carbon atoms, and most preferably has 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, tricycloalkane, or tetracycloalkane. More specifically, groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; ２，６ ] decane, tetracyclododecane, and other polycycloalkanes in which one or more hydrogen atoms have been removed. Examples of the lactone-containing cyclic group in R" include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7). Ra' ２１ The hydroxyalkyl group in the formula (Ra') preferably has 1 to 6 carbon atoms. ２１ and a group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0157] Ra' ２１ Among the above, each of the groups is preferably independently a hydrogen atom or a cyano group.

[0158] In the general formulae (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms for A" is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between carbon atoms of the alkylene group, such as -O-CH ２ -, -CH ２ -O-CH ２ -, -S-CH ２ -, -CH ２ -S-CH ２ A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0159] Specific examples of the groups represented by general formulae (a2-r-1) to (a2-r-7) are listed below.

[0160]

[0161]

[0162] Of the structural units (a2), structural units derived from acrylate esters in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent are preferred. Such structural units (a2) are preferably structural units represented by the following general formula (a2-1):

[0163] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ２１ represents a single bond or a divalent linking group. ２１ represents -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, and R' represents a hydrogen atom or a methyl group. ２１ When is -O-, Ya ２１ does not become -CO-. ２１ is a lactone-containing cyclic group.

[0164] In the formula (a2-1), R is the same as defined 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 from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferred.

[0165] In the formula (a2-1), Ya ２１ The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. ２１ As the divalent linking group in the general formula (a10-1), ｘ１ Examples of the divalent linking group include the same as the divalent linking group in the above formula.

[0166] Ya ２１ is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof.

[0167] In the formula (a2-1), Ya ２１ is a single bond, and La ２１ is preferably —COO— or —OCO—.

[0168] In the formula (a2-1), Ra ２１ is a lactone-containing cyclic group. ２１ Suitable examples of the lactone-containing cyclic group in the formula (a2-r-1) include the groups represented by the general formulae (a2-r-1) to (a2-r-7) described above.

[0169] The structural unit (a2) contained in the component (A1) may be of one type, or may contain two or more types. The component (A1) may or may not contain the structural unit (a2). When the component (A1) contains the structural unit (a2), the proportion of the structural 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 structural units constituting the component (A1). When the proportion of the structural unit (a2) is at least the preferred lower limit, the effects achieved by including the structural unit (a2) can be fully obtained due to the aforementioned effects. When the proportion is at or below the upper limit, a balance with the other structural units can be achieved, resulting in various favorable lithography properties.

[0170] Structural Unit (a5): The component (A1) may or may not include a structural unit (a5) that generates acid upon exposure. Known structural units can be used as the structural unit (a5). By including the structural unit (a5), the acid generated upon exposure tends to be more uniformly distributed within the resist film. Examples of the structural unit (a5) include structural units containing a structure as described below for the component (B). Examples include structural units containing a structure represented by any of the below-described general formulas (b-1) to (b-3). Suitable examples of the structural unit (a5) include structural units represented by the following general formula (a5-1):

[0171] [In the formula, R ｍ is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. ５０ is a divalent linking group or a single bond. ５０ represents a divalent hydrocarbon group which may have a substituent. ａ５ is an integer from 0 to 2. ５１ is a divalent linking group. ５ is a divalent linking group which may have a heteroatom, or a single bond. ５１ and Ra ５２ are each independently a hydrogen atom, a fluorine atom or a fluorinated alkyl group, n5 is an integer of 1 to 4, m is an integer of 1 or more, and M'ｍ＋ is an m-valent onium cation.

[0172] {Anion moiety} In the formula (a5-1), R ｍ is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group 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, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Examples of halogen atoms include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. As the halogen atom in the halogenated alkyl group, a fluorine atom is particularly preferred. R ｍ As the alkyl group, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferred.

[0173] In the formula (a5-1), La ５０ is a divalent linking group or a single bond. ５０ The divalent linking group in the formula (I) is not particularly limited, but a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom are preferred. ｘ１ The divalent linking group is the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom exemplified in the above. ５０ is preferably 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. ５is more preferably an ester bond [—C(═O)—O—, —O—C(═O)—] or a single bond, and further preferably an ester bond [—C(═O)—O—, —O—C(═O)—].

[0174] In the formula (a5-1), Ra ５０ is a divalent hydrocarbon group which may have a substituent. ５０ The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0175] .Ra ５０ The aliphatic hydrocarbon group in the above formula (1) means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

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

[0177] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, such as a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, or a carbonyl group.

[0178] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) that may contain a heteroatom-containing substituent in the ring structure, groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon groups include those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ]decane, tetracyclododecane, and the like.

[0179] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. The cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure substituted with a substituent containing a heteroatom. The substituent containing a hetero atom includes —O—, —C(═O)—O—, —S—, and —S(═O) ２ -, -S(=O) ２ —O— is preferred.

[0180] .Ra ５０The aromatic hydrocarbon group in the above formula (1) is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene groups or heteroarylene groups); groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., groups in which one further hydrogen atom has been removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0181] In the aromatic hydrocarbon group, a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent that substitutes a hydrogen atom contained in the cyclic aliphatic hydrocarbon group.

[0182] In the formula (a5-1), n ａ５ is an integer of 0 to 2. Among the above, Ra ５０ is preferably an aliphatic hydrocarbon group containing a ring in its structure, more preferably a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure, and even more preferably an alicyclic hydrocarbon group which is a polycyclic group or a monocyclic group and may have a substituent. ５０ is preferably an aromatic hydrocarbon group.

[0183] n ａ５ If is 2, then two Ra ５０ may all be alicyclic hydrocarbon groups which may have a substituent, may all be aromatic hydrocarbon groups, or may be a combination of alicyclic hydrocarbon groups which may have a substituent and aromatic hydrocarbon groups.

[0184] In the formula (a5-1), La ５１ is a divalent linking group. ５１Examples of the divalent linking group in the formula (I) include non-hydrocarbon oxygen atom-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-O-C(=O)-O-); and combinations of such non-hydrocarbon oxygen atom-containing linking groups with alkylene groups. These combinations may also be further combined with a sulfonyl group (-SO ２ Examples of such a divalent linking group include the linking groups represented by the following general formulae (L-al-1) to (L-al-8). In the following general formulae (L-al-1) to (L-al-8), Ra in the above formula (a5-1) may be ５０ and V' in the following general formulae (L-al-1) to (L-al-8) １０１ is.

[0185] [In the formula, V' １０１ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' １０２ is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0186] 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.

[0187] V' １０１ and V' １０２ The alkylene group in V' may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group. １０１ and V' １０２ Specific examples of the alkylene group in ２ -]; -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH 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 -]; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, etc.; a trimethylene group (n-propylene group) [—CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ an alkyltrimethylene group such as -; a tetramethylene group [-CH ２ CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ -, etc.; an alkyltetramethylene group such as a pentamethylene group [—CH ２ CH ２ CH ２ CH ２ CH ２ -]. Also, V' １０１ or V' １０２ In the formula (a1-r-1), some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by Ra' in the formula (a1-r-1).３ A divalent group obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group) of the above formula (I) is preferred, and a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferred.

[0188] La ５１ As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, the linking groups represented by the above formulae (L-al-1) to (L-al-5) and (L-al-8) are more preferable, and the linking group represented by (L-al-3) or (L-al-8) is even more preferable.

[0189] In the formula (a5-1), Ya ５ represents a divalent linking group which may have a heteroatom, or a single bond. ５ The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. ５ The divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom in ｘ１ The divalent linking group is the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom exemplified in the above. ５ is preferably a linear or branched alkylene group or a single bond, and more preferably a single bond.

[0190] In the formula (a5-1), Ra ５１ and Ra ５２ are each independently a hydrogen atom, a fluorine atom or a fluorinated alkyl group. ５１ and Ra ５２ In the formula (a5-1), the fluorinated alkyl group is preferably a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms, and more preferably a trifluoromethyl group. ３ － Ra bonded to the carbon atom adjacent to ５１ and Ra ５２From the viewpoint of acid strength, it is preferable that at least one of the groups is a fluorine atom.

[0191] In the formula (a5-1), n5 represents an integer of 1 to 4, and is preferably 1, 2, or 3.

[0192] {Cation moiety} In the formula (a5-1), M' ｍ＋ represents an m-valent onium cation. ｍ＋ is preferably a sulfonium cation or an iodonium cation, and m is an integer of 1 or more.

[0193] Preferred cationic moieties ((M' ｍ＋ ) １／ｍ ) includes organic cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[0194] [In the formula, R ２０１ ~R ２０７ R each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ２０１ ~R ２０３ , R ２０６ ~R ２０７ may be bonded to each other to form a ring together with the sulfur atom in the formula. ２０８ ~R ２０９ R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ２１０ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an —SO ２ -containing cyclic group. ２０１ represents —C(═O)— or —C(═O)—O—.]

[0195] In the above general formulas (ca-1) to (ca-3), R ２０１ ~R ２０７ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２０１ ~R ２０７The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２０１ ~R ２０７ , and R ２１０ Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulae (ca-r-1) to (ca-r-7):

[0196] [In the formula, R' ２０１ are each independently a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0197] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group which does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0198] R' ２０１ The aromatic hydrocarbon group in R' is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. ２０１ Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in R' include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. ２０１Specific examples of the aromatic hydrocarbon group in the formula (I) include groups in which one hydrogen atom has been removed from the aromatic ring (aryl groups: for example, phenyl group, naphthyl group, etc.), and groups in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0199] R' ２０１ Examples of the cyclic aliphatic hydrocarbon group in the formula (I) include aliphatic hydrocarbon groups containing a ring within their structure. Examples of aliphatic hydrocarbon groups containing a ring within their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed within a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be either a polycyclic group or a monocyclic group. Preferred monocyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a monocycloalkane. Preferred monocycloalkanes have 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. Preferred polycyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkanes include adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ] Polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as decane and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton, are more preferred.

[0200] Among them, R' ２０１The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0201] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, —CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２-, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0202] Also, R' ２０１ The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specifically, lactone-containing cyclic groups represented by the above general formulae (a2-r-1) to (a2-r-7), —SO ２ -containing cyclic groups, and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16).

[0203]

[0204] R' ２０１Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. The halogen atom as a substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, in which some or all of the hydrogen atoms have been substituted with the halogen atoms. The carbonyl group as a substituent is a methylene group (-CH ２ -) is a group that substitutes

[0205] A chain alkyl group which may have a substituent: R' ２０１ The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0206] A chain alkenyl group which may have a substituent: R' ２０１The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of linear alkenyl groups include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of branched alkenyl groups include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the above chain alkenyl groups, linear alkenyl groups are preferred, with a vinyl group and a propenyl group being more preferred, and a vinyl group being particularly preferred.

[0207] R' ２０１ Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, the above-mentioned R' ２０１ Examples of the cyclic groups include the cyclic groups shown in the formula:

[0208] R' ２０１ In addition to the above-mentioned optionally substituted cyclic groups, optionally substituted chain alkyl groups, and optionally substituted chain alkenyl groups, examples of the optionally substituted cyclic groups or optionally substituted chain alkyl groups include those similar to the acid-dissociable group represented by formula (a1-r-2) above.

