Resist composition, resist pattern formation method, compound, and polymer compound

Abstract

Provided is a resist composition which generates an acid upon exposure to light, and of which the solubility in a developer solution is changed by the action of the acid. The resist composition contains a resin component (A1) of which the solubility in a developer solution is changed by the action of an acid, the resin component (A1) having a structural unit (a0) derived from a compound represented by general formula (a0-m). W0 represents a polymerizable-group-containing group. Each of R01 and R02 independently represents a chain hydrocarbon group that may have a substituent, and R01 and R02 may be bonded to each other to form a ring structure. R03 represents a chain hydrocarbon group that may have a substituent. Each of m0 and n0 independently represents an integer of 0-4, and 2 ≤ m0 + n0 ≤ 8. R04 represents a substituent. p0 represents an integer of 0 to 2(m0 + n0).

Description

Resist composition, method for forming a resist pattern, compound, and polymer compound

[0001] This application claims priority to Japanese Patent Application No. 2024-122670, filed on July 29, 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 plurality of structural units is generally used as the base component in order to improve lithography properties, etc. For example, Patent Document 1 discloses a resist composition containing a resin component having a structural unit that includes an acid-dissociable group composed of a cyclic group and an aryl group.

[0005] International Publication No. 2011 / 040175

[0006] As resist patterns become finer, for example, in EUV and EB lithography, the goal is to form fine patterns of several tens of nanometers. Along with this miniaturization of resist patterns, further improvement of lithography characteristics has become a challenge. As resist pattern dimensions become smaller, it is required to improve lithography characteristics such as sensitivity and roughness without making a trade-off between them. Furthermore, it is also required to improve defects. However, these lithography characteristics are in a trade-off relationship, and it is difficult to satisfy all of these characteristics.

[0007] 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 improves sensitivity and reduces roughness and defects, a method of forming a resist pattern that uses the resist composition, a polymeric compound that can be used to produce the resist composition, and a compound that can be used to synthesize the polymeric compound.

[0008] 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 acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition comprising a resin component (A1) whose solubility in a developer changes due to the action of the acid, and the resin component (A1) has a structural unit (a0) derived from a compound represented by the following general formula (a0-m):

[0009] [In the formula, W ０ represents a polymerizable group-containing group. ０１ and R ０２ each independently represents a chain hydrocarbon group which may have a substituent, R ０１ and R ０２ may be bonded to each other to form a ring structure. ０３ represents a chain hydrocarbon group which may have a substituent. m0 and n0 each independently represent an integer of 0 to 4, and 2≦m0+n0≦8. R ０４ represents a substituent, and p0 represents an integer of 0 or more and 2(m0+n0) or less.

[0010] 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.

[0011] A third aspect of the present invention is a compound represented by the following general formula (a0-m):

[0012] [In the formula, W ０ represents a polymerizable group-containing group. ０１ and R０２ each independently represents a chain hydrocarbon group which may have a substituent, R ０１ and R ０２ may be bonded to each other to form a ring structure. ０３ represents a chain hydrocarbon group which may have a substituent. m0 and n0 each independently represent an integer of 0 to 4, and 2≦m0+n0≦8. R ０４ represents a substituent, and p0 represents an integer of 0 or more and 2(m0+n0) or less.

[0013] A fourth aspect of the present invention is a polymer compound derived from the compound according to the third aspect.

[0014] According to the present invention, it is possible to provide a resist composition that exhibits improved sensitivity and reduced roughness and defects, a method of forming a resist pattern that uses the resist composition, a polymeric compound that can be used to produce the resist composition, and a compound that can be used to synthesize the polymeric compound.

[0015] 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 it is written that "may have a substituent," it means a case where a hydrogen atom (-H) is replaced with a monovalent group, or a case where a methylene group (-CH ２ The term "exposure" encompasses both cases where the radical (-) is substituted with a divalent group.

[0016] 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).

[0017] 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.

[0018] 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).

[0019] 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 αｘ This also includes α-hydroxyacrylic esters in which the α-position carbon atom of an acrylic ester is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group. Unless otherwise specified, the α-position carbon atom of an acrylic ester refers to the carbon atom to which the carbonyl group of 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.

[0020] 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.

[0021] 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.

[0022] (Resist Composition) The resist composition of this embodiment generates 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. The component (A) includes a resin component (A1) whose solubility in a developer changes due to the action of an acid, and the resin component (A1) has a structural unit (a0) derived from a compound represented by general formula (a0-m) above.

[0023] 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.

[0024]

[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.

[0025] 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.

[0026] <Base Component (A)> 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. In the resist composition of this embodiment, the component (A) generates an acid upon exposure. In the resist composition of this embodiment, the component (A1), which will be described later, is preferably a resin that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid.

[0027]

[0043] When a resist film is formed using the resist composition of this embodiment and then subjected to selective exposure, for example, an acid is generated from the component (A) 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.

[0028] 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.

[0029] <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).

[0030] 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.

[0031] 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) has a structural unit (a0) derived from a compound represented by the general formula (a0-m) described below. The component (A1) preferably has a structural unit (a1) containing an acid-decomposable group whose polarity increases under the action of an acid. In addition to the structural unit (a0) and the structural unit (a1), the component (A1) may also contain other structural units as necessary.

[0032] <Structural Unit (a0)> The structural unit (a0) is a structural unit derived from a compound represented by the following general formula (a0-m).

[0033] [In the formula, W ０ represents a polymerizable group-containing group. ０１ and R ０２ each independently represents a chain hydrocarbon group which may have a substituent, R ０１ and R ０２ may be bonded to each other to form a ring structure. ０３ represents a chain hydrocarbon group which may have a substituent. m0 and n0 each independently represent an integer of 0 to 4, and 2≦m0+n0≦8. R ０４ represents a substituent, and p0 represents an integer of 0 or more and 2(m0+n0) or less.

[0034] In the formula (a0-m), W ０ The "polymerizable group" in the polymerizable group-containing group is a group that enables a compound having a polymerizable group to polymerize 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. In the structural unit (a0), the multiple bond in the polymerizable group is cleaved to form a main chain.

[0035] W ０Examples of the polymerizable group in the formula (I) include a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a fluorovinyl group, a difluorovinyl group, a trifluorovinyl group, a difluorotrifluoromethylvinyl group, a trifluoroallyl group, a perfluoroallyl group, a trifluoromethylacryloyl group, a nonylfluorobutylacryloyl group, a vinyl ether group, a fluorine-containing vinyl ether group, an allyl ether group, a fluorine-containing allyl ether group, a styryl group, a vinyl naphthyl group, a fluorine-containing styryl group, a fluorine-containing vinyl naphthyl group, a norbornyl group, a fluorine-containing norbornyl group, and a silyl group.

[0036] 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.

[0037] R Ｘ１１ , R Ｘ１２ and R Ｘ１３ The alkyl group having 1 to 5 carbon atoms in the formula (I) 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. As the halogen atom, a fluorine atom is particularly preferred. Among these, R Ｘ１１ and R Ｘ１２are 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 more preferred, and a hydrogen atom is particularly preferred. Ｘ１３ 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 more preferred, and a hydrogen atom is particularly preferred.

[0038] Ya ｘ０ Examples of the divalent linking group in include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0039] 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 group.

[0040] 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.

[0041] ...Straight-chain or branched-chain aliphatic hydrocarbon groups. The straight-chain aliphatic hydrocarbon groups preferably have 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.

[0042] 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.

[0043] ...Aliphatic hydrocarbon groups containing a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), which may contain 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 within a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as 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.

[0044] 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.

[0045] Aromatic Group: The aromatic group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π-electrons. It may be monocyclic or polycyclic, and may have a substituent substituting a hydrogen atom of the aromatic ring. Examples of aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. The aromatic hydrocarbon ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 5 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent substituting a hydrogen atom of the aromatic hydrocarbon ring. Specific examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, and phenanthrene. Heteroatoms in aromatic heterocycles include oxygen, sulfur, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine and thiophene rings.

[0046] The number of carbon atoms in the aromatic group is preferably 4 to 30, more preferably 4 to 20, still more preferably 4 to 15, and particularly preferably 4 to 12. Specific examples of the aromatic 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 has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl groups or heteroaryl groups), in which one hydrogen atom 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.

[0047] In the aromatic group, a hydrogen atom contained in the aromatic group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic 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 contained in the cyclic aliphatic hydrocarbon group. The halogen atom as the substituent is preferably a bromine atom or an iodine atom, and more preferably an iodine atom.

[0048] 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 an integer of 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.

[0049] Ya ｘ０ As the divalent linking group in the formula (I), a divalent linking group containing a cyclic hydrocarbon group which may have a substituent is preferred, and a divalent linking group containing a hydrocarbon group having at least one aromatic hydrocarbon ring which may have a substituent is more preferred.

[0050] In the formula (a0-m), R ０１ and R ０２ Examples of the chain hydrocarbon group which may have a substituent in the formula (I) include a chain aliphatic hydrocarbon group. The chain aliphatic hydrocarbon group may be saturated or unsaturated. Examples of the chain hydrocarbon group include those having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. Examples of the chain hydrocarbon group include linear or branched alkyl groups, linear or branched alkenyl groups, and linear or branched alkynyl groups.

[0051] The linear alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, even more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms. The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, and still more preferably 3 to 5 carbon atoms. Specific examples of the branched alkyl group 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.

[0052] The linear alkenyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and even more preferably 2 to 4 carbon atoms. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butenyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups.

[0053] R ０１ and R ０２ The chain hydrocarbon group may have a substituent, such as a hydroxy group, an amino group, a cyano group, a halogen atom, or a nitro group.

[0054] The linear alkynyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and even more preferably 2 to 4 carbon atoms. Examples of the linear alkynyl group include a propargyl group and a butynyl group.

[0055] R ０１ and R ０２ may be bonded to each other to form a ring structure. ０１ and R ０２ The ring structure formed by the bonding of the groups is preferably an alicyclic group. The alicyclic group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms, still more preferably 3 to 8 carbon atoms, and particularly preferably 3 to 6 carbon atoms.

[0056] The alicyclic group may be a polycyclic group or a monocyclic group, with a monocyclic group being preferred. The alicyclic group may be saturated or unsaturated. The monocyclic alicyclic group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane, or a group obtained by removing one or more hydrogen atoms from a monocycloalkene. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cycloheptane. The monocycloalkene preferably has 3 to 6 carbon atoms, and specific examples include cyclopropene, cyclobutene, cyclopentene, cyclohexene, and cycloheptene. The polycyclic alicyclic group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a polycyclic skeleton of a fused ring system, such as a cyclic group having a steroid skeleton.

[0057] R ０１ and R ０２ The alicyclic group formed by bonding together may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, an acyl group, a halogenated alkyl group, a hydroxy group, an amino group, a cyano group, a halogen atom, and a nitro group. The alkyl group, alkoxy group, acyl group, and halogenated alkyl group as the substituent may be linear or branched. The alkyl group, alkoxy group, acyl group, and halogenated alkyl group may have 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms.

[0058] R ０１ and R ０２are preferably bonded to each other to form a ring structure. The ring structure is more preferably an alicyclic group, more preferably a monocycloalkyl group, still more preferably a monocycloalkyl group having 3 to 8 carbon atoms, and particularly preferably a cyclopentyl group.

[0059] In the formula (a0-m), R ０３ The chain hydrocarbon group which may have a substituent in R ０１ and R ０２ Examples of the chain hydrocarbon group include the same as the optionally substituted chain hydrocarbon group in the above.

[0060] In the formula (a0-m), m0 and n0 preferably satisfy 2≦m0+n0≦6, more preferably 2≦m0+n0≦5, further preferably 2≦m0+n0≦4, and particularly preferably m0+n0=3. ０１ and R ０２ It is particularly preferred that the ring structure formed by bonding together is a five-membered alicyclic group.

[0061] In the formula (a0-m), R ０４ Examples of the substituent in the above formula (I) include an alkyl group, an alkoxy group, an acyl group, a halogenated alkyl group, a hydroxy group, an amino group, a cyano group, a halogen atom, and a nitro group. The alkyl group, alkoxy group, acyl group, and halogenated alkyl group as the substituent may be linear or branched. The alkyl group, alkoxy group, acyl group, and halogenated alkyl group may have 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms.

[0062] In the formula (a0-m), p0 is preferably an integer of 0 to 4, more preferably an integer of 0 to 2, and even more preferably 0 or 1.

[0063] The structural unit (a0) is preferably a structural unit represented by the following general formula (a0-1) or (a0-2).

[0064] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ and R０２ each independently represents a chain hydrocarbon group which may have a substituent, R ０１ and R ０２ may be bonded to each other to form a ring structure. ０３ represents a chain hydrocarbon group which may have a substituent. m0 and n0 each independently represent an integer of 0 to 4, and 2≦m0+n0≦8. Y ０１ represents a divalent linking group. k0 represents an integer of 0 to 2. ０ represents an aromatic hydrocarbon group which may have a substituent. ０２ represents a single bond or a divalent linking group. ０４ represents a substituent, and p0 represents an integer of 0 or more and 2(m0+n0) or less.

[0065] In the formulas (a0-1) and (a0-2), R ０１ ~R ０４ , m0, n0, and p0 are R in the formula (a0-m). ０１ ~R ０４ , m0, n0, and p0, respectively.

[0066] In the formulas (a0-1) and (a0-2), 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. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. 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.

[0067] In the formula (a0-1), Y ０１ As the divalent linking group in ｘ０ The divalent linking group in Y ０１is preferably a cyclic group, and more preferably an alicyclic group or an aromatic hydrocarbon group. The alicyclic group is a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7) described below, or an —SO 2 group represented by each of the general formulae (b5-r-1) to (b5-r-4) described below. ２ -containing cyclic groups, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) described below.

[0068] In the formula (a0-1), k0 is preferably 0 or 1.

[0069] In the formula (a0-2), Wa ０ As the aromatic hydrocarbon group in ｘ０ The aromatic hydrocarbon group may be the same as the aromatic hydrocarbon group in the divalent linking group of Wa. ０ The aromatic hydrocarbon group in is preferably a group in which two hydrogen atoms have been removed from an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, or phenanthrene, and more preferably a group in which two hydrogen atoms have been removed from benzene.

[0070] In the formula (a0-2), Wa ０ The aromatic hydrocarbon group in the formula (I) may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, an acyl group, a halogenated alkyl group, a hydroxy group, an amino group, a cyano group, a halogen atom, and a nitro group. The alkyl group, alkoxy group, acyl group, and halogenated alkyl group as the substituent may be linear or branched. The alkyl group, alkoxy group, acyl group, and halogenated alkyl group may have 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms. Examples of the halogen atom as the substituent include a fluorine atom, an iodine atom, and a bromine atom, with an iodine atom being preferred.

[0071] In the formula (a0-2), Y ０２ As the divalent linking group in ｘ０ The divalent linking group in Y ０２ As the divalent linking group in２１ -(Y ２１ In the above formula, —C(═O)— is preferably a group represented by Wa in the above formula (a0-2). ０ Combine with Y ２１ As the hydrocarbon group in ｘ０ The hydrocarbon group may have a substituent, and may be the same as the hydrocarbon group in the divalent linking group of Y. ２１ is preferably a cyclic group, and more preferably an alicyclic group or an aromatic hydrocarbon group. The alicyclic group is a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7) described below, or an —SO 2 group represented by each of the general formulae (b5-r-1) to (b5-r-4) described below. ２ -containing cyclic groups, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) described below.

[0072] Specific examples of the structural unit (a0) include, but are not limited to, the following: α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] The structural unit (a0) contained in the component (A1) may be of one type, or may be of two or more types. The proportion of the structural unit (a0) in the component (A1), relative to the total (100 mol%) of all structural units constituting 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%. When the proportion of the structural unit (a0) is at least the lower limit of the above-mentioned preferred range, roughness and defects are likely to be reduced while maintaining good sensitivity. When the proportion of the structural unit (a0) is at most the upper limit of the above-mentioned preferred range, a balance with the other structural units can be achieved, and various lithography properties are improved.

[0086] <<Other Structural Units>> The component (A1) may include other structural units in addition to the structural unit (a0) described above. Examples of other structural units include the structural unit (a1) (excluding those corresponding to the structural unit (a0)) containing an acid-decomposable group whose polarity increases when acted upon by acid, the structural unit (a10) represented by the general formula (a10-1) described below, the structural unit (a2) containing a lactone-containing cyclic group, the structural unit (a5) that generates acid upon exposure, the structural unit (a6) that has acid diffusion-controlling properties, and the structural unit (a8) derived from a compound represented by the general formula (a8-1) described below.

[0087] 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, with the proviso that structural units (a1) that fall under the category of structural unit (a0) are excluded.

[0088] 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 alkyl ester-type acid-dissociable groups" described below.

[0089] 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"):

[0090] [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.]

[0091] In formula (a1-r-1), Ra' １ and Ra' ２ Among Ra', at least one is preferably a hydrogen atom, and more preferably both are hydrogen atoms. １ or Ra' ２ When is an alkyl group, examples of the alkyl group include the same alkyl groups as those exemplified as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester above, and alkyl groups having 1 to 5 carbon atoms are preferred. Specific examples include linear or branched alkyl groups. More specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. A methyl group or an ethyl group is more preferred, and a methyl group is particularly preferred.

[0092] 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.

[0093] 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.

[0094] Ra' ３ When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic 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.

[0095] Ra' ３When the cyclic hydrocarbon group described above is an aromatic group, the aromatic group is a group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. It may be monocyclic or polycyclic, and may have a substituent substituting a hydrogen atom of the aromatic ring. Examples of aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles in which a portion of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. 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 5 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent substituting a hydrogen atom of the aromatic hydrocarbon ring. Specific examples of aromatic rings include benzene, naphthalene, anthracene, and phenanthrene. 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.

[0096] Ra' ３ The aromatic group in the formula (I) preferably has 4 to 30 carbon atoms, more preferably 4 to 20 carbon atoms, still more preferably 4 to 15 carbon atoms, and particularly preferably 4 to 12 carbon atoms.

[0097] Ra' ３ Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or the 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 the 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 the aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0098] Ra'３ The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R Ｐ１ , -R Ｐ２ -O-R Ｐ１ , -R Ｐ２ -CO-R Ｐ１ , -R Ｐ２ -CO-OR Ｐ１ , -R Ｐ２ -O-CO-R Ｐ１ , -R Ｐ２ -OH, -R Ｐ２ -CN or -R Ｐ２ -COOH (hereinafter, these substituents are collectively referred to as "Ra ｘ５ ") etc. Here, R Ｐ１ is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic group having 4 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 group having 4 to 30 carbon atoms. Ｐ１ and R Ｐ２ Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group, and the aromatic group may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of one type of the above-mentioned substituents, or may have one or more of each of two or more types of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.0]octanyl group, and the like. ２，６ ]decanyl group, tricyclo[3.3.1.1 ３，７ ] decanyl group, tetracyclo[6.2.1.1 ３，６ .0 ２，７] Examples of the monovalent aromatic group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0099] 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.

[0100] 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.

[0101] [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.

[0102] 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' ３The same can be mentioned.

[0103] 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).

[0104] [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 １０３ are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. １０１ ~Ra １０３ Two or more of the above may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ In formula (a1-r2-4), Ra′ is an aromatic 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. １４is a hydrocarbon group which may have a substituent. * indicates a bond (the same applies hereinafter).

[0105] 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.

[0106] 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.

[0107] Ra' １０ In the above, the alkyl group may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Furthermore, some of the carbon atoms (such as methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -S-, and -S(=O) ２ -, -S(=O) ２ -O- and the like.

[0108] 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.

[0109] 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 １０３ In 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.

[0110] 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.

[0111] Ra １０１ ~Ra １０３Examples 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.

[0112] 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. １０４ Examples of the aromatic group in the formula (I) include aromatic groups having 4 to 30 carbon atoms, preferably aromatic groups having 4 to 15 carbon atoms, and include, for example, groups in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring or an aromatic heterocyclic ring. 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, phenanthrene, or thiophene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or thiophene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or thiophene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0113] 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.

[0114] 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' １３In 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.

[0115] In formula (a1-r2-4), Ra' １４ is a hydrocarbon group which may have a substituent. １４ The hydrocarbon group in the formula (I) includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0116] 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.

[0117] 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.

[0118] Ra' １４When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic 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.

[0119] Ra' １４ As the aromatic group in １０４ Among them, the aromatic groups Ra' are the same as those in １４ is an aromatic group having 4 to 15 carbon atoms, 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.

[0120] 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.

[0121] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0122]

[0123]

[0124]

[0125] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0126]

[0127]

[0128]

[0129] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0130]

[0131] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0132]

[0133] 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").

[0134] [In the formula, Ra' ７ ~Ra' ９ are each an alkyl group.

[0135] 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.

[0136] 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).

[0137] [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.

[0138] In the formula, Ra' １０ and Ra' １２ The 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.

[0139] 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.

[0140] Ra' １０ and Ra' １１ａ or Ra' １１ｂand 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.

[0141] 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.

[0142] 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.

[0143] Ra' １１ａ or 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.

[0144] Specific examples of the group represented by the formula (a1-r-4) are listed below.

[0145]

[0146] 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.

[0147] 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):

[0148] [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.

[0149] 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.

[0150] In the formula (a1-1), Va １ The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic group.

[0151] 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.

[0152] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0153] 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.

[0154] Va １The aromatic group as a divalent hydrocarbon group in the formula (I) is a hydrocarbon group having at least one aromatic ring. Such an aromatic group preferably has 3 to 30 carbon atoms, more preferably 4 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 contained in the aromatic 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 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.

[0155] 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.

[0156] In the formula (a1-2), Wa １ (n ａ２The hydrocarbon group having a valence of +1 may be an aliphatic hydrocarbon group or an aromatic group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that combines a linear or branched aliphatic hydrocarbon group with an aliphatic hydrocarbon group containing a ring in its structure. ａ２ The +1 valence 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).

[0157] 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.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] 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 Rz ０１ In addition, in the naphthalene, Ya ００１ , -Ya ０１ -C(=O)-O-Rax ０１ group, and Rz ０１ The substitution position of is not particularly limited.

[0162] 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.

[0163]

[0164]

[0165]

[0166]

[0167]

[0168]

[0169]

[0170]

[0171]

[0172] 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.

[0173]

[0174]

[0175]

[0176]

[0177]

[0178] 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.

[0179] Alternatively, the structural unit (a1) may include a structural unit represented by the following general formula (a1-1-1):

[0180] [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.]

[0181] 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:

[0182] 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.

[0183] 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 or above the lower limit of the aforementioned preferred range, lithography properties such as sensitivity, resolution, and CDU improvement are improved. On the other hand, by ensuring that the proportion is at or below the upper limit of the aforementioned preferred range, a balance with other structural units can be achieved, resulting in various favorable lithography properties. Since the component (A1) contains the structural unit (a0), it does not necessarily need to contain the structural unit (a1).

[0184] Structural Unit (a10): The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0185] [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 group. ａｘ１ is an integer of 1 or greater.

[0186] 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.

[0187] 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.

[0188] 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 group.

[0189] 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.

[0190] ...Straight-chain or branched-chain aliphatic hydrocarbon groups. The straight-chain aliphatic hydrocarbon groups preferably have 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 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.

[0191] 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.

[0192] ...Aliphatic hydrocarbon groups containing a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), which may contain 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 within a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as 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.

[0193] 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.

[0194] Aromatic Group: The aromatic group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π-electrons. It may be monocyclic or polycyclic, and may have a substituent substituting a hydrogen atom of the aromatic ring. Examples of aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. The aromatic hydrocarbon ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 5 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent substituting a hydrogen atom of the aromatic hydrocarbon ring. Specific examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, and phenanthrene. Heteroatoms in aromatic heterocycles include oxygen, sulfur, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine and thiophene rings.

[0195] The number of carbon atoms in the aromatic group is preferably 4 to 30, more preferably 4 to 20, still more preferably 4 to 15, and particularly preferably 4 to 12. Specific examples of the aromatic 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 has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl groups or heteroaryl groups), in which one hydrogen atom 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.

[0196] The aromatic group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic 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.

[0197] 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.

[0198] 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)-].

[0199] In the formula (a10-1), Wa ｘ１ is an aromatic group. ｘ１ The aromatic 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 ｘ１ The aromatic group in (n) is selected from aromatic compounds containing an aromatic ring which may have two or more substituents (for example, biphenyl, fluorene, etc.). ａｘ１Also 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.

[0200] Wa ｘ１ The aromatic 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.

[0201] 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.

[0202] 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.

[0203]

[0204]

[0205]

[0206] 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.

[0207] 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.

[0208] 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).

[0209] [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).

[0210] 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 formula Ra′, ２１ Examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0211] 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.

[0212] Ra' ２１ Among the above, each of the groups is preferably independently a hydrogen atom or a cyano group.

[0213] 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.

[0214] Specific examples of the groups represented by general formulae (a2-r-1) to (a2-r-7) are listed below.

[0215]

[0216]

[0217] 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):

[0218] [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.

[0219] 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.

[0220] 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.

[0221] 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.

[0222] In the formula (a2-1), Ya ２１ is a single bond, and La ２１ is preferably —COO— or —OCO—.

[0223] 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.

[0224] 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.

[0225] 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):

[0226] [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.

[0227] {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.

[0228] 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. ５０is 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)—].

[0229] 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 group.

[0230] .Ra ５０ The aliphatic hydrocarbon group in the above means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0231] ...Straight-chain or branched-chain aliphatic hydrocarbon groups. The straight-chain aliphatic hydrocarbon groups preferably have 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(CH３ ) 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.

[0232] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, which may include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0233] ...Aliphatic hydrocarbon groups containing a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), which may contain 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.

[0234] 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.

[0235] .Ra ５０The aromatic group in the formula (I) is a group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π-electrons. It may be monocyclic or polycyclic, and may have a substituent substituting a hydrogen atom of the aromatic ring. Examples of the aromatic ring include an aromatic hydrocarbon ring and an aromatic heterocycle in which a portion of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with a heteroatom. The aromatic hydrocarbon ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 5 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent substituting a hydrogen atom of the aromatic hydrocarbon ring. Specific examples of aromatic rings include benzene, naphthalene, anthracene, and phenanthrene. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include a pyridine ring and a thiophene ring.

[0236] The number of carbon atoms in the aromatic group is preferably 4 to 30, more preferably 4 to 20, still more preferably 4 to 15, and particularly preferably 4 to 12. Specific examples of the aromatic group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or the 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 has been removed from the aromatic hydrocarbon ring or the aromatic heterocycle (aryl groups or heteroaryl groups), in which one hydrogen atom 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.

[0237] The aromatic group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic 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 substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0238] 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 group.

[0239] n ａ５ If is 2, then two Ra ５０ may all be alicyclic hydrocarbon groups which may have a substituent, may all be aromatic groups, or may be a combination of alicyclic hydrocarbon groups which may have a substituent and aromatic groups.

[0240] In the formula (a5-1), La ５１ is a divalent linking group. ５１ Examples 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 ２Examples 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.

[0241] [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.

[0242] 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.

[0243] V' １０１ and V' １０２ The alkylene group in V' may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group. １０１ and V' １０２ Specific examples of the alkylene group in ２ -]; -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; ethylene groups [-CH ２ CH ２ -]; -CH(CH ３ ) CH ２-, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, etc.; a trimethylene group (n-propylene group) [—CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ an alkyltrimethylene group such as -; a tetramethylene group [-CH ２ CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ -, etc.; an alkyltetramethylene group such as a pentamethylene group [—CH ２ CH ２ CH ２ CH ２ CH ２ -]. Also, V' １０１ or V' １０２ In the formula (a1-r-1), some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by Ra' in the formula (a1-r-1). ３ A divalent group obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group) of the above formula (I) is preferred, and a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferred.

[0244] La ５１As 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 formulas (L-a1-1) to (L-a1-5) and (L-a1-8) are more preferable, and the linking group represented by the above formula (L-a1-3) or (L-a1-8) is even more preferable.

[0245] 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.

[0246] 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 ５２ From the viewpoint of acid strength, it is preferable that at least one of the groups is a fluorine atom.

[0247] In the formula (a5-1), n5 represents an integer of 1 to 4, and is preferably 1, 2, or 3.

[0248] {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.

[0249] Preferred cationic moieties ((M' ｍ＋ ) １／ｍ ) includes organic cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[0250] [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 4 which may have a substituent. ２ -containing cyclic group. ２０１ represents —C(═O)— or —C(═O)—O—.]

[0251] 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 ２０７ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２０１ ~R ２０７ , and R ２１０Examples 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):

[0252] [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.

[0253] 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 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.

[0254] R' ２０１ The aromatic group in the formula (I) 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. It may be monocyclic or polycyclic, and may have a substituent substituting a hydrogen atom on the aromatic ring. Examples of the aromatic ring include an aromatic hydrocarbon ring and an aromatic heterocycle in which a portion of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with a heteroatom. The aromatic hydrocarbon ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 5 to 15 carbon atoms, particularly preferably 6 to 12 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 substituting a hydrogen atom on the aromatic hydrocarbon ring. Specific examples of aromatic hydrocarbon rings include benzene, fluorene, naphthalene, anthracene, phenanthrene, and biphenyl. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

[0255] The aromatic group preferably has 4 to 30 carbon atoms, more preferably 4 to 25 carbon atoms, even more preferably 4 to 20 carbon atoms, particularly preferably 4 to 15 carbon atoms, and most preferably 4 to 10 carbon atoms. ２０１ Specific examples of the aromatic hydrocarbon group in the formula (I) include groups in which one hydrogen atom has been removed from the aromatic ring (aryl groups: for example, phenyl group, naphthyl group, etc.), and groups in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0256] 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.

[0257] Among them, R' ２０１ The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0258] 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.

[0259] 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 represented by the below-described general formulae (b5-r-1) to (b5-r-4), ２ -containing cyclic groups, and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16).

[0260]

[0261] 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

[0262] 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.

[0263] 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 2 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, a linear alkenyl group is preferred, a vinyl group or a propenyl group is more preferred, and a vinyl group is particularly preferred.

[0264] 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:

[0265] 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.

[0266] 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.

[0267] 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.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0268] 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.

[0269] 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 4 which may have a substituent. 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.

[0270] [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.

[0271] 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.

[0272] 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.

[0273] 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.

[0274]

[0275]

[0276]

[0277] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas.

[0278]

[0279]

[0280] [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.]

[0281]

[0282]

[0283] [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

[0284]

[0285]

[0286]

[0287] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0288] 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).

[0289]

[0290] In the formula (a5-1), the cation moiety ((M' ｍ＋ ) １／ｍ) is preferably a sulfonium cation, more preferably at least one selected from the group consisting of cations represented by the general formulas (ca-1) to (ca-3), and among these, the cation represented by the general formula (ca-1) is even more preferable, and specific examples include the cations represented by the formulas (ca-1-1) to (ca-1-104).

[0291] In particular, from the viewpoint of increasing sensitivity and reducing roughness, the cationic moiety is preferably a cation represented by the formula (ca-1), preferably one having an electron-withdrawing group such as a halogen atom, a halogenated alkyl group, or a sulfonyl group as a substituent, and preferably an m-valent organic cation having a halogen atom as a substituent, more preferably one having at least one selected from the group consisting of a halogen atom and a halogenated alkyl group, particularly preferably one having at least one selected from the group consisting of a fluorine atom, an iodine atom, a bromine atom, and a fluorinated alkyl group, and most preferably one having at least one selected from the group consisting of a fluorine atom, an iodine atom, and a fluorinated alkyl group. The halogenated alkyl group may be linear or branched. The halogenated alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms. The halogenated alkyl group is preferably a trifluoromethyl group.

[0292] The cation moiety ((M' ｍ＋ ) １／ｍ ) is particularly preferably a cation represented by the following general formula (ca-h-1).

[0293] [wherein, Rf ２０１ ~Rf ２０３ Rf 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 ~Rf ２０３ may be bonded to each other to form a ring together with the sulfur atom in the formula. ２０１ ~Rf ２０３ At least one of the groups has at least one halogen atom.

[0294] Rf in the formula (ca-h-1) ２０１ ~Rf ２０３ represents R in the formula (ca-1). ２０１ ~R ２０３ and the same as above, except that Rf ２０１ ~Rf ２０３ At least one of Rf has at least one halogen atom. The halogen atom is preferably at least one selected from the group consisting of fluorine atoms, iodine atoms, and bromine atoms, and more preferably at least one selected from the group consisting of fluorine atoms and iodine atoms. The cation represented by formula (ca-h-1) preferably contains three or more halogen atoms, more preferably four or more halogen atoms, even more preferably five or more halogen atoms, and particularly preferably six or more halogen atoms. ２０１ ~Rf ２０３ may have three or more halogen atoms, and Rf ２０１ ~Rf ２０３ The total number of halogen atoms contained in Rf may be three or more. ２０１ ~Rf ２０３ is preferably an aryl group which may have a substituent, more preferably an aryl group having a substituent containing a halogen atom. The substituent containing a halogen atom is preferably at least one selected from the group consisting of a halogen atom and a halogenated alkyl group, more preferably at least one selected from the group consisting of a fluorine atom, an iodine atom and a fluorinated alkyl group, even more preferably at least one selected from the group consisting of a fluorine atom, an iodine atom and a trifluoromethyl group, and particularly preferably at least one selected from the group consisting of a fluorine atom and an iodine atom. As such a cation moiety, a cation selected from the group consisting of the cations represented by the above chemical formulas (ca-1-44) and (ca-1-71) to (ca-1-104) is particularly preferred.

[0295] 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:

[0296]

[0297]

[0298]

[0299]

[0300] 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.

[0301] 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.

[0302] Specific preferred examples of the structural unit (a6) 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:

[0303]

[0304] 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.

[0305] 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).

[0306] [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 R 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.

[0307] W ２ The "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.

[0308] 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.

[0309] 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.

[0310] Specific examples of the structural unit (a8) are shown below. α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0311]

[0312] 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).

[0313] 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).

[0314] The resist composition may contain one type of component (A1), or two or more types of components may be used in combination.

[0315] Examples of the component (A1) include a polymeric compound having the structural unit (a1) and the structural unit (a10); a polymeric compound having the structural unit (a1), the structural unit (a10), and the structural unit (a0); 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); a polymeric compound consisting of the structural unit (a1), the structural unit (a10), and the structural unit (a0); a polymeric compound consisting of the structural unit (a1), the structural unit (a10), and the structural unit (a2).

[0316] 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%, even more preferably 30 to 60 mol%, and particularly preferably 20 to 50 mol%.

[0317] In a polymeric compound comprising the structural unit (a1), the structural unit (a10), and the structural unit (a0), 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%, even more preferably 30 to 60 mol%, and particularly preferably 20 to 50 mol%, relative to the total (100 mol%) of all structural units constituting the polymeric compound. The proportion of the structural unit (a0) in the polymeric compound is preferably 1 to 50 mol%, more preferably 3 to 30 mol%, even more preferably 5 to 20 mol%, and particularly preferably 5 to 15 mol%, relative to the total (100 mol%) of all structural units constituting the polymeric compound.

[0318] In a polymeric compound comprising 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%, even more preferably 30 to 60 mol%, and particularly preferably 20 to 50 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%, even more preferably 10 to 40 mol%, and particularly preferably 10 to 30 mol%, relative to the total (100 mol%) of all structural units constituting the polymeric compound.

[0319] The component (A1) can be produced by dissolving monomers from which each structural unit is derived in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601), followed by polymerization. Examples of monomers from which each structural unit is derived include monomers from which structural unit (a10) is derived, monomers from which structural unit (a1), and monomers from which other optional structural units are derived (e.g., structural unit (a4), structural unit (st), etc.). These monomers (e.g., monomers from which structural unit (a10) is derived) may have protected hydroxyl groups, etc., as necessary. In this case, the component (A1) can be produced by carrying out the polymerization reaction as described above, followed by a deprotection reaction. During 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).

[0320] 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.

[0321] Regarding the component (A2), the resist composition of this embodiment may also use, as the component (A), a base component (hereafter referred to as "component (A2)") that does not fall under the category of the component (A1) above and whose solubility in a developer changes upon 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.

[0322] The proportion of the component (A1) within the component (A), relative to the total mass of the component (A), is preferably 25 mass% or more, more preferably 50 mass% or more, and even more preferably 75 mass% or more, and may even be 100 mass%. When this proportion is 25 mass% or more, sensitivity is likely to be improved and a resist pattern that is excellent in various lithography properties such as resolution and roughness is likely to be formed.

[0323] 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.

[0324] <Acid Generator Component (B)> The resist composition of this embodiment may contain an acid generator component (B) that generates an acid upon exposure. The component (B) is not particularly limited, and 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.

[0325] Examples of the onium salt acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)"):

[0326] [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 m is an integer of 1 or more, and M' ｍ＋ is an m-valent onium cation.

[0327] {Anion moiety} In the anion formula (b-1) of the component (b-1), R １０１ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0328] 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 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.

[0329] R １０１ The aromatic group in (I) 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. It may be monocyclic or polycyclic, and may have a substituent substituting a hydrogen atom on the aromatic ring. Examples of aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles in which a portion of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. The aromatic hydrocarbon ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 5 to 25 carbon atoms, particularly preferably 6 to 12 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 substituting a hydrogen atom on the aromatic hydrocarbon ring. Specific examples of aromatic hydrocarbon rings include benzene, fluorene, naphthalene, anthracene, phenanthrene, and biphenyl. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

[0330] The aromatic group preferably has 4 to 30 carbon atoms, more preferably 4 to 25 carbon atoms, even more preferably 4 to 20 carbon atoms, particularly preferably 4 to 15 carbon atoms, and most preferably 4 to 10 carbon atoms. １０１Specific examples of the aromatic 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.

[0331] R １０１ 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.

[0332] Among them, R １０１The 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.

[0333] 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 CH２ -, -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.

[0334] 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.

[0335] R １０１Examples 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

[0336] R １０１ The 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-1) include groups represented by the following formulae (r-br-1) and (r-br-2). １０１ represents a bond bonded to

[0337]

[0338] R １０１Examples 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 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 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, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of the alicyclic hydrocarbon group as a substituent of the fused cyclic group include a group in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ 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.

[0339] A chain alkyl group which may have a substituent: R １０１The 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.

[0340] 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.

[0341] R １０１ 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, and the R １０１ Examples of the cyclic groups include the cyclic groups shown in the formula:

[0342] In formula (b-1), Y １０１ is a single bond or a divalent linking group containing an oxygen atom. １０１ is a divalent linking group containing an oxygen atom, １０１may 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 formulae (L-a1-1) to (L-a1-8). In the above general formulae (L-a1-1) to (L-a1-8), R in the above formula (b-1) １０１ The group that bonds to V' in the above general formulae (L-al-1) to (L-al-8) is １０１ is.

[0343] In formula (b-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.

[0344] In formula (b-1), R １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. １０２ is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0345] Specific examples of the anion moiety represented by the formula (b-1) include, for example, Y １０１ When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; １０１ When is a divalent linking group containing an oxygen atom, examples of the anion include those represented by any one of the following formulae (an-1) to (an-3).

[0346] [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. １０２represents 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.

[0347] R” １０１ , R” １０２ and R” １０３ The aliphatic cyclic group which may have a substituent is represented by R １０１ The substituent is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in the formula (b-1). １０１ Examples of the substituents that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1).

[0348] R” １０１ and R” １０３ The aromatic cyclic group which may have a substituent in the formula (b-1) is R １０１ The substituent is preferably a group exemplified as an aromatic group in the cyclic hydrocarbon group in the formula (b-1). １０１ Examples of the substituents that may substitute the aromatic group in the above formula (I) include the same as those that may substitute the aromatic group in the above formula (I).

[0349] R” １０１ The chain alkyl group which may have a substituent in the formula (b-1) is R １０１ R" is preferably a group exemplified as a chain alkyl group in １０３The chain alkenyl group which may have a substituent is R １０１ Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0350] In the anionic formula (b-2) of the component (b-2), R １０４ , R １０５ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is represented by R １０１ However, R １０４ , R 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 １０５ In the chain alkyl group, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the improved transparency to high-energy light of 250 nm or less and electron beams, which is preferable. The proportion of fluorine atoms in the chain alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V １０２ , V １０３ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-1). １０１ In formula (b-2), L １０１ , L １０２are each independently a single bond or an oxygen atom.

[0351] In the anionic formula (b-3) of the component (b-3), R １０６ ~R １０８ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is represented by R １０１ In formula (b-3), L １０３ ~L １０５ each independently represents a single bond, —CO— or —SO ２ - is.

[0352] Of the above, the anion moiety of component (B) is preferably the anion in component (b-1), and more preferably the anion represented by formula (an-1).

[0353] {Cation Moiety} In the formula (b-1), formula (b-2), and formula (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.

[0354] The cation moiety of 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-1-104). In particular, from the viewpoints of increasing sensitivity and reducing roughness, the cation moiety of component (B) is more preferably a cation represented by the general formula (ca-h-1) above, and particularly preferably a cation selected from the group consisting of the cations represented by each of the chemical formulas (ca-1-44) and (ca-1-71) to (ca-1-104).

[0355] 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.

[0356] <Base Component (D)> In addition to the component (A), the resist composition of this embodiment may contain a base component (component (D)) that traps acid generated upon exposure (i.e., controls the diffusion of acid). The component (D) acts as a quencher (acid diffusion controller) that traps acid generated in the resist composition upon exposure. Examples of the component (D) include a photodegradable base (D1) (hereinafter referred to as “component (D1)”) that decomposes upon exposure and loses its ability to control acid diffusion, and a nitrogen-containing organic compound (D2) (hereinafter referred to as “component (D2)”) that does not fall under the category of component (D1). Among these, the photodegradable base (component (D1)) is preferred because it is likely to enhance all of the properties of high sensitivity, reduced roughness, and suppressed coating defects. The components (D1) and (D2) may be contained in the form of a compound, or may be incorporated into the component (A1) as the aforementioned structural unit (a6), or may take both of these forms. The compounds exemplified below as the component (D1) may be used as the acid generator component (component (B)) in some cases in combination with other compounds.

[0357] 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 a compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"). The components (d1-1) to (d1-3) decompose and lose their acid diffusion controllability (basicity) in the exposed areas of the resist film, and therefore do not act as quenchers, but act as quenchers in the unexposed areas of the resist film.

[0358] [In the formula, Rd １ ~Rd ４ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the above, no fluorine atom is bonded to the carbon atom adjacent to the S atom. １ is a single bond or a divalent linking group; m is an integer of 1 or more; M ｍ＋ are each independently an m-valent organic cation.

[0359] {Component (d1-1)} Anion portion In formula (d1-1), Rd １ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of the R' ２０１ Among these, Rd １is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1) to (a2-r-7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the above formulas (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 in the formula (d1-1) has a linking group represented by each of the general formulae (L-al-1) to (L-al-8) as a substituent, in the general formulae (L-al-1) to (L-al-8), Rd in formula (d1-1) １ The carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the formula (L-al-1) to (L-al-8) 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.

[0360] 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.

[0361] Specific examples of preferred anion moieties of component (d1-1) are shown below.

[0362]

[0363] In the cation portion of 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.

[0364] {Component (d1-2)} Anion portion In formula (d1-2), Rd ２ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ However, Rd ２ In the formula, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not substituted with fluorine). This makes the anion of component (d1-2) an appropriately weak acid anion, improving the quenching ability of component (D). ２ The alkyl group is preferably a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent, and more preferably an aliphatic cyclic group which may have a substituent.

[0365] 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.

[0366] Rd ２ The hydrocarbon group may have a substituent, and the substituent may be Rd １ Examples of the substituents include the same as those that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0367] Specific examples of preferred anion moieties of component (d1-2) are shown below.

[0368]

[0369] In the cation portion of 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.

[0370] {Component (d1-3)} Anion portion In formula (d1-3), Rd ３ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ Among these, a fluorinated alkyl group is preferred, and the Rd １ The same fluorinated alkyl groups as those mentioned above are more preferred.

[0371] In formula (d1-3), Rd ４ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group, which may have a substituent, is preferable. ４ The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. ４ A part of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, etc. ４ The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0372] 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.

[0373] Rd ４ The cyclic group in ２０１ Examples thereof include cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclo[5.2.1.0], and the like. ２，６ ] An alicyclic group in which one or more hydrogen atoms have been removed from a cycloalkane such as decane or tetracyclododecane, or an aromatic group such as a phenyl group or naphthyl group is preferred. ４ When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in excellent lithography properties. ４ When is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency, and exhibits favorable sensitivity and lithography properties.

[0374] In formula (d1-3), 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. ２１ Examples of the divalent linking group include the same divalent hydrocarbon group which may have a substituent and the same divalent linking group containing a hetero atom as those mentioned in the description of the divalent linking group in 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.

[0375] Specific examples of preferred anion moieties of component (d1-3) are shown below.

[0376]

[0377]

[0378] In the cation portion of 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.

[0379] 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).

[0380] 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).

[0381] 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).

[0382] 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.

[0383] 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.

[0384] 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.

[0385] 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.

[0386] 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.

[0387] <At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxo acids, and derivatives thereof> The resist composition of this embodiment may contain at least one compound (E) (hereinafter referred to as "component (E)") selected from the group consisting of organic carboxylic acids, phosphorus oxo acids, and derivatives thereof as an optional component for the purposes of preventing sensitivity degradation and improving resist pattern shape and post-exposure stability. Specific examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, with salicylic acid being preferred. Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred.

[0388] 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.

[0389] <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 the 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 the component (F) include polymers having a structural unit (f1) represented by the following general formula (f1-1): This polymer is preferably a polymer (homopolymer) consisting 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.

[0390] [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, nf1 is an integer of 0 to 5, and Rf １０１ is an organic group containing a fluorine atom.

[0391] 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), nf1 is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0392] 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.

[0393] 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.

[0394] 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.

[0395] <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.

[0396] 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%.

[0397] 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.

[0398] The resist composition of this embodiment as described above contains a resin component (A1) that includes the structural unit (a0). By including the structural unit (a0), the resist composition of this embodiment exhibits the effects of improved sensitivity and reduced roughness and defects. The reason for this effect is presumed to be as follows: It is thought that the acid-dissociable group containing a quaternary carbon atom-quaternary carbon atom bond improves the ability to deprotect the protecting group with the acid generated by exposure. Furthermore, it is thought that the acid-dissociable group containing an alicyclic group that contains an oxygen atom improves the solubility of the exposed area in a developer. It is presumed that the effects of the above-mentioned actions acting synergistically result in improved sensitivity and reduced roughness and defects.

[0399] (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.

[0400] 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.

[0401] 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.

[0402] 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.

[0403] The wavelength used for exposure is not particularly limited, and may be an ArF excimer laser, a KrF excimer laser, or a F ２Radiation 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.

[0404] 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.

[0405] 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.

[0406] 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.

[0407] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0408] 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.

[0409] 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).

[0410] 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.

[0411] 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).

[0412] According to the method of forming a resist pattern of the present embodiment described above, the resist composition described above is used, so that a resist pattern can be formed with high sensitivity and reduced roughness and defects.

[0413] 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).

[0414] (Compound) The compound according to the third aspect of the present invention is a compound represented by the general formula (a0-m) (hereinafter, also referred to as "compound (M0)").

[0415] The compound (M0) is preferably a compound represented by the following general formula (m0-1) or (m0-2).

[0416] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ and R ０２ each independently represents a chain hydrocarbon group which may have a substituent, R ０１ and R ０２ may be bonded to each other to form a ring structure. ０３ represents a chain hydrocarbon group which may have a substituent. m0 and n0 each independently represent an integer of 0 to 4, and 2≦m0+n0≦8. Y ０１ represents a divalent linking group. k0 represents an integer of 0 to 2. ０ represents an aromatic hydrocarbon group which may have a substituent. ０２ represents a single bond or a divalent linking group. ０４ represents a substituent, and p0 represents an integer of 0 or more and 2(m0+n0) or less.

[0417] In the formulas (m0-1) and (m0-2), R, R ０１ , R ０２ , R ０３ , R ０４ , m0, n0, p0, Y ０１ , k0, Wa ０ , Y ０２ represents R and R in the formulas (a0-1) and (a0-2). ０１ , R ０２ , R ０３ , R ０４ , m0, n0, p0, Y ０１ , k0, Wa ０ , Y ０２ are the same as

[0418] Specific examples of the compound (MO) include, but are not limited to, the following: αrepresents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0419]

[0420]

[0421]

[0422]

[0423]

[0424]

[0425]

[0426]

[0427]

[0428]

[0429]

[0430]

[0431] <Method for Producing Compound> The compound (M0) can be produced by appropriately combining known methods, as in the <Synthesis Examples of Compounds> shown in the [Examples] below.

[0432] For example, the compound represented by the formula (m0-1) can be produced by the following reaction (I) or (II).

[0433] <Reaction (I)>

[0434] [In the formula, R, R ０１ , R ０２ , R ０３ , m0, n0, Y ０１ , k0, R ０４ , and p0 represents R, R in general formula (m0-1). ０１ , R ０２ , R ０３ , m0, n0, Y ０１ , k0, R ０４ , and p0, respectively.]

[0435] <Reaction (II)>

[0436] [In the formula, R, R ０１ , R ０２ , R ０３ , m0, n0, Y ０１ , k0, R ０４ , and p0 represents R, R in general formula (m0-1). ０１ , R ０２ , R ０３ , m0, n0, Y ０１ , k0, R ０４ , and p0, respectively.]

[0437] Examples of reaction solvents used in reactions (I) and (II) include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, and dimethyl sulfoxide.

[0438] In the reactions (I) and (II), a basic catalyst may be used. Examples of the basic catalyst include tertiary amines such as trimethylamine, triethylamine, and tributylamine, aromatic amines such as pyridine, dimethylaminopyridine (DMAP), and pyrrolidinopyridine, diazabicyclononene (DBN), and diazabicycloundecene (DBU).

[0439] The temperature conditions for the reactions (I) and (II) are, for example, 0 to 50° C. The reaction times for the reactions (I) and (II) are, for example, 10 minutes to 24 hours.

[0440] For example, the compound represented by the formula (m0-2) can be produced by the following reaction (III).

[0441] <Reaction (III)>

[0442] [In the formula, R, R ０１ , R ０２ , R ０３ , m0, n0, Wa ０ , Y ０２ , R ０４ , and p0 represents R, R in general formula (m0-2). ０１, R ０２ , R ０３ , m0, n0, Wa ０ , Y ０２ , R ０４ , and p0, respectively.]

[0443] In the reaction (III), a condensation reaction is carried out in the presence of a condensing agent and a basic catalyst.

[0444] Examples of the reaction solvent used in the reaction (III) include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, and dimethyl sulfoxide.

[0445] Examples of the basic catalyst used in reaction (III) include tertiary amines such as trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine, dimethylaminopyridine (DMAP), and pyrrolidinopyridine; diazabicyclononene (DBN); and diazabicycloundecene (DBU).

[0446] Examples of the condensing agent used in the reaction (III) include N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide (DIC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and carbonyldiimidazole (CDI).

[0447] The temperature condition for the reaction (III) is, for example, 0 to 50° C. The reaction time for the reaction (III) is, for example, 10 minutes to 24 hours.

[0448] The alcohol (AL-0-1) may be commercially available or may be produced by a known method. The alcohol (AL-0-1) can be produced, for example, by the following reaction (IV) or (V).

[0449] <Reaction (IV)>

[0450] [In the formula, R ０３ , m0, n0, R ０４ , and p0 is R in the general formula (m0-1).０３ , m0, n0, R ０４ , and p0, respectively. ０１’ and R ０２’ each independently represents a chain hydrocarbon group which may have a substituent.

[0451] <Reaction (V)>

[0452] [In the formula, R ０３ , m0, n0, R ０４ , and p0 is R in the general formula (m0-1). ０３ , m0, n0, R ０４ , and p0, respectively. q0 represents an integer of 1 or more.]

[0453] Examples of reaction solvents used in reactions (IV) and (V) include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, and dimethyl sulfoxide.

[0454] The temperature conditions for the reactions (IV) and (V) are, for example, 0 to 50° C. The reaction times for the reactions (IV) and (V) are, for example, 10 minutes to 24 hours.

[0455] The alcohol (AL-0-2) may be commercially available or may be produced by a known method. The alcohol (AL-0-1) having an adamantyl group can be produced, for example, by the following reaction (VI).

[0456] <Reaction (VI)>

[0457] [In the formula, R, R ０１ , R ０２ , R ０３ , m0, n0, Y ０１ , k0, R ０４ , and p0 represents R, R in general formula (m0-1). ０１ , R ０２ , R ０３ , m0, n0, Y ０１ , k0, R ０４ , and p0, respectively.]

[0458] In reaction (VI), examples of the reaction solvent used in the reaction of producing compound (MAL-0) from compound (AHD-01) and alcohol (AL-0-1) include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, and dimethyl sulfoxide.

[0459] In reaction (VI), examples of the basic catalyst used in the reaction for producing compound (MAL-0) from compound (AHD-01) and alcohol (AL-0-1) include tertiary amines such as lithium diisopropylamide (LDA), trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine, dimethylaminopyridine (DMAP), and pyrrolidinopyridine; diazabicyclononene (DBN); and diazabicycloundecene (DBU).

[0460] In reaction (VI), the temperature condition for producing compound (MAL-0) from compound (AHD-01) and alcohol (AL-0-1) is, for example, 0 to 50°C. In reaction (VI), the reaction time for producing compound (MAL-0) from compound (AHD-01) and alcohol (AL-0-1) is, for example, 10 minutes to 24 hours.

[0461] In reaction (VI), the reaction of producing the alcohol (AL-0-3) from compound (MAL-0) can be carried out in the presence of sodium bicarbonate and a persulfate compound using a mixed solvent of ethyl acetate and acetone. The temperature condition can be, for example, 0 to 50°C, and the reaction time can be, for example, 10 minutes to 24 hours.

[0462] In the above-described method for producing compound (M0), after each reaction is completed, the compound in the reaction solution may be isolated and purified. Conventionally known methods can be used for isolation and purification, and for example, an appropriate combination of concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used. The structure of the compound obtained as described above can be identified by general organic analysis methods such as liquid chromatography mass spectrometry (LC-MS), 1H-nuclear magnetic resonance (NMR) spectroscopy, and 13C-NMR spectroscopy. Commercially available raw materials or synthesized raw materials may be used in each step.

[0463] The compound of this embodiment described above can be used to produce a resist composition according to the first aspect, and can also be used to produce a polymer compound according to the fourth aspect described below.

[0464] (Polymer Compound) A polymer compound according to the fourth aspect of the present invention has a structural unit (a0) derived from a compound represented by the general formula (a0-m). The structural unit (a0) is the same as described above. The polymer compound of this embodiment can be used to produce a resist composition according to the first aspect. By incorporating the polymer compound of this embodiment into a resist composition, it is possible to obtain a resist composition that has high sensitivity and exhibits reduced roughness and defects.

[0465] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0466] <Synthesis Examples of Compounds> (Synthesis Example of Compound (M0-1)) <Synthesis of Alcohol (AL-01)> Compound (KE-01) (8.0 g, 70.0 mmol) was dissolved in 25 g of tetrahydrofuran (THF), and after cooling to 5°C, 90 mL of a 1 mol / L THF solution of methylmagnesium bromide was added dropwise over 30 minutes, and the mixture was allowed to react for 1 hour. After stirring at room temperature for 2 hours, the mixture was cooled to 5°C, and 100 g of a 10% aqueous acetic acid solution was added dropwise over 1 hour. Thereafter, 100 g of TBME was added, and the mixture was stirred for 30 minutes. The collected organic layer was washed three times with 100 g of ultrapure water. After removing the solvent, the mixture was purified by column chromatography to obtain alcohol (AL-01) (6.8 g, yield=75.0%).

[0467]

[0468] Synthesis of Compound (M0-1) Alcohol (AL-01) (6.5 g, 50.0 mmol), triethylamine (7.6 g, 75.0 mmol), and acetonitrile (120 g) were mixed and cooled to 5°C. Then, a solution of methacrylic acid chloride (7.9 g, 75.0 mmol) in acetonitrile (120 g) was added dropwise over 30 minutes, and the mixture was allowed to react for 1 hour. Then, 1% NH ３ An aqueous solution (150 g) and dichloromethane (150 g) were added and stirred for 30 minutes. The organic layer was recovered and washed three times with 100 g of ultrapure water. After removing the solvent, the mixture was purified by column chromatography to obtain compound (M0-1) (8.2 g, yield=83.0%).

[0469]

[0470] (Synthesis Example of Compounds (M0-2) to (M0-9)) <Synthesis of Alcohol (AL-02)> Compound (ES-01) (20.8 g, 160.0 mmol) was dissolved in 60 g of THF and cooled to 5°C. Thereafter, 200 mL of a 1 mol / L THF solution of Di Grignard reagent prepared in advance was added dropwise over 30 minutes, and the mixture was allowed to react for 1 hour. After stirring at room temperature for 2 hours, the mixture was cooled to 5°C. Thereafter, 300 g of a 10% aqueous acetic acid solution was added dropwise over 1 hour. Thereafter, 300 g of TBME was added, and the mixture was stirred for 30 minutes. The recovered organic layer was washed three times with 250 g of ultrapure water. After removing the solvent, the mixture was purified by column chromatography to obtain alcohol (AL-02) (12.5 g, yield=55.0%).

[0471]

[0472] <<Synthesis of Alcohol Derivatives (AL-03) to (AL-09)>> Alcohol Derivatives (AL-03) to (AL-09) were obtained by the same method as in the above-mentioned Synthesis Example of <<Synthesis Example of Alcohol Derivative (AL-02)>>, except that the ester of compound (ES-01) and the type of Di Grignard reagent were changed.

[0473]

[0474] In the synthesis of alcohol compounds (AL-03) to (AL-09), m, n, and q are as follows: Alcohol compound (AL-03): m = 1, n = 1, q = 2 Alcohol compound (AL-04): m = 1, n = 1, q = 3 Alcohol compound (AL-05): m = 1, n = 2, q = 1 Alcohol compound (AL-06): m = 0, n = 3, q ​​= 2 Alcohol compound (AL-07): m = 1, n = 2, q = 2 Alcohol compound (AL-08): m = 1, n = 2, q = 3 Alcohol compound (AL-09): m = 3, n = 1, q = 2

[0475]

[0476] <<Synthesis of Compounds (M0-2) to (M0-9)>> Compounds (M0-2) to (M0-9) were obtained by the same method as in <<Synthesis of Compound (M0-1)>> above, except that alcohols (AL-03) to (AL-09) were used instead of alcohol (AL-01), respectively.

[0477]

[0478] (Synthesis Example of Compounds (M0-10) to (M0-11)) <Synthesis of Intermediate (MAL-10)> A solution of alcohol (AL-02) (11.3 g, 80 mmol) in THF (50 g) was added dropwise to lithium diisopropylamide (LDA) (1.08 mol / L in n-hexane / THF (70 / 30 wt %) solution, 53 g, 80 mmol) over 1.5 hours at an internal temperature of 0 to 5°C. After stirring for 25 minutes at or below 5°C, a solution of compound (AHD-01) (12.3 g, 75 mmol) in THF (100 g) was added dropwise over 1 hour at an internal temperature of 5°C or below. Stirring was continued for 16 hours at an internal temperature of 5°C or below. Thereafter, 150 g of pure water was added dropwise over 30 minutes. To the resulting mixture, 200 g of tert-butyl methyl ether (TBME) was added, and the mixture was stirred at room temperature for 30 minutes. Then, 150 g of TBME was added to the collected aqueous layer, and the aqueous layer was washed. After repeating the same washing operation twice, the collected aqueous layer was washed with CH ２ Cl ２ The organic layer was washed three times with 200 g of ultrapure water, and after removing the solvent, intermediate (MAL-10) was obtained (16.1 g, yield: 75.0%).

[0479]

[0480] <<Synthesis of Intermediates (MAL-11) to (MAL-13)>> Intermediates (MAL-11), (MAL-12), and (MAL-13) were obtained in the same manner as in <<Synthesis of Intermediate (MAL-10)>> above, except that the alcohol (AL-02) was replaced with equimolar alcohols (AL-03), (AL-07), and (AL-08), respectively.

[0481]

[0482] <Synthesis of Alcohol (AL-10)> Intermediate (MAL-10) (16.8 g, 55 mmol), 150 g of ethyl acetate, and 60 g of acetone were mixed, and then an 8% aqueous sodium bicarbonate solution (185 g, NaHCO ３ 176 mmol) was added. Then, 20% Oxone® aqueous solution (135 g, KHSO ５ A solution of 1800kJ / ml of sodium sulfite (5.88 mmol) was added dropwise at room temperature over 20 minutes. The reaction solution was stirred at room temperature for 2.5 hours, sodium sulfite (5.9 g, 47 mmol) was added, and the mixture was stirred at room temperature for 30 minutes. Thereafter, the organic layer was separated by a separation operation, and then 150 g of ethyl acetate was added to the collected aqueous layer. After stirring at room temperature for 15 minutes, the organic layer was separated. The separated organic layers were combined, and then 100 g of ultrapure water was added thereto, and the organic layer was washed three times. The obtained organic phase was concentrated, and 700 g of n-heptane was added dropwise at room temperature over 40 minutes. After stirring for 1 hour, the obtained slurry was subjected to suction filtration to obtain a filtrate. The collected filtrate was dried under reduced pressure to obtain an alcohol form (AL-10) (15.5 g, yield = 87.5%).

[0483]

[0484] <<Synthesis of Alcohols (AL-11) to (AL-13)>> Alcohols (AL-11), (AL-12), and (AL-13) were obtained in the same manner as in <<Synthesis of Alcohol (AL-10)>> above, except that the alcohol (AL-10) was replaced with equimolar intermediates (MAL-11), (MAL-12), and (MAL-13), respectively.

[0485]

[0486] <<Synthesis of Compounds (M0-10) to (M0-13)>> Compounds (M0-10) to (M0-13) were obtained by the same method as in <<Synthesis of Compound (M0-1)>> above, except that alcohols (AL-10) to (AL-13) were used instead of alcohol (AL-01), respectively.

[0487]

[0488] (Synthesis Example of Compound (M0-14)) Alcohol (AL-07) (8.5 g, 50.0 mmol), 4-vinylsalicylic acid (7.4 g, 50.0 mmol), and dimethylaminopyridine (DMAP) (0.8 g, 6.4 mmol) were dissolved in 150 g of dichloromethane, and diisopropylcarbodiimide (DIC) (7.6 g, 60 mmol) was added to the solution. After stirring at room temperature for 16 hours, insoluble matter was removed by filtration. The solvent in the recovered organic layer was distilled off, and the resulting concentrate was dissolved in 20 g of methanol and 20 g of acetonitrile. 200 g of TBME was added dropwise to the solution over 30 minutes. The precipitate was recovered by filtration and dried under reduced pressure to obtain compound (M0-14) (12.3 g, yield=82.0%).

[0489]

[0490] (Synthesis Example of Compounds (M0-15) to (M0-20)) Compounds (M0-15) to (M0-20) were obtained in the same manner as in the above (Synthesis Example of Compound (M0-14)), except that the alcohol (AL-07) was changed to equimolar alcohols (AL-09) and (AL-12), respectively, and 4-vinylbenzoic acid was changed to carboxylic acids (CA-2) to (CA-5), respectively.

[0491]

[0492]

[0493] The structures of compounds (M0-1) to (M0-20) obtained in the above synthesis examples were confirmed by measuring the molecular ion peak using an LC / MS device (Waters ACQUITY UPLC H-Class / SQD system). The results are shown in Table 1.

[0494]

[0495] <Production of Polymer Compound> (Synthesis of Polymer Compound (A1-1)) Compound (M0-1) (11.9 g), compound (M10-pre) (11.5 g), and azobis(isobutyrate) dimethyl (V-601, 2.8 g) as a polymerization initiator were dissolved in methyl ethyl ketone (MEK) (62.9 g) and cyclohexanone (15.7 g) to prepare a dropping solution. MEK (9.1 g) was added to a three-neck flask equipped with a thermometer, a reflux condenser, and a nitrogen inlet tube, and the mixture was heated to 80°C under a nitrogen atmosphere, and the dropping solution was added dropwise over 4 hours. After completion of the dropwise addition, the reaction solution was stirred at 80°C for 1 hour. The reaction solution was then cooled to room temperature. After completion of the reaction, propylene glycol monomethyl ether (150 g) and trifluoroacetic acid (20.5 g) were added to the resulting reaction solution, and the mixture was stirred at room temperature under a nitrogen atmosphere for 16 hours. After the reaction was completed, the resulting reaction solution was precipitated with heptane (400 g) and the precipitate was washed. The resulting white solid was filtered and dried under reduced pressure overnight to obtain a polymer compound (A1-1).

[0496]

[0497] (Synthesis of Polymer Compounds (A1-2) to (A1-29)) Polymer compounds (A1-2) to (A1-29) were each synthesized in the same manner as in the synthesis of polymer compound (A1-1), except that the compounds used in the polymerization reaction were changed.

[0498] The polymeric compounds (A1-1) to (A1-29) are shown below: In the following formulae, l, m, and n represent the composition ratio (molar ratio) of each structural unit.

[0499]

[0500]

[0501]

[0502]

[0503]

[0504]

[0505] (Synthesis of Comparative Polymer Compounds (A2-1) to (A2-6)) Polymer compounds (A2-1) to (A2-6) were each synthesized in the same manner as in the synthesis of polymer compound (A1-1), except that the compounds used in the polymerization reaction were changed.

[0506] The polymeric compounds (A2-1) to (A2-6) are shown below: In the following formulas, l, m, and n represent the composition ratio (molar ratio) of each structural unit.

[0507]

[0508] The weight average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) of each of the resulting polymer compounds (A1-1) to (A1-29) and (A2-1) to (A2-6) were determined by GPC measurement (standard polystyrene equivalent). Furthermore, the copolymer composition ratios (proportions (molar ratios) of each structural unit in the structural formula) of each of the polymer compounds (A1-1) to (A1-29) and (A2-1) to (A2-6) were determined by carbon-13 nuclear magnetic resonance spectroscopy (600 MHz, １３ The results are shown in Tables 2 and 3.

[0509]

[0510]

[0511] <Preparation of Resist Compositions> (Examples 1 to 29, Comparative Examples 1 to 6) The components shown in Tables 4 to 6 were mixed and dissolved to prepare the resist compositions of each example.

[0512]

[0513]

[0514]

[0515] In Tables 4 to 6, the abbreviations have the following meanings. The numbers in brackets [ ] indicate the blend amounts (parts by mass). (A1)-1 to (A1)-29: the above polymeric compounds (A1-1) to (A1-29). (A2)-1 to (A2)-6: the above polymeric compounds (A2-1) to (A2-6).

[0516] (B1)-1: An acid generator comprising the following compound (B1-1).

[0517]

[0518] (D1)-1: An acid diffusion controller consisting of a compound represented by the following chemical formula (D1-1).

[0519]

[0520] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether=60 / 40 (mass ratio).

[0521] <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.

[0522] Step of exposing resist film: Next, the resist film was subjected to drawing (exposure) using an electron beam lithography system JEOL-JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100 kV to form a 1:1 line and space pattern (hereinafter referred to as "LS pattern") with a target size of a line width of 25 nm (pitch width of 50 nm). Thereafter, a post-exposure bake (PEB) treatment was performed at 110°C for 60 seconds.

[0523] 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 25 nm was formed.

[0524] [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 Tables 6 to 8.

[0525] [Evaluation of LWR (Line Width Roughness)] For the LS patterns formed in the above <Formation of Resist Pattern>, 3σ, a measure of LWR, was determined. This is shown in Tables 6 to 8 as "LWR (nm)." "3σ" represents three times the standard deviation (σ) (unit: nm) obtained from the measurement results of 400 line positions measured in the longitudinal direction of the line using a scanning electron microscope (acceleration voltage 800 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the smaller the roughness of the line sidewalls, meaning that an LS pattern with a more uniform width was obtained.

[0526] [Defect Evaluation] For the LS pattern formed in the above <Formation of Resist Pattern>, the total number of defects in the wafer (total number of defects) was measured using a surface defect observation device (product name: KLA2905, manufactured by KLA-Tencor Corporation). The target defects were limited to those 1 μm or larger in size, and measurements were performed 10 times per sample. The average evaluation result was taken as the "number of defects." A relative value was calculated when the number of foreign matter / defects on the coating film surface of Comparative Example 1 was set to 1.0. This is shown in Tables 7 to 9 as "defects."

[0527]

[0528]

[0529]

[0530] As shown in Tables 7 to 9, it was confirmed that the resist compositions of Examples 1 to 29 were superior to the resist compositions of Comparative Examples 1 to 6 in terms of sensitivity, LWR, and defects.

[0531] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible within the scope of the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

Claims

A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, a resin component (A1) whose solubility in a developer changes under the action of an acid, The resin component (a1) has a structural unit (a0) derived from a compound represented by the following general formula (a0-m): Resist composition. [In the formula, W ０ represents a polymerizable group-containing group. ０１ and R ０２ each independently represents a chain hydrocarbon group which may have a substituent, R ０１ and R ０２ may be bonded to each other to form a ring structure. ０３ represents a chain hydrocarbon group which may have a substituent. m0 and n0 each independently represent an integer of 0 to 4, and 2≦m0+n0≦8. R ０４ represents a substituent, and p0 represents an integer of 0 or more and 2(m0+n0) or less. R in the general formula (a0-m) ０１ and R ０２ The resist composition according to claim 1 , wherein: are bonded to each other to form a ring structure.

3. The resist composition according to claim 1, wherein the structural unit (a0) is a structural unit represented by the following general formula (a0-1) or (a0-2): [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ and R ０２ each independently represents a chain hydrocarbon group which may have a substituent, R ０１ and R ０２ may be bonded to each other to form a ring structure. ０３ represents a chain hydrocarbon group which may have a substituent. m0 and n0 each independently represent an integer of 0 to 4, and 2≦m0+n0≦8. Y ０１ represents a divalent linking group. k0 represents an integer of 0 to 2. ０ represents an aromatic hydrocarbon group which may have a substituent. ０２ represents a single bond or a divalent linking group. ０４ represents a substituent, and p0 represents an integer of 0 or more and 2(m0+n0) or less.

3. A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using the resist composition according to claim 1; exposing the resist film; and developing the exposed resist film to form a resist pattern. 　 A compound represented by the following general formula (a0-m): [In the formula, W ０ represents a polymerizable group-containing group. ０１ and R ０２ each independently represents a chain hydrocarbon group which may have a substituent, R ０１ and R ０２ may be bonded to each other to form a ring structure. ０３ represents a chain hydrocarbon group which may have a substituent. m0 and n0 each independently represent an integer of 0 to 4, and 2≦m0+n0≦8. R ０４ represents a substituent, and p0 represents an integer of 0 or more and 2(m0+n0) or less. R in the general formula (a0-m) ０１ and R ０２ The compound according to claim 5 , wherein are bonded to each other to form a ring structure. 　 The compound according to claim 5 or 6, which is a compound represented by the following general formula (m0-1) or (m0-2): [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ and R ０２ each independently represents a chain hydrocarbon group which may have a substituent, R ０１ and R ０２ may be bonded to each other to form a ring structure. ０３ represents a chain hydrocarbon group which may have a substituent. m0 and n0 each independently represent an integer of 0 to 4, and 2≦m0+n0≦8. Y ０１ represents a divalent linking group. k0 represents an integer of 0 to 2. ０ represents an aromatic hydrocarbon group which may have a substituent. ０２ represents a single bond or a divalent linking group. ０４ represents a substituent, and p0 represents an integer of 0 or more and 2(m0+n0) or less. 　 A polymer compound having a structural unit derived from the compound according to claim 5 or 6.

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