Resist composition, method for forming resist pattern, compound and acid diffusion controller

Abstract

To provide a resist composition that can form a resist pattern having excellent CDU and resolution.SOLUTION: A resist composition contains a base component (A) and a compound (D0) represented by general formula (d0), where Rd0 is a condensed cyclic group that contains a condensed ring containing one or more aromatic rings. The condensed cyclic group has, as a substituent, an acid-degradable group that is degraded by the action of an acid to form a polar group. Yd0 is a divalent linking group or a single bond. Mm+ is an m-valent organic cation. m is an integer of 1 or greater.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resist composition, a method of forming a resist pattern, a compound, and an acid diffusion controller. [Background technology]

[0002] In recent years, advances in lithography technology have led to rapid progress in miniaturization of patterns in the manufacture of semiconductor devices and liquid crystal display devices. A common method of miniaturization is to use shorter wavelengths (higher energy) exposure light sources.

[0003] Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist composition that 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, has been used so far.

[0004] In forming a resist pattern, the behavior of the acid generated from an acid generator component upon exposure is considered to be one factor that greatly influences the lithography properties. In response to this, a chemically amplified resist composition has been proposed which contains, in addition to an acid generator component, an acid diffusion controller that controls the diffusion of the acid generated from the acid generator component upon exposure. For example, Patent Document 1 discloses an acid generator and an acid diffusion controller in which the anion moiety has a specific bulky structure (bicyclooctane skeleton) mainly composed of hydrocarbon and has relatively enhanced hydrophobicity. The invention described in Patent Document 1 mainly employs a compound having an anion moiety with relatively enhanced hydrophobicity as an acid generator, and discloses that a resist composition containing the compound can achieve high sensitivity in resist pattern formation and can form a resist pattern with high resolution and reduced roughness and a good shape. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-92159 A Summary of the Invention [Problem to be solved by the invention]

[0006] As lithography technology continues to advance and resist patterns become finer, for example, in EUV and EB lithography, the goal is to form fine patterns of several tens of nm. As resist pattern dimensions become smaller, there is a demand for resist compositions that can form resist patterns with good within-plane uniformity (CDU) and resolution of the pattern dimensions. However, in a resist composition containing an acid diffusion controller having a bulky structure as described in Patent Document 1 as described above, although the uniformity of the acid diffusion controller in the resist film can be increased by improving the hydrophobicity, the affinity for the developer is reduced, and there is room for improvement in terms of achieving both CDU and resolution.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a CDU, and a resist composition capable of forming a resist pattern with excellent resolution, a method of forming a resist pattern using the resist composition, a novel compound that is useful as an acid generator for the resist composition, and an acid generator using the compound. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration. That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; an acid generator component (B) that generates an acid upon exposure; and an acid diffusion controller component (D) that controls the diffusion of the acid generated from the acid generator component (B) upon exposure, wherein the acid diffusion controller component (D) contains a compound (D0) represented by the following general formula (d0):

[0009] [ka] [In the formula, Rd 0 is a fused ring group containing one or more fused rings each having an aromatic ring. The fused ring group has, as a substituent, an acid-decomposable group that is decomposed by the action of an acid to generate a polar group. 0 is a divalent linking group or a single bond. m+ represents an organic cation having a valence of m, where m is an integer of 1 or more.

[0010] A second aspect of the present invention is a method for forming a resist pattern, comprising the steps of forming a resist film on a support using the resist composition related to the first aspect, exposing the resist film to light, and developing the exposed resist film to form a resist pattern.

[0011] A third aspect of the present invention is a compound represented by the following general formula (d0):

[0012] [ka] [In the formula, Rd 0 is a fused ring group containing one or more fused rings each having an aromatic ring. The fused ring group has, as a substituent, an acid-decomposable group that is decomposed by the action of an acid to generate a polar group. 0 is a divalent linking group or a single bond. m+ represents an organic cation having a valence of m, where m is an integer of 1 or more.

[0013] A fourth aspect of the present invention is an acid diffusion controller comprising the compound according to the third aspect. Effect of the Invention

[0014] According to the present invention, it is possible to provide a CDU, and a resist composition capable of forming a resist pattern with excellent resolution, a method of forming a resist pattern using the resist composition, a novel compound that is useful as an acid generator for the resist composition, and an acid generator using the compound. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In this specification and claims, the term "aliphatic" is a relative concept to aromaticity and is defined as meaning a group, compound, etc. that does not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in an alkoxy group. 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 intended to include any concept including irradiation with radiation.

[0016] The term "acid-decomposable group" refers to a group having acid decomposability in which at least a part 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 are decomposed by the action of an acid to generate a polar group. Examples of the polar group 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).

[0017] The term "acid dissociable group" refers to both (i) a group having acid dissociability in which 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, and (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, and thus, when the acid dissociable group is dissociated by the action of an acid, a polar group with higher polarity than the acid dissociable group is generated, increasing the polarity. As a result, the polarity of the entire (A1) component increases. The increase in polarity relatively changes the solubility in the developer, increasing the solubility when the developer is an alkaline developer, and decreasing the solubility when the developer is an organic developer.

[0018] The "base material component" is an organic compound having a film-forming ability. Organic compounds used as base material components are broadly divided into non-polymers and polymers. As non-polymers, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the term "low molecular weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4000. As polymers, those having a molecular weight of 1000 or more are usually used. Hereinafter, the terms "resin", "polymer compound" and "polymer" refer to a polymer having a molecular weight of 1000 or more. The molecular weight of the polymer is the weight average molecular weight calculated in terms of polystyrene by GPC (gel permeation chromatography).

[0019] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. In the "acrylic acid ester", the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. αx ) is an atom or group other than a hydrogen atom. αx Itaconic acid diesters in which the substituent (R αx It also includes α-hydroxyacrylic esters in which the α-position carbon atom of an acrylic ester is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group of the acrylic ester. Unless otherwise specified, the carbon atom at the α-position 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 will sometimes be referred to as an α-substituted acrylic ester.

[0020] The term "derivative" refers to a concept that includes compounds in which the hydrogen atom at the α-position of the target compound is replaced with other substituents 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 the hydroxyl group of a target compound, which may have the hydrogen atom at the α-position replaced with a substituent, is replaced with an organic group; compounds in which the hydrogen atom at the α-position of a target compound, which may have the hydrogen atom at the α-position replaced with a substituent, is bonded with a substituent other than a hydroxyl group, and the like. The α-position refers to the first carbon atom adjacent to the functional group, unless otherwise specified. The substituent that replaces the hydrogen atom at the α-position of hydroxystyrene is R αx The same can be mentioned.

[0021] In the present specification and claims, some structures represented by chemical formulas may have asymmetric carbons, and may have enantiomers or diastereomers. In such cases, a single chemical formula represents all of the isomers. These isomers may be used alone or as a mixture.

[0022] (Resist composition) The resist composition of this embodiment generates an acid upon exposure, and the solubility of the resist composition in a developer changes due to the action of the acid. Such a resist composition contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of an acid, an acid generator component (B) (hereinafter also referred to as "component (B)") that generates an acid upon exposure, and an acid diffusion controller component (D) (hereinafter also referred to as "component (D)") that controls the diffusion of the acid generated from component (B) upon exposure.

[0023] When a resist film is formed using the resist composition of this embodiment and the resist film is selectively exposed, an acid is generated from the component (B) in the exposed portion of the resist film, and the solubility of the component (A) in the developer changes due to the action of the acid, whereas the solubility of the component (A) in the developer does not change in the unexposed portion of the resist film, resulting in a difference in solubility in the developer between the exposed portion and the unexposed portion. Therefore, when the resist film is developed, if the resist composition is a positive type, the exposed portion of the resist film is dissolved and removed to form a positive type resist pattern, and if the resist composition is a negative type, the unexposed portion of the resist film is dissolved and removed to form a negative type resist pattern.

[0024] In this specification, a resist composition that dissolves and removes an exposed portion of a resist film to form a positive resist pattern is referred to as a positive resist composition, and a resist composition that dissolves and removes an unexposed portion of a resist film to form a negative resist pattern is referred to as a negative resist composition. The resist composition of this embodiment may be a positive resist composition or a negative resist composition. In addition, the resist composition of this embodiment may be for an alkaline development process in which an alkaline developer is used for the development treatment when forming a resist pattern, or may be for a solvent development process in which a developer containing an organic solvent (organic developer) is used for the development treatment.

[0025] <Component (A)> In the resist composition of this embodiment, the component (A) preferably contains a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes under the action of an acid. By using the component (A1), the polarity of the base component changes before and after exposure, so that good development contrast can be obtained not only in an alkaline development process but also in a solvent development process. As the component (A), other polymeric compounds and / or low molecular weight compounds may be used in combination with the component (A1).

[0026] When an alkaline development process is applied, the base material component containing the component (A1) is poorly soluble in an alkaline developer before exposure, and when an acid is generated from the component (B) by exposure, for example, the polarity increases due to the action of the acid, and the solubility in an alkaline developer increases. Therefore, in forming a resist pattern, when a resist film obtained by applying the resist composition on a support is selectively exposed, the exposed part of the resist film changes from poorly soluble in an alkaline developer to soluble, while the unexposed part of the resist film remains poorly soluble in an alkaline developer, and a positive resist pattern is formed by alkaline development.

[0027] On the other hand, when a solvent development process is applied, the base material component containing the component (A1) is highly soluble in an organic developer before exposure, and when an acid is generated from the component (B) by exposure, for example, the acid increases the polarity and reduces the solubility in an organic developer. Therefore, when a resist film obtained by applying the resist composition to a support is selectively exposed in the formation of a resist pattern, the exposed part of the resist film changes from soluble to poorly soluble in an organic developer, while the unexposed part of the resist film remains soluble, and thus a contrast can be created between the exposed part and the unexposed part by developing with an organic developer, forming a negative resist pattern.

[0028] In the resist composition of this embodiment, the component (A) may use either a single type, or a combination of two or more types.

[0029] Regarding 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 contains an acid-decomposable group whose polarity increases when acted on by an acid. The component (A1) may contain other structural units in addition to the structural unit (a1), as necessary.

[0030] <Structural unit (a1)> The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases when acted upon by an acid.

[0031] Examples of the acid-dissociable group include those that have been proposed as acid-dissociable groups in base resins for chemically amplified resist compositions. Specific examples of the acid dissociable group that have been proposed for the base resin of the chemically amplified resist composition include the “acetal type acid dissociable group,” “tertiary alkyl ester type acid dissociable group,” and “tertiary alkyloxycarbonyl acid dissociable group,” which are described below.

[0032] 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 an acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociable group").

[0033] [ka] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Is, Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.

[0034] In formula (a1-r-1), Ra' 1and 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, the alkyl group may be the same as the alkyl group exemplified as the substituent that may be bonded to the carbon atom at the α-position in the explanation of the α-substituted acrylic acid ester above, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group is preferable. More specifically, 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 the like are preferable, and a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

[0035] 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. 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.

[0036] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably has 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, and is preferably an isopropyl group.

[0037] 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 thereof 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 preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0038] 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 a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Ra' 3Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0039] 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 "Ra x5 " Also known as ".) Here, R P1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R P2Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents or may have one or more of each of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an 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.

[0040] Ra' 3 But Ra' 1 , Ra' 2 When it is bonded to any one of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group, a tetrahydrofuranyl group, etc.

[0041] Tertiary alkyl ester type acid-labile group: Among the above polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-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 the sake of convenience.

[0042] [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.

[0043] Ra' 4 Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, or 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 is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 As the hydrocarbon group of Ra' 3 The same can be mentioned.

[0044] Ra' 5 and Ra' 6 and (a1-r2-3) are preferably used. 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).

[0045] [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 Is Ra' 10 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 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 or a hydrogen atom. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * indicates a bond.]

[0046] In the above formula (a1-r2-1), Ra' 10 represents a linear or branched alkyl group having 1 to 12 carbon atoms which may be partially substituted with a halogen atom or a heteroatom-containing group.

[0047] Ra' 10In the formula, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra' 10 As the branched alkyl group in the formula (I), 3 The same can be mentioned.

[0048] 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. In addition, some of the carbon atoms (e.g., methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. The heteroatom includes an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group 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-.

[0049] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed together with the carbon atom to which is bonded) is Ra' in formula (a1-r-1). 3 Among them, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl and cyclohexyl groups are more preferred.

[0050] 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) in the above formula. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of the substituent include the above-mentioned Ra' 3Examples of the substituents include those similar to those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 101 ~Ra 103 In the above 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 above formula, examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as 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; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]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 linear saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom is particularly preferable.

[0051] The above Ra 101 ~Ra 103 Examples of the substituents of the chain saturated hydrocarbon group or the cyclic saturated aliphatic hydrocarbon group represented by the formula x5 The same groups as those shown below can be mentioned.

[0052] Ra 101 ~Ra 103Examples of groups 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.

[0053] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is represented by 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.

[0054] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed by the group include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl 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.

[0055] In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of Ra' independently represents a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. 12 and Ra' 13In the above, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is 101 ~Ra 103 Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in the above formula are the same as those in the above formula. Some or all of the hydrogen atoms in the chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, a hydrogen atom or an alkyl group having 1 to 5 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group or an ethyl group is further preferable, and a methyl group is particularly preferable. The above Ra' 12 and Ra' 13 In the case where the chain saturated hydrocarbon group represented by the formula (I) is substituted, examples of the substituent include the above-mentioned Ra x5 The same groups as those shown below can be mentioned.

[0056] 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.

[0057] Ra' 14 The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. 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.

[0058] Ra' 14 The branched alkyl group in the above formula (I) preferably has 3 to 10 carbon atoms, and more preferably has 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, and is preferably an isopropyl group.

[0059] 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 thereof 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 preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0060] Ra' 14 As the aromatic hydrocarbon group in 104 Among them, the aromatic hydrocarbon group Ra' is the same as that 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 The substituents may be the same as those which may be possessed by the group.

[0061] 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 above formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. Ra' in formula (a1-r2-4) 14When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a1-r2-4) may be any one of the 1-position, 2-position, or 9-position of the anthryl group.

[0062] Specific examples of the group represented by formula (a1-r2-1) are shown below.

[0063] [ka]

[0064] [ka]

[0065] [ka]

[0066] Specific examples of the group represented by formula (a1-r2-2) are shown below.

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] Specific examples of the group represented by formula (a1-r2-3) are shown below.

[0071] [ka]

[0072] Specific examples of the group represented by formula (a1-r2-4) are shown below.

[0073] [ka]

[0074] 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").

[0075] [ka] [In the formula, Ra' 7 ~Ra' 9 are each an alkyl group.

[0076] In formula (a1-r-3), Ra' 7 ~Ra' 9 Each of the groups is preferably an alkyl group having 1 to 5 carbon atoms, and 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.

[0077] 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 an acrylamide, a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a portion 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 a portion of the hydrogen atoms in -C(═O)-OH are protected with a substituent containing the above-mentioned acid-decomposable group.

[0078] Of the above, the structural unit (a1) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position 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) or (a1-2).

[0079] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 1 is a divalent hydrocarbon group which may have an ether bond. a1 is an integer from 0 to 2. 1 is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-2). 1 is a2 +1-valent hydrocarbon group, n a2 is an integer from 1 to 3, and Ra 2 is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0080] In the formula (a1-1), the alkyl group of R 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 are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferable.

[0081] In the formula (a1-1), Va 1The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0082] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) 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 the structure.

[0083] 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 preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; 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.

[0084] Examples of the aliphatic hydrocarbon group containing a ring in the 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 linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, etc. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, 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 obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, specifically cycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0085] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the 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; aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom, etc. 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 (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 (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.

[0086] In the formula (a1-1), Ra 1 is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0087] In the formula (a1-2), Wa 1 n in a2The +1-valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. The aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that combines a straight-chain or branched-chain aliphatic hydrocarbon group with an aliphatic hydrocarbon group containing a ring in its structure. The above n a2 The +1 valency is preferably 2 to 4, more preferably 2 or 3.

[0088] In the formula (a1-2), Ra 2 is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0089] Specific examples of the structural unit represented by the formula (a1-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0090] [ka]

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] The structural unit (a1) contained in the component (A1) may be of one type, or two or more types. As the structural unit (a1), a structural unit represented by the above formula (a1-1) is more preferable, since it is easier to improve the characteristics (sensitivity, shape, etc.) in electron beam or EUV lithography. Among these, as the structural unit (a1), those containing a structural unit represented by general formula (a1-1-1) shown below are particularly preferable.

[0099] [ka] [In the formula, Ra 1 " is an acid-dissociable group represented by general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4).