[0209] Among them, R' ２０１ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane; a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7) above; -SO represented by each of the general formulae (b5-r-1) to (b5-r-4) described below; ２ -containing cyclic groups are preferred.

[0210] In the above general formulas (ca-1) to (ca-3), R ２０１ ~R ２０３ , R ２０６ ~R ２０７When they are bonded to each other to form a ring together with the sulfur atom in the formula, they are not substituted with heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, or with carbonyl groups, -SO-, -SO ２ -, -SO ３ -, -COO-, -CONH- or -N(R Ｎ )-(the R Ｎ is an alkyl group having 1 to 5 carbon atoms.) As for the ring formed, one ring containing a sulfur atom in its ring skeleton in the formula is preferably a 3- to 10-membered ring including the sulfur atom, and particularly preferably a 5- to 7-membered ring. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0211] R ２０８ ~R ２０９ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when they are alkyl groups, they may be bonded to each other to form a ring.

[0212] R ２１０ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an —SO ２ -containing cyclic group. ２１０ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２１０ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２１０ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２１０ In the -SO ２ The -containing cyclic group is not particularly limited and any group can be used. Specific examples include groups represented by the following general formulae (b5-r-1) to (b5-r-4), and "-SO ２-containing polycyclic group" is preferred, and a group represented by general formula (b5-r-1) is more preferred.

[0213] [In the formula, Rb' ５１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group, or a cyano group; R″ is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or —SO ２ -containing cyclic group; 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; n' is an integer of 0 to 2; * represents a bond.

[0214] In the general formulae (b5-r-1) and (b5-r-2), B" represents 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.

[0215] In the general formulae (b5-r-1) to (b5-r-4), Rb' ５１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group, or a cyano group, and among these, are preferably each independently a hydrogen atom or a cyano group.

[0216] Specific examples of the groups represented by general formulae (b5-r-1) to (b5-r-4) are listed below, where "Ac" represents an acetyl group.

[0217]

[0218]

[0219]

[0220] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas.

[0221]

[0222]

[0223] [In the formula, g1, g2, and g3 represent the number of repeating units, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 1 to 20.]

[0224]

[0225]

[0226] [In the formula, R” ２０１ is a hydrogen atom or a substituent, and the substituent is the same as R ２０１ ~R ２０７ , and R ２１０ The substituents are the same as those exemplified as the substituents that may be possessed by

[0227]

[0228] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0229] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0230]

[0231] The cation moiety ((M' ｍ＋ ) １／ｍAs the cation represented by the formula (ca-1), a sulfonium cation is preferable, the cations represented by the formulas (ca-1) to (ca-3) are more preferable, the cation represented by the formula (ca-1) is even more preferable, and the cations represented by the formulas (ca-1-1) to (ca-1-84) are particularly preferable. In particular, from the viewpoint of increasing sensitivity, the preferred cation represented by the formula (ca-1) is preferably one having an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, or a sulfonyl group as a substituent, and for example, a cation selected from the group consisting of the cations represented by the formulas (ca-1-44), (ca-1-71) to (ca-1-84) are particularly preferable.

[0232] Specific preferred examples of the structural unit (a5) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group. ｍ＋ represents m and M' in the general formula (a5-1). ｍ＋ is the same as:

[0233]

[0234]

[0235]

[0236] The structural unit (a5) contained in the component (A1) may be of one type, or may be of two or more types. When the component (A1) contains the structural unit (a5), the proportion of the structural unit (a5) in the component (A1) is preferably 5 to 25 mol %, more preferably 10 to 20 mol %, and even more preferably 15 to 20 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). When the proportion of the structural unit (a5) is at least the lower limit of the above-mentioned preferred range, it becomes easier to achieve even higher sensitivity and improved resolution. On the other hand, when the proportion is at most the upper limit of the above-mentioned preferred range, it becomes easier to achieve a balance with other structural units.

[0237] Structural unit (a6): The structural unit (a6) is a structural unit that has acid diffusion controllability. The component (A1) may or may not have the structural unit (a6). Known structural units can be used as the structural unit (a6). Examples of the structural unit (a6) include structural units containing the structures described for the components (D1) and (D2) described below. Examples include structural units containing a structure represented by any of the general formulas (d1-1) to (d1-3) described below.

[0238] The structural unit (a6) contained in the component (A1) may be of one type, or may be of two or more types. When the component (A1) contains the structural unit (a6), the proportion of the structural unit (a6) in the 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 (100 mol %) of all structural units constituting the component (A1). When the proportion of the structural unit (a6) is at least the lower limit of the above-mentioned preferred range, it becomes easier to achieve even higher sensitivity. On the other hand, when the proportion is at most the upper limit of the above-mentioned preferred range, it becomes easier to achieve a balance with the other structural units.

[0239] Structural Unit (a8): The structural unit (a8) is a structural unit derived from a compound represented by the following general formula (a8-1): The component (A1) may or may not include the structural unit (a8).

[0240] [In the formula, W ２ is a polymerizable group-containing group. ｘ２ is a single bond or (n ａｘ２ +1)valent linking group. ｘ２ and W ２ may form a condensed ring. １ is a fluorinated alkyl group having 1 to 12 carbon atoms. ２ is a hydrogen atom or an organic group having 1 to 12 carbon atoms which may have a fluorine atom. ２ and Ya ｘ２ may be bonded to each other to form a ring structure. ａｘ２ is an integer from 1 to 3.

[0241] W ２The "polymerizable group" in the polymerizable group-containing group is a group that enables a compound having a polymerizable group to be polymerized by radical polymerization or the like, and refers to a group that contains a multiple bond between carbon atoms, such as an ethylenic double bond.

[0242] The polymerizable group-containing group may be a group composed of only a polymerizable group, or may be a group composed of a polymerizable group and a group other than the polymerizable group. Examples of the group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Examples of the polymerizable group-containing group include a group represented by the chemical formula: C(R Ｘ１１ ) (R Ｘ１２ ) = C(R Ｘ１３ ) -Ya ｘ０ In this chemical formula, R Ｘ１１ , R Ｘ１２ and R Ｘ１３ are each 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 is a single bond or a divalent linking group.

[0243] Ya ｘ２ and W ２ The fused ring formed by ２ The polymerizable group at the site and Ya ｘ２ and a fused ring formed by W ２ Other groups than the polymerizable group at the Ya ｘ２ and a fused ring formed by ｘ２ and W ２ The fused ring formed by these may have a substituent.

[0244] Specific examples of the structural unit (a8) are shown below. α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0245]

[0246] Among the above examples, the structural unit (a8) is preferably at least one selected from the group consisting of structural units represented by 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 structural units represented by chemical formulas (a8-1-01) to (a8-1-04), and (a8-1-09).

[0247] The structural unit (a8) contained in the component (A1) may be of one type, or may contain two or more types. The component (A1) may or may not contain the structural unit (a8). The proportion of the structural unit (a8) in the component (A1) is preferably 0 to 50 mol %, and more preferably 0 to 30 mol %, relative to the total (100 mol %) of all structural units constituting the component (A1).

[0248] The resist composition may contain one type of component (A1), or two or more types of components may be used in combination.

[0249] Examples of the component (A1) include a polymeric compound having the structural unit (a1) and the structural unit (a10), and a polymeric compound having the structural unit (a1), the structural unit (a10), and the structural unit (a2). Preferred examples of the component (A1) include a polymeric compound consisting of the structural unit (a1) and the structural unit (a10), and a polymeric compound consisting of the structural unit (a1), the structural unit (a10), and the structural unit (a2), with a polymeric compound consisting of the structural unit (a1) and the structural unit (a10) being more preferred.

[0250] In a polymeric compound comprising the structural unit (a1) and the structural unit (a10), the proportion of the structural unit (a1) relative to the total (100 mol%) of all structural units constituting the polymeric compound is preferably 10 to 75 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 70 mol%. The proportion of the structural unit (a10) in the polymeric compound relative to the total (100 mol%) of all structural units constituting the polymeric compound is preferably 25 to 90 mol%, more preferably 30 to 70 mol%, and even more preferably 30 to 60 mol%.

[0251] In a polymeric compound composed of the structural unit (a1), the structural unit (a10), and the structural unit (a2), the proportion of the structural unit (a1) is preferably 10 to 85 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 70 mol%, relative to the total (100 mol%) of all structural units constituting the polymeric compound. The proportion of the structural unit (a10) in the polymeric compound is preferably 10 to 85 mol%, more preferably 30 to 70 mol%, and even more preferably 30 to 60 mol%, relative to the total (100 mol%) of all structural units constituting the polymeric compound. The proportion of the structural unit (a2) in the polymeric compound is preferably 5 to 80 mol%, more preferably 10 to 60 mol%, and even more preferably 10 to 40 mol%, relative to the total (100 mol%) of all structural units constituting the polymeric compound.

[0252] The component (A1) can be produced by dissolving the monomers that derive each structural unit in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the solution and polymerizing. Alternatively, the component (A1) can be produced by dissolving a monomer that derives the structural unit (a1) and a monomer that derives any structural unit (e.g., structural unit (a10), structural unit (a5), etc.) in a polymerization solvent, adding a radical polymerization initiator such as those described above to polymerize, and then carrying out a deprotection reaction. During the polymerization, for example, HS-CH ２ -CH ２ -CH ２ -C(CF ３ ) ２ By using a chain transfer agent such as —OH in combination, it is possible to obtain a chain with —C(CF ３ ) ２ A copolymer having a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group have been substituted with fluorine atoms is thus introduced, and is effective in reducing development defects and LER (line edge roughness: non-uniform irregularities on the line sidewalls).

[0253] The weight-average molecular weight (Mw) of component (A1) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and even more preferably 5,000 to 30,000. When the Mw of component (A1) is equal to or less than the preferred upper limit of this range, the component has sufficient solubility in a resist solvent for use as a resist, while when the Mw is equal to or greater than the preferred lower limit of this range, the component exhibits good dry etching resistance and resist pattern cross-sectional shape. The dispersity (Mw / Mn) of component (A1) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Here, Mn represents the number-average molecular weight.

[0254] Regarding the component (A2): The resist composition of this embodiment may also use, as the component (A), a base component (A2) (hereafter referred to as "component (A2)") that does not fall under the category of the component (A1) and whose solubility in a developer changes under the action of acid. There are no particular limitations on the component (A2), and it may be arbitrarily selected from the many base components conventionally known for use in chemically amplified resist compositions. The component (A2) may be a polymeric compound or a low molecular weight compound, and may be used either alone or in combination of two or more types.

[0255] The proportion of the component (A1) within the component (A), relative to the total weight of the component (A), is preferably 25 mass% or more, more preferably 50 mass% or more, and even more preferably 75 mass% or more, and may even be 100 mass%. When this proportion is 25 mass% or more, a resist pattern that is excellent in various lithography properties, such as high sensitivity, resolution, and improved CDU, is more likely to be formed.

[0256] The amount of the component (A) in the resist composition of this embodiment may be adjusted depending on factors such as the thickness of the resist film to be formed.

