Resist Composition and Resist Pattern Forming Method

Abstract

The present invention relates to 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 contains a polymer compound (A1) having a structural unit (a0) represented by the general formula (a0-1), a compound (B1) represented by the general formula (b1), and a compound (D1) represented by the general formula (d1). R is a hydrogen atom or the like; Va 01 is a divalent linking group; n a01 is an integer of 1 to 2; Ra 01 is a lactone ring-containing group having a cyano group or the like; Yb 01 is a divalent linking group or a single bond; Lb 01 is -C(=O)-O- or the like; Rb 01 to Rb 03 is an alkyl group; Rb 04 to Rb 06 is an alkyl group or the like; n b04 is an integer of 0 to 4; n b05 to n b06 is an integer of 0 to 5; X ‑ is a counter anion; Rd 01 is a cyclic group or the like; M m+ is an m-valent organic cation. [Chemical formula 1]

Description

Technical Field

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

[0002] This application claims priority based on Japanese Patent Application No. 2019-219010 filed in Japan on December 3, 2019, and incorporates its content herein. Background Art

[0003] In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, due to the progress of lithography technology, the miniaturization of patterns has rapidly advanced. As a miniaturization method, generally, the wavelength of the exposure light source is shortened (the energy is increased).

[0004] For resist materials, lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing fine-sized patterns are required.

[0005] As a resist material that meets such requirements, a chemically amplified resist composition containing a base material component whose solubility in a developer changes due to the action of an acid and an acid generator component that generates an acid upon exposure has been conventionally used.

[0006] Generally, in order to improve lithography characteristics and the like, a resin having a plurality of structural units is used in a chemically amplified resist composition.

[0007] For example, Patent Document 1 describes a resist composition and the like in which a polymer compound having two specific structural units is used to improve lithography characteristics.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-124548 Summary of the Invention

[0011] Technical Problem to be Solved by the Invention

[0012] Recently, further progress in lithography technology, expansion of application fields, etc. have been continuously promoted, and the miniaturization of patterns has rapidly advanced. And, along with this, in manufacturing semiconductor elements and the like, a technology capable of forming a fine pattern having a pattern width size of less than 100 nm in a good shape is required.

[0013] However, in the conventional resist composition described in the above Patent Document 1, it is difficult to balance high sensitivity and lithography characteristics such as defects.

[0014] The present invention has been completed in view of the above circumstances, and its technical problem is to provide a resist composition that achieves high sensitivity and excellent lithography characteristics such as defects, and a resist pattern forming method using the resist composition.

[0015] Solution for solving the above technical problem

[0016] In order to solve the above technical problem, the present invention adopts the following constitution.

[0017] That is, the first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid. It is characterized by containing: a base material component (A) whose solubility in a developer changes due to the action of an acid; an acid generator component (B) that generates an acid upon exposure; and an acid diffusion control agent component (D). The base material component (A) includes a polymer compound (A1) having a structural unit (a0) represented by the following general formula (a0-1), the acid generator component (B) includes a compound (B1) represented by the following general formula (b1), and the acid diffusion control agent component (D) includes a compound (D1) represented by the following general formula (d1).

[0018] [Chemical formula 1]

[0019]

[0020] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 01 represents a divalent linking group. n a01 is an integer from 1 to 2. Ra 01 represents a lactone ring-containing group having at least one substituent selected from the group consisting of a halogen atom, a carboxyl group, an acyl group, a nitro group, and a cyano group.]

[0021] [Chemical formula 2]

[0022]

[0023] [In the formula, Yb 01 represents a divalent linking group or a single bond. Lb 01 represents -C(=O)-O-, -O-C(=O)-, -O-, or -O-C(=O)-Lb 011 -, Lb 011 represents an alkylene group having 1 to 3 carbon atoms. Rb 01 ~Rb 03 each independently represents an alkyl group, and two or more of Rb 01 ~Rb 03 can be bonded to each other to form a ring structure. Rb 04 ~Rb 06Each independently represents an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group or a nitro group. n b04 represents an integer of 0 to 4, n b05 ~n b06 each independently represents an integer of 0 to 5. X - represents a counter anion. ]

[0024] [Chemical Formula 3]

[0025]

[0026] [In the formula, Rd 01 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. Among them, a fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in the formula. m is an integer of 1 or more, and M m+ each independently is an m-valent organic cation. ]

[0027] The second aspect of the present invention is a method for forming a resist pattern, comprising: a step of forming a resist film on a support using the resist composition of the first aspect; a step of exposing the resist film; and a step of developing the exposed resist film to form a resist pattern.

[0028] Advantages of the Invention

[0029] According to the present invention, it is possible to provide a resist composition which realizes high sensitivity and has excellent lithography characteristics such as defects, and a method for forming a resist pattern using the resist composition. Detailed Embodiments

[0030] In the present specification and the present claims, "aliphatic" is a relative concept with respect to aromatic, and is defined as representing a group, a compound, etc. that do not have aromaticity.

[0031] Unless otherwise specified, "alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.

[0032] Unless otherwise specified, "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups.

[0033] Examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0034] The "structural unit" refers to a monomer unit (monomeric unit) constituting a high molecular compound (resin, polymer, copolymer).

[0035] In the case where "may have a substituent" is described, it includes two cases: the case where a hydrogen atom (-H) is substituted with a monovalent group and the case where a methylene group (-CH2-) is substituted with a divalent group.

[0036] "Exposure" refers to a concept that includes irradiation with all radiations.

[0037] "Acid-decomposable group" is an acid-decomposable group having at least a part of the bonds in the structure of the acid-decomposable group cleavable by the action of an acid.

[0038] As an acid-decomposable group whose polarity increases by the action of an acid, for example, a group that decomposes by the action of an acid to generate a polar group can be exemplified.

[0039] As a polar group, for example, a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group (-SO3H), etc. can be exemplified.

[0040] More specifically, as an acid-decomposable group, a group obtained by protecting the polar group with an acid-dissociable group (for example, a group obtained by protecting the hydrogen atom of a polar group containing OH with an acid-dissociable group) can be exemplified.

[0041] "Acid-dissociable group" refers to the following two: (i) an acid-dissociable group having a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group cleavable by the action of an acid; or (ii) a group in which, after a part of the bonds are cleaved by the action of an acid, a decarboxylation reaction further occurs, whereby the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved.

[0042] It is required that the acid-dissociable group constituting the acid-decomposable group is a group having a lower polarity than the polar group generated by the dissociation of the acid-dissociable group. Thus, when the acid-dissociable group is dissociated by the action of an acid, a polar group having a higher polarity than the acid-dissociable group is generated and the polarity increases. As a result, the polarity of the whole of the (A1) component increases. Due to the increase in polarity, the solubility in the developer changes relatively. In the case where the developer is an alkaline developer, the solubility increases, and in the case where the developer is an organic developer, the solubility decreases.

[0043] "Base material component" refers to an organic compound having film-forming ability. The organic compounds used as base material components are roughly classified into non-polymers and polymers. As non-polymers, non-polymers having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, when referring to a "low molecular weight compound", it means a non-polymer having a molecular weight of 500 or more and less than 4000. As polymers, polymers having a molecular weight of 1000 or more are usually used. Hereinafter, when referring to a "resin", "high molecular weight compound" or "polymer", it means a polymer having a molecular weight of 1000 or more. As the molecular weight of the polymer, the weight average molecular weight in terms of polystyrene determined by GPC (gel permeation chromatography) is used.

[0044] "Derived structural unit" means a structural unit formed by cleavage of a multiple bond between carbon atoms, such as an ethylenic double bond.

[0045] The hydrogen atom bonded to the carbon atom at the α-position of "acrylate" may be substituted by a substituent. The substituent (R αx ) substituting the hydrogen atom bonded to the carbon atom at the α-position is an atom or group other than a hydrogen atom. In addition, it also includes itaconic acid diesters in which the substituent (R αx ) is substituted by a substituent containing an ester bond, and α-hydroxyacrylates in which the substituent (R αx ) is substituted by a hydroxyalkyl group or a group modifying its hydroxyl group. In addition, unless otherwise specified, the carbon atom at the α-position of acrylate means the carbon atom to which the carbonyl group of acrylic acid is bonded.

[0046] Hereinafter, acrylate in which the hydrogen atom bonded to the carbon atom at the α-position is substituted by a substituent is sometimes referred to as α-substituted acrylate.

[0047] "Derivative" means a concept including compounds in which the hydrogen atom at the α-position of the target compound is substituted by other substituents such as an alkyl group or a haloalkyl group, and their derivatives. As their derivatives, compounds obtained by substituting the hydrogen atom of the hydroxyl group of the target compound whose α-position hydrogen atom can be substituted by a substituent with an organic group; compounds obtained by bonding a substituent other than a hydroxyl group to the target compound whose α-position hydrogen atom can be substituted by a substituent, etc. can be exemplified. In addition, unless otherwise specified, the α-position means the first carbon atom adjacent to the functional group.

[0048] As the substituent substituting the hydrogen atom at the α-position of substituted hydroxystyrene, the same group as R αx can be exemplified.

[0049] In this specification and the claims, depending on the structure represented by the chemical formula, there are structures with asymmetric carbons, and structures of enantiomers or diastereomers may exist. In such cases, these isomers are representatively represented by one chemical formula. These isomers can be used alone or as a mixture.

[0050] (Resist composition)

[0051] The resist composition of this embodiment is a resist composition that generates an acid upon exposure and whose solubility in the developer changes due to the action of the acid.

[0052] The above-mentioned resist composition contains a substrate component (A) (hereinafter also referred to as the “(A) component”) whose solubility in the developer changes due to the action of the acid, an acid generator component (B) (hereinafter also referred to as the “(B) component”) that generates an acid upon exposure, and an acid diffusion control agent component (D). The substrate component (A) includes a polymer compound (A1) having a structural unit (a0) represented by the general formula (a0-1). The acid generator component (B) includes a compound (B1) represented by the general formula (b1). The acid diffusion control agent component (D) includes a compound (D1) represented by the general formula (d1).

[0053] If a resist film is formed using the resist composition of this embodiment and the resist film is selectively exposed, an acid is generated from the (B) component in the exposed portion of the resist film, and the solubility of the (A) component in the developer changes due to the action of the acid. On the other hand, in the unexposed portion of the resist film, the solubility of the (A) component in the developer does not change. Therefore, a difference in solubility in the developer is generated between the exposed portion and the unexposed portion. Therefore, if the resist film is developed, in the case where the resist composition is positive, the exposed portion of the resist film is dissolved and removed, thereby forming a positive resist pattern. In the case where the resist composition is negative, the unexposed portion of the resist film is dissolved and removed, thereby forming a negative resist pattern.

[0054] In this specification, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive resist pattern is called a positive resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative resist pattern is called a negative resist composition. The resist composition of this embodiment can be a positive resist composition or a negative resist composition. In addition, the resist composition of this embodiment can be used in an alkaline development process using an alkaline developer in the development treatment when forming a resist pattern, or can also be used in a solvent development process using a developer containing an organic solvent (organic developer) in the development treatment.

[0055] <(A) component>

[0056] In the resist composition of the present embodiment, the (A) component contains a high molecular compound (A1) (hereinafter also referred to as the "(A1) component") whose solubility in a developer changes due to the action of an acid. By using the (A1) component, since the polarity of the substrate component changes before and after exposure, good development contrast can be obtained not only in the alkaline development process but also in the solvent development process.

[0057] As the (A) component, at least the (A1) component is used, and other high molecular compounds and / or low molecular compounds may be used in combination with the (A1) component.

[0058] In the case of applying the alkaline development process, the substrate component containing the (A1) component is hardly soluble in the alkaline developer before exposure. For example, if an acid is generated from the (B) component by exposure, its polarity increases due to the action of the acid, and its solubility in the alkaline developer increases. Therefore, in the formation of a resist pattern, if the resist film obtained by coating the resist composition on a support is selectively exposed, the solubility of the exposed portion of the resist film in the alkaline developer changes from hardly soluble to soluble. On the other hand, since the unexposed portion of the resist film remains alkali-insoluble and does not change, a positive resist pattern can be formed by performing alkaline development.

[0059] On the other hand, in the case of applying the solvent development process, the substrate component containing the (A1) component has high solubility in the organic developer before exposure. For example, if an acid is generated from the (B) component by exposure, its polarity becomes higher due to the action of the acid, and its solubility in the organic developer decreases. Therefore, in the formation of a resist pattern, if the resist film obtained by coating the resist composition on a support is selectively exposed, the solubility of the exposed portion of the resist film in the organic developer changes from soluble to hardly soluble. On the other hand, since the unexposed portion of the resist film remains soluble and does not change, by developing with an organic developer, a contrast can be generated between the exposed portion and the unexposed portion, and a negative resist pattern can be formed.