[0100] In the formula (a1-1-1), R and Va 1 and n a1 R and Va in the formula (a1-1) 1 and n a1 is the same as: The acid dissociable group represented by formula (a1-r2-1), (a1-r2-3) or (a1-r2-4) is as described above. Among them, it is preferable to select the acid dissociable group as a cyclic group, since it is suitable for EB or EUV use in that the reactivity can be increased.

[0101] In the formula (a1-1-1), Ra 1Among the above, " is preferably an acid dissociable group represented by general formula (a1-r2-1).

[0102] The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 95 mol %, more preferably 10 to 90 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 60 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a1) is at least as large as the lower limit of the aforementioned preferred range, lithography properties such as sensitivity, resolution, and roughness can be 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.

[0103] 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, an -SO2- containing cyclic group, or a carbonate-containing cyclic group; a structural unit (a3) ​​containing a polar group-containing aliphatic hydrocarbon group; a structural unit (a4) containing an acid non-dissociable aliphatic cyclic group; and a structural unit (st) derived from styrene or a styrene derivative.

[0104] Regarding the structural unit (a10): The structural unit (a10) is a structural unit represented by general formula (a10-1) shown below.

[0105] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1.]

[0106] In the above formula (a10-1), 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 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. As the halogen atom, a fluorine atom is particularly preferable. 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.

[0107] 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.

[0108] Optionally substituted divalent hydrocarbon group: Ya x1 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.

[0109] Ya x1 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0110] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably contains 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 preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; 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.

[0111] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, which may include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0112] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the 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 linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group 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 obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0113] 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 further 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 the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups are 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-.

[0114] Ya x1 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, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the 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 a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group 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., 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 of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1 carbon atom.

[0115] 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 a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0116] Divalent linking groups containing heteroatoms: Ya x1is 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 a divalent linking group containing a hetero atom, 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 each independently represents 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-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 -Medium, Y 21 and Y 22Each of Ya is independently a divalent hydrocarbon group which may have a substituent. x1 Examples of the divalent linking group in the above formula (divalent hydrocarbon group which may have a substituent) include those mentioned above. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable. 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, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The 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, still 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, still more preferably 1 or 2, and most preferably 1.

[0117] Among the above, Ya x1is 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)-].

[0118] 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 4n+1) hydrogen atoms are removed. 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, 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 a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Also, Wa x1 The aromatic hydrocarbon group in the formula (n) may be an aromatic compound having an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1 As the aryl group, benzene, naphthalene, anthracene, or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed is preferred, and a group in which (n ax1 A group in which (n +1) hydrogen atoms have been removed from benzene is more preferable. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0119] Wa x1The 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, the alkoxy group, the halogen atom, and the halogenated alkyl group as the substituent include Ya x1 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.

[0120] 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.

[0121] Specific examples of the structural unit (a10) represented by the aforementioned formula (a10-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0122] [ka]

[0123] [ka]

[0124] [ka]

[0125] The structural unit (a10) contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains the structural unit (a10), the proportion of the structural unit (a10) in the component (A1) is preferably 5 to 95 mol %, more preferably 10 to 90 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 60 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a10) is at least as large as the lower limit of the above range, it is possible to further increase the sensitivity, whereas by ensuring that the proportion is at most the upper limit of the above range, it is easier to achieve a balance with other structural units.

[0126] Regarding the structural unit (a2): The component (A1) may further contain, in addition to the structural unit (a1), a structural unit (a2) containing a lactone-containing cyclic group, an -SO2- containing cyclic group, or a carbonate-containing cyclic group (provided that this does not correspond to the structural unit (a1)). The lactone-containing cyclic group, -SO2--containing cyclic group, or carbonate-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. In addition, the structural unit (a2) has the effects of, for example, appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development, thereby improving the lithography properties, etc.

[0127] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, and when there is further a ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any suitable group can be used. Specific examples include the groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0128] [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, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2- 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.

[0129] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. 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 formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. 21 Examples of the alkyl group include those groups in which the alkyl groups mentioned above are linked to an oxygen atom (-O-). Ra' 21 As the halogen atom in, a fluorine atom is preferable. Ra' 21 As the halogenated alkyl group in the above, Ra' 21 and groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the above halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0130] Ra' 21In -COOR" and -OC(=O)R", R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2- 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 has 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 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; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. 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. The carbonate-containing cyclic group in R″ is the same as the carbonate-containing cyclic group described later, and specific examples thereof include groups represented by general formulae (ax3-r-1) to (ax3-r-3). The -SO2-containing cyclic group in R'' is the same as the -SO2-containing cyclic group described later, and specific examples thereof include the groups represented by general formulas (a5-r-1) to (a5-r-4). Ra' 21 The hydroxyalkyl group in Ra' is preferably one having 1 to 6 carbon atoms. 21In the above formula, at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0131] Ra' 21 Among the above, it is preferable that each of them independently is a hydrogen atom or a cyano group.

[0132] In the general formulae (a2-r-2), (a2-r-3) and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A" is preferably a linear or branched alkylene group, 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 the carbon atoms of the alkylene group, and examples thereof include -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.

[0133] Specific examples of the groups represented by general formulas (a2-r-1) to (a2-r-7) are listed below.

[0134] [ka]

[0135] [ka]

[0136] The term "-SO2-containing cyclic group" refers to a cyclic group containing a ring containing -SO2- in its ring structure, specifically, a cyclic group in which the sulfur atom (S) in -SO2- forms a part of the ring structure of the cyclic group. The ring containing -SO2- in the ring structure is counted as the first ring, and if there is only this ring, it is called a monocyclic group, and if there is another ring structure, it is called a polycyclic group regardless of the structure. The -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2- containing cyclic group is preferably a cyclic group containing -O-SO2- in its ring skeleton, that is, a cyclic group containing a sultone ring in which -OS- in -O-SO2- forms a part of the ring skeleton. More specific examples of the -SO2- containing cyclic group include groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[0137] [ka] [In the formula, Ra' 51 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2- containing cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer of 0 to 2.

[0138] In the general formulae (a5-r-1) and (a5-r-2), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3) and (a2-r-5). Ra' 51 The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each represented by Ra' 21 Examples of the above-mentioned are similar to those mentioned in the explanation of the above. Specific examples of the groups represented by general formulas (a5-r-1) to (a5-r-4) are shown below, in which "Ac" represents an acetyl group.

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] The term "carbonate-containing cyclic group" refers to a cyclic group that contains a ring (carbonate ring) containing -OC(=O)-O- in its ring skeleton. The carbonate ring is counted as the first ring, and when there is only a carbonate ring, it is called a monocyclic group, and when there is another ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. The carbonate ring-containing cyclic group is not particularly limited and any one can be used. Specific examples include groups represented by the following general formulae (ax3-r-1) to (ax3-r-3).

[0143] [ka] [In the formula, Ra' x31 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2- containing cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, p' is an integer of 0 to 3, and q' is 0 or 1.

[0144] In the general formulae (ax3-r-2) to (ax3-r-3), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3) and (a2-r-5). Ra' 31The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each represented by Ra' 21 Examples of the above-mentioned are similar to those mentioned in the explanation of the above. Specific examples of the groups represented by the general formulae (ax3-r-1) to (ax3-r-3) are listed below.

[0145] [ka]

[0146] Of the various possibilities, the structural unit (a2) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0147] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 21 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, a carbonate-containing cyclic group, or a -SO2- containing cyclic group.

[0148] In the formula (a2-1), R is the same as defined above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

[0149] 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.

[0150] Optionally substituted divalent hydrocarbon group: Ya 21 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.

[0151] Ya 21 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0152] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably contains 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 preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; 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.

[0153] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, which may include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0154] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the 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 linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group 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 obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0155] 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 further 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 the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups are 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-.

[0156] Ya 21 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, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the 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 a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group 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., 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 of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1 carbon atom.

[0157] 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 a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0158] Divalent linking groups containing heteroatoms: Ya 21 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 a divalent linking group containing a hetero atom, 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 each independently represents 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-Y 21 -OY22 -, -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 Each of Ya is independently a divalent hydrocarbon group which may have a substituent. 21 Examples of the divalent linking group in the above formula (divalent hydrocarbon group which may have a substituent) include those mentioned above. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable. 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, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The 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, still 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, still more preferably 1 or 2, and most preferably 1.

[0159] Among the above, 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 above formula (a2-1), Ra 21 is a lactone-containing cyclic group, an -SO2- containing cyclic group, or a carbonate-containing cyclic group. Ra 21 Suitable examples of the lactone-containing cyclic group, the -SO2- containing cyclic group and the carbonate-containing cyclic group in the above formula (a2-r-1) to (a2-r-7), the groups represented by the general formulas (a5-r-1) to (a5-r-4) and the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) are respectively. Among these, a lactone-containing cyclic group or an -SO2- containing cyclic group is preferable, a group represented by the general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r-1) is more preferable, and a group represented by the general formula (a2-r-2) or (a5-r-1) is even more preferable. Specifically, any of the groups represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1), (r-sl-1-1), and (r-sl-1-18) are preferred, any of the groups represented by the chemical formulas (r-lc-2-1) to (r-lc-2-18), and (r-sl-1-1) are more preferred, and any of the groups represented by the chemical formulas (r-lc-2-1), (r-lc-2-12), and (r-sl-1-1) are even more preferred.

[0161] The structural unit (a2) contained in the component (A1) may be of one type, or two or more types. 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 5 to 60 mol%, more preferably 10 to 60 mol%, even more preferably 20 to 60 mol%, and particularly preferably 30 to 60 mol%. When the proportion of the structural unit (a2) is at least as large as the preferred lower limit, the effects achieved by including the structural unit (a2) as described above can be fully obtained. 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.

[0162] Regarding the structural unit (a3): In addition to the structural unit (a1), the component (A1) may further include a structural unit (a3) ​​(excluding those corresponding to the structural unit (a1) or the structural unit (a2)) that contains a polar group-containing aliphatic hydrocarbon group. When the component (A1) includes the structural unit (a3), the hydrophilicity of the component (A) is increased, which contributes to improving the resolution. In addition, the acid diffusion length can be appropriately adjusted.

[0163] Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which some of the hydrogen atoms of an alkyl group are substituted with fluorine atoms, with a hydroxyl group being particularly preferred. Examples of the aliphatic hydrocarbon group include linear or branched hydrocarbon groups having 1 to 10 carbon atoms (preferably alkylene groups) and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be a monocyclic group or a polycyclic group, and can be appropriately selected from the many groups proposed for use in resins for resist compositions for ArF excimer lasers.

[0164] When the cyclic group is a monocyclic group, the number of carbon atoms is more preferably 3 to 10. Among them, a structural unit derived from an acrylic acid ester containing an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which a portion of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is more preferred. Examples of the monocyclic group include groups in which two or more hydrogen atoms have been removed from a monocycloalkane. Specific examples include groups in which two or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane, cyclohexane, and cyclooctane. Among these monocyclic groups, groups in which two or more hydrogen atoms have been removed from cyclopentane and groups in which two or more hydrogen atoms have been removed from cyclohexane are industrially preferred.

[0165] When the cyclic group is a polycyclic group, the number of carbon atoms of the polycyclic group is more preferably 7 to 30. Among them, a structural unit derived from an acrylic acid ester containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which a portion of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from a bicycloalkane, a tricycloalkane, a tetracycloalkane, etc. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane are industrially preferred.

[0166] There are no particular limitations on the structural unit (a3), and any structural unit can be used as long as it contains a polar group-containing aliphatic hydrocarbon group. The structural unit (a3) ​​is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and which contains a polar group-containing aliphatic hydrocarbon group. As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a straight-chain or branched-chain hydrocarbon group having 1 to 10 carbon atoms, a structural unit derived from a hydroxyethyl ester of acrylic acid is preferred. Furthermore, when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, preferred examples of the structural unit (a3) ​​include structural units represented by the following formulae (a3-1), (a3-2), and (a3-3); when the hydrocarbon group is a monocyclic group, preferred examples of the structural unit (a3) ​​include structural units represented by formula (a3-4).

[0167] [ka] [In the formula, R is the same as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, l is an integer of 0 to 5, and s is an integer of 1 to 3.]

[0168] In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3rd position of the adamantyl group. It is preferable that j is 1, and it is particularly preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0169] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

[0170] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxyl group of the acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5- or 6-position of the norbornyl group.

[0171] In formula (a3-4), t' is preferably 1 or 2. l is preferably 0 or 1. s is preferably 1. The fluorinated alkyl alcohol is preferably bonded to the 3- or 5-position of the cyclohexyl group.

[0172] The structural unit (a3) ​​contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains the structural unit (a3), the proportion of the structural unit (a3) ​​relative to the total (100 mol %) of all structural units constituting the component (A1) is preferably 1 to 30 mol %, more preferably 2 to 25 mol %, and even more preferably 5 to 20 mol %. By ensuring that the proportion of the structural unit (a3) ​​is at least as large as the preferred lower limit, the effects described above can be fully achieved by including the structural unit (a3). By ensuring that the proportion of the structural unit (a3) ​​is at most the preferred upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0173] Regarding the structural unit (a4): The component (A1) may further contain, in addition to the structural unit (a1), a structural unit (a4) that contains an acid non-dissociable aliphatic cyclic group. By including the structural unit (a4) in the component (A1), the dry etching resistance of the formed resist pattern is improved. In addition, the hydrophobicity of the component (A) is enhanced. The improved hydrophobicity contributes to improvements in the resolution, resist pattern shape, etc., particularly in the case of a solvent development process. The “acid non-dissociable cyclic group” within the structural unit (a4) is a cyclic group that, when acid is generated in the resist composition upon exposure (for example, when acid is generated from a structural unit that generates acid upon exposure or from the component (B)), does not dissociate even when acted upon by the acid, and remains as is within the structural unit.

[0174] The structural unit (a4) is preferably, for example, a structural unit derived from an acrylate ester containing an acid non-dissociable aliphatic cyclic group. The cyclic group can be any of a large number of conventionally known resin components for resist compositions for ArF excimer lasers, KrF excimer lasers (preferably ArF excimer lasers), etc. The cyclic group is preferably at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group, in view of industrial availability, etc. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent. Specific examples of the structural unit (a4) include the structural units represented by the following general formulas (a4-1) to (a4-7).

[0175] [ka] [In the formula, R α is the same as above.]

[0176] The structural unit (a4) contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains the structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 40 mol %, and more preferably 5 to 20 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a4) is at least as large as the preferred lower limit, the effects of including the structural unit (a4) can be fully obtained, while by ensuring that the proportion is no more than the preferred upper limit, it becomes easier to achieve a balance with other structural units.

[0177] Regarding the structural unit (st): The structural unit (st) is a structural unit derived from styrene or a styrene derivative. A "structural unit derived from styrene" refers to a structural unit formed by cleavage of the ethylenic double bond of styrene. A "structural unit derived from a styrene derivative" refers to a structural unit formed by cleavage of the ethylenic double bond of a styrene derivative.

[0178] The term "styrene derivative" refers to a compound in which at least some of the hydrogen atoms of styrene are substituted with a substituent. Examples of styrene derivatives include those in which the hydrogen atom at the α-position of styrene is substituted with a substituent, those in which one or more hydrogen atoms on the benzene ring of styrene are substituted with a substituent, and those in which the hydrogen atom at the α-position of styrene and one or more hydrogen atoms on the benzene ring are substituted with a substituent.

[0179] Examples of the substituent that substitutes the hydrogen atom at the α-position of styrene include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms. 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 are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. The substituent substituting the hydrogen atom at the α-position of styrene is preferably an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms or a fluorinated alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group from the viewpoint of industrial availability.

[0180] Examples of the substituent that substitutes the hydrogen atom on the benzene ring of styrene include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl 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 further 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 the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups are substituted with the halogen atoms. The substituent that substitutes the hydrogen atom on the benzene ring of styrene is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0181] The structural unit (st) is preferably a structural unit derived from styrene, or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, more preferably a structural unit derived from styrene, or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with a methyl group, and even more preferably a structural unit derived from styrene.

[0182] The structural unit (st) contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains the structural unit (st), the proportion of the structural unit (st) is preferably 1 to 30 mol %, and more preferably 3 to 20 mol %, based on the total (100 mol %) of all structural units constituting the component (A1).

[0183] 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. In the resist composition of this embodiment, the component (A1) can be a polymeric compound that has a repeating structure of the structural unit (a1), and preferably a polymeric compound that has a repeating structure of the structural unit (a1) and the structural unit (a10). Of the above, suitable examples of the component (A1) include polymeric compounds consisting of repeating structures of the structural units (a1) and (a10).