[0257] <Compound (C)> Compound (C) is a compound represented by the following general formula (c0), and has one or more thiophene rings and one or more benzene rings having one or more electron-withdrawing groups as substituents at the ortho- or meta-positions. By including compound (C), the resist composition of this embodiment exhibits high sensitivity and suppresses the occurrence of defects during resist pattern formation.

[0258] [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent. － represents a counter anion.

[0259] {Cation moiety of compound (C)} In the formula (c0), X ０１ is an electron-withdrawing group, and is preferably a halogen atom, a halogenated alkyl group, a sulfonyl group, a nitro group, a cyano group, a trifluoromethoxy group, or a carbonyl group, and more preferably a trifluoromethyl group, a fluorine atom, or an iodine atom. In the formula (c0), j is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2. ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same as or different from each other.

[0260] The R ０１is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. Examples of the aryl group include an unsubstituted aryl group having 6 to 20 carbon atoms, and an aryl group having 4 to 20 carbon atoms in which some of the carbon atoms constituting the aryl group are substituted with heteroatoms, and a phenyl group, a naphthyl group, or a thiophene group is preferred. The alkyl group is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. The alkenyl group preferably has 2 to 10 carbon atoms. ０１ The aryl group, alkyl group, or alkenyl group in the formula (c-r-1) may or may not have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the above general formulae (c-r-1) to (c-r-7).

[0261] The benzene ring in the formula is X ０１ The substituent may or may not have a substituent other than the above. ０１ The thiophene ring in the formula may or may not have a substituent. Examples of the substituent include the substituents in the above-mentioned R ０１ The substituents are the same as those in the above.

[0262] The compound (C) is preferably a compound (C') represented by the following general formula (c0').

[0263] [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. The benzene ring in the formula ０１ The thiophene ring in the formula may have a substituent other than R. ｒ is a benzene ring or a thiophene ring. ｒ is a benzene ring, R ０２is an electron-withdrawing group; k is an integer from 1 to 5; R ０２ is bonded at least to the ortho or meta position. ｒ is a benzene ring and k is an integer of 2 or more, ０２ may be the same or different. ｒ The benzene ring of R ０２ may have a substituent other than R ｒ is a thiophene ring, R ０２ is a substituent, and k is an integer of 0 to 3. ｒ is a thiophene ring and k is an integer of 2 or more, ０２ may be the same or different. － represents a counter anion.

[0264] In the formula (c0′), X ０１ , j is X in the formula (c0). ０１ , j. In the formula (c0′), X ０１ is preferably a halogen atom, a halogenated alkyl group, a sulfonyl group, a nitro group, a cyano group, a trifluoromethoxy group, or a carbonyl group, and more preferably a trifluoromethyl group, a fluorine atom, or an iodine atom. In formula (c0'), j is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0265] In the formula (c0′), R ｒ is a benzene ring or a thiophene ring, and a benzene ring is preferred. ｒ is a benzene ring, ０２ is an electron-withdrawing group, and X in the formula (c0) ０１ k is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2. R ０２ is bonded at least to the ortho or meta position. ｒ is a benzene ring and k is an integer of 2 or more, ０２ may be the same or different. ｒ The benzene ring of R ０２ The substituent may be, for example, any of the substituents R０１ The substituents in R ｒ is a thiophene ring, R ０２ is a substituent, and k is an integer of 0 to 3, preferably an integer of 0 to 2, and more preferably 0 or 1. ｒ is a thiophene ring and k is an integer of 2 or more, ０２ may be the same or different. ０１ The substituents are the same as those in the above.

[0266] Specific examples of the cation moiety of the compound (C) are shown below.

[0267]

[0268]

[0269]

[0270]

[0271]

[0272]

[0273] {Anion portion of compound (C)} In the formulas (c0) and (c0′), Xc － represents a counter anion. － Examples of the counter anion in Xc include a sulfonate anion, a carboxylate anion, an imide anion, a methide anion, a carbonate anion, a borate anion, a halogen anion, a phosphate anion, an antimonate anion, and an arsenate anion. － The counter anion in is preferably an anion selected from the group consisting of anions represented by any of the below-mentioned general formulae (b-an-1) to (b-an-3) and the below-mentioned general formulae (d1-an-1) to (d1-an-3), and more preferably an anion selected from the group consisting of anions represented by any of the below-mentioned general formulae (b-an-1) and (d1-an-1).

[0274] In the resist composition of this embodiment, the compound (C) may be an acid generator component (B) that generates an acid upon exposure, or may be a base component (component (D)) that traps the acid generated upon exposure (i.e., controls the diffusion of the acid).

[0275] In the resist composition of this embodiment, compound (C) preferably contains, as component (B), a compound represented by the following general formula (b0) (hereafter referred to as “compound (b0)”).

[0276] [In the formula, M ｂ＋ is the cation moiety of the compound (C). － is one or more anions selected from the group consisting of anions represented by any one of the following general formulas (b-an-1), (b-an-2), and (b-an-3):

[0277] [In the formula, R １０１ and R １０４ ~R １０８ R are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. １０４ and R １０５ may be bonded to each other to form a ring structure. １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０１ is a divalent linking group containing an oxygen atom or a single bond. １０１ ~V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. １０１ and V １０１ cannot be a single bond at the same time. １０１ ~L １０２ are each independently a single bond or an oxygen atom. １０３ ~L １０５ each independently represents a single bond, —CO— or —SO ２ - is.]

[0278] In the above formula (b0), M ｂ＋ is the same as the cation moiety of the compound (C).

[0279] {Anion portion} Anion represented by general formula (b-an-1) In formula (b-an-1), R １０１ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0280] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group which does not have aromaticity. Furthermore, the aliphatic hydrocarbon group is preferably saturated.

[0281] R １０１ The aromatic hydrocarbon group in R is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. １０１ Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in R include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. １０１ Specific examples of the aromatic hydrocarbon group in include groups in which one hydrogen atom has been removed from the aromatic ring (aryl groups: for example, phenyl group, naphthyl group, etc.), and groups in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, etc.). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 or 2, and particularly preferably 1.

[0282] R １０１Examples of the cyclic aliphatic hydrocarbon group in the formula (I) include aliphatic hydrocarbon groups containing a ring within their structure. Examples of aliphatic hydrocarbon groups containing a ring within their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed within a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be either a polycyclic group or a monocyclic group. Preferred monocyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a monocycloalkane. Preferred monocycloalkanes have 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. Preferred polycyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkanes include adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ] Polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as decane and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton, are more preferred.

[0283] Among them, R １０１ The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0284] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ )２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ -] and the like. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0285] Also, R １０１ The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specifically, lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7), —SO 2 represented by the general formulae (b5-r-1) to (b5-r-4), ２ -containing cyclic groups, and other heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16), respectively.

[0286] R １０１ Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. The halogen atom as a substituent is preferably a fluorine atom, a bromine atom, or an iodine atom. Examples of the halogenated alkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the halogen atoms. The carbonyl group as a substituent is a methylene group (-CH) constituting a cyclic hydrocarbon group. ２ -) is a group that substitutes

[0287] R １０１The cyclic hydrocarbon group in may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a bridged ring polycyclic skeleton to which one or more aromatic rings are fused. Specific examples of the bridged ring polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. １０１ Specific examples of the fused cyclic group in formula (b-an-1) include groups represented by the following formulae (r-br-1) and (r-br-2). １０１ represents a bond bonded to

[0288]

[0289] R １０１ Examples of the substituent that the fused cyclic group in the formula (I) may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, etc. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused cyclic group can be selected from the group consisting of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused cyclic group described above in R １０１ Examples of the aromatic hydrocarbon group as a substituent of the fused cyclic group include a group in which one hydrogen atom has been removed from an aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-16). Examples of the alicyclic hydrocarbon group as a substituent of the fused cyclic group include a group in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0２，６ a group in which one hydrogen atom has been removed from a polycycloalkane such as decane or tetracyclododecane; a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7); a —SO 2 group represented by each of the general formulae (b5-r-1) to (b5-r-4), ２ -containing cyclic group: heterocyclic groups represented by the above formulae (r-hr-7) to (r-hr-16), respectively.

[0290] A chain alkyl group which may have a substituent: R １０１ The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0291] A chain alkenyl group which may have a substituent: R １０１ The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the above chain alkenyl groups, a linear alkenyl group is preferred, a vinyl group or a propenyl group is more preferred, and a vinyl group is particularly preferred.

[0292] R １０１Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the R １０１ Examples of the cyclic groups include the cyclic groups shown in the formula:

[0293] In formula (b-an-1), Y １０１ is a single bond or a divalent linking group containing an oxygen atom. １０１ is a divalent linking group containing an oxygen atom, １０１ may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of divalent linking groups containing oxygen atoms include linking groups represented by the above general formulas (L-al-1) to (L-al-8). In the above general formulas (L-al-1) to (L-al-8), R in the above formula (b-an-1) １０１ The group that bonds to V' in the above general formulae (L-al-1) to (L-al-8) is １０１ is.

[0294] In formula (b-an-1), V １０１ is a single bond, an alkylene group or a fluorinated alkylene group. １０１ is preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0295] In formula (b-an-1), R １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０２ is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0296] Specific examples of the anion moiety represented by the formula (b-an-1) include, for example, Y １０１ When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; １０１ When is a divalent linking group containing an oxygen atom, examples of the anion include anions represented by any one of the following formulae (an-1) to (an-3).

[0297] [In the formula, R” １０１ R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by each of the above chemical formulas (r-hr-1) to (r-hr-16), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a chain alkyl group which may have a substituent, or an aromatic cyclic group which may have a substituent. １０２ represents an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the formula (r-br-1) or (r-br-2) above, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1), (a2-r-3) to (a2-r-7) above, or —SO ２ -containing cyclic group. １０３ V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. １０１ is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; each v" is independently an integer of 0 to 3; each q" is independently an integer of 0 to 20; and n" is 0 or 1.

[0298] R” １０１ , R” １０２ and R” １０３ The aliphatic cyclic group which may have a substituent is represented by R １０１ The substituent is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in the formula (b-an-1). １０１ Examples of the substituents that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1).

[0299] R” １０１ and R” １０３ The aromatic cyclic group which may have a substituent in the formula (b-an-1) is R １０１The substituent is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in formula (b-an-1). １０１ Examples of the substituents that may substitute the aromatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0300] R” １０１ The chain alkyl group which may have a substituent in the formula (b-an-1) is R １０１ R" is preferably a group exemplified as a chain alkyl group in １０３ The chain alkenyl group which may have a substituent in the formula (b-an-1) is R １０１ Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0301] Anion represented by general formula (b-an-2) In formula (b-an-2), R １０４ , R １０５ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is represented by R １０１ However, R １０４ , R １０５ may be bonded to each other to form a ring. １０４ , R １０５ is preferably a chain alkyl group which may have a substituent, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms in the chain alkyl group is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. １０４ , R １０５ The number of carbon atoms in the chain alkyl group of R is preferably as small as possible within the above range of carbon atoms, for reasons such as good solubility in resist solvents. １０４ , R １０５In the chain alkyl group, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the improved transparency to high-energy light of 250 nm or less and electron beams, which is preferable. The proportion of fluorine atoms in the chain alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-an-2), V １０２ , V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-an-1). １０１ In formula (b-an-2), L １０１ , L １０２ are each independently a single bond or an oxygen atom.