[0060] In the resist composition of the present embodiment, one type of the (A) component may be used alone, or two or more types may be used in combination.

[0061] ·Regarding the (A1) component

[0062] The (A1) component is a resin component whose solubility in a developer changes due to the action of an acid.

[0063] The (A1) component has a structural unit (a0) represented by the following general formula (a0-1).

[0064] (Component (A1)) may, in addition to the structural unit (a0), have other structural units as needed.

[0065] 《Structural unit (a0)》

[0066] The structural unit (a0) is a structural unit represented by the following general formula (a0-1).

[0067] [Chemical formula 4]

[0068]

[0069] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 01 represents a divalent linking group. n a01 is an integer from 1 to 2. Ra 01 represents a lactone ring-containing group having at least one substituent selected from the group consisting of a halogen atom, a carboxyl group, an acyl group, a nitro group, and a cyano group.]

[0070] In the formula (a0-1), 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. The alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are replaced by halogen atoms. As the halogen atom, a fluorine atom is particularly preferred.

[0071] As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluoroalkyl group having 1 to 5 carbon atoms is preferred, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferred.

[0072] In the formula (a0-1), Va 01 is a divalent linking group. As the divalent linking group, there is no particular limitation, and examples include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, etc.

[0073] · Divalent hydrocarbon group which may have a substituent:

[0074] When Va 01 is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0075] ·· The aliphatic hydrocarbon group in Va 01

[0076] An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0077] Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0078] ···linear or branched aliphatic hydrocarbon group

[0079] The number of carbon atoms of the linear aliphatic hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, still more preferably 1 to 4, and most preferably 1 to 3.

[0080] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include methylene [-CH2-], ethylene [-(CH2)2-], propylene [-(CH2)3-], butylene [-(CH2)4-], pentylene [-(CH2)5-], etc.

[0081] The number of carbon atoms of the branched aliphatic hydrocarbon group is preferably 2 to 10, more preferably 3 to 6, still more preferably 3 or 4, and most preferably 3.

[0082] As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylenes such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylenes such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkylpropylenes such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkylbutylenes such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, etc. As the alkyl in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0083] The linear or branched aliphatic hydrocarbon group may have a substituent or may not have a substituent. Examples of the substituent include a fluorine atom, a fluoroalkyl group having 1 to 5 carbon atoms substituted by a fluorine atom, a carbonyl group, etc.

[0084] ···aliphatic hydrocarbon group containing a ring in its structure

[0085] Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group which may have a substituent and contains a heteroatom in the ring structure (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group obtained by terminal-bonding the cyclic aliphatic hydrocarbon group to a linear or branched aliphatic hydrocarbon group, a group in which the cyclic aliphatic hydrocarbon group is interposed between linear or branched aliphatic hydrocarbon groups, and the like. Examples of the linear or branched aliphatic hydrocarbon group are the same as the above-mentioned aliphatic hydrocarbon groups.

[0086] The number of carbon atoms of the cyclic aliphatic hydrocarbon group is preferably 3 to 20, more preferably 3 to 12.

[0087] The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred, and specifically, cyclopentane, cyclohexane, etc. can be exemplified. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferred, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. can be exemplified.

[0088] 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 haloalkyl group, a hydroxyl group, a carbonyl group, etc.

[0089] The alkyl group as the substituent preferably has 1 to 5 carbon atoms, more preferably methyl, ethyl, propyl, n-butyl, or tert-butyl.

[0090] The alkoxy group as the substituent preferably has 1 to 5 carbon atoms, more preferably methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, or tert-butoxy, and further preferably methoxy or ethoxy.

[0091] The halogen atom as the substituent is preferably a fluorine atom.

[0092] Examples of the haloalkyl group as the substituent include a group in which some or all of the hydrogen atoms of the alkyl group are replaced by the halogen atom.

[0093] In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting its ring structure may also be replaced by a heteroatom-containing substituent. Examples of the heteroatom-containing substituent are preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O-.

[0094] ··Va 01 The aromatic hydrocarbon group in

[0095] The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

[0096] If the aromatic ring is a cyclic conjugated system having 4n + 2 π electrons, there is no particular limitation, and it may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Herein, the number of carbon atoms does not include the number of carbon atoms in the substituent.

[0097] Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles obtained by substituting a part of the carbon atoms constituting the aromatic hydrocarbon ring with heteroatoms, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring, a thiophene ring, etc.

[0098] Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene or heteroarylene); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group obtained by substituting one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl or heteroaryl) with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in arylalkyls such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The number of carbon atoms of the alkylene group bonded to the aryl or heteroaryl is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0099] In the aromatic hydrocarbon group, the hydrogen atoms possessed by the aromatic hydrocarbon group may also be substituted by substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted by substituents. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, etc.

[0100] The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, more preferably methyl, ethyl, propyl, n-butyl, or tert-butyl.

[0101] Examples of the alkoxy group, halogen atom, and haloalkyl group as the substituent include the groups exemplified as the substituents for substituting the hydrogen atoms possessed by the cyclic aliphatic hydrocarbon group.

[0102] · A divalent linking group containing a heteroatom:

[0103] In Va 01In the case of a divalent linking group containing a heteroatom, preferred groups as the linking group include -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)-(H may be substituted by substituents such as an alkyl group, an acyl group, etc.), -S-, -S(=O)2-, -S(=O)2-O-, and a group represented by the general formula -Y 21 -O-Y 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 -[wherein, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer of 0 to 3].

[0104] When the divalent linking group containing a heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)-, the H thereof may be substituted by substituents such as an alkyl group, an acyl group, etc. The carbon number of the substituent (alkyl group, acyl group, etc.) is preferably 1 to 10, more preferably 1 to 8, and particularly preferably 1 to 5.

[0105] In the general formula -Y 21 -O-Y 22 -,-Y 21 -O-,-Y 21 -C(=O)-O-,-C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 -, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. As the divalent hydrocarbon group, the same groups as those of the divalent hydrocarbon group which may have a substituent can be exemplified.

[0106] As Y 21, preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group.

[0107] As Y 22 , preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group preferably has 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

[0108] In the formula -[Y 21 -C(=O)-O] m” -Y 22 -, m'' is an integer from 0 to 3, preferably an integer from 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is to say, as the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 -, the group represented by the formula -Y 21 -C(=O)-O-Y 22 - is particularly preferred. Among them, the group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’ - is preferred. In this formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0109] Among them, as Va 01 , preferably a divalent hydrocarbon group which may have a substituent, more preferably an aliphatic hydrocarbon group which may have a substituent, still more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may have a substituent. The alkylene group is more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As Va 01 , particularly preferably a methylene group or an ethylene group.

[0110] In the formula (a0-1), n a01 is an integer from 1 to 2. n a01 is preferably 1.

[0111] In the formula (a0-1), Ra 01It is a lactone ring-containing group having at least one substituent selected from the group consisting of a halogen atom, a carboxyl group, an acyl group, a nitro group, and a cyano group. The "lactone ring-containing group" means a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. The lactone ring is denoted as the first ring. In the case of only the lactone ring, it is called a monocyclic group, and in the case of also having other ring structures, it is called a polycyclic group regardless of its structure. The lactone ring-containing group can be a monocyclic group or a polycyclic group.

[0112] As Ra 01 The lactone ring-containing group in is not particularly limited, and any lactone ring-containing group can be used. As the lactone ring-containing group, for example, the groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be cited. As Ra 01 The lactone ring-containing group in can be exemplified by the groups represented by the following general formulas (a2-r-1) to (a2-r-7), where Ra' 21 Is a group of a halogen atom, a carboxyl group, an acyl group, a nitro group or a cyano group.

[0113] As Ra 01 A preferred example of the lactone ring-containing group in can be exemplified by the lactone ring-containing group represented by the following general formula (Ra0-1).

[0114] [Chemical formula 5]

[0115]

[0116] [In the formula, Ra 012 And Ra 013 Each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkylthio group having 1 to 5 carbon atoms, or Ra 012 And Ra 013 Are bonded to each other to represent an alkylene group having 1 to 6 carbon atoms that may contain an oxygen atom or a sulfur atom, an ether bond (-O-), or a thioether bond (-S-). X 011 Represents a halogen atom, a carboxyl group, an acyl group, a nitro group, or a cyano group. Ra 011 Represents an alkyl group having 1 to 6 carbon atoms that may contain a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxy part may be protected by a protecting group and may contain a halogen atom, a carboxyl group capable of forming a salt, or a substituted oxycarbonyl group. p 01 Represents an integer from 0 to 8, and q 01 Represents an integer from 1 to 9. Among them, p 01 +q 01 ≤9. In the case where there are two or more X 011 , the multiple X 011 Can be the same or different from each other. In the case where there are two or more Ra 011 , the multiple Ra011 may be the same as or different from each other. In Ra 012 and Ra 013 are bonded to each other to form an alkylene group having 1 to 6 carbon atoms which may contain an oxygen atom or a sulfur atom, X 011 and Ra 011 may each independently exist as a substituent for a hydrogen atom substituting the alkylene group having 1 to 6 carbon atoms. * represents a chemical bond bonded to the oxygen atom in the formula (a0-1).]

[0117] In the formula (Ra0-1), Ra 012 and Ra 013 each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkylthio group having 1 to 5 carbon atoms, or Ra 012 and Ra 013 are bonded to each other to represent an alkylene group having 1 to 6 carbon atoms which may contain an oxygen atom or a sulfur atom, an ether bond, or a thioether bond (-S-).

[0118] The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group. Specifically, examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, and the like.

[0119] The alkoxy group having 1 to 5 carbon atoms is preferably a linear or branched alkoxy group. Specifically, examples include the groups obtained by connecting an oxygen atom (-O-) to the alkyl groups exemplified as Ra 012 and Ra 013 above.

[0120] The alkylthio group having 1 to 5 carbon atoms preferably has 1 to 4 carbon atoms. Specifically, examples include methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, tert-butylthio, and the like.

[0121] As the alkylene group having 1 to 6 carbon atoms formed by Ra 012 and Ra 013 bonded to each other, a linear or branched alkylene group is preferred. Examples include methylene, ethylene, n-propylene, isopropylene, and the like. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups having -O- or -S- interposed at the terminal or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, -CH2-S-CH2-, and the like. As the group formed by Ra 012 and Ra 013 bonded to each other, an alkylene group having 1 to 6 carbon atoms or -O- is preferred, an alkylene group having 1 to 6 carbon atoms is more preferred, an alkylene group having 1 to 5 carbon atoms is further preferred, and methylene is most preferred.

[0122] Among them, Ra 012 and Ra 013 is preferably Ra 012 and Ra 013 are bonded to each other to form an alkylene group having 1 to 6 carbon atoms. The alkylene group having 1 to 6 carbon atoms is more preferably an alkylene group having 1 to 3 carbon atoms, and further preferably a methylene group.

[0123] In the general formula (Ra0-1), Ra 011 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxy part may be protected by a protecting group and which may have a halogen atom, a carboxyl group forming a salt, or a substituted oxycarbonyl group.

[0124] Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl and the like. Among them, an alkyl group having 1 to 5 carbon atoms is preferred, an alkyl group having 1 to 4 carbon atoms is more preferred, an alkyl group having 1 to 3 carbon atoms is further preferred, methyl or ethyl is particularly preferred, and methyl is most preferred.

[0125] The alkyl group having 1 to 6 carbon atoms may or may not have a halogen atom. As the halogen atom, a fluorine atom or a chlorine atom is preferred, and a fluorine atom is more preferred. Examples of the alkyl group having 1 to 6 carbon atoms having a halogen atom include chloroalkyl groups such as chloromethyl; fluoroalkyl groups such as trifluoromethyl, 2,2,2-trifluoroethyl, pentafluoroethyl (preferably a fluoroalkyl group having 1 to 3 carbon atoms), etc.

[0126] Examples of the hydroxyalkyl group having 1 to 6 carbon atoms include hydroxymethyl, 2-hydroxyethyl, 1-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 6-hydroxyhexyl and the like.

[0127] The hydroxyalkyl group having 1 to 6 carbon atoms may or may not have a halogen atom. As the halogen atom, a fluorine atom is preferred. Examples of the hydroxyalkyl group having 1 to 6 carbon atoms having a halogen atom include difluorohydroxymethyl, 1,1-difluoro-2-hydroxyethyl, 2,2-difluoro-2-hydroxyethyl, 1,1,2,2-tetrafluoro-2-hydroxyethyl and the like.

[0128] The hydroxyalkyl group having 1 to 6 carbon atoms which may have a halogen atom preferably has 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms, and further preferably 1 carbon atom.