[0184] In a polymeric compound having a repeating structure of 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 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%. Furthermore, the proportion of the structural unit (a10) in the polymer compound is preferably from 10 to 90 mol%, more preferably from 20 to 80 mol%, even more preferably from 30 to 70 mol%, and particularly preferably from 40 to 60 mol%, based on the total (100 mol%) of all structural units constituting the polymer compound.

[0185] The molar ratio of the structural unit (a1) to the structural unit (a10) in the polymer compound (structural unit (a1):structural unit (a2)) is preferably 2:8 to 8:2, more preferably 3:7 to 7:3, and even more preferably 4:6 to 6:4.

[0186] The (A1) component can be produced by dissolving 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. Alternatively, the component (A1) can be produced by dissolving a monomer that derives the structural unit (a1) and, if necessary, a monomer that derives a structural unit other than the structural unit (a1) (for example, the structural unit (a10)) in a polymerization solvent, adding the above-mentioned radical polymerization initiator to the resulting solution to polymerize, and then carrying out a deprotection reaction. In addition, 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 end. In this way, a copolymer having a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms is introduced, which is effective in reducing development defects and LER (line edge roughness: unevenness of the line sidewall).

[0187] The weight average molecular weight (Mw) of the component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. When the Mw of the component (A1) is no more than 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 no less than the preferred lower limit of this range, the dry etching resistance and cross-sectional shape of the resist pattern are excellent. 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.

[0188] Regarding component (A2) The resist composition of this embodiment may use, in combination with 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 under the action of an acid. There are no particular restrictions on the component (A2), and it may be selected from the many conventional base components for chemically amplified resist compositions. The component (A2) may be a polymeric compound or a low molecular weight compound, and may be used either alone or in combination of two or more.

[0189] The proportion of the (A1) component in the (A) component is preferably 25% by mass or more, more preferably 50% by mass or more, and even more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of the (A) component. When the proportion is 25% by mass or more, a resist pattern that is excellent in various lithography properties such as high sensitivity, resolution, and improved roughness is easily formed.

[0190] 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.

[0191] <Acid generator component (B)> The resist composition of the present embodiment further contains, in addition to the component (A), an acid generator component (B) that generates acid upon exposure. There are no particular limitations on the component (B), and any of the compounds that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts; oxime sulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes; nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0192] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0193] [ka] [In the formula, R 101 and R 104 ~R 108R each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 104 and R 105 R may be bonded to each other to form a ring structure. 102 Y is a fluorine atom or a fluorine-containing alkyl group having 1 to 5 carbon atoms. 101 is a divalent linking group containing an oxygen atom or a single bond. 101 ~V 103 Each of L is independently a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 Each of L is independently a single bond or an oxygen atom. 103 ~L 105 are each independently a single bond, -CO- or -SO2-. m is an integer of 1 or more, m+ is an onium cation with a valence of m.

[0194] {anion part} Anion in component (b-1) In formula (b-1), R 101 represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0195] 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. 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.

[0196] R 101The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R 101 Specific examples of the aromatic ring of 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, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R 101 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, a phenyl group, a naphthyl group, etc.), and 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.). 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.

[0197] R 101 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 present 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 obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; or a polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton.

[0198] Among them, R 101 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0199] 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, further preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; 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.

[0200] Also, R 101 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), -SO2--containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4), and heterocyclic groups represented by the following chemical formulae (r-hr-1) to (r-hr-16). * in the formula represents Y in formula (b-1). 101 Represents a bond that bonds to .

[0201] [ka]

[0202] R 101 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, 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. Examples of the halogen atom as a 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 a substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the 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.

[0203] R 101 The cyclic hydrocarbon group in may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a polycyclic skeleton of a bridged ring system to which one or more aromatic rings are fused. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. 101 Specific examples of the fused cyclic group in the formula (b-1) include those represented by the following formulas (r-br-1) to (r-br-2). 101 Represents a bond that bonds to .

[0204] [ka]

[0205] R 101 Examples of the substituent that the fused cyclic group in the formula (I) may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused ring group are defined as R 101 Examples of the substituents of the cyclic group in the above formula (I) include the same as those exemplified as the substituents of the cyclic group in the above formula (I). 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 the 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 obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane or cyclohexane; groups obtained by removing one hydrogen atom 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.

[0206] A chain alkyl group which may have a substituent: R 101 The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10. 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.

[0207] An optionally substituted chain alkenyl group: R 101 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a 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 above chain alkenyl groups, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0208] R 101 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the above-mentioned R 101 and the like.

[0209] Among the above, R 101 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, the cyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane or a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused, more preferably an adamantyl group, a group represented by the above formula (r-br-1), or a group represented by the above formula (r-br-2), and even more preferably an adamantyl group or a group represented by the above formula (r-br-1).

[0210] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 When Y is a divalent linking group containing an oxygen atom, 101 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of the divalent linking group containing an oxygen atom include non-hydrocarbon oxygen-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-OC(=O)-O-); and combinations of the non-hydrocarbon oxygen-containing linking groups and alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of the divalent linking group containing an oxygen atom include linking groups represented by the following general formulae (y-al-1) to (y-al-7). In the following general formulae (y-al-1) to (y-al-7), R in the above formula (b-1) 101 The bond to V' in the following general formulas (y-al-1) to (y-al-7) is 101 It is.

[0211] [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.

[0212] 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.

[0213] 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 above 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 above formula (a1-r-1). 3 A divalent group in which one hydrogen atom has been further removed from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group, a polycyclic aliphatic hydrocarbon group) such as those mentioned above is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0214] Y 101 As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, and the linking groups represented by the above formulas (y-al-1) to (y-al-5) are more preferable.

[0215] In formula (b-1), V 101 is a single bond, an alkylene group or a fluorinated alkylene group. 101 The alkylene group and fluorinated alkylene group in the formula (I) preferably have 1 to 4 carbon atoms. 101 The fluorinated alkylene group in 101 In particular, the alkylene group represented by the formula (I) is preferably a group in which some or all of the hydrogen atoms of the alkylene group are substituted with fluorine atoms. 101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0216] In formula (b-1), R 102 R is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0217] Specific examples of the anion moiety represented by the formula (b-1) include, for example, Y 101 When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; 101 When is a divalent linking group containing an oxygen atom, examples of the anions include those represented by any of the following formulas (an-1) to (an-3).

[0218] [ka] [In the formula, R” 101R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by each of the above chemical formulas (r-hr-1) to (r-hr-6), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), or a chain alkyl group which may have a substituent. 102 R" is an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or an -SO2- containing cyclic group represented by each of the above general formulas (a5-r-1) to (a5-r-4). 103 V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. 101 R is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Each v" is independently an integer of 0 to 3, each q" is independently an integer of 0 to 20, and n" is 0 or 1.

[0219] R” 101 , R.” 102 and R.” 103 The aliphatic cyclic group which may have a substituent is represented by R 101 As the substituent, R in the formula (b-1) is preferably a group exemplified as the cyclic aliphatic hydrocarbon group. 101 Examples of the substituents which may substitute the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0220] R” 103 The aromatic cyclic group which may have a substituent in the formula (b-1) is 101 The substituent is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the formula (b-1). 101 The substituents which may substitute the aromatic hydrocarbon group in the above formula (I) are the same as those in the above formula (I).

[0221] R” 101 The chain alkyl group which may have a substituent in the formula (b-1) is R 101 The alkyl group is preferably one of the groups exemplified as the chain alkyl group in the above formula (I). R” 103 The chain alkenyl group which may have a substituent is represented by R 101 Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0222] Anion in component (b-2) In formula (b-2), R 104 , R 105 each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each represents R 101 However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105 is preferably a chain alkyl group which may have a substituent, and more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. 104 , R 105 The number of carbon atoms in the chain alkyl group of R is preferably as small as possible within the above range of carbon atoms, for reasons such as good solubility in a resist solvent. 104 , R 105In the chain alkyl group, the more hydrogen atoms substituted with fluorine atoms, the stronger the acid strength becomes, and the more the transparency to high-energy light of 250 nm or less and electron beams improves, which is preferable. The ratio of fluorine atoms in the chain alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103 each independently represents a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-1). 101 The same can be mentioned. In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0223] Anion in component (b-3) In formula (b-3), R 106 ~R 108 each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each represents R 101 The same can be mentioned. In formula (b-3), L 103 ~L 105 are each independently a single bond, -CO- or -SO2-.

[0224] Among the above, the anion moiety of the (B) component is preferably the anion in the (b-1) component, more preferably the anion represented by any one of the above general formulae (an-1) to (an-3), further preferably the anion represented by any one of the general formulae (an-1) or (an-2), and particularly preferably the anion represented by the general formula (an-2).

[0225] {cationic part} In the above formula (b-1), formula (b-2), and formula (b-3), M m+represents an onium cation having a valence of m. Among these, a sulfonium cation and an iodonium cation are preferred. m is an integer of 1 or greater.

[0226] Preferred cationic moieties ((M m+ ) 1 / m ) include organic cations represented by the following general formulas (ca-1) to (ca-5), respectively.

[0227] [ka] [In the formula, R 201 ~R 207 , and R 211 ~R 212 R each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209 R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 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-. 201 each independently represents an arylene group, an alkylene group, or an alkenylene group; x is 1 or 2. W 201 represents a (x+1)-valent linking group.

[0228] In the above general formulas (ca-1) to (ca-5), R 201 ~R 207 , and R 211 ~R 212 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R201 ~R 207 , and R 211 ~R 212 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 , and R 211 ~R 212 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 ~R 212 Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulas (ca-r-1) to (ca-r-7).

[0229] [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.

[0230] 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. 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.

[0231] R' 201The 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, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R' 201 Specific examples of the aromatic ring of 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, etc. 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 the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and 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.). 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.

[0232] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) includes 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 present 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 obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; or a polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton.

[0233] 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 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.

[0234] 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, further 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 preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; 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.

[0235] 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 -SO2- containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) above, and the heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) above.

[0236] 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.

[0237] A chain alkyl group which may have a substituent: R' 201 The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and most preferably has 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably has 3 to 15 carbon atoms, and most preferably has 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.

[0238] 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, further 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 above chain alkenyl groups, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0239] 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 R' 201 and the like.

[0240] 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.

[0241] 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), and an -SO2--containing cyclic group represented by each of the general formulae (a5-r-1) to (a5-r-4) are preferred.

[0242] In the above general formulas (ca-1) to (ca-5), R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they do not include a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, 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, in which a ring containing a sulfur atom in the ring skeleton in the formula is a 3- to 10-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.

[0243] 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.

[0244] 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) may be 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 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 formula (a5-r-1), an "-SO2-containing polycyclic group" is preferable, and a group represented by the above formula (a5-r-1) is more preferable.

[0245] Y 201 each independently represents an arylene group, an alkylene group, or an alkenylene group. Y 201 The arylene group in the above formula (b-1) is101 Examples of the aromatic hydrocarbon group in the above formula include groups in which one hydrogen atom has been removed from the aryl groups exemplified above. Y 201 The alkylene group and alkenylene group in the above formula (b-1) are 101 Examples of the chain alkyl group and the chain alkenyl group in the above formula (1) include groups in which one hydrogen atom has been removed from the groups exemplified as the chain alkyl group and the chain alkenyl group in the above formula (1).

[0246] In the above formula (ca-4), x is 1 or 2. W 201 is a (x+1)-valent linking group, that is, a divalent or trivalent linking group. W 201 The divalent linking group in the above formula (a2-1) is preferably a divalent hydrocarbon group which may have a substituent. 21 Examples of the divalent hydrocarbon groups which may have a substituent include those shown in the above. 201 The divalent linking group in may be linear, branched, or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferred. Examples of the arylene group include a phenylene group and a naphthylene group, and the phenylene group is particularly preferred. W 201 The trivalent linking group in 201 and a group in which one hydrogen atom has been removed from the divalent linking group represented by the formula: W 201 As the trivalent linking group in the formula (I), a group in which two carbonyl groups are bonded to an arylene group is preferable.

[0247] Specific examples of suitable cations represented by the above formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-72), respectively.

[0248] [ka]

[0249] [ka]

[0250] [ka] [In the formula, g1, g2, and g3 each represent a repeating number, 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.]

[0251] [ka]

[0252] [ka]

[0253] [ka]

[0254] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the above-mentioned 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

[0255] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0256] 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).

[0257] [ka]

[0258] Specific examples of suitable cations represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0259] [ka]

[0260] Specific examples of suitable cations represented by the formula (ca-5) include cations represented by the following general formulas (ca-5-1) to (ca-5-3).

[0261] [ka]

[0262] Among the above, the cationic part ((M m+ ) 1 / m ) is preferably a cation represented by general formula (ca-1).

[0263] In the resist composition of this embodiment, the component (B) may use either a single type, or a combination of two or more types. In the resist composition of this embodiment, the content of the component (B) per 100 parts by mass of the component (A) is preferably less than 40 parts by mass, more preferably 1 to 30 parts by mass, and even more preferably 5 to 30 parts by mass. By setting the content of the component (B) within the above-mentioned preferred range, sufficient pattern formation can be achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a homogeneous solution is easily obtained, and the storage stability of the resist composition is also favorable.

[0264] <Acid diffusion control agent component (D)> The resist composition of this embodiment further contains an acid diffusion controller component (D) in addition to the components (A) and (B). The component (D) contains a compound (D0) (hereinafter also referred to as "component (D0)") represented by the following general formula (d0):

[0265] [ka] [In the formula, Rd 0 is a fused ring group containing one or more fused rings each having an aromatic ring. The fused ring group has, as a substituent, an acid-decomposable group that is decomposed by the action of an acid to generate a polar group. 0 is a divalent linking group or a single bond. m+ represents an organic cation having a valence of m, where m is an integer of 1 or more.

[0266] {Anion part of component (D0)} In the above formula (d0), Rd 0 is a fused ring group containing one or more aromatic rings and having an acid decomposable group. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of heteroatoms in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

[0267] Rd 0 The fused ring group in may be a polycyclic aromatic ring group in which a plurality of the above aromatic rings are fused together, or an aromatic ring-aliphatic hydrocarbon ring fused ring group in which the above aromatic ring is fused with an aliphatic hydrocarbon ring.

[0268] Specific examples of the polycyclic aromatic ring group include 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. Rd 0Specific examples of the polycyclic aromatic ring group in the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, 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 phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0269] Rd 0 Examples of the aromatic ring-aliphatic hydrocarbon ring fused cyclic group in the above formula include fluorene; a polycycloalkane having a polycyclic skeleton of a bridged ring system, to which one or more aromatic rings are fused, etc. Specific examples of the bridged ring polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The aromatic ring-aliphatic hydrocarbon ring 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 (r-br-1) to (r-br-2) include the groups represented by the formulas (r-br-1) to (r-br-2). In this case, * in the formulas (r-br-1) to (r-br-2) represents Yd 0 Represents a bond that bonds to .

[0270] In the above formula (d0), Rd 0 Among the above, the fused ring group in is preferably an aromatic ring-aliphatic hydrocarbon ring fused ring group, more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, even more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane, and further preferably a group represented by the above formulas (r-br-1) to (r-br-2).

[0271] In the above formula (d0), Rd0 The fused cyclic group in has, as a substituent, an acid-decomposable group that decomposes under the action of an acid to generate a polar group. Specific examples of the acid-dissociable group that constitutes the acid-decomposable group include "acetal-type acid-dissociable group", "tertiary alkyl ester-type acid-dissociable group", and "tertiary alkyloxycarbonyl acid-dissociable group". Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO3H).

[0272] Acetal type acid dissociable group: Examples of the acid-dissociable group that protects a hydroxyl group include acid-dissociable groups represented by the following general formula (a1-r-1).

[0273] [ka] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Is, Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.

[0274] Tertiary alkyl ester type acid-labile group: Examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2).

[0275] [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.

[0276] Tertiary alkyloxycarbonyl acid dissociating group: Examples of the acid-dissociable group that protects a hydroxyl group include acid-dissociable groups represented by the following general formula (a1-r-3).

[0277] [ka] [In the formula, Ra' 7 ~Ra' 9 are each an alkyl group.

[0278] Examples of the “acetal-type acid dissociable group”, “tertiary alkyl ester-type acid dissociable group”, and “tertiary alkyloxycarbonyl acid dissociable group” are the same as the “acetal-type acid dissociable group”, “tertiary alkyl ester-type acid dissociable group”, and “tertiary alkyloxycarbonyl acid dissociable group” explained above in relation to the structural unit (a1) of the component (A).

[0279] Rd 0 The acid-dissociable group constituting the acid-decomposable group of the fused cyclic group in is not particularly limited, and may be an acid-dissociable group other than the above-mentioned "acetal-type acid-dissociable group", "tertiary alkyl ester-type acid-dissociable group", and "tertiary alkyloxycarbonyl acid-dissociable group".

[0280] Rd 0 Of the above, the acid-decomposable group contained in the fused cyclic group in is preferably an acid-decomposable group represented by the following general formula (pg-1).

[0281] [ka] [In formula (pg-1), Rpg is an acid dissociable group represented by the following general formula (pg-r-1), an acid dissociable group represented by the following general formula (pg-r-2), an acid dissociable group represented by the following general formula (pg-r-3), or an acid dissociable group represented by the following general formula (pg-r-4). * represents a bond.]

[0282] [ka] [In formula (pg-r-1), Rd 1 ~Rd 3 are each independently a hydrocarbon group, Rd 1 and Rd 2 may be bonded to each other to form a ring. In formula (pg-r-2), Rd 001 is a linear or branched aliphatic hydrocarbon group. 002 Rd is a single bond or a divalent linking group. 002 is a hydrogen atom or a substituent. Ar is a benzene ring or a naphthalene ring. Rm 01 is a substituent. n01 is an integer of 1 to 4. In formula (pg-r-3), Xd is a secondary carbon atom. X is an alicyclic hydrocarbon ring which may have a substituent. Ar is a benzene ring or a naphthalene ring. Rm 02 is a substituent. n02 is an integer of 1 to 4. In formula (pg-r-4), Rd' 1 , Rd' 2 Rd' is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Rd' 3 is Rd' 1 , Rd' 2 may be bonded to any one of the following to form a ring. * indicates a bond to the oxygen atom (-O-) in general formula (pg-1).

[0283] Examples of the acid dissociable group represented by general formula (pg-r-1) include the same as the acid dissociable group represented by general formula (a1-r-2) in the structural unit (a1) of the component (A) described above. That is, Rd in the above general formula (pg-r-1) 1 and Ra' in the above general formula (a1-r-2) 4 Rd in the above general formula (pg-r-1) 2 and Ra' in the above general formula (a1-r-2) 5 Rd in the above general formula (pg-r-1) 3 and Ra' in the above general formula (a1-r-2) 6 The terms "a" and "b" refer to similar things.

[0284] In the acid dissociable group represented by the above general formula (pg-r-1), Rd 1 and Rd 2 When they are bonded to each other to form a ring, suitable examples of such a ring include a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2), and a group represented by the following general formula (a1-r2-3). On the other hand, Rd 1 ~Rd 3 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).

[0285] [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 Is Ra' 10 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 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' 13are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * indicates a bond.]

[0286] Examples of the groups represented by general formulas (a1-r2-1) to (a1-r2-4) include the same groups represented by general formulas (a1-r2-1) to (a1-r2-4) as those in the structural unit (a1) of the component (A) described above.

[0287] In the above general formula (pg-r-2), Rd 001 is a linear or branched aliphatic hydrocarbon group. Rd 001 The linear or branched aliphatic hydrocarbon group in is preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 20 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, a 1-methylethyl group, a 1-methylpropyl group, or a 2-methylpropyl group, and still more preferably a methyl group.

[0288] In the above general formula (pg-r-2), Yd 002 is a single bond or a divalent linking group. 002 Examples of the divalent linking group in the structural unit (a10) of the component (A) include x1 Specifically, preferred examples include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.

[0289] Yd 002 Among the above, is preferably a single bond or a straight-chain or branched aliphatic hydrocarbon group, more preferably a single bond or a straight-chain aliphatic hydrocarbon group, still more preferably a single bond, a methylene group [-CH-] or an ethylene group [-(CH)-], particularly preferably a single bond or a methylene group [-CH-], and most preferably a single bond.

[0290] In the above general formula (pg-r-2), Rd002 is a hydrogen atom or a substituent. 002 Examples of the substituent in include a carboxy group, a hydroxy group, an amino group, a sulfo group, a halogen atom, a halogenated alkyl group, an alkoxy group, an alkyloxycarbonyl group, a nitro group, and the like. Of these, a hydroxy group is preferred. Rd 002 Among the above, is preferably a hydrogen atom or a hydroxyl group, and more preferably a hydrogen atom.

[0291] In the above general formula (pg-r-2), Ar is a benzene ring or a naphthalene ring, and is preferably a benzene ring.

[0292] In the above general formula (pg-r-2), Rm 01 Specific examples of the substituent in include a carboxy group, a hydroxy group, an amino group, a sulfo group, a halogen atom, a halogenated alkyl group, an alkoxy group, an alkyloxycarbonyl group, a nitro group, and the like. Of these, a hydroxy group is preferred. In the above general formula (pg-r-2), Rm 01 is preferably a hydrogen atom.

[0293] In the above general formula (pg-r-2), n01 is an integer of 1 to 4, and preferably 1 or 2.

[0294] In the above general formula (pg-r-3), X is an alicyclic hydrocarbon ring which may have a substituent. The alicyclic hydrocarbon ring is preferably an alicyclic hydrocarbon ring having 4 to 20 carbon atoms, more preferably an alicyclic hydrocarbon ring having 5 to 15 carbon atoms, and even more preferably an alicyclic hydrocarbon ring having 5 to 10 carbon atoms. Specific examples include aliphatic rings such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, and cyclododecane, and spiroalkanes such as spiro[4.5]decane and spiro[5.5]undecane.

[0295] In the above general formula (pg-r-3), Ar is a benzene ring or a naphthalene ring, and is preferably a benzene ring.

[0296] In the above general formula (pg-r-3), Rm 02 Specific examples of the substituent in include a carboxy group, a hydroxy group, an amino group, a sulfo group, a halogen atom, a halogenated alkyl group, an alkoxy group, an alkyloxycarbonyl group, a nitro group, and the like. Of these, a hydroxy group is preferred.

[0297] In the above general formula (pg-r-3), n02 is an integer of 1 to 4, and preferably 1 or 2.

[0298] Examples of the acid dissociable group represented by general formula (pg-r-4) above include the same acid dissociable groups as those represented by formula (a1-r-1) in the structural unit (a1) of the component (A) described above. That is, Rd' in the above general formula (pg-r-4) 1 and Ra' in the above general formula (a1-r-1). 1 Rd' in the above general formula (pg-r-4) 2 and Ra' in the above general formula (a1-r-1). 2 Rd' in the above general formula (pg-r-4) 3 and Ra' in the above general formula (a1-r-1). 3 The terms "a" and "b" refer to similar things.

[0299] From the viewpoint of further improving the acid dissociability, Rpg in the acid decomposable group represented by the above general formula (pg-1) is preferably one having a cyclic acid dissociable group, more preferably an acid dissociable group represented by any of the above general formulae (pg-r-1) to (pg-r-3), and even more preferably an acid dissociable group represented by the above general formula (pg-r-1). More specifically, Rpg is preferably an acid dissociable group represented by general formula (a1-r2-1).

[0300] When Rpg in the acid-decomposable group represented by the above general formula (pg-1) is an acid-dissociable group represented by the above general formula (a1-r2-1), Ra′ in the above general formula (a1-r2-1) 10 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and more preferably a linear alkyl group having 1 to 5 carbon atoms. In addition, Ra' in the above general formula (a1-r2-1) 11 (Ra' 10 The alicyclic group formed together with the carbon atom to which is bonded) is preferably a monocyclic alicyclic hydrocarbon group, and specifically, a cyclopentyl group or a cyclohexyl group is more preferable.

[0301] In the above formula (d0), Rd 0 The fused cyclic group in may have a substituent other than the above-mentioned acid-decomposable group. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, and a carbonyl 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.

[0302] In the formula (d0), Yd 0 represents a divalent linking group or a single bond. Yd0 The divalent linking group in is preferably a divalent linking group containing an oxygen atom. Yd 0 When Yd is a divalent linking group containing an oxygen atom, 0 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of divalent linking groups containing an oxygen atom include non-hydrocarbon oxygen-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-OC(=O)-O-); and combinations of the non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination.

[0303] Yd 0 As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, and a linking group represented by the following general formula (y-d0-1) or (y-d0-2) is more preferable.

[0304] [ka] [Wherein, Yd 001 and Yd 002 are each independently an aliphatic hydrocarbon group having 1 to 4 carbon atoms. * represents Rd 0 represents a bond to the carbon atom of the carbonyl group in the above general formula (d0).

[0305] Yd in the above general formula (y-d0-1) 001 And Yd in the above general formula (y-d0-2) 002 are each independently an aliphatic hydrocarbon group having 1 to 4 carbon atoms. The aliphatic hydrocarbon group includes an alkylene group, an alkenylene group, an alkadienylene group, an alkatrienylene group, an alkynylene group, or a combination of these groups.

[0306] Alkylene group with 1 to 4 carbon atoms Examples of the linear alkylene group having 1 to 4 carbon atoms include a methylene group, an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], and a tetramethylene group [-(CH2)4-]. Examples of branched alkylene groups having 2 to 4 carbon atoms include alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, etc.; and alkyl trimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-, etc.

[0307] Alkenylene group having 2 to 4 carbon atoms The alkenylene group having 2 to 4 carbon atoms may be a straight-chain alkenylene group or a branched-chain alkenylene group. Examples of the linear alkenyl group having 2 to 4 carbon atoms include an ethenylene group (vinylene group), a 1-propenylene group, a 2-propenylene group, and a butynylene group. Examples of the branched alkenyl group having 3 or 4 carbon atoms include a 1-methylvinylene group, a 1-methylpropenylene group, and a 2-methylpropenylene group.

[0308] Alkadienylene group, alkatrienylene group Examples of the alkadienylene group having 3 or 4 carbon atoms include a propadienylene group and a butadienylene group, and an example of the alkatrienylen group having 4 carbon atoms includes a butatrienylene group.

[0309] Alkynylene group having 2 to 4 carbon atoms Examples of the alkynylene group having 2 to 4 carbon atoms include an ethynylene group (-C≡C-).

[0310] As a combination of an alkylene group, an alkenylene group, an alkadienylene group, an alktrienylene group, and an alkynylene group, for example, a combination of an alkylene group and an alkynylene group is preferable. Specifically, a -CH2-C≡C- group is preferable.

[0311] Yd in the above general formula (y-d0-1) 001 And Yd in the above general formula (y-d0-2) 002 Among the above, each of them is preferably an alkylene group having 1 to 4 carbon atoms, or a combination of an alkylene group and an alkynylene group having a total of 1 to 4 carbon atoms, and more preferably an alkylene group having 1 or 2 carbon atoms, or a -CH2-C≡C- group.

[0312] In this embodiment, from the standpoint of improving CDU and resolution, the anion moiety of the component (D0) is preferably an anion represented by the following general formula (d0-an0).

[0313] [ka] [In the formula, Rx 1 ~Rx 4 Ry each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or two or more of them may be bonded to each other to form a ring structure. 1 ~Ry 2 each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or may be mutually bonded to form a ring structure. [ka] is a double bond or a single bond. 1 ~Rz 4 Each independently represents a hydrocarbon group which may have a substituent, if the atomic valence allows, or a hydrogen atom, or two or more may be bonded together to form a ring structure.1 ~Rx 4 2 or more, Ry 1 ~Ry 2 , or Rz 1 ~Rz 4 Two or more of Rx are bonded to each other to form an aromatic ring. 1 ~Rx 4 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of Rx has an anion group represented by the following general formula (d0-r-an1), and the entire anion portion is an n-valent anion. 1 ~Rx 4 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of the groups has an acid-decomposable group. n is an integer of 1 or more.]

[0314] [ka] [Wherein, Yd 0 is a divalent linking group or a single bond. * indicates a bond.]

[0315] In the formula (d0-an0), Rx 1 ~Rx 4 each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or two or more may be bonded to each other to form a ring structure. Ry 1 ~Ry 2 each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or may be mutually bonded to form a ring structure. Rz 1 ~Rz 4 each independently, if permitted by atomic valence, represents a hydrocarbon group which may have a substituent or a hydrogen atom, or two or more may be bonded to each other to form a ring structure.

[0316] Rx 1 ~Rx 4 , Ry1 ~Ry 2 , Rz 1 ~Rz 4 The hydrocarbon groups in each of the above may be either aliphatic hydrocarbon groups or aromatic hydrocarbon groups, and may be either cyclic or chain hydrocarbon groups. For example, Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 In the formula (I), examples of the hydrocarbon group which may have a substituent include a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, and a chain-like alkenyl group which may have a substituent.

[0317] 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. 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. In addition, Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle.

[0318] Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 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, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Rx1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 Specific examples of the aromatic ring of the aromatic hydrocarbon group in the formula (I) include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which a part of the carbon atoms constituting these aromatic rings is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 From the viewpoint of compatibility with component (A), the aromatic ring of the aromatic hydrocarbon group in formula (I) preferably does not contain a heteroatom, and an aromatic ring such as benzene, fluorene, naphthalene, anthracene, phenanthrene, or biphenyl is more preferable. Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 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, a phenyl group, a naphthyl group, etc.), and 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.). 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.

[0319] Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 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 present 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, specifically, cyclopentane, cyclohexane, etc. 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.

[0320] 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 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; 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.

[0321] Also, Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 The cyclic group is, for example, -COOR XYZ , -OC(=O)R XYZ About R XYZ Also included are those in which is a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -SO2-containing cyclic group.

[0322] Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 The substituents in the cyclic group of Rd 0 Examples of the substituents include those which may be possessed by the polycyclic aromatic cyclic group in the above formula (I). Rx 1 ~Rx 4 , Ry1 ~Ry 2 , Rz 1 ~Rz 4 Of the above, the substituent on the cyclic group is preferably an alkyl group, a halogen atom, or a halogenated alkyl group, from the viewpoint of compatibility with the component (A).

[0323] A chain alkyl group which may have a substituent: Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specific examples 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 decanyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group, and a docosyl group. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably has 3 to 15 carbon atoms, and most preferably has 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1,1-dimethylethyl 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.

[0324] An optionally substituted chain alkenyl group: Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, further 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-propenyl group, a 2-propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group.

[0325] Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 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 Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 Among them, Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 From the viewpoint of compatibility with component (A), the substituent in the chain alkyl or alkenyl group of Rx may be a halogen atom, a halogenated alkyl group, or the above-mentioned Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 The groups mentioned as the cyclic group in the formula (I) are preferred.

[0326] In the above formula (d0-an0), Ry 1 ~Ry 2 may be bonded to each other to form a ring structure. It takes Ry 1 ~Ry 2The ring structure formed by is one side (Ry 1 and Ry 2 and the bond between the carbon atoms to which each of the carbon atoms is bonded is shared, and this ring structure may be an alicyclic hydrocarbon or an aromatic hydrocarbon. In addition, this ring structure may be a polycyclic structure formed with other ring structures.

[0327] Ry 1 ~Ry 2 The alicyclic hydrocarbon formed by may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon, a monocycloalkane is preferable. As the monocycloalkane, one having 3 to 6 carbon atoms is preferable, and specific examples thereof include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon, a polycycloalkane is preferable. As the polycycloalkane, one having 7 to 30 carbon atoms is preferable.

[0328] Ry 1 ~Ry 2 Examples of the aromatic hydrocarbon ring formed by Ry include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which a part of the carbon atoms constituting these aromatic rings is replaced with a heteroatom. 1 ~Ry 2 From the viewpoint of compatibility with the component (A), the aromatic hydrocarbon ring formed by the formula (I) preferably does not contain a heteroatom, and an aromatic ring such as benzene, fluorene, naphthalene, anthracene, phenanthrene, or biphenyl is more preferable.

[0329] Ry 1 ~Ry 2 The ring structure (alicyclic hydrocarbon, aromatic hydrocarbon) formed by may have a substituent. The substituent here may be any of the above-mentioned Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4The substituents in the cyclic group of Ry (for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, a carbonyl group, etc.) are the same as those in the cyclic group of Ry. 1 ~Ry 2 From the viewpoint of compatibility with the component (A), the substituent in the ring structure formed by is preferably an alkyl group, a halogen atom, or a halogenated alkyl group.

[0330] Ry 1 ~Ry 2 The ring structure formed by is more preferably an aromatic hydrocarbon which may have a substituent.

[0331] In the above formula (d0-an0), Rz 1 ~Rz 4 Two or more of Rz may be bonded to each other to form a ring structure. 1 is Rz 2 ~Rz 4 Specifically, one side (Rz 1 and Rz 2 and the carbon atom to which Rz is bonded. 3 and Rz 4 A ring structure sharing a bond with the carbon atom to which Rz is attached 1 and Rz 2 A ring structure formed by bonding with Rz 3 and Rz 4 and a ring structure formed by bonding with Rz required 1 ~Rz 4 The ring structure formed by two or more of the above may be an alicyclic hydrocarbon or an aromatic hydrocarbon, preferably an aromatic hydrocarbon, and may be a polycyclic structure formed with other ring structures.