[0302] Anion represented by general formula (b-an-3) In formula (b-an-3), R １０６ ~R １０８ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is represented by R １０１ In formula (b-an-3), L １０３ ~L １０５ each independently represents a single bond, —CO— or —SO ２ - is.

[0303] The cationic moiety in the compound (C) serving as the component (B) is preferably the cationic moiety in the formula (c0') above.

[0304] In the formula (c0′), X ０１ , j is X in the formula (c0). ０１ , j. In the formula (c0′), X ０１ is preferably a halogen atom, a halogenated alkyl group, a sulfonyl group, a nitro group, a cyano group, a trifluoromethoxy group, or a carbonyl group, and more preferably a trifluoromethyl group, a fluorine atom, or an iodine atom. In formula (c0'), j is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0305] In the formula (c0′), R ｒ is a benzene ring or a thiophene ring, and a benzene ring is preferred. ｒ is a benzene ring, ０２ is an electron-withdrawing group, and X in the formula (c0) ０１ k is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2. R ０２ is bonded at least to the ortho or meta position. ｒ is a benzene ring and k is an integer of 2 or more, ０２ may be the same or different. ｒ The benzene ring of R ０２ The substituent may be, for example, any of the substituents R ０１ The substituents in R ｒ is a thiophene ring, R ０２ is a substituent, and k is an integer of 0 to 3, preferably an integer of 0 to 2, and more preferably 0 or 1. ｒ is a thiophene ring and k is an integer of 2 or more, ０２ may be the same or different. ０１ The substituents are the same as those in the above.

[0306] As the anion moiety of compound (b0), among the above, anions represented by the above formula (b-an-1) or (b-an-2) are preferred, and an anion represented by the above formula (b-an-1) is more preferred.

[0307] Compound (b0) is preferably one selected from the group consisting of compounds represented by the following chemical formulas (C0-1) to (C0-11). Alternatively, among the above, compound (b0) is more preferably one selected from the group consisting of compounds represented by the following chemical formulas (C0-3) to (C0-9), as this more easily improves sensitivity, and even more preferably one selected from the group consisting of compounds represented by the following chemical formulas (C0-5), (C0-6), and (C0-8). Alternatively, among the above, compound (b0) is more preferably one selected from the group consisting of compounds represented by the following chemical formulas (C0-1) to (C0-6) and (C0-8) to (C0-11), as this more easily suppresses defect generation. Alternatively, from the viewpoint of achieving both high sensitivity and suppression of defect occurrence, compounds selected from the group consisting of compounds represented by the following chemical formulas (C0-3) to (C0-9) are more preferred, and compounds selected from the group consisting of compounds represented by the following chemical formulas (C0-5) or (C0-6), and (C0-8) are even more preferred.

[0308]

[0309]

[0310] In the resist composition of this embodiment, one type of compound (b0) may be used alone, or two or more types may be used in combination. In the resist composition of this embodiment, the content of compound (b0) relative to 100 parts by mass of component (A) is preferably 0.5 to 35 parts by mass, more preferably 1 to 30 parts by mass, even more preferably 3 to 25 parts by mass, and most preferably 5 to 20 parts by mass. When the content of compound (b0) is at least the lower limit of the above-mentioned preferred range, high sensitivity can be achieved during resist pattern formation, and the occurrence of defects can be more easily suppressed. On the other hand, when the content of compound (b0) is at most the upper limit of the above-mentioned preferred range, it is easier to maintain good sensitivity and solubility in a developer.

[0311] In the resist composition of this embodiment, compound (C) preferably includes, as component (D), a compound represented by general formula (d0) below (hereafter referred to as “compound (d0)”).

[0312] [In the formula, M ｄ＋ is the cation moiety of the compound (C). － is one or more anions selected from the group consisting of anions represented by any one of the following general formulas (d1-an-1), (d1-an-2) and (d1-an-3):

[0313] [In the formula, Rd １ ~Rd ４ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula, no fluorine atom is bonded to the carbon atom adjacent to the sulfur atom. １ represents a single bond or a divalent linking group.

[0314] In the above formula (d0), M ｄ＋ is the same as the cation moiety of the compound (C).

[0315] {Anion portion} Anion represented by general formula (d1-an-1) In formula (d1-an-1), Rd １ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of the R' ２０１ Among these, Rd １is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1) to (a2-r-7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the above formulas (L-al-1) to (L-al-5). Note that Rd １ In the case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group has a linking group represented by each of the above general formulae (L-al-1) to (L-al-7) as a substituent, in the above general formulae (L-al-1) to (L-al-7), Rd in formula (d1-an-1) １ The carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the formula (L-al-1) to (L-al-7) is bonded to V' １０１ Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and another ring structure). Suitable examples of the aliphatic cyclic group include adamantane, norbornane, isobornane, tricyclo[5.2.1.0], ２，６

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

[0316] When the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atom other than a fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0317] Preferred specific examples of the anion represented by general formula (d1-an-1) are shown below.

[0318]

[0319] Anion represented by general formula (d1-an-2) In formula (d1-an-2), Rd ２ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ However, Rd ２ In the formula, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not substituted with fluorine). This makes the anion of the component (d1-an-2) an appropriate weak acid anion, improving the quenching ability of the component (D). ２ The alkyl group is preferably a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent, and more preferably an aliphatic cyclic group which may have a substituent.

[0320] The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10. The aliphatic cyclic group includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0], ２，６ ] a group (which may have a substituent) in which one or more hydrogen atoms have been removed from decane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor is more preferred.

[0321] Rd ２The hydrocarbon group may have a substituent, and the substituent may be Rd １ Examples of the substituents include the same as those that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0322] Preferred specific examples of the anion represented by general formula (d1-an-2) are shown below.

[0323]

[0324] Anion represented by general formula (d1-an-3) In formula (d1-an-3), Rd ３ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ Among these, a fluorinated alkyl group is preferred, and the Rd １ The same fluorinated alkyl groups as those mentioned above are more preferred.

[0325] In formula (d1-an-3), Rd ４ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group, which may have a substituent, is preferable. ４ The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. ４ A part of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, etc. ４The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0326] Rd ４ The alkenyl group in R' ２０１ Examples include the same alkenyl groups as those in the above, and vinyl, propenyl (allyl), 1-methylpropenyl, and 2-methylpropenyl groups are preferred. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0327] Rd ４ The cyclic group in the formula (I) is the same as the R' ２０１ Examples thereof include cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclo[5.2.1.0], and the like. ２，６ ] An alicyclic group in which one or more hydrogen atoms have been removed from a cycloalkane such as decane or tetracyclododecane, or an aromatic group such as a phenyl group or naphthyl group is preferred. ４ When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in excellent lithography properties. ４ When is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency, and exhibits favorable sensitivity and lithography properties.

[0328] In formula (d1-an-3), Yd １ represents a single bond or a divalent linking group. １ The divalent linking group in is not particularly limited, but examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, and a divalent linking group containing a hetero atom. ２１Examples of the divalent linking group include the same divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom as those mentioned in the description of the divalent linking group in １ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and further preferably a methylene group or an ethylene group.

[0329] Preferred specific examples of the anion represented by general formula (d1-an-3) are shown below.

[0330]

[0331]

[0332] The compound (d0) is preferably the cation moiety in the formula (c0').

[0333] In the formula (c0′), X ０１ , j is X in the formula (c0). ０１ , j. In the formula (c0′), X ０１ is preferably a halogen atom, a halogenated alkyl group, a sulfonyl group, a nitro group, a cyano group, a trifluoromethoxy group, or a carbonyl group, and more preferably a trifluoromethyl group, a fluorine atom, or an iodine atom. In formula (c0'), j is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0334] In the formula (c0′), R ｒ is a benzene ring or a thiophene ring, and a benzene ring is preferred. ｒ is a benzene ring, ０２ is an electron-withdrawing group, and X in the formula (c0) ０１ k is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2. R ０２ is bonded at least to the ortho or meta position. ｒ is a benzene ring and k is an integer of 2 or more, ０２ may be the same or different. ｒThe benzene ring of R ０２ The substituent may be, for example, any of the substituents R ０１ The substituents in R ｒ is a thiophene ring, R ０２ is a substituent, and k is an integer of 0 to 3, preferably an integer of 0 to 2, and more preferably 0 or 1. ｒ is a thiophene ring and k is an integer of 2 or more, ０２ may be the same or different. ０１ The substituents are the same as those in the above.

[0335] As the anion moiety of the compound (d0), among the above, the anions represented by (d1-an-1) and (d1-an-2) are preferred, and the anion represented by (d1-an-1) is more preferred.

[0336] The compound (d0) is preferably a compound represented by the following chemical formula (C0-12).

[0337]

[0338] In the resist composition of this embodiment, one type of compound (d0) may be used alone, or two or more types may be used in combination. In the resist composition of this embodiment, the amount of compound (d0) relative to 100 parts by mass of component (A) is preferably 0.5 to 35 parts by mass, more preferably 1 to 30 parts by mass, even more preferably 3 to 25 parts by mass, and most preferably 5 to 20 parts by mass. When the amount of compound (d0) is at least the lower limit of the above-mentioned preferred range, high sensitivity can be achieved during resist pattern formation, and the occurrence of defects can be more easily suppressed. On the other hand, when the amount of compound (d0) is at most the upper limit of the above-mentioned preferred range, it is easy to maintain good sensitivity and solubility in a developer.

[0339] <Other Components> The resist composition of this embodiment may contain other components as necessary, in addition to the base component (A) and compound (C) described above.

[0340] <Acid Generator Component (B) (Excluding Compound (C))> The resist composition of this embodiment may contain an acid generator component (B) that generates an acid upon exposure (with the exception of compounds (C)). The component (B) is not particularly limited, and any of the components that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl- or bisarylsulfonyldiazomethanes and poly(bissulfonyl)diazomethanes, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. The component (B) may be contained in the form of a compound, or may be incorporated into the component (A1) as the structural unit (a5) described above, or may be in both of these forms.

[0341] Examples of the onium salt acid generator include compounds represented by the following general formulas (b-1) to (b-3).

[0342] [In the formula, R １０１ and R １０４ ~R １０８ R are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. １０４ and R １０５ may be bonded to each other to form a ring structure. １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０１ is a divalent linking group containing an oxygen atom or a single bond. １０１ ~V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. １０１ and V １０１ cannot be a single bond at the same time. １０１ ~L １０２ are each independently a single bond or an oxygen atom. １０３ ~L １０５each independently represents a single bond, —CO— or —SO ２ m is an integer of 1 or more, and M' ｍ＋ is an m-valent onium cation.

[0343] Examples of the anion moiety in the component (B) include the same anions as those represented by the above general formulas (b-an-1) to (b-an-3).

[0344] Of the above, the anion moiety of the component (B) is preferably the anion moiety of a compound represented by general formula (b-1), and more preferably the anion represented by formula (an-1).