[0129] The hydroxyl group of the hydroxyalkyl group having 1 to 6 carbon atoms may or may not be protected by a protecting group. Examples of the protecting group for protecting the hydroxyl group include groups that can form an ether bond or an acetal bond together with the oxygen atom constituting the hydroxyl group, such as methyl and methoxymethyl; groups that can form an ester bond together with the oxygen atom constituting the hydroxyl group, such as acetyl and benzoyl, etc.

[0130] The carboxyl group capable of forming a salt is selected from the group consisting of a carboxyl group and a carboxyl group forming a salt (salt of a carboxyl group). Examples of the carboxyl group forming a salt (salt of a carboxyl group) include alkali metal salts of a carboxyl group, alkaline earth metal salts of a carboxyl group, and transition metal salts of a carboxyl group, etc.

[0131] Examples of the substituted oxycarbonyl group include alkoxycarbonyl groups obtained by bonding an alkoxy group having 1 to 4 carbon atoms to a carbonyl group (specifically, alkyl oxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, isopropoxycarbonyl, and n-propoxycarbonyl; alkenyloxycarbonyl groups such as vinyloxycarbonyl and allyloxycarbonyl); cycloalkyloxycarbonyl groups such as cyclohexyloxycarbonyl, and aryloxycarbonyl groups such as phenyloxycarbonyl, etc.

[0132] In the general formula (Ra0-1), X 011 represents a halogen atom, a carboxyl group, an acyl group, a nitro group or a cyano group. As the halogen atom, a fluorine atom is preferred. As the acyl group, an acyl group having 1 to 3 carbon atoms is preferred, and as specific examples, formyl, acetyl and propionyl can be cited. Among them, X 011 is preferably a cyano group.

[0133] In the general formula (Ra0-1), p 01 is an integer from 0 to 8. In the general formula (Ra0-1), q 01 is an integer from 1 to 9. Among them, p 01 +q 01 ≤9.

[0134] p 01 is preferably an integer from 0 to 6, more preferably an integer from 0 to 3, still more preferably 0 or 1, and particularly preferably 0.

[0135] q 01 is preferably an integer from 1 to 5, more preferably 1 or 2, and still more preferably 1.

[0136] When p 01 is an integer from 2 to 8 and there are two or more Ra 011 , the plurality of Ra 011 can be the same as or different from each other.

[0137] When q 01 is an integer from 2 to 9 and there are two or more X 011 , the plurality of X011 They may be the same as or different from each other.

[0138] In Ra 012 and Ra 013 are bonded to each other to form an alkylene group having 1 to 6 carbon atoms which may contain an oxygen atom or a sulfur atom, X 011 and Ra 011 may each independently exist as a substituent of a hydrogen atom substituting the alkylene group having 1 to 6 carbon atoms.

[0139] The structural unit (a0) is preferably a structural unit represented by the following general formula (a0-1-1).

[0140] [Chemical formula 6]

[0141]

[0142] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 01 is a divalent hydrocarbon group which may have a substituent. n a01 is an integer of 1 to 2. X 011 represents a halogen atom, a carboxyl group, an acyl group, a nitro group, or a cyano group. q 011 is an integer of 1 to 7.]

[0143] R, Va 01 and n a01 in the formula (a0-1-1) are the same as R, Va 01 and n a01 in the formula (a0-1). X 011 in the formula (a0-1-1) is the same as X 011 in the formula (Ra0-1).

[0144] q 011 in the above formula (a0-1-1) is an integer of 1 to 7, preferably 1 or 2, more preferably 1.

[0145] Specific examples of the structural unit (a0) are shown below.

[0146] In the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group. n α01 represents 1 or 2, preferably 1. Ac represents an acetyl group. X represents a halogen atom, a carboxyl group, an acyl group, a nitro group, or a cyano group, preferably a cyano group (-CN).

[0147] [Chemical formula 7]

[0148]

[0149] [Chemical formula 8]

[0150]

[0151] [Chemical Formula 9]

[0152]

[0153] Among the above, the structural unit (a0) is preferably a structural unit represented by any one of the formulas (a0-1-1-1) to (a0-1-1-18), more preferably a structural unit represented by the formula (a0-1-1-1).

[0154] The structural unit (a0) possessed by the component (A1) may be one kind or two or more kinds.

[0155] The proportion of the structural unit (a0) in the component (A1) is preferably 10 mol% or more and 80 mol% or less, more preferably 20 mol% or more and 70 mol% or less, further preferably 30 mol% or more and 60 mol% or less, still more preferably 35 mol% or more and 50 mol% or less, and particularly preferably 40 mol% or more and 50 mol% or less, relative to the total (100 mol%) of all the structural units constituting the component (A1).

[0156] By setting the proportion of the structural unit (a0) to be not less than the lower limit value of the above preferred range, the generation of defects can be more effectively suppressed. In addition, if the proportion of the structural unit (a0) is not more than the upper limit value of the above preferred range, a balance with other structural units can be achieved.

[0157] 《Other Structural Units》

[0158] In addition to the structural unit (a0), the component (A1) may have other structural units as needed.

[0159] Examples of other structural units include a structural unit (a1) containing an acid-decomposable group whose polarity increases due to the action of an acid; a structural unit (a2) containing a lactone ring-containing group, a -SO2-ring-containing group, or a carbonate ring-containing group (excluding the structural units belonging to the structural unit (a0)); a structural unit (a3) containing an aliphatic hydrocarbon group having a polar group; a structural unit (a4) containing an acid-non-dissociable aliphatic cyclic group; a structural unit (a10) represented by the following general formula (a10); a structural unit (st) derived from styrene or a styrene derivative, etc.

[0160] Regarding the structural unit (a1):

[0161] The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases due to the action of an acid.

[0162] As the acid dissociable group, groups that have been proposed as the acid dissociable group of the base resin for chemically amplified resist compositions can be exemplified.

[0163] Groups that have been proposed as the acid dissociable group of the base resin for chemically amplified resist compositions. Specifically, the "acetal type acid dissociable group", "tertiary alkyl ester type acid dissociable group", and "tertiary alkoxycarbonyl acid dissociable group" described below can be exemplified.

[0164] Acetal type acid dissociable group:

[0165] As the acid dissociable group for protecting the carboxyl group or hydroxyl group in the polar group, for example, the acid dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as "acetal type acid dissociable group") can be exemplified.

[0166] [Chemical formula 10]

[0167]

[0168] [In the formula, Ra’ 1 and Ra’ 2 are a hydrogen atom or an alkyl group. Ra’ 3 is a hydrocarbon group, and Ra’ 3 may bond to any one of Ra’ 1 and Ra’ 2 to form a ring.]

[0169] In formula (a1-r-1), preferably at least one of Ra’ 1 and Ra’ 2 is a hydrogen atom, and more preferably both are hydrogen atoms.

[0170] When Ra’ 1 or Ra’ 2 is an alkyl group, as the alkyl group, the same alkyl groups as those exemplified as the substituents that can bond to the carbon atom at the α-position in the above description of α-substituted acrylate can be exemplified, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups can be preferably exemplified. More specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. can be exemplified, and methyl or ethyl is more preferred, and methyl is particularly preferred.

[0171] In formula (a1-r-1), as the hydrocarbon group of Ra’ 3 , linear or branched alkyl groups, or cyclic hydrocarbon groups can be exemplified.

[0172] The carbon number of the linear alkyl group is preferably from 1 to 5, more preferably from 1 to 4, and still more preferably 1 or 2. Specifically, examples include methyl, ethyl, n-propyl, n-butyl, n-pentyl, etc. Among them, methyl, ethyl or n-butyl is preferred, and methyl or ethyl is more preferred.

[0173] The carbon number of the branched alkyl group is preferably from 3 to 10, and more preferably from 3 to 5. Specifically, examples include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, 2,2-dimethylbutyl, etc., and isopropyl is preferred.

[0174] In the case of Ra’ 3 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.

[0175] As the aliphatic hydrocarbon group of the monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred, and specifically, examples include cyclopentane, cyclohexane, etc.

[0176] As the aliphatic hydrocarbon group of the polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred. As the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferred, and specifically, examples include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0177] In the case of Ra’ 3 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

[0178] If the aromatic ring is a cyclic conjugated system having 4n + 2 π electrons, there is no particular limitation, and it may be monocyclic or polycyclic. The carbon number of the aromatic ring is preferably from 5 to 30, more preferably from 5 to 20, still more preferably from 6 to 15, and particularly preferably from 6 to 12.

[0179] As the aromatic ring, specifically, examples include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, phenanthrene; aromatic heterocycles obtained by substituting a part of the carbon atoms constituting the aromatic hydrocarbon ring with heteroatoms, etc. As the heteroatoms in the aromatic heterocycle, examples include an oxygen atom, a sulfur atom, a nitrogen atom, etc. As the aromatic heterocycle, specifically, examples include a pyridine ring, a thiophene ring, etc.

[0180] As Ra’ 3The aromatic hydrocarbon group, specifically, examples thereof include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl or heteroaryl); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group obtained by substituting one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocyclic ring with an alkylene group (such as arylalkyl such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0181] Ra’ 3 The cyclic hydrocarbon group in may have a substituent. As such a substituent, for example, -R P1 、-R P2 -O-R P1 、-R P2 -CO-R P1 、-R P2 -CO-OR P1 、-R P2 -O-CO-R P1 、-R P2 -OH、-R P2 -CN or -R P2 -COOH (hereinafter, these substituents are collectively referred to as “Ra x5 ”) etc.

[0182] Here, R P1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. In addition, R P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Among them, some or all of the hydrogen atoms of the linear saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group of R P1 and R P2 may be substituted with fluorine atoms. The above-mentioned aliphatic cyclic hydrocarbon group may have one or more of the above-mentioned substituents alone, or may have one or more of various above-mentioned substituents.

[0183] As the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, etc. can be cited.

[0184] As a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, for example, monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclododecyl, etc.; polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octyl, tricyclo[5.2.1.02,6]decyl, tricyclo[3.3.1.13,7]decyl, tetracyclo[6.2.1.13,6.02,7]dodecyl, adamantyl, etc.

[0185] As a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, for example, groups obtained by removing one hydrogen atom from aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene, etc.

[0186] In the case of bonding to any one of Ra’ 3 and Ra’ 1 、Ra’ 2 to form a ring, as the cyclic group, a four- to seven-membered ring is preferred, and a four- to six-membered ring is more preferred. Specific examples of the cyclic group include tetrahydropyranyl, tetrahydrofuranyl, etc.

[0187] Tert-alkyl ester type acid dissociable group:

[0188] As an acid dissociable group for protecting the carboxyl group in the above polar group, for example, an acid dissociable group represented by the following general formula (a1-r-2) can be cited.

[0189] In addition, for the sake of convenience of explanation, hereinafter, the group composed of an alkyl group in the acid dissociable group represented by the following formula (a1-r-2) is sometimes referred to as a "tert-alkyl ester type acid dissociable group".

[0190] [Chemical formula 11]

[0191]

[0192] [In the formula, Ra’ 4 ~Ra’ 6 are each a hydrocarbon group, and Ra’ 5 、Ra’ 6 can bond to each other to form a ring.]

[0193] As the hydrocarbon group of Ra’ 4 , examples include linear or branched alkyl groups, chain or cyclic alkenyl groups, or cyclic hydrocarbon groups.

[0194] Ra’ 4 The linear or branched alkyl groups, cyclic hydrocarbon groups (aliphatic hydrocarbon groups as monocyclic groups, aliphatic hydrocarbon groups as polycyclic groups, aromatic hydrocarbon groups) in can be cited as the same groups as those of the aforementioned Ra’ 3 .

[0195] Ra’ 4 The alkenyl group in the form of a chain or a ring preferably has 2 to 10 carbon atoms.

[0196] As Ra’ 5 , Ra’ 6 For the hydrocarbon group of, the same hydrocarbon groups as those of the aforementioned Ra’ 3 can be exemplified.

[0197] In the case where Ra’ 5 and Ra’ 6 are bonded to each other to form a ring, the groups represented by the following general formula (a1-r2-1), the groups represented by the following general formula (a1-r2-2), and the groups represented by the following general formula (a1-r2-3) can be preferably exemplified.

[0198] On the other hand, in the case where Ra’ 4 to Ra’ 6 are not bonded to each other and are independent hydrocarbon groups, the groups represented by the following general formula (a1-r2-4) can be preferably exemplified.