[0332] Rz 1 ~Rz 4The alicyclic hydrocarbon formed by two or more of the above may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon, a monocycloalkane is preferable. As the monocycloalkane, one having 3 to 6 carbon atoms is preferable, specifically, cyclopentane, cyclohexane, etc. are mentioned. As the polycyclic alicyclic hydrocarbon, a polycycloalkane is preferable. As the polycycloalkane, one having 7 to 30 carbon atoms is preferable, specifically, a polycycloalkane having a crosslinked ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; and a polycycloalkane having a condensed ring polycyclic skeleton such as a cyclic group having a steroid skeleton is more preferable. It may be a heterocyclic structure in which some of the carbon atoms are replaced with heteroatoms, and a nitrogen-containing heterocycle is particularly preferred, specifically, a cyclic imide or the like.

[0333] Rz 1 ~Rz 4 Examples of the aromatic hydrocarbon ring formed by two or more of Rz 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. 1 ~Rz 4 From the viewpoint of compatibility with the component (A), the aromatic hydrocarbon ring formed by two or more of these preferably does not contain a heteroatom, and is more preferably an aromatic ring such as benzene, fluorene, naphthalene, anthracene, phenanthrene, or biphenyl.

[0334] Rz 1 ~Rz 4 The ring structure (alicyclic hydrocarbon, aromatic hydrocarbon) formed by may have a substituent. The substituent here may be any of the above-mentioned Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4The substituents in the cyclic group of Rz (for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, a carbonyl group, etc.) are the same as those in the cyclic group of Rz. 1 ~Rz 4 From the viewpoint of compatibility with the component (A), the substituent in the ring structure formed by is preferably an alkyl group, a halogen atom, or a halogenated alkyl group.

[0335] Rz 1 ~Rz 4 The ring structure formed by two or more of the above is, among others, one side (Rz 1 and Rz 2 and the carbon atom to which Rz is bonded. 3 and Rz 4 A ring structure sharing a bond with the carbon atom to which is bonded is preferred, and an aromatic ring structure is more preferred.

[0336] In the formula (d0-an0), "when permitted by atomic valence" means as follows. That is, Rz 1 and Rz 2 and the carbon atom to which Rz is bonded. 3 and Rz 4 If the bond between the carbon atom and is a single bond, Rz 1 , Rz 2 , Rz 3 and Rz 4 All of the above are present. 1 and Rz 2 and the carbon atom to which Rz is bonded. 3 and Rz 4 If the bond between the carbon atom and is a double bond, Rz 1 or Rz 2 Only one of Rz exists 3 and Rz 4 Only one of these exists. For example, Rz 1 and Rz 3 When Rz is bonded to form an aromatic ring structure, 2 and Rz 4 does not exist.

[0337] In the above formula (d0-an0), Rx 1 ~Rx 4 Two or more of Rx may be bonded to each other to form a ring structure. For example, Rx 1 Rx 2 ~Rx 4 may form a ring structure with any of the above. Rx required 1 ~Rx 4 The ring structure formed by two or more of the above may be an alicyclic hydrocarbon or an aromatic hydrocarbon. In addition, this ring structure may be a polycyclic structure formed with other ring structures.

[0338] Rx 1 ~Rx 4 The alicyclic hydrocarbon formed by two or more of the above may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon, a monocycloalkane is preferable. As the monocycloalkane, one having 3 to 6 carbon atoms is preferable, specifically, cyclopentane, cyclohexane, etc. are mentioned. As the polycyclic alicyclic hydrocarbon, a polycycloalkane is preferable. As the polycycloalkane, one having 7 to 30 carbon atoms is preferable, specifically, a polycycloalkane having a crosslinked ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; and a polycycloalkane having a condensed ring polycyclic skeleton such as a cyclic group having a steroid skeleton is more preferable.

[0339] Rx 1 ~Rx 4 The aromatic hydrocarbon ring formed by two of the Rx groups includes benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are replaced with heteroatoms. 1 ~Rx 4 From the viewpoint of compatibility with the component (A), the aromatic hydrocarbon ring formed by two of these preferably does not contain a heteroatom, and is more preferably an aromatic ring such as benzene, fluorene, naphthalene, anthracene, phenanthrene, or biphenyl.

[0340] Rx 1 ~Rx 4 The ring structure (alicyclic hydrocarbon, aromatic hydrocarbon) formed by may have a substituent. The substituent here may be any of the above-mentioned Rx 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 The substituents in the cyclic group of Rx (for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, a carbonyl group, etc.) are the same as those in the cyclic group of Rx. 1 ~Rx 4 From the viewpoint of compatibility with the component (A), the substituent in the ring structure formed by is preferably an alkyl group, a halogen atom, or a halogenated alkyl group.

[0341] Rx 1 ~Rx 4 Among these, the ring structure formed by two or more of the above is preferably an alicyclic hydrocarbon. Also, Rx 1 ~Rx 4 The ring structure formed by two or more of Rx 1 ~Rx 2 At least one of the Rx 3 ~Rx 4 At least one of these is preferably bonded to each other to form a bridged ring structure, and more preferably this ring structure is an alicyclic hydrocarbon.

[0342] Said Rx 1 ~Rx 2 At least one of the Rx 3 ~Rx 4 and at least one of Ry bonded to each other to form a ring structure. 1 , Ry 2 , Rz 1 and Rz 2 , Rz 3 and Rz 4 The number of carbon atoms constituting the ring structure including the carbon atoms to which each of the carbon atoms is bonded is preferably 7 to 16.

[0343] In the above formula (d0-an0), Rx 1 ~Rx 4 2 or more, Ry 1 ~Ry 2 , or Rz 1 ~Rz 4 Two or more of these are bonded to each other to form an aromatic ring. The aromatic ring is the same as the aromatic ring explained in the above formula (d0).

[0344] In the above formula (d0-an0), Rx 1 ~Rx 4 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of Rx has an anion group represented by the general formula (d0-r-an1), and the entire anion portion is an n-valent anion. n is an integer of 1 or more. 1 ~Rx 4 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 may each be the anionic group. 1 ~Rx 4 When two or more of Ry are bonded to each other to form a ring structure, the carbon atom forming the ring structure or the hydrogen atom bonded to the carbon atom may be substituted with the anion group. 1 ~Ry 2 When two or more of Rz are bonded to each other to form a ring structure, the carbon atom forming the ring structure or the hydrogen atom bonded to the carbon atom may be substituted with the anion group. 1 ~Rz 4 When two or more of these are bonded to each other to form a ring structure, a carbon atom forming the ring structure or a hydrogen atom bonded to this carbon atom may be substituted with the anionic group.

[0345] In the above formula (d0-r-an1), Yd 0 The divalent linking group in the formula (d0) is 0 is the same as the divalent linking group in

[0346] The number of anionic groups in the component (D0) may be one, or two or more. The anion moiety of the component (D0) as a whole is an n-valent anion, where n is an integer of 1 or more, preferably 1 or 2, and more preferably 1.

[0347] In the above formula (d0-an0), Rx 1 ~Rx 4 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of the above has the acid-decomposable group. Preferred embodiments of the acid-decomposable group are the same as those described in the above formula (d0).

[0348] From the standpoint of inhibiting acid diffusion, the anion moiety in the component (D0) is more preferably an anion represented by the following general formula (d0-an1).

[0349] [ka] [In the formula, Rx 5 ~Rx 6 Each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom. 7 ~Rx 8 Each of Rx independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or may be bonded to each other to form a ring structure. p is 1 or 2, and when p=2, multiple Rx 7 ~Rx 8 may be different from each other. 1 ~Ry 2 each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or may be mutually bonded to form a ring structure. [ka] is a double bond or a single bond. 1 ~Rz 4Each independently represents a hydrocarbon group which may have a substituent, if the atomic valence allows, or a hydrogen atom, or two or more may be bonded together to form a ring structure. 5 ~Rx 6 , Rx 7 ~Rx 8 , Ry 1 ~Ry 2 , or Rz 1 ~Rz 4 Two or more of Rx are bonded to each other to form an aromatic ring. 5 ~Rx 8 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of Rx has an anion group represented by the following general formula (d0-r-an1), and the entire anion portion is an n-valent anion. 5 ~Rx 8 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of the groups has an acid-decomposable group. n is an integer of 1 or more.]

[0350] [ka] [Wherein, Yd 0 is a divalent linking group or a single bond. * indicates a bond.]

[0351] In the above formula (d0-an1), Rx 5 ~Rx 6 Each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom. 5 ~Rx 6 The hydrocarbon group which may have a substituent is Rx in the above-mentioned formula (d0-an0). 1 ~Rx 4 The same applies to the optionally substituted hydrocarbon group in the above.

[0352] In the above formula (d0-an1), Rx 7 ~Rx 8Each of Rx independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or may be bonded to each other to form a ring structure. 7 ~Rx 8 is Rx in the above formula (d0-an0) 1 ~Rx 4 This is similar to the explanation for

[0353] In the formula (d0-an1), p is 1 or 2, and when p=2, a plurality of Rx 7 ~Rx 8 may be different from each other. In the anion represented by the general formula (d0-an1), when p=1, it has a bicycloheptane ring structure, and when p=2, it has a bicyclooctane ring structure.

[0354] In the above formula (d0-an1), Ry 1 ~Ry 2 Each of Ry independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or may be bonded to each other to form a ring structure. 1 ~Ry 2 is Ry in the above formula (d0-an0) 1 ~Ry 2 is the same as: Rz 1 ~Rz 4 Each of Rz independently represents a hydrocarbon group which may have a substituent, if the atomic valence allows, or a hydrogen atom, or two or more of Rz may be bonded to each other to form a ring structure. 1 ~Rz 4 is Rz in the above formula (d0-an0) 1 ~Rz 4 is the same as:

[0355] In the above formula (d0-an1), Rx 5 ~Rx 6 , Rx 7 ~Rx 8 , Ry 1 ~Ry 2 , or Rz 1 ~Rz 4Two or more of these are bonded to each other to form an aromatic ring. The aromatic ring is the same as that explained in the above formula (d0).

[0356] In the above formula (d0-an1), Rx 5 ~Rx 8 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of the anionic groups has the above formula (d0-r-an1), and the entire anionic portion forms an n-valent anion. n is an integer of 1 or more, preferably 1 or 2, and more preferably 1.

[0357] In the above formula (d0-an1), Rx 5 ~Rx 8 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of the above has an acid-decomposable group. Preferred embodiments of the acid-decomposable group are the same as those described in the above formula (d0).

[0358] Among the above, the anion moiety in the component (D0) is more preferably an anion represented by p=2 in the above formula (d0-an1), that is, an anion represented by the following general formula (d0-an2).

[0359] [ka] [In the formula, Rx 5 ~Rx 6 Each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom. 7 ~Rx 8 Ry each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or two or more of them may be bonded to each other to form a ring structure. 1 ~Ry 2 each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or may be mutually bonded to form a ring structure. [ka] is a double bond or a single bond. 1 ~Rz 4 Each independently represents a hydrocarbon group which may have a substituent, if the atomic valence allows, or a hydrogen atom, or two or more may be bonded together to form a ring structure. 5 ~Rx 6 , Rx 7 ~Rx 8 2 or more, Ry 1 ~Ry 2 , or Rz 1 ~Rz 4 Two or more of Rx are bonded to each other to form an aromatic ring. 5 ~Rx 8 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of Rx has an anion group represented by the following general formula (d0-r-an1), and the entire anion portion is an n-valent anion. 5 ~Rx 8 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of the groups has an acid-decomposable group. n is an integer of 1 or more.]

[0360] [ka] [Wherein, Yd 0 is a divalent linking group or a single bond. * indicates a bond.]

[0361] In the above formula (d0-an2), Rx 5 ~Rx 6 , Rx 7 ~Rx 8 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 is Rx in the above formula (d0-an1) 5 ~Rx 6 , Rx7 ~Rx 8 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 and the same as above.

[0362] In the above formula (d0-an2), Rx 5 ~Rx 6 , Rx 7 ~Rx 8 2 or more, Ry 1 ~Ry 2 , or Rz 1 ~Rz 4 Two or more of these are bonded to each other to form an aromatic ring. The aromatic ring is the same as that explained in the above formula (d0).

[0363] In the above formula (d0-an2), Rx 5 ~Rx 8 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of the anion groups has the above formula (d0-r-an1), and the entire anion portion forms an n-valent anion. n is an integer of 1 or more, preferably 1 or 2, and more preferably 1.

[0364] In the above formula (d0-an2), Rx 5 ~Rx 8 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of the above has the above-mentioned acid-decomposable group. Preferred embodiments of the acid-decomposable group are the same as those described in the above formula (d0).

[0365] In the above formula (d0-an0), formula (d0-an1), and formula (d0-an2), Ry 1 ~Ry 2 are preferably bonded to each other to form a ring structure, and the ring structure formed is more preferably an aromatic hydrocarbon (aromatic ring, aromatic heterocycle) which may have a substituent.

[0366] In the above formula (d0-an0), formula (d0-an1), and formula (d0-an2), Rz 1 ~Rz 4 are preferably bonded to each other to form a ring structure, and the ring structure formed is such that one side (Rz 1 and Rz 2 and the carbon atom to which Rz is bonded. 3 and Rz 4 Preferably, the ring structure shares a bond with the carbon atom to which the carbon atom is bonded, and more preferably, an aromatic hydrocarbon (aromatic ring, aromatic heterocycle) which may have a substituent.

[0367] In the above formula (d0-an1) and formula (d0-an2), Rx 7 ~Rx 8 are preferably bonded to each other to form a ring structure, and the ring structure formed is more preferably an aromatic hydrocarbon (aromatic ring, aromatic heterocycle) which may have a substituent. In the above formula (d0-an2), Rx 7 ~Rx 8 The ring structure formed in the formula is one side of the six-membered ring (Rx 7 and Rx 8 A ring structure sharing a bond between the same carbon atoms to which is bonded is preferred, and an aromatic hydrocarbon (aromatic ring, aromatic heterocycle) which may have a substituent is more preferred.

[0368] The entire anion represented by the formula (d0-an2) is Rx 7 ~Rx 8 , Ry 1 ~Ry 2 , Rz 1 ~Rz 4 In each of the above, the number of ring structures formed by bonding to each other may be one or more, and is preferably two or three.

[0369] In this embodiment, from the viewpoint of improving CDU and resolution, the anion moiety of the component (D0) is particularly preferably an anion represented by the following general formula (d0-an3).

[0370] [ka] [In the formula, Rx 5 ~Rx 6 each independently represents a hydrocarbon group which may have a substituent, or a hydrogen atom. [ka] is a double bond or a single bond. 1 ~Rz 4 Each independently represents a hydrocarbon group which may have a substituent, if the atomic valence allows, or a hydrogen atom, or two or more may be bonded together to form a ring structure. 5 ~Rx 6 and Rz 1 ~Rz 4 At least one of Rx has an anionic group represented by the following general formula (d0-r-an1), and the entire anionic portion forms an n-valent anion, where n is an integer of 1 or more. 5 ~Rx 6 and Rz 1 ~Rz 4 At least one of R has an acid-decomposable group. 021 is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, or a nitro group. n1 is an integer of 1 to 3. n11 is an integer of 0 to 8. R 022 is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, or a nitro group. n2 is an integer of 1 to 3. n21 is an integer of 0 to 8.]

[0371] [ka] [Wherein, Yd 0 is a divalent linking group or a single bond. * indicates a bond.]

[0372] In the above formula (d0-an3), Rx 5 ~Rx 6 , Rz 1 ~Rz 4 is Rx in the formula (d0-an1) 5 ~Rx6 , Rz 1 ~Rz 4 and the same as above.

[0373] In the above formula (d0-an3), R 021 is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, a carbonyl group, or a nitro group. R 021 The alkyl group in 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. R 021 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group, and further preferably a methoxy group or an ethoxy group. R 021 As the halogen atom in, a fluorine atom is preferable. R 021 In the above formula, examples of the halogenated alkyl group 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 halogen atoms. Among them, R 021 From the viewpoint of compatibility with the component (A), an alkyl group, a halogen atom, or a halogenated alkyl group is preferred.

[0374] In the above formula (d0-an3), n1 represents an integer of 1 to 3, preferably 1 or 2, and more preferably 1. In the above formula (d0-an3), n11 represents an integer of 0 to 8, preferably an integer of 0 to 4, more preferably 0, 1 or 2, and further preferably 0 or 1.

[0375] In the above formula (d0-an3), R 022 is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, a carbonyl group, or a nitro group, each of which is defined as R021 Among them, R 022 From the viewpoint of compatibility with the component (A), an alkyl group, a halogen atom, or a halogenated alkyl group is preferred. In the above formula (d0-an3), n2 represents an integer of 1 to 3, preferably 1 or 2, and particularly preferably 1. In the above formula (d0-an3), n21 represents an integer of 0 to 8, preferably an integer of 0 to 4, more preferably 0, 1 or 2, and particularly preferably 0 or 1.

[0376] In the above formula (d0-an3), Rx 5 ~Rx 6 and Rz 1 ~Rz 4 At least one of the anion groups has the above formula (d0-r-an1), and the entire anion portion forms an n-valent anion. n is an integer of 1 or more, preferably 1 or 2, and more preferably 1.

[0377] In the above formula (d0-an3), Rx 5 ~Rx 6 and Rz 1 ~Rz 4 At least one of the above has the acid-decomposable group. Preferred embodiments of the acid-decomposable group are the same as those described in the above formula (d0).

[0378] Among the above formulas (d0-an0), (d0-an1), (d0-an2), and (d0-an3), the above Rz 1 ~Rz 4 At least one of the Rz has an anionic group. 1 ~Rz 4 When two or more of these are bonded to each other to form a ring structure, a carbon atom forming the ring structure or a hydrogen atom bonded to this carbon atom may be substituted with the anionic group.

[0379] Among the formulas (d0-an0), (d0-an1), (d0-an2), and (d0-an3), the Rz 1 ~Rz 4 At least one of the Rz has an acid-decomposable group. 1 ~Rz 4 When two or more of these are bonded to each other to form a ring structure, a hydrogen atom bonded to a carbon atom forming the ring structure may be substituted with the acid-decomposable group.

[0380] Specific examples of the anion moiety of the component (D0) are shown below.

[0381] [ka]

[0382] [ka]

[0383] [ka]

[0384] As the anion portion of the (D0) component, among the above, anions represented by any one of the chemical formulas (d0-an-1) to (d0-an-21) are preferred, anions represented by any one of the chemical formulas (d0-an-1) to (d0-an-15) are more preferred, and anions represented by any one of the chemical formulas (d0-an-1) to (d0-an-3), (d0-an-8), (d0-an-9), (d0-an-12), (d0-an-14), and (d0-an-15) are even more preferred.

[0385] {Cation part of component (D0)} In the above general formula (d0), M m+ represents an organic cation having a valence of m. Among these, sulfonium cation and iodonium cation are preferred. m is an integer of 1 or greater.

[0386] M m+ Suitable examples of the organic cation include the same cations represented by the general formulas (ca-1) to (ca-5) above, and the cation represented by the general formula (ca-1) above is more preferred.

[0387] In the resist composition of this embodiment, the component (D0) is preferably a compound represented by general formula (d0-1) below, from among the above.

[0388] [ka] [In the formula, Rx 1 ~Rx 4 Ry each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or two or more of them may be bonded to each other to form a ring structure. 1 ~Ry 2 each independently represents a hydrocarbon group which may have a substituent or a hydrogen atom, or may be mutually bonded to form a ring structure. [ka] is a double bond or a single bond. 1 ~Rz 4 Each independently represents a hydrocarbon group which may have a substituent, if the atomic valence allows, or a hydrogen atom, or two or more may be bonded together to form a ring structure. 1 ~Rx 4 2 or more, Ry 1 ~Ry 2 , or Rz 1 ~Rz 4 At least one of two or more of Rx is bonded to each other to form an aromatic ring. 1 ~Rx 4 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4At least one of Rx has an anion group represented by the following general formula (d0-r-an1), and the entire anion portion is an n-valent anion. 1 ~Rx 4 , Ry 1 ~Ry 2 and Rz 1 ~Rz 4 At least one of the groups has the acid-decomposable group. n is an integer of 1 or more. m is an integer of 1 or more, and M m+ represents an organic cation having a valence of m.

[0389] [ka] [Wherein, Yd 0 is a divalent linking group or a single bond. * indicates a bond.]

[0390] The anion portion of the compound represented by the above general formula (d0-1) is the same as the anion represented by the above general formula (d0-an0).

[0391] The acid decomposable group of the anion part of the compound represented by the general formula (d0-1) is preferably an acid decomposable group represented by the general formula (pg-1). Rpg in the acid decomposable group represented by the general formula (pg-1) preferably has a cyclic acid dissociable group, more preferably an acid dissociable group represented by any one of the general formulas (pg-r-1) to (pg-r-3), and even more preferably an acid dissociable group represented by the general formula (pg-r-1). More specifically, Rpg is preferably an acid dissociable group represented by general formula (a1-r2-1).

[0392] Yd in the above general formula (d0-r-an1) 0 As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, and a linking group represented by the above general formula (y-d0-1) or (y-d0-2) is more preferable.

[0393] The cationic moiety of the compound represented by the above general formula (d0-1) is the same as the cationic moiety of the compound represented by the above general formula (d0).

[0394] Specific examples of the component (D0) include, but are not limited to, the following:

[0395] [ka]

[0396] [ka]

[0397] In the resist composition of this embodiment, the component (D0) may be used either as a single type, or in a combination of two or more types. In the resist composition of this embodiment, the content of the component (D0) relative to 100 parts by mass of the component (A) is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 3 to 10 parts by mass. When the amount of the component (D0) is at least as large as the lower limit of the above preferred range, CDU and resolution are further improved during resist pattern formation, while when the amount is at most the upper limit of the preferred range, better sensitivity can be maintained.

[0398] The component (D) in the resist composition of this embodiment may contain a base component other than the above-mentioned component (D0). Examples of the base component other than the component (D0) include a photodecomposable base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure to light 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).

[0399] 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 ability (basicity), but they act as quenchers in the unexposed areas of the resist film.

[0400] [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 the formula, 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 organic cation having a valence of m.

[0401] {(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, each of which is represented by the R' 201 The same can be mentioned. Among these, Rd 1is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1) to (a2-r-7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the above formulas (y-al-1) to (y-al-5). Note that Rd 1 In the case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the formula (d3-1) has a linking group represented by the above general formulas (y-al-1) to (y-al-7) as a substituent, in the above 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 above formula (y-al-1) to (y-al-7) is bonded to V' 101 It is. 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. Specific examples of the chain alkyl group include linear 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 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.

[0402] When the chain 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 further preferably 1 to 4. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atom other than a fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0403] Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

[0404] [ka]

[0405] ··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 formulas (ca-1) to (ca-5) above, more preferably those represented by the general formula (ca-1), and even more preferably those represented by the general formulas (ca-1-1) to (ca-1-72). The component (d1-1) may be used alone or in combination of two or more.

[0406] {(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 the R' 201 The same can be mentioned. However, Rd 2In the above, the carbon atom adjacent to the S atom does not have a fluorine atom bonded thereto (is not substituted with fluorine), and this makes the anion of the (d1-2) component an appropriate weak acid anion, thereby improving the quenching ability of the (D) component. Rd 2 As the alkyl group, a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent is preferable, and an aliphatic cyclic group which may have a substituent is more preferable.

[0407] The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably has 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.

[0408] Rd 2 The hydrocarbon group may have a substituent, and examples of the substituent include Rd 1 Examples of the substituent include the same as the substituents that may be possessed by the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0409] Of the above, the anion moiety of the component (d1-2) is preferably a camphorsulfonate anion.

[0410] Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

[0411] [ka]

[0412] ··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.

[0413] {Component (d1-3)} 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 R' 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 More preferred are the same fluorinated alkyl groups as those mentioned above.

[0414] 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 the R' 201 The same can be mentioned. Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group, which may have a substituent, is preferable. Rd 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. 4 A part of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Rd 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.

[0415] Rd 4 The alkenyl group in R' 201Examples of the alkenyl group include the same as the alkenyl group in the above, and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group 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.

[0416] Rd 4 The cyclic group in R' 201 Examples of the cyclic groups include those similar to those in the above formula, 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, and the lithography properties become good. 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.

[0417] 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 group which may have a substituent and the divalent linking group containing a hetero atom as 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.

[0418] Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

[0419] [ka]

[0420] [ka]

[0421] ··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.

[0422] The component (D1) may be any one of the above components (d1-1) to (d1-3), or a combination of two or more of them. When the resist composition contains the component (D1), the amount of the component (D1) in the resist composition is preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the component (A1). When the amount of the component (D1) is at least as large as the preferred lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained, while when it is no more than the upper limit, good sensitivity can be maintained and excellent throughput is also achieved.

[0423] 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 the component (d1-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0424] 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 above-mentioned component (D1). The component (D2) is not particularly limited as long as it acts as an acid diffusion control agent 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 more preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 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), or cyclic amines. Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0425] 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.

[0426] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, and the like, with triethanolamine triacetate being preferred.

[0427] 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, and N-tert-butoxycarbonylpyrrolidine.

[0428] Of the above, the component (D2) is preferably an alkylamine, and more preferably a trialkylamine having 5 to 10 carbon atoms.

[0429] The component (D2) may be used alone or in combination of two or more types. When the resist composition contains the component (D2), the amount of the component (D2) in the resist composition is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the component (A1). When the amount of the component (D2) is at least as large as the preferred lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained, while when it is no more than the upper limit, good sensitivity can be maintained and excellent throughput is also achieved.

[0430] Of the entire component (D) contained in the resist composition of this embodiment, the content of the component (D0) is preferably 50 mass% or more, more preferably 70 mass% or more, and even more preferably 90 mass% or more. The component (D) may consist solely of the component (D0).

[0431] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the above-mentioned components (A), (B), and (D). Examples of other components include the following components (E), (F), and (S).

[0432] <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 oxoacids and derivatives thereof (hereafter referred to as "component (E)") for the purposes of preventing deterioration of sensitivity and improving the resist pattern shape and stability over time after exposure. Specific examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, and among these, salicylic acid is preferred. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred. Examples of derivatives of phosphorus oxoacids include esters in which the hydrogen atoms of the above oxoacids are substituted with hydrocarbon groups. Examples of the hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of the derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphoric acid ester and diphenyl phosphoric acid ester. Examples of the derivatives of phosphonic acid include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid.

[0433] In the resist composition of this embodiment, the component (E) may use either a single type, or a combination of two or more types. When the resist composition contains the component (E), the amount of the component (E) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the component (A). By setting the amount in this range, the lithography properties are further improved.

[0434] <Fluorine additive component (F)> The resist composition of this embodiment may contain a fluorine additive component (hereafter referred to as “component (F)”) in order to impart water repellency to the resist film or to improve lithography properties. As the component (F), for example, fluorine-containing polymeric compounds described in JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226 can be used. More specifically, the component (F) may be a polymer having a structural unit (f1) represented by the following general formula (f1-1). The polymer may be a polymer (homopolymer) consisting of only the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1); a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1), and more preferably a copolymer of the structural unit (f1) and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, or a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate, and more preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate.

[0435] [ka] [In the formula, R is the same as above, and Rf 102 and Rf 103 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Rf 102 and Rf 103 may be the same or different. 1 is an integer from 0 to 5, and Rf 101 is an organic group containing a fluorine atom.

[0436] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as defined above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf 102 and Rf 103 The halogen atom in Rf is preferably a fluorine atom. 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms in R include the same alkyl groups having 1 to 5 carbon atoms as those in R, and a methyl group or an ethyl group is preferred. 102 and Rf103 Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms include groups in which part or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is preferred. Among these, Rf 102 and Rf 103 is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and further preferably a hydrogen atom. In formula (f1-1), nf 1 represents an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0437] In formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The fluorine atom-containing hydrocarbon group may be linear, branched or cyclic and preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and particularly preferably has 1 to 10 carbon atoms. Furthermore, in the hydrocarbon group containing fluorine atoms, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more are fluorinated, as this enhances the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101 is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, or -CH2-CH2-CF2-CF2-CF2-CF3.

[0438] The weight average molecular weight (Mw) of component (F) (based on polystyrene conversion by gel permeation chromatography) is preferably 1000 to 50000, more preferably 5000 to 40000, and most preferably 10000 to 30000. When it is below the upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is above the lower limit of this range, the resist film has good water repellency. The dispersity (Mw / Mn) of the component (F) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and most preferably from 1.0 to 2.5.

[0439] In the resist composition of this embodiment, the component (F) may use either a single type, or a combination of two or more types. When the resist composition contains the component (F), the amount of the component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the component (A).

[0440] <Organic solvent component (S)> The resist composition of this embodiment can be produced by dissolving the resist materials in an organic solvent component (hereafter referred to as “component (S)”). The component (S) can be any solvent that is capable of dissolving the individual components used to form a homogeneous solution, and any solvent can be appropriately selected from those known in the art as a solvent for chemically amplified resist compositions. Examples of the (S) component include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; and compounds having an ether bond such as monoalkyl ethers, monoethyl ethers, monopropyl ethers, and monobutyl ethers of the above-mentioned polyhydric alcohols or compounds having an ester bond, or monophenyl ethers. derivatives of polyhydric alcohols (among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred); cyclic ethers such as dioxane, esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, the component (S) may be used alone or as a mixed solvent of two or more kinds. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0441] As the component (S), a mixed solvent of PGMEA and a polar solvent is also preferred. The blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and the polar solvent, and is preferably within the range of 1:9 to 9:1, and more preferably 2:8 to 8:2. More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is blended as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. As the component (S), a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone is also preferred. In this case, the mixing ratio of the former to the latter is preferably 70:30 to 95:5 by mass. The amount of the component (S) used is not particularly limited, and is set appropriately depending on the coating film thickness at a concentration that allows application to a substrate, etc. In general, 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 %.

[0442] The resist composition of the present embodiment may further contain, if desired, compatible additives such as an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, or a dye.

[0443] In the resist composition of this embodiment, after dissolving the resist material in the component (S), impurities and the like may be removed using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous film, a filter made of a polyamideimide porous film, or a filter made of a polyimide porous film and a polyamideimide porous film. Examples of the polyimide porous film and the polyamideimide porous film include those described in JP 2016-155121 A.

[0444] The resist composition of this embodiment described above contains a compound (D0) (component (D0)) represented by general formula (d0). The anion moiety of component (D0) has a specific bulky structure (a fused ring group containing a fused ring that contains one or more aromatic rings), which increases the uniformity of component (D0) within the resist film, and allows the acid generated from component (B) to be trapped evenly by component (D0) at the boundary between exposed and unexposed areas of the resist film. In addition, the acid-decomposable group of the anion moiety of component (D0) is eliminated in the exposed area of ​​the resist film to generate a polar group, which reduces the hydrophobicity of component (D0) and improves the affinity of component (D0) with the developer (alkaline developer). It is therefore presumed that the resist composition of this embodiment, which contains the component (D0), is capable of forming a resist pattern with excellent CDU and resolution.

[0445] (Method of 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 method for forming a resist pattern is, for example, a method for forming a resist pattern carried out as follows.

[0446] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and then baked (post-applied 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 lithography using 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.

[0447] 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, a rinse liquid containing an organic solvent is preferably used. In the case of a solvent development process, after the development treatment or rinsing treatment, a treatment may be carried out in which the developer or rinsing liquid adhering to the pattern is removed by using a supercritical fluid. After the development treatment or rinsing treatment, drying is performed. In some cases, a baking treatment (post-baking) may be performed after the development treatment. In this manner, a resist pattern can be formed.

[0448] The support is not particularly limited, and may be a conventionally known support, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern is formed. More specifically, it may be a silicon wafer, a substrate made of metal such as copper, chromium, iron, or aluminum, or a glass substrate. As the material for the wiring pattern, for example, copper, aluminum, nickel, or gold may be used. The support may be a substrate as described above on which an inorganic and / or organic film is provided. Examples of inorganic films include inorganic anti-reflective coatings (inorganic BARC). Examples of organic films include organic anti-reflective coatings (organic BARC) and organic films such as lower organic films in a multi-layer resist method. Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the lower organic film is patterned using the resist pattern formed on the upper resist film as a mask, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be made thin, and a fine pattern with a high aspect ratio can be formed. Multilayer resist methods are basically divided into a two-layer structure consisting of an upper resist film and a lower organic film (two-layer resist method), and a three-layer structure consisting of three or more layers with one or more intermediate layers (such as a thin metal film) provided between the upper resist film and the lower organic film (three-layer resist method).

[0449] 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-ray, and soft X-ray can be used. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB, or EUV, more useful for ArF excimer laser, EB, or EUV, and particularly useful for EB or EUV. That is, the resist pattern forming method of this embodiment is a particularly useful method when the step of exposing the resist film includes an operation of exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam).

[0450] The exposure method for the resist film may be a normal exposure method (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography, with liquid immersion lithography being preferred. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure tool 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 larger than that of air and smaller than that of the resist film to be exposed. The refractive index of the solvent is not particularly limited as long as it is within the above range. Examples of the solvent having a refractive index larger than that of air and smaller than that of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent. Specific examples of the fluorine-based inert liquid include liquids mainly composed of fluorine-based compounds such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, and C5H3F7, and preferably have a boiling point of 70 to 180° C., more preferably 80 to 160° C. If the fluorine-based inert liquid has a boiling point in the above range, it is preferable because the medium used for immersion can be removed in a simple manner after exposure is completed. As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are replaced with fluorine atoms is particularly preferred. Specific examples of the perfluoroalkyl compound include perfluoroalkyl ether compounds and perfluoroalkylamine compounds. More specifically, the perfluoroalkyl ether compound may be perfluoro(2-butyl-tetrahydrofuran) (boiling point 102°C), and the perfluoroalkylamine compound may be perfluorotributylamine (boiling point 174°C). As the liquid immersion medium, water is preferably used from the viewpoints of cost, safety, environmental issues, versatility, and the like.

[0451] An example of an alkaline developer used in the development treatment in the alkaline development process is 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 the component (A) (the component (A) before exposure), and may be appropriately selected from known organic solvents. Specific examples of the organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and hydrocarbon solvents. Ketone-based solvents are organic solvents that contain CC(=O)-C in their structure. Ester-based solvents are organic solvents that contain CC(=O)-OC in their structure. Alcohol-based solvents are organic solvents that contain an alcoholic hydroxyl group in their structure. "Alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile-based solvents are organic solvents that contain a nitrile group in their structure. Amide-based solvents are organic solvents that contain an amide group in their structure. Ether-based solvents are organic solvents that contain COC in their structure. Some organic solvents contain multiple types of functional groups that characterize the above-mentioned solvents in their structures, and in such cases, the organic solvent is considered to fall under any of the solvent types that contain the functional groups possessed by the organic solvent. For example, diethylene glycol monomethyl ether is considered to fall under both the alcohol-based solvents and the ether-based solvents in the above classification. The hydrocarbon solvent is a hydrocarbon solvent that is composed of a hydrocarbon that may be halogenated and has no substituents other than halogen atoms. The halogen atom is preferably a fluorine atom. Of the above, the organic solvent contained in the organic developer is preferably a polar solvent, and more preferably a ketone solvent, an ester solvent, a nitrile solvent, or the like.

[0452] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), etc. Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

[0453] Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxyethyl acetate, ethoxyethyl acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, propylene glycol monoethyl ether acetate, propylene glycol monoethyl ether acetate, 2-ethoxybutyl ... dibutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, proline lactate Examples of the ester-based solvent include pyru, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, etc. Among these, butyl acetate is preferred as the ester-based solvent.

[0454] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0455] The organic developer may contain known additives as necessary. Examples of such additives include surfactants. The surfactant is not particularly limited, but may be, for example, an ionic or nonionic fluorine-based and / or silicon-based surfactant. The surfactant is preferably a nonionic surfactant, more preferably a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant. When a surfactant is added, the amount added is usually from 0.001 to 5 mass %, preferably from 0.005 to 2 mass %, and more preferably from 0.01 to 0.5 mass %, based on the total amount of the organic developer.

[0456] 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 there for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), and 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).

[0457] The organic solvent contained in the rinse solution used in the rinse treatment after the development treatment in the solvent development process can be selected appropriately from the organic solvents listed as the organic solvents used in the organic developer, and can be used if it is difficult to dissolve the resist pattern.Usually, at least one solvent selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent is used.Among these, at least one solvent selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, and an amide solvent is preferred, at least one solvent selected from an alcohol solvent and an ester solvent is more preferred, and an alcohol solvent is particularly preferred. The alcohol-based solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be any of linear, branched, and cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred. These organic solvents may be used alone or in combination of two or more. They may also be used in combination with other organic solvents or water. However, in consideration of development characteristics, the amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less, based on the total amount of the rinse solution. The rinse solution may contain known additives as necessary. Examples of such additives include surfactants. The surfactants include those similar to those described above, and nonionic surfactants are preferred, and nonionic fluorine-based surfactants or nonionic silicon-based surfactants are more preferred. When a surfactant is added, the amount of the surfactant added is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the rinse liquid.

[0458] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously applying the rinse liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), or a method of spraying the rinse liquid onto the surface of the support (spray method).

[0459] According to the method of forming a resist pattern of the present embodiment described above, since the resist composition described above is used, a resist pattern with excellent CDU and resolution can be formed.

[0460] (compound) The compound according to the third aspect of the present invention is a compound represented by the following general formula (d0).

[0461] [ka] [In the formula, Rd 0 is a fused ring group containing one or more fused rings each having an aromatic ring. The fused ring group has, as a substituent, an acid-decomposable group that is decomposed by the action of an acid to generate a polar group. 0 is a divalent linking group or a single bond. m+ represents an organic cation having a valence of m, where m is an integer of 1 or more.

[0462] The compound represented by the above general formula (d0) is the same as the component (D0) in the resist composition related to the first aspect of the present invention.

[0463] [Method for producing the compound represented by formula (d0)] The component (D0) can be produced by a known method. As a specific method for producing the component (D0), a method for producing a compound represented by general formula (d'0), which is an example of the component (D0), is shown below.

[0464] First, a compound X1 represented by the following general formula (X-1) is reacted with a compound (Alc-1) represented by the following general formula (Alc-1) having a desired acid dissociable group (Rpg) to obtain a compound (D0pre) represented by the following general formula (D0pre) (Step 1). Next, compound (D0pre) and compound (S-1) represented by the following general formula (S-1) are subjected to a salt exchange reaction in the presence of a base to obtain a compound represented by general formula (d'0), which is an example of the (D0) component (second step). In the following reaction formula, for convenience, "RpgO-C=O-Rd 00 ", but "RpgO-C=O-Rd 00 " is "Rd 0 " is an example.

[0465] [ka] [In the formula, Rd 00 is a fused ring group containing a fused ring containing one or more aromatic rings. Rpg is an acid dissociable group represented by the above general formula (pg-r-1), an acid dissociable group represented by the general formula (pg-r-2), an acid dissociable group represented by the general formula (pg-r-3), or an acid dissociable group represented by the general formula (pg-r-4). Z - is a halogen ion. (M m+ ) 1 / m represents an organic cation having a valence of m, where m is an integer of 1 or more.

[0466] 1st step: The first step is, for example, a step in which compound (X-1) and compound (Alc-1) are dissolved in an organic solvent (such as THF) and reacted in the presence of a base to obtain compound (D0pre).

[0467] Specific examples of the base include sodium hydride, K2CO3, Cs2CO3, lithium diisopropylamide (LDA), triethylamine, 4-dimethylaminopyridine, and the like. The reaction temperature is, for example, 0 to 50° C., and the reaction time is, for example, 10 minutes or more and 24 hours or less.

[0468] In the above formula, Rd 00 is a fused ring group containing one or more aromatic rings, and Rd in the above general formula (d0) 0 The fused ring group containing one or more fused rings having aromatic rings is the same as the fused ring group containing one or more fused rings having aromatic rings.

[0469] Second step: The second step is, for example, a step in which compound (D0pre) is reacted with a compound (S-1) for salt exchange in the presence of a solvent such as water, dichloromethane, acetonitrile, or chloroform, and a base, to obtain a compound represented by general formula (d'0), which is an example of the (D0) component.

[0470] Specific examples of the base include sodium hydride, K2CO3, Cs2CO3, lithium diisopropylamide (LDA), triethylamine, 4-dimethylaminopyridine, and the like.

[0471] In the above formula, Z - Specific examples of the ions include bromide ions and chloride ions. The reaction temperature is, for example, 0 to 100° C., and the reaction time is, for example, 10 minutes or more and 24 hours or less.

[0472] In the above formula, (M m+ ) 1 / m is (M m+ ) 1 / m is equivalent to.

[0473] After the salt exchange reaction is completed, the compound in the reaction solution may be isolated and purified. For the isolation and purification, a conventionally known method can be used, and for example, a suitable combination of concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used. The structure of the compound obtained as above is 1 H-nuclear magnetic resonance (NMR) spectroscopy, 13 C-NMR spectroscopy, 19 Identification can be achieved by common organic analysis methods such as F-NMR spectroscopy, infrared absorption (IR) spectroscopy, mass spectrometry (MS), elemental analysis, and X-ray crystal diffraction.

[0474] The method for producing the component (D0) may include, between the first step and the second step, a step of reacting compound (D0pre) with a hydroxy acid to obtain a compound represented by the above general formula (D0pre) different from compound (D0pre). Specific examples of the hydroxy acid include a compound represented by the following chemical formula (K-1) and a compound represented by the following chemical formula (K-2).

[0475] [ka]

[0476] The method for producing the component (D0) may also include a step of reacting the compound (D0pre) obtained in the first step above with a diol such as ethylene glycol to obtain an intermediate, and reacting the obtained intermediate with a dicarboxylic acid such as oxalic acid to obtain a compound represented by the above general formula (D0pre) which is different from compound (D0pre).

[0477] The raw materials used in each step may be commercially available or may be synthesized. For example, in the case of synthesizing compound (X-1), compound (X-1) can be obtained by carrying out a Diels-Alder reaction between an aromatic compound (e.g., anthracene) and an alkene (e.g., maleic anhydride).

[0478] The compound related to the third aspect of the present invention as explained above is a compound that is useful as an acid diffusion controller in the resist composition related to the first aspect of the present invention.

[0479] (Acid diffusion control agent) The acid diffusion controller according to the fourth aspect of the present invention comprises the compound according to the third aspect described above. Such an acid diffusion controller is useful as an acid diffusion controller for a chemically amplified resist composition. The compound related to the third aspect described above has a carboxylate anion in the anion moiety, and therefore generates, upon exposure, a weaker acid than, for example, a fluorinated alkylsulfonate anion in the anion moiety of an acid generator that is generally used in a chemically amplified resist composition. By using such an acid diffusion controller in a chemically amplified resist composition, the CDU and resolution performance are further improved in resist pattern formation.By using such an acid generator component, the CDU and resolution performance are further improved, particularly in resist pattern formation using an EB or EUV light source. EXAMPLES

[0480] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In this example, the compound represented by the chemical formula (X-1-1) is referred to as "compound (X-1-1)", and compounds represented by other chemical formulas are similarly referred to.

[0481] <Production of compound (X-1)> (Production Example 1-1) Anthracene (20.0 g, 112.2 mmol), maleic anhydride (16.6 g, 168.3 mmol), aluminum chloride (1.50 g, 11.2 mmol), and toluene (200 g) were added to a 300 mL three-neck flask, and the mixture was reacted at 80° C. for 4 hours under stirring. After cooling, ultrapure water (155 g) was added, and the mixture was stirred for 30 minutes, after which the precipitated solid was filtered. The residue was dissolved again in a mixed solvent of THF (93 g) and methylene chloride (680 g), washed three times with ultrapure water (155 g), and the organic layer was concentrated using a rotary evaporator. The concentrate was recrystallized with ethyl acetate to obtain compound (X-1-1).

[0482] [ka]

[0483] (Production Example 1-2) Compound (X-1-2) was obtained in the same manner as in the production example of compound (X-1-2), except that anthracene (20.0 g, 112.2 mmol) was changed to 2,3,6,7-tetramethylanthracene (26.3 g, 108.6 mmol).

[0484] [ka]

[0485] <Production of compound (D0pre)> (Production Example 2-1) A 500mL three-neck flask was charged with a 1.06M THF / hexane solution (87mL, 92.3mmol) of lithium diisopropylamide (LDA), cooled to 5°C, and then charged with 1-methylcyclopentanol (10.9g, 108.6mmol) dissolved in THF (30g), and reacted at 5°C or less for 2 hours. Then, compound (X1-1) (15.0g, 54.3mmol) dissolved in THF (225g) was charged, and reacted at 5°C or less for 2 hours. The reaction solution was charged into ultrapure water (205g) over 30 minutes, and then diheptane (205g) was added, and the mixture was stirred for 30 minutes, after which the organic layer was removed. The aqueous layer was washed three times with heptane (100 g), and then tert-butyl methyl ether (MTBE) (150 g) and 10% aqueous citric acid solution (205 g, 106.1 mmol) were added. After stirring for 30 minutes, the aqueous layer was removed. The collected organic layer was washed three times with ultrapure water (150 g), and the organic layer was concentrated using a rotary evaporator. The concentrate was recrystallized with ethyl acetate to obtain compound (D0pre-01).

[0486] [ka]

[0487] (Production Example 2-2) Compound (D0pre-08) was obtained in the same manner as in the production example of compound (D0pre-01), except that compound (X-1-1) (15.0 g, 54.3 mmol) was changed to compound (X-1-2) (18.1 g, 54.3 mmol).

[0488] [ka]

[0489] (Production Example 2-3) Compound (D0pre-06) was obtained in the same manner as in the production example of compound (D0pre-01), except that 1-methylcyclopentanol (10.9 g, 108.6 mmol) was changed to t-butyl alcohol (8.0 g, 108.6 mmol).

[0490] [ka]

[0491] (Production Example 2-4) Compound (D0pre-07) was obtained in the same manner as in the production example for compound (D0pre-01), except that 1-methylcyclopentanol (10.9 g, 108.6 mmol) was changed to 2-methyl-2-adamantanol (18.1 g, 108.6 mmol).

[0492] [ka]

[0493] (Production Example 2-5) Compound (D0pre-01) (11.0 g, 29.2 mmol), compound (K-1) (3.2 g, 32.1 mmol), and dichloromethane (170 g) were added to a 300 mL three-neck flask, and the mixture was stirred at room temperature to dissolve. Next, diisopropylcarbodiimide (4.1 g, 32.1 mmol) and dimethylaminopyridine (0.045 g, 0.4 mmol) were added, and the mixture was reacted at room temperature for 5 hours. The reaction solution was filtered, and the filtrate was concentrated using a rotary evaporator. The concentrate was dissolved in acetonitrile (30 g), and then dropped into MTBE (180 g), and the precipitated solid was filtered. The filtered product was again dissolved in acetonitrile (30 g), and then dropped into MTBE (180 g), and the precipitated solid was filtered. This operation was repeated twice, and the filtered product was dried under reduced pressure to obtain compound (D0pre-02).

[0494] [ka]

[0495] (Production Example 2-6) Compound (D0pre-03) was obtained in the same manner as in the production example of compound (D0pre-02), except that compound (K-1) (3.2 g, 32.1 mmol) was changed to compound (K-2) (5.6 g, 32.1 mmol).

[0496] [ka]

[0497] (Production Example 2-7) Compound (D0pre-04) was obtained in the same manner as in the production example of compound (D0pre-02), except that compound (K-1) (3.2 g, 32.1 mmol) was changed to compound (K-3) (2.4 g, 32.1 mmol).

[0498] [ka]

[0499] (Production Example 2-8) Compound (D0pre-05pre) was obtained in the same manner as in the production example of compound (D0pre-02), except that compound (K-1) (3.2 g, 32.1 mmol) was changed to ethylene glycol (2.0 g, 32.1 mmol).

[0500] [ka]

[0501] Next, compound (D0pre-05pre) (9.0 g, 21.4 mmol), oxalic acid (2.1 g, 23.5 mmol), and dichloromethane (95 g) were added to a 300 mL three-neck flask, and the mixture was stirred at room temperature to dissolve. Next, diisopropylcarbodiimide (3.0 g, 23.5 mmol) and dimethylaminopyridine (0.033 g, 0.3 mmol) were added, and the mixture was reacted at room temperature for 5 hours. The reaction solution was filtered, and the filtrate was concentrated using a rotary evaporator. The concentrate was dissolved in acetonitrile (15 g), and then dropped into MTBE (80 g), and the precipitated solid was filtered. The filtered product was again dissolved in acetonitrile (15 g), and then dropped into MTBE (80 g), and the precipitated solid was filtered. This operation was repeated twice, and the filtered product was dried under reduced pressure to obtain compound (D0pre-05).

[0502] [ka]

[0503] <Production of compound (D0)> (Production Example 3-1) Compound (D0pre-01) (3.0 g, 8.0 mmol) and compound (S-1-1) (2.86 g, 8.4 mmol) were dissolved in dichloromethane (50 g), and 5% tetramethylammonium hydroxide (TMAH) aqueous solution (14.5 g) was added and reacted at room temperature for 30 minutes. After the reaction was completed, the aqueous phase was removed and the organic phase was washed five times with ultrapure water (15.0 g). The organic phase was concentrated to dryness using a rotary evaporator to obtain compound (D0-01).

[0504] [ka]

[0505] (Manufacturing Examples 3-2 to 3-11) Compounds (D0-02) to (D0-11) shown below were obtained in the same manner as in the above "Production Example of Compound (D0-01)", except that the combination of compound (D0pre-01) and salt-exchange compound (S-1-1) in the above "Production Example of Compound (D0-01)" was changed to the above-mentioned compounds (D0pre-01) to (D0pre-08) and the following salt-exchange compounds (S-1-1) to (S-1-4), respectively. The structures of compounds (D0-01) to (D0-11) are shown below.

[0506] [ka]

[0507] [ka]

[0508] [ka]

[0509] The structures of the above-mentioned compounds (D0-01) to (D0-11) are shown below. 1 The identification was based on the results of H-NMR analysis.

[0510] Compound (D0-01): Combination of compound (D0pre-01) and salt exchange compound (S-1-1) 1 H-NMR(DMSO,400MHz):δ(ppm)=7.74-7.90 (m, ArH, 15H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85(m, CH, 2H), 3.15-3.40 (m, -OCO- CH-CH -COO-, 2H), 1.50-2.05 (m, cyclopenthyl, 8H), 1.40 (s, CH3, 3H)

[0511] Compound (D0-02): Combination of compound (D0pre-02) and compound for exchange (S-1-1) 1 H-NMR (DMSO, 400MHz): δ (ppm) = 7.74-7.90 (m, ArH, 15H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85 (m, CH, 2H), 3.15-3.40 (m, -OCO-CH-CH-COO-, 2H), 2.15 (s, -COO- CH 2-, 2H), 1.50-2.05 (m, cyclopenthyl, 8H), 1.40 (s, CH3, 3H)

[0512] Compound (D0-03): Combination of compound (D0pre-03) and compound for exchange (S-1-1) 1 H-NMR (DMSO, 400MHz): δ (ppm) = 7.74-7.90 (m, ArH, 15H), 7.01-7.47 (m, ArH, 8H), 6.73 (s, ArH, 2H), 4.70-4.85 (m, CH, 2H), 3.15-3.40 (m, -OCO-CH-CH-COO-, 2H), 1.50-2.05 (m, cyclopenthyl, 8H), 1.40 (s, CH3, 3H)

[0513] Compound (D0-04): Combination of compound (D0pre-04) and compound for exchange (S-1-1) 1 H-NMR (DMSO, 400MHz): δ (ppm) = 7.74-7.90 (m, ArH, 15H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85 (m, CH, 2H), 4.49 (s, -COO CH 2-, 2H), 3.15-3.40 (m, -OCO- CH-CH- COO-, 2H), 1.50-2.05 (m, cyclopenthyl, 8H), 1.40 (s, CH3, 3H)

[0514] Compound (D0-05): Combination of compound (D0pre-05) and salt exchange compound (S-1-1) 1 H-NMR(DMSO,400MHz):δ(ppm)=7.74-7.90 (m, ArH, 15H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85(m, CH, 2H), 3.79-3.95 (m, -COO- CH 2 CH 2-COO-, 4H), 3.15-3.40 (m, -OCO- CH-CH- COO-, 2H), 1.50-2.05 (m, cyclopenthyl, 8H), 1.40 (s, CH3, 3H)

[0515] Compound (D0-06): Combination of compound (D0pre-06) and salt exchange compound (S-1-1) 1 H-NMR(DMSO,400MHz):δ(ppm)=7.74-7.90 (m, ArH, 15H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85(m, CH, 2H), 3.15-3.40 (m, -OCO- CH-CH- COO-, 2H), 1.40 (s, CH3, 9H)

[0516] Compound (D0-07): Combination of compound (D0pre-07) and salt exchange compound (S-1-1) 1 H-NMR(DMSO,400MHz):δ(ppm)=7.74-7.90 (m, ArH, 15H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85(m, CH, 2H), 3.15-3.40 (m, -OCO- CH-CH- COO-, 2H), 1.50-2.00 (m, Methyl Adamanthyl, 17H)

[0517] Compound (D0-08): Combination of compound (D0pre-08) and salt exchange compound (S-1-1) 1H-NMR (DMSO, 400MHz): δ (ppm) = 7.74-7.90 (m, ArH, 15H), 7.19 (s, ArH, 4H), 4.70-4.85 (m, CH, 2H), 3.15-3.40 (m, -OCO- CH-CH -COO-, 2H), 2.27 (s, CH3, 12H), 1.50-2.05 (m, cyclopenthyl, 8H), 1.40 (s, CH3, 3H)

[0518] Compound (D0-09): Combination of compound (D0pre-05) and compound for exchange (S-1-2) 1 H-NMR (DMSO, 400MHz): δ (ppm) = 7.70-8.22 (m, ArH, 14H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85 (m, CH, 2H), 3.79-3.95 (m, -COO- CH 2 CH 2-COO-, 4H), 3.15-3.45 (m, -OCO- CH-CH- COO- + SO2 CH , 3H), 1.09-2.05 (m, methyl cyclopenthyl + cyclohexyl, 21H)

[0519] Compound (D0-10): Combination of compound (D0pre-04) and compound for exchange (S-1-4) 1 H-NMR (DMSO, 400MHz): δ (ppm) = 7.77-7.98 (m, ArH, 11H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85 (m, CH, 2H), 4.49 (s, -COO CH 2-, 2H), 3.15-3.40 (m, -OCO- CH-CH- COO-, 2H), 1.50-2.05 (m, cyclopenthyl, 8H), 1.40 (s, CH3, 3H)

[0520] Compound (D0-11): Combination of compound (D0pre-01) and compound for exchange (S-1-3) 1 H-NMR(DMSO,400MHz):δ(ppm)=8.50(d, ArH, 2H), 8.37(d, ArH, 2H), 7.93(t, ArH, 2H), 7.55-7.75(m, ArH, 7H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85(m, CH, 2H), 3.15-3.40 (m, -OCO- CH-CH -COO-, 2H), 1.50-2.05 (m, cyclopenthyl, 8H), 1.40 (s, CH3, 3H)

[0521] <Preparation of resist composition> (Examples 1 to 13, Comparative Examples 1 to 4) The components shown in Tables 1 and 2 were mixed and dissolved to prepare resist compositions of each example.

[0522] [Table 1]

[0523] [Table 2]

[0524] In Tables 1 and 2, the abbreviations have the following meanings: The numbers in brackets [ ] are the amounts blended (parts by mass).

[0525] (A)-1: A polymer compound represented by the following chemical formula (A1)-1. The weight average molecular weight (Mw) of this polymer compound (A1)-1, calculated in terms of standard polystyrene, determined by GPC measurement, is 7100, and the molecular weight dispersity (Mw / Mn) is 1.69. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0526] (A)-2: A polymer compound represented by the following chemical formula (A1)-2. The weight average molecular weight (Mw) of this polymer compound (A1)-2, calculated in terms of standard polystyrene, determined by GPC measurement, is 7000, and the molecular weight dispersity (Mw / Mn) is 1.72. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0527] [ka]

[0528] (B)-1: An acid generator comprising the following compound (B1-1): (B)-2: An acid generator comprising the following compound (B1-2):

[0529] [ka]

[0530] (D0)-1 to (D0)-11: Acid diffusion controllers consisting of the above-mentioned compounds (D0-01) to (D0-11), respectively. (D1)-1 to (D1)-4: Acid diffusion controllers consisting of the following compounds (D1-1) to (D1-4), respectively. (S)-1: a mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0531] [ka]

[0532] <Formation of Resist Pattern> Each resist composition of the example was applied using a spinner onto an 8-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 electron beam lithography system JEOL-JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100 kV to form a contact hole pattern (hereinafter referred to as a "CH pattern") in which holes with a diameter of 32 nm were arranged at equal intervals (pitch of 64 nm).Then, a post-exposure bake (PEB) treatment was performed at 110°C for 60 seconds. Next, alkaline development was carried out at 23° C. for 60 seconds using a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, the substrate was rinsed with pure water for 15 seconds. As a result, a CH pattern was formed in which holes with a diameter of 32 nm were arranged at equal intervals (pitch 64 nm).

[0533] [Evaluation of Pattern Dimension Uniformity (CDU)] The CH pattern formed by the above <Formation of Resist Pattern> was observed from above the CH pattern using a length measuring SEM (scanning electron microscope, accelerating voltage 500V, product name: CG5000, manufactured by Hitachi High-Technologies Corporation), and the hole diameter (nm) of each hole was measured. Then, the triple value (3σ) of the standard deviation (σ) calculated from the measurement results was calculated. The results are shown in Table 3 as "CDU (nm)". The smaller the value of 3σ thus determined, the higher the uniformity of the dimensions (CD) of the multiple holes formed in the resist film.

[0534] [Evaluation of limiting resolution] The limiting resolution at the optimum exposure dose (Eop) at which the above CH pattern is formed, specifically, the hole diameter (nm) of the resolved pattern when the exposure dose is gradually decreased from the optimum exposure dose (Eop) to form the CH pattern, was determined using a scanning electron microscope S-9380 (Hitachi High-Tech Corporation). The results are shown in Table 3 as "limiting resolution (nm)".

[0535] [Table 3]

[0536] As shown in Table 3, it was confirmed that the resist compositions of the examples were capable of forming resist patterns that were superior in both CDU and limiting resolution compared to the resist compositions of the comparative examples.

[0537] By comparing Examples 1 to 8, the effects of differences in the anion moiety of the component (D0) were confirmed. As a result, the resist compositions containing the component (D0) of Examples 2, 4, and 5 were particularly superior in CDU and limiting resolution.

[0538] In comparing the components (D0) contained in the resist compositions of Examples 1 and 6, which differ only in the acid-dissociable group possessed by the component (D0), it is presumed that the acid-dissociable group, which is a monocyclic alicyclic group, possessed by the anion moiety of the component (D0) of Example 1 has a higher dissociation ability than the chain acid-dissociable group possessed by the anion moiety of the component (D0) of Example 6, and therefore the component (D0) of Example 1 was able to further improve the affinity with the developer.

[0539] In comparing the components (D0) contained in the resist compositions of Examples 1 and 7, which differ only in the acid-dissociable group possessed by the component (D0), the acid-dissociable group, which is a monocyclic alicyclic group, possessed by the anion moiety of the component (D0) of Example 1 is suitably less hydrophobic than the acid-dissociable group which is a polycyclic alicyclic group possessed by the anion moiety of the component (D0) of Example 7. It is therefore presumed that the component (D0) of Example 1 is able to improve affinity with the developer while maintaining uniformity within the resist film.

[0540] In comparing the components (D0) contained in the resist compositions of Examples 1 and 8, which differ only in the acid-dissociable group of the component (D0), the bicyclooctane skeleton of the anion moiety of the component (D0) of Example 1 is suitably less hydrophobic than the bicyclooctane skeleton having four methyl groups in the anion moiety of the component (D0) of Example 8. It is therefore presumed that the component (D0) of Example 1 is able to maintain uniformity within the resist film while improving affinity with the developer.

Claims

1. A resist composition which generates an acid upon exposure and changes its solubility in a developer by the action of the acid, a base component (A) 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 an acid diffusion controller component (D) that controls the diffusion of the acid generated from the acid generator component (B) upon exposure to light, The resist composition, wherein the acid diffusion controller component (D) contains a compound (D0) represented by the following general formula (d0): 【Chemistry 1】 [In the formula, Rd ０ is a polycyclic aromatic cyclic group in which a plurality of aromatic hydrocarbon rings are condensed together, or an aromatic hydrocarbon ring-aliphatic hydrocarbon ring fused cyclic group in which an aromatic hydrocarbon ring is condensed with an aliphatic hydrocarbon ring. The polycyclic aromatic cyclic group and the aromatic hydrocarbon ring-aliphatic hydrocarbon ring fused cyclic group have an acid-decomposable group represented by the following general formula (pg-1) as a substituent, and may have an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, or a carbonyl group. ０ is a single bond. ｍ＋ represents an m-valent organic cation, where m is an integer of 1 or more. 【Chemistry 2】 [In formula (pg-1), Rpg is an acid dissociable group represented by the following general formula (pg-r-1), an acid dissociable group represented by the following general formula (pg-r-2), an acid dissociable group represented by the following general formula (pg-r-3), or an acid dissociable group represented by the following general formula (pg-r-4). * represents a bond.] 【Chemistry 3】 In formula (pg-r-1), Rd 1 to Rd 3 each independently represent a hydrocarbon group, and Rd 1 and Rd 2 may be bonded to each other to form a ring. In formula (pg-r-2), Rd 001 represents a linear or branched aliphatic hydrocarbon group. Yd 002 represents a single bond or a divalent linking group. Rd 002 represents a hydrogen atom or a substituent. Ar represents a benzene ring or a naphthalene ring. Rm 01 represents a substituent. n01 represents an integer of 1 to 4. In formula (pg-r-3), Xd is a secondary carbon atom. X is an alicyclic hydrocarbon ring which may have a substituent. Ar is a benzene ring or a naphthalene ring. Rm 02 is a substituent. n02 is an integer of 1 to 4. In formula (pg-r-4), Rd' 1 and Rd' 2 are each a hydrogen atom or an alkyl group. Rd' 3 is a hydrocarbon group, and Rd' 3 may be bonded to either Rd' 1 or Rd' 2 to form a ring. * indicates a bond to the oxygen atom (—O—) in general formula (pg-1).]

2. 2. The resist composition according to claim 1, wherein the acid diffusion controller component (D) comprises a compound represented by the following general formula (d0-1): 【Chemistry 4】 [In the formula, Rx １ ~Rx ４ R each independently represents an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, a hydrocarbon group which may have a carbonyl group, or a hydrogen atom, or two or more of them may be bonded to each other to form a ring structure. １ ~Ry ２ each independently represents an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, a hydrocarbon group which may have a carbonyl group, or a hydrogen atom, or may be bonded to each other to form a ring structure. 【Chemistry 5】 is a double bond or a single bond. １ ~Rz ４ Rx each independently represents, if permitted by atomic valence, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, a hydrocarbon group which may have a carbonyl group, or a hydrogen atom, or two or more of them may be bonded to each other to form a ring structure. １ ~Rx ４ Two or more of Ry １ ~Ry ２ , or Rz １ ~Rz ４ At least one of two or more of Rx is bonded to each other to form an aromatic ring. １ ~Rx ４ , Ry １ ~Ry ２ and Rz １ ~Rz ４ At least one of Rx has an anion group represented by the following general formula (d0-r-an1), and the entire anion portion is an n-valent anion. １ ~Rx ４ , Ry １ ~Ry ２ and Rz １ ~Rz ４ At least one of the groups has an acid-decomposable group represented by the general formula (pg-1). n is an integer of 1 or more. m is an integer of 1 or more, M ｍ＋ represents an m-valent organic cation. 【Chemistry 6】 [Wherein, Yd ０ is a single bond. * indicates a bond.

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

4. An acid diffusion controller for a resist composition, comprising a compound represented by the following general formula (d0): 【Chemistry 7】 [In the formula, Rd ０ is a polycyclic aromatic cyclic group in which a plurality of aromatic hydrocarbon rings are condensed together, or an aromatic hydrocarbon ring-aliphatic hydrocarbon ring fused cyclic group in which an aromatic hydrocarbon ring is condensed with an aliphatic hydrocarbon ring. The polycyclic aromatic cyclic group and the aromatic hydrocarbon ring-aliphatic hydrocarbon ring fused cyclic group have an acid-decomposable group represented by the following general formula (pg-1) as a substituent, and may have an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, or a carbonyl group. ０ is a single bond. ｍ＋ represents an m-valent organic cation, where m is an integer of 1 or more. 【Chemistry 8】 [In formula (pg-1), Rpg is an acid dissociable group represented by the following general formula (pg-r-1), an acid dissociable group represented by the following general formula (pg-r-2), an acid dissociable group represented by the following general formula (pg-r-3), or an acid dissociable group represented by the following general formula (pg-r-4). * represents a bond.] 【Chemistry 9】 In formula (pg-r-1), Rd 1 to Rd 3 each independently represent a hydrocarbon group, and Rd 1 and Rd 2 may be bonded to each other to form a ring. In formula (pg-r-2), Rd 001 represents a linear or branched aliphatic hydrocarbon group. Yd 002 represents a single bond or a divalent linking group. Rd 002 represents a hydrogen atom or a substituent. Ar represents a benzene ring or a naphthalene ring. Rm 01 represents a substituent. n01 represents an integer of 1 to 4. In formula (pg-r-3), Xd is a secondary carbon atom. X is an alicyclic hydrocarbon ring which may have a substituent. Ar is a benzene ring or a naphthalene ring. Rm 02 is a substituent. n02 is an integer of 1 to 4. In formula (pg-r-4), Rd' 1 and Rd' 2 are each a hydrogen atom or an alkyl group. Rd' 3 is a hydrocarbon group, and Rd' 3 may be bonded to either Rd' 1 or Rd' 2 to form a ring. * indicates a bond to the oxygen atom (—O—) in general formula (pg-1).]

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