[0345] {Cation Moiety in Component (B)} In the above formulae (b-1), (b-2), and (b-3), M' ｍ＋ represents an m-valent onium cation. Among these, sulfonium cation and iodonium cation are preferred. m is an integer of 1 or more.

[0346] The cation moiety of the component (B) is preferably a sulfonium cation, more preferably a cation represented by each of the formulas (ca-1) to (ca-3), still more preferably a cation represented by the formula (ca-1), and particularly preferably a cation represented by each of the formulas (ca-1-1) to (ca-1-84).

[0347] In the resist composition of this embodiment, the component (B) may be used singly, or two or more types may be used in combination. When the resist composition contains the component (B), the amount of the component (B) in the resist composition, relative to 100 parts by mass of the component (A), 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. By ensuring that the amount of the component (B) falls within the above-mentioned preferred range, a homogeneous solution is more likely to be obtained when the respective components of the resist composition are dissolved in an organic solvent, and the storage stability of the resist composition is favorable.

[0348] <<Base Component (D) (Excluding Compound (C))>> The resist composition of this embodiment may contain, in addition to the component (A), a base component (component (D)) that traps acid generated upon exposure (i.e., controls the diffusion of acid) (provided that this does not include compounds that fall under the category of compound (C)). The component (D) acts as a quencher (acid diffusion controller) that traps acid generated in the resist composition upon exposure. Examples of the component (D) include a photodegradable base (D1) (hereinafter referred to as “component (D1)”) that decomposes upon exposure and loses its ability to control acid diffusion, and a nitrogen-containing organic compound (D2) (hereinafter referred to as “component (D2)”) that does not fall under the category of component (D1). Among these, a photodegradable base (component (D1)) is preferred because it is likely to enhance all of the properties of high sensitivity, reduced roughness, and suppressed coating defects. The components (D1) and (D2) may be contained in the form of a compound, or in the form of being incorporated into the component (A1) as the structural unit (a6), or in both of these forms. The compounds exemplified below as the component (D1) may also be used as the acid generator component (component (B)) in combination with other compounds.

[0349] Regarding the component (D1): The component (D1) is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion controllability, and is preferably one or more compounds selected from the group consisting of compounds represented by the following general formulas (d1-1) to (d1-3) (hereinafter referred to as "components (d1-1) to (d1-3)"). The following components (d1-1) to (d1-3) decompose and lose their acid diffusion controllability (basicity) in the exposed areas of the resist film, and therefore do not function as quenchers, but function as quenchers in the unexposed areas of the resist film.

[0350] [In the formula, Rd １ ~Rd ４ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula, no fluorine atom is bonded to the carbon atom adjacent to the S atom. １is a single bond or a divalent linking group; m is an integer of 1 or more; M ｍ＋ are each independently an m-valent organic cation.

[0351] Examples of the anion moiety in the component (D1) include the same anions as those represented by the above general formulas (d1-an-1) to (d1-an-3).

[0352] {Cation moiety in component (d1-1)} In the above formula (d1-1), M ｍ＋ is an m-valent organic cation. ｍ＋ Suitable examples of the organic cation include the same as the cations represented by the general formulae (ca-1) to (ca-3), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the general formulae (ca-1-1) to (ca-1-84) being even more preferred. One type of component (d1-1) may be used alone, or two or more types may be used in combination.

[0353] {Cation moiety in component (d1-2)} In the above formula (d1-2), M ｍ＋ is an m-valent organic cation, and M in the formula (d1-1) ｍ＋ The component (d1-2) may be used alone or in combination of two or more.

[0354] {Cation moiety in component (d1-3)} In the above formula (d1-3), M ｍ＋ is an m-valent organic cation, and M in the formula (d1-1) ｍ＋ The component (d1-3) may be used alone or in combination of two or more.

[0355] The component (D1) may be any one of the above components (d1-1) to (d1-3), or a combination of two or more of them. When the resist composition contains the component (D1), the amount of the component (D1) within 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, relative to 100 parts by mass of the component (A).

[0356] The component (D1) preferably contains the component (d1-1). The content of the component (d1-1) in the entire component (D1) is preferably 50 mass% or more, more preferably 70 mass% or more, and even more preferably 90 mass% or more. The component (D1) may consist solely of the compound component (d1-1).

[0357] Production Method of Component (D1): The production methods of the components (d1-1) and (d1-2) described above are not particularly limited, and they can be produced by known methods. Furthermore, the production method of the component (d1-3) is also not particularly limited, and for example, it can be produced in a manner similar to the method described in US 2012-0149916 . The compound of component (D1) has been shown as an example of a base component (component (D)) that traps acid generated upon exposure, 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 a compound that generates an acid with a lower acidity than the acid generated by the compound of component (D1) upon exposure may be used as component (D). Furthermore, in the resist composition of this embodiment, the compound of component (D1) may be used as component (B), and the component (D2), described below, may be used as component (D).

[0358] Regarding the (D2) component: The (D) component may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the above-mentioned (D1) component. The (D2) component is not particularly limited as long as it acts as an acid diffusion controller and does not fall under the category of the (D1) component, and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are more preferred. The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of the aliphatic amine include ammonia NH ３Examples of the amine include amines in which at least one hydrogen atom is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), and cyclic amines. Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0359] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of aliphatic monocyclic amines include piperidine and piperazine. Specific examples of aliphatic polycyclic amines include those having 6 to 10 carbon atoms, such as 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0360] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, and the like, with triethanolamine triacetate being preferred.

[0361] Furthermore, the component (D2) may be an aromatic amine, such as 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole, or a derivative thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, or 2,6-di-tert-butylpyridine.

[0362] The component (D2) may be used singly, or in combination of two or more types. When the resist composition contains the component (D2), the amount of the component (D2) within the resist composition is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A). By ensuring that the amount is within this range, the resist pattern shape and stability over time during storage can be improved.

[0363] <<At least one compound (E) selected from the group consisting of organic carboxylic acids, and phosphorus oxo acids and their derivatives>> The resist composition of this embodiment may contain at least one compound (E) (hereinafter referred to as "component (E)") selected from the group consisting of organic carboxylic acids, and phosphorus oxo acids and their derivatives as an optional component for the purposes of preventing sensitivity degradation and improving resist pattern shape and post-exposure stability. Specific examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, with salicylic acid being preferred. Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred.

[0364] In the resist composition of this embodiment, the component (E) may be used singly, or two or more different components may be used in combination. When the resist composition contains the component (E), the amount of the component (E) per 100 parts by mass of the component (A) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass. By ensuring that the amount is within this range, lithography properties are further improved.

[0365] <Fluorine Additive Component (F)> The resist composition of this embodiment may contain a fluorine additive component (hereafter referred to as "component (F)") as a hydrophobic resin. The component (F) is used to impart water repellency to the resist film, and by using it as a resin separate from component (A), it is possible to improve lithography properties. Examples of component (F) that can be used include the fluorine-containing polymer compounds described in JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, and JP 2011-128226 A. More specific examples of component (F) include polymers having a structural unit (f1) represented by the following general formula (f1-1): This polymer is preferably a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) with the structural unit (a1); or a copolymer of the structural unit (f1) with a structural unit derived from acrylic acid or methacrylic acid and the structural unit (a1), and more preferably a copolymer of the structural unit (f1) with the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl(meth)acrylate or a structural unit derived from 1-methyl-1-adamantyl(meth)acrylate, and more preferably a structural unit derived from 1-ethyl-1-cyclooctyl(meth)acrylate.

[0366] [wherein R is the same as defined above, and Rf １０２ and Rf １０３Rf each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; １０２ and Rf １０３ may be the same or different. １ is an integer of 0 to 5, and Rf １０１ is an organic group containing a fluorine atom.

[0367] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as defined above. R is preferably a hydrogen atom or a methyl group. １０２ and Rf １０３ The halogen atom in Rf is preferably a fluorine atom. １０２ and Rf １０３ Examples of the alkyl group having 1 to 5 carbon atoms in Rf include the same alkyl groups having 1 to 5 carbon atoms as those in R, and a methyl group or an ethyl group is preferred. １０２ and Rf １０３ Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is preferred. Among these, Rf １０２ and Rf １０３ In formula (f1-1), nf is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and still more preferably a hydrogen atom. １ is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0368] In formula (f1-1), Rf １０１is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. In addition, the hydrocarbon group containing a fluorine atom is preferably one in which 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more, because this increases the hydrophobicity of the resist film during immersion exposure. Among these, Rf １０１ is preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, more preferably a trifluoromethyl group, —CH ２ -CF ３ , -CH ２ -CF ２ -CF ３ , -CH(CF ３ ) ２ , -CH ２ -CH ２ -CF ３ , -CH ２ -CH ２ -CF ２ -CF ２ -CF ２ -CF ３ is particularly preferred.

[0369] The weight-average molecular weight (Mw) of component (F) (based on polystyrene standards measured by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. When the Mw is below the upper limit of this range, the component has sufficient solubility in a resist solvent for use as a resist, while when the Mw is above the lower limit of this range, the resulting resist film has good water repellency. The dispersity (Mw / Mn) of component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0370] In the resist composition of this embodiment, the component (F) may be used either as a single type, or as a combination of two or more types. When the resist composition contains the component (F), the amount of the component (F) relative to 100 parts by mass of the component (A) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass.

[0371] <Organic Solvent Component (S)> The resist composition of this embodiment can be produced by dissolving the resist materials in an organic solvent component (hereafter referred to as "component (S)"). In the resist composition of this embodiment, the component (S) may be used alone, or as a mixed solvent of two or more different solvents. Of these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, ethyl lactate (EL), and cyclohexanone are preferred.

[0372] Also preferred as the (S) component is a mixed solvent of PGMEA and a polar solvent. The blending ratio (mass ratio) can be determined appropriately taking into consideration the compatibility of PGMEA with the polar solvent, etc. Also preferred as the (S) component is a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5. The amount of the (S) component is not particularly limited and is appropriately set according to the coating film thickness at a concentration that allows application to a substrate, etc. The (S) component is generally used so that the solids concentration of the resist composition is within the range of 0.1 to 20 mass%, preferably 0.2 to 15 mass%.

[0373] In the resist composition of this embodiment, after dissolving the resist material in component (S), impurities may be removed using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous film, a filter made of a polyamideimide porous film, or a filter made of a polyimide porous film and a polyamideimide porous film. Examples of the polyimide porous film and the polyamideimide porous film include those described in JP 2016-155121 A.

[0374] The resist composition of this embodiment described above contains compound (C) represented by general formula (c0). In the resist composition of this embodiment, the cationic portion of compound (C) contains a thiophene ring and a benzene ring having, as a substituent, one or more electron-withdrawing groups at the ortho- or meta-position. By containing compound (C), the resist composition of this embodiment achieves the effects of high sensitivity and suppressing the occurrence of defects during resist pattern formation. The reason for this effect is presumed to be as follows: By containing a thiophene ring with high electron affinity in the cationic portion of compound (C), the light absorption efficiency during exposure to EUV or other radiation is excellent. Therefore, using a resist composition containing compound (C) improves sensitivity. In addition, by further containing a benzene ring having, as a substituent, one or more electron-withdrawing groups at the ortho- or meta-position, solvent dispersibility is improved. Therefore, using a resist composition containing compound (C) suppresses the occurrence of defects. It is presumed that the above-mentioned effects work synergistically to provide the resist composition of this embodiment with high sensitivity and suppress the occurrence of defects.