[0199] [Chemical formula 12]

[0200]

[0201] In formula (a1-r2-1), Ra’ 10 represents a linear or branched alkyl group having 1 to 12 carbon atoms, a part of which may be substituted by a halogen atom or a heteroatom-containing group. Ra’ 11 represents a group that forms an aliphatic cyclic group together with the carbon atom to which it is bonded. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Part or all of the hydrogen atoms of the cyclic hydrocarbon group may be substituted. Ra 10 to Ra 101 to Ra 103 are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Part or all of the hydrogen atoms of the linear saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra 101 to Ra 103 can 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 is an aromatic hydrocarbon group that may have a substituent. In formula (a1-r2-4), Ra’ 12 and Ra’ 13Independently of each other, they are a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms of the linear saturated hydrocarbon group may be substituted. Ra’ 14 is a hydrocarbon group which may have a substituent. * represents a chemical bond.]

[0202] In the above formula (a1-r2-1), Ra’ 10 is a linear or branched alkyl group having 1 to 12 carbon atoms, part of which may be substituted by a halogen atom or a heteroatom-containing group.

[0203] As the linear alkyl group in Ra’ 10 , it has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms.

[0204] As the branched alkyl group in Ra’ 10 , groups similar to those of the aforementioned Ra’ 3 can be exemplified.

[0205] Part of the alkyl group in Ra’ 10 may be substituted by a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted by a halogen atom or a heteroatom-containing group. In addition, some of the carbon atoms (such as methylene) constituting the alkyl group may be substituted by a heteroatom-containing group.

[0206] As the heteroatoms mentioned herein, oxygen atom, sulfur atom, and nitrogen atom can be exemplified. As the heteroatom-containing groups, (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, -S(=O)2-O- etc. can be exemplified.

[0207] In formula (a1-r2-1), Ra’ 11 (an aliphatic cyclic group formed together with the carbon atom bonded to Ra’ 10 ) is preferably a group exemplified as an aliphatic hydrocarbon group (alicyclic hydrocarbon group) of a monocyclic group or a polycyclic group in Ra’ 3 in formula (a1-r-1). Among them, a monocyclic alicyclic hydrocarbon group is preferred. Specifically, cyclopentyl and cyclohexyl are more preferred, and cyclopentyl is further preferred.

[0208] In formula (a1-r2-2), as the cyclic hydrocarbon group formed by Xa and Ya together, a group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in Ra’ 3 in the above formula (a1-r-1) can be exemplified.

[0209] The cyclic hydrocarbon group formed by Xa and Ya may have a substituent. As such a substituent, groups similar to those which the cyclic hydrocarbon group in the above Ra' 3 may have can be exemplified.

[0210] In formula (a1-r2-2), as Ra 101 ~Ra 103 a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, etc. can be exemplified.

[0211] As Ra 101 ~Ra 103 a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, for example, monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclododecyl, etc.; polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octyl, tricyclo[5.2.1.02,6]decyl, tricyclo[3.3.1.13,7]decyl, tetracyclo[6.2.1.13,6.02,7]dodecyl, adamantyl, etc. can be exemplified.

[0212] Among them, from the viewpoint of ease of synthesis, Ra 101 ~Ra 103 are preferably a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, and among them, more preferably a hydrogen atom, methyl, ethyl, and particularly preferably a hydrogen atom.

[0213] As the substituents which the linear saturated hydrocarbon group or aliphatic cyclic saturated hydrocarbon group represented by the above Ra 101 ~Ra 103 has, for example, groups similar to those of the above Ra x5 can be exemplified.

[0214] Ra 101 ~Ra 103 Two or more of them bond to each other to form a cyclic structure, thereby generating a group containing a carbon-carbon double bond. As such a group containing a carbon-carbon double bond, for example, cyclopentenyl, cyclohexenyl, methylcyclopentenyl, methylcyclohexenyl, cyclopentylene vinyl, cyclohexylene vinyl, etc. can be exemplified. Among them, from the viewpoint of ease of synthesis, cyclopentenyl, cyclohexenyl, cyclopentylene vinyl are preferred.

[0215] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa and Yaa is preferably a group exemplified as the aliphatic hydrocarbon group of the monocyclic group or polycyclic group of Ra' 3 in formula (a1-r-1).

[0216] In formula (a1-r2-3), as Ra104 The aromatic hydrocarbon group in 104 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene or naphthalene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.

[0217] As Ra in formula (a1-r2-3) 104 Examples of the substituents that can be possessed include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), an alkyloxycarbonyl group, etc.

[0218] In formula (a1-r2-4), Ra' 12 and Ra' 13 are each independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. As the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in Ra' 12 and Ra' 13 examples thereof include the same groups as the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in the above Ra 101 to Ra 103 One or all of the hydrogen atoms possessed by the linear saturated hydrocarbon group may be substituted.

[0219] Ra' 12 and Ra' 13 preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, still more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.

[0220] When the linear saturated hydrocarbon group represented by the above Ra' 12 and Ra' 13 is substituted, examples of the substituent include the same groups as those of the above Ra x5 the same.

[0221] In formula (a1-r2-4), Ra' 14 is a hydrocarbon group which may have a substituent. As the hydrocarbon group in Ra' 14 examples thereof include a linear or branched alkyl group or a cyclic hydrocarbon group.

[0222] Ra' 14The number of carbon atoms of the straight-chain alkyl group therein is preferably 1 to 5, more preferably 1 to 4, and still more preferably 1 or 2. Specifically, examples include methyl, ethyl, n-propyl, n-butyl, n-pentyl, etc. Among them, methyl, ethyl or n-butyl is preferred, and methyl or ethyl is more preferred.

[0223] Ra’ 14 The number of carbon atoms of the branched-chain alkyl group therein is preferably 3 to 10, more preferably 3 to 5. Specifically, examples include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, 2,2-dimethylbutyl, etc., and isopropyl is preferred.

[0224] In Ra’ 14 When Ra’ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.

[0225] As the aliphatic hydrocarbon group of the monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred, and specifically, examples include cyclopentane, cyclohexane, etc.

[0226] As the aliphatic hydrocarbon group of the polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred. As the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferred, and specifically, examples include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0227] As Ra’ 14 The aromatic hydrocarbon group in can be exemplified by the same groups as the aromatic hydrocarbon group in Ra 104 Among them, Ra’ 14 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene, and most preferably a group obtained by removing one or more hydrogen atoms from naphthalene.

[0228] As Ra’ 14 The substituents that can be possessed can be exemplified by the same substituents as the substituents that Ra 104 can have.

[0229] In Ra’ in formula (a1-r2-4) 14 When it is a naphthyl group, the bonding position to the tertiary carbon atom in the formula (a1-r2-4) can be any of the 1-position or 2-position of the naphthyl group.

[0230] In Ra’ in formula (a1-r2-4) 14When it is an anthryl group, the position bonded to the tertiary carbon atom in the formula (a1-r2-4) can be any one of the 1-position, 2-position or 9-position of the anthryl group.

[0231] Specific examples of the group represented by the formula (a1-r2-1) are exemplified below.

[0232] [Chemical formula 13]

[0233]

[0234] [Chemical formula 14]

[0235]

[0236] [Chemical formula 15]

[0237]

[0238] Specific examples of the group represented by the formula (a1-r2-2) are exemplified below.

[0239] [Chemical formula 16]

[0240]

[0241] [Chemical formula 17]

[0242]

[0243] [Chemical formula 18]

[0244]

[0245] Specific examples of the group represented by the formula (a1-r2-3) are exemplified below.

[0246] [Chemical formula 19]

[0247]

[0248] Specific examples of the group represented by the formula (a1-r2-4) are exemplified below.

[0249] [Chemical formula 20]

[0250]

[0251] Tertiary alkoxycarbonyl acid dissociable group:

[0252] As the acid dissociable group for protecting the hydroxyl group in the polar group, for example, the acid dissociable group represented by the following general formula (a1-r-3) can be exemplified (for the sake of convenience, it is sometimes referred to as "tertiary alkoxycarbonyl acid dissociable group") below.

[0253] [Chemical formula 21]

[0254]

[0255] [wherein, Ra' 7 ~Ra' 9 are each an alkyl group.]

[0256] In formula (a1-r-3), Ra' 7 ~Ra' 9 are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms.

[0257] In addition, the total number of carbon atoms of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0258] As the structural unit (a1), examples include a structural unit derived from an acrylate in which a hydrogen atom bonded to a carbon atom at the α-position can be substituted with a substituent, a structural unit derived from acrylamide, a structural unit in which at least a part of the hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected with a substituent containing the acid-decomposable group, a structural unit in which at least a part of the hydrogen atoms in -C(=O)-OH of a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative is protected with a substituent containing the acid-decomposable group, and the like.

[0259] As the structural unit (a1), among the above structural units, a structural unit derived from an acrylate in which a hydrogen atom bonded to a carbon atom at the α-position can be substituted with a substituent is preferred.

[0260] As a preferred specific example of the structural unit (a1), a structural unit represented by the following general formula (a1-1) or (a1-2) can be cited.

[0261] [Chemical formula 22]

[0262]

[0263] [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. Va 1 is a divalent hydrocarbon group which may have an ether bond. n a1 is an integer of 0 to 2. Ra 1 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-2). Wa 1 is an n a2 +1-valent hydrocarbon group, n a2 is an integer of 1 to 3, and Ra 2 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).]

[0264] R in the formula (a1-1) is the same as R in the general formula (a0-1). As R in the formula (a1-1), groups the same as those exemplified for R in the general formula (a0-1) can be exemplified, and the preferred examples are also the same.

[0265] In the formula (a1-1), Va 1 The divalent hydrocarbon group in can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the divalent hydrocarbon group in Va 1 , groups the same as those exemplified for the divalent hydrocarbon group which may have a substituent in Va 01 in the general formula (a0-1) can be exemplified, and the preferred examples are also the same.

[0266] In the formula (a1-1), Ra 1 is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0267] In the formula (a1-2), Wa 1 The n a2 in the +1-valent hydrocarbon group can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity, and can be saturated or unsaturated, and is usually preferably saturated. As the aliphatic hydrocarbon group, linear or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in the structure, or groups formed by combining linear or branched aliphatic hydrocarbon groups with aliphatic hydrocarbon groups containing a ring in the structure can be exemplified.

[0268] The n a2 in the +1-valent is preferably 2 to 4 valent, more preferably 2 or 3 valent.

[0269] In the formula (a1-2), Ra 2 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0270] Specific examples of the structural unit represented by the formula (a1-1) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0271] [Chemical formula 23]

[0272]

[0273] [Chemical formula 24]

[0274]

[0275] [Chemical formula 25]

[0276]

[0277] [Chemical Formula 26]

[0278]

[0279] [Chemical Formula 27]

[0280]

[0281] [Chemical Formula 28]

[0282]

[0283] [Chemical Formula 29]

[0284]

[0285] [Chemical Formula 30]

[0286]

[0287] The structural unit (a1) possessed by the (A1) component can be one type or two or more types.

[0288] Among them, as the structural unit (a1), a structural unit represented by the following general formula (a1-1-1) is preferred.

[0289] [Chemical Formula 31]

[0290]

[0291] [In the formula, Ra 1” is an acid dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4).]

[0292] In the formula (a1-1-1), R, Va 1 and n a1 are the same as R, Va 1 and n a1 in the formula (a1-1).

[0293] The description of the acid dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4) is as described above.

[0294] In the formula (a1-1-1), Ra 1” is preferably an acid dissociable group represented by the general formula (a1-r2-1) in the above.

[0295] The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol% with respect to the total of all the structural units constituting the component (A1) (100 mol%).

[0296] By making the proportion of the structural unit (a1) within the above preferred range, the efficiency of the deprotection reaction and the developability can be appropriately ensured, and thus the effects of the present invention can be more easily obtained.

[0297] Regarding the structural unit (a10):

[0298] The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0299] [Chemical formula 32]

[0300]

[0301] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya x1 is a single bond or a divalent linking group. Wa x1 is an aromatic hydrocarbon group which may have a substituent. n ax1 is an integer of 1 or more.]

[0302] R in the formula (a10-1) is the same as R in the general formula (a0-1). As R in the formula (a10-1), groups the same as those exemplified for R in the general formula (a0-1) can be exemplified, and the preferred examples are also the same.

[0303] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group.

[0304] In the chemical formula, as Ya x1 as the divalent linking group, there is no particular limitation, and examples of preferred linking groups include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, etc. As Ya x1 as the divalent linking group, groups the same as those exemplified for Va 01 in the general formula (a0-1) can be exemplified.

[0305] Among them, as Ya x1 , it is preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-].[[]END]]

[0306] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent.

[0307] As the aromatic hydrocarbon group in Wa x1 , a group obtained by removing (n ax1 +1) hydrogen atoms from an aromatic ring which may have a substituent can be exemplified. Here, if the aromatic ring is a cyclic conjugated system having 4n + 2 π electrons, there is no particular limitation, and it may be monocyclic or polycyclic. The number of carbon atoms of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specifically, as the aromatic ring, aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene can be exemplified; aromatic heterocycles obtained by substituting a part of the carbon atoms constituting the aromatic hydrocarbon ring with heteroatoms, etc. As the heteroatoms in the aromatic heterocycle, oxygen atoms, sulfur atoms, nitrogen atoms, etc. can be exemplified. Specifically, as the aromatic heterocycle, a pyridine ring, a thiophene ring, etc. can be exemplified.

[0308] In addition, as the aromatic hydrocarbon group in Wa x1 , a group obtained by removing (n ax1 +1) hydrogen atoms from an aromatic compound containing two or more aromatic rings which may have a substituent (such as biphenyl, fluorene, etc.) can also be exemplified.

[0309] Among the above, as Wa x1 , a group obtained by removing (n ax1 +1) hydrogen atoms from benzene, naphthalene, anthracene or biphenyl is preferred, a group obtained by removing (n ax1 +1) hydrogen atoms from benzene or naphthalene is more preferred, and a group obtained by removing (n ax1 +1) hydrogen atoms from benzene is still more preferred.

[0310] The aromatic hydrocarbon group in Wa x1 may have a substituent or may not have a substituent. As the substituent, for example, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, etc. can be exemplified. As the alkyl group, alkoxy group, halogen atom, and haloalkyl group of the substituent, the same groups as those exemplified as the substituent of the cyclic aliphatic hydrocarbon group in Ya x1 can be exemplified. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, still more preferably an ethyl group or a methyl group, and particularly preferably a methyl group. The aromatic hydrocarbon group in Wa x1 preferably does not have a substituent.

[0311] In the formula (a10-1), n ax1is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, still more preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0312] Specific examples of the structural unit (a10) represented by the formula (a10-1) are shown below.

[0313] In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0314] [Chemical formula 33]

[0315]

[0316] [Chemical formula 34]

[0317]

[0318] [Chemical formula 35]

[0319]

[0320] [Chemical formula 36]

[0321]

[0322] The structural unit (a10) possessed by the component (A1) may be one kind or two or more kinds.

[0323] When the component (A1) has the structural unit (a10), the proportion of the structural unit (a10) in the component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1).

[0324] By making the proportion of the structural unit (a10) within the above preferred range, the efficiency of supplying protons in the resist film is improved, and the developability solubility is easily ensured.

[0325] Regarding the structural unit (a2):

[0326] The component (A1) may further have a structural unit (a2) containing a lactone ring group, a -SO2- ring group or a carbonate ring group (excluding the structural units belonging to the structural unit (a0)).

[0327] When the component (A1) is used for forming a resist film, the lactone ring-containing group, -SO2-ring-containing group or carbonate ring-containing group of the structural unit (a2) is effective in improving the adhesion of the resist film to the substrate. In addition, by having the structural unit (a2), effects such as appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development are achieved, and the lithography characteristics and the like become good.

[0328] The lactone ring-containing group in the structural unit (a2) is not particularly limited, and any lactone ring-containing group can be used. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be exemplified.

[0329] [Chemical formula 37]

[0330]

[0331] [In the formula, Ra' 21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl 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 ring-containing group, a carbonate ring-containing group or a -SO2-ring-containing group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom or a sulfur atom, n' is an integer of 0 to 2, and m' is 0 or 1.]

[0332] In the general formulas (a2-r-1) to (a2-r-7), as 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. Specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, etc. can be exemplified. Among these, methyl or ethyl is preferred, and methyl is particularly preferred.

[0333] As Ra' 21 the alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, groups obtained by connecting the alkyl groups exemplified as the Ra' 21 in to an oxygen atom (-O-) can be exemplified.

[0334] As Ra' 21 the halogen atom in is preferably a fluorine atom.

[0335] As Ra' 21 the haloalkyl group in can be exemplified by a group in which a part or all of the hydrogen atoms of the alkyl group in the Ra' 21 are substituted by the halogen atom. As the haloalkyl group, a fluoroalkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0336] In Ra’ 21 in “-COOR” and “-OC(=O)R” in, R” is each a hydrogen atom, an alkyl group, a lactone ring-containing group, a carbonate ring-containing group or a -SO2-ring-containing group.

[0337] As the alkyl group in R”, it may be any of linear, branched or cyclic, and the number of carbon atoms is preferably 1 to 15.

[0338] When R” is a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 5, and particularly preferably methyl or ethyl.

[0339] When R” is a cyclic alkyl group, the number of carbon atoms is preferably 3 to 15, more preferably 4 to 12, and most preferably 5 to 10. Specifically, examples include groups obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluoroalkyl group; groups obtained by removing one or more hydrogen atoms from a polycycloalkane such as a bicycloalkane, a tricycloalkane or a tetracycloalkane. More specifically, examples include groups obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane; groups obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane.

[0340] As the lactone ring-containing group in R”, examples include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7) respectively.

[0341] As the carbonate ring-containing group in R”, similar to the carbonate ring-containing group described later, specifically, examples include groups represented by the general formulas (ax3-r-1) to (ax3-r-3) respectively.

[0342] As the -SO2-ring-containing group in R”, similar to the -SO2-ring-containing group described later, specifically, examples include groups represented by the general formulas (a5-r-1) to (a5-r-4) respectively.

[0343] As Ra’ 21 the hydroxyalkyl group in, preferably a hydroxyalkyl group having 1 to 6 carbon atoms, specifically, examples include the Ra’ 21 a group obtained by substituting at least one hydrogen atom of the alkyl group in with a hydroxy group.

[0344] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), as the alkylene group having 1 to 5 carbon atoms in A'', a linear or branched alkylene group is preferred, and examples thereof include a methylene group, an ethylene group, a n-propylene group, an isopropyl group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups having -O- or -S- interposed at the terminal or between carbon atoms of the alkylene group, and examples thereof include O-CH2-, -CH2-O-CH2-, -S-CH2-, -CH2-S-CH2-, etc. As A'', an alkylene group having 1 to 5 carbon atoms or -O- is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is most preferred.

[0345] Specific examples of the groups represented by the general formulas (a2-r-1) to (a2-r-7) are shown below.

[0346] [Chemical formula 38]

[0347]

[0348] [Chemical formula 39]

[0349]

[0350] "A cyclic group containing -SO2-" means a cyclic group having a ring containing -SO2- in its ring skeleton. Specifically, it is a cyclic group in which the sulfur atom (S) in -SO2- forms a part of the ring skeleton of the cyclic group. In the ring skeleton, the ring containing -SO2- is counted as the first ring. When there is only this ring, it is called a monocyclic group, and when there is also another ring structure, it is called a polycyclic group regardless of its structure. The cyclic group containing -SO2- can be a monocyclic group or a polycyclic group.

[0351] The cyclic group containing -SO2- is particularly preferably a cyclic group containing -O-SO2- in its ring skeleton, that is, a sultone ring-containing cyclic group in which -O-S- in -O-SO2- forms a part of the ring skeleton.

[0352] More specifically, examples of the cyclic group containing -SO2- include groups represented by the following general formulas (a5-r-1) to (a5-r-4), respectively.

[0353] [Chemical formula 40]

[0354]

[0355] [In the formula, Ra' 51Each is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl 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 ring-containing group, a carbonate ring-containing group or a -SO2-ring-containing group; A″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n′ is an integer of 0 to 2.

[0356] In the general formulas (a5-r-1) to (a5-r-2), A″ is the same as A″ in the general formulas (a2-r-2), (a2-r-3) and (a2-r-5).

[0357] As Ra′ 51 For the alkyl group, alkoxy group, halogen atom, haloalkyl group, -COOR″, -OC(═O)R″, hydroxyalkyl group in 21 the groups exemplified in the description of Ra′ in the general formulas (a2-r-1) to (a2-r-7) may be cited as the same groups.

[0358] Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are given below. In the formulas, “Ac” represents an acetyl group.

[0359] [Chemical formula 41]

[0360]

[0361] [Chemical formula 42]

[0362]

[0363] [Chemical formula 43]

[0364]

[0365] “Carbonate ring-containing group” means a cyclic group containing a ring (carbonate ring) containing -O-C(═O)-O- in its ring skeleton. The carbonate ring is denoted as the first ring. In the case of only a carbonate ring, it is called a monocyclic group, and in the case of having other ring structures, it is called a polycyclic group regardless of its structure. The carbonate ring-containing group can be a monocyclic group or a polycyclic group.

[0366] As the cyclic group containing a carbonate ring, there is no particular limitation, and any cyclic group containing a carbonate ring can be used. Specifically, the groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) can be cited.

[0367] [Chemical formula 44]

[0368]

[0369] [wherein, Ra' x31 is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl 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 ring-containing group, a carbonate ring-containing group or a -SO2-ring-containing group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and p' is an integer of 0 to 3, and q' is 0 or 1.]

[0370] In the general formulas (ax3-r-2) to (ax3-r-3), A" is the same as A" in the general formulas (a2-r-2), (a2-r-3) and (a2-r-5).

[0371] As Ra' 31 for the alkyl group, alkoxy group, halogen atom, haloalkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group, groups the same as those exemplified in the description of Ra' 21 in the general formulas (a2-r-1) to (a2-r-7) can be exemplified respectively.

[0372] Specific examples of the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) are exemplified below.

[0373] [Chemical formula 45]

[0374]

[0375] As the structural unit (a2), preferably, it is a structural unit derived from an acrylate in which a hydrogen atom bonded to a carbon atom at the α-position can be substituted by a substituent.

[0376] The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0377] [Chemical formula 46]

[0378]

[0379] [wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a haloalkyl group having 1 to 5 carbon atoms. Ya 21 is a single bond or a divalent linking group. La 21 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, and R' represents a hydrogen atom or a methyl group. Among them, when La 21 is -O-, Ya 21 will not be -CO-. Ra 21 is a lactone ring-containing group, a carbonate ring-containing group or a -SO2-ring-containing group.]

[0380] R in the formula (a2-1) is the same as R in the general formula (a0-1). As R in the formula (a2-1), groups the same as those exemplified for R in the general formula (a0-1) can be exemplified, and the preferred examples are also the same.

[0381] In the formula (a2-1), as Ya 21 the divalent linking group therein is not particularly limited, and divalent hydrocarbon groups which may have substituents, divalent linking groups containing heteroatoms, etc. can be preferably exemplified. As Ya 21 the divalent linking group therein, groups the same as those exemplified for Va 01 in the general formula (a0-1) can be exemplified.

[0382] Among them, as Ya 21 , a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof is preferred.

[0383] In the formula (a2-1), Ra 21 is a lactone ring-containing group, a -SO2-ring-containing group or a carbonate ring-containing group.

[0384] As the lactone ring-containing group, -SO2-ring-containing group, and carbonate ring-containing group in Ra 21 , groups respectively represented by the general formulas (a2-r-1) to (a2-r-7), groups respectively represented by the general formulas (a5-r-1) to (a5-r-4), and groups respectively represented by the general formulas (ax3-r-1) to (ax3-r-3) can be preferably exemplified respectively.

[0385] Among them, a lactone ring-containing group or a -SO2-ring-containing group is preferred, and groups respectively represented by the general formulas (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r-1) are more preferred. Specifically, any of the groups respectively represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1), (r-sl-1-1), (r-sl-1-18) is more preferred.

[0386] The structural unit (a2) possessed by the component (A1) may be one kind or two or more kinds.

[0387] When the component (A1) has the structural unit (a2), the proportion of the structural unit (a2) is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, still more preferably 15 to 35 mol%, and particularly preferably 20 to 30 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1).

[0388] If the proportion of the structural unit (a2) is at least the lower limit of the preferred range, the effects brought about by containing the structural unit (a2) can be fully obtained through the above effects. If it is at most the upper limit, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0389] Regarding the structural unit (a3):

[0390] (A1) component may further have a structural unit (a3) containing an aliphatic hydrocarbon group having a polar group (excluding the structural units belonging to the structural unit (a1) or the structural unit (a2)). By making the (A1) component have the structural unit (a3), the hydrophilicity of the (A) component is improved, which contributes to the improvement of resolution. In addition, the acid diffusion length can be appropriately adjusted.

[0391] Examples of the polar group include a hydroxyl group, a cyano group, a carboxyl group, a hydroxyalkyl group in which a part of the hydrogen atoms of an alkyl group are substituted by fluorine atoms, etc., and a hydroxyl group is particularly preferred.

[0392] Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group), and a cyclic aliphatic hydrocarbon group (cyclic group). As the cyclic group, it may be a monocyclic group or a polycyclic group, and can be appropriately selected and used from the cyclic groups frequently mentioned in the resin for an ArF excimer laser resist composition, for example.

[0393] When the cyclic group is a monocyclic group, it preferably has 3 to 10 carbon atoms. Among them, a structural unit derived from an acrylate containing an aliphatic monocyclic group is more preferred, and the aliphatic monocyclic group contains a hydroxyl group, a cyano group, a carboxyl group, or a hydroxyalkyl group in which a part of the hydrogen atoms of an alkyl group are substituted by fluorine atoms. Examples of the monocyclic group include a group obtained by removing two or more hydrogen atoms from a monocycloalkane. Specifically, groups obtained by removing two or more hydrogen atoms from monocycloalkanes such as cyclopentane, cyclohexane, and cyclooctane can be cited. Among these monocyclic groups, a group obtained by removing two or more hydrogen atoms from cyclopentane and a group obtained by removing two or more hydrogen atoms from cyclohexane are preferably industrially used.

[0394] In the case where the cyclic group is a polycyclic group, the number of carbon atoms of the polycyclic group is more preferably 7 to 30. Among them, a structural unit derived from an acrylate containing an aliphatic polycyclic group is more preferably used, and the aliphatic polycyclic group contains a hydroxyl group, a cyano group, a carboxyl group, or a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted by a fluorine atom. As the polycyclic group, groups obtained by removing two or more hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc. can be exemplified. Specifically, groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane can be cited. Among these polycyclic groups, groups obtained by removing two or more hydrogen atoms from adamantane, groups obtained by removing two or more hydrogen atoms from norbornane, and groups obtained by removing two or more hydrogen atoms from tetracyclododecane are preferably used industrially.

[0395] As the structural unit (a3), as long as it contains an aliphatic hydrocarbon group having a polar group, there is no particular limitation, and any structural unit can be used.

[0396] As the structural unit (a3), a structural unit derived from an acrylate in which a hydrogen atom bonded to a carbon atom at the α-position can be substituted by a substituent and containing an aliphatic hydrocarbon group having a polar group is preferred.

[0397] When the hydrocarbon group in the aliphatic hydrocarbon group having a polar group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, a structural unit derived from 2-hydroxyethyl acrylate is preferred.

[0398] In addition, when the hydrocarbon group in the aliphatic hydrocarbon group having a polar group is a polycyclic group, structural units represented by the following formula (a3-1), structural units represented by the formula (a3-2), and structural units represented by the formula (a3-3) can be exemplified as preferred structural units as the structural unit (a3); when the hydrocarbon group in the aliphatic hydrocarbon group having a polar group is a monocyclic group, a structural unit represented by the formula (a3-4) can be exemplified as a preferred structural unit as the structural unit (a3).

[0399] [Chemical formula 47]

[0400]

[0401] [In the formula, R is the same as described above, j is an integer from 1 to 3, k is an integer from 1 to 3, t' is an integer from 1 to 3, l is an integer from 0 to 5, and s is an integer from 1 to 3.]

[0402] In formula (a3-1), j is preferably 1 or 2, more preferably 1. When j is 2, it is preferred that the hydroxyl group is bonded to the 3-position and 5-position of the adamantyl group. When j is 1, it is preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group. j is preferably 1, and particularly preferably the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0403] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5-position or 6-position of the norbornyl group.

[0404] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. They preferably have a 2-norbornyl group or 3-norbornyl group bonded to the terminal of the carboxyl group of acrylic acid. The fluoroalkyl alcohol is preferably bonded to the 5- or 6-position of the norbornyl group.

[0405] In formula (a3-4), t' is preferably 1 or 2. l is preferably 0 or 1. s is preferably 1. The fluoroalkyl alcohol is preferably bonded to the 3- or 5-position of the cyclohexyl group.

[0406] (A1) component may have one or more than two structural units (a3).

[0407] When the (A1) component has the structural unit (a3), the proportion of the structural unit (a3) is preferably 1 to 30 mol%, more preferably 2 to 25 mol%, and further preferably 5 to 20 mol% relative to the total (100 mol%) of all the structural units constituting the (A1) component.

[0408] By making the proportion of the structural unit (a3) be above the preferred lower limit value, the effect brought by containing the structural unit (a3) can be fully obtained through the above effects. If it is below the preferred upper limit value, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0409] Regarding the structural unit (a4):

[0410] (A1) component may also have a structural unit (a4) containing an acid non-dissociable aliphatic cyclic group.

[0411] By making the (A1) component have the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. In addition, the hydrophobicity of the (A) component is increased. The increase in hydrophobicity is particularly helpful for improving resolution, resist pattern shape, etc. in the case of a solvent development process.

[0412] The "acid non-dissociable cyclic group" in the structural unit (a4) is a cyclic group that does not dissociate under the action of the acid even when an acid is generated in the resist composition by exposure (for example, when an acid is generated by a structural unit that generates an acid upon exposure or by the (B) component), and directly remains in the structural unit.

[0413] As the structural unit (a4), for example, a structural unit derived from an acrylate containing an acid non-dissociable aliphatic cyclic group is preferred. A large number of groups known as groups for resin components of resist compositions for ArF excimer lasers, KrF excimer lasers (preferably for ArF excimer lasers), etc. can be used for this cyclic group.

[0414] From the viewpoint of being easily available industrially, this cyclic group is particularly preferably at least one selected from tricyclodecyl, adamantyl, tetracyclododecyl, isobornyl, and norbornyl. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

[0415] As the structural unit (a4), specifically, structural units represented by the following general formulas (a4-1) to (a4-7) can be exemplified.

[0416] [Chemical formula 48]

[0417]

[0418] [In the formula, R α is the same as described above.]

[0419] The structural unit (a4) contained in the component (A1) may be one kind or two or more kinds.

[0420] When the component (A1) contains the structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 40 mol%, more preferably 5 to 20 mol%, relative to the total (100 mol%) of all the structural units constituting the component (A1).

[0421] By setting the proportion of the structural unit (a4) to be not less than the preferred lower limit value, the effects brought about by containing the structural unit (a4) can be fully obtained. On the other hand, by setting it to be not more than the preferred upper limit value, it is easy to achieve a balance with other structural units.

[0422] Regarding the structural unit (st):

[0423] The structural unit (st) is a structural unit derived from styrene or a styrene derivative. "The structural unit derived from styrene" means a structural unit formed by the cleavage of the olefinic double bond of styrene. "The structural unit derived from a styrene derivative" means a structural unit formed by the cleavage of the olefinic double bond of a styrene derivative (excluding the structural unit belonging to the structural unit (a10)).

[0424] "Styrene derivatives" refer to compounds in which at least a part of the hydrogen atoms of styrene are replaced by substituents. Examples of styrene derivatives include compounds in which the hydrogen atom at the α-position of styrene is replaced by a substituent, compounds in which one or more hydrogen atoms on the benzene ring of styrene are replaced by substituents, and compounds in which the hydrogen atom at the α-position of styrene and one or more hydrogen atoms on the benzene ring are replaced by substituents, etc.

[0425] Examples of the substituent that replaces the hydrogen atom at the α-position of substituted styrene include an alkyl group having 1 to 5 carbon atoms or a haloalkyl group having 1 to 5 carbon atoms.

[0426] As the alkyl group having 1 to 5 carbon atoms, a linear or branched alkyl group having 1 to 5 carbon atoms is preferred. Specifically, examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc.

[0427] The haloalkyl group having 1 to 5 carbon atoms is a group in which a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are replaced by halogen atoms. As the halogen atom, a fluorine atom is particularly preferred.

[0428] As the substituent that replaces the hydrogen atom at the α-position of substituted styrene, an alkyl group having 1 to 5 carbon atoms or a fluoroalkyl group having 1 to 5 carbon atoms is preferred, and an alkyl group having 1 to 3 carbon atoms or a fluoroalkyl group having 1 to 3 carbon atoms is more preferred. From the viewpoint of industrial availability, methyl is further preferred.

[0429] Examples of the substituent that replaces the hydrogen atom on the benzene ring of substituted styrene include an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, etc.

[0430] As the alkyl group of the substituent, an alkyl group having 1 to 5 carbon atoms is preferred, and methyl, ethyl, propyl, n-butyl, tert-butyl are more preferred.

[0431] As the alkoxy group of the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, and methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy are more preferred, and methoxy and ethoxy are further preferred.

[0432] As the halogen atom of the substituent, a fluorine atom is preferred.

[0433] Examples of the haloalkyl group of the substituent include a group in which a part or all of the hydrogen atoms of the alkyl group are replaced by the halogen atom.

[0434] As the substituent that replaces the hydrogen atom on the benzene ring of substituted styrene, an alkyl group having 1 to 5 carbon atoms is preferred, methyl or ethyl is more preferred, and methyl is further preferred.

[0435] As the structural unit (st), a structural unit derived preferably from styrene, or a structural unit derived from a styrene derivative in which a hydrogen atom at the α-position of styrene is substituted with an alkyl group having 1 to 5 carbon atoms or a haloalkyl group having 1 to 5 carbon atoms, more preferably a structural unit derived from styrene, or a structural unit derived from a styrene derivative in which a hydrogen atom at the α-position of styrene is substituted with a methyl group, and still more preferably a structural unit derived from styrene.

[0436] (A1) component may have one or more than two kinds of structural units (st).

[0437] When the (A1) component has the structural unit (st), the proportion of the structural unit (st) is preferably 1 to 30 mol%, more preferably 3 to 20 mol%, relative to the total (100 mol%) of all the structural units constituting the (A1) component.

[0438] The (A1) component contained in the resist composition may be used alone or in combination of two or more.

[0439] In the resist composition of the present embodiment, the (A1) component may be exemplified by a polymer compound having a repeating structure of the structural unit (a0).

[0440] As a preferred (A1) component, a polymer compound having a repeating structure of the structural unit (a0) and other structural units may be exemplified. As the (A1) component, for example, a polymer compound having a repeating structure of the structural unit (a0) and the structural unit (a1) may be exemplified.

[0441] In addition to the combination of the above two structural units, the structural units described above may be appropriately combined as the third or more structural units according to the desired effect. For example, as the (A1) component, a polymer compound having a repeating structure of the structural unit (a0), the structural unit (a1), and the structural unit (a2) may be exemplified; and a polymer compound having a repeating structure of the structural unit (a0), the structural unit (a1), and the structural unit (a3) may be exemplified.

[0442] Among them, as the (A1) component, a polymer compound having a repeating structure of the structural unit (a0) and the structural unit (a1) is preferred.

[0443] In this case, the molar ratio of the structural unit (a0) to the structural unit (a1) in the polymer compound (structural unit (a0): structural unit (a1)) is preferably 2:8 to 8:2, more preferably 3:7 to 7:3, and still more preferably 4:6 to 6:4.

[0444] The component (A1) can be produced by dissolving monomers that give rise to respective structural units in a polymerization solvent, and adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl 2,2'-azobis(2-methylpropionate) (e.g., V-601, etc.) thereto for polymerization.

[0445] Alternatively, the component (A1) can be produced by dissolving a monomer that gives rise to the structural unit (a0) and monomers that give rise to structural units other than the structural unit (a0) as needed in a polymerization solvent, adding the radical polymerization initiator as described above thereto for polymerization, and then performing a deprotection reaction.

[0446] In addition, during polymerization, for example, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH can be used in combination to introduce a -C(CF3)2-OH group at the terminal. In this way, a copolymer of a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group is substituted by fluorine atoms is effective in reducing development defects and LER (line edge roughness: uneven irregularities on the sidewall of the line).

[0447] The weight average molecular weight (Mw) of the component (A1) (based on polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and still more preferably 3,000 to 20,000.

[0448] If the Mw of the component (A1) is below the upper limit value preferred in this range, it has sufficient solubility in the resist solvent to be used as a resist. If it is above the lower limit value preferred in this range, the dry etching resistance and the cross-sectional shape of the resist pattern are good.

[0449] The molecular weight distribution coefficient (Mw / Mn) of the component (A1) is not particularly limited, preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. In addition, Mn represents the number average molecular weight.

[0450] ·Regarding the component (A2)

[0451] The resist composition of the present embodiment may use, as the component (A), a substrate component (hereinafter referred to as the “component (A2)”) that does not belong to the component (A1) and whose solubility in a developer changes due to the action of an acid in combination.

[0452] The component (A2) is not particularly limited, and it can be arbitrarily selected and used from a large number of components that have been known as substrate components for chemically amplified resist compositions.

[0453] (Component (A2)) can be used alone as one kind of high molecular compound or low molecular compound, or two or more kinds can be used in combination.

[0454] The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, further preferably 75% by mass or more, and may also be 100% with respect to the total mass of component (A). When this proportion is 25% by mass or more, it is easy to form a resist pattern with excellent lithography characteristics such as high sensitivity, fewer defects, improved resolution, and improved roughness.

[0455] In the resist composition of the present embodiment, the content of component (A) can be adjusted according to the desired resist film thickness and the like.

