Resist composition and resist pattern forming method

Abstract

The present invention provides: a resist composition which ensures high sensitivity and from which a resist pattern having good roughness-reducing properties can be formed; and a resist pattern forming method using said resist composition. The present invention relates to a resist composition which generates an acid when exposed and of which the solubility in a developer changes due to the action of the acid, the resist composition comprising: a main material component (A) of which the solubility in a developer changes due to the action of an acid; an acid generator component (B) that generates an acid when exposed; a first acid diffusion control component (D1); and a second acid diffusion control component (D2), wherein the acid generator component (B) includes a compound represented by general formula (B1-1) disclosed in the specification, the first acid diffusion control component (D1) includes a compound represented by general formula (d1-1) or (d1-2) disclosed in the specification, and the second acid diffusion control component (D2) includes a compound represented by general formula (d2-1) 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] However, there is a trade-off between sensitivity and lithography properties such as roughness reduction. The base resin used as a substrate component in a chemically amplified resist composition generally has multiple structural units in order to improve lithography properties. For example, Patent Document 1 (JP-A-2003-102666) discusses a resist composition and a method for forming a resist pattern that can achieve high sensitivity and also form a resist pattern with good roughness reduction. Patent Document 1 also describes a resist composition that uses two photodegradable bases with specific structures.

[0006] Japanese Patent Application Publication No. 2022-95120

[0007] As lithography technology continues to advance and resist patterns become increasingly finer, resist compositions are required to have even higher sensitivity and 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 that enables the formation of a resist pattern that exhibits high sensitivity and favorable roughness reduction, and a method of forming a resist pattern that uses 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 an acid upon exposure, and whose solubility in a developer changes due to the action of the acid, and includes a base component (A) whose solubility in a developer changes due to the action of the acid, an acid generator component (B) that generates an acid upon exposure, a first acid diffusion control component (D1), and a second acid diffusion control component (D2), wherein the acid generator component (B) includes a compound represented by the following general formula (b1-1):

[0012]

[0013] [In general formula (b1-1), R １ ~R ３ are each independently an at least partially fluorinated alkyl or cycloalkyl group, or R １ ~R ３ At least two of these may be bonded to form a fluorinated alkylene group. m is an integer of 1 or more, and M ｍ＋ is an m-valent organic cation.

[0014]

[0015] [In general formula (d1-1) and general formula (d1-2), Rd １１ and Rd １２ X represents a linear or cyclic aliphatic hydrocarbon group which may have a substituent. １ and X ２ are each independently a heteroatom or a methylene group which may have a substituent. １ and n ２ are each independently an integer of 1 to 10. m is each independently an integer of 1 or more, and M ｍ＋ are each independently an m-valent organic cation.

[0016]

[0017] [In formula (d2-1), Rd ２is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O); m is an integer of 1 or more; M ｍ＋ is 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 able to provide a resist composition that enables the formation of a resist pattern that exhibits high sensitivity and favorable roughness reduction, and a method of forming a resist pattern that uses 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 ２The 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, an acid generator component (B) (hereinafter also referred to as "component (B)") that generates acid upon exposure, a first acid diffusion control component (D1) (hereinafter also referred to as "component (D1)"), and a second acid diffusion control component (D2) (hereinafter also referred to as "component (D2)"). The acid generator component (B) includes a compound represented by general formula (b1-1) below. The first acid diffusion control component (D1) includes a compound represented by general formula (d1-1) or (d1-2) below. The second acid diffusion control component (D2) includes a compound represented by general formula (d2-1) below.

[0029]

[0030] [In general formula (b1-1), R １ ~R ３ are each independently an at least partially fluorinated alkyl or cycloalkyl group, or R １ ~R ３ At least two of these may be bonded to form a fluorinated alkylene group. m is an integer of 1 or more, and M ｍ＋ is an m-valent organic cation.

[0031]

[0032] [In general formula (d1-1) and general formula (d1-2), Rd １１ and Rd １２ X represents a linear or cyclic aliphatic hydrocarbon group which may have a substituent. １ and X ２ are each independently a heteroatom or a methylene group which may have a substituent. １ and n ２ are each independently an integer of 1 to 10. m is each independently an integer of 1 or more, and M ｍ＋ are each independently an m-valent organic cation.

[0033]

[0034] [In formula (d2-1), Rd ２ is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O); m is an integer of 1 or more; M ｍ＋ is 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] In the resist composition according to an embodiment of the present invention, the acid generator component (B) that generates acid upon exposure contains a compound represented by general formula (b1-1) having a specific structure, and the first acid diffusion control component (D1) and the second acid diffusion control component (D2) each contain compounds having specific structures. Therefore, when used to form a resist film, the resist composition is effective in improving the roughness reduction of the resist film. Furthermore, in an alkaline development process, the sensitivity of the resist film to an alkaline developer is increased during development. The anion of the compound having a specific structure contained in component (B) exhibits high acid strength, and the synergistic effect of using components (D1) and (D2) containing compounds having specific structures improves 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 achieve high sensitivity and form a resist pattern that exhibits excellent roughness reduction.

[0038] <Component (A)> In the resist composition of this embodiment, the component (A) is a base component whose solubility in a developer changes under the action of an acid, and the component (A) preferably includes a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes under the action of an acid. 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 (A1), the polarity of the base component (A) changes before and after exposure, so that good development contrast can be obtained not only in an alkaline development process but also in a solvent development process. At least the component (A1) is used as the component (A), and other polymeric compounds and / or low molecular weight compounds may be used in combination with the component (A1).