[0375] In the resist composition of this embodiment, the compound (C) represented by general formula (c0) can be used as either the component (B) or the component (D).

[0376] (Method of Forming a Resist Pattern) The method of forming a resist pattern pertaining to the second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition pertaining to the first aspect of the present invention, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. One embodiment of the method of forming a resist pattern can be exemplified by a method of forming a resist pattern as follows.

[0377] First, the resist composition of the above-described embodiment is applied to a support using a spinner or the like, and baked (post-applied bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150°C to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an ArF lithography device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with electron beams without a mask pattern. The resist film is then baked (post-exposure bake (PEB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150°C. Next, the resist film is developed. In the case of an alkali development process, the development is performed using an alkaline developer, and in the case of a solvent development process, a developer containing an organic solvent (organic developer) is used.

[0378] After the development treatment, a rinse treatment is preferably carried out. In the case of an alkaline development process, the rinse treatment is preferably a water rinse using pure water, and in the case of a solvent development process, a rinse solution containing an organic solvent is preferably used. In the case of a solvent development process, after the development treatment or rinse treatment, a treatment may be carried out to remove the developer or rinse solution adhering to the pattern using a supercritical fluid. After the development treatment or rinse treatment, drying is carried out. Furthermore, in some cases, a bake treatment (post-bake) may be carried out after the development treatment.

[0379] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, examples include silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold.

[0380] The wavelength used for exposure is not particularly limited, and may be an ArF excimer laser, a KrF excimer laser, or a F ２ Radiation such as excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. The method of forming a resist pattern of this embodiment is particularly useful for a method in which the resist film is exposed to EUV (extreme ultraviolet) or EB (electron beam) in the step of exposing the resist film.

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

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

[0383] Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

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

[0385] The organic developer may contain known additives as needed. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants.

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

[0387] The organic solvent contained in the rinse solution used in the rinsing treatment after development in the solvent development process can be appropriately selected from the organic solvents listed above as organic solvents used in the organic developer, as long as they do not easily dissolve the resist pattern. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used alone or in combination with two or more. They may also be used in combination with other organic solvents or water.

[0388] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method, such as a method of continuously applying the rinse solution onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse solution for a certain period of time (dipping method), or a method of spraying the rinse solution onto the surface of the support (spray method).

[0389] According to the method of forming a resist pattern of the present embodiment as described above, the resist composition described above is used, and therefore when forming a resist pattern, a resist pattern can be formed that has high sensitivity and in which the occurrence of defects is suppressed.

[0390] The resist composition of the above-described embodiment and the various materials used in the pattern formation method of the above-described embodiment (e.g., resist solvent, developer, rinse, anti-reflective coating composition, top coat composition, etc.) preferably do not contain impurities such as metals, halogen-containing metal salts, acids, alkalis, or components containing sulfur or phosphorus atoms. Examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free of impurities (below the detection limit of the measuring device).

[0391] (Compound Represented by General Formula (c0)) The compound according to the third aspect of the present invention is a compound represented by the following general formula (c0) (hereinafter also referred to as "compound (C)").

[0392] [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent. － represents a counter anion.

[0393] The compound (C) represented by the above general formula (c0) is the same as the compound (C) in the resist composition related to the first aspect of the present invention.

[0394] A suitable example of the compound of this embodiment is a compound (C') represented by the following general formula (c0').

[0395] [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. The benzene ring in the formula ０１ The thiophene ring in the formula may have a substituent other than R. ｒ is a benzene ring or a thiophene ring. ｒ is a benzene ring, R ０２ is an electron-withdrawing group; k is an integer from 1 to 5; R ０２ is bonded at least to the ortho or meta position. ｒ is a benzene ring and k is an integer of 2 or more, ０２ may be the same or different. ｒ The benzene ring of R ０２ may have a substituent other than R ｒ is a thiophene ring, R ０２ is a substituent, and k is an integer of 0 to 3. ｒ is a thiophene ring and k is an integer of 2 or more, ０２ may be the same or different. － represents a counter anion.

[0396] The compound represented by the general formula (c0') (compound (C')) is the same as compound (C') in the resist composition according to the first aspect of the present invention. Specific examples of the compound according to this embodiment include compounds in which the cationic moiety is a cation represented by any of the above chemical formulas (c0-ca-1) to (c0-ca-84).

[0397] Further, specific examples of the compound of this embodiment preferably include the compounds represented by the above-mentioned chemical formulas (C0-1) to (C0-12).

[0398] [Method for producing a compound represented by general formula (c0)] Compound (C) can be produced by appropriately combining known methods, as in the <Synthesis Examples of Compounds> shown in the later-described [Examples]. Compound (C) can be produced, for example, by the following reactions (I) to (III).

[0399] <<Reaction (I)>> Reaction (I) is a step of reacting a Grignard reagent with a thionyl halide to obtain a raw material corresponding to the target compound. For example, compound (C0-20) represented by the following general formula (c0-20), compound (C0-21) represented by the following general formula (c0-21), and compound (C0-22) represented by the following general formula (c0-22) are reacted to obtain compound (C0pre-1) represented by the following general formula (c0pre-1) as an intermediate for the target compound.

[0400] [In the formula, X ０１ , j and R ０１ are the same as those in the formula (c0). ０３ is a metal halide. ０２ is a halogen atom.

[0401] In the formulas (c0-20) and (c0-21), R ０３ represents a metal halide, and is preferably a magnesium halide, a lithium halide, a zinc halide, or a samarium halide, more preferably a magnesium halide, and further preferably magnesium bromide. ０２ is a halogen atom, preferably chlorine.

[0402] The temperature condition for reaction (I) is, for example, −10 to 20° C., and the reaction time for reaction (I) is, for example, 1 minute to 4 hours.

[0403] The reaction solvent used in reaction (I) may be an organic solvent or a mixed solvent of an organic solvent and water. Examples of the organic solvent include ketone solvents such as cyclohexanone, methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone; ether solvents such as diethyl ether, t-butyl methyl ether, and diisopropyl ether; halogenated solvents such as tetrahydrofuran, 1,3-dioxolane, dichloromethane, 1,2-dichloroethane, and chloroform; ester solvents such as ethyl acetate and propylene glycol monomethyl ether acetate; cyclohexane, propionitrile, acetonitrile, and mixed solvents thereof.

[0404] <<Reaction (II)>> In reaction (II), a compound (C0pre-1) represented by the following general formula (c0pre-1), which is used as a raw material corresponding to the target compound, is reacted with an optionally substituted thiophene and trifluoromethanesulfonic anhydride to obtain a compound (C0pre-2) represented by the following general formula (c0pre-2), which is used as an intermediate for the target compound. Alternatively, in reaction (II), a compound (C0pre-1) represented by the following general formula (c0pre-1) and R ０１ is reacted with a compound in which the ring is a thiophene ring to obtain a compound (C0pre-2) represented by the following general formula (c0pre-2) as an intermediate for the target compound.

[0405] [In the formula, X ０１ , j, R ０１ The thiophene ring and the benzene ring are the same as those in the formula (c0).

[0406] The temperature condition for reaction (II) is, for example, −10 to 20° C., and the reaction time for reaction (II) is, for example, 1 minute to 4 hours.

[0407] The reaction solvent used in reaction (II) may be an organic solvent or a mixed solvent of an organic solvent and water. Examples of the organic solvent include ketone solvents such as cyclohexanone, methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone; ether solvents such as diethyl ether, t-butyl methyl ether, and diisopropyl ether; halogenated solvents such as tetrahydrofuran, 1,3-dioxolane, dichloromethane, 1,2-dichloroethane, and chloroform; ester solvents such as ethyl acetate and propylene glycol monomethyl ether acetate; toluene, tert-butyl methyl ether, cyclohexane, propionitrile, acetonitrile, and mixed solvents thereof.

[0408] <Reaction (III)> In reaction (III), a compound (C0pre-2) represented by the following general formula (c0pre-2) and a compound (C0-23) represented by the following general formula (c0-23), which are used as raw materials corresponding to the target compound, are reacted to obtain a target compound (C) represented by the following general formula (c0).

[0409] [In the formula, X ０１ , Xc － , j and R ０１ are the same as those in the formula (c0). ＋ is a counter cation.] In formula (c0-23), Xm ＋ is not particularly limited, and examples thereof include metal cations.

[0410] The temperature condition for reaction (III) is, for example, −10 to 40° C., and the reaction time for reaction (I) is, for example, 1 minute to 4 hours.

[0411] The reaction solvent used in reaction (III) may be an organic solvent or a mixed solvent of an organic solvent and water. Examples of the organic solvent include ketone solvents such as cyclohexanone, methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone; ether solvents such as diethyl ether, t-butyl methyl ether, and diisopropyl ether; halogenated solvents such as tetrahydrofuran, 1,3-dioxolane, dichloromethane, 1,2-dichloroethane, and chloroform; ester solvents such as ethyl acetate and propylene glycol monomethyl ether acetate; propionitrile; acetonitrile; and mixed solvents thereof.

[0412] In the above-mentioned method for producing compound (C), after each reaction is completed, the compound in the reaction solution may be isolated and purified. For isolation and purification, a conventionally known method can be used, for example, a suitable combination of concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. The structure of the compound obtained as described above is １ H-nuclear magnetic resonance (NMR) spectroscopy, １３ The compounds can be identified by common organic analysis methods such as C-NMR spectroscopy, etc. The raw materials used in each step may be commercially available or synthesized.

[0413] The compound of this embodiment described above can be used in the production of the resist composition according to the first aspect. The compound of this embodiment can also be used as an acid generator according to the fourth aspect described below and an acid diffusion inhibitor according to the fifth aspect described below.

[0414] (Acid Generator) The acid generator according to the fourth aspect of the present invention contains the following compound (b0).

[0415] [In the formula, M ｂ＋ is a cation represented by the following general formula (c0-ca): － is one or more anions selected from the group consisting of anions represented by any one of the following general formulas (b-an-1), (b-an-2), and (b-an-3):

[0416] [In the formula, X０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent.]

[0417] [In the formula, R １０１ and R １０４ ~R １０８ R are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. １０４ and R １０５ may be bonded to each other to form a ring structure. １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０１ is a divalent linking group containing an oxygen atom or a single bond. １０１ ~V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. １０１ and V １０１ cannot be a single bond at the same time. １０１ ~L １０２ are each independently a single bond or an oxygen atom. １０３ ~L １０５ each independently represents a single bond, —CO— or —SO ２ - is.]

[0418] Examples of the compound (b0) include the same compounds as the compound (b0) in the resist composition related to the first aspect of the present invention described above, and are preferably compounds in which the cation moiety is the cation moiety of the compound (C') described above, and more preferably compounds selected from the compounds represented by the above chemical formulas (C0-1) to (C0-11).

