Resist composition and resist pattern forming method

Abstract

The present invention provides: a resist composition from which a resist pattern having favorable roughness-reducing properties can be formed; and a resist pattern forming method using said resist composition. The present invention pertains to a resist composition which generates an acid when exposed to light and of which the solubility in a developing solution changes due to the action of the acid, the resist composition comprising a base material component (A) of which the solubility in a developing solution changes due to the action of an acid, and an acid diffusion control component (D), wherein: the base material component (A) contains a polymer compound (A1) having a weight-average molecular weight of at least 30,000; the polymer compound (A1) has a constitutional unit (a1) represented by general formula (a-1) and a constitutional unit (a2) represented by general formula (a-2), which are disclosed in the specification; and the acid diffusion control component (D) contains at least one compound (D1) selected from the group consisting of compounds represented by general formula (d1-1) disclosed in the specification and compounds represented by general formula (d1-2) disclosed in the specification.

Description

Resist composition and method for forming a resist pattern

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

[0002] In lithography, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed to light, and a development process is performed to form a resist pattern of a predetermined shape in the resist film. A resist material that changes the exposed portion of the resist film so that it dissolves in a developer is called a positive-type resist, and a resist material that changes the exposed portion so that it does not dissolve in a developer is called a negative-type resist.

[0003] 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 for miniaturization is to shorten the wavelength (increase the energy) of the exposure light source. Specifically, while ultraviolet rays such as g-line and i-line have traditionally been used, mass production of semiconductor devices using KrF excimer lasers and ArF excimer lasers has now begun. Furthermore, studies are also being conducted on EUV (extreme ultraviolet), EB (electron beam), X-rays, and other light sources with shorter wavelengths (higher energies) than excimer lasers.

[0004] Resist materials are required to have lithography properties such as sensitivity to these exposure light sources, resolution capable of reproducing fine-dimensional patterns, etc. To satisfy these requirements, a chemically amplified resist composition containing an acid generator component that generates acid upon exposure and a base component whose solubility in a developer changes due to the action of acid has been used.

[0005] The base resin used as the base component in a chemically amplified resist composition generally contains multiple structural units in order to improve lithography properties, etc. For example, Patent Document 1 discusses a resist composition and a method for forming a resist pattern that can achieve high sensitivity, have excellent lithography properties, and form a resist pattern with a good shape. Patent Document 1 also describes a resist composition that employs a polymer compound containing multiple structural units with a specific structure and improves dissociation performance against acid.

[0006] Japanese Patent Application Publication No. 2020-098250

[0007] As lithography technology continues to advance and resist patterns become increasingly finer, resist compositions are required to be able to form finer patterns with good shapes. However, conventional techniques have not always been able to sufficiently reduce roughness in resist pattern formation, and a higher level of roughness reduction is required.

[0008] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a resist composition capable of forming a resist pattern that exhibits excellent roughness reduction, a method of forming a resist pattern that uses the resist composition, and a salt that is useful for the resist composition.

[0009] As a result of intensive research conducted by the present inventors in order to solve the above-mentioned problems, they discovered that the following configurations make it possible to obtain a resist composition that is capable of forming a resist pattern that achieves reduced roughness, and a method of forming a resist pattern that uses such a resist composition, and thus completed the present invention.

[0010] That is, the present invention is as follows.

[0011] A resist composition according to an embodiment of the present invention is a resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, and contains a base component (A) whose solubility in a developer changes due to the action of the acid, and an acid diffusion control component (D), wherein the base component (A) contains a polymeric compound (A1) having a weight-average molecular weight of 30,000 or more, and the polymeric compound (A1) has a structural unit (a1) represented by the following general formula (a-1) and a structural unit (a2) represented by the following general formula (a-2), and the acid diffusion control component (D) contains one or more compounds (D1) selected from the group consisting of compounds represented by the following general formula (d1-1) and compounds represented by the following general formula (d1-2):

[0012]

[0013] [In general formula (a-1), R ０１ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ is a divalent hydrocarbon group which may have an ether bond. ａ０１ is an integer from 0 to 2. ０１ is an acid-dissociable group.

[0014]

[0015] [In general formula (a-2), R ０２ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０２ is a divalent hydrocarbon group which may have an ether bond. ａ０２ is an integer from 0 to 2. ０２ is a lactone-containing cyclic group, —SO ２ -containing cyclic group, or carbonate-containing cyclic group.

[0016]

[0017] [In general formula (d1-1) and general formula (d1-2), Rd １ and Rd ２are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula (I), no fluorine atom is bonded to the carbon atom adjacent to the S atom. m is an integer of 1 or more, and M ｍ＋ are each independently an m-valent organic cation.

[0018] A method for forming a resist pattern according to another embodiment of the present invention is a method for forming a resist pattern, including the steps of forming a resist film on a support using a resist composition according to an embodiment of the present invention, exposing the resist film to light, and developing the resist film to form a resist pattern.

[0019] The present invention is capable of providing a resist composition capable of forming a resist pattern with excellent roughness reduction properties, and a method of forming a resist pattern using the resist composition.

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes in detail the preferred embodiments of the present invention, but the present invention is not limited to the following preferred embodiments.

[0021] In this specification and claims, "aliphatic" is a relative concept to aromatic and is defined as meaning a group, compound, etc. that does not have aromaticity. Unless otherwise specified, "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, "alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups. A "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group have been substituted with halogen atoms, and examples of such halogen atoms include fluorine, chlorine, bromine, and iodine atoms. A "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which some or all of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms. A "structural unit" refers to a monomer unit that constitutes a polymer compound (resin, polymer, copolymer). The phrase "optionally has a substituent" refers to the case in which a hydrogen atom (-H) is replaced with a monovalent group, and the case in which a methylene group (-CH ２ The term "exposure" encompasses both cases where the radical (-) is substituted with a divalent group.

[0022] An "acid-decomposable group" is a group having acid decomposability in which at least a part of the bond in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases by the action of an acid include groups that decompose by the action of an acid to generate a polar group. Examples of polar groups include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO ３ More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, groups in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0023] The term "acid-dissociable group" refers to either (i) a group having acid dissociability in which the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group in which a part of the bond is cleaved by the action of an acid, followed by a decarboxylation reaction, in which the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved. The acid-dissociable group constituting the acid-decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid-dissociable group. Thus, when the acid-dissociable group is dissociated by the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, thereby increasing the polarity. As a result, the polarity of the entire component (A1) described below 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.

[0024] The "base component" refers to an organic compound having film-forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved, and in addition, it becomes easier to form nano-level resist patterns. Organic compounds used as base components are broadly classified 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," or "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 in terms of polystyrene measured by GPC (gel permeation chromatography).

[0025] The term "structural unit derived from an acrylic acid ester" refers to a structural unit formed by cleavage of the ethylenic double bond of an acrylic acid ester. ２═CH—COOH) with an organic group substituted for the hydrogen atom at the carboxyl end of the acrylate ester. The hydrogen atom bonded to the α-position carbon atom in the acrylate ester may be substituted with a substituent. The substituent (R α０ ) is an atom or group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms. α０ ) is substituted with a substituent containing an ester bond, or α０ This also includes α-hydroxyacrylic esters in which the α-position carbon atom of an acrylic ester is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group. Unless otherwise specified, the α-position carbon atom of an acrylic ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom is substituted with a substituent may be referred to as an α-substituted acrylic ester. Furthermore, acrylic esters and α-substituted acrylic esters may be collectively referred to as "(α-substituted) acrylic esters."

[0026] The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, and specific examples thereof include alkyl groups having 1 to 5 carbon atoms (methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups). Specific examples of halogenated alkyl groups as the substituent at the α-position include groups in which some or all of the hydrogen atoms of the above-mentioned "alkyl group as the substituent at the α-position" have been substituted with halogen atoms. Examples of such halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine atoms being particularly preferred. Specific examples of hydroxyalkyl groups as the substituent at the α-position include groups in which some or all of the hydrogen atoms of the above-mentioned "alkyl group as the substituent at the α-position" have been substituted with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

[0027] In this disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. Furthermore, in this disclosure, when multiple substances corresponding to each component are present in the composition, the amount of each component refers to the total amount of the multiple corresponding substances present in the composition, unless otherwise specified. Furthermore, chemical structural formulas in this disclosure may be described as simplified structural formulas in which hydrogen atoms are omitted. In this specification and claims, depending on the structure represented by a chemical formula, asymmetric carbon atoms may be present, and enantiomers or diastereoisomers may exist. In such cases, a single chemical formula represents these isomers. These isomers may be used alone or as a mixture. In this disclosure, "mass %" and "wt %" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0028] [Resist Composition] A resist composition according to an embodiment of the present invention is a resist composition that generates acid upon exposure, and whose solubility in a developer changes due to the action of the acid. The resist composition includes a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of the acid, and an acid diffusion control component (D) (hereinafter also referred to as "component (D)"). The base component (A) includes a polymeric compound (A1) having a weight-average molecular weight of 30,000 or more. The polymeric compound (A1) (hereinafter also referred to as "component (A1)") has a structural unit (a1) represented by the following general formula (a-1) and a structural unit (a2) represented by the following general formula (a-2). The acid diffusion control component (D) includes one or more compounds (D1) selected from the group consisting of compounds represented by the following general formula (d1-1) and compounds represented by the following general formula (d1-2).

[0029]

[0030] [In general formula (a-1), R ０１ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ is a divalent hydrocarbon group which may have an ether bond. ａ０１is an integer from 0 to 2. ０１ is an acid-dissociable group.

[0031]

[0032] [In general formula (a-2), R ０２ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０２ is a divalent hydrocarbon group which may have an ether bond. ａ０２ is an integer from 0 to 2. ０２ is a lactone-containing cyclic group, —SO ２ -containing cyclic group, or carbonate-containing cyclic group.

[0033]

[0034] [In general formula (d1-1) and general formula (d1-2), Rd １ and Rd ２ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula (I), no fluorine atom is bonded to the carbon atom adjacent to the S atom. m is an integer of 1 or more, and M ｍ＋ are each independently an m-valent organic cation.

[0035]

[0023] When a resist film is formed using the resist composition according to an embodiment of the present invention and the resist film is subjected to selective exposure, an acid is generated in the exposed areas of the resist film, and the solubility of the component (A) in a developer changes due to the action of the acid, whereas the solubility of the component (A) in a developer does not change in the unexposed areas of the resist film, resulting in a difference in solubility in a developer between the exposed and unexposed areas of the resist film. Therefore, when the resist film is developed, if the resist composition is positive, the exposed areas of the resist film are dissolved and removed, forming a positive resist pattern, and if the resist composition is negative, the unexposed areas of the resist film are dissolved and removed, forming a negative resist pattern.

[0036] In this specification, a resist composition that forms a positive resist pattern by dissolving and removing exposed portions of a resist film is referred to as a positive resist composition, and a resist composition that forms a negative resist pattern by dissolving and removing unexposed portions of a resist film is referred to as a negative resist composition. A resist composition according to an embodiment of the present invention may be a positive resist composition or a negative resist composition. Furthermore, a resist composition according to an embodiment of the present invention may be used for an alkaline development process in which an alkaline developer is used for the development treatment during resist pattern formation, or may be used for a solvent development process in which a developer containing an organic solvent (organic developer) is used for the development treatment.