[0039]

[0013] When an alkaline development process is applied, the base component (A) containing the component (A1) is poorly soluble in an alkaline developer before exposure, and when an acid is generated from the component (B) upon exposure, the polarity of the base component (A) increases due to the action of the acid, thereby increasing its 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.

[0040] On the other hand, when a solvent development process is applied, the base component (A) containing the component (A1) is highly soluble in organic developers before exposure, and when an acid is generated from the component (B) upon exposure, the polarity of the base component (A) increases due to the action of the acid, thereby reducing its solubility in organic developers. 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 sparingly 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.

[0041] The base component (A) preferably contains a polymeric compound (A1) having a structural unit (a1) represented by the following general formula (a-1): As the component (A1), it is preferable to use a polymeric compound having a structural unit (a1) represented by general formula (a-1), and in addition to the structural unit (a1), a lactone-containing cyclic group, —SO ２ It is more preferable to use a polymeric compound having a structural unit (a2) that includes a -containing cyclic group or a carbonate-containing cyclic group.

[0042] In the resist composition according to an embodiment of the present invention, as the component (A1), one type of compound may be used alone, or two or more types may be used in combination.

[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. ０１ The 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 thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferred. R ０１ 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 most preferred from the viewpoint of industrial availability.

[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 ０１The 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 ) ５ The branched chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched chain aliphatic hydrocarbon group, a branched chain alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ )２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[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, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ]decane, tetracyclododecane, and the like.

[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 aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic aliphatic 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, and tricyclo[5.2.1.0]. ２，６ ]decane, tetracyclododecane, and the like.

[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] Examples of the chain alkenyl group include linear or branched alkenyl groups, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylpropenyl group and a 2-methylpropenyl group. Of the above chain alkenyl groups, a propenyl group is particularly preferred.

[0070] The cyclic alkenyl group preferably has 3 to 10 carbon atoms.

[0071] Ra' ４ ~Ra' ６When 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.

[0072] Ra' ４ ~Ra' ６ When 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.

[0073] 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.

[0074] 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

[0075] Ra' ５ and Ra' ６ and 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):

[0076]

[0077] [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.

[0078] In the above formula (a1-r2-1), Ra ０３１ 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.

[0079] 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.

[0080] 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.

[0081] In the formula (a1-r2-2), the alicyclic hydrocarbon group formed by Xa together with Ya is preferably a monocyclic alicyclic hydrocarbon group. ０In 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.

[0082] 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.

[0083] 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.

[0084] In the formula (a1-r2-3), the alicyclic hydrocarbon group formed by Xaa together with Yaa is preferably a monocyclic alicyclic hydrocarbon group. ０ In the formula (a1-r2-3), Ra １０４Examples of the aromatic hydrocarbon group in the formula (I) include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. １０４ is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0085] 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.

[0086] 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.

[0087] In formula (a1-r2-4), Ra' １４is an alicyclic hydrocarbon group, and is preferably a monocyclic alicyclic hydrocarbon group which may have a substituent. １４ Examples 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.

[0088] 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.

[0089] Specific examples of the group represented by the formula (a1-r2-1) are listed below: In the following formula, * represents a bond.

[0090]

[0091]

[0092] Specific examples of the group represented by the formula (a1-r2-2) are listed below: In the following formula, * represents a bond.

[0093]

[0094]

[0095]

[0096] Specific examples of the group represented by the formula (a1-r2-3) are listed below: In the following formula, * represents a bond.

[0097]

[0098] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0099]

[0100] 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").

[0101]

[0102] [In the formula, Ra' ７ ~Ra' ９ Each represents an alkyl group.

[0103] 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.

[0104] 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).

[0105] In the structural unit (a1), general formula (a-1) is preferably represented by the following general formula (a1-2):

[0106]

[0107] (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 having 1 to 10 carbon atoms, and Yab ０ represents a carbon atom. ０ is Yab ０represents 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.

[0108] 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:

[0109] In general formula (a1-2), na ３ is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0110] In general formula (a1-2), Ra ０３１ is as mentioned above.

[0111] 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.

[0112] 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:

[0113] Specific examples of the structural unit (a1) are listed below. α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120] ​

[0121]

[0122]

[0123]

[0124] 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.

[0125] <Structural Unit (a2)> The structural unit (a2) is a structural unit represented by the following general formula (a-2): It is preferable that the polymeric compound (A1) further contains a structural unit (a2) represented by the following general formula (a-2).

[0126]

[0127] [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.

[0128] In the formula (a-2), R ０２ is R in the general formula (a-1). ０１ It is the same as R ０２As 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.

[0129] 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.

[0130] Optionally substituted divalent hydrocarbon group: ０２ When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0131] ...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.

[0132] ...Straight-chain or branched-chain aliphatic hydrocarbon group The straight-chain aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５The branched chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched chain aliphatic hydrocarbon group, a branched chain alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0133] 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.

[0134] ...Aliphatic hydrocarbon groups containing a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) that may contain a heteroatom-containing substituent in the ring structure, groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon groups include those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ]decane, tetracyclododecane, and the like.

[0135] 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.

[0136] ...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.

[0137] 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.

[0138] 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.

[0139] In the formula (a-2), Ra ０２ is a lactone-containing cyclic group, —SO ２ -containing cyclic groups or carbonate-containing cyclic groups.

[0140] 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.

[0141] 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).

[0142]

[0143] [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.

[0144] 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.

[0145] 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.

[0146] When R" is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane; more specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ] groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as decane and tetracyclododecane.

[0147] 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).

[0148] 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.

[0149] 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.

[0150] Specific examples of groups represented by any of the general formulae (a2-r-1) to (a2-r-7) and other lactone-containing cyclic groups are listed below.

[0151]

[0152]

[0153] "-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).

[0154]

[0155] [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.

[0156] 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 group represented by any one of formulas (a5-r-1) to (a5-r-4) are listed below. In the formula, "Ac" represents an acetyl group.

[0157]

[0158]

[0159]

[0160] 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 any of the following general formulae (ax3-r-1) to (ax3-r-3).

[0161]

[0162] [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.

[0163] 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 group represented by any one of general formulae (ax3-r-1) to (ax3-r-3) are listed below.

[0164]

[0165] Ra ０２ the lactone-containing cyclic group, —SO ２ Suitable examples of the -containing cyclic group and the carbonate-containing cyclic group include a group represented by any one of the above-mentioned general formulae (a2-r-1) to (a2-r-7), a group represented by any one of the general formulae (a5-r-1) to (a5-r-4), and a group represented by any one of the general formulae (ax3-r-1) to (ax3-r-3), respectively.

[0166] 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.

[0167] 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.

[0168] <<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) ​​containing a polar group-containing aliphatic hydrocarbon group; and a structural unit (a4) containing an acid-non-dissociable aliphatic cyclic group. As the structural unit (a3) ​​and the structural unit (a4), many of the structural units conventionally known as those used in resin components of resist compositions can be used, with the exception of those corresponding to the structural unit (a1) or the structural unit (a2).

[0169] 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.

[0170] During polymerization, for example, HS-CH ２ -CH ２ -CH ２ -C(CF ３ ) ２ By using a chain transfer agent such as —OH in combination, it is possible to obtain a chain with —C(CF ３ ) ２A 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).

[0171] The weight average molecular weight (Mw) of component (A1) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited, but is preferably from 1,000 to 50,000, more preferably from 2,000 to 30,000, and even more preferably from 3,000 to 20,000. When the Mw of component (A1) is equal to or less than the preferred upper limit of this range, the component will have sufficient solubility in a resist solvent for use as a resist, while when the Mw is equal to or greater than the preferred lower limit of this range, the component will have good dry etching resistance and the cross-sectional shape of the resist pattern.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] <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 further contains an acid generator component (B) (hereinafter also referred to as “component (B)”) that generates acid upon exposure. The acid generator component (B) includes a compound represented by the following general formula (b1-1):

[0177]

[0178] [In general formula (b1-1), R １ ~R ３ are each independently an at least partially fluorinated alkyl or cycloalkyl group, or R １ ~R ３ At least two of these may be bonded to form a fluorinated alkylene group. m is an integer of 1 or more, and M ｍ＋ is an m-valent organic cation.

[0179] [Anion moiety] In general formula (b1-1), R １ ~R ３are 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 １ ~R ３ At least two of R are bonded to each other to form a fluorinated alkylene group. １ ~R ３ and preferably each independently represent a fluorinated alkyl group (preferably having 1 to 8 carbon atoms) or a fluorinated cycloalkyl group (preferably having 3 to 8 carbon atoms).

[0180] R １ ~R ３ Examples of the fluorinated alkyl group represented by the formula (I) include perfluoro or partially fluorinated alkyl groups, such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoro-n-butyl group, a heptafluoro-n-propyl group, a heptafluoro-i-propyl group, a nonafluoro-n-butyl group, a nonafluoro-2-methylpropyl group, a nonafluoro-1-methylpropyl group, a nonafluoro-t-butyl group, a perfluoro-n-pentyl group, a perfluoroneopentyl group, a perfluoro-n-hexyl group, a perfluoro-n-heptyl group, and a perfluoro-n-octyl group.

[0181] R １ ~R ３ Examples of the fluorinated cycloalkyl group represented by the formula (I) include groups in which at least one hydrogen atom of a cycloalkyl group has been substituted with a fluorine atom (fluorocycloalkyl group), such as 3- to 20-membered fluorocycloalkyl groups such as monofluorocyclopentyl, difluorocyclopentyl, nonafluorocyclopentyl, monofluorocyclohexyl, difluorocyclohexyl, and undecafluorocyclohexyl. The fluorocycloalkyl group is preferably a 5- to 20-membered ring, and more preferably a 5- to 15-membered ring.

[0182] R １ ~R ３Examples of the fluorinated alkylene group having at least two of the above bonded thereto include perfluoro or partially fluorinated alkylene groups, such as difluoromethylene group, tetrafluoroethylene group, hexafluoro-n-propylene group, hexafluoro-i-propylene group, octafluoro-n-butylene group, octafluoro-2-methylpropylene group, octafluoro-1-methylpropylene group, octafluoro-t-butylene group, perfluoro-n-pentylene group, perfluoroneopentylene group, perfluoro-n-hexylene group, perfluoro-n-heptylene group, and perfluoro-n-octylene group.

[0183] Preferable examples of the anion moiety of the compound represented by general formula (b1-1) include the following compounds.

[0184]

[0185] [Cation moiety: (M ｍ＋ ) １／ｍ ] In the general formula (b1-1), M ｍ＋ 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.

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

[0187]

[0188] [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 ２０７may 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—.]

[0189] R ２０１ ~R ２０７ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２０１ ~R ２０７ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２０１ ~R ２０７ 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.

[0190]

[0191] [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.

[0192] R' ２０１The 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.

[0193] R' ２０１ The 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.

[0194] 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.

[0195] 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.

[0196] R' ２０１ Examples 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.

[0197] 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.

[0198] R ２０８ ~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.

[0199] 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 substituent２ The -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 Examples of the substituents that may be possessed by the group include:

[0200] The cation represented by formula (ca-1) is preferably a cation represented by the following general formula (b-2): ｍ＋ is preferably a cation represented by the following general formula (b-2).

[0201]

[0202] [In general formula (b-2), Rb ２０１ ~Rb ２０３ Rb each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ２０１ ~Rb ２０３ may be bonded to each other to form a ring together with the sulfur atom in general formula (b-2).

[0203] Rb ２０１ ~Rb ２０３ The optionally substituted aryl group, optionally substituted alkyl group, and optionally substituted alkenyl group represented by the formula (I) are each the same as those described above for R ２０１ ~R ２０７ The aryl group which may have a substituent, the alkyl group which may have a substituent, and the alkenyl group which may have a substituent are defined as the above, and preferred examples are also the same.

[0204] Specific examples of suitable cations represented by formula (ca-1) include cations represented by any of the following formulas (ca-1-1) to (ca-1-70).

[0205]

[0206]

[0207]

[0208] [In the formula, g1, g2, and g3 represent the number of repeating units, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 1 to 20.]

[0209]

[0210] [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

[0211]

[0212] 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).

[0213]

[0214] As the compound represented by general formula (b1-1), all combinations of the above-mentioned cationic moieties and anionic moieties can be preferably used. Furthermore, as the compound represented by general formula (b1-1), for example, a sulfonium salt represented by the following formula is preferred.

[0215]

[0216]

[0217]

[0218]

[0219]

[0220] Of the above, preferred sulfonium salts are B1-1 to B1-4 and B1-9 to B1-13, and particularly preferred sulfonium salts are B1-1 to B1-4.

[0221] Furthermore, the component (B) may be used alone, or a combination of two or more components may be used. In the resist composition of this embodiment, the amount of the component (B) relative to 100 parts by mass of the component (A) is preferably 1 to 60 parts by mass, more preferably 2.5 to 50 parts by mass, and particularly preferably 5 to 20 parts by mass.

[0222] <Acid Diffusion Control Component (D)> In addition to the components (A) and (B), the resist composition according to an embodiment of the present invention further comprises a first acid diffusion control component (D1) and a second acid diffusion control component (D2). The first acid diffusion control component (D1) comprises a compound represented by the following general formula (d1-1) or (d1-2), and the second acid diffusion control component (D2) comprises a compound represented by the following general formula (d2-1). The first acid diffusion control component (D1) (hereinafter referred to as "component (D1)") and the second acid diffusion control component (D2) (hereinafter referred to as "component (D2)") act as quenchers (acid diffusion controllers) that trap acid generated in the resist composition upon exposure. By using a resist composition containing the components (D1) and (D2), it is possible to further improve the contrast between exposed and unexposed areas of the resist film when forming a resist pattern. The components (D1) and (D2) may be used as acid generators in addition to or instead of the component (B). The components (D1) and (D2) may also be, for example, photodecomposable bases that decompose upon exposure and lose their ability to control acid diffusion.

[0223] <First Acid Diffusion Control Component (D1)> In addition to the component (A) and the component (B), the resist composition of this embodiment further includes a first acid diffusion control component (D1) and a second acid diffusion control component (D2) that control the diffusion of acid generated from the component (B) upon exposure. The component (D1) includes a compound represented by the following general formula (d1-1) (hereinafter also referred to as "compound (d1-1)") or a compound represented by the following general formula (d1-2) (hereinafter also referred to as "compound (d1-2)").

[0224] <Compound (d1-1)> The compound (d1-1) is a compound represented by the following general formula (d1-1).

[0225]

[0226] [In general formula (d1-1), Rd １１ X represents a linear or cyclic aliphatic hydrocarbon group which may have a substituent. １ is a methylene group which may have a heteroatom or a substituent. １ is an integer of 1 to 10. m is an integer of 1 or more, and M ｍ＋ is an m-valent organic cation.

[0227] [Anion moiety] In the above general formula (d1-1), Rd １１ is a chain or cyclic aliphatic hydrocarbon group which may have a substituent. The chain aliphatic hydrocarbon group is specifically a straight-chain or branched-chain aliphatic hydrocarbon group.

[0228] Rd １１ The aliphatic hydrocarbon group in may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group, but is preferably a saturated aliphatic hydrocarbon group.

[0229] Rd １１ Specific examples of the linear or branched aliphatic hydrocarbon group in the formula (I) include linear or branched saturated hydrocarbon groups (alkyl groups) and linear or branched unsaturated hydrocarbon groups.

[0230] The linear or branched alkyl group is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, and more preferably a linear or branched alkyl group having 1 to 10 carbon atoms. Specific examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a linear or branched butyl group, a linear or branched pentyl group, a linear or branched hexyl group, a linear or branched heptyl group, a linear or branched octyl group, a linear or branched nonyl group, and a linear or branched decyl group. Of the above, the linear or branched alkyl group is preferably a linear alkyl group having 1 to 10 carbon atoms, and more preferably a linear alkyl group having 5 to 10 carbon atoms.

[0231] Some of the carbon atoms constituting the chain aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, and -S(=O) ２ -, -S(=O) ２ —O— is preferred.

[0232] More specific examples of the unsaturated hydrocarbon group in the linear or branched unsaturated hydrocarbon group include unsaturated hydrocarbon groups having a double bond, such as alkenyl groups, alkadienyl groups, and alkatrienyl groups; and unsaturated hydrocarbon groups having a triple bond, such as alkynyl groups, groups in which one hydrogen atom has been removed from a dialkyne, and groups in which one hydrogen atom has been removed from a trialkyne.

[0233] Specific examples of the linear or branched alkenyl group include linear alkenyl groups such as a vinyl group, a propenyl group (allyl group), and a 2-butenyl group; and branched alkenyl groups such as a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.

[0234] Specific examples of the alkadienyl group include a propadienyl group and a butadienyl group, etc. Specific examples of the alkatrienyl group include a butatrienyl group, etc.

[0235] Specific examples of the straight-chain or branched-chain alkynyl group include straight-chain alkynyl groups such as ethynyl, propargyl, and 3-pentynyl groups; and branched-chain alkynyl groups such as 1-methylpropargyl group.

[0236] Specific examples of the group in which one hydrogen atom has been removed from a dialkyne include a group in which one hydrogen atom has been removed from a diacetylene, etc. Specific examples of the group in which one hydrogen atom has been removed from a trialkyne include a group in which one hydrogen atom has been removed from a hexa-1,3,5-triyne, etc.

[0237] Rd １１ Specific examples of the cyclic aliphatic hydrocarbon group in the formula (I) include monocyclic alicyclic groups and polycyclic alicyclic groups.

[0238] As the monocyclic alicyclic group, a group in which one hydrogen atom has been removed from a monocycloalkane or a monocycloalkene is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The monocycloalkene is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentene and cyclohexene. As the polycyclic alicyclic group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane is preferred, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclo[5.2.1.0], ２，６ ] Polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as decane and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton, are more preferred.

[0239] Rd １１ The cyclic aliphatic hydrocarbon group in may contain a heteroatom such as a heterocycle. Specifically, a lactone-containing cyclic group represented by any one of the general formulae (a2-r-1) to (a2-r-7) above, a —SO ２ -containing cyclic groups, and heterocyclic groups represented by any of the following chemical formulas (r-hr-7) to (r-hr-16). In each formula, * represents a bond bonded to the carbon atom of the carbonyl group in general formula (d1-1).

[0240]

[0241] Rd １１Examples of the substituent that the linear or cyclic aliphatic hydrocarbon group in the formula (I) may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, and an oxygen atom (═O). 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, and an iodine atom, and a fluorine atom is 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. The phrase "having an oxygen atom (=O) as a substituent" means that two hydrogen atoms bonded to one carbon atom constituting the aliphatic hydrocarbon group are substituted with an oxygen atom (=O). Also, the term "having an oxygen atom (=O) as a substituent" means that two hydrogen atoms bonded to one carbon atom constituting the aliphatic hydrocarbon group are substituted with an oxygen atom (=O). ２ -) is substituted with a carbonyl group.

[0242] In the above general formula (d1-1), Rd １１ is preferably a cyclic aliphatic hydrocarbon group which may have a substituent, more preferably a cyclic aliphatic hydrocarbon group having an oxygen atom (═O), and even more preferably a polycyclic alicyclic group having an oxygen atom (═O).

[0243] In the above general formula (d1-1), X １ is a heteroatom or a methylene group which may have a substituent, and is preferably a heteroatom. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom, and an oxygen atom (—O—) is preferred. When the methylene group has a substituent, examples of the substituent include Rd １１Examples of the substituents include the same as those that the chain or cyclic aliphatic hydrocarbon group in the above may have.

[0244] In the above general formula (d1-1), n １ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and even more preferably an integer of 2 to 4.

[0245] Preferred specific examples of the anion moiety in the compound (d1-1) are shown below.

[0246]

[0247] The anion moiety in compound (d1-1) is preferably an anion represented by any one of the above chemical formulas (an-d01-1) to (an-d01-6), more preferably an anion represented by any one of the above chemical formulas (an-d01-1) to (an-d01-5), and even more preferably an anion represented by any one of the above chemical formulas (an-d01-1) to (an-d01-3).

[0248] [Cation moiety] In the above general formula (d1-1), m is an integer of 1 or more, and 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), more preferably the cation represented by the general formula (ca-1), and even more preferably the cation represented by any one of the general formulae (ca-1-1) to (ca-1-70).

[0249] Among the above compounds, the compound (d1-1) is preferably a compound (d1-1-1) represented by the following general formula (d1-1-1).

[0250]

[0251] [In formula (d1-1-1), Rd １１ X represents a linear or cyclic aliphatic hydrocarbon group which may have a substituent. １ is a methylene group which may have a heteroatom or a substituent. １is an integer from 1 to 10. ２０１ ~R ２０３ R each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ２０１ ~R ２０３ may be bonded to each other to form a ring together with the sulfur atom in the formula.

[0252] In the compound (d1-1-1), the anion moiety of the compound (d1-1-1) is the same as the anion moiety of the compound (d1-1), and the cation moiety of the compound (d1-1-1) is the same as the cation represented by the above general formula (ca-1).

[0253] In the resist composition of this embodiment, one type of compound (d1-1) may be used alone, or two or more types may be used in combination. In the resist composition of this embodiment, the amount of compound (d1-1) relative to 100 parts by mass of the component (A) is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 3 to 15 parts by mass. By ensuring that the amount of compound (d1-1) is at least the above-mentioned preferable lower limit, better lithography properties are likely to be obtained. On the other hand, by ensuring that the amount is no more than the above-mentioned preferable upper limit, sensitivity can be maintained at a better level, and throughput can also be improved.

[0254] <Compound (d1-2)> The compound (d1-2) is a compound represented by the following general formula (d1-2).

[0255]

[0256] [In general formula (d1-2), Rd １２ X represents a linear or cyclic aliphatic hydrocarbon group which may have a substituent. ２ is a methylene group which may have a heteroatom or a substituent. ２ is an integer of 1 to 10. m is an integer of 1 or more, and M ｍ＋ is an m-valent organic cation.

[0257] [Anion moiety] In general formula (d1-2), Rd １２represents a chain or cyclic aliphatic hydrocarbon group which may have a substituent, and Rd １１ The substituents are the same as the optionally substituted chain or cyclic aliphatic hydrocarbon groups in the above.

[0258] In the above general formula (d1-2), X ２ is a heteroatom or a methylene group which may have a substituent, preferably a heteroatom, and more preferably an oxygen atom (—O—).

[0259] In the above general formula (d1-2), n ２ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and even more preferably an integer of 1 to 3.

[0260] Preferred specific examples of the anion moiety in the compound (d1-2) are shown below.

[0261]

[0262] [Cation moiety] In the above general formula (d1-2), m is an integer of 1 or more, and 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), more preferably the cation represented by the general formula (ca-1), and even more preferably the cation represented by any one of the general formulae (ca-1-1) to (ca-1-70).

[0263] Among the above compounds, the compound (d1-2) is preferably a compound (d1-2-1) represented by the following general formula (d1-2-1).

[0264]

[0265] [In formula (d1-2-1), Rd １２ X represents a linear or cyclic aliphatic hydrocarbon group which may have a substituent. ２ is a methylene group which may have a heteroatom or a substituent. ２ is an integer from 1 to 10. ２０１ ~R ２０３R each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ２０１ ~R ２０３ may be bonded to each other to form a ring together with the sulfur atom in the formula.

[0266] In the compound (d1-2-1), the anion moiety of the compound (d1-2-1) is the same as the anion moiety of the compound (d1-2), and the cation moiety of the compound (d1-2-1) is the same as the cation represented by the above general formula (ca-1).

[0267] In the resist composition of this embodiment, the compound (d1-2) may be used alone, or two or more types may be used in combination. In the resist composition of this embodiment, the amount of compound (d1-2) relative to 100 parts by mass of the component (A) is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 2 to 15 parts by mass. By ensuring that the amount of compound (d1-2) is at least the above-mentioned preferable lower limit, better lithography properties are likely to be obtained. On the other hand, by ensuring that the amount is no more than the above-mentioned preferable upper limit, sensitivity can be maintained at a higher level, and throughput can also be improved.

[0268] <Compound (d2-1)> The compound (d2-1) is a compound represented by the following general formula (d2-1).

[0269]

[0270] [In formula (d2-1), Rd ２ is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O); m is an integer of 1 or more; M ｍ＋ is an m-valent organic cation.

[0271] [Anion moiety] In the above general formula (d2-1), Rd ２ is a cyclic aliphatic hydrocarbon group having an oxygen atom (═O). Here, "having an oxygen atom (═O)" means that two hydrogen atoms bonded to one carbon atom constituting the cyclic aliphatic hydrocarbon group are substituted with oxygen atoms (═O).

[0272] The cyclic aliphatic hydrocarbon group is preferably a cyclic aliphatic hydrocarbon group having 4 to 20 carbon atoms. Specific examples of the cyclic aliphatic hydrocarbon group include monocyclic alicyclic groups and polycyclic alicyclic groups.

[0273] The monocyclic alicyclic group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or monocycloalkene. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The monocycloalkene is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentene and cyclohexene.

[0274] The polycyclic alicyclic group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 20 carbon atoms. Among these, the polycycloalkane is preferably adamantane, norbornane, isobornane, tricyclo[5.2.1.0] ２，６ ] Polycycloalkanes having a polycyclic skeleton of a bridged ring system such as decane and tetracyclododecane are preferred.

[0275] Rd ２ may have a substituent other than an oxygen atom (=O). Examples of the substituent include the above-mentioned Rd １１ Examples of the substituent include the same as the substituent that the linear or cyclic aliphatic hydrocarbon group in the above may have, and among these, an alkyl group is preferred.

[0276] Rd ２ Preferred specific examples of the formula are shown below: In the formulas below, * represents a bond bonded to the methylene group in the general formula (d2-1) above.

[0277]

[0278] Preferred specific examples of the anion moiety in the compound (d2-1) are shown below.

[0279]

[0280] [Cation moiety] In the above general formula (d2-1), m is an integer of 1 or more, and 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), more preferably the cation represented by the general formula (ca-1), and even more preferably the cation represented by any one of the general formulae (ca-1-1) to (ca-1-70).

[0281] Among the above compounds, the compound (d2-1) is preferably a compound (d2-1-1) represented by the following general formula (d2-1-1) (hereinafter also referred to as "compound (d2-1-1)").

[0282]

[0283] [In formula (d2-1-1), Rd ２ is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O). ２０１ ~R ２０３ R each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. ２０１ ~R ２０３ may be bonded to each other to form a ring together with the sulfur atom in the formula.

[0284] In the compound (d2-1-1), the anion moiety of the compound (d2-1-1) is the same as the anion moiety of the compound (d2-1), and the cation moiety of the compound (d2-1-1) is the same as the cation represented by the above general formula (ca-1).

[0285] In the resist composition of this embodiment, one type of compound (d2-1) may be used alone, or two or more types may be used in combination. In the resist composition of this embodiment, the amount of compound (d2-1) relative to 100 parts by mass of the component (A) is preferably 0.1 to 15 parts by mass, more preferably 1 to 12 parts by mass, and even more preferably 2 to 10 parts by mass. By ensuring that the amount of compound (d2-1) is at least as large as the above-mentioned preferable lower limit, better lithography properties are likely to be obtained. On the other hand, by ensuring that the amount is at most as large as the above-mentioned preferable upper limit, sensitivity can be maintained at a higher level, and throughput can also be improved.

[0286] In the resist composition of this embodiment, the total amount of the component (D1) and the component (D2) is preferably 1 to 40 parts by mass, more preferably 3 to 30 parts by mass, and even more preferably 5 to 25 parts by mass, per 100 parts by mass of the component (A). By ensuring that the total amount of the component (D1) and the component (D2) is at least as large as the preferred lower limit, better lithography properties are likely to be obtained. On the other hand, by ensuring that the total amount is at most the preferred upper limit, better sensitivity can be maintained and better throughput can be achieved.

[0287] In the resist composition of this embodiment, the mass ratio of the content of the component (D1) to the content of the component (D2) (component (D1):component (D2)) is preferably 1:3 to 3:1, and more preferably 1:2 to 2:1.

[0288] In the resist composition of this embodiment, from the viewpoint of improving sensitivity, it is preferable that the content of the component (D1) is greater than the content of the component (D2). On the other hand, from the viewpoint of improving roughness reduction, it is preferable that the content of the component (D2) is greater than the content of the component (D1). More specifically, from the viewpoint of improving sensitivity, it is preferable that the ratio 1 < component (D1) / component (D2) < 4, and it is more preferable that the ratio 1 < component (D1) / component (D2) < 3. On the other hand, from the viewpoint of improving roughness reduction, it is preferable that the ratio 1 < component (D2) / component (D1) < 4, and it is more preferable that the ratio 1 < component (D2) / component (D1) < 3.

[0289] <Other Components> The resist composition of this embodiment may further contain other components in addition to the above-described components (A), (B), (D1), and (D2). Examples of other components include the following components (E), (F), and (S).

[0290] <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.

[0291] 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.

[0292] 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.

[0293] <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):

[0294] 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).

[0295]

[0296] [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.

[0297] 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.

[0298] 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.

[0299] 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.

[0300] 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).

[0301] <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 alone, or as a mixed solvent of two or more different solvents. Of these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, ethyl lactate (EL), and cyclohexanone are preferred.

[0302] 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%.

[0303] 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.

[0304] A resist composition according to an embodiment of the present invention contains the aforementioned component (A), component (B), component (D1), and component (D2), as well as the optional components described above, as necessary. Suitable examples include resist compositions containing the component (A), component (B), component (D1), component (D2), component (E), component (F), and component (S).

[0305] As explained above, the resist composition according to an embodiment of the present invention contains the aforementioned component (A), component (B), component (D1), and component (D2). By including the components (B), (D1), and (D2) in the resist composition, each of which contains a compound having a specific structure, it is presumed that high sensitivity can be achieved and a resist pattern that exhibits excellent roughness reduction can be formed.

[0306] [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.

[0307] 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. Thereafter, the resist film is 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.

[0308] 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.

[0309] 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.

[0310] 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.

[0311] An example of an alkaline developer used in the development treatment in the alkaline development process is a 0.1 to 10% by mass aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent that can dissolve component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0312] Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0313] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0314] 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.

[0315] 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 discharging the developer while scanning a developer discharging nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0316] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously discharging the rinse liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dipping method), or a method of spraying the rinse liquid onto the surface of the support (spray method).

[0317] 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).

[0318] The resist pattern forming method of the present embodiment, as explained above, uses the resist composition according to the above-mentioned embodiment of the present invention, and therefore when forming a resist pattern, high sensitivity can be achieved, and a resist pattern with excellent lithography properties and a good shape can be formed.

[0319] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0320] Each polymer compound was synthesized using monomers that derive the structural units constituting the polymer compounds (A)-1 to (A)-8 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.

[0321]

[0322]

[0323] <Preparation of Resist Compositions> (Examples 1 to 21, Comparative Examples 1 to 5) The components shown in Table 1 or 2 below were mixed and dissolved in solvent S-1 to prepare the resist compositions of each example. S-1: Mixed solvent of 1,650 parts by mass of propylene glycol monomethyl ether acetate (PGMEA), 600 parts by mass of propylene glycol monomethyl ether (PGME), and 750 parts by mass of cyclohexanone The blending ratio of PGMEA, PGME, and cyclohexanone in S-1 (PGMEA:PGME:cyclohexanone) was 55:20:25.

[0324]

[0325]

[0326] In Tables 1 and 2, the abbreviations have the following meanings. The values ​​in brackets [ ] indicate the blend amounts (parts by mass). (A)-1 to (A)-8: the polymer compounds (A)-1 to (A)-8 described above. (B1)-1 to (B1)-5: acid generators comprising compounds represented by the following chemical formulas (B1)-1 to (B1)-5. (B2)-1: acid generators comprising compounds represented by the following chemical formula (B2)-1. (D1)-1 to (D1)-8: acid diffusion controllers comprising compounds represented by the following chemical formulas (D1)-1 to (D1)-8. (D2)-1 to (D2)-3: acid diffusion controllers comprising compounds represented by the following chemical formulas (D2)-1 to (D2)-3. (D3)-1 to (D3)-2: acid diffusion controllers comprising compounds represented by the following chemical formulas (D3)-1 to (D3)-2. (E)-1: A compound represented by the following chemical formula (E)-1. (F)-1: A hydrophobic resin (F)-1 containing the following structural unit (composition ratio (molar ratio): l / m=80 / 20, Mw: 20,000, Mw / Mn: 1.70).

[0327]

[0328]

[0329]

[0330]

[0331]

[0332]

[0333] <Formation of Resist Pattern> An organic antireflective coating composition "ARC29" (manufactured by Brewer Science) was applied to 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 98 nm. A resist composition was applied to the organic antireflective coating using a spinner, and then prebaked (PAB) on a hot plate at 100°C for 60 seconds and dried, thereby forming a resist film with a thickness of 100 nm.

[0334] The wafer was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (6% halftone) using an XT-1900Gi ArF immersion exposure system (manufactured by ASML; NA (numerical aperture) = 1.35, dipole (in / out = 0.78 / 0.97) with TE polarization, immersion medium: water). Then, a PEB treatment was performed at 90°C for 60 seconds.

[0335] Next, alkaline development was performed for 10 seconds using a 2.38% by mass aqueous solution of TMAH (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C, followed by rinsing with pure water for 30 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 45 nm and a pitch of 90 nm was formed.

[0336] [Evaluation of Optimal Exposure Amount (Eop)] The line size in the above <Formation of Resist Pattern> was observed, and the exposure amount required to form an LS pattern with a line width of 45 nm and a pitch of 90 nm was determined as the optimal exposure amount (Eop) (mJ / cm ２ ) are shown in Tables 1 and 2.

[0337] [Evaluation of LWR (Line Width Roughness)] For the LS patterns formed in the above <Formation of Resist Pattern>, 3σ, a measure of LWR, was determined and is shown in Tables 1 and 2. "3σ" represents three times the standard deviation (σ) (unit: nm) obtained from the measurement results of 400 line positions measured in the longitudinal direction of the line using a scanning electron microscope (accelerating voltage 800 V, product name: CG-6300, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the smaller the roughness of the line sidewalls, meaning that an LS pattern with a more uniform width was obtained.

[0338] The results shown in Tables 1 and 2 confirm that the resist compositions of the examples exhibited better roughness reduction properties than the resist compositions of the comparative examples, and that it was possible to achieve both high sensitivity and roughness reduction properties.

[0339] The resist composition of Comparative Example 1 used the compound (B2)-1 which does not have a specific structure instead of the component (B) which has a specific structure as an acid generator, and therefore was inferior in sensitivity and roughness reduction properties compared to the resist compositions of Examples. The resist composition of Comparative Example 2 used only the component (D2) which has a specific structure as an acid diffusion controller, and did not use the component (D1) which has a specific structure, and therefore was inferior in sensitivity and roughness reduction properties compared to the resist compositions of Examples.

[0340] The resist composition of Comparative Example 3 used only the component (D1) having a specific structure as an acid diffusion controller, and did not use the component (D2) having a specific structure, and therefore exhibited inferior roughness reduction properties compared to the resist compositions of Examples, and was unable to achieve both high sensitivity and roughness reduction. The resist compositions of Comparative Examples 4 and 5 used compounds (D3)-1 and (D3)-2, which do not have a specific structure, instead of the component (D2) having a specific structure as an acid diffusion controller, and therefore were inferior in sensitivity and roughness reduction properties compared to the resist compositions of Examples.

[0341] According to the present invention, it is possible to provide a resist composition that is capable of forming a resist pattern that achieves high sensitivity and exhibits excellent roughness reduction, and a method of forming a resist pattern that uses the resist composition.

[0342] 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. 2023-206088) filed on December 6, 2023, the contents of which are incorporated herein by reference.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; an acid generator component (B) that generates an acid upon exposure; a first acid diffusion control component (D1); and a second acid diffusion control component (D2); the acid generator component (B) comprises a compound represented by the following general formula (b1-1); the first acid diffusion control component (D1) comprises a compound represented by the following general formula (d1-1) or (d1-2); and the second acid diffusion control component (D2) comprises a compound represented by the following general formula (d2-1). [In general formula (b1-1), R １ ~R ３ are each independently an at least partially fluorinated alkyl or cycloalkyl group, or R １ ~R ３ At least two of the groups may be bonded to each other to form a fluorinated alkylene group. m is an integer of 1 or more, M ｍ＋ is an m-valent organic cation. [In general formula (d1-1) and general formula (d1-2), Rd １１ and Rd １２ X represents a linear or cyclic aliphatic hydrocarbon group which may have a substituent. １ and X ２ Each of n independently represents a heteroatom or a methylene group which may have a substituent. １ and n ２ Each m is independently an integer of 1 to 10. Each m is independently an integer of 1 or more, M ｍ＋ are each independently an m-valent organic cation. [In formula (d2-1), Rd ２ is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O); m is an integer of 1 or more, M ｍ＋ is an organic cation having a valence of m.

2. M in the general formula (b1-1) ｍ＋ The resist composition according to claim 1, wherein is a cation represented by the following general formula (b-2): [In general formula (b-2), Rb ２０１ ~Rb ２０３ Rb each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. ２０１ ~Rb ２０３ may be bonded to each other to form a ring together with the sulfur atom in general formula (b-2).

3. The resist composition according to claim 1 or 2, wherein the base component (A) contains a polymeric compound (A1) having a structural unit (a1) represented by the following general formula (a-1): [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.

4. The resist composition according to claim 3, wherein the polymer compound (A1) further contains a structural unit (a2) represented by the following general formula (a-2): [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.

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

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