[0419] The acid generator of this embodiment can be used in producing the resist composition according to the first aspect. By incorporating the acid generator of this embodiment in the resist composition, it is possible to achieve high sensitivity and suppress the occurrence of defects during the formation of a resist pattern.

[0420] (Acid Diffusion Controller) The acid diffusion controller according to the fifth aspect of the present invention contains the following compound (d0).

[0421] [In the formula, M ｄ＋ is a cation represented by the following general formula (c0-ca): － is one or more anions selected from the group consisting of anions represented by any one of the following general formulas (d1-an-1), (d1-an-2), and (d1-an-3):

[0422] [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent.]

[0423] [In the formula, Rd １ ~Rd ４ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula, no fluorine atom is bonded to the carbon atom adjacent to the sulfur atom. １ represents a single bond or a divalent linking group.

[0424] Examples of the compound (d0) include the same compound (d0) as in the resist composition related to the first aspect of the present invention, and are preferably compounds in which the cation moiety is the cation moiety of the compound (C'), and more preferably compounds represented by the chemical formula (C0-12) above.

[0425] The acid diffusion controller of this embodiment can be used in the production of the resist composition according to the first aspect. By incorporating the acid diffusion controller of this embodiment in the resist composition, it is possible to achieve high sensitivity and suppress the occurrence of defects during the formation of a resist pattern.

[0426] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0427] <Synthesis Examples of Compounds> [Synthesis Example 1: Synthesis of Compound (C0-1)] A tetrahydrofuran solution of Compound A was prepared by a standard method using 1-bromo-3-trifluoromethylbenzene (96.5 g), magnesium (13.4 g), and tetrahydrofuran (400 g). To this solution, thionyl chloride (28.6 g) and tetrahydrofuran (THF) (50 g) were added at a temperature of −5° C. or lower, and the mixture was stirred at room temperature for 1 hour. Further, ion-exchanged water (500 g) was added at a temperature of 5° C. or lower, and the mixture was stirred for 1 hour. After stirring, ethyl acetate (300 g) was added, the aqueous layer was removed, and the resulting organic layer was washed with ion-exchanged water (300 g). After washing, the organic layer was distilled off, and the resulting residue was recrystallized from cyclohexane to obtain Intermediate A (26.0 g).

[0428]

[0429] Intermediate A (6.86 g) was diluted with thiophene (30 g), and trifluoromethanesulfonic anhydride (8.46 g) was added dropwise at a temperature of -5°C or below, followed by reaction at room temperature for 1 hour. The supernatant was removed, and ion-exchanged water (50 g) was added to the oily precipitate at a temperature of 5°C or below. Then, tetrahydrofuran (THF) (75 g) and toluene (30 g) were added, and the mixture was stirred for 1 hour. The upper layer was removed, and the remaining solution was washed twice with toluene (30 g), neutralized with sodium bicarbonate, extracted with dichloromethane (100 g), the aqueous layer was removed, and the organic layer was further washed with ion-exchanged water (50 g). The organic layer was distilled off, and tert-butyl methyl ether (150 g) was added to the precipitated crystals to obtain white crystals. The crystals were filtered and dried under reduced pressure to obtain Intermediate B (6.53 g).

[0430]

[0431] Intermediate B (5.0 g), compound B (3.9 g), dichloromethane (150 g), and ion-exchanged water (10 g) were stirred at room temperature and separated into layers. The organic layer was washed five times with ion-exchanged water (10 g) and then concentrated under reduced pressure to obtain compound (C0-1) (5.8 g).

[0432]

[0433] The obtained compound (C0-1) was subjected to NMR measurement, and its structure was identified from the analytical results shown below. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 5.10-5.15 (m, 2H), 6.98 (m, 2H), 7.1 9-7.32 (m, 5H), 7.41-7.49 (m, 4H), 8.03-8.12 (m, 2H) 8.03-8.12 (m, 2H)

[0434] Synthesis Example 2 Synthesis of Compound (C0-2) The target compound (C0-2) was obtained in the same manner as in Synthesis Example 1, except that the following compound C was used instead of compound A and the following compound B' was used instead of compound B.

[0435]

[0436] The obtained compound (C0-2) was subjected to NMR measurement, and its structure was identified from the following results.１ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 5.10-5.15 (m, 2H), 7.01 (m, 2H), 7.21-7.34 (m, 5H), 7.45-7.51 (m, 4H), 8.03-8.12 (m, 2H).

[0437] Synthesis Example 3 Synthesis of Compound (C0-3) The target compound (C0-3) was obtained in the same manner as in Synthesis Example 1, except that the following compound D was used instead of compound A.

[0438]

[0439] The obtained compound (C0-3) was subjected to NMR measurement, and its structure was identified from the following results. 　１ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 5.10-5.15 (m, 2H), 6.68-6.75 (m, 6H), 6.98 (m, 2H), 7.25 (d, 1H), 8.03-8.12 (m, 2H).

[0440] Synthesis Example 4 Synthesis of Compound (C0-4) Intermediate C was obtained in the same manner as in the reaction for obtaining intermediate A in Synthesis Example 1, except that compound D below was used instead of compound A.

[0441]

[0442] A solution obtained by diluting compound L (84.3 g) in tetrahydrofuran (300 g) was designated solution (1). Intermediate C (38 g) and tetrahydrofuran (150 g) were placed in a separate container and stirred at room temperature. Trimethylsilyl trifluoromethanesulfonate (125 g) and the above solution (1) were added dropwise thereto. After the dropwise addition, the mixture was stirred at room temperature for 1 hour, dichloromethane (200 g) was added, and the mixture was stirred for an additional 30 minutes, after which the aqueous layer was removed. The organic layer was washed three times with ion-exchanged water (200 g) and then concentrated under reduced pressure. The concentrated residue was crystallized from dichloromethane / tert-butyl methyl ether to obtain intermediate D (13 g) as a white solid.

[0443]

[0444] Intermediate D (5.0 g), compound B (3.9 g), dichloromethane (150 g), and ion-exchanged water (10 g) were stirred at room temperature and separated into layers. The organic layer was washed five times with ion-exchanged water (10 g) and then concentrated under reduced pressure to obtain compound (C0-4) (5.8 g).

[0445]

[0446] The obtained compound (C0-4) was subjected to NMR measurement, and its structure was identified from the following results. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 5.10-5.15 (m, 2H), 6.68-6.75 (m, 6H), 7.02 (d, 2H), 7.20-7.23 (m, 2H), 8.03-8.12 (m, 2H).

[0447] Synthesis Example 5 Synthesis of Compound (C0-5) The target compound (C0-5) was obtained in the same manner as in Synthesis Example 1, except that the following compound E was used instead of compound A.

[0448]

[0449] The obtained compound (C0-5) was subjected to NMR measurement, and its structure was identified from the following results. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 5.10-5.15 (m, 2H), 6.97-7.08 (m, 7H), 7.17-7.23 (m, 3H), 8.03-8.12 (m, 2H).

[0450] Synthesis Example 6 Synthesis of Compound (C0-6) The target compound (C0-6) was obtained in the same manner as in Synthesis Example 1, except that the following compound F was used instead of compound A and 3-fluorothiophene was used instead of thiophene.

[0451]

[0452] The obtained compound (C0-6) was subjected to NMR measurement, and its structure was identified from the following results. １H-NMR (DMSO-d6, 400MHz): δ (ppm) = 5.10-5.15 (m, 2H), 6.91-7.02 (m, 6H), 7.21 (t, 1H), 7.43 (d, 2H), 8.03-8.12 (m, 2H).

[0453] Synthesis Example 7 Synthesis of Compound (C0-7) The target compound (C0-7) was obtained in the same manner as in Synthesis Example 1, except that the following compound G was used instead of compound A and 1,3-difluoro-2-iodobenzene was used instead of thiophene.

[0454]

[0455] The obtained compound (C0-7) was subjected to NMR measurement, and its structure was identified from the following results. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 5.10-5.15 (m, 2H), 6.61 (s, 2H), 6.95-7.12 (m, 4H), 7.21 (d, 2H), 8.03-8.12 (m, 2H).

[0456] Synthesis Example 8 Synthesis of Compound (C0-8) The target compound (C0-8) was obtained in the same manner as in Synthesis Example 1, except that the compound D was used instead of the compound A and the compound H was used instead of thiophene.

[0457]

[0458] The obtained compound (C0-8) was subjected to NMR measurement, and its structure was identified from the following results. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 5.13 (m, 2H), 6.72-6.80 (m, 7H), 8.00-8.11 (m, 2H).

[0459] Synthesis Example 9 Synthesis of Compound (C0-9) The target compound (C0-9) was obtained in the same manner as in Synthesis Example 1, except that Compound D was used instead of Compound A and Compound I was used instead of Compound B.

[0460]

[0461] The obtained compound (C0-9) was subjected to NMR measurement, and its structure was identified from the following results. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 1.45-1.82 (m, 14H), 3.91 (S, 2H), 4.51 (s, 1H), 6.68-6.75 (m, 6H), 6.98 (m, 2H), 7.25 (d, 1H).

[0462] Synthesis Example 10: Synthesis of Compound (C0-10) The target compound (C0-10) was obtained in the same manner as in Synthesis Example 1, except that the following compound J was used instead of compound A and the above compound I was used instead of compound B.

[0463]

[0464] The obtained compound (C0-10) was subjected to NMR measurement, and its structure was identified from the following results. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 1.45-1.82 (m, 14H), 3.91 (S, 2H), 4.51 (s, 1H), 6.95-7.06 (m, 8H), 7.16-7.22 (m, 3H).

[0465] Synthesis Example 11: Synthesis of Compound (C0-11) The target compound (C0-11) was obtained in the same manner as in Synthesis Example 1, except that the following compound K was used instead of compound A and the above compound I was used instead of compound B.

[0466]

[0467] The obtained compound (C0-11) was subjected to NMR measurement, and its structure was identified from the following results. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 1.45-1.82 (m, 14H), 3.91 (S, 2H), 4.51 (s, 1H), 6.98-7.12 (m, 6H), 7.20-7.24 (m, 5H).

[0468] Synthesis Example 12: Synthesis of Compound (C0-12) The target compound (C0-12) was obtained in the same manner as in Synthesis Example 1, except that the following compound M was used instead of compound B.

[0469]

[0470] The obtained compound (C0-12) was subjected to NMR measurement, and its structure was identified from the following results. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 6.98 (m, 2H), 7.19-7.32 (m, 5H), 7.41-7.49 (m, 4H), 7.92-8.12 (m, 2H).

[0471] Synthesis Example 13 Synthesis of Compound (C1-5) The target compound (C1-5) was obtained in the same manner as in Synthesis Example 1, except that the following compound N was used instead of compound A.

[0472]

[0473] The resulting compound (C1-5) was subjected to NMR measurement, and its structure was identified from the following results. １ H-NMR (DMSO-d6, 400MHz): δ (ppm) = 5.10-5.15 (m, 2H), 6.97-7.09 (m, 6H), 7.17-7.23 (m, 5H), 8.03-8.12 (m, 2H).