[0456] <Acid generator component (B)>

[0457] The resist composition of the present embodiment contains, in addition to component (A), an acid generator component (B) ((B) component) that generates acid upon exposure. In the present embodiment, component (B) includes a compound (B1) represented by the following general formula (b1) (hereinafter, sometimes referred to as "(B1) component").

[0458] ·Regarding component (B1)

[0459] Component (B1) is a compound represented by the following general formula (b1). By using component (B1) together with component (A1) having the above structural unit (a0), lithography characteristics such as sensitivity and defect improvement can be improved.

[0460] [Chemical formula 49]

[0461]

[0462] [In the formula, Yb 01 represents a divalent linking group or a single bond. Lb 01 represents -C(=O)-O-, -O-C(=O)-, -O- or -O-C(=O)-Lb 011 -, Lb 011 represents an alkylene group having 1 to 3 carbon atoms. Rb 01 ~Rb 03 each independently represents an alkyl group, and two or more of Rb 01 ~Rb 03 can be bonded to each other to form a ring structure. Rb 04 ~Rb 06 each independently represents an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group or a nitro group. n b04 represents an integer of 0 to 4, and n b05 ~n b06Each independently represents an integer from 0 to 5. X - represents a counteranion. ]

[0463] {Cationic part}

[0464] In the formula (b1), Yb 01 represents a divalent linking group or a single bond. As Yb 01 the divalent linking group in, there is no particular limitation, and examples of preferred ones include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, etc. As Yb 01 the divalent linking group in, examples thereof include the same groups as those exemplified for Va 01 in the general formula (a0-1).

[0465] Among them, as Yb 01 the divalent linking group in, a hydrocarbon group which may contain an oxygen atom is preferred. As the hydrocarbon group, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 6, still more preferably 1 to 3, and particularly preferably 1 or 2. The hydrocarbon group is preferably an aliphatic hydrocarbon group, more preferably a linear or branched aliphatic hydrocarbon group, and still more preferably a linear or branched alkylene group.

[0466] As Yb 01 , a single bond, or a linear or branched alkylene group having 1 to 6 carbon atoms which may contain an ether bond or an ester bond is preferred, more preferably a single bond, a linear or branched alkylene group having 1 to 3 carbon atoms which may contain an ether bond or an ester bond, and still more preferably a single bond, -O-CH2-, -C(=O)-O-CH2-, or -O-CH2-C(=O)-O-CH2-.

[0467] In the formula (b1), Lb 01 represents -C(=O)-O-, -O-C(=O)-, -O-, or -O-C(=O)-Lb 011 -, and Lb 011 represents an alkylene group having 1 to 3 carbon atoms. Lb 011 is preferably ethylene or methylene, and more preferably methylene.

[0468] As Lb 01 , -C(=O)-O- or -O-C(=O)- is preferred, and -C(=O)-O- is more preferred.

[0469] In the formula (b1), Rb 01 ~Rb 03 each independently represents an alkyl group, and two or more of Rb 01 ~Rb 03 can be bonded to each other to form a ring structure. Rb 01 ~Rb03 The alkyl group in it preferably has 1 to 12 carbon atoms, more preferably 2 to 10 carbon atoms. Rb 01 ~Rb 03 Among Rb 01 ~Rb 03 the total carbon number of them is preferably 5 or more, more preferably 6 or more. Rb

[0470] The straight-chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. As specific examples, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, etc. can be cited.

[0471] The branched-chain alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 6 carbon atoms. As specific examples, isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, 2,2-dimethylbutyl, etc. can be cited.

[0472] The cyclic alkyl group preferably has 3 to 12 carbon atoms, more preferably 3 to 10 carbon atoms. As specific examples, the cyclic alkyl group can be monocyclic or polycyclic. As the monocyclic alkyl group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred. Specifically, cyclopentane, cyclohexane, etc. can be cited. As the polycyclic alkyl group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred. As the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferred. Specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. can be cited.

[0473] Rb 01 ~Rb 03 Among Rb 01 ~Rb 03 two or more of them can be bonded to each other to form a ring structure. Rb 01 ~Rb 03 The ring structure formed by bonding two or more of them to each other preferably has 3 to 20 carbon atoms, more preferably 4 to 15 carbon atoms, and further preferably 5 to 12 carbon atoms. As the ring structure, the same groups as those cited as the cyclic alkyl group among Rb

[0474] Rb 01 ~Rb 03 Preferably, two or more of them are bonded to each other to form a ring structure. The ring structure preferably has 5 to 20 carbon atoms, more preferably 5 to 15 carbon atoms, and further preferably 5 to 12 carbon atoms. As specific examples of the ring structure, cyclopentyl, cyclohexyl, adamantyl, norbornyl, etc. can be cited. Among them, as the ring structure, cyclopentyl, cyclohexyl or adamantyl is preferred.

[0475] In the formula (b1), Rb 04 ~Rb 06 each independently represents an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group or a nitro group. The alkyl group, the alkoxy group, and the haloalkyl group preferably have 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The alkyl group, the alkoxy group, and the haloalkyl group may be linear, branched, or cyclic, but are preferably linear or branched, and more preferably linear. The halogen atom and the halogen atom in the haloalkyl group are preferably fluorine atoms.

[0476] n b04 represents an integer from 0 to 4. n b04 is preferably an integer from 0 to 3, more preferably an integer from 0 to 2. n b05 ~n b06 each independently represents an integer from 0 to 5. n b05 ~n b06 is preferably an integer from 0 to 3, more preferably an integer from 0 to 2, and still more preferably 0 or 1.

[0477] The cationic part of the compound represented by the formula (b1) is preferably a cation represented by the following general formula (b1-ca).

[0478] [Chemical formula 50]

[0479]

[0480] [In the formula, Yb 011 represents a divalent linking group represented by any one of the following formulas (ca-y1-1) to (ca-y1-5). Rb 011 represents a cyclic alkyl group which may have a substituent. Rb 04 ~Rb 06 and n b04 are the same as those in the general formula (b1).]

[0481] [Chemical formula 51]

[0482]

[0483] [In the formula, * is a chemical bond bonded to the carbon atom of the phenyl group in the formula (b1-ca). ** is a chemical bond bonded to Rb 011 in the formula (b1-ca).]

[0484] Yb in the formula (b1-ca) 011 represents a divalent linking group represented by any one of the formulas (ca-y1-1) to (ca-y1-5). Yb 011Preferably a group represented by formula (ca-y1-1) or formula (ca-y1-2).

[0485] Rb in the formula (b1-ca) 011 represents a cyclic alkyl group which may have a substituent. The cyclic alkyl group preferably has 5 to 20 carbon atoms, more preferably 5 to 15 carbon atoms, and still more preferably 5 to 12 carbon atoms. The cyclic alkyl group may be a monocyclic group or a polycyclic group. Specific examples of the cyclic alkyl group include the same groups as those exemplified for the cyclic alkyl group formed by bonding two or more of Rb 01 ~Rb 03 in the formula (b1).

[0486] As the substituent that the cyclic alkyl group of Rb 011 may have, a linear or branched alkyl group can be exemplified. The linear or branched alkyl group as the substituent preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and still more preferably 1 or 2 carbon atoms.

[0487] Specific examples of the cationic part of the compound represented by the formula (b1-ca) are shown below.

[0488] [Chemical formula 52]

[0489]

[0490] Among them, as the cationic part, a cation represented by any one of the formulas (b1-ca-2) to (b1-ca-14) is preferred, and a cation represented by any one of (b1-ca-2) to (b1-ca-11) is more preferred.

[0491] {Anionic part}

[0492] In the formula (b1), X - represents a counter anion. There is no particular limitation on this X - , and an anion known as the anionic part of an acid generator component for a resist composition can be appropriately used.

[0493] For example, as X - , an anion represented by any one of the following general formulas (b1-an1) to (b1-an3) can be exemplified.

[0494] [Chemical formula 53]

[0495]

[0496] [In the formula, R 101 and R 104 ~R 108Each independently is a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. R 104 and R 105 may bond to each other to form a ring structure. R 102 is a fluoroalkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 to V 103 each independently is a single bond, an alkylene group or a fluoroalkylene group. L 101 to L 102 each independently is a single bond or an oxygen atom. L 103 to L 105 each independently is a single bond, -CO- or -SO2-. ]

[0497] {Anionic moiety}

[0498] · An anion represented by formula (b-an1)

[0499] In formula (b-an1), R 101 is a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent.

[0500] Cyclic group which may have a substituent:

[0501] This cyclic group is preferably a cyclic hydrocarbon group, and this cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. In addition, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0502] R 101 The aromatic hydrocarbon group in is a hydrocarbon group having an aromatic ring. The carbon number of this aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. Among them, the carbon number does not include the carbon number in the substituent.

[0503] As the aromatic ring possessed by the aromatic hydrocarbon group in R 101 Specific examples include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocycle obtained by substituting a part of the carbon atoms constituting these aromatic rings with a heteroatom. As the heteroatom in the aromatic heterocycle, examples include an oxygen atom, a sulfur atom, a nitrogen atom, etc.

[0504] As R 101The aromatic hydrocarbon group herein, specifically, examples thereof include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group obtained by substituting one hydrogen atom of the aromatic ring with an alkylene group (for example, arylalkyl such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The carbon number of the alkylene group (the alkyl chain in the arylalkyl) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0505] R 101 The cyclic aliphatic hydrocarbon group herein may be exemplified by an aliphatic hydrocarbon group containing a ring in its structure.

[0506] Examples of the aliphatic hydrocarbon group containing a ring in its structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group obtained by bonding the terminal of an alicyclic hydrocarbon group to a straight-chain or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed between a straight-chain or branched aliphatic hydrocarbon group, etc.

[0507] The carbon number of the alicyclic hydrocarbon group is preferably 3 to 20, more preferably 3 to 12.

[0508] The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred, and specifically, cyclopentane, cyclohexane, etc. may be exemplified. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, a polycycloalkane having 7 to 30 carbon atoms is preferred. Among them, as the polycycloalkane, a polycyclic alicyclic hydrocarbon having a crosslinked ring-type polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. is more preferred; a cyclic group having a steroid skeleton and other polycyclic alicyclic hydrocarbons having a fused ring-type polycyclic skeleton.

[0509] Among them, as R 101 The cyclic aliphatic hydrocarbon group herein is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane, more preferably a group obtained by removing one hydrogen atom from a polycycloalkane, particularly preferably an adamantyl group, a norbornyl group, and most preferably an adamantyl group.

[0510] The carbon number of the straight-chain aliphatic hydrocarbon group that can be bonded to the alicyclic hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 4, and most preferably 1 to 3. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specifically, examples thereof include methylene [-CH2-], ethylene [-(CH2)2-], propylene [-(CH2)3-], butylene [-(CH2)4-], pentylene [-(CH2)5-], etc.

[0511] The number of carbon atoms of the branched aliphatic hydrocarbon group that can be bonded to the alicyclic hydrocarbon group is preferably 2 to 10, more preferably 3 to 6, still more preferably 3 or 4, and most preferably 3. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylene methines such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylene ethylenes such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkylene propylenes such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkylene butylenes such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2- and other alkylene alkylenes. As the alkyl group in the alkylene alkyl group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0512] In addition, the cyclic hydrocarbon group in R 101 may contain a heteroatom such as a heterocycle. Specifically, examples include a lactone ring-containing group represented by the general formula (a2-r-1) to (a2-r-7), a -SO2-ring-containing group represented by the general formula (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16). In the formula, * represents a chemical bond bonded to Y in the formula (b-an1). 101 bonded chemical bond.

[0513] [Chemical formula 54]

[0514]

[0515] As a substituent in the cyclic group of R 101 , for example, alkyl, alkoxy, halogen atom, haloalkyl, hydroxyl, carbonyl, nitro, etc. can be cited.

[0516] The alkyl group as a substituent preferably has 1 to 5 carbon atoms, and most preferably is methyl, ethyl, propyl, n-butyl, or tert-butyl.

[0517] The alkoxy group as a substituent preferably has 1 to 5 carbon atoms, more preferably methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, or tert-butoxy, and most preferably methoxy or ethoxy.

[0518] The halogen atom as a substituent is preferably a fluorine atom.

[0519] The haloalkyl group as a substituent may be exemplified by a group in which part or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, tert-butyl, etc., are substituted by the halogen atom.

[0520] The carbonyl group as a substituent is a group that substitutes the methylene group (-CH2-) constituting the cyclic hydrocarbon group.

[0521] R 101 The cyclic hydrocarbon group in may be a condensed ring type group containing a condensed ring formed by condensation of an aliphatic hydrocarbon ring and an aromatic ring. As the condensed ring, for example, a condensed ring formed by condensation of one or more aromatic rings and a polycyclic alkane having a polycyclic skeleton of crosslinked ring type, etc. may be exemplified. As a specific example of the polycyclic alkane of the crosslinked ring type, bicyclo[2.2.1]heptane (norbornane), bicyclo[2.2.2]octane and other bicyclic alkanes may be exemplified. As the condensed ring type group, a group containing a condensed ring formed by condensation of two or three aromatic rings and a bicyclic alkane is preferred, and a group containing a condensed ring formed by condensation of two or three aromatic rings and bicyclo[2.2.2]octane is more preferred. As the specific example of the condensed ring type group in R 101 The group represented by the following formula (r-br-1) to (r-br-2) may be exemplified. In the formula, * represents a chemical bond bonded to Y in the formula (b-an1). 101 Bonding chemical bond.

[0522] [Chemical formula 55]

[0523]

[0524] As R 101 The substituents that the condensed ring type group in may have, for example, alkyl group, alkoxy group, halogen atom, haloalkyl group, hydroxyl group, carbonyl group, nitro group, aromatic hydrocarbon group, alicyclic hydrocarbon group, etc. may be exemplified.

[0525] As the alkyl group, alkoxy group, halogen atom, haloalkyl group as the substituent of the condensed ring type group, the same groups as those exemplified as the substituent of the cyclic group in the above R 101 May be exemplified.

[0526] As the aromatic hydrocarbon group as the substituent of the condensed ring type group, a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group obtained by substituting one hydrogen atom of the aromatic ring with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.), heterocyclic type groups represented by the above formula (r-hr-1) to (r-hr-6), respectively, etc. may be exemplified.

[0527] Examples of the alicyclic hydrocarbon group as a substituent of the condensed ring group include groups obtained by removing one hydrogen atom from monocyclic alkanes such as cyclopentane and cyclohexane; groups obtained by removing one hydrogen atom from polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; lactone ring-containing groups represented by the general formulas (a2-r-1) to (a2-r-7), respectively; -SO2-ring-containing groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively; heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16), respectively, and the like.

[0528] A chain alkyl group which may have a substituent:

[0529] As R 101 The chain alkyl group may be either linear or branched.

[0530] As the linear alkyl group, the number of carbon atoms is preferably 1 to 20, more preferably 1 to 15, and most preferably 1 to 10.

[0531] As the branched alkyl group, the number of carbon atoms is preferably 3 to 20, more preferably 3 to 15, and most preferably 3 to 10. Specifically, for example, 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, etc. can be cited.

[0532] A chain alkenyl group which may have a substituent:

[0533] As R 101 The chain alkenyl group may be either linear or branched, the number of carbon atoms is preferably 2 to 10, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. As the linear alkenyl group, for example, vinyl, 1-propenyl, 2-propenyl (allyl), butynyl, etc. can be cited. As the branched alkenyl group, for example, 1-methylvinyl, 1-methylpropenyl, 2-methylpropenyl, etc. can be cited.

[0534] Among the above, as the chain alkenyl group, a linear alkenyl group is preferred, more preferably vinyl or propenyl, and particularly preferably vinyl.

[0535] As the substituent in the chain alkyl group or chain alkenyl group of R 101 For example, alkoxy, halogen atom, haloalkyl, hydroxyl, carbonyl, nitro, amino, and cyclic groups in the above R 101 can be cited.

[0536] Among the above, R 101Preferably a cyclic group which may have a substituent, more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, preferably a group obtained by removing one or more hydrogen atoms from phenyl, naphthyl, polycyclic alkane; lactone ring-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), respectively; -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively, etc.

[0537] In formula (b-an1), Y 101 is a single bond or a divalent linking group containing an oxygen atom.

[0538] When Y 101 is a divalent linking group containing an oxygen atom, this Y 101 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, etc.

[0539] Examples of the divalent linking group containing an oxygen atom include non-hydrocarbon oxygen atom-containing linking groups such as an oxygen atom (ether bond: -O-), ester bond (-C(=O)-O-), oxycarbonyl (-O-C(=O)-), amide bond (-C(=O)-NH-), carbonyl (-C(=O)-), carbonate bond (-O-C(=O)-O-); combinations of such non-hydrocarbon oxygen atom-containing linking groups and alkylene groups, etc. In this combination, a sulfonyl group (-SO2-) may be further linked. Examples of the divalent linking group containing an oxygen atom include linking groups represented by the following general formulas (y-al-1) to (y-al-7), respectively.

[0540] [Chemical formula 56]

[0541]

[0542] [In the formula, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]

[0543] The divalent saturated hydrocarbon group in V' 102 is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and further preferably an alkylene group having 1 to 5 carbon atoms.

[0544] As the alkylene group in V' 101 and V' 102 it may be a linear alkylene group or a branched alkylene group, preferably a linear alkylene group.

[0545] As the alkylene group in V' 101 and V' 102The alkylene group therein, specifically, examples thereof include methylene [-CH2-]; alkylmethylenes such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene [-CH2CH2-]; alkylethylenes such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-; propylene (n-propylene) [-CH2CH2CH2-]; alkylpropylenes such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; butylene [-CH2CH2CH2CH2-]; alkylbutylenes such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-; pentylene [-CH2CH2CH2CH2CH2-] and the like.

[0546] In addition, V’ 101 or V’ 102 In a part of the methylene groups in the alkylene group in, some of the methylene groups can be replaced by a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group) of Ra’ in the formula (a1-r-1). 3 More preferably, it is cyclohexylene, 1,5-adamantylene or 2,6-adamantylene.

[0547] As Y 101 , preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably the linking groups represented by the above formulas (y-al-1) to (y-al-5) respectively.

[0548] In the formula (b1-an1), V 101 is a single bond, an alkylene group or a fluoroalkylene group. The alkylene group and fluoroalkylene group in V 101 preferably have 1 to 4 carbon atoms. As the fluoroalkylene group in V 101 , examples thereof include a group obtained by replacing a part or all of the hydrogen atoms of the alkylene group in V 101 with fluorine atoms. Among them, V 101 is preferably a single bond or a fluoroalkylene group having 1 to 4 carbon atoms.

[0549] In the formula (b1-an1), R 102 is a fluorine atom or a fluoroalkyl group having 1 to 5 carbon atoms. R 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

[0550] As a specific example of the anionic moiety represented by the formula (b1 - an1), for example, when Y 101 is a single bond, fluoroalkylsulfonate anions such as trifluoromethanesulfonate anion or perfluorobutanesulfonate anion can be exemplified; when Y 101 is a divalent linking group containing an oxygen atom, anions represented by any one of the following formulas (an - 1) to (an - 3) can be exemplified.

[0551] [Chemical formula 57]

[0552]

[0553] [In the formula, R” 101 is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by the above chemical formulas (r - hr - 1) to (r - hr - 6) respectively, a condensed ring group represented by the formula (r - br - 1) or (r - br - 2), or a chain - like alkyl group which may have a substituent. R” 102 is an aliphatic cyclic group which may have a substituent, a condensed ring group represented by the formula (r - br - 1) or (r - br - 2), a lactone - containing cyclic group represented by the general formulas (a2 - r - 1), (a2 - r - 3) to (a2 - r - 7) respectively, or a - SO2 - containing cyclic group represented by the general formulas (a5 - r - 1) to (a5 - r - 4) respectively. R” 103 is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain - like alkenyl group which may have a substituent. V” 101 is a single bond, an alkylene group having 1 to 4 carbon atoms or a fluoroalkylene group having 1 to 4 carbon atoms. R 102 is a fluorine atom or a fluoroalkyl group having 1 to 5 carbon atoms. v” are each independently an integer of 0 to 3, q” are each independently an integer of 0 to 20, and n” is 0 or 1.]

[0554] R” 101 、R” 102 and R” 103 The aliphatic cyclic group which may have a substituent of R” 101 is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in R 101 in the formula (b1 - an1). As the substituent, a group the same as the substituent which can substitute the cyclic aliphatic hydrocarbon group in R 101 in the formula (b1 - an1) can be exemplified.

[0555] R” 103 The aromatic cyclic group which may have a substituent in R 101The groups exemplified by the aromatic hydrocarbon group in the cyclic hydrocarbon group. As the said substituent, the same groups as the substituents which can substitute the aromatic hydrocarbon group in the said formula (b1-an1) can be cited. 101 The same groups as the substituents which can substitute the aromatic hydrocarbon group in 101 .

[0556] R” 101 The chain-like alkyl group which may have a substituent in 101 is preferably the group exemplified as R in the said formula (b1-an1). 101 The group exemplified by the chain-like alkyl group in 101 .

[0557] R” 103 The chain-like alkenyl group which may have a substituent in 103 is preferably the group exemplified as R in the said formula (b1-an1). 101 The group exemplified by the chain-like alkenyl group in 101 .

[0558] · An anion represented by the formula (b1-an2)

[0559] In the formula (b1-an2), R 104 、R 105 are each independently a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and the same groups as R in the formula (b1-an1) can be cited respectively. Among them, R 101 、R 104 、R 105 may bond to each other to form a ring.

[0560] R 104 、R 105 are preferably a chain-like alkyl group which may have a substituent, more preferably a straight-chain or branched-chain alkyl group, or a straight-chain or branched-chain fluoroalkyl group.

[0561] The carbon number of the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 7, and further preferably 1 to 3. For reasons such as good solubility in the resist solvent, the smaller the carbon number of the chain-like alkyl group of R 104 、R 105 within the above carbon number range, the more preferable. In addition, in the chain-like alkyl group of R 104 、R 105 , the more the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid strength and the higher the transparency to high-energy light or electron rays of 250 nm or less, and thus it is preferable. The proportion of fluorine atoms in the chain-like alkyl group, that is, the fluorination rate is preferably 70 to 100%, further preferably 90 to 100%, and most preferably a perfluoroalkyl group obtained by substituting all hydrogen atoms with fluorine atoms.

[0562] In the formula (b-an2), V 102 、V 103Each is independently a single bond, an alkylene group, or a fluoroalkylene group, and examples of the groups that can be separately cited are the same as those of V in formula (b1-an1). 101 The same groups.

[0563] In formula (b1-an2), L 101 and L 102 are each independently a single bond or an oxygen atom.

[0564] ·An anion represented by formula (b1-an3)

[0565] In formula (b1-an3), R 106 to R 108 are each independently a cyclic group that may have a substituent, a linear alkyl group that may have a substituent, or a linear alkenyl group that may have a substituent, and examples of the groups that can be separately cited are the same as those of R in formula (b1-an1). 101 The same groups.

[0566] In formula (b1-an3), L 103 to L 105 are each independently a single bond, -CO-, or -SO2-.

[0567] Among the above, as the anion part of the (B1) component, an anion represented by formula (b1-an1) is preferred. Among them, an anion represented by any one of the above formulas (an-1) to (an-3) is more preferred, an anion represented by any one of the above formulas (an-1) or (an-2) is further preferred, and an anion represented by the above formula (an-2) is particularly preferred.

[0568] Among them, the (B1) component is preferably a compound represented by the following general formula (b1-1).

[0569] [Chemical formula 58]

[0570]

[0571] [In the formula, Yb 011 represents a divalent linking group represented by any one of the above formulas (ca-y1-1) to (ca-y1-5). Rb 011 represents a cyclic alkyl group that may have a substituent. Rb 04 to Rb 06 each independently represent an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group, or a nitro group. n b04 represents an integer of 0 to 4, and n b05 to n b06 each independently represent an integer of 0 to 5. R 101 is a cyclic group that may have a substituent, a linear alkyl group that may have a substituent, or a linear alkenyl group that may have a substituent. R 102is a fluoroalkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 is a single bond or an oxygen atom. ]

[0572] Specific examples of the component (B1) are shown below, but are not limited thereto.

[0573] [Chemical formula 59]

[0574]

[0575] In the resist composition of the present embodiment, the component (B1) may be used alone in one kind or two or more kinds may be used in combination.

[0576] In the resist composition of the present embodiment, the content of the component (B1) is preferably less than 50 parts by mass, more preferably 1 to 40 parts by mass, and still more preferably 5 to 25 parts by mass with respect to 100 parts by mass of the component (A). By making the content of the component (B1) within the above preferred range, generation of defects can be more suppressed, and the effects of the present invention can be more easily obtained.

[0577] · Regarding the component (B2)

[0578] The resist composition of the present embodiment may contain an acid generator component other than the component (B1) (hereinafter referred to as the "component (B2)") within a range not impairing the effects of the present invention.

[0579] The component (B2) is not particularly limited, and an acid generator proposed so far as an acid generator for a chemically amplified resist composition can be used.

[0580] Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, sulfonic acid oxime ester acid generators; diazomethane acid generators such as bis(alkyl or arylsulfonyl)diazