Resist composition and method for forming resist pattern

Abstract

To provide a resist composition capable of forming a resist pattern that contains an acid generator in which a carbon atom adjacent to a sulfonic acid is not fluorinated, maintains good sensitivity, exhibits favorable lithography characteristics such as roughness, and achieves reduced pattern defects.SOLUTION: A resist composition containing a resin component (A1), a compound (B0) represented by general formula (b0), and a fluororesin component (F1) having a structural unit (f1) containing a base-dissociable group of a specific structure, wherein, in the formula, Ar represents an aromatic ring, Rf0 represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom, L0 represents a divalent linking group containing -C(=O)-O-, -O-C(=O)-, or -O-S(=O)2-, Yb0 represents a cyclic group, Rb0 represents an organic group, n01 is an integer of 1 or more as permitted by valency, and n02 is an integer of 0 or more as permitted by valency.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resist composition and a method of forming a resist pattern. [Background technology]

[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 and resolution capable of reproducing patterns with minute dimensions. To satisfy these requirements, a chemically amplified resist composition has been used, which contains a base component whose solubility in a developer changes due to the action of acid, and an acid generator component that generates acid upon exposure.

[0004] In chemically amplified resists, acid generators in which the proximal carbon of the sulfonic acid group is perfluorinated have been put to practical use as acid generators that provide an acid with sufficient acid strength for deprotection. Meanwhile, in response to growing environmental awareness in recent years, low-fluorinated sulfonates with reduced fluorine content have been proposed for the purpose of reducing environmental impact. However, even with low-fluorinated acid generators, it is necessary to introduce a fluorine atom into the proximal carbon of the sulfonic acid group in order to ensure acid strength. For example, Patent Document 1 describes an acid generator in which the carbon atom adjacent to the sulfonic acid group is fluorinated. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-92159 Summary of the Invention [Problem to be solved by the invention]

[0006] With the further increase in environmental awareness in the future, there is a possibility that the production and use of acid generators in which a fluorine atom has been introduced into the carbon atom adjacent to the sulfonic acid group will be restricted. However, with conventional acid generators such as the acid generator described in Patent Document 1, it is difficult to obtain sufficient acid strength if the carbon atom adjacent to the sulfonic acid group is not fluorinated. Meanwhile, further advances in lithography technology are rapidly leading to finer patterns, and therefore there is a demand for resist compositions that can form resist patterns that have good lithography properties such as roughness and reduced pattern defects while maintaining good sensitivity.

[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 contains an acid generator in which the adjacent carbon atom of the sulfonic acid is not fluorinated, and that is capable of forming a resist pattern that exhibits excellent lithography properties such as roughness and has reduced pattern defects while maintaining good sensitivity, and a method of forming a resist pattern that uses the resist composition. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration. Specifically, a first aspect of the present invention is a resist composition that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid. The resist composition comprises a resin component (A1) whose solubility in a developer changes due to the action of the acid, an acid generator component (B) that generates an acid upon exposure, and a fluororesin component (F1) that has a structural unit (f1) that contains a base dissociable group, wherein the acid generator component (B) contains a compound (B0) represented by the following general formula (b0), and the structural unit (f1) that contains a base dissociable group contains at least one structural unit selected from the group consisting of a structural unit (f1-1) represented by the following general formula (f1-2), a structural unit (f1-2) represented by the following general formula (f1-3), and a structural unit (f1-3) represented by the following general formula (f1-3).

[0009] [ka] [In the formula, Ar represents an aromatic ring. Rf 0 represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 0 represents a divalent linking group containing -C(=O)-O-, -OC(=O)- or -OS(=O)2-. 0 represents a cyclic group. 0 represents an organic group. n01 is an integer of 1 or more as long as the valence allows. n02 is an integer of 0 or more as long as the valence allows. However, L 0 -Yb 0 -OC(=O)-Yb 0 If Yb 0 is an alicyclic group which may have a substituent, a fused cyclic group of an aliphatic ring and an aromatic ring which may have a substituent, or an aromatic hydrocarbon group which has a substituent, and in the aromatic hydrocarbon group, at least one hydrogen atom of the aromatic ring is substituted with an alkyl group or an alkoxy group. 0 may be the same or different. When n02 is 2 or more, multiple Rb 0 may be the same or different, m is an integer of 1 or more, and M m+ represents an m-valent cation, where Rf 0 , L 0 , Yb 0 , Rb 0 and M m+ is the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 - does not include the structure represented by Rpf 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0010] [ka] [wherein each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Lf 1 and Lf 2 are each independently a divalent linking group not containing an acid-labile group; Rf 1 and Rf 3 are each independently an organic group having a fluorine atom; Rf 2 is a monovalent organic group, provided that Lf 2 and Rf 2 at least one of A is a group in which some or all of the hydrogen atoms are substituted with fluorine atoms; aryl is a divalent aromatic hydrocarbon group which may have a substituent; Lf 3 is a divalent linking group that does not have a single bond or a polycyclic structure and does not contain an acid-dissociable group.

[0011] 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 according to the first aspect, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a resist composition that contains an acid generator in which the adjacent carbon atom of the sulfonic acid is not fluorinated, and that is capable of forming a resist pattern that exhibits excellent lithography properties such as roughness and has reduced pattern defects while maintaining good sensitivity, as well as a method of forming a resist pattern that uses the resist composition. DETAILED DESCRIPTION OF THE INVENTION

[0013] In this specification and claims, the term "aliphatic" is defined as a relative concept to aromatic, and refers to groups, compounds, etc. that do not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, the term "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups. The "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). The phrase "may have a substituent" includes both the case where a hydrogen atom (-H) is replaced with a monovalent group and the case where a methylene group (-CH2-) is replaced with a divalent group. The term "exposure" is a general concept that includes irradiation with radiation.

[0014] The term "acid-decomposable group" refers to a group having acid decomposability in which at least some of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that decompose under the action of an acid to generate a polar group. Examples of polar groups include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO3H). More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0015] The term "acid-dissociable group" refers to either (i) a group having acid dissociability such that the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group in which a portion of the bond is cleaved by the action of an acid, and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group. The acid-dissociable group constituting the acid-decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid-dissociable group. Therefore, when the acid-dissociable group dissociates due to the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, increasing the polarity. As a result, the polarity of the 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.

[0016] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly divided into non-polymers and polymers. Non-polymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, the term "low molecular weight compound" refers to a non-polymer with a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, the terms "resin," "high molecular weight compound," or "polymer" refer to a polymer with a molecular weight of 1000 or more. The molecular weight of a polymer is determined by the weight average molecular weight converted into polystyrene by GPC (gel permeation chromatography).

[0017] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, such as an ethylenic double bond. In the "acrylate ester," the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. 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 hydroxyl group is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group. Unless otherwise specified, the α-carbon atom of an acrylic ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylic ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylic ester.

[0018] The term "derivative" encompasses compounds in which the hydrogen atom at the α-position of the target compound is substituted with another substituent, such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include compounds in which the hydrogen atom of a hydroxyl group of a target compound, which may have the hydrogen atom at the α-position substituted with a substituent, is substituted with an organic group; and compounds in which a substituent other than a hydroxyl group is bonded to a target compound, which may have the hydrogen atom at the α-position substituted with a substituent. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. The substituents that replace the hydrogen atom at the α-position of hydroxystyrene include R αx The same can be mentioned.

[0019] In this specification and claims, some structures represented by chemical formulas may have asymmetric carbon atoms, and may exist as enantiomers or diastereomers. In such cases, a single chemical formula represents all isomers. These isomers may be used alone or as a mixture.

[0020] (Resist composition) The resist composition of this embodiment generates an acid upon exposure, and the solubility in a developer changes due to the action of the acid. The resist composition contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes under the action of acid, an acid generator component (B) (hereinafter also referred to as "component (B)") that generates acid upon exposure, and a fluororesin component (F1) (hereinafter also referred to as "component (F1)") having a structural unit (f1) that contains a base-dissociable group. The component (B) contains a compound (B0) (hereinafter also referred to as "component (B0)") represented by general formula (b0) described below. Furthermore, the resist composition of this embodiment may further contain other components in addition to the above-mentioned components (A), (B0), and (F1). Examples of other components include the following components (B), (D1), (D2), (E), and (S).

[0021] Specifically, the resist composition of this embodiment contains (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 may also contain component (B). That is, in the cases of (2) and (3) above, the component (A) is a "base component that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid." When the component (A) is a base component that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, the component (A1) described below is preferably a resin that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid. Such a resin can be a polymeric compound having a structural unit that generates acid upon exposure. The structural unit that generates acid upon exposure can be, for example, the structural unit (a5) described below.

[0022] When a resist film is formed using the resist composition of this embodiment and then subjected to selective exposure, an acid is generated from, for example, component (A) and / or component (B) in the exposed areas of the resist film, and the solubility of component (A) in a developer changes due to the action of the acid, whereas the solubility of 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.

[0023] The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Furthermore, the resist composition of this embodiment may be for an alkaline development process in which an alkaline developer is used in the development treatment during resist pattern formation, or may be for a solvent development process in which a developer containing an organic solvent (organic developer) is used in the development treatment.

[0024] <Base material component (A)> In the resist composition of this embodiment, the component (A) contains a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes under the action of 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 alkaline development processes but also in solvent development processes. As the component (A), other polymeric compounds and / or low molecular weight compounds may be used in combination with the component (A1).

[0025] In the resist composition of this embodiment, the component (A) may use either a single type of compound, or a combination of two or more types of compounds.

[0026] About component (A1) The component (A1) is a resin component whose solubility in a developer changes under the action of an acid. The component (A1) preferably has a structural unit (a1) that includes an acid-decomposable group whose polarity increases upon the action of an acid. The component (A1) may contain other structural units in addition to the structural unit (a1), as necessary.

[0027] <Constituent unit (a1)> The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases upon the action of an acid.

[0028] Examples of the acid-dissociable group include those that have been proposed as acid-dissociable groups for base resins used in chemically amplified resist compositions. Specific examples of acid-dissociable groups that have been proposed for use in base resins for chemically amplified resist compositions include the "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," "tertiary alkyloxycarbonyl acid-dissociable groups," and "secondary alkyloxycarbonyl acid-dissociable groups," which are explained below.

[0029] 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 groups").

[0030] [ka] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.]

[0031] In formula (a1-r-1), Ra' 1 and Ra' 2 At least one of these is preferably a hydrogen atom, and both are more preferably hydrogen atoms. Ra' 1 or Ra' 2 When is an alkyl group, examples of the alkyl group include the same alkyl groups as those exemplified as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester above, and an alkyl group having 1 to 5 carbon atoms is preferred. Specific examples include linear or branched alkyl groups. More specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups, with methyl and ethyl groups being more preferred, and methyl being particularly preferred.

[0032] 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.

[0033] 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.

[0034] Ra' 3 When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] 2,6 ]decane, tetracyclododecane, and the like.

[0035] Ra' 3 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings. Ra' 3 Specific examples of the aromatic hydrocarbon group in the formula (I) include a group (aryl group or heteroaryl group) in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle; a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0036] Ra' 3 The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (hereinafter these substituents are collectively referred to as "Rax5 ") are also examples. where R P1 is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R P2 Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group, and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents, or may have one or more of each of multiple types of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, and cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl group, tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and adamantyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0037] Ra' 3 But Ra' 1 , Ra' 2When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0038] Tertiary alkyl ester-type acid-labile group: Among the polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group may be referred to as "tertiary alkyl ester-type acid-dissociable groups" hereinafter for convenience.

[0039] [ka] [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.

[0040] Ra' 4 Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. Ra' 4 The linear or branched alkyl group and the cyclic hydrocarbon group (the monocyclic aliphatic hydrocarbon group, the polycyclic aliphatic hydrocarbon group, and the aromatic hydrocarbon group) in 3 The same can be mentioned. Ra' 4 The chain or cyclic alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 The hydrocarbon group of Ra' 3 The same can be mentioned.

[0041] Ra' 5 and Ra'6 and (a1-r2-3) are preferably substituted or unsubstituted by the alkyl group. On the other hand, Ra' 4 ~Ra' 6 When are not bonded to each other and are independent hydrocarbon groups, preferred examples include groups represented by the following general formula (a1-r2-4).

[0042] [ka] [In formula (a1-r2-1), Ra' 10 Ra' 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 Ra' 10 represents a group that forms an aliphatic cyclic group together with the carbon atom to which Ya is bonded. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra 101 ~Ra 103 are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. 101 ~Ra 103 Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group which forms an aliphatic cyclic group together with Yaa. Ra 104 In formula (a1-r2-4), Ra' is an aromatic hydrocarbon group which may have a substituent. 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14is a hydrocarbon group which may have a substituent. * indicates a bond (the same applies hereinafter).

[0043] 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.

[0044] Ra' 10 The linear alkyl group in the formula (I) has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra' 10 In the formula (I), the branched alkyl group is the above-mentioned Ra' 3 The same can be mentioned.

[0045] Ra' 10 The alkyl group in may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Furthermore, some of the carbon atoms (e.g., methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. Examples of heteroatoms include oxygen, sulfur, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0046] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed together with the carbon atom to which the carbon atom is bonded is represented by Ra' in formula (a1-r-1). 3 Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl and cyclohexyl groups are more preferred.

[0047] 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 such groups include groups in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) shown above. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. The substituent may be any of the above-mentioned Ra' 3 Examples of the substituents include the same as those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 101 ~Ra 103 In the formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Ra 101 ~Ra 103 In the formula (I), examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a 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 ] Examples thereof include polycyclic aliphatic saturated hydrocarbon groups such as a dodecanyl group and an adamantyl group. Ra 101 ~Ra 103 Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferred, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferred, with a hydrogen atom being particularly preferred.

[0048] 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: x5 The same groups as those shown below can be mentioned.

[0049] Ra 101 ~Ra 103 Examples of the group containing a carbon-carbon double bond formed by two or more of the above being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidene-ethenyl group, a cyclohexylidene-ethenyl group, etc. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0050] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). 3 The groups mentioned above as the aliphatic hydrocarbon group are preferably monocyclic or polycyclic groups. In formula (a1-r2-3), Ra 104 Examples of the aromatic hydrocarbon group in the formula include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. 104 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0051] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed by include a methyl group, an ethyl group, a propyl group, a hydroxy group, a carboxy group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), and an alkyloxycarbonyl group.

[0052] In formula (a1-r2-4), Ra' 12 and Ra' 13are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. 12 and Ra' 13 In the formula, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned Ra 101 ~Ra 103 Examples include the same monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms as in the above. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, alkyl groups having 1 to 5 carbon atoms are preferred, alkyl groups having 1 to 5 carbon atoms are more preferred, methyl groups and ethyl groups are even more preferred, and methyl groups are particularly preferred. The above Ra' 12 and Ra' 13 When the chain saturated hydrocarbon group represented by the formula: is substituted, examples of the substituent include the above-mentioned Ra x5 The same groups as those shown below can be mentioned.

[0053] In formula (a1-r2-4), Ra' 14 Ra' is a hydrocarbon group which may have a substituent. 14 The hydrocarbon group in the formula (I) includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0054] Ra' 14 The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0055] Ra' 14The branched alkyl group in the formula (I) preferably has 3 to 10 carbon atoms, more preferably 3 to 5. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0056] Ra' 14 When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] 2,6 ]decane, tetracyclododecane, and the like.

[0057] Ra' 14 As the aromatic hydrocarbon group in 104 Among them, the aromatic hydrocarbon groups Ra' are the same as those in 14 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. Ra' 14 Examples of the substituent that may be possessed by Ra include 104 Examples of the substituents include the same as those that may be possessed by the group.

[0058] Ra' in formula (a1-r2-4) 14 When is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. Ra' in formula (a1-r2-4) 14 When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be any one of the 1st, 2nd, or 9th position of the anthryl group.

[0059] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0060] [ka]

[0061] [ka]

[0062] [ka]

[0063] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0064] [ka]

[0065] [ka]

[0066] [ka]

[0067] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0068] [ka]

[0069] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0070] [ka]

[0071] Tertiary alkyloxycarbonyl acid dissociating group: Among the polar groups, examples of the acid-dissociable group that protects the hydroxyl 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").

[0072] [ka] [In the formula, Ra' 7 ~Ra' 9 are each alkyl groups.

[0073] 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.

[0074] Secondary alkyl ester-type acid-labile group: Among the polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-4).

[0075] [ka] [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.

[0076] In the formula, Ra' 10 and Ra' 12 The hydrocarbon group in Ra' 3 The same can be mentioned. In the formula, Ra' 11a and Ra' 11b The alkyl group in Ra' is 1 The alkyl groups in the above formula (I) are the same as those in the above formula (I). In the formula, Ra' 10 and Ra' 12 The hydrocarbon group in 11a and Ra' 11b The alkyl group in may have a substituent. Examples of the substituent include the above-mentioned Ra x5 etc.

[0077] Ra' 10 and Ra' 11a or Ra' 11b may be bonded to each other to form a ring, which may be a polycyclic ring, a monocyclic ring, an alicyclic ring, or an aromatic ring. The alicyclic and aromatic rings may contain heteroatoms.

[0078] Ra' 10 and Ra' 11a or Ra' 11bAmong the above, the ring formed by bonding together is preferably a monocycloalkene, a ring in which some of the carbon atoms of a monocycloalkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), or a monocycloalkadiene, more preferably a cycloalkene having 3 to 6 carbon atoms, and more preferably cyclopentene or cyclohexene.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] Specific examples of the group represented by the formula (a1-r-4) are listed below.

[0083] [ka]

[0084] 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.

[0085] Of the above, preferred structural units (a1) are structural units derived from acrylate esters in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. Preferred specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1), (a1-2), or (a1-3).

[0086] [ka] [wherein 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 + is a monovalent hydrocarbon group. n a2 is an integer between 1 and 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 Rz is an acid-dissociable group represented by the above general formula (a1-r-1), (a1-r-2) or (a1-r-4). 01is 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. n is an integer of 0 or more, provided that n≦q×2+4.

[0087] In the formulas (a1-1) to (a1-3), the alkyl group of 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group of 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group of 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group of 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability and reducing the burden on the environment, a hydrogen atom or a methyl group is most preferred.

[0088] In the formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0089] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0090] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0091] Examples of the aliphatic hydrocarbon group containing a ring in its structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same as the straight-chain aliphatic hydrocarbon group or the branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, and tricyclo[5.2.1.0]. 2,6 ]decane, tetracyclododecane, and the like.

[0092] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such aromatic hydrocarbon groups preferably have 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (an arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (an aryl group) has been substituted with an alkylene group (for example, a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group, such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0093] 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.

[0094] In the formula (a1-2), Wa 1 n in a2 The monovalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity and may be saturated or unsaturated, but is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in their structure, and groups that combine linear or branched aliphatic hydrocarbon groups with aliphatic hydrocarbon groups containing a ring in their structure. The n a2 The +1 valence is preferably 2 to 4, more preferably 2 or 3. In the formula (a1-2), Ra 2 is preferably an acid-dissociable group represented by the above general formula (a1-r-1).

[0095] 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. Ya 001 is preferably an ester bond [-C(=O)-O-, -OC(=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 001is more preferably a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, or a single bond, and even more preferably a single bond.

[0096] 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. Ya 01 Among the above, Ya is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond. 01 is more preferably a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, or a single bond, and even more preferably a single bond.

[0097] 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.

[0098] In the formula (a1-3), Rz 01 The alkyl group, halogenated alkyl group, and alkoxy group in the formula (I) 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. Rz 01 The halogen atom in Rz is preferably an iodine atom. 01 The halogen atom of the halogenated alkyl group in the formula (I) is preferably a fluorine atom, an iodine atom, or a bromine atom, and more preferably a fluorine atom. Rz01 As the alkyl group, an alkoxy group or a hydroxy group is preferred, and a hydroxy group is more preferred.

[0099] 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 01 may be the same as or different from each other. 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 may be substituted with hydroxy groups. 001 , -Ya 01 -C(=O)-O-Ra 01 The substitution positions of the group and the hydroxy group are not particularly limited.

[0100] Specific examples of the structural unit (a1) are shown below. In each of the following formulas, R α represents a hydrogen atom or a methyl group.

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] In each of the following formulas, R α represents a hydrogen atom or a methyl group. Rz represents a hydrogen atom, an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxy group, or an alkoxy group.

[0111] [ka]

[0112] [ka]

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] 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 electron beam or EUV lithography. Among these, the 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.

[0117] Alternatively, the structural unit (a1) may include a structural unit represented by the following general formula (a1-1-1).

[0118] [ka] [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.]

[0119] In the formula (a1-1-1), R, Va 1 and n a1 represents R and Va in the formula (a1-1). 1 and n a1 is the same as:

[0120] The acid-dissociable group represented by 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, since this enhances reactivity and is suitable for use with EB or EUV.

[0121] The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol %, more preferably 10 to 75 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 70 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a1) is at least as large as 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 most the upper limit of the aforementioned preferred range, a balance with other structural units can be achieved, resulting in various favorable lithography properties.

[0122] Other structural units The component (A1) may contain other structural units in addition to the structural unit (a1) described above, as necessary. Examples of other structural units include a structural unit (a10) represented by general formula (a10-1) described below; a structural unit (a2) containing a lactone-containing cyclic group; a structural unit (a5) that generates acid upon exposure; a structural unit (a6) that has acid diffusion-controlling properties; and a structural unit (a8) derived from a compound represented by general formula (a8-1) described below.

[0123] Building block (a10): The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0124] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.] x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1.]

[0125] 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 viewpoints of industrial availability and reducing the burden on the environment, a hydrogen atom or a methyl group is particularly preferred.

[0126] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya 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.

[0127] Optionally substituted divalent hydrocarbon groups: The divalent hydrocarbon group which may have a substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0128] Aliphatic hydrocarbon groups The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in its structure.

[0129] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0130] 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.

[0131] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in its structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, 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 in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, and tricyclo[5.2.1.0]. 2,6 ]decane, tetracyclododecane, and the like.

[0132] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and still more preferably a methoxy group or an ethoxy group. 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 have been substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0133] Aromatic hydrocarbon groups The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene groups or heteroarylene groups); groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., groups in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0134] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom and halogenated alkyl group as the substituent include those exemplified as the substituent substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0135] Divalent linking groups containing heteroatoms: Examples of the divalent linking group containing a hetero atom include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2-, -S(=O)2-O-, and groups represented by the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or- Y 21 -S(=O)2-OY 22 -, wherein Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 1 to 3. 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, an acyl group, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or- Y 21 -S(=O)2-OY 22 -Medium, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same as those described above. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferred, a straight-chain alkylene group is more preferred, a straight-chain alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred. Y 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. Formula − [Y 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 - is a group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) 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.

[0136] Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond or an ester bond [-C(=O)-O-, -OC(=O)-].

[0137] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in the formula (n) is an aromatic ring which may have a substituent. ax1 Examples of the aromatic ring include groups 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 aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Also, Wa x1 The aromatic hydrocarbon group in (n) is selected from aromatic compounds containing an aromatic ring which may have two or more substituents (for example, biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1 As examples, benzene, naphthalene, anthracene, or biphenyl (nax1 A group in which (n +1) hydrogen atoms have been removed from benzene or naphthalene is preferred. ax1 A group obtained by removing (n +1) hydrogen atoms from benzene is more preferred. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0138] Wa x1 The aromatic hydrocarbon group in may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent include Ya x1 Examples of the substituent include the same as those exemplified as the substituent of the cyclic aliphatic hydrocarbon group in Wa. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1 The aromatic hydrocarbon group in the formula (I) preferably does not have a substituent.

[0139] In the formula (a10-1), n ax1 is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, further preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0140] Specific examples of the structural unit (a10) represented by the formula (a10-1) are shown below. In each of the following formulas, R α represents a hydrogen atom or a methyl group.

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] The structural unit (a10) contained in the component (A1) may be of one type, or may be of two or more types. The component (A1) may or may not contain the structural unit (a10), although it is preferable for the component (A1) to contain 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 %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a10) is at least as large as the lower limit of the above range, sensitivity can be further improved, while by ensuring that the proportion is at most the upper limit, it is easier to achieve a balance with other structural units.

[0145] Building block (a2): The component (A1) may or may not contain a structural unit (a2) that contains a lactone-containing cyclic group (provided that this does not fall under the category of structural unit (a1)). The lactone-containing cyclic group of the structural unit (a2) is effective in improving the adhesion of the resist film to the substrate when the component (A1) is used to form a resist film. Furthermore, the presence of the structural unit (a2) results in favorable lithography properties, for example, by appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0146] A "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and a group consisting of only a lactone ring is called a monocyclic group. If a group further contains other ring structures, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any suitable group can be used. Specific examples include groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0147] [ka] [In the formula, Ra' 21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, 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).

[0148] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21 The alkyl group in the formula (I) 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. Among 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, the alkoxy group in the formula (1) is preferably linear or branched. 21 Examples of the alkyl group include a group in which the alkyl groups mentioned above are linked to an oxygen atom (—O—). Ra' 21 The halogen atom in is preferably a fluorine atom. Ra' 21 The halogenated alkyl group in the formula Ra' is 21Examples 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.

[0149] Ra' 21 In the -COOR" and -OC(=O)R" groups, R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane; more specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; adamantane, norbornane, isobornane, or tricyclo[5.2.1.0 2,6 ] decane, tetracyclododecane, and other polycycloalkanes in which one or more hydrogen atoms have been removed. Examples of the lactone-containing cyclic group in R″ include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) above. Ra' 21 The hydroxyalkyl group in the formula (I) preferably has 1 to 6 carbon atoms, and specifically, the hydroxyalkyl group in the formula (I) is preferably a hydroxyalkyl group having 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.

[0150] Ra' 21 Among the above, each of the groups is preferably independently a hydrogen atom or a cyano group.

[0151] 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 straight-chain or branched-chain 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-CH2-, -CH2-O-CH2-, -S-CH2-, and -CH2-S-CH2-. 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.

[0152] Specific examples of the groups represented by the general formulae (a2-r-1) to (a2-r-7) are listed below.

[0153] [ka]

[0154] [ka]

[0155] 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 particularly preferred. Such a structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0156] [ka] [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.] 21 is a single bond or a divalent linking group. 21 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, where R' represents a hydrogen atom or a methyl group. 21 If -O-, Ya 21 does not become -CO-. Ra 21 is a lactone-containing cyclic group.

[0157] 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 viewpoints of industrial availability and reducing the burden on the environment, a hydrogen atom or a methyl group is particularly preferred.

[0158] 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.

[0159] 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.

[0160] In the formula (a2-1), Ya 21 is a single bond, and La 21 is preferably —COO— or —OCO—.

[0161] In the above formula (a2-1), Ra 21 is a lactone-containing cyclic group. Ra 21Suitable 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.

[0162] The structural unit (a2) contained in the component (A1) may be of one type, or may be of 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) relative to the total (100 mol%) of all structural units constituting the component (A1) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%. When the proportion of the structural unit (a2) is at least as great as the preferred lower limit, the effects achieved by including the structural unit (a2) can be fully obtained due to the effects described above. When the proportion of the structural unit (a2) is at most the upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0163] Building block (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 described below for the component (B1). Examples include structural units containing a structure represented by any of the general formulas (b-1) to (b-4) below. Suitable examples of the structural unit (a5) include structural units represented by general formula (a5-1) shown below.

[0164] [ka] [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. 50is a divalent hydrocarbon group which may have a substituent. a5 is an integer between 0 and 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.

[0165] {anion part} In the above 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. R 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 the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. 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.

[0166] In the above formula (a5-1), La 50 is a divalent linking group or a single bond. La 50The divalent linking group in the formula (I) 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, and each of these groups is the same as those described above for Ya x1 The divalent linking group is the same as the optionally substituted divalent hydrocarbon group and the divalent linking group containing a hetero atom exemplified in the above. Among the above, La 50 is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond. 5 is more preferably an ester bond [-C(=O)-O-, -OC(=O)-] or a single bond, and further preferably an ester bond [-C(=O)-O-, -OC(=O)-].

[0167] In the above formula (a5-1), Ra 50 is a divalent hydrocarbon group which may have a substituent. Ra 50 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0168] ··Ra 50 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in its structure.

[0169] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0170] 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.

[0171] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in its structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, and tricyclo[5.2.1.0]. 2,6 ]decane, tetracyclododecane, and the like.

[0172] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0173] ··Ra 50 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups (arylene groups or heteroarylene groups) in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle; groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group (aryl group or heteroaryl group) in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., groups in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0174] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and 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 the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0175] In the formula (a5-1), n a5 is an integer between 0 and 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 which may have a substituent. Or, among the above, Ra 50 is preferably an aromatic hydrocarbon group.

[0176] n a5 If is 2, then two Ra 50 may all be alicyclic hydrocarbon groups which may have a substituent, may all be aromatic hydrocarbon groups, or may be a combination of alicyclic hydrocarbon groups which may have a substituent and aromatic hydrocarbon groups.

[0177] In the above formula (a5-1), La 51 is a divalent linking group. La 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. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such divalent linking groups include 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) 50 The bond to V' in the following general formulas (L-al-1) to (L-al-8) is 101 is.

[0178] [ka] [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.

[0179] V' 102The 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.

[0180] V' 101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102 Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. 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 is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0181] La 51As for L-al-1, 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-al-1) to (L-al-5) and (L-al-8) are more preferable, and the linking group represented by (L-al-3) or (L-al-8) is even more preferable.

[0182] In the formula (a5-1), Ya 5 is a divalent linking group which may have a heteroatom, or a single bond. Ya 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. Ya 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 optionally substituted divalent hydrocarbon group and the divalent linking group containing a hetero atom exemplified in the above. Among the above, Ya 5 is preferably a linear or branched alkylene group or a single bond, and more preferably a single bond.

[0183] In the above formula (a5-1), Ra 51 and Ra 52 are each independently a hydrogen atom, a fluorine atom or a fluorinated alkyl group. Ra 51 and Ra 52 The fluorinated alkyl group in each of the above is preferably a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a trifluoromethyl group. In the above formula (a5-1), SO3 - 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.

[0184] In the formula (a5-1), n5 represents an integer of 1 to 4, and 1, 2, or 3 is preferable.

[0185] {cation part} In the above formula (a5-1), M' m+ represents an m-valent onium cation. Among these, M' m+ is preferably a sulfonium cation or an iodonium cation, and m is an integer of 1 or more.

[0186] Preferred cationic moieties ((M' m+ ) 1 / m ) includes organic cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[0187] [ka] [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 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. 201 represents -C(=O)- or -C(=O)-O-.]

[0188] In the above general formulas (ca-1) to (ca-3), R 201 ~R 207 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 The alkyl group in the formula (I) is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R201 ~R 207 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulae (ca-r-1) to (ca-r-7).

[0189] [ka] [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.

[0190] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0191] R' 201 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. R' 201Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R' 201 Specific examples of the aromatic hydrocarbon group in include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0192] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in 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 straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, the polycycloalkane includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0], and the like. 2,6 More preferred are 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.

[0193] 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.

[0194] 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 straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0195] Also, R' 201 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include lactone-containing cyclic groups represented by the above-mentioned general formulas (a2-r-1) to (a2-r-7), -SO2- containing cyclic groups represented by the below-mentioned general formulas (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16), respectively.

[0196] [ka]

[0197] R' 201 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, 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. As the halogen atom as a substituent, a fluorine atom is preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0198] A chain alkyl group which may have a substituent: R' 201 The chain alkyl group may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 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.

[0199] An optionally substituted chain alkenyl group: R' 201The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of 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 chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0200] 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:

[0201] R' 201 In addition to those mentioned above, the optionally substituted cyclic group, the optionally substituted chain alkyl group, or the optionally substituted chain alkenyl group also includes the same as the acid-dissociable group represented by formula (a1-r-2) above as the optionally substituted cyclic group or the optionally substituted chain alkyl group.

[0202] 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, and an —SO2- containing cyclic group represented by each of the general formulae (b5-r-1) to (b5-r-4) described below are preferred.

[0203] In the above general formulas (ca-1) to (ca-3), R 201 ~R203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they may not contain a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, or a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R N is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0204] 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.

[0205] R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in the formula (I) is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210The -SO2- containing cyclic group in 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), with "-SO2- containing polycyclic groups" being preferred and groups represented by general formula (b5-r-1) being more preferred.

[0206] [ka] [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 an -SO2- 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, and n' is an integer of 0 to 2. * represents a bond.

[0207] 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.

[0208] 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.

[0209] Specific examples of the groups represented by general formulae (b5-r-1) to (b5-r-4) are listed below, in which "Ac" represents an acetyl group.

[0210] [ka]

[0211] [ka]

[0212] [ka]

[0213] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas.

[0214] [ka]

[0215] [ka]

[0216] [ka] [In the formula, g1, g2, and g3 represent the number of repeating units, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[0217] [ka]

[0218] [ka]

[0219] [ka] [In the formula, R” 201is a hydrogen atom or a substituent, and the substituent is the same as R 201 ~R 207 , and R 210 ~R 212 The substituents are the same as those exemplified as the substituents that may be possessed by the group

[0220] [ka]

[0221] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0222] 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).

[0223] [ka]

[0224] The cation moiety ((M') in the formula (a5-1) m+ ) 1 / m ) is preferably a sulfonium cation, more preferably a cation represented by each of the formulas (ca-1) to (ca-3), still more preferably a cation represented by the formula (ca-1), and particularly preferably a cation represented by each of the formulas (ca-1-1) to (ca-1-84). In particular, from the viewpoint of achieving high sensitivity, the preferred cation represented by the formula (ca-1) is one having an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, or a sulfonyl group as a substituent, and for example, a cation selected from the group consisting of the cations represented by the above chemical formulas (ca-1-44), (ca-1-71) to (ca-1-84), respectively, is particularly preferred.

[0225] Specific preferred examples of the structural unit (a5) are shown below. In the following formula, R α represents a hydrogen atom or a methyl group. m+ represents m and M' in the above general formula (a5-1). m+ is the same as:

[0226] [ka]

[0227] [ka]

[0228] [ka]

[0229] 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 as large as the lower limit of the above-mentioned preferred range, it becomes easier to achieve even higher sensitivity and improved resolution, while when it is at most the upper limit of the above-mentioned preferred range, it becomes easier to achieve a balance with other structural units.

[0230] Building block (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 in 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.

[0231] 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 %, based on the total (100 mol %) of all structural units constituting the component (A1). When the proportion of the structural unit (a6) is at least as large as the lower limit of the above-mentioned preferred range, even higher sensitivity can be easily achieved, while when it is at most the upper limit of the above-mentioned preferred range, it is easier to achieve a balance with other structural units.

[0232] Building block (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 contain the structural unit (a8).

[0233] [ka] [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 R may form a condensed ring. 1 R 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 between 1 and 3.

[0234] 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.

[0235] The polymerizable group-containing group may be a group consisting of only a polymerizable group, or may be a group consisting 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 heteroatom. 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 A group represented by the formula - is preferred. 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.

[0236] Ya x2 and W 2 The fused ring formed by W 2 Polymerizable group of the site and Ya x2 and W 2 Other groups than the polymerizable group at the Ya site x2 and a fused ring formed by Ya x2 and W 2 The fused ring formed by these may have a substituent.

[0237] Specific examples of the structural unit (a8) are shown below. In the following formula, R α represents a hydrogen atom or a methyl group.

[0238] [ka]

[0239] 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).

[0240] The structural unit (a8) contained in the component (A1) may be of one type, or may be of two or more types. The component (A1) may or may not contain the structural unit (a8). The amount of the structural unit (a8) in the component (A1) relative to the total amount (100 mol %) of all structural units constituting the component (A1) is preferably within a range from 0 to 50 mol %, and more preferably from 0 to 30 mol %.

[0241] The component (A1) contained in the resist composition may use either a single type of compound, or a combination of two or more types of compounds.

[0242] 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).

[0243] 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%, even more preferably 30 to 70 mol%, and even more preferably 40 to 70 mol%. The proportion of the structural unit (a10) in the polymer 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 %, based on the total (100 mol %) of all structural units constituting the polymer compound.

[0244] In a polymeric compound composed of the structural unit (a1), the structural unit (a10), and the structural unit (a0), 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 85 mol%, even more preferably 30 to 70 mol%, and even more preferably 40 to 70 mol%. The proportion of the structural unit (a10) in the polymer 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 %, based on the total (100 mol %) of all structural units constituting the polymer compound. The proportion of the structural unit (a0) in the polymer 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 polymer compound.

[0245] In a polymeric compound composed of the structural unit (a1), the structural unit (a10), and the structural unit (a2), the proportion of the structural unit (a1) relative to the total (100 mol%) of all structural units constituting the polymeric compound is preferably 10 to 85 mol%, even more preferably 30 to 70 mol%, and even more preferably 40 to 70 mol%. The proportion of the structural unit (a10) in the polymer 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 %, based on the total (100 mol %) of all structural units constituting the polymer compound. The proportion of the structural unit (a2) in the polymer 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 polymer compound.

[0246] The component (A1) can be produced by dissolving the monomers that derive each structural unit in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the solution and polymerizing the resulting mixture. Examples of monomers that derive each structural unit include monomers that derive the structural unit (a10), monomers that derive the structural unit (a1), and monomers that derive any other structural unit (for example, the structural unit (a4), the structural unit (st), etc.). These monomers (for example, the monomers that derive the structural unit (a10)) may have protected hydroxyl groups, etc., as necessary. In this case, the component (A1) can be produced by carrying out a deprotection reaction after carrying out the polymerization reaction as described above. During polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH may be used in combination to introduce a -C(CF3)2-OH group to the terminal. Copolymers incorporating hydroxyalkyl groups, in which some of the alkyl group's hydrogen atoms are substituted with fluorine atoms, are effective in reducing development defects and LER (line edge roughness: unevenness on the line sidewalls).

[0247] The weight average molecular weight (Mw) of the component (A1) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and even more preferably 5,000 to 30,000. When the Mw of the component (A1) is less than or equal to the preferred upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is at least the preferred lower limit of this range, the compound exhibits good dry etching resistance and the cross-sectional shape of the resist pattern. The dispersity (Mw / Mn) of the component (A1) is not particularly limited, but is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.0, where Mn represents the number average molecular weight.

[0248] About ingredient (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) and whose solubility in a developer changes upon the action of an acid. There are no particular restrictions on the component (A2), and it can be selected from the many conventional base components for chemically amplified resist compositions. The component (A2) may be a high molecular weight compound or a low molecular weight compound, and may be used alone or in combination of two or more types.

[0249] 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, 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.

[0250] 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.

[0251] In this embodiment, the component (A) may contain a group represented by the following general formula (np1), (np2), or (np3) from the viewpoint of decomposability. In this embodiment, from the viewpoint of reducing the burden on the environment, it is preferable that the component (A) does not contain a trifluoromethyl group or a difluoromethylene group, and 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 In the above formula, it is preferable that Rpf does not contain a structure represented by the formula -. 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0252] [ka] [where, X 1 HA-OR 1 or -N(R 2 )R 1 represents X 2 represents a methyl group, an optionally substituted monovalent aromatic hydrocarbon group, -OR 3 , -SR 3 , or -NR 3 R 4 represents X 3 represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, a carbonyl group, -OR 1 , -SR 1 , or -N(R 2 )R 1 Represents R 1 represents a methylene group, a divalent aromatic hydrocarbon group which may have a substituent, or a carbonyl group. 2 , R 3 , and R 4 each independently represents a hydrogen atom, a methyl group, or a monovalent aromatic hydrocarbon group which may have a substituent.

[0253] In the formulas (np1), (np2), and (np3), X 1 -OR in 1 , -N(R 2 )R 1 or -N(R 1 In formula (2), O or N is bonded to CF3. In the formula (np2), X 2 -OR in 3 , -SR 3 , or -NR 3 R 4 In the formula, O, S, or N is bonded to CF2. In the formula (np2), X 3 -OR in 1 , -SR 1 , -N(R 2 )R 1 or -N(R 1 In the formula 2, the bond to CF2 is O, S, or N.

[0254] <Acid generator component (B)> The resist composition of this embodiment further contains, in addition to the component (A), an acid generator component (component (B)) that generates acid upon exposure. The component (B) includes a compound (B0) (hereinafter also referred to as "component (B0)") represented by the following general formula (b0):

[0255] [ka] [In the formula, Ar represents an aromatic ring. Rf 0 represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 0 represents a divalent linking group containing -C(=O)-O-, -OC(=O)- or -OS(=O)2-. 0 represents a cyclic group. 0 represents an organic group. n01 is an integer of 1 or more as long as the valence allows. n02 is an integer of 0 or more as long as the valence allows. However, L 0 -Yb 0 -OC(=O)-Yb 0 If Yb 0 is an alicyclic group which may have a substituent, a fused cyclic group of an aliphatic ring and an aromatic ring which may have a substituent, or an aromatic hydrocarbon group which has a substituent, and in the aromatic hydrocarbon group, at least one hydrogen atom of the aromatic ring is substituted with an alkyl group or an alkoxy group. 0 may be the same or different. When n02 is 2 or more, multiple Rb 0 may be the same or different, m is an integer of 1 or more, and M m+ represents an m-valent cation, where Rf 0 , L 0 , Yb 0 , Rb 0 and M m+ is the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 - does not include the structure represented by Rpf 1 ~Rpf 3are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0256] {anion part} In the formula (b0), the aromatic ring in Ar is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include, but are not limited to, pyridine rings, thiophene rings, and furan rings.

[0257] The aromatic ring in Ar is preferably an aromatic hydrocarbon ring, more preferably a benzene ring or a naphthalene ring, and even more preferably a benzene ring.

[0258] In the formula (b0), Rf 0 In the formula (I), the fluorinated alkyl group having 1 to 5 carbon atoms is preferably a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group, in which some of the hydrogen atoms have been substituted with fluorine atoms or —CHF.

[0259] Rf 0 is preferably a fluorine atom or —CH 2 F from the viewpoint of reducing the burden on the environment, and more preferably a fluorine atom from the viewpoint of compatibility with acid strength.

[0260] In the formula (b0), Rb 0The organic group in the formula (I) is a hydrocarbon group which may have a substituent. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, but is preferably an aliphatic hydrocarbon group.

[0261] Rb 0 The aliphatic hydrocarbon group in Rb 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. 0 The aliphatic hydrocarbon group in Rb may be saturated or unsaturated, but is preferably saturated. 0 The aliphatic hydrocarbon group in is preferably a linear or branched alkyl group.

[0262] Rb 0 The linear alkyl group in Rb preferably has 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms, and even more preferably 1 carbon atom. 0 The branched alkyl group in the formula (I) preferably has 3 or 4 carbon atoms, and more preferably 3 carbon atoms. Rb 0 The organic group in 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, and further preferably an ethyl group or a methyl group.

[0263] In the formula (b0), n01 is an integer of 1 or more as far as the valence allows. n01 is preferably 1 to 4, more preferably 2 to 4, even more preferably 3 or 4, and particularly preferably 4.

[0264] In the formula (b0), n02 is, as far as the valence allows, an integer of 0 or greater. n02 is preferably 0 to 3, more preferably 0 to 2, even more preferably 0 or 1, and particularly preferably 0.

[0265] In the above formula (b0), L 0Examples of the divalent linking group in L include -C(=O)-O-, -OC(=O)-, and -OS(=O)2-, as well as combinations of one or more of these with an alkylene group. 0 When the divalent linking group in is -C(=O)-O-, -OC(=O)-, or -OS(=O)2-, L 0 -Yb 0 is -C(=O)-O-Yb 0 , -OC(=O)-Yb 0 , or -OS(=O)2-Yb 0 is. L 0 is a combination of one or more of -C(=O)-O-, -OC(=O)-, and -OS(=O)2- with an alkylene group, the alkylene group may be linear or branched.

[0266] L 0 Examples of the divalent linking group in the formula (L0-1) include linking groups represented by the following general formula (L0-1).

[0267] [ka] [In the formula, Lb 01 and Lb 02 each independently represents a single bond or an alkylene group having 1 to 5 carbon atoms; L 01 represents -C(=O)-O-, -OC(=O)-, or -OS(=O)2-; n03 represents an integer of 1 to 3. However, when n03 is 2 or 3, Lb 01 When n03 is 2 or 3, multiple Lb 0 may be the same or different. When n03 is 2 or more, multiple L 01 may be the same or different. * represents a bond bonded to Ar in the formula (b0), and ** represents a bond bonded to Yb in the formula (b0). 01 is a bond that bonds to .]

[0268] In the above formula (L0-1), Lb 01 and Lb 02The alkylene group having from 1 to 5 carbon atoms in Lb may be linear or branched, but is preferably linear. 01 and Lb 02 The linear alkylene group in Lb preferably has 1 to 3 carbon atoms, and more preferably 1 or 2 carbon atoms. 01 and Lb 02 The branched alkylene group in the formula (I) preferably has 2 to 4 carbon atoms, and more preferably has 2 or 3 carbon atoms.

[0269] In the formula (L0-1), n03 is preferably 1 or 2, and more preferably 1.

[0270] L 0 Examples of the divalent linking group in the formula (L01-1) include linking groups represented by the following general formulae (L01-1) to (L03-1).

[0271] [ka] [In the formula, Lb 011 ~Lb 031 Lb each independently represents a single bond or an alkylene group having 1 to 5 carbon atoms. 012 ~Lb 032 each independently represents a single bond or a divalent linking group. nb01 to nb03 each independently represents an integer of 1 to 3. However, when nb01 to nb03 are 2 or 3, Lb 011 ~Lb 031 When nb01 is 2 or 3, multiple Lb 011 may be the same or different. When nb02 is 2 or 3, multiple Lb 021 may be the same or different. When nb03 is 2 or 3, multiple Lb 031 may be the same or different. * represents a bond bonded to Ar in the general formula (b0), and ** represents a bond bonded to Yb in the general formula (b0). 0 represents a bond to the atom.]

[0272] In the formulae (L01-1) to (L01-3), Lb 011 ~Lb031 As the alkylene group having 1 to 5 carbon atoms, Lb 01 The same can be mentioned. In the formulae (L01-1) to (L01-3), Lb 012 ~Lb 032 Examples of the divalent linking group in the formula (L0-1) include alkylene groups having 1 to 5 carbon atoms which may have -C(=O)-O-, -OC(=O)-, or -OS(=O)2-. Examples of the alkylene group having 1 to 5 carbon atoms include Lb 01 The same can be mentioned. In the formulae (L01-1) to (L01-3), nb01 to nb03 are preferably 1 or 2, and more preferably 1.

[0273] L in the formula (b0) 0 Examples of the group include groups represented by any of the following general formulae (L0-1-1) to (L0-1-5).

[0274] [ka] [In the formula, Vb 01 and Vb 02 each independently represents a single bond or an alkylene group having 1 to 5 carbon atoms. 03 represents an alkylene group having 1 to 5 carbon atoms. * represents a bond bonded to Ar in the formula (b0), and ** represents a bond bonded to Yb in the formula (b0). 01 is a bond that bonds to .]

[0275] In the above formulas (L0-1-1) to (L0-1-5), Vb 01 and Vb 02 The alkylene group having 1 to 5 carbon atoms in Vb may be linear or branched, but is preferably linear. 01 and Vb 02 The linear alkylene group in Vb preferably has 1 to 3 carbon atoms, and more preferably 1 or 2 carbon atoms. 01 and Vb 02The branched alkylene group in the formula (I) preferably has 2 to 4 carbon atoms, and more preferably has 2 or 3 carbon atoms.

[0276] ≪Yb 0 About≫ L 0 -Yb 0 -OC(=O)-Yb 0 If not: L 0 -Yb 0 -OC(=O)-Yb 0 otherwise, Yb 0 is a cyclic group. Yb 0 The cyclic group in (I) is preferably a cyclic hydrocarbon group. The cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group is preferably saturated.

[0277] Yb 0 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. Yb 0 Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Yb 0 Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group 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 (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0278] Yb 0 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in 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 straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more 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 one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is preferably a polycycloalkane having a bridged ring polycyclic skeleton, such as adamantane, norbornane, isobornane, bornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0279] Yb 0 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group, a norbornyl group, or a bornyl group, and particularly preferably an adamantyl group.

[0280] 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. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group 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. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0281] Also, Yb 0 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, -SO2- containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) below, and heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) below. In the formula, * represents L in formula (b0). 0 represents a bond bonded to

[0282] [ka] [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 an -SO2- 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, and n' is an integer of 0 to 2. * represents a bond.

[0283] [ka]

[0284] 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.

[0285] 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 each independently preferably a hydrogen atom or a cyano group.

[0286] Specific examples of the groups represented by general formulae (b5-r-1) to (b5-r-4) are listed below, in which "Ac" represents an acetyl group.

[0287] [ka]

[0288] [ka]

[0289] [ka]

[0290] Yb 0 The cyclic group in may have a substituent, for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, etc. 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. As the halogen atom as a substituent, a fluorine atom, a bromine atom, or an iodine atom is preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0291] Yb 0The cyclic hydrocarbon group in may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a bridged ring polycyclic skeleton to which one or more aromatic rings are fused. Specific examples of the bridged ring polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. 0 Specific examples of the fused ring group in the formula (b0) include groups represented by the following formulas (r-br-1) to (r-br-2). 0 Rx represents the bond that connects to 0 represents a substituent.

[0292] [ka]

[0293] Yb 0 Examples of the substituent that the fused cyclic group in the formula (I) may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group. Examples of the alkyl group, alkoxy group, halogen atom and halogenated alkyl group as the substituent of the fused cyclic group include the same as those exemplified as the substituent of the cyclic group. Examples of the aromatic hydrocarbon group as the substituent of the fused ring 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 groups in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane; groups in which one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane; lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above; —SO2- containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) above; and heterocyclic groups represented by the formulae (r-hr-7) to (r-hr-16) above.

[0294] The substituent of the fused cyclic group may be an alkyl group partially substituted with a heteroatom-containing group. In the alkyl group as a substituent of the fused cyclic group, for example, some of the hydrogen atoms may be substituted with a heteroatom-containing group. Alternatively, in the alkyl group as a substituent of the fused cyclic group, some of the carbon atoms (e.g., methylene groups) constituting the hydrocarbon chain may be substituted with a heteroatom-containing group. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms.

[0295] Examples of the heteroatom-containing group that substitutes a hydrogen atom of an alkyl group include a hydroxyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a carboxy group.

[0296] Examples of heteroatom-containing groups substituting carbon atoms constituting the hydrocarbon chain of an alkyl group include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, -S(=O)2-O-, etc. Preferred heteroatom-containing groups are -O-, -C(=O)-O-, -OC(=O)-, and -S(=O)2-O-, with -C(=O)-O- being more preferred.

[0297] The substituent of the fused ring group is -C(=O)-O-Rx 01 Examples of such groups include groups represented by Rx 01represents an alkyl group, which may be linear, branched, or cyclic. Examples of linear alkyl groups include those having 1 to 5 carbon atoms, with methyl, ethyl, n-propyl, and n-butyl being preferred. Examples of branched alkyl groups include those having 3 to 5 carbon atoms, with isopropyl, tert-butyl, sec-butyl, and isobutyl being preferred. Examples of cyclic alkyl groups include those in which one hydrogen atom has been removed from a cycloalkane having 1 to 8 carbon atoms, with cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl being preferred, and cyclopentyl and cyclohexyl being more preferred.

[0298] Yb 0 Examples of the substituted cyclic groups include an adamantyl group which may have a substituent; a cyclic group having a steroid skeleton which may have a substituent; a lactone-containing cyclic group represented by each of the formulae (a2-r-1) to (a2-r-7); an -SO2- containing cyclic group represented by each of the formulae (a5-r-1) to (a5-r-4); a fused cyclic group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused; and an aromatic hydrocarbon group which may have a substituent. The fused cyclic group is preferably a group represented by the formula (r-br-1) or (r-br-2). Substituents for the adamantyl group include a hydroxy group and a carbonyl group.

[0299] L 0 -Yb 0 -OC(=O)-Yb 0 If not L 0 Examples of the linking group include a divalent linking group containing -C(=O)-O-; a divalent linking group containing -S(=O)2-O-; a group represented by the formula (L0-3) (wherein nb03 is 1 and Lb 031 and Lb 032are all single bonds). Examples of the divalent linking group containing -C(=O)-O- include a group represented by the formula (L01-1) above, and preferably a group represented by the formula (L0-1-1), (L0-1-2) or (L0-1-5). Examples of the divalent linking group containing -S(=O)2-O- include a group represented by the formula (L0-2) above, and preferably a group represented by the formula (L0-1-4) or (L0-1-5).

[0300] L 0 -Yb 0 -OC(=O)-Yb 0 If: In this case, Yb 0 is an alicyclic group which may have a substituent, a fused ring group of an aliphatic ring and an aromatic ring which may have a substituent, or an aromatic hydrocarbon group which has a substituent. In the aromatic hydrocarbon group, at least one hydrogen atom of the aromatic ring is substituted with an alkyl group or an alkoxy group.

[0301] Yb 0 The alicyclic group which may have a substituent in "L 0 -Yb 0 -OC(=O)-Yb 0 Examples of the alicyclic group include groups in which one or more hydrogen atoms have been removed from a monocycloalkane or polycycloalkane; cyclic groups having a steroid skeleton; lactone-containing cyclic groups represented by the aforementioned formulae (a2-r-1) to (a2-r-7); —SO2- containing cyclic groups represented by the aforementioned formulae (a5-r-1) to (a5-r-4); and heterocyclic groups represented by the aforementioned chemical formulae (r-hr-1) to (r-hr-16). Yb 0 The substituents of the alicyclic group include "L 0 -Yb 0 -OC(=O)-Yb 0 Examples of cases where the above is not the case include "if

[0302] Yb 0 The fused ring group of an aliphatic ring and an aromatic ring in 0 -Yb 0-OC(=O)-Yb 0 Examples of the fused cyclic group include the groups represented by the formula (r-br-1) or (r-br-2) above. Yb 0 The substituents of the fused ring group include "L 0 -Yb 0 -OC(=O)-Yb 0 Examples of cases where the above is not the case include "if

[0303] Yb 0 The aromatic hydrocarbon group having a substituent in "L 0 -Yb 0 -OC(=O)-Yb 0 However, in the aromatic hydrocarbon group, at least one hydrogen atom of the aromatic ring is substituted with an alkyl group or an alkoxy group. The aromatic ring may have an alkyl group, an alkoxy group, or both an alkyl group and an alkoxy group. The aromatic ring preferably has an alkoxy group.

[0304] The aromatic ring may have a substituent other than an alkyl group or an alkoxy group. Examples of the substituent include a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. Among these, the aromatic ring preferably has a halogen atom as a substituent, and more preferably has an iodine atom as a substituent.

[0305] Yb 0 The aromatic ring contained in the aromatic hydrocarbon group in the formula (I) is preferably a benzene ring or a naphthalene ring, more preferably a benzene ring.

[0306] L 0 -Yb 0 -OC(=O)-Yb 0 In this case, the formula (b0) can be expressed by the following formula (b02-1).

[0307] [ka] [In the formula, Ar, Rf 0 , n01, and n02 are Ar, Rf in the formula (b0). 0 , n01, and n02, respectively. 00 is an alicyclic group which may have a substituent, a fused ring group of an aliphatic ring and an aromatic ring which may have a substituent, or an aromatic hydrocarbon group which has a substituent, and in the aromatic hydrocarbon group, at least one hydrogen atom of the aromatic ring is substituted with an alkyl group or an alkoxy group. m is an integer of 1 or more, and M m+ represents an m-valent cation, where Rf 0 , Rb 0 and M m+ is the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 - does not include the structure represented by Rpf 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0308] From the viewpoint of sensitivity and CDU, Yb 0 As the group, a fused ring group of an aliphatic ring and an aromatic ring, which may have a substituent, is preferred, and a group represented by the above formula (r-br-1) or (r-br-2) is more preferred.

[0309] In the general formula (b0), Rf 0 , L 0 , Yb 0 , Rb 0 and M m+ is the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 - does not include the structure represented by Rpf 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0310] The component (B0) is preferably a compound represented by the following general formula (b0-1).

[0311] [ka] [In the formula, Rf 01 represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 01 represents a divalent linking group containing -C(=O)-O-, -OC(=O)- or -OS(=O)2-. 01 represents a cyclic group. 01 represents an organic group. n011 is an integer of 1 or more, n021 is an integer of 0 or more, and n011+n022≦4. However, L 01 -Yb 01 -OC(=O)-Yb 01 If Yb 01 is an alicyclic group which may have a substituent, a fused cyclic group of an aliphatic ring and an aromatic ring which may have a substituent, or an aromatic hydrocarbon group which has a substituent, and in the aromatic hydrocarbon group, at least one hydrogen atom of the aromatic ring is substituted with an alkyl group or an alkoxy group. 01 may be the same or different. When n021 is 2 or more, multiple Rb 01 may be the same or different, m is an integer of 1 or more, and M m+ represents an m-valent cation, where Rf 01 , L 01 , Yb 01 , Rb 01 and M m+ is the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 - does not include the structure represented by Rpf 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0312] In the formula (b0-1), Rf 01 , Rb 01 ,L 01 , and Yb 01 is Rf in the formula (b0). 0 , Rb01 ,L 0 , and Yb 0 are the same as above. n011 is preferably an integer of 1 to 4, more preferably an integer of 2 to 4, further preferably 3 or 4, and particularly preferably 4. n021 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, further preferably 0 or 1, and particularly preferably 0.

[0313] The component (B0) is more preferably a compound represented by the following general formula (b0-1-1).

[0314] [ka] [In the formula, L 01 and Yb 01 is L in the formula (b0-1). 01 and Yb 01 m is an integer equal to or greater than 1, and M m+ represents an m-valent organic cation, where L 01 , Yb 01 and M m+ is the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 - does not include the structure represented by Rpf 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0315] Specific examples of the component (B0) are shown below, but are not limited to these. In the following formula, m is an integer of 1 or more, and M m+ represents an m-valent cation.

[0316] [ka]

[0317] [ka]

[0318] [ka]

[0319] {cation part} In the above formula (b0), M m+ represents an m-valent onium cation. The onium cation is preferably a sulfonium cation or an iodonium cation. m is an integer of 1 or more.

[0320] Preferred cationic moieties ((M m+ ) 1 / m ) includes organic cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[0321] [ka] [In the formula, R 201 ~R 207 R each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. 201 ~R 203 , R 206 ~R 207 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 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted SO2-containing cyclic group. 201 represents -C(=O)- or -C(=O)-O-.]

[0322] In the above general formulas (ca-1) to (ca-3), R 201 ~R 207 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207The alkyl group in the formula (I) is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulae (ca-r-1) to (ca-r-7).

[0323] [ka] [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.

[0324] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0325] R' 201 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. R' 201Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R' 201 Specific examples of the aromatic hydrocarbon group in include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0326] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in 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 straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more 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 one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a bridged ring polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0327] 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.

[0328] 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 straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0329] Also, R' 201 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include the lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, the —SO—-containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) above, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) above.

[0330] R' 201 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, 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. As the halogen atom as a substituent, a fluorine atom is preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0331] A chain alkyl group which may have a substituent: R' 201 The chain alkyl group may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 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.

[0332] An optionally substituted chain alkenyl group: R' 201 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl 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 chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0333] 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:

[0334] R' 201 In addition to those mentioned above, the optionally substituted cyclic group, the optionally substituted chain alkyl group, or the optionally substituted chain alkenyl group also includes the same as the acid-dissociable group represented by formula (a1-r-2) above as the optionally substituted cyclic group or the optionally substituted chain alkyl group.

[0335] 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), or an —SO2- containing cyclic group represented by each of the general formulae (a5-r-1) to (a5-r-4) is preferred.

[0336] In the above general formulas (ca-1) to (ca-3), R 201 ~R 203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they may not contain a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, or a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R Nis an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, 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.

[0337] 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.

[0338] R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted SO2-containing cyclic group. R 210 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in the formula (I) is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210 As the optionally substituted SO2-containing cyclic group in the above, an "-SO2-containing polycyclic group" is preferred, and a group represented by the above general formula (a5-r-1) is more preferred.

[0339] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-67).

[0340] [ka]

[0341] [ka]

[0342] [ka] [In the formula, g1, g2, and g3 represent the number of repeating units, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[0343] [ka]

[0344] [ka]

[0345] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the same as R 201 ~R 207 , and R 210 The substituents are the same as those exemplified as the substituents that may be possessed by the group

[0346] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0347] 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).

[0348] [ka]

[0349] Among the above, the cation part ((M m+ ) 1 / m ) is preferably a cation represented by general formula (ca-1).

[0350] Specific examples of the component (B0) are shown below, but are not limited to these.

[0351] [ka]

[0352] [ka]

[0353] [ka]

[0354] [ka]

[0355] In the resist composition of this embodiment, the component (B0) may be used alone, or in combination of two or more different compounds. In the resist composition of this embodiment, the amount of the component (B0) relative to 100 parts by mass of the component (A) is preferably 3 to 40 parts by mass, more preferably 5 to 40 parts by mass, even more preferably 10 to 40 parts by mass, and particularly preferably 15 to 35 parts by mass. When the amount of component (B0) is at least as large as the lower limit of this preferred range, lithography properties such as sensitivity and reduced CDU are further improved during resist pattern formation. On the other hand, when the amount is no more than the upper limit of this preferred range, a homogeneous solution is more easily obtained when the components of the resist composition are dissolved in an organic solvent, and the storage stability of the resist composition is further improved.

[0356] The proportion of the (B0) component in the entire (B) component is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 95% by mass or more, and may be 100% by mass.

[0357] The component (B) may contain an acid generator component (B1) (hereinafter also referred to as "component (B1)") other than the component (B0) described above. Examples of the component (B1) include various types of acid generators, such as onium salt-based acid generators such as iodonium salts and sulfonium salts; oxime sulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisaryl sulfonyl diazomethanes and poly(bissulfonyl) diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0358] In the resist composition of this embodiment, the component (B1) may use either a single type, or a combination of two or more types. When the resist composition of this embodiment contains the component (B1), the proportion of the component (B1) in the entire component (B) is preferably less than 50 mass%, more preferably 40 mass% or less, even more preferably 30 mass% or less, and particularly preferably less than 20 mass%. From the standpoint of environmental impact, it is preferable that the resist composition of this embodiment does not contain the component (B1).

[0359] In this embodiment, from the viewpoint of reducing the burden on the environment, the component (B) is represented by the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 In the above formula, it is preferable that Rpf does not contain a structure represented by the formula -. 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent. <Base component (D)> 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 acid diffusion controllability, 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 occurrence of coating defects.

[0360] Regarding component (D1) The component (D1) is not particularly limited as long as it decomposes upon exposure to light 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) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion control properties (basicity), but act as quenchers in the unexposed areas of the resist film.

[0361] [ka] [In the formula, Rd 1 ~Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 2 In this case, no fluorine atom is bonded to the carbon atom adjacent to the S atom. 1 is a single bond or a divalent linking group; m is an integer of 1 or more; M m+are each independently an m-valent organic cation.

[0362] {(d1-1) component} Anion part In formula (d1-1), Rd 1 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 each of the R' 201 The same can be mentioned. Among these, Rd 1 is 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 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 the following formulas (y-al-1) to (y-al-5), respectively. Note that Rd 1 In the case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group has a linking group represented by the following general formulas (y-al-1) to (y-al-7) as a substituent, in the following general formulas (y-al-1) to (y-al-7), Rd 1 The carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the formula (y-al-1) to (y-al-7) is bonded to V' 101 is.

[0363] [ka] [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.

[0364] 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.

[0365] V' 101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102 Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. 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 is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0366] Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and another ring structure). The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include straight-chain alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched-chain alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0367] When the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, and nitrogen atoms.

[0368] Preferred examples of the anion moiety of the component (d1-1) are shown below.

[0369] [ka]

[0370] Cation part In formula (d1-1), M m+ is an m-valent organic cation. M m+Suitable organic cations include those similar to those 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-1-75) being even more preferred. The component (d1-1) may be used alone or in combination of two or more.

[0371] {(d1-2) component} Anion part 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 R' 201 The same can be mentioned. However, Rd 2 In this case, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not fluorinated), which makes the anion of component (d1-2) an appropriately weak acid anion, thereby improving the quenching ability of component (D). Road 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.

[0372] The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group is preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor.

[0373] Road 2 The hydrocarbon group may have a substituent, and the substituent may be Rd 1Examples 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.

[0374] Preferred examples of the anion moiety of the component (d1-2) are shown below.

[0375] [ka]

[0376] Cation part In formula (d1-2), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-2) may be used alone or in combination of two or more.

[0377] {(d1-3) component} Anion part 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 The Rd is preferably a fluorine atom-containing cyclic group, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferred, and the Rd 1 The same fluorinated alkyl groups as those mentioned above are more preferred.

[0378] 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 R' 201 The same can be mentioned. Among these, alkyl groups, alkoxy groups, alkenyl groups and cyclic groups which may have a substituent are preferred. Road 4The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. 4 A portion of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Road 4 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0379] Road 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.

[0380] Road 4 The cyclic group in the formula (I) is the same as the R' 201 Examples of the cyclic group include the same as the cyclic group in the above, and preferred are alicyclic groups obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or aromatic groups such as a phenyl group or a naphthyl group. 4 When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in excellent lithography properties. 4 When is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency, and exhibits favorable sensitivity and lithography properties.

[0381] In formula (d1-3), Yd 1 is a single bond or a divalent linking group. Yd 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 groups which may have a substituent and divalent linking groups containing a hetero atom as those mentioned in the description of the divalent linking group in the above. Yd 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.

[0382] Preferred examples of the anion moiety of the component (d1-3) are shown below.

[0383] [ka]

[0384] [ka]

[0385] Cation part In formula (d1-3), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-3) may be used alone or in combination of two or more.

[0386] The component (D1) may be any one of the components (d1-1) to (d1-3) above, 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 relative to 100 parts by mass of the component (A) is preferably 0.5 to 15 parts by mass, more preferably 1 to 12 parts by mass, and even more preferably 2 to 10 parts by mass.

[0387] The component (D1) preferably contains the component (d1-1) above. The content of the component (d1-1) in the entire component (D1) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The component (D1) may consist solely of the compound component (d1-1).

[0388] Manufacturing method of component (D1): The method for producing the components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods. The method for producing component (d1-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0389] Regarding component (D2) The component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the component (D1) above. The component (D2) is not particularly limited as long as it acts as an acid diffusion controller and does not fall under the category of component (D1), and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are particularly preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms. Examples of aliphatic amines include amines in which at least one hydrogen atom of ammonia NH3 has been substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), and cyclic amines. Specific examples of alkylamines and alkyl alcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0390] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. The aliphatic polycyclic amine is preferably one having 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0391] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, and triethanolamine triacetate, with triethanolamine triacetate being preferred.

[0392] Furthermore, an aromatic amine may be used as the component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, 2,6-di-tert-butylpyridine, and 2,6-di-tert-butylpyridine.

[0393] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), the amount of the component (D2) within the resist composition is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A1). By ensuring this range, the resist pattern shape and stability over time during storage can be improved.

[0394] In this embodiment, from the viewpoint of reducing the burden on the environment, the component (D) is a compound represented by the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 In the above formula, it is preferable that Rpf does not contain a structure represented by the formula -. 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0395] <<At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and derivatives thereof>> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, and phosphorus oxo acids and derivatives thereof (hereafter referred to as "component (E)") for the purposes of preventing sensitivity degradation and improving the resist pattern shape and stability over time after exposure. 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 oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred.

[0396] In the resist composition of this embodiment, the component (E) may be used either as a single type, or in combination of two or more types. 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 setting the amount within this range, lithography properties are further improved.

[0397] In this embodiment, the component (E) may contain a group represented by the above general formula (np1), (np2), or (np3) from the viewpoint of decomposability. In this embodiment, from the viewpoint of reducing the burden on the environment, it is preferable that the component (E) does not contain a trifluoromethyl group or a difluoromethylene group, and 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 In the above formula, it is preferable that Rpf does not contain a structure represented by the formula -. 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0398] <Fluorine additive component (F)> The resist composition of this embodiment contains a fluorine additive component (hereafter referred to as "component (F)") as a hydrophobic resin. Component (F) is used to impart water repellency to the resist film, and when used as a resin separate from component (A), it can improve lithography properties. In this embodiment, the component (F) contains a fluororesin component (F1) having a structural unit (f1) that includes a base dissociable group.

[0399] <Constituent unit (f1)> The structural unit (f1) containing a base dissociable group contains at least one selected from the group consisting of a structural unit (f1-1) represented by the following general formula (f1-1), a structural unit (f1-2) represented by the following general formula (f1-2), and a structural unit (f1-3) represented by the following general formula (f1-3):

[0400] [ka] [wherein each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Lf 1 and Lf 2 are each independently a divalent linking group not containing an acid-labile group; Rf 1 and Rf 3 are each independently an organic group having a fluorine atom; Rf 2 is a monovalent organic group, provided that Lf 2 and Rf 2 at least one of A is a group in which some or all of the hydrogen atoms are substituted with fluorine atoms; aryl is a divalent aromatic hydrocarbon group which may have a substituent; Lf 3 is a divalent linking group that does not have a single bond or a polycyclic structure and does not contain an acid-dissociable group.

[0401] In the formulas (f1-1) to (f1-3), the alkyl group having 1 to 5 carbon atoms for 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 for R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being particularly preferred. 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, more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.

[0402] In the formulas (f1-1) and (f1-2), Lf 1 and Lf 2 are each independently a divalent linking group that does not contain an acid-dissociable group. The "acid dissociable site" refers to a site in the organic group that dissociates when exposed to an acid, like the "acid dissociable group" described above. That is, the O atom of (-C(=O)-O-) bonded to the main chain and Lf 1 and Lf 2 However, it does not dissociate under the action of acid.

[0403] Lf 1 and Lf 2 Examples of the divalent linking group not having an acid-dissociable site in Lf include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. 1 and Lf 2 It is preferable that the divalent linking group having no acid dissociable site in the formula (I) does not have a polycyclic structure.

[0404] Optionally substituted divalent hydrocarbon groups: Lf 1 and Lf 2 When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0405] Lf 1 and Lf 2 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in its structure.

[0406] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, and even more preferably 3 or 4 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)- and -CH(CH2CH3)-; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)- and -CH(CH2CH3)CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0407] 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.

[0408] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in its structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a monocyclic group or a polycyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and examples of the polycycloalkane include polycycloalkanes having a fused ring polycyclic skeleton, such as decalin, perhydroazulene, perhydroanthracene, and a ring structure having a steroid skeleton.

[0409] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and still more preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, such as -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0410] Lf 1 and Lf 2 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this carbon number does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene groups or heteroarylene groups); groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., groups in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0411] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom and halogenated alkyl group as the substituent include those exemplified as the substituent substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0412] Divalent linking groups containing heteroatoms: Lf 1 and Lf 2 is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2-, -S(=O)2-O-, and groups represented by the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or- Y 21 -S(=O)2-OY 22 -, wherein Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 0 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, an acyl group, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or- Y 21 -S(=O)2-OY 22 -Medium, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the above-mentioned Lf 1 and Lf 2 Examples of the divalent linking group include the same groups as those (divalent hydrocarbon groups which may have a substituent) mentioned in the description of the divalent linking group in the above. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferred, a straight-chain alkylene group is more preferred, a straight-chain alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred. Y 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. Formula − [Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, in the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by - is a group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) 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.

[0413] Among the above, Lf 1 and Lf 2 is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group which may have a substituent, or a combination thereof, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may have a substituent, and even more preferably a linear alkylene group having 1 to 10 carbon atoms or a branched fluorinated alkylene group having 1 to 10 carbon atoms.

[0414] In the formula (f1-2), Rf 2 Examples of the monovalent organic group in P1 , -Rf P2 -Rf P1 , -CH(-Rf P1 )2, -Rf P2 -O-Rf P1 , -Rf P2 -C(=O)-Rf P1 , -Rf P2 -C(=O)-ORf P1 , -Rf P2 -OC(=O)-Rf P1 etc. where Rf P1 is a monovalent linear or branched alkyl group, a monovalent alicyclic hydrocarbon group, or a monovalent aromatic hydrocarbon group. P1 may be the same or different. Rf P1 Some or all of the hydrogen atoms of the linear or branched alkyl group, monovalent alicyclic hydrocarbon group and aromatic hydrocarbon group in the formula (I) may be substituted with a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, a carbonyl group, or the like.

[0415] Rf P2 is a single bond, a divalent linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group. Rf P2 Some or all of the hydrogen atoms in the divalent linear or branched alkylene group, divalent alicyclic hydrocarbon group, or divalent aromatic hydrocarbon group may be substituted with a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, a carbonyl group, or the like.

[0416] Rf P1 The monovalent linear or branched alkyl group preferably has 1 to 40 carbon atoms, more preferably 1 to 20 carbon atoms, and even more preferably 1 to 12 carbon atoms. Specific examples of the monovalent linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. Specific examples of the monovalent 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.

[0417] Rf P1 In the above, the monovalent alicyclic hydrocarbon group includes a monovalent monocyclic alicyclic hydrocarbon group and a monovalent polycyclic alicyclic hydrocarbon group, but does not include an alicyclic group having a crosslinked structure.

[0418] Specific examples of the monovalent monocyclic alicyclic hydrocarbon group include 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.

[0419] Specific examples of the monovalent polycyclic alicyclic hydrocarbon group include groups in which one hydrogen atom has been removed from a polycycloalkane, such as decalin, perhydroazulene, perhydroanthracene, and polycycloalkanes having a fused ring polycyclic skeleton, such as a ring structure having a steroid skeleton.

[0420] Rf P1 In the above formula, examples of the monovalent aromatic hydrocarbon group include groups in which one hydrogen atom has been removed from an aromatic ring. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

[0421] Rf P2 In the formula (I), the divalent linear or branched alkylene group, the divalent alicyclic hydrocarbon group, or the divalent aromatic hydrocarbon group includes the above-mentioned Lf 1 and Lf 2 The same as those described above can be mentioned.

[0422] Among the above, Rf 2 is -Rf P1 , -Rf P2 -Rf P1 , -CH(-Rf P1 )2 is preferred.

[0423] The above-mentioned Lf 2 and Rf 2 At least one of the groups is a hydrocarbon group in which some or all of the hydrogen atoms have been substituted with fluorine atoms. 2 and Rf 2Preferably, the hydrocarbon group contains a group in which some or all of the hydrogen atoms have been substituted with fluorine atoms.

[0424] In the formulas (f1-1) and (f1-3), Rf 1 and Rf 3 The organic group having a fluorine atom in Rf 2 Among the monovalent organic groups in the above, those having a fluorine atom are preferred. 1 and Rf 3 is -Rf P11 , -Rf P21 -Rf P11 , -CH(-Rf P11 )2 is preferred. In the formula, Rf P11 is a monovalent linear or branched alkyl group having a fluorine atom, a monovalent alicyclic hydrocarbon group having a fluorine atom, or a monovalent aromatic hydrocarbon group having a fluorine atom. P11 Rf may be the same or different. P11 The monovalent linear or branched alkyl group having a fluorine atom, the monovalent alicyclic hydrocarbon group having a fluorine atom, or the monovalent aromatic hydrocarbon group having a fluorine atom has the same structure as the above Rf except that it has a fluorine atom. p1 is the same as: Rf P21 is a single bond, a divalent linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, and P2 is the same as:

[0425] In the formula (f1-3), A aryl Examples of the group include a group in which two hydrogen atoms have been removed from an aromatic hydrocarbon ring which may have a substituent. A aryl The ring skeleton of the aromatic cyclic group in the formula (I) preferably has 6 to 15 carbon atoms, and examples thereof include a benzene ring, a naphthalene ring, a phenanthrene ring, an anthracene ring, etc. Among these, a benzene ring or a naphthalene ring is particularly preferred. A arylIn the above formula, examples of the substituent that the aromatic cyclic group may have include a halogen atom, an alkyl group, an alkoxy group, a halogenated alkyl group having 1 to 5 carbon atoms, an oxygen atom (=O), etc. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. aryl The substituent that the aromatic cyclic group may have is preferably a fluorine atom. A aryl The aromatic cyclic group may be unsubstituted or may have a substituent, and is preferably unsubstituted. A aryl In the above, when the aromatic cyclic group has a substituent, the number of the substituent may be one or two or more, preferably one or two, and more preferably one.

[0426] In the formula (f1-3), Lf 3 The divalent linking group having no polycyclic structure and no acid-labile group in 1 and Lf 3 is the same as the divalent linking group having no polycyclic structure and no acid-labile group in the above formula (I). Lf 3 Examples of the divalent linking group having no polycyclic structure and no acid-dissociable group include an alkylene group having 1 to 10 carbon atoms, -O-, -C(=O)-, -C(=O)-O-, -OC(=O)-, a carbonate bond (-OC(=O)-O-), -NH-C(=O)-, or a combination thereof, and a combination of -O- and an alkylene group having 1 to 10 carbon atoms is most preferred. Examples of alkylene groups having 1 to 10 carbon atoms include linear, branched, and cyclic alkylene groups, and linear or branched alkylene groups having 1 to 5 carbon atoms and cyclic alkylene groups having 4 to 10 carbon atoms are preferred.

[0427] Specific examples of the structural unit (f1) are shown below. In each of the following formulas, R α represents a hydrogen atom or a methyl group.

[0428] [ka]

[0429] Of these, the structural unit (f1) is preferably a structural unit represented by the above general formula (f1-1). The structural unit (f1) contained in the component (F1) may be of one type, or may be of two or more types. Within the component (F1), the proportion of the structural unit (f1) relative to the total (100 mol %) of all structural units constituting the component (F1) is preferably within a range from 35 to 100 mol %, more preferably from 55 to 90 mol %, and even more preferably from 60 to 85 mol %. By ensuring that the proportion of the structural unit (f1) is at least the lower limit of the above-mentioned preferred range, the surface segregation effect is enhanced, and affinity with the developer can be improved, which tends to improve lithography properties such as improved roughness. Furthermore, by ensuring that the proportion is at most the upper limit, a balance with other structural units can be achieved, which tends to improve various lithography properties.

[0430] Other structural units The component (F1) may contain other structural units in addition to the structural unit (f1) described above, as necessary. Examples of other structural units include structural units (f2) containing an acid-decomposable group whose polarity increases when acted upon by an acid, structural units (f3) represented by general formula (f3-1) described below, structural units (f4) containing a lactone-containing cyclic group (excluding those corresponding to structural unit (f1)), and structural units (f5) represented by general formula (f5-1) described below.

[0431] <Constituent unit (f2)> The structural unit (f2) is the same as the structural unit (a1) in the component (A1) described above. Of these, as the structural unit (f2), a structural unit having an acid-dissociable group represented by the above general formula (a1-r2-1) or (a1-r2-3) is preferred, and the structural unit (f2-11) represented by the following general formula (f2-1) is more preferred.

[0432] [ka] [wherein 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 between 0 and 2. 1 is an acid-dissociable group represented by general formula (a1-r2-1) or (a1-r2-3).

[0433] In the formula (f1-1), R and Va 1 represents R and Va in the formula (a1-1). 1 is the same as:

[0434] The structural unit (f2) contained in the component (F1) may be of one type, or may be of two or more types. The component (F1) may or may not contain the structural unit (f2), although it is preferable for the component (F1) to contain the structural unit (f2). When the component (F1) contains the structural unit (f2), the proportion of the structural unit (f2) in the component (F1) is preferably 5 to 50 mol %, more preferably 10 to 45 mol %, and even more preferably 15 to 40 mol %, based on the total (100 mol %) of all structural units constituting the component (F1). When the proportion of the structural unit (f2) is at least as large as the lower limit of the above-mentioned preferred range, the solubility of the exposed areas of the resist film in a developer is more easily promoted.When the proportion of the structural unit (f2) is at most the upper limit of the above-mentioned range, a balance with the other structural units can be achieved.

[0435] <Constituent unit (f3)> The structural unit (f3) is a structural unit represented by the following general formula (f3-1).

[0436] [ka] [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.]

[0437] In the general formula (f3-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms in R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. From the viewpoint of industrial availability, a hydrogen atom or a methyl group is more preferred, and a methyl group is even more preferred.

[0438] The structural unit (f3) contained in the component (F1) may be of one type, or may be of two or more types. The component (F1) may or may not contain the structural unit (f3), although it is preferable for the component (F1) to contain the structural unit (f3). When the component (F1) contains the structural unit (f3), the proportion of the structural unit (f3) in the component (F1) is preferably 1 to 25 mol %, more preferably 3 to 20 mol %, and even more preferably 5 to 15 mol %, based on the total (100 mol %) of all structural units constituting the component (F1). When the proportion of the structural unit (f3) is at least as large as the lower limit of the above-mentioned range, the solubility of the resist film in an alkaline developer during an alkaline development process is likely to be increased. Furthermore, the effect of suppressing the occurrence of defects is further improved. When the proportion of the structural unit (f3) is at most the upper limit of the above-mentioned range, a balance with the other structural units can be achieved.

[0439] <Constituent unit (f4)> The structural unit (f4) containing a lactone-containing cyclic group is the same as the structural unit (a2) containing a lactone-containing cyclic group within the component (A1) described above. Of these, as the structural unit (f4), a structural unit having a lactone-containing cyclic group represented by the above general formula (a2-r-1) or (a2-r-2) is preferred, and the structural unit (f4-1) represented by the following general formula (f4-1) is more preferred.

[0440] [ka] [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.] 21 is a single bond or a divalent linking group. 21 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, where R' represents a hydrogen atom or a methyl group. 21 If -O-, Ya 21 does not become -CO-. Raf 21 is a lactone-containing cyclic group represented by the general formula (a2-r-1) or (a2-r-2).

[0441] In the formula (f4-1), R, Ya 21 , La 21 and R' are R, Ya in the formula (a2-1). 21 , La 21 and R'.

[0442] The structural unit (f4) contained in the component (F1) may be of one type, or may be of two or more types. The component (F1) may or may not contain the structural unit (f4), although it is preferable for it to contain the structural unit (f4). When the component (F1) contains the structural unit (f4), the proportion of the structural unit (f4) in the component (F1) is preferably 5 to 50 mol %, more preferably 10 to 45 mol %, and even more preferably 15 to 40 mol %, relative to the total (100 mol %) of all structural units constituting the component (F1). When the proportion of the structural unit (f4) is at least as large as the lower limit of the above-mentioned range, the solubility of the resist film in an alkaline developer during an alkaline development process is likely to be increased. This is also effective in reducing defects. When the proportion of the structural unit (f4) is no greater than the upper limit of the above-mentioned range, it is easier to achieve a good balance with other structural units.

[0443] <Constituent Unit (f5)> The structural unit (f5) is a structural unit represented by the following general formula (f5-1).

[0444] [ka] [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 Rf may form a condensed ring. 51 Rf is a fluorinated alkyl group having 1 to 12 carbon atoms. 52 is a hydrogen atom or an organic group having 1 to 12 carbon atoms which may have a fluorine atom. ax2 is an integer between 1 and 3.

[0445] In the general formula (f5-1), W 2 and Ya x2 represents W in the general formula (a8-1). 2 and Ya x2 is the same as: In the general formula (f5-1), Rf 51 The fluorinated alkyl group having 1 to 12 carbon atoms in the formula (a8-1) is R 1 The same applies to the fluorinated alkyl group having 1 to 12 carbon atoms in the above. In the general formula (f5-1), Rf 52 The organic group having 1 to 12 carbon atoms which may have a fluorine atom is R 2 The same applies to the organic group having 1 to 12 carbon atoms which may have a fluorine atom in the above formula.

[0446] Preferred examples of the component (F1) include a polymer (homopolymer) composed of the structural unit (f1), a copolymer (F1-a) having a repeating structure of the structural unit (f1) and the structural unit (f2), a copolymer (F1-b) having a repeating structure of the structural unit (f1), the structural unit (f2), and the structural unit (f3), a copolymer (F1-c) having a repeating structure of the structural unit (f1) and the structural unit (f4), and a copolymer (F1-d) having a repeating structure of the structural unit (f1) and the structural unit (f5).

[0447] In the copolymer (F1-a), the proportion of the structural unit (f1) is preferably 55 to 85 mol %, more preferably 60 to 80 mol %, and even more preferably 65 to 75 mol %, relative to the total (100 mol %) of all structural units constituting the copolymer (F1-a). In the copolymer (F1-a), the proportion of the structural unit (f2) relative to the total (100 mol%) of all structural units constituting the copolymer (F1-a) is preferably 15 to 45 mol%, more preferably 20 to 40 mol%, and even more preferably 25 to 35 mol%.

[0448] In the copolymer (F1-b), the proportion of the structural unit (f1) relative to the total (100 mol%) of all structural units constituting the copolymer (F1-b) is preferably 55 to 85 mol%, more preferably 60 to 80 mol%, and even more preferably 65 to 75 mol%. In the copolymer (F1-b), the proportion of the structural unit (f2) is preferably 5 to 35 mol %, more preferably 10 to 30 mol %, and even more preferably 15 to 25 mol %, relative to the total (100 mol %) of all structural units constituting the copolymer (F1-b). In the copolymer (F1-b), the proportion of the structural unit (f3) is preferably 1 to 25 mol %, more preferably 3 to 20 mol %, and even more preferably 5 to 15 mol %, relative to the total (100 mol %) of all structural units constituting the copolymer (F1-b).

[0449] In the copolymer (F1-c), the proportion of the structural unit (f1) relative to the total (100 mol%) of all structural units constituting the copolymer (F1-c) is preferably 55 to 85 mol%, more preferably 60 to 80 mol%, and even more preferably 65 to 75 mol%. In the copolymer (F1-c), the proportion of the structural unit (f4) relative to the total (100 mol%) of all structural units constituting the copolymer (F1-c) is preferably 15 to 45 mol%, more preferably 20 to 40 mol%, and even more preferably 25 to 35 mol%.

[0450] In the copolymer (F1-d), the proportion of the structural unit (f1) relative to the total (100 mol%) of all structural units constituting the copolymer (F1-d) is preferably 55 to 85 mol%, more preferably 60 to 80 mol%, and even more preferably 65 to 75 mol%. In the copolymer (F1-d), the proportion of the structural unit (f5) is preferably 15 to 45 mol %, more preferably 20 to 40 mol %, and even more preferably 25 to 35 mol %, relative to the total (100 mol %) of all structural units constituting the copolymer (F1-d).

[0451] The component (F1) can be obtained by polymerizing a monomer that derives the desired structural unit by known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate.

[0452] The weight-average molecular weight (Mw) of component (F1) (based on polystyrene standards measured by gel permeation chromatography) is preferably 1000 to 50000, more preferably 5000 to 40000, and even more preferably 10000 to 30000. When the Mw is below the upper limit of this range, the compound 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 compound has good dry etching resistance and the cross-sectional shape of the resist pattern.

[0453] The dispersity (Mw / Mn) of the component (F1) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and even more preferably from 1.2 to 2.5.

[0454] In the resist composition of this embodiment, as the component (F1), one type of compound may be used, or two or more types may be used in combination. The resist composition of this embodiment may also contain, as the component (F), a fluorine additive component that is decomposable in an alkaline developer and does not fall under the category of the component (F1). The proportion of component (F1) within component (F), relative to the total mass of component (F), 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 the proportion of component (F1) is 25 mass% or more, it becomes easier to improve the contrast between exposed and unexposed areas of the resist film when forming a resist pattern.

[0455] In the resist composition of this embodiment, the component (F) may be used alone, or in combination of two or more different compounds. In the resist composition of this embodiment, the amount of the component (F) relative to 100 parts by mass of the component (A) is preferably 0.5 to 15 parts by mass, more preferably 1 to 12 parts by mass, and even more preferably 2 to 10 parts by mass. When the content of component (F) is at least the lower limit of the above range, the solubility of the unexposed areas of the resist film in an alkaline developer is easily increased during resist pattern formation, resulting in improved resolution and suppressed defect formation. On the other hand, when the content is at most the upper limit, improved lithography properties are achieved.

[0456] In this embodiment, the component (F) may contain a group represented by the above general formula (np1), (np2), or (np3) from the viewpoint of decomposability. In this embodiment, from the viewpoint of reducing the burden on the environment, it is preferable that the component (F) does not contain a trifluoromethyl group or a difluoromethylene group, and 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 In the above formula, it is preferable that Rpf does not contain a structure represented by the formula -. 1 ~Rpf 3are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0457] In this embodiment, from the standpoint of reducing the burden on the environment, the component (F1) may contain, as the structural unit (f1), at least one structural unit selected from the group consisting of a structural unit (f1-11) represented by the following general formula (f1-11), a structural unit (f1-21) represented by the following general formula (f1-21), and a structural unit (f1-31) represented by the following general formula (f1-31):

[0458] [ka] [wherein R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Lf 11 and Lf 21 are each independently a divalent linking group not containing an acid-labile group; Rf 11 and Rf 31 are each independently an organic group having a fluorine atom; Rf 21 is a monovalent organic group, provided that Lf 21 and Rf 21 at least one of A is a group in which some or all of the hydrogen atoms are substituted with fluorine atoms; arylx is a divalent aromatic hydrocarbon group which may have a substituent; Lf 31 is a divalent linking group that does not have a single bond or a polycyclic structure and does not contain an acid-labile group. 11 , Rf 11 , Lf 21 , Rf 21 , A arylx , Lf 31 and Rf 31 is the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 - does not include structures represented by the formula:

[0459] In the formulae (f1-11), (f1-21) and (f1-31), R is the same as R in the formulae (f1-1), (f1-2) and (f1-3). In the formulas (f1-11) and (f1-21), Lf 11 and Lf 21 is Lf in the formulas (f1-1) and (f1-2). 1 and Lf 2 is the same as: In the formulae (f1-11) and (f1-31), Rf 11 and Rf 31 represents Rf in the formulas (f1-1) and (f1-3). 1 and Rf 3 is the same as: In the formula (f1-21), Rf 21 is Rf in the formula (f1-2). 2 is the same as: In the formula (f1-31), A arylx is A in the formula (f1-3). aryl is the same as: In the formula (f1-31), Lf 31 is Lf in the formula (f1-3). 3 is the same as: However, R, Lf 11 , Rf 11 , Lf 21 , Rf 21 , A arylx , Lf 31 and Rf 31 is the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 - does not include structures represented by

[0460] In the formulas (f1-11), (f1-21) and (f1-31), the formula -Rpf 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 The structure represented by - preferably does not contain a trifluoromethyl group or a difluoromethylene group, and preferably excludes the groups represented by the general formula (np1), (np2) or (np3).

[0461] The structural unit (f1-11) is preferably a structural unit represented by the following general formula (f1-11-1).

[0462] [ka] [Wherein, Lf 111 Rf is a linear or branched alkylene group having 1 to 5 carbon atoms. 111 represents an alkyl group having 1 to 5 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms, which may have a nitro group as a substituent.]

[0463] In the formula (f1-11-1), Lf 111 is preferably a methylene group having 1 to 1 carbon atoms. 111 is preferably —CH2—NO2, a methyl group or a cyclohexyl group.

[0464] <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, PGMEA, PGME, γ-butyrolactone, EL, cyclohexanone, and diacetone alcohol are preferred.

[0465] Furthermore, a mixed solvent of PGMEA and a polar solvent is also preferred as component (S), and the blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and the polar solvent, etc. The component (S) is also preferably a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone, in which case the mass ratio of the former to the latter is preferably 70:30 to 95:5. There are no particular restrictions on the amount of component (S) used, and it is set appropriately depending on the coating film thickness so as to provide a concentration that allows application to a substrate, etc. Generally, the component (S) is used so that the solids concentration of the resist composition falls within the range of 0.1 to 20 mass %, and preferably 0.2 to 15 mass %.

[0466] In this embodiment, the component (S) may contain a group represented by the above general formula (np1), (np2), or (np3) from the viewpoint of decomposability. In this embodiment, from the viewpoint of reducing the burden on the environment, it is preferable that the component (S) does not contain a trifluoromethyl group or a difluoromethylene group, and 1 -CF3 and the structure represented by the formula -Rpf 2 -CF2-Rpf 3 In the above formula, it is preferable that Rpf does not contain a structure represented by the formula -. 1 ~Rpf 3 are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

[0467] The resist composition of this embodiment may be prepared by dissolving the resist material in component (S) and then removing impurities 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 such polyimide porous films and polyamideimide porous films include those described in JP 2016-155121 A.

[0468] The resist composition of this embodiment described above uses the compound (B0) and the fluororesin component (F1) in combination, making it possible to form a resist pattern that maintains good sensitivity, has good lithography properties such as low roughness, and has reduced pattern defects. Compound (B0) has a bulky structure due to the presence of an aromatic ring containing a fluorine atom as a substituent between the cyclic group and the sulfonic acid group. It is presumed that such a bulky structure provides sufficient acid strength and improves lithography properties. Furthermore, since the carbon atom adjacent to the sulfonic acid group of compound (B0) is not fluorinated, it is considered that there is a low risk of it being subject to future restrictions on its use and production. On the other hand, compound (B0) may have a structure that is more hydrophobic than conventional acid generators in which the adjacent carbon atom of a sulfonic acid is fluorinated. By combining compound (B0) with a fluororesin component (F1), the resist composition of this embodiment improves the hydrophilicity of the resist composition and improves its solubility in a developer, which is presumed to contribute to improving lithography properties such as CDU and reducing defects. It is presumed that the combined effects described above enable the resist composition of this embodiment to form a resist pattern that maintains good sensitivity, has good lithography properties such as roughness, and has reduced pattern defects.

[0469] (Method for forming a resist pattern) A method for forming a resist pattern according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition according to the first aspect of the present invention, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. One embodiment of the resist pattern forming method is, for example, a resist pattern forming method carried out as follows.

[0470] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and then baked (post-apply bake (PAB)) at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an ArF exposure device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with an electron beam without using a mask pattern, and 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 using an alkaline developer in the case of an alkaline development process, or a developer containing an organic solvent (organic developer) in the case of a solvent development process.

[0471] After the development process, a rinse process is preferably carried out. In the case of an alkaline development process, the rinse process is preferably a water rinse using pure water, and in the case of a solvent development process, it is preferable to use a rinse solution containing an organic solvent. In the case of a solvent development process, the developing treatment or rinsing treatment may be followed by a treatment of removing the developing solution or rinsing solution adhering to the pattern using a supercritical fluid. After the development treatment or rinsing treatment, the film is dried. In some cases, a baking treatment (post-baking) may be performed after the development treatment.

[0472] 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.

[0473] The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays can be used. The method for 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.

[0474] The exposure method for the resist film may be a normal exposure (dry exposure) carried out in air or an inert gas such as nitrogen, or may be liquid immersion lithography. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure device is filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. The immersion medium is preferably a solvent having a refractive index greater than that of air and less than that of the resist film to be exposed, such as water, a fluorine-based inert liquid, a silicon-based solvent, or a hydrocarbon-based solvent. As the immersion medium, water is preferably used.

[0475] The alkaline developer used in the development treatment in the alkaline development process may be, for example, a 0.1 to 10 mass % aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent capable of dissolving component (A) (component (A) before exposure), and may be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0476] 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.

[0477] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0478] 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.

[0479] 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).

[0480] The organic solvent contained in the rinse solution used in the rinsing treatment after development in the solvent development process can be selected appropriately from the organic solvents listed above as organic solvents used in the organic developer, so long as it does 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 of two or more, and may be used in combination with other organic solvents or water.

[0481] 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).

[0482] According to the method of forming a resist pattern of the present embodiment as described above, the resist composition described above is used, so it is possible to form a resist pattern that maintains good sensitivity, has good lithography properties such as roughness, and has reduced pattern defects.

[0483] The resist composition of the above-described embodiment and the various materials used in the pattern formation method of the above-described embodiment (e.g., resist solvent, developer, rinse, anti-reflective coating composition, top coat composition, etc.) preferably do not contain impurities such as metals, halogen-containing metal salts, acids, alkalis, or components containing sulfur or phosphorus atoms. Examples of metal-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, and salts thereof. The content of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device). [Example]

[0484] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0485] (Synthesis Example 1: Synthesis of compound (fm-17)) Under a nitrogen atmosphere, 4.0 g of compound (X1), 3.0 g of compound (Y1), 0.03 g of dimethylaminopyridine, and 15 g of dichloromethane were placed in a three-neck flask and stirred at 10°C or below. 2.9 g of diisopropylcarbodiimide was added while maintaining the temperature, and the mixture was stirred at 10°C or below for 0.5 hours. The temperature was then raised to 25°C and the mixture was stirred for 12 hours. The reaction mixture was then filtered, and the filtrate was washed three times with 100 g of 1% aqueous citric acid solution, followed by three times with 100 g of purified water. After washing, the mixture was concentrated to dryness using a rotary pump, yielding 4.5 g of compound (fm-17) as a white solid (yield 60%).

[0486] [ka]

[0487] The obtained compound (fm-17) was subjected to NMR measurement, and its structure was identified from the following results.

[0488] 1 H-NMR:δ 1.35(3H,d,J=7.1Hz),1.86(3H,s),4.80(2H,s),5.30(1H,q,J=7.1Hz),5.56(1H,d,J=3.8Hz),6.06(1H,d,J=3.8Hz)

[0489] (Synthesis Example 2: Synthesis of compound (fm-16)) Compound (fm-16) was obtained in the same manner as in Synthesis Example 1, except that compound (X1) was changed to compound (X2).

[0490] [ka]

[0491] The obtained compound (fm-16) was subjected to NMR measurement, and its structure was identified from the following results.

[0492] 1 H-NMR:δ 1.86(3H,s),3.60(2H,d,J=5.6Hz),4.78(2H,s),5.41(1H,t,J=5.6Hz),5.56(1H,d,J=3.8Hz),6.06(1H,d,J=3.8Hz)

[0493] (Synthesis Example 3: Synthesis of compound (fm-18)) Compound (fm-18) was obtained in the same manner as in Synthesis Example 1, except that compound (X1) was changed to compound (X3).

[0494] [ka]

[0495] The obtained compound (fm-18) was subjected to NMR measurement, and its structure was identified from the following results.

[0496] 1H-NMR:δ 1.26-1.66(10H,1.33(dtt,J=12.1,6.5,2.8Hz),1.47(dtt,J=12.8,6.5,2.8Hz),1.58(dtd,J=13.4,6.5,2.8Hz)),1.86(3 H,s),2.24(1H,tdt,J=10.3,3.0,2.8Hz),4.82(2H,s),5.10(1H,d,J=3.0Hz),5.56(1H,d,J=3.8Hz),6.06(1H,d,J=3.8Hz)

[0497] <Preparation of Resist Composition> (Examples 1 to 28, Comparative Examples 1 to 10) The components shown in Tables 1 to 3 were mixed and dissolved to prepare the resist compositions of the respective examples.

[0498] [Table 1]

[0499] [Table 2]

[0500] [Table 3]

[0501] In Tables 1 to 3, the abbreviations have the following meanings. The values ​​in brackets [ ] are the blend amounts (parts by mass). The weight-average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) of the polymer compounds were determined by GPC measurement (standard polystyrene equivalent). The copolymer composition ratio of the polymer compounds (the proportion (molar ratio) of each structural unit in the structural formula) was determined by carbon-13 nuclear magnetic resonance spectroscopy (600 MHz, 13 C-NMR).

[0502] (A1)-1: The following polymer compound (A1-1): Weight average molecular weight (Mw) 5,800, molecular weight dispersity (Mw / Mn) 1.54, m / n = 50 / 50. (A1)-2: The following polymer compound (A1-2): Weight average molecular weight (Mw) 6000, molecular weight dispersity (Mw / Mn) 1.55, m / n = 50 / 50. (A1)-3: The following polymer compound (A1-3): Weight average molecular weight (Mw) 5900, molecular weight dispersity (Mw / Mn) 1.54, m / n = 50 / 50.

[0503] [ka]

[0504] (B0)-1 to (B0)-8: Acid generators comprising the above compounds (B0-1) to (B0-18). (B1)-1: An acid generator comprising the following compound (B1-1):

[0505] [ka]

[0506] (D1)-1 to (D1)-2: Acid diffusion controllers consisting of compounds represented by the following chemical formulas (D1-1) to (D1-2).

[0507] [ka]

[0508] (F1)-1: A polymer compound represented by the following formula (F1-1). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F0)-2: A polymer compound represented by the following formula (F1-2). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m / n = 70 / 20 / 10. (F1)-3: A polymer compound represented by the following formula (F1-3). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m / n = 70 / 20 / 10. (F1)-4: A polymer compound represented by the following formula (F1-4). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-5: A polymer compound represented by the following formula (F1-5). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-6: Polymer compound represented by the following formula (F1-6). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30.

[0509] [ka]

[0510] (F1)-7: A polymer compound represented by the following formula (F1-7). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-8: Polymer compound represented by the following formula (F1-8). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-9: A polymer compound represented by the following formula (F1-9). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-10: A polymer compound represented by the following formula (F1-10). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-11: Homopolymer represented by the following formula (F1-11). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. (F1)-12: A polymer compound represented by the following formula (F1-12). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-13: A polymer compound represented by the following formula (F1-13). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-14: A polymer compound represented by the following formula (F1-14). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70.13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-15: A polymer compound represented by the following formula (F1-15). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30.

[0511] [ka]

[0512] (F1)-16: A polymer compound represented by the following formula (F1-16). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-17: A polymer compound represented by the following formula (F1-17). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30. (F1)-18: Polymer compound represented by the following formula (F1-18). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m / n = 70 / 20 / 10.

[0513] [ka]

[0514] (F2)-1: A polymer compound represented by the following formula (F2-1). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 15,000, and the molecular weight dispersity (Mw / Mn) is 1.70. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 70 / 30.

[0515] [ka]

[0516] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / ethyl lactate / diacetone alcohol = 45 / 25 / 15 / 15 (mass ratio).

[0517] <Formation of Resist Pattern> Each resist composition of each example was applied using a spinner onto a 12-inch silicon substrate that had been treated with hexamethyldisilazane (HMDS), and then pre-baked (PAB) on a hot plate at 110°C for 60 seconds, followed by drying to form a resist film with a thickness of 50 nm. Next, the resist film was exposed to light using an EUV scanner NXE3400 (NXE3400 (NA 0.33, inner σ / outer σ=0.3 / 0.9, quadrupole illumination, manufactured by ASML) (manufactured by ASML) to form a contact hole pattern (hereinafter referred to as a "CH pattern") in which holes with a diameter of 26 nm were arranged at equal intervals (pitch of 52 nm), and then subjected to a post-exposure bake (PEB) treatment at 110°C for 60 seconds. Next, alkaline development was performed for 30 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C, followed by a water rinse treatment with pure water for 15 seconds. As a result, a CH pattern was formed in which holes with a diameter of 26 nm were arranged at equal intervals (pitch of 52 nm).

[0518] [Evaluation of optimal exposure (Eop)] The optimum exposure dose Eop (mJ / cm) for forming a CH pattern of the target size by the above resist pattern forming method. 2 The results are shown in Tables 4 to 6.

[0519] [Evaluation of Pattern Dimension Uniformity (CDU)] For the CH patterns formed by the "Formation of Resist Patterns" above, a total of 10,000 CH patterns were observed from above using a length-measuring SEM (scanning electron microscope, accelerating voltage 500V, product name: CG6300, manufactured by Hitachi High-Technologies Corporation), and the hole diameter (nm) of each hole was measured. Then, triple the standard deviation (σ) calculated from the measurement results (3σ) was calculated. The results are shown in Tables 4 to 6 as "CDU (nm)." The smaller the value of 3σ thus determined, the higher the dimensional (CD) uniformity of the plurality of holes formed in the resist film.

[0520] [Evaluation of pattern defects] Of the 10,000 CH patterns observed in the "Evaluation of the Intra-Wafer Uniformity (CDU) of Pattern Dimensions" above, defects with a hole diameter of 18.2 nm (70% of the target size) or less were defined as insufficient opening defects, and the number of such defects was counted. The results are shown in Tables 4 to 6.

[0521] [Table 4]

[0522] [Table 5]

[0523] [Table 6]

[0524] The results shown in Tables 4 to 6 confirm that the resist compositions of the examples had good sensitivity and CDU, and reduced the number of pattern defects.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, a resin component (A1) whose solubility in a developer changes under the action of an acid; an acid generator component (B) that generates an acid upon exposure to light; and a fluororesin component (F1) having a structural unit (f1) containing a base dissociable group, The acid generator component (B) contains a compound (B0) represented by the following general formula (b0): The resist composition includes the structural unit (f1) containing a base dissociable group, which includes at least one structural unit selected from the group consisting of a structural unit (f1-1) represented by the following general formula (f1-1), a structural unit (f1-2) represented by the following general formula (f1-2), and a structural unit (f1-3) represented by the following general formula (f1-3): 【Chemistry 1】 [In the formula, Ar represents an aromatic ring. ０ represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. ０ is -C(=O)-O-, -O-C(=O)- or -O-S(=O) ２ represents a divalent linking group containing -. ０ represents a cyclic group. ０ represents an organic group. n01 is an integer of 1 or more as long as the valence allows. n02 is an integer of 0 or more as long as the valence allows. ０ -Yb ０ is -O-C(=O)-Yb ０ If Yb ０ is an alicyclic group which may have a substituent, a fused ring group of an aliphatic ring and an aromatic ring which may have a substituent, or an aromatic hydrocarbon group which has a substituent, and in the aromatic hydrocarbon group, at least one hydrogen atom of the aromatic ring is substituted with an alkyl group or an alkoxy group. ０ may be the same or different. When n02 is 2 or more, a plurality of Rb ０ may be the same or different, m is an integer of 1 or more, and M ｍ＋ represents an m-valent cation, where Rf ０ , L ０ , Yb ０ , Rb ０ and M ｍ＋ is the formula -Rpf １ -CF ３ The structure and formula -Rpf ２ -CF ２ -Rpf ３ The structure represented by - is not included. １ ~Rpf ３ are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent. 【Chemistry 2】 [wherein each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Lf １ and Lf ２ are each independently a divalent linking group not containing an acid-labile group; Rf １ and Rf ３ each independently represents an organic group having a fluorine atom; Rf ２ is a monovalent organic group, provided that Lf ２ and Rf ２ at least one of A is a group in which some or all of the hydrogen atoms have been substituted with fluorine atoms; ａｒｙｌ represents a divalent aromatic hydrocarbon group which may have a substituent; Lf ３ is a divalent linking group that does not have a single bond or a polycyclic structure and does not contain an acid-dissociable group.

2. 2. The resist composition according to claim 1, wherein the compound (B0) is a compound represented by the following general formula (b0-1): 【Transformation 3】 [wherein, Rf ０１ represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. ０１ is -C(=O)-O-, -O-C(=O)- or -O-S(=O) ２ represents a divalent linking group containing -. ０１ represents a cyclic group. ０１ represents an organic group, n011 is an integer of 1 or more, n021 is an integer of 0 or more, and n011 + n022 ≦ 4. ０１ -Yb ０１ is -O-C(=O)-Yb ０１ If Yb ０１ is an alicyclic group which may have a substituent, a fused cyclic group of an aliphatic ring and an aromatic ring which may have a substituent, or an aromatic hydrocarbon group which has a substituent, and in the aromatic hydrocarbon group, at least one hydrogen atom of the aromatic ring is substituted with an alkyl group or an alkoxy group. ０１ may be the same or different. When n021 is 2 or more, a plurality of Rb ０１ may be the same or different, m is an integer of 1 or more, and M ｍ＋ represents an m-valent cation, where Rf ０１ , L ０１ , Yb ０１ , Rb ０１ and M ｍ＋ is the formula -Rpf １ -CF ３ The structure and formula -Rpf ２ -CF ２ -Rpf ３ The structure represented by - is not included. １ ~Rpf ３ are each independently a single bond or a hydrocarbon group which may have a fluorine atom as a substituent.

3. 2. The resist composition according to claim 1, wherein the fluororesin component (F1) comprises a structural unit (f1) containing the base dissociable group and a structural unit (f2) containing an acid-decomposable group whose polarity increases upon the action of an acid.

4. 2. The resist composition according to claim 1, wherein the fluororesin component (F1) comprises a structural unit (f1) containing the base dissociable group and a structural unit (f3) represented by the following general formula (f3-1): 【Transformation 5】 [wherein 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.]

5. 2. The resist composition according to claim 1, wherein the fluororesin component (F1) comprises a structural unit (f1) containing the base dissociable group and a structural unit (f4) containing a lactone-containing cyclic group.

6. 2. The resist composition according to claim 1, wherein the fluororesin component (F1) has a structural unit (f1) containing the base dissociable group and a structural unit derived from a compound represented by the following general formula (f5-1): 【Transformation 6】 [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. ５１ is a fluorinated alkyl group having 1 to 12 carbon atoms. ５２ is a hydrogen atom or an organic group having 1 to 12 carbon atoms which may have a fluorine atom. ａｘ２ is an integer from 1 to 3.

7. 10. 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.

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