[0037] The resist composition according to the embodiment of the present invention has an acid generating ability that generates an acid upon exposure. The component (A) may generate an acid upon exposure, or an additive component formulated separately from the component (A) may generate an acid upon exposure. Specifically, the resist composition according to the embodiment of the present invention may further contain (1) an acid generator component (B) (hereinafter referred to as "component (B)") that generates an acid upon exposure; (2) the component (A) may be a component that generates an acid upon exposure; or (3) the component (A) may be a component that generates an acid upon exposure and further contain component (B). That is, in the case of the above (2) and (3), the component (A) is a "base component that generates an acid upon exposure and whose solubility in a developer is changed by the action of the acid." When the component (A) is a base component that generates an acid upon exposure and whose solubility in a developer is changed by the action of the acid, it is preferable that the component (A1), described below, is a polymeric compound that generates an acid upon exposure and whose solubility in a developer is changed by the action of the acid. As such a polymer compound, a resin having a structural unit that generates an acid upon exposure can be used. Known structural units that generate an acid upon exposure can be used. Among these, the resist composition according to the embodiment of the present invention is preferably the above-mentioned case (1).

[0038] In the resist composition according to an embodiment of the present invention, the polymer compound (A1) contained in the base component (A) has a weight-average molecular weight of 30,000 or more, includes a structural unit (a1) represented by general formula (a-1) and a structural unit (a2) represented by general formula (a-2), and contains an acid diffusion control component (D) having a specific structure. Therefore, when used to form a resist film, the resist composition is effective in improving the reduction of roughness of the resist film. Furthermore, in an alkaline development process, the solubility of the resist film in an alkaline developer is enhanced during development. The synergistic effect of the base component (A) having a weight-average molecular weight of 30,000 or more and a specific structure and the acid diffusion control component (D) having a specific structure makes it possible to simultaneously suppress variations in the deprotection reaction and improve acid diffusion control ability, thereby further increasing the reaction contrast at the interface between exposed and unexposed areas. Therefore, it is presumed that the resist composition according to an embodiment of the present invention can reduce roughness and form a resist pattern with a good shape.

[0039] <Component (A)> In the resist composition according to an embodiment of the present invention, the component (A) is a base component whose solubility in a developer changes under the action of an acid, and includes the above-mentioned component (A1). The component (A) may be one whose solubility in a developer increases under the action of an acid, or one whose solubility in a developer decreases under the action of an acid. By using the component (A), the polarity of the base component changes before and after exposure, and therefore good development contrast can be obtained not only in an alkaline development process but also in a solvent development process.

[0040] When an alkaline development process is applied, the base component containing the component (A1) is poorly soluble in an alkaline developer before exposure, and when, for example, an acid is generated upon exposure, the polarity increases due to the action of the acid, thereby increasing the solubility in an alkaline developer. Therefore, in forming a resist pattern, when a resist film obtained by applying the resist composition to a support is selectively exposed, the exposed areas of the resist film change from being poorly soluble in an alkaline developer to being soluble, while the unexposed areas of the resist film remain poorly soluble in alkali, and therefore a positive resist pattern is formed by alkaline development.

[0041] On the other hand, when a solvent development process is applied, the base component containing the component (A1) is highly soluble in organic developers before exposure, but when an acid is generated upon exposure, for example, the polarity increases due to the action of the acid, and the solubility in organic developers decreases. Therefore, in forming a resist pattern, when a resist film obtained by applying the resist composition to a support is selectively exposed, the exposed areas of the resist film change from soluble to poorly soluble in organic developers, while the unexposed areas of the resist film remain soluble. Therefore, by developing with an organic developer, a contrast can be created between the exposed and unexposed areas, and a negative resist pattern can be formed.

[0042] In the resist composition according to an embodiment of the present invention, the component (A) may be used alone or in combination of two or more different compounds. As the component (A), at least the component (A1) is used, and other polymeric compounds and / or low molecular weight compounds may also be used in combination with the component (A1).

[0043] <Structural Unit (a1)> The structural unit (a1) is represented by the following general formula (a-1).

[0044]

[0045] [In general formula (a-1), R ０１ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ is a divalent hydrocarbon group which may have an ether bond. ａ０１ is an integer from 0 to 2. ０１ is an acid-dissociable group.

[0046] In general formula (a-1), R ０１ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１The alkyl group having 1 to 5 carbon atoms represented by is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. A fluorine atom is particularly preferred as the halogen atom. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the perspective of industrial ease of availability, a hydrogen atom or a methyl group is most preferred.

[0047] In the formula (a-1), Va ０１ represents a divalent hydrocarbon group which may have an ether bond. ０１ The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0048] Va ０１ The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0049] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５The branched chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched chain aliphatic hydrocarbon group, a branched chain alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0050] Examples of the aliphatic hydrocarbon group containing a ring in its structure include alicyclic hydrocarbon groups (groups in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. A preferred monocyclic alicyclic hydrocarbon group is a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0051] Va ０１The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (an arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (an aryl group) has been substituted with an alkylene group (for example, a group in which one further hydrogen atom has been removed from the aryl group of an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 or 2, and particularly preferably 1.

[0052] n ａ０１ is an integer of 0 to 2, with 0 being preferred.

[0053] Ra ０１ In the structural unit (a1), Ra is an acid-dissociable group. ０１ Examples of the acid-dissociable group represented by the formula (I) include those that have been proposed as acid-dissociable groups for base resins for chemically amplified resists. Specific examples of acid-dissociable groups that have been proposed as acid-dissociable groups for base resins for chemically amplified resist compositions include "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "tertiary alkyloxycarbonyl acid-dissociable groups."

[0054] Acetal-Type Acid-Dissociable Group: Among the polar groups, examples of the acid-dissociable group that protects a carboxy group or a hydroxyl group include acid-dissociable groups represented by the following formula (a1-r-1) (hereinafter, sometimes referred to as "acetal-type acid-dissociable group").

[0055]

[0056] [In formula (a1-r-1), 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.]

[0057] In formula (a1-r-1), Ra' １ and Ra' ２ Among Ra', at least one is preferably a hydrogen atom, and more preferably both are hydrogen atoms. １ or Ra' ２ When is an alkyl group, examples of the alkyl group include the same alkyl groups as those exemplified as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester above, and alkyl groups having 1 to 5 carbon atoms are preferred. Specific examples include linear or branched alkyl groups. More specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. A methyl group or an ethyl group is more preferred, and a methyl group is particularly preferred.

[0058] In formula (a1-r-1), Ra' ３ The hydrocarbon group is preferably an aliphatic hydrocarbon group, more preferably an alicyclic hydrocarbon group. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group, and is preferably a monocyclic group.

[0059] The monocyclic alicyclic 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 polycyclic alicyclic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0060] Ra' ３ The alicyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R Ｐ１ , -R Ｐ２ -O-R Ｐ１ , -R Ｐ２ -CO-R Ｐ１ , -R Ｐ２ -CO-O-R 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 ０５ ") etc. Here, R Ｐ１ is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Ｐ２ is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Ｐ１ and R Ｐ２ Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group, and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents alone, or may have one or more of each of two or more of the above-mentioned substituents.

[0061] Examples of monovalent linear saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups. Examples of monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0062] Ra' ３ But Ra' １ , Ra' ２ When the cyclic group is bonded to any one of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0063] Tertiary alkyl ester-type acid-dissociable group: Among the polar groups, examples of the acid-dissociable group protecting the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), Ra' ４ ~Ra' ６ and each represent an alkyl group, the group may be referred to as a "tertiary alkyl ester-type acid-dissociable group" for convenience.

[0064]

[0065] [In formula (a1-r-2), Ra' ４ ~Ra' ６ are each a hydrocarbon group, and Ra' ４ ~Ra' ６ At least one of Ra' is an alicyclic hydrocarbon group, or ５ , Ra' ６ are bonded to each other to form an alicyclic hydrocarbon group.

[0066] Ra'４ ~Ra' ６ Examples of the hydrocarbon group of Ra' include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. ４ ~Ra' ６ At least one of Ra' is an alicyclic hydrocarbon group, or ５ , Ra' ６ are bonded to each other to form an alicyclic hydrocarbon group.

[0067] The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Of these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0068] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0069] Ra' ４ ~Ra' ６ When either of the above is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.

[0070] Ra' ４ ~Ra' ６When any of the above is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

[0071] Specific examples of the aromatic hydrocarbon group include groups in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl groups or heteroaryl groups); groups in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, and 2-naphthylethyl). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0072] The cyclic hydrocarbon group may have a substituent. Examples of the substituent include Ra' in the above formula (a1-r-1). ３ Examples of the substituents include the same as those that the alicyclic hydrocarbon group in the above may have.

[0073] Ra' ５ and Ra' ６and R a′ are bonded to each other to form a ring, examples of the acid-dissociable group preferably include groups represented by the following formula (a1-r2-1), groups represented by the following formula (a1-r2-2), and groups represented by the following formula (a1-r2-3). ４ ~Ra' ６ When the groups are not bonded to each other but are independent hydrocarbon groups, examples of the acid-dissociable group preferably include groups represented by the following formula (a1-r2-4):

[0074]

[0075] [In formula (a1-r2-1), Ra ０３１ represents an alkyl group having 1 to 10 carbon atoms. ０ represents a carbon atom. ０ is Yab ０ In formula (a1-r2-2), Ya represents a carbon atom. Xa represents a group that forms an alicyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra １０１ ~Ra １０３ are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. １０１ ~Ra １０３ Two or more of the above may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ In formula (a1-r2-4), Ra′ is an aromatic hydrocarbon group which may have a substituent. １２ and Ra' １３ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms of this chain saturated hydrocarbon group may be substituted. １４ is an alicyclic hydrocarbon group. * indicates a bond.

[0076] In the above formula (a1-r2-1), Ra０３１ In the formula, the alkyl group having 1 to 10 carbon atoms includes a linear or branched alkyl 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, an n-pentyl group, and the like, with a methyl group or an ethyl group being preferred. The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0077] Ra in the above formula (a1-r2-1) ０３１ Among the above, a linear alkyl group having 1 to 5 carbon atoms is preferred, and specifically, a methyl group or an ethyl group is preferred.

[0078] In formula (a1-r2-1), Xab ０ (Yab ０ The alicyclic group (which together with the alicyclic group forms an alicyclic hydrocarbon) is preferably a monocyclic alicyclic hydrocarbon group, and examples thereof include groups in which two or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, and even more preferably 3 to 6 carbon atoms. Specific examples of suitable monocycloalkanes include cyclopentane and cyclohexane.

[0079] In the formula (a1-r2-2), the alicyclic hydrocarbon group formed by Xa together with Ya is preferably a monocyclic alicyclic hydrocarbon group. ０ In formula (a1-r2-2), Ra １０１ ~Ra １０３ In the formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. １０１~Ra １０３ In the formula (R), 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. １０１ ~Ra １０３ Among the above, from the viewpoint of ease of synthesis of the monomer compound, is preferably a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferred, and a hydrogen atom is particularly preferred.

[0080] The above Ra １０１ ~Ra １０３ Examples of the substituents that the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the formula (I) include the above-mentioned Ra ０５ The same groups as those shown below can be mentioned.

[0081] Ra １０１ ~Ra １０３ Examples of the group containing a carbon-carbon double bond formed by two or more of the above being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidene-ethenyl group, a cyclohexylidene-ethenyl group, etc. Among these, from the viewpoint of ease of synthesis of the monomer compound, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0082] In the formula (a1-r2-3), the alicyclic hydrocarbon group formed by Xaa together with Yaa is preferably a monocyclic alicyclic hydrocarbon group, and Ra' in the above formula (a1-r-2) is preferably a monocyclic alicyclic hydrocarbon group. ４ In the formula (a1-r2-3), Ra １０４ Examples of the aromatic hydrocarbon group in the formula (I) include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. １０４is 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.

[0083] Ra in formula (a1-r2-3) １０４ Examples of the substituent that may be possessed by the group include a methyl group, an ethyl group, a propyl group, a hydroxy group, a carboxyl group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, etc.), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), an alkyloxycarbonyl group, and the like.

[0084] In formula (a1-r2-4), Ra' １２ and Ra' １３ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. １２ and Ra' １３ In the formula (I), the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned Ra １０１ ~Ra １０３ The monovalent saturated chain hydrocarbon group having 1 to 10 carbon atoms in the formula (1) may be substituted in part or in whole. １２ and Ra' １３ Among these, Ra' is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group, and most preferably a methyl group. １２ and Ra' １３ In the case where the chain saturated hydrocarbon group represented by the formula: ０５ The same groups as those shown below can be mentioned.

[0085] In formula (a1-r2-4), Ra' １４ is an alicyclic hydrocarbon group, and is preferably a monocyclic alicyclic hydrocarbon group which may have a substituent. １４Examples of the alicyclic hydrocarbon group in include groups in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, and even more preferably 3 to 6 carbon atoms. Specific examples of suitable monocycloalkanes include cyclopentane and cyclohexane.

[0086] Ra' １４ Examples of the substituent that may be possessed by Ra include １０４ Examples of the substituents include the same as those that may be possessed by the group.

[0087] Specific examples of the group represented by the formula (a1-r2-1) are listed below: In the following formula, * represents a bond.

[0088]

[0089]

[0090] Specific examples of the group represented by the formula (a1-r2-2) are listed below: In the following formula, * represents a bond.

[0091]

[0092]

[0093]

[0094] Specific examples of the group represented by the formula (a1-r2-3) are listed below: In the following formula, * represents a bond.

[0095]

[0096] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0097]

[0098] Tertiary alkyloxycarbonyl acid-dissociable group: Examples of the acid-dissociable group that protects the hydroxyl group of the polar group include an acid-dissociable group represented by the following formula (a-r-3) (hereinafter, for convenience, may be referred to as a "tertiary alkyloxycarbonyl acid-dissociable group").

[0099]

[0100] [In the formula, Ra' ７ ~Ra' ９ Each represents an alkyl group.

[0101] In formula (ar-3), Ra' ７ ~Ra' ９ are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably 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 or 4.

[0102] Of the groups represented by the general formulae (a1-r2-1) to (a1-r2-4), the acid-dissociable group is preferably the group represented by the general formula (a1-r2-1). That is, the base component (A) according to the embodiment of the present invention preferably contains a polymeric compound (A1) having a structural unit containing the acid-dissociable group represented by the formula (a1-r2-1).

[0103] In the structural unit (a1), general formula (a-1) is preferably represented by the following general formula (a1-2):

[0104]

[0105] (In general formula (a1-2), R ０１ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ is a divalent hydrocarbon group which may have an ether bond. ３ represents an integer of 0 to 2. ０３１ represents an alkyl group, and Yab ０ represents a carbon atom. ０ is Yab ０ represents a group which, together with the group, forms an alicyclic hydrocarbon group, and some or all of the hydrogen atoms of this alicyclic hydrocarbon group may be substituted.

[0106] In general formula (a1-2), R ０１ and Va ０１ are R in the general formula (a-1), respectively. ０１ and Va ０１ is the same as:

[0107] In general formula (a1-2), na ３ is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0108] In general formula (a1-2), Ra ０３１ is as mentioned above.

[0109] In general formula (a1-2), Ra ０３１ Among the above, is preferably a chain alkyl group, more preferably a monovalent chain alkyl group having 1 to 3 carbon atoms, and more specifically, a methyl group, an ethyl group, a propyl group, or an isopropyl group.

[0110] In general formula (a1-2), Yab ０ and Xab ０ are the Yab groups in the formula (a1-r2-1), respectively. ０ and Xab ０ is the same as:

[0111] Specific examples of the structural unit (a1) are listed below. α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122] ​

[0123] The structural unit (a1) that the component (A1) may have may be one type, or two or more types. Within the component (A1), the proportion of the structural unit (a1) relative to the total (100 mol%) of all structural units constituting the component (A1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%. By ensuring that the proportion of the structural unit (a1) is at or above the lower limit of the above-mentioned preferred range, lithography properties such as high sensitivity, resolution, and improved roughness are improved. Furthermore, by ensuring that the proportion is at or below the upper limit, a balance with other structural units can be achieved, resulting in various favorable lithography properties.

[0124] <Structural Unit (a2)> The structural unit (a2) is a structural unit represented by the following general formula (a-2).

[0125]

[0126] [In general formula (a-2), R ０２ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０２ is a divalent hydrocarbon group which may have an ether bond. ａ０２ is an integer from 0 to 2. ０２ is a lactone-containing cyclic group, —SO ２ -containing cyclic group, or carbonate-containing cyclic group.

[0127] In the formula (a-2), R ０２ is R in the formula (a-1). ０１ It is the same as R ０２ As the alkyl group, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, and a hydrogen atom or a methyl group is particularly preferred from the viewpoint of industrial availability.

[0128] In the formula (a-2), Va ０２ The divalent hydrocarbon group which may have an ether bond in the formula (I) may have a substituent.

[0129] Optionally substituted divalent hydrocarbon group: ０２When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0130] ...Va ０２ The aliphatic hydrocarbon group in the above means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0131] ...Straight-chain or branched-chain aliphatic hydrocarbon group The straight-chain aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ The branched chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched chain aliphatic hydrocarbon group, a branched chain alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0132] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, such as a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, or a carbonyl group.

[0133] ...Aliphatic hydrocarbon groups containing a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) that may contain a heteroatom-containing substituent in the ring structure, groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon groups include those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0134] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and even more preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. The cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure substituted with a substituent containing a heteroatom. The substituent containing a hetero atom includes —O—, —C(═O)—O—, —S—, and —S(═O) ２ -, -S(=O) ２ —O— is preferred.

[0135] ...Va ０２The aromatic hydrocarbon group in the above formula (1) is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene groups or heteroarylene groups); groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., groups in which one further hydrogen atom has been removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0136] In the aromatic hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0137] Va ０２ As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferred, a straight-chain alkylene group is more preferred, a straight-chain alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred.

[0138] In the formula (a-2), Ra ０２ is a lactone-containing cyclic group, —SO ２ -containing cyclic groups or carbonate-containing cyclic groups.

[0139] The lactone-containing cyclic group in the structural unit (a2), —SO ２ When the component (A1) is used to form a resist film, the -containing cyclic group or carbonate-containing cyclic group is effective in improving the adhesion of the resist film to the substrate. Furthermore, the presence of the structural unit (a2) provides effects such as appropriate adjustment of the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriate adjustment of the solubility during development, thereby improving lithography properties, etc.

[0140] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) that contains -O-C(=O)- within its ring skeleton. Counting the lactone ring as the first ring, a group that contains only a lactone ring is called a monocyclic group, while a group that contains other ring structures is called a polycyclic group regardless of the structures. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. There are no particular restrictions on the lactone-containing cyclic group in the structural unit (a2), and any group can be used. Specific examples include groups represented by any of the following general formulae (a2-r-1) to (a2-r-7).

[0141]

[0142] [In formulas (a2-r-1) to (a2-r-7), 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 —SO ２ A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), or an oxygen atom or a sulfur atom, n' is an integer of 0 to 2, and m' is 0 or 1. * represents a bond.

[0143] In the 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. Of these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. Ra' ２１ The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, ２１Examples of the alkyl groups include those mentioned as examples of the alkyl group in the above formula and an oxygen atom (—O—). ２１ Examples of the halogen atom in Ra' include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. ２１ As the halogenated alkyl group in the formula Ra′, ２１ Examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0144] Ra' ２１ In the formula, -COOR" and -OC(=O)R", R" are each a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO ２ The alkyl group in R″ may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms.

[0145] When R" is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and 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, tricyclo[5.2.1.02,6]decane, or tetracyclododecane.

[0146] Examples of the lactone-containing cyclic group in R" include the same as the groups represented by any one of the general formulae (a2-r-1) to (a2-r-7). Examples of the carbonate-containing cyclic group in R" include the same as the carbonate-containing cyclic group described below, and specific examples include groups represented by any one of the general formulae (ax3-r-1) to (ax3-r-3). -SO in R" ２ The -containing cyclic group includes the -SO group described below. ２ The same applies to the -containing cyclic group, and specific examples thereof include groups represented by any of the general formulae (a5-r-1) to (a5-r-4).

[0147] Ra' ２１ The hydroxyalkyl group in the formula (Ra') preferably has 1 to 6 carbon atoms. ２１ and a group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0148] In the general formulae (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms for A" is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between carbon atoms of the alkylene group, such as -O-CH ２ -, -CH ２ -O-CH ２ -, -S-CH ２ -, -CH ２ -S-CH ２ A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0149] Specific examples of the group represented by any one of general formulae (a2-r-1) to (a2-r-7) are listed below.

[0150]

[0151]

[0152] "-SO ２ -containing cyclic group" means a group having a -SO ２ represents a cyclic group containing a ring containing -, specifically, -SO ２ The sulfur atom (S) in - forms a part of the ring skeleton of the cyclic group. ２ The ring containing - is counted as the first ring, and when there is only this ring, it is called a monocyclic group, and when there is further ring structure, it is called a polycyclic group regardless of the structure. ２ The -containing cyclic group may be a monocyclic group or a polycyclic group. ２ The -containing cyclic group is particularly one that does not contain an -O-SO group in its ring skeleton. ２ Cyclic groups containing -, i.e., -O-SO ２ It is preferred that the —O—S— in — is a cyclic group containing a sultone ring forming part of the ring skeleton. ２ More specific examples of the -containing cyclic group include groups represented by any of the following general formulae (a5-r-1) to (a5-r-4).

[0153]

[0154] [In formulas (a5-r-1) to (a5-r-4), 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 —SO ２ 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. * represents a bond.

[0155] In the formulae (a5-r-1) and (a5-r-2), A" is the same as A" in the formulae (a2-r-2), (a2-r-3), and (a2-r-5). ５１The 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 selected from the group consisting of Ra′ ２１ Specific examples of the groups represented by formulae (a5-r-1) to (a5-r-4) are listed below. In the formulae, "Ac" represents an acetyl group.

[0156]

[0157]

[0158]

[0159] The term "carbonate-containing cyclic group" refers to a cyclic group containing a ring (carbonate ring) containing -O-C(=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 furthermore 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. There are no particular limitations on the carbonate-containing cyclic group, and any group can be used. Specific examples include groups represented by the following general formulae (ax3-r-1) to (ax3-r-3), respectively.

[0160]

[0161] [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 —SO ２ A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, or an oxygen atom or a sulfur atom, p' is an integer of 0 to 3, and q' is 0 or 1. * represents a bond.

[0162] 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). Ｘ３１ 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 selected from the group consisting of Ra′ ２１ Specific examples of the groups represented by general formulae (ax3-r-1) to (ax3-r-3) are listed below.

[0163]

[0164] Ra ０２ the lactone-containing cyclic group, —SO ２ Suitable examples of the -containing cyclic group and the carbonate-containing cyclic group include the groups represented by the above-mentioned general formulae (a2-r-1) to (a2-r-7), (a5-r-1) to (a5-r-4), and (ax3-r-1) to (ax3-r-3), respectively.

[0165] In the formula (a-2), Ra ０２ is, among the above, a lactone-containing cyclic group or —SO ２ -containing cyclic groups are preferred, and substituents represented by any of the general formulae (a2-r-1) to (a2-r-7) or (a5-r-1) to (a5-r-4) are preferred, groups represented by any of the general formulae (a2-r-1), (a2-r-2), (a2-r-6) and (a5-r-1) are more preferred, and groups represented by any of the general formulae (a2-r-1) or (a2-r-2) are even more preferred. Specifically, a group represented by any one of 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), and (r-s1-1-1) is preferred, and a group represented by any one of the chemical formulas (r-lc-1-1), (r-lc-1-2), (r-lc-2-1), (r-lc-2-12), or (r-s1-1-1) is more preferred.

[0166] The structural unit (a2) contained in the component (A1) may be of one type, or may be of two or more types. When the component (A1) contains the structural unit (a2), the proportion of the structural unit (a2) relative to the total (100 mol%) of all structural units constituting the component (A1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%. When the proportion of the structural unit (a2) is at least the preferred lower limit, the aforementioned effects achieved by including the structural unit (a2) can be fully obtained. When the proportion is at most the preferred upper limit, a balance with other structural units can be achieved, resulting in various favorable lithography properties.

[0167] <<Other Structural Units>> The component (A1) may further include other structural units in addition to the aforementioned structural units (a1) and (a2). Examples of other structural units include a structural unit (a3) ​​that includes a polar group-containing aliphatic hydrocarbon group. As the structural unit (a3), many of the structural units that are conventionally known to be used in resin components of resist compositions can be used, with the exception of those that correspond to the structural unit (a1) or the structural unit (a2).

[0168] 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 includes a polar group-containing aliphatic hydrocarbon group. When the component (A1) includes the structural unit (a3), the hydrophilicity of the component (A) is enhanced, contributing to improved resolution. Furthermore, the acid diffusion length can be appropriately adjusted.

[0169] Examples of polar groups include hydroxyl groups, cyano groups, carboxy groups, and hydroxyalkyl groups in which some of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms, with hydroxyl groups being particularly preferred. Examples of aliphatic hydrocarbon groups include linear or branched hydrocarbon groups (preferably alkylene groups) having 1 to 10 carbon atoms, and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be either a monocyclic group or a polycyclic group, and can be appropriately selected from the many groups proposed for use in resins for ArF excimer laser resist compositions, for example.

[0170] When the cyclic group is a monocyclic group, it more preferably has 3 to 10 carbon atoms. Among these, structural units derived from acrylate esters containing an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the alkyl group's hydrogen atoms are substituted with fluorine atoms are more preferred. Examples of such monocyclic groups 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, or cyclooctane. Of 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.

[0171] When the cyclic group is a polycyclic group, the polycyclic group more preferably has 7 to 30 carbon atoms. Among these, structural units derived from acrylate esters containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the alkyl group's hydrogen atoms are substituted with fluorine atoms are more preferred. Examples of such polycyclic groups include groups obtained by removing two or more hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc. Specific examples include groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane. Among these polycyclic groups, groups obtained by removing two or more hydrogen atoms from adamantane, groups obtained by removing two or more hydrogen atoms from norbornane, and groups obtained by removing two or more hydrogen atoms from tetracyclododecane are industrially preferred.

[0172] The structural unit (a3) ​​is not particularly limited, 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. When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the structural unit (a3) ​​is preferably a structural unit derived from a hydroxyethyl ester of acrylic acid. Furthermore, when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, preferred structural units for the structural unit (a3) ​​include structural units represented by the following formulas (a3-1), (a3-2), and (a3-3); when the hydrocarbon group is a monocyclic group, preferred structural units include structural units represented by formula (a3-4).

[0173]

[0174] [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, 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.]

[0175] In formulas (a3-1) to (a3-4), R represents R in general formula (a-1). ０１ It is the same as above. R is preferably a hydrogen atom or a methyl group. In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that hydroxyl groups are bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that hydroxyl groups are bonded to the 3rd position of the adamantyl group. It is preferable that j is 1, and it is particularly preferable that hydroxyl groups are bonded to the 3rd position of the adamantyl group.

[0176] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

[0177] 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.

[0178] 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.

[0179] The structural unit (a3) ​​contained in the component (A1) may be one type, or two or more types. When the component (A1) contains the structural unit (a3), the proportion of the structural unit (a3) ​​is preferably 1 to 30 mol %, more preferably 2 to 25 mol %, and even 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 (a3) ​​is at least the preferred lower limit, the effects achieved by including the structural unit (a3) ​​can be fully obtained due to the effects described above. By ensuring that the proportion is at most the preferred upper limit, a balance with the other structural units can be achieved, resulting in various favorable lithography properties.

[0180] Component (A1) can be produced by dissolving the monomers that derive each structural unit in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the solution and polymerizing. Alternatively, component (A1) can be produced by dissolving the monomer that derives structural unit (a1) and the monomer that derives structural unit (a2) in a polymerization solvent, and then adding a radical polymerization initiator such as those described above to the solution and polymerizing.

[0181] During polymerization, for example, HS-CH ２ -CH ２ -CH ２ -C(CF ３ ) ２By using a chain transfer agent such as —OH in combination, it is possible to obtain a chain with —C(CF ３ ) ２ A copolymer having a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group have been substituted with fluorine atoms is thus introduced, and is effective in reducing development defects and LER (line edge roughness: non-uniform irregularities on the line sidewalls).

[0182] In the resist composition according to the embodiment of the present invention, the weight average molecular weight (Mw) of the component (A1) (based on polystyrene standards measured by gel permeation chromatography (GPC)) must be 30,000 or greater, preferably 32,000 or greater, more preferably 33,000 or greater, and even more preferably 35,000 or greater. The Mw of the component (A1) is preferably 120,000 or less, more preferably 100,000 or less, and even more preferably 80,000 or less. The Mw of the component (A1) in the resist composition according to the embodiment of the present invention is preferably 32,000 to 120,000, more preferably 33,000 to 100,000, and even more preferably 35,000 to 80,000. When the Mw of the component (A1) is less than or equal to the preferred upper limit of this range, the component will have sufficient solubility in a resist solvent for use as a resist. When the Mw is at least the preferred lower limit of this range, the component will have good dry etching resistance, LWR (line width roughness), and LER.

[0183] The dispersity (Mw / Mn) of component (A1) is not particularly limited, but is preferably 1.0 or more, and preferably 4.0 or less, more preferably 3.0 or less, and particularly preferably 2.0 or less. The dispersity (Mw / Mn) of component (A1) is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Here, Mn represents the number average molecular weight.

[0184] Base Components Other Than Component (A1) The resist composition according to an embodiment of the present invention may also use, as the component (A), a base component other than the component (A1) described above, whose solubility in a developer changes upon the action of acid (hereafter referred to as "component (A2)"). There are no particular restrictions on the component (A2), and it may be arbitrarily selected from the many base components conventionally known for use in chemically amplified resist compositions. The component (A2) may be a polymeric or low molecular weight compound, and may be used either alone or in combination of two or more types.

[0185] The proportion of component (A1) in component (A) 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 even be 100% by mass, relative to the total mass of component (A). When this 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 more likely to be formed. The proportion of component (A1) in component (A) is not particularly limited, but can be, for example, 100% by mass or less.

[0186] In the resist composition according to an embodiment of the present invention, the content of the component (A) can be adjusted depending on factors such as the thickness of the resist film to be formed, and is not particularly limited, but is preferably at least 2 mass% and more preferably at least 3 mass% relative to the total mass (100 mass%) of the resist composition. There are no particular upper limits for the content of the component (A), as long as it is a concentration that allows for the formation of a resist film, but for example, it is preferably 10 mass% or less and more preferably 5 mass% or less.

[0187] <Acid Generator Component (B)> In addition to the component (A) described above and the component (D) described below, the resist composition according to an embodiment of the present invention may further contain an acid generator component (B) (hereinafter referred to as "component (B)") that generates acid upon exposure. The component (B) is not particularly limited, and any of the components that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl- or bisarylsulfonyldiazomethanes and poly(bissulfonyl)diazomethanes, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. The component (B) preferably includes a compound (B1) comprising an onium salt (hereinafter sometimes referred to as "component (B1)") or a compound (B2) comprising an onium salt (hereinafter sometimes referred to as "component (B2)").

[0188] <Component (B1)> The resist composition according to an embodiment of the present invention contains an acid generator component (B) that generates an acid upon exposure, and the acid generator component (B) may contain a compound (B1) represented by the following general formula (b-01) (hereinafter also referred to as acid generator (B1)):

[0189]

[0190] [In general formula (b-01), R ａ ~R ｃ each independently represent an at least partially fluorinated alkyl or cycloalkyl group, or R ａ ~R ｃ At least two of these may be bonded to form a fluorinated alkylene group. m represents an integer of 1 or more, and M ｍ＋ represents an m-valent organic cation.

[0191] In general formula (b-01), R ａ ~R ｃare each independently an at least partially fluorinated alkyl group (preferably having 1 to 8 carbon atoms) or cycloalkyl group (preferably having 3 to 8 carbon atoms), or R ａ ~R ｃ At least two of these are bonded to form a fluorinated alkylene group. As the compound that generates the acid represented by (b-01), those represented by the following formulae (P1) and (P2) are particularly preferred.

[0192]

[0193]

[0194] In formulas (P1) to (P2), R １ represents a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group (preferably having 1 to 10 carbon atoms), a linear or branched alkoxyl group (preferably having 1 to 10 carbon atoms), or a linear or branched alkoxycarbonyl group (preferably having 2 to 11 carbon atoms). ２ represents a linear or branched alkyl group (preferably having 1 to 10 carbon atoms), a linear or branched alkoxyl group (preferably having 1 to 10 carbon atoms), or a linear, branched, or cyclic alkanesulfonyl group (preferably having 1 to 10 carbon atoms). n is an integer of 0 to 2, and m is an integer of 0 to 10. In formula (P1), X represents a divalent group (preferably having 2 to 10 carbon atoms), and R ５ each independently represents a fluorinated alkyl group (preferably having 1 to 8 carbon atoms) or a fluorinated cycloalkyl group (preferably having 3 to 8 carbon atoms).

[0195] In (P2), R ３ independently represent a linear or branched alkyl group (preferably having 1 to 10 carbon atoms), an optionally substituted phenyl group, or a substituted naphthyl group; R ５ ' independently represents a linear or branched fluorinated alkyl group (preferably having 1 to 8 carbon atoms).

[0196] R １ , R ２ , or R ３In the above, preferred examples of the linear or branched alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, a t-butyl group, an n-pentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, an n-decyl group, etc. Of these alkyl groups, a methyl group, an ethyl group, an n-butyl group, and a t-butyl group are more preferred.

[0197] R １ or R ２ Preferred linear or branched alkoxyl groups having 1 to 10 carbon atoms in the formula (I) include, for example, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, 2-methylpropoxy, 1-methylpropoxy, t-butoxy, n-pentyloxy, neopentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, 2-ethylhexyloxy, n-nonyloxy, n-decyloxy, etc. Of these alkoxyl groups, methoxy, ethoxy, n-propoxy, and n-butoxy are more preferred.

[0198] R １ Preferred linear or branched alkoxycarbonyl groups having 2 to 11 carbon atoms in the formula (I) include, for example, a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, an n-butoxycarbonyl group, a 2-methylpropoxycarbonyl group, a 1-methylpropoxycarbonyl group, a t-butoxycarbonyl group, an n-pentyloxycarbonyl group, a neopentyloxycarbonyl group, an n-hexyloxycarbonyl group, an n-heptyloxycarbonyl group, an n-octyloxycarbonyl group, a 2-ethylhexyloxycarbonyl group, an n-nonyloxycarbonyl group, an n-decyloxycarbonyl group, etc. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, and an n-butoxycarbonyl group are more preferred.

[0199] R ２Preferred examples of the linear, branched, or cyclic alkanesulfonyl group having 1 to 10 carbon atoms include methanesulfonyl, ethanesulfonyl, n-propanesulfonyl, n-butanesulfonyl, tert-butanesulfonyl, n-pentanesulfonyl, neopentanesulfonyl, n-hexanesulfonyl, n-heptanesulfonyl, n-octanesulfonyl, 2-ethylhexanesulfonyl, n-nonanesulfonyl, n-decanesulfonyl, cyclopentanesulfonyl, and cyclohexanesulfonyl. Of these alkanesulfonyl groups, methanesulfonyl, ethanesulfonyl, n-propanesulfonyl, n-butanesulfonyl, cyclopentanesulfonyl, and cyclohexanesulfonyl are preferred. Furthermore, m is preferably 0 to 2.

[0200] R ３ Examples of the optionally substituted phenyl group in the formula (I) include phenyl groups such as phenyl, o-tolyl, m-tolyl, p-tolyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4,6-trimethylphenyl, 4-ethylphenyl, 4-t-butylphenyl, 4-cyclohexylphenyl, and 4-fluorophenyl, or phenyl groups substituted with a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; and groups in which these phenyl groups or alkyl-substituted phenyl groups are substituted with at least one group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonyloxy group.

[0201] Among the substituents on the phenyl group and the alkyl-substituted phenyl group, examples of the alkoxyl group include linear, branched, or cyclic alkoxyl groups having 1 to 20 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, a 1-methylpropoxy group, a t-butoxy group, a cyclopentyloxy group, and a cyclohexyloxy group. Examples of the alkoxyalkyl group include linear, branched, or cyclic alkoxyalkyl groups having 2 to 21 carbon atoms, such as a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group, and a 2-ethoxyethyl group. Examples of the alkoxycarbonyl group include linear, branched, or cyclic alkoxycarbonyl groups having 2 to 21 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, i-propoxycarbonyl, n-butoxycarbonyl, 2-methylpropoxycarbonyl, 1-methylpropoxycarbonyl, t-butoxycarbonyl, cyclopentyloxycarbonyl, and cyclohexyloxycarbonyl. Examples of the alkoxycarbonyloxy group include linear, branched, or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms, such as methoxycarbonyloxy, ethoxycarbonyloxy, n-propoxycarbonyloxy, i-propoxycarbonyloxy, n-butoxycarbonyloxy, t-butoxycarbonyloxy, cyclopentyloxycarbonyl, and cyclohexyloxycarbonyl. ３ Among the optionally substituted phenyl groups in the above, preferred are a phenyl group, a 4-cyclohexylphenyl group, a 4-t-butylphenyl group, a 4-methoxyphenyl group, and a 4-t-butoxyphenyl group.

[0202] R ３Examples of the optionally substituted naphthyl group in the formula (I) include a 1-naphthyl group, a 2-methyl-1-naphthyl group, a 3-methyl-1-naphthyl group, a 4-methyl-1-naphthyl group, a 4-methyl-1-naphthyl group, a 5-methyl-1-naphthyl group, a 6-methyl-1-naphthyl group, a 7-methyl-1-naphthyl group, an 8-methyl-1-naphthyl group, a 2,3-dimethyl-1-naphthyl group, a 2,4-dimethyl-1-naphthyl group, a 2,5-dimethyl-1-naphthyl group, a 2,6-dimethyl-1-naphthyl group, a 2,7-dimethyl-1-naphthyl group, a 2,8-dimethyl-1-naphthyl group, a 3,4-dimethyl-1-naphthyl group, a 3,5-dimethyl-1-naphthyl group, a 3,6-dimethyl-1-naphthyl group, a 3,7 naphthyl groups such as 1-dimethyl-1-naphthyl, 3,8-dimethyl-1-naphthyl, 4,5-dimethyl-1-naphthyl, 5,8-dimethyl-1-naphthyl, 4-ethyl-1-naphthyl, 2-naphthyl, 1-methyl-2-naphthyl, 3-methyl-2-naphthyl, and 4-methyl-2-naphthyl, or naphthyl groups substituted with a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; and groups in which these naphthyl groups or alkyl-substituted naphthyl groups are substituted with at least one group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonyloxy group. Examples of the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, and alkoxycarbonyloxy group, which are the substituents, include the groups exemplified above for the phenyl group and the alkyl-substituted phenyl group. R ３ The optionally substituted naphthyl group in R is preferably a 1-naphthyl group, a 1-(4-methoxynaphthyl) group, a 1-(4-ethoxynaphthyl) group, a 1-(4-n-propoxynaphthyl) group, a 1-(4-n-butoxynaphthyl) group, a 2-(7-methoxynaphthyl) group, a 2-(7-ethoxynaphthyl) group, a 2-(7-n-propoxynaphthyl) group, or a 2-(7-n-butoxynaphthyl) group. ３ As the alkyl group, a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, and a 1-naphthyl group are preferred.

[0203] X represents a divalent group having 2 to 10 carbon atoms, and the divalent group having 2 to 10 carbon atoms is preferably a group that forms a 5- or 6-membered ring, particularly preferably a 5-membered ring (i.e., a tetrahydrothiophene ring) together with the sulfur atom in formula (P1). Furthermore, examples of substituents on the divalent group include the hydroxyl group, carboxyl group, cyano group, nitro group, alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, and alkoxycarbonyloxy group, all of which are exemplified as substituents on the phenyl group and alkyl-substituted phenyl group. X is preferably a divalent group that forms a tetrahydrothiophene ring structure together with the sulfur atom.

[0204] R ５ , and R ５ Examples of the fluorinated alkyl group having 1 to 8 carbon atoms represented by ' include perfluoro or partially fluorinated alkyl groups, such as trifluoromethyl group, pentafluoroethyl group, heptafluoro-n-butyl group, heptafluoro-i-propyl group, nonafluoro-n-butyl group, nonafluoro-2-methylpropyl group, nonafluoro-1-methylpropyl group, nonafluoro-t-butyl group, perfluoro-n-pentyl group, perfluoroneopentyl group, perfluoro-n-hexyl group, perfluoro-n-heptyl group, and perfluoro-n-octyl group.

[0205] Preferable examples of the cationic moiety of the acid generator (B1) represented by formula (P1) or (P2) include the following compounds.

[0206]

[0207]

[0208] Preferable examples of the anion moiety of the acid generator (B1) represented by formula (P1) or (P2) include the following compounds.

[0209]

[0210] All combinations of the above cationic moieties and anionic moieties can be preferably used. In addition, sulfonium salts represented by the following formula are preferred.

[0211]

[0212]

[0213]

[0214]

[0215]

[0216]

[0217] Among the above, particularly preferred sulfonium salts are B1-1 to B1-3 and B1-19 to B1-21, and particularly preferred sulfonium salts are B1-1 and B1-19.

[0218] The component (B1) may be used alone or in combination with other components. The component (B1) is preferably contained in an amount of 1 to 60 mass %, more preferably 2.5 to 50 mass %, and particularly preferably 5 to 30 mass %, based on the total solid content of the composition.

[0219] <Component (B2)> Furthermore, the resist composition according to an embodiment of the present invention contains an acid generator component (B) that generates an acid upon exposure, and the acid generator component (B) may contain a compound (B2) represented by the following general formula (b-02):

[0220]

[0221] [In general formula (b-02), Rf ０１ and Rf ０２ each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group; Rf ０１ , Rf ０２ At least one of the groups contains a fluorine atom. X represents a divalent linking group. Y represents a cyclic group which may have a substituent. m represents an integer of 1 or more, and M ｍ＋ represents an m-valent organic cation.

[0222] [anion moiety (Y-X-C(Rf ０１ ) (Rf ０２ )-SO ３ － )] In the general formula (b-02), Y-X-C(Rf０１ ) (Rf ０２ )-SO ３ － is a counter anion. There are no particular restrictions on the counter anion, and any of the anions proposed as an anion moiety of an acid generator for a chemically amplified resist composition can be used.

[0223] In general formula (b-02), Rf ０１ and Rf ０２ each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group.

[0224] Rf ０１ and Rf ０２ The fluorinated alkyl groups represented by the formula (I) may each independently be chain-like or cyclic, and are preferably linear or branched. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4.

[0225] Specific examples include groups in which some or all of the hydrogen atoms constituting a linear alkyl group, 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, or a decyl group, have been substituted with fluorine atoms, and groups in which some or all of the hydrogen atoms constituting a branched alkyl group, such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, or a 3-methylbutyl group, have been substituted with fluorine atoms. ０１ and Rf ０２ The fluorinated alkyl groups represented by Rf may each independently contain an atom other than a fluorine atom, a carbon atom, or a hydrogen atom, such as an oxygen atom, a sulfur atom, or a nitrogen atom. ０１ and Rf ０２ The fluorinated alkyl group represented by is preferably a group in which some or all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atoms, and is preferably a group in which all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atoms (perfluoroalkyl group).

[0226] In general formula (b-02), Rf ０１ and Rf０２ Preferably, each represents a fluorine atom.

[0227] In general formula (b-02), X represents a divalent linking group, and is preferably a divalent linking group containing an oxygen atom. When X is a divalent linking group containing an oxygen atom, X may contain an atom other than an oxygen atom. Examples of atoms other than an oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.

[0228] Examples of divalent linking groups containing an oxygen atom include non-hydrocarbon oxygen atom-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-O-C(=O)-O-); and combinations of such non-hydrocarbon oxygen atom-containing linking groups with alkylene groups. These combinations may further include a sulfonyl group (-SO ２ -) may be linked. Examples of such a divalent linking group containing an oxygen atom include linking groups represented by the following general formulae (y-a1-1) to (y-a1-7). In the following general formulae (y-a1-1) to (y-a1-7), the group that bonds to Y in the above general formula (b-02) is V' in the following general formulae (y-a1-1) to (y-a1-7). １０１ is.

[0229]

[0230] [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.

[0231] 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.

[0232] V ’１０１ and V' １０２The alkylene group in may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group. ’１０１ Specific examples of the alkylene group in V'102 include a methylene group [-CH ２ -]; -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; ethylene groups [-CH ２ CH ２ -]; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CCH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, etc.; a trimethylene group (n-propylene group) [—CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ an alkyltrimethylene group such as -; a tetramethylene group [-CH ２ CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH２ CH ２ -, etc.; an alkyltetramethylene group such as a pentamethylene group [—CH ２ CH ２ CH ２ CH ２ CH ２ -] etc. ’１０１ or V' １０２ In the formula (a1-r-1), some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by Ra' in the formula (a1-r-1). ３ A divalent group obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group) of the above formula (I) is preferred, and a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferred.

[0233] X is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably a linking group represented by any one of the above formulas (y-al-1) to (y-al-5).

[0234] In general formula (b-02), Y represents a cyclic group which may have a substituent. The cyclic group which may have a substituent is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group which does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0235] The aromatic hydrocarbon group for Y is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring in the aromatic hydrocarbon group for Y include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic hydrocarbon group for Y include groups in which one hydrogen atom has been removed from the aromatic ring (aryl groups: for example, phenyl group, naphthyl group, etc.), and groups in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 or 2, and particularly preferably 1.

[0236] Examples of the cyclic aliphatic hydrocarbon group represented by Y include aliphatic hydrocarbon groups containing a ring in their structure. The cyclic aliphatic hydrocarbon group represented by Y preferably has 3 to 50 carbon atoms, preferably 4 to 45 carbon atoms, and more preferably 5 to 40 carbon atoms. Examples of the aliphatic hydrocarbon group containing a ring in its structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a bridged ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton such as a cyclic group having a steroid skeleton.

[0237] Among these, the cyclic aliphatic hydrocarbon group for Y is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0238] Among the cyclic aliphatic hydrocarbon groups represented by Y, specific preferred examples are listed below. * indicates a bond.

[0239]

[0240] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ -] and the like. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0241] The cyclic hydrocarbon group for Y may contain a heteroatom, such as a heterocycle. Specifically, the cyclic hydrocarbon group for Y may be a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7), a —SO 2 group represented by each of the general formulae (a5-r-1) to (a5-r-4), ２ -containing cyclic groups, and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16), respectively, in which * represents a bond bonded to X in general formula (b-02).

[0242]

[0243] Examples of substituents in the cyclic group represented by Y include alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxy groups, carbonyl groups, and nitro groups. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, with methyl, ethyl, propyl, n-butyl, and tert-butyl groups being most preferred. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, with methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, and tert-butoxy being more preferred, with methoxy and ethoxy being most preferred. Examples of halogen atoms as a substituent include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms being preferred. Examples of halogenated alkyl groups as a substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the halogen atoms. The carbonyl group as a substituent is a methylene group (-CH ２ -) is a group that substitutes

[0244] The cyclic hydrocarbon group for Y may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a bridged ring polycyclic skeleton to which one or more aromatic rings are fused. Specific examples of the bridged ring polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. Specific examples of the fused ring group for Y include those represented by the following formulae (r-br-1) to (r-br-2). In the formulae, * represents a bond bonded to X in general formula (b-02).

[0245]

[0246] Examples of the substituent that the fused cyclic group for Y may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group. Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused cyclic group include the same groups as those exemplified as the substituent of the cyclic group for Y. Examples of the aromatic hydrocarbon group as the substituent of the fused cyclic group include groups in which one hydrogen atom has been removed from an aromatic ring (aryl groups: for example, phenyl group, naphthyl group, etc.), groups in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of the alicyclic hydrocarbon group as a substituent of the fused cyclic group include groups in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane; groups in which one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane or tetracyclododecane; lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7), respectively; -SO represented by the general formulae (a5-r-1) to (a5-r-4), respectively; ２ -containing cyclic group: heterocyclic groups represented by the above formulae (r-hr-7) to (r-hr-16), respectively.

[0247] The cyclic hydrocarbon group for Y may be a group in which two or more aliphatic rings and / or aromatic rings are linked by a linear or branched aliphatic hydrocarbon group which may have a substituent. The linear or branched aliphatic hydrocarbon group linking the alicyclic hydrocarbon groups is preferably a group in which a methylene group (-CH ２ -) may be substituted with a divalent group containing a hetero atom. Examples of the divalent group containing a hetero atom include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -S-, and -S(=O) ２-, -S(=O) ２ -O- and the like.

[0248] Among the above, Y is preferably an alicyclic hydrocarbon group which may have a substituent, a group in which one or more hydrogen atoms have been removed from a polycycloalkane which may have a substituent, or —SO ２ A -containing cyclic group is more preferred, and an adamantyl group which may have a hydroxy group or —SO ２ -containing cyclic groups are more preferred.

[0249] X is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably a linking group represented by any one of the above formulae (y-al-1) to (y-al-5), and still more preferably a linking group represented by the above formula (y-al-1) or (y-al-3).

[0250] Specific examples of the anion moiety represented by general formula (b-02), when X is a single bond, include fluorinated alkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; and when X is a divalent linking group containing an oxygen atom, include anions represented by the following formulas (an-1) to (an-3), respectively.

[0251]

[0252] [In the formula, R” １０１ R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by any one of the above chemical formulas (r-hr-1) to (r-hr-6), or a fused cyclic group represented by the above formula (r-br-1) or (r-br-2). １０２ represents 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 any one of the above general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or —SO ２ -containing cyclic group. １０３V" is an aromatic cyclic group which may have a substituent, or an aliphatic cyclic group which may have a substituent. １０１ is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; each v" is independently an integer of 0 to 3; each q" is independently an integer of 0 to 20; and each n" is independently 0 or 1.

[0253] R” １０１ , R” １０２ and R” １０３ The aliphatic cyclic group which may have a substituent is preferably a group exemplified as the cyclic aliphatic hydrocarbon group for Y in general formula (b-02). Examples of the substituent include the same as the substituent which may substitute the cyclic aliphatic hydrocarbon group for Y in general formula (b-02).

[0254] R” １０３ The aromatic cyclic group which may have a substituent in the formula (b-02) is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the formula (b-02) (Y). Examples of the substituent include the same as the substituent which may substitute the aromatic hydrocarbon group in the formula (b-02) (Y).

[0255] Among the anions in the general formula (b-02), anions represented by any one of the general formulae (an-1) to (an-3) are more preferred, anions represented by any one of the general formulae (an-1) or (an-2) are even more preferred, and anions represented by the general formula (an-1) are particularly preferred.

[0256] Specific examples of the anion represented by general formula (b-02) are shown below, but are not limited to these.

[0257]

[0258]

[0259] [Cation moiety: (M ｍ＋ ) １／ｍ ] In the general formula (b1-1), Mｍ＋ represents an m-valent organic cation. ｍ＋ The organic cation in the formula (I) is preferably an onium cation, more preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and even more preferably a sulfonium cation or an iodonium cation, and m is an integer of 1 or more.

[0260] Preferred cationic moieties ((M ｍ＋ ) １／ｍ ) includes organic cations represented by any one of the following general formulas (ca-1) to (ca-3).

[0261]

[0262] [In general formulas (ca-1) to (ca-3), R ２０１ ~R ２０７ each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, R ２０１ ~R ２０３ , R ２０６ ~R ２０７ may be bonded to each other to form a ring together with the sulfur atom in the formula. ２０８ ~R ２０９ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R ２１０ represents an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ２ -containing cyclic group, and L ２０１ represents —C(═O)— or —C(═O)—O—.]

[0263] R ２０１ ~R ２０７ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２０１ ~R ２０７ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７The alkenyl group in R preferably has 2 to 10 carbon atoms. ２０１ ~R ２０７ 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, an arylthio group, and a group represented by any of the following formulae (car-r-1) to (car-r-7). The aryl group in the arylthio group as a substituent includes an aryl group having 6 to 20 carbon atoms, and a phenyl group, a naphthyl group, and a biphenyl group are preferred. Examples of the arylthio group include a phenylthio group, a naphthylthio group, and a biphenylthio group.

[0264]

[0265] [In the formula, R' ２０１ are each independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

[0266] R' ２０１ The optionally substituted cyclic group represented by is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Examples of aromatic hydrocarbon groups include aromatic hydrocarbon rings or aryl groups in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings, with phenyl and naphthyl groups being preferred. Examples of aliphatic hydrocarbon groups include groups in which one hydrogen atom has been removed from a monocycloalkane or polycycloalkane, with adamantyl and norbornyl being preferred.

[0267] R' ２０１The optionally substituted chain alkyl group represented by the formula (I) 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 decyl 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.

[0268] R' ２０１ The optionally substituted chain alkenyl group represented by may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl, propenyl (allyl), and butenyl groups. Examples of branched alkenyl groups include 1-methylpropenyl and 2-methylpropenyl groups. Of the above, the propenyl group is particularly preferred as the chain alkenyl group.

[0269] R' ２０１ Examples of the optionally substituted cyclic group or optionally substituted chain alkyl group represented by the formula (I) include the same as those of the acid-dissociable group described above.

[0270] R' ２０１Examples of the substituent in the cyclic group, chain-like alkyl group, or chain-like alkenyl group represented by the formula (I) include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, 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 a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, in which some or all of the hydrogen atoms have been substituted with the halogen atoms.

[0271] R ２０１ ~R ２０３ , R ２０６ ~R ２０７ When they are bonded to each other to form a ring together with the sulfur atom in the formula, they are not substituted with heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, or with carbonyl groups, -SO-, -SO ２ -, -SO ３ -, -COO-, -CONH- or -N(R Ｎ )-(the R Ｎ is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and a thioxanium ring.

[0272] R２０８ ~R ２０９ R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ２０８ ~R ２０９ When each of these independently represents an alkyl group, they may be bonded to each other to form a ring.

[0273] R ２１０ represents an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ２ -containing cyclic group. ２１０ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２１０ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２１０ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２１０ -SO which may have a substituent ２ In the -containing cyclic group, "-SO ２ -containing cyclic group" means a group having a -SO ２ represents a cyclic group containing a ring containing -, specifically, -SO ２ The sulfur atom (S) in - forms a part of the ring skeleton of the cyclic group. ２ The ring containing - is counted as the first ring, and when there is only this ring, it is called a monocyclic group, and when there is further ring structure, it is called a polycyclic group regardless of the structure. ２ The -containing cyclic group may be a monocyclic group or a polycyclic group. ２ The -containing cyclic group is particularly one that does not contain an -O-SO group in its ring skeleton. ２ Cyclic groups containing -, i.e., -O-SO ２ It is preferable that the —O—S— in — is a cyclic group containing a sultone ring forming part of the ring skeleton. ２１０ -SO which may have a substituent ２The -containing cyclic group is preferably a group represented by the above formula (a5-r-1). ２１０ The substituents that may be possessed by R ２０１ ~R ２０７ The cation represented by formula (ca-1) is preferably a cation represented by the following formula (b-2):

[0274]

[0275] [In formula (b-2), Rb ２０１ ~Rb ２０２ represents an aryl group which may have a substituent, Rb ２０３ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ２０１ ~Rb ２０３ may be bonded to each other to form a ring together with the sulfur atom in formula (b-2).

[0276] Rb ２０１ ~Rb ２０２ The optionally substituted aryl group represented by the above R ２０１ ~R ２０７ The preferred examples of Rb are the same as those of the aryl group optionally having a substituent. ２０３ The optionally substituted aryl group, optionally substituted alkyl group or optionally substituted alkenyl group represented by the above R ２０１ ~R ２０７ The meanings of the optionally substituted aryl group, the optionally substituted alkyl group, and the optionally substituted alkenyl group are the same as those of the optionally substituted aryl group, the optionally substituted alkyl group, and the preferred examples are also the same.

[0277] Specific examples of suitable cations represented by formula (ca-1) include cations represented by any of the following formulas (ca-1-1) to (ca-1-67).

[0278]

[0279]

[0280]

[0281] [In the formula, g1, g2, and g3 represent the number of repeating units, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[0282]

[0283] [In the formula, R” ２０１ is a hydrogen atom or a substituent, and the substituent is the same as R ２０１ ~R ２０７ , and R ２１０ The substituents are the same as those exemplified as the substituents that may be possessed by

[0284] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by any of the following formulas (ca-3-1) to (ca-3-6).

[0285]

[0286] In the resist composition according to one embodiment of the present invention, the component (B2) may be used either as a single type, or as a combination of two or more types.

[0287] In the resist composition according to an embodiment of the present invention, the amount of component (B2) relative to 100 parts by mass of component (A) is preferably 1 to 60 parts by mass, more preferably 2.5 to 50 parts by mass, and even more preferably 5 to 30 parts by mass. When the amount of component (B2) is at least as large as the lower limit of this preferred range, lithography properties such as reduced roughness and increased sensitivity are further improved. On the other hand, when the amount is at most as large as the upper limit, a resist pattern with excellent exposure latitude is more easily formed.

[0288] Regarding Component (B3), the resist composition according to an embodiment of the present invention may contain an acid generator component (hereafter referred to as "component (B3)") other than component (B1) or (B2), as long as the effects of the present invention are not impaired. There are no particular limitations on the component (B3), and any of the components that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl- or bisarylsulfonyldiazomethanes and poly(bissulfonyl)diazomethanes, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0289] In the resist composition according to one embodiment of the present invention, the component (B3) may be used alone, or two or more types may be used in combination. When the resist composition contains the component (B3), the amount of the component (B3) in the resist composition is preferably 30 parts by mass or less, and more preferably 1 to 25 parts by mass, per 100 parts by mass of the component (A). By ensuring that the amount of the component (B3) in the resist composition falls within the above range, sufficient pattern formation is achieved. Furthermore, when the components of the resist composition are dissolved in an organic solvent, a homogeneous solution is easily obtained, which is preferable because the storage stability of the resist composition is improved.

[0290] In the resist composition according to an embodiment of the present invention, the amount of acid generator component (B) is preferably 1 to 40 parts by mass, more preferably 2.5 to 30 parts by mass, and even more preferably 5 to 25 parts by mass, per 100 parts by mass of base component (A). By ensuring that the amount of acid generator component (B) in the resist composition falls within the above range, it becomes easier to obtain a resist composition that exhibits excellent stability over time, and it also becomes easier to form a resist pattern that exhibits both a wide exposure latitude and high sensitivity to an exposure light source.

[0291] <Acid Diffusion Control Component (D)> In addition to the component (A), the resist composition according to an embodiment of the present invention further contains an acid diffusion control component (D). The acid diffusion control component (D) (component (D)) acts as a quencher (acid diffusion controller) that traps acid generated in the resist composition upon exposure. The component (D) may be, for example, a photodegradable base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure and loses its acid diffusion control properties, or a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of component (D1). However, component (D1) is preferred. By using a resist composition that contains the component (D), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern.

[0292] Regarding the Component (D1): By using a resist composition containing the component (D1), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. The component (D1) may be used as an acid generator in addition to or in place of the component (B). The component (D1) is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion controllability, and is preferably one or more compounds selected from the group consisting of compounds represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)") and compounds represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"). The components (d1-1) and (d1-2) decompose and lose their acid diffusion controllability (basicity) in the exposed areas of the resist film, and therefore do not function as quenchers, but function as quenchers in the unexposed areas of the resist film.

[0293]

[0294] [In general formula (d1-1) and general formula (d1-2), Rd １ and Rd ２ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２In the formula (I), no fluorine atom is bonded to the carbon atom adjacent to the S atom. m is an integer of 1 or more, and M ｍ＋ are each independently an m-valent organic cation.

[0295] {Component (d1-1)} Anion portion In formula (d1-1), Rd １ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of the R' ２０１ Among these, Rd １ is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group, 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 connected via an alkylene group, and in this case, the substituent is preferably a linking group represented by any of the above formulas (y-al-1) to (y-al-5).

[0296] 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). More preferred examples of the aliphatic cyclic group include a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include straight-chain alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched-chain alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0297] When the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, and nitrogen atoms. Rd １ As the alkyl group, a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms is preferred, and a fluorinated alkyl group in which all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms (linear perfluoroalkyl group) is particularly preferred.

[0298] Specific examples of preferred anion moieties of component (d1-1) are shown below.

[0299]

[0300] Cation moiety In formula (d1-1), M ｍ＋ is an m-valent organic cation. ｍ＋Suitable examples of the organic cation include the same as the cation represented by any one of the general formulae (ca-1) to (ca-3), with the cation represented by the general formula (ca-1) being more preferred, and the cation represented by any one of the general formulae (ca-1-1) to (ca-1-67) being even more preferred. One type of component (d1-1) may be used alone, or two or more types may be used in combination.

[0301] {Component (d1-2)} Anion portion In formula (d1-2), Rd ２ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and ２０１ However, Rd ２ In the formula, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not substituted with fluorine). This makes the anion of component (d1-2) an appropriately weak acid anion, improving the quenching ability of component (D). ２ is preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. The aliphatic cyclic group is more preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor, or the like. Rd ２ The hydrocarbon group may have a substituent, and the substituent may be Rd １ Examples of the substituents include the same as those that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0302] Specific examples of preferred anion moieties of component (d1-2) are shown below.

[0303]

[0304]

[0305] Cation moiety In formula (d1-2), M ｍ＋ is an m-valent organic cation, and M in the formula (d1-1) ｍ＋ The component (d1-2) may be used alone or in combination of two or more.

[0306] The component (D1) may be any one of the above components (d1-1) and (d1-2), 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, relative to 100 parts by mass of the component (A), is preferably 0.5 to 25 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 2.5 to 15 parts by mass. When the amount of the component (D1) is at least as large as the preferred lower limit, particularly favorable lithography properties and resist pattern shape are more likely to be obtained. On the other hand, when the amount is at most as large as the upper limit, good sensitivity can be maintained and excellent throughput can also be achieved.

[0307] Production method of component (D1): The production method of the components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods, for example, in the same manner as the method described in U.S. Patent Publication No. 2012-0149916.

[0308] Regarding the component (D2), the component (D) may contain, as an acid diffusion controller, 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 controller and does not fall under the category of the component (D1), and any known component may be used. Among these, aliphatic amines or aromatic amines are preferred, and aromatic amines are more preferred.

[0309] The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of the aliphatic amine include ammonia NH ３and cyclic amines, in which at least one hydrogen atom is substituted with an alkyl group having 12 or less carbon atoms or a hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines). Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0310] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of aliphatic monocyclic amines include piperidine and piperazine. Specific examples of aliphatic polycyclic amines include those having 6 to 10 carbon atoms, such as 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0311] 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.

[0312] Furthermore, the component (D2) may be an aromatic amine, such as 4-dimethylaminopyridine, 2,6-di-tert-butylpyridine, pyrrole, indole, pyrazole, imidazole, or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, or N-tert-butoxycarbonylpyrrolidine.

[0313] The component (D2) may be used singly, or in combination of two or more types. When the resist composition contains the component (D2), the amount of the component (D2) within the resist composition is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A). By ensuring that the amount is within this range, the resist pattern shape and stability over time during storage can be improved.

[0314] <Optional Components> The resist composition according to an embodiment of the present invention may further contain components (optional components) other than the above-described components (A) and (D). Examples of such optional components include the above-described component (B), and the following components (E), (F), and (S).

[0315] <Component (E): At Least One Compound Selected from the Group Consisting of Organic Carboxylic Acids, Phosphorus Oxoacids, and Derivatives Thereof> The resist composition according to an embodiment of the present invention may contain, as an optional component, at least one compound (E) (hereinafter referred to as "component (E)") selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and derivatives thereof, for the purposes of preventing sensitivity degradation and improving resist pattern shape and post-exposure stability. Suitable organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, and isophthalic acid. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred. Derivatives of phosphorus oxoacids include esters in which the hydrogen atoms of the above oxoacids are substituted with hydrocarbon groups, and examples of such 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 phosphonic acid ester, di-n-butyl phosphonic acid ester, phenylphosphonic acid, diphenyl phosphonic acid ester and dibenzyl phosphonic acid ester. Examples of the derivatives of phosphinic acid include phosphinic acid ester and phenylphosphinic acid.

[0316] Of the above, component (E) is preferably an organic carboxylic acid, more preferably an aromatic carboxylic acid, specifically benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, or isophthalic acid, more preferably salicylic acid.

[0317] In the resist composition according to an embodiment of the present invention, the component (E) may be used either as a single type, or as a combination of two or more types. When the resist composition contains the component (E), the amount of the component (E) relative to 100 parts by mass of the component (A) is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass.

[0318] <Component (F): Fluorine Additive Component> The resist composition of this embodiment may contain a fluorine additive component (hereafter referred to as "component (F)") as a hydrophobic resin. The component (F) is used to impart water repellency to the resist film, and when used as a resin separate from the component (A), it improves lithography properties. Examples of the component (F) that can be used include the fluorine-containing polymer compounds described in JP 2010-002870, JP 2010-032994, JP 2010-277043, JP 2011-13569, and JP 2011-128226. More specific examples of the component (F) include polymers having a structural unit (f11) represented by the following general formula (f1-1):

[0319] The polymer having the structural unit (f11) represented by the following general formula (f1-1) is preferably a polymer (homopolymer) consisting solely of the structural unit (f11) represented by the following formula (f1-1), a copolymer of the structural unit (f11) with the structural unit (a1), or a copolymer of the structural unit (f11), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a3). Here, the structural unit (a1) copolymerized with the structural unit (f11) is preferably a structural unit containing an acid-dissociable group represented by the above formula (a1-r2-1).

[0320]

[0321] [wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. １０２ and Rf １０３ Rf each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; １０２ and Rf １０３ may be the same or different. １ is an integer of 0 to 5, and Rf １０１ is an organic group containing a fluorine atom.

[0322] In general formula (f1-1), R bonded to the carbon atom at the α-position is R in general formula (a-1). ０１ R is preferably a hydrogen atom or a methyl group. １０２ and Rf １０３ Examples of the halogen atom in Rf include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. １０２ and Rf １０３ Examples of the alkyl group having 1 to 5 carbon atoms in Rf include the same alkyl groups having 1 to 5 carbon atoms as those in R, and a methyl group or an ethyl group is preferred. １０２ and Rf １０３ Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being particularly preferred. １０２ and Rf １０３ is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group. ｆ１ is an integer of 0 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

[0323] In general formula (f1-1), Rf １０１ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. In addition, the hydrocarbon group containing a fluorine atom is preferably one in which 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more, because this increases the hydrophobicity of the resist film during immersion exposure. Among these, Rf １０１is preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, more preferably a trifluoromethyl group, —CH ２ -CF ３ , -CH ２ -CF ２ -CF ３ , -CH(CF ３ ) ２ , -CH ２ -CH ２ -CF ３ , -CH ２ -CH ２ -CF ２ -CF ２ -CF ２ -CF ３ is more preferred, and —CH ２ -CF ３ is particularly preferred.

[0324] The weight average molecular weight (Mw) of component (F) (based on polystyrene standards measured by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. When the weight average molecular weight is at or below the upper limit of this range, the resist composition of this embodiment will have sufficient solubility in a resist solvent for use as a resist, while when the weight average molecular weight is at or above the lower limit of this range, the resist composition of this embodiment will exhibit excellent dry etching resistance and a favorable resist pattern cross-sectional shape. The dispersity (Mw / Mn) of component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0325] In the resist composition of this embodiment, the component (F) may be used either as a single type, or as a combination of two or more types. When the resist composition contains the component (F), the component (F) is typically used in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the component (A).

[0326] <Organic Solvent Component (S)> The resist composition according to this embodiment of the present invention can be produced by dissolving a resist material in an organic solvent component (hereafter referred to as "component (S)"). The component (S) can be any solvent that is capable of dissolving the various components used and forming a homogeneous solution, and any solvent can be appropriately selected from among those conventionally known as solvents for chemically amplified resist compositions. In the resist composition according to this embodiment of the present invention, the component (S) can be used either alone or as a mixed solvent of two or more different solvents. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0327] Also preferred as component (S) is a mixed solvent of PGMEA and a polar solvent. The blending ratio (mass ratio) can be determined appropriately taking into account the compatibility of PGMEA with the polar solvent, etc. Another preferred component (S) is a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5. The amount of component (S) used is not particularly limited and is appropriately determined based on the coating film thickness and a concentration that allows application to a substrate, etc. Component (S) is generally used so that the solids concentration of the resist composition is within the range of 0.1 to 20 mass%, preferably 0.2 to 15 mass%.

[0328] The resist composition of this embodiment may further contain, as desired, compatible additives such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, and dyes.

[0329] A resist composition according to an embodiment of the present invention contains the above-described component (A) and component (D), and, if necessary, the above-described optional components. Suitable examples include resist compositions containing the component (A), component (B), and component (D). Furthermore, suitable examples include resist compositions containing the component (A), component (B), component (D), and component (F).

[0330] As described above, the resist composition according to an embodiment of the present invention comprises a base component (A) that includes the aforementioned polymeric compound (A1) having a weight-average molecular weight of 30,000 or more, and an acid diffusion control component (D). It is presumed that by including a compound having a specific structure, the acid diffusion control component (D) in the resist composition can efficiently undergo salt exchange with the strong acid derived from the acid generator, thereby enabling the formation of a resist pattern with excellent LWR.

[0331] [Method of Forming a Resist Pattern] A method of 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 of the above-described embodiment, exposing the resist film to light, and developing the resist film to form a resist pattern. One embodiment of this method of forming a resist pattern is, for example, a method of forming a resist pattern carried out as follows.

[0332] First, the resist composition of the above-described embodiment is applied to a support using a spinner or the like, and baked (post-applied bake (PAB)) for 40 to 120 seconds, preferably 50 to 90 seconds, at a temperature of 80 to 150°C to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an EUV exposure device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with electron beams without a mask pattern. The resist film is then baked (post-exposure bake (PEB)) for 40 to 120 seconds, preferably 50 to 90 seconds, at a temperature of 80 to 150°C. Next, the resist film is developed. In the case of an alkali development process, the development is performed using an alkaline developer, and in the case of a solvent development process, a developer containing an organic solvent (organic developer). After the development, a rinse treatment is preferably performed. In the case of an alkaline development process, the rinse treatment is preferably a water rinse using pure water, and in the case of a solvent development process, a rinse solution containing an organic solvent is preferably used. In the case of a solvent development process, after the development treatment or rinse treatment, a treatment may be performed using a supercritical fluid to remove the developer or rinse solution adhering to the pattern. After the development treatment or rinse treatment, drying is performed. In addition, in some cases, a bake treatment (post-bake) may be performed after the development treatment.

[0333] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, examples include silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold.

[0334] 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, or soft X-ray can be used.

[0335] The exposure method for the resist film may be a normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be liquid immersion exposure (liquid immersion lithography), but liquid immersion exposure is preferred. Liquid immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure apparatus is filled in advance with a solvent (immersion medium) having a refractive index higher than that of air, and exposure (immersion exposure) is performed in this state. The liquid immersion medium is preferably a solvent having a refractive index higher than that of air but lower than that of the resist film to be exposed. The refractive index of such a solvent is not particularly limited as long as it is within the above-mentioned range. Examples of solvents having a refractive index higher than that of air but lower than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Water is preferably used as the liquid immersion medium.

[0336] An example of an alkaline developer used in the development treatment in an alkaline development process is a 0.1 to 10% by weight aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in a solvent development process may be any solvent capable of dissolving component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents. Ketone solvents are organic solvents containing C-C(=O)-C or C-C(=O)-H in their structure. Ester solvents are organic solvents containing C-C(=O)-O-C or H-C(=O)-O-C in their structure. Alcohol solvents are organic solvents containing an alcoholic hydroxyl group in their structure. An "alcoholic hydroxyl group" refers to a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile solvents are organic solvents containing a nitrile group in their structure. Amide-based solvents are organic solvents containing an amide group in their structure. Ether-based solvents are organic solvents containing a C—O—C group in their structure. Some organic solvents contain multiple functional groups characteristic of the above-mentioned solvents in their structure. In such cases, the term "organic solvent" refers to any solvent containing the functional groups possessed by the organic solvent. For example, diethylene glycol monomethyl ether is considered to fall under both the alcohol-based solvent and the ether-based solvent in the above classification. Hydrocarbon-based solvents are hydrocarbon solvents that are composed of optionally halogenated hydrocarbons and do not contain any substituents other than halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms being preferred. Among the above, polar solvents are preferred as organic solvents contained in organic developers, and ketone-based solvents, ester-based solvents, nitrile-based solvents, and the like are preferred.

[0337] Examples of the ester solvent include methyl acetate, butyl acetate, and ethyl acetate.

[0338] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0339] The organic developer may contain known additives as needed. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants.

[0340] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), or a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0341] The organic solvent contained in the rinse solution used in the rinsing treatment after development in the solvent development process can be appropriately selected from the organic solvents listed above as organic solvents used in the organic developer, as long as they do not easily dissolve the resist pattern. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used alone or in combination with two or more. They may also be used in combination with other organic solvents or water.

[0342] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method, such as a method of continuously applying the rinse solution onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse solution for a certain period of time (dipping method), or a method of spraying the rinse solution onto the surface of the support (spray method).

[0343] The resist composition of the above-described embodiment and the various materials used in the pattern formation method of the above-described embodiment (e.g., resist solvent, developer, rinse, anti-reflective coating composition, top coat composition, etc.) preferably do not contain impurities such as metals, halogen-containing metal salts, acids, alkalis, or components containing sulfur or phosphorus atoms. Examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0344] In the method of forming a resist pattern according to the embodiment of the present invention described above, the resist composition according to the embodiment of the present invention is used, and therefore a resist pattern with excellent roughness reduction properties can be formed.

[0345] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0346] Each polymer compound was synthesized using monomers that derive the structural units constituting the polymer compounds (A)-1 to (A)-19 and (A)-X1 to (A)-X5 shown below in a predetermined molar ratio. １３ The copolymerization composition ratio of the polymer compound (the proportion (molar ratio) of each structural unit in the polymer compound) determined by C-NMR, and the weight average molecular weight (Mw) and polydispersity index (PDI) (Mw / Mn) calculated in terms of standard polystyrene determined by GPC measurement are also shown.

[0347]

[0348]

[0349]

[0350]

[0351]

[0352]

[0353] <Preparation of Resist Compositions> (Examples 1 to 36, Comparative Examples 1 to 6) The components shown in Tables 1 and 2 were mixed.

[0354]

[0355]

[0356] In Tables 1 and 2, the abbreviations have the following meanings. A-1 to A-19: The above-mentioned polymer compounds (A)-1 to (A)-19. A-X1 to A-X5: The above-mentioned polymer compounds (A)-X1 to (A)-X5. B-1 to B-7: Acid generators comprising compounds represented by the following chemical formulas (B)-1 to (B)-7. D-1 to D-8: Acid diffusion controllers comprising compounds represented by the following chemical formulas (D)-1 to (D)-8. D-X1: Acid diffusion controller comprising a compound represented by the following chemical formula (D)-X1. F-1: Hydrophobic resin F-1 containing the following structural unit (composition ratio (molar ratio): l / m = 80 / 20, Mw: 25,000, Mw / Mn: 1.5). S-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / cyclohexanone in a mass ratio of 55 / 20 / 25.

[0357]

[0358]

[0359]

[0360]

[0361] <Formation of Resist Pattern> An organic antireflective coating composition "ARC95" (manufactured by Brewer Science) was applied onto a 12-inch silicon wafer using a spinner, and then baked on a hot plate at 205°C for 60 seconds to dry, thereby forming an organic antireflective coating with a thickness of 90 nm. Further, a resist composition was applied onto the above antireflective coating using a spinner, and then prebaked (PAB) on a hot plate at 80°C for 60 seconds and dried, thereby forming a resist film with a thickness of 110 nm.

[0362] The wafer was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (6% halftone) using an XT1900Gi ArF immersion exposure system (manufactured by ASML; NA (numerical aperture) = 1.35, Dipole 90X, Sigma (Ont 0.97, In 0.78) TE-pol, immersion medium: ultrapure water). Then, a PEB treatment was performed at 90°C for 60 seconds.

[0363] Next, alkaline development was performed for 10 seconds using a 2.38% by mass aqueous solution of TMAH (trade name: NMD-W, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C, followed by rinsing with pure water for 15 seconds and then shaking off and drying. As a result, in each example, a 1:1 line and space (LS) pattern with a line width of 60 nm and a pitch of 120 nm was formed.

[0364] [Evaluation of LWR (Line Width Roughness)] For the LS pattern formed in the above <Formation of Resist Pattern>, 3σ, a measure of LWR, was determined. "3σ" refers to triple the standard deviation (σ) (unit: nm) obtained from the measurement results of 400 line positions measured in the longitudinal direction of the line using a critical dimension SEM (scanning electron microscope, accelerating voltage 500 V, product name: CG6300, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the smaller the roughness of the line sidewall, meaning that an LS pattern with a more uniform width was obtained.

[0365] From the results shown in Table 1, it was confirmed that the resist compositions of the examples were all more effective in reducing roughness than the resist compositions of the comparative examples.

[0366] In the resist compositions of Comparative Examples 1 to 3, the polymeric compounds (A)-X1 to (A)-X3 contained in the base component (A) had weight-average molecular weights of less than 30,000. Therefore, the resist compositions of Comparative Examples 1 to 3 were inferior in roughness reduction ability to the resist compositions of Examples 1 to 4, which contained polymeric compounds (A)-1 to (A)-4 each having a weight-average molecular weight of 30,000 or more and which were composed of the same structural units.

[0367] The resist composition of Comparative Example 4 used the compound (D)-X1 which does not have a specific structure instead of the component (D1) which has a specific structure as an acid diffusion controller, and therefore was inferior in terms of roughness reduction properties compared to the resist compositions of the examples.

[0368] The resist compositions of Comparative Examples 5 and 6 used polymer compounds (A)-X4 and (A)-X5, respectively, which did not have the specific structure instead of the component (A1) having the specific structure as the polymer compound contained in the base component (A). Therefore, compared to the resist compositions of the Examples, the roughness reduction properties were inferior.

[0369] According to the present invention, it is possible to provide a resist composition capable of forming a resist pattern that exhibits excellent roughness reduction, and a method of forming a resist pattern using the resist composition.

[0370] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2023-148431) filed on September 13, 2023, the contents of which are incorporated herein by reference.

Claims

1. A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; and an acid diffusion control component (D), wherein the base component (A) comprises a polymer compound (A1) having a weight average molecular weight of 30,000 or more, the polymer compound (A1) having a structural unit (a1) represented by the following general formula (a-1) and a structural unit (a2) represented by the following general formula (a-2), and the acid diffusion control component (D) comprises one or more compounds (D1) selected from the group consisting of compounds represented by the following general formula (d1-1) and compounds represented by the following general formula (d1-2): [In general formula (a-1), R ０１ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ is a divalent hydrocarbon group which may have an ether bond. ａ０１ is an integer from 0 to 2. ０１ is an acid dissociable group. [In general formula (a-2), R ０２ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０２ is a divalent hydrocarbon group which may have an ether bond. ａ０２ is an integer from 0 to 2. ０２ is a lactone-containing cyclic group, -SO ２ -containing cyclic group, or carbonate-containing cyclic group. [In general formula (d1-1) and general formula (d1-2), Rd １ and Rd ２ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula (I), no fluorine atom is bonded to the carbon atom adjacent to the S atom. m is an integer of 1 or more, and M ｍ＋ are each independently an m-valent organic cation.

2. The resist composition according to claim 1, further comprising an acid generator component (B) (excluding the compound (D1)) that generates an acid upon exposure.

3. The resist composition according to claim 2, wherein the acid generator component (B) includes a compound (B1) represented by the following general formula (b-01): [In general formula (b-01), R ａ ~R ｃ each independently represents an at least partially fluorinated alkyl or cycloalkyl group, or R ａ ~R ｃ At least two of the groups may be bonded to each other to form a fluorinated alkylene group. m represents an integer of 1 or more, M ｍ＋ represents an m-valent organic cation.

4. The resist composition according to claim 2, wherein the acid generator component (B) includes a compound (B2) represented by the following general formula (b-02): [In general formula (b-02), Rf ０１ and Rf ０２ each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group; Rf ０１ , Rf ０２ At least one of X and Y represents a divalent linking group. Y represents a cyclic group which may have a substituent. m represents an integer of 1 or more, M ｍ＋ represents an m-valent organic cation.

5. The Ra in the general formula (a-2) ０２ is a substituent represented by any one of the following formulas (a2-r-1) to (a2-r-7) or (a5-r-1) to (a5-r-4): [In formulas (a2-r-1) to (a2-r-7), 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 -SO ２ -containing cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom; n' is an integer of 0 to 2, and m' is 0 or 1. * represents a bond. [In formulas (a5-r-1) to (a5-r-4), 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 -SO ２ -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; n' is an integer of 0 to 2. * represents a bond.

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

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