[0474] <Preparation of Resist Compositions> (Examples 1 to 17, Comparative Examples 1 to 5) The components shown in Tables 1 and 2 were mixed and dissolved to prepare the resist compositions of each example.

[0475]

[0476]

[0477] In Tables 1 and 2, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0478] (A)-1: A polymeric compound represented by the following chemical formula (A1)-1. The weight average molecular weight (Mw) of polymeric compound (A1)-1, calculated in terms of standard polystyrene, determined by GPC measurement, was 5,800, and the molecular weight dispersity (Mw / Mn) was 1.59. １３ The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0479] (A)-2: Polymer compound represented by the following chemical formula (A1)-2. The weight average molecular weight (Mw) of polymer compound (A1)-2, calculated in terms of standard polystyrene, determined by GPC measurement, was 6,300, and the molecular weight dispersity (Mw / Mn) was 1.54. １３ The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0480] (A)-3: Polymer compound represented by the following chemical formula (A1)-3. The weight average molecular weight (Mw) of polymer compound (A1)-3, calculated in terms of standard polystyrene, determined by GPC measurement, was 5,900, and the molecular weight dispersity (Mw / Mn) was 1.57. １３ The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0481] (A)-4: Polymer compound represented by the following chemical formula (A1)-4. The weight average molecular weight (Mw) of polymer compound (A1)-4, calculated in terms of standard polystyrene, determined by GPC measurement, was 5,800, and the molecular weight dispersity (Mw / Mn) was 1.56. １３ The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0482] (A)-5: Polymer compound represented by the following chemical formula (A1)-5. The weight average molecular weight (Mw) of polymer compound (A1)-5, calculated in terms of standard polystyrene, determined by GPC measurement, was 5,600, and the molecular weight dispersity (Mw / Mn) was 1.58. １３ The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0483]

[0484] (B)-1: An acid generator comprising the above compound (C0-1). (B)-2: An acid generator comprising the above compound (C0-2). (B)-3: An acid generator comprising the above compound (C0-3). (B)-4: An acid generator comprising the above compound (C0-4). (B)-5: An acid generator comprising the above compound (C0-5). (B)-6: An acid generator comprising the above compound (C0-6). (B)-7: An acid generator comprising the above compound (C0-7). (B)-8: An acid generator comprising the above compound (C0-8). (B)-9: An acid generator comprising the above compound (C0-9). (B)-10: An acid generator comprising the above compound (C0-10). (B)-11: An acid generator comprising the above compound (C0-11).

[0485] (B)-12: An acid generator comprising the following compound (C1-1). (B)-13: An acid generator comprising the following compound (C1-2). (B)-14: An acid generator comprising the following compound (C1-3). (B)-15: An acid generator comprising the following compound (C1-4). (B)-16: An acid generator comprising the following compound (C1-5).

[0486]

[0487] (D)-1: An acid diffusion controller comprising a compound represented by the following chemical formula (D1-1): (D)-2: An acid diffusion controller comprising a compound represented by the following chemical formula (D1-2): (D)-3: An acid diffusion controller comprising a compound represented by the above chemical formula (C0-12):

[0488]

[0489] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether=60 / 40 (mass ratio).

[0490] <Formation of Resist Pattern> Step of Forming Resist Film: Each resist composition of the examples was applied using a spinner onto an 8-inch silicon substrate that had been treated with hexamethyldisilazane (HMDS), and the applied resist composition was pre-baked (PAB) on a hot plate at a temperature of 110°C for 60 seconds, followed by drying to form a resist film with a thickness of 50 nm.

[0491] Step of exposing resist film: Next, the resist film was subjected to exposure to light 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 (pitch width of 100 nm). Thereafter, post-exposure bake (PEB) treatment was performed at 110°C for 60 seconds.

[0492] Step of developing the exposed resist film: Next, alkaline development was carried out for 60 seconds at 23°C using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, a water rinse was carried out for 15 seconds using pure water. As a result, a 1:1 LS pattern with a line width of 50 nm (pitch width of 100 nm) was formed.

[0493] [Evaluation of Optimal Exposure Dose (Eop)] The optimal exposure dose Eop (μC / cm) for forming an LS pattern of the target size by the above <Formation of Resist Pattern> was ２ This was called "Eop (μC / cm ２ ) are shown in Table 3.

[0494] [Evaluation of Development Defects] The resist patterns obtained by the above <Formation of Resist Pattern> were observed using a surface defect observation device KLA2371 (manufactured by KLA Tencor Corporation). The number of development defects in the unexposed areas per silicon wafer was measured and evaluated according to the following evaluation criteria (A to C). This is shown in Table 3 as "Defect Evaluation". (Evaluation Criteria) A: Less than 1000 B: 1000 to less than 5000 C: 5000 or more

[0495]

[0496] As shown in Table 3, it was confirmed that the resist compositions of Examples 1 to 17 had higher sensitivity and suppressed the occurrence of defects compared to the resist compositions of Comparative Examples 1 to 5.

[0497] More specifically, as shown in Table 3, it was confirmed that the resist composition of Example 9, which contained the compound (C) having a thiophene ring, had higher sensitivity and suppressed the occurrence of defects compared to the resist composition of Comparative Example 4, which contained the compound (C) not having a thiophene ring.

[0498] Furthermore, as shown in Table 3, it was confirmed that the resist compositions of Examples 9 to 11, which contained compound (C) having a benzene ring with one or more electron-withdrawing groups at the ortho- or meta-position as a substituent, had higher sensitivity and suppressed the occurrence of defects compared to the resist composition of Comparative Example 1, which did not have an electron-withdrawing group as a substituent on the benzene ring.

[0499] Furthermore, as shown in Table 3, it was confirmed that the resist compositions of Examples 9 and 10, which contain compound (C) having a benzene ring with an electron-withdrawing group at the meta position as a substituent, have higher sensitivity and suppress the occurrence of defects compared to the resist composition of Comparative Example 2, which contains compound (C) having a benzene ring with an electron-withdrawing group at the para position as a substituent.

[0500] Furthermore, as shown in Table 3, it was confirmed that the resist composition of Example 11, which contains compound (C) having a benzene ring with an electron-withdrawing group at the ortho position as a substituent, has higher sensitivity and suppresses the occurrence of defects compared to the resist composition of Comparative Example 2, which contains compound (C) having a benzene ring with an electron-withdrawing group at the para position as a substituent.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; and a compound (C) that is represented by the following general formula (c0) and generates an acid upon exposure: [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent. － represents a counter anion.

2. The resist composition according to claim 1, wherein the compound (C) is a compound represented by the following general formula (c0'): [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. The benzene ring in the formula ０１ The thiophene ring in the formula may have a substituent other than R. ｒ is a benzene ring or a thiophene ring. ｒ is a benzene ring, R ０２ is an electron-withdrawing group; k is an integer from 1 to 5; R ０２ is bonded at least to the ortho or meta position. ｒ is a benzene ring and k is an integer of 2 or more, ０２ may be the same or different. ｒ The benzene ring of R ０２ may have a substituent other than R ｒ is a thiophene ring, R ０２ is a substituent, and k is an integer of 0 to 3. ｒ is a thiophene ring and k is an integer of 2 or more, ０２ may be the same or different. － represents a counter anion.

3. The resist composition according to claim 1 or 2, comprising: a base component (A) whose solubility in a developer changes due to the action of acid; and an acid generator component (B) that generates acid upon exposure, wherein the acid generator component (B) comprises a compound represented by the following general formula (b0): [In the formula, M ｂ＋ is the cation moiety of the compound (C). － is one or more anions selected from the group consisting of anions represented by any one of the following general formulas (b-an-1), (b-an-2), and (b-an-3): [In the formula, R １０１ and R １０４ ~R １０８ R are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. １０４ and R １０５ may be bonded to each other to form a ring structure. １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０１ is a divalent linking group containing an oxygen atom or a single bond. １０１ ~V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. １０１ and V １０１ cannot be a single bond at the same time. １０１ ~L １０２ are each independently a single bond or an oxygen atom. １０３ ~L １０５ each independently represents a single bond, —CO— or —SO ２ - is.] 4. A resist composition according to claim 1 or 2, comprising: a base component (A) whose solubility in a developer changes due to the action of an acid; an acid generator component (B) that generates an acid upon exposure; and an acid diffusion controller component (D) that controls the diffusion of the acid generated from the acid generator component (B) upon exposure, wherein the acid diffusion controller component (D) comprises a compound represented by the following general formula (d0): [In the formula, M ｄ＋ is the cation moiety of the compound (C). － is one or more anions selected from the group consisting of anions represented by any one of the following general formulas (d1-an-1), (d1-an-2), and (d1-an-3): [In the formula, Rd １ ~Rd ４ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula, no fluorine atom is bonded to the carbon atom adjacent to the sulfur atom. １ represents a single bond or a divalent linking group.

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

6. A compound represented by the following general formula (c0): [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent. － represents a counter anion.

7. The compound according to claim 6, which is a compound represented by the following general formula (c0'): [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. The benzene ring in the formula ０１ The thiophene ring in the formula may have a substituent other than R. ｒ is a benzene ring or a thiophene ring. ｒ is a benzene ring, R ０２ is an electron-withdrawing group; k is an integer from 1 to 5; R ０２ is bonded at least to the ortho or meta position. ｒ is a benzene ring and k is an integer of 2 or more, ０２ may be the same or different. ｒ The benzene ring of R ０２ may have a substituent other than R ｒ is a thiophene ring, R ０２ is a substituent, and k is an integer of 0 to 3. ｒ is a thiophene ring and k is an integer of 2 or more, ０２ may be the same or different. － represents a counter anion.

8. An acid generator containing a compound represented by the following general formula (b0): [In the formula, M ｂ＋ is a cation represented by the following general formula (c0-ca): － is one or more anions selected from the group consisting of anions represented by any one of the following general formulas (b-an-1), (b-an-2), and (b-an-3): [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent.] [In the formula, R １０１ and R １０４ ~R １０８ R are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. １０４ and R １０５ may be bonded to each other to form a ring structure. １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０１ is a divalent linking group containing an oxygen atom or a single bond. １０１ ~V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. １０１ and V １０１ cannot be a single bond at the same time. １０１ ~L １０２ are each independently a single bond or an oxygen atom. １０３ ~L １０５ each independently represents a single bond, —CO— or —SO ２ - is.] 9. An acid diffusion controller comprising a compound represented by the following general formula (d0): [In the formula, M ｄ＋ is a cation represented by the following general formula (c0-ca): － is one or more anions selected from the group consisting of anions represented by any one of the following general formulas (d1-an-1), (d1-an-2), and (d1-an-3): [In the formula, X ０１ is an electron-withdrawing group; j is an integer of 1 to 5; X ０１ When j is an integer of 2 or more, a plurality of X ０１ may be the same or different. ０１ is an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ０１ The thiophene ring in the formula may have a substituent.] [In the formula, Rd １ ~Rd ４ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula, no fluorine atom is bonded to the carbon atom adjacent to the sulfur atom. １ represents a single bond or a divalent linking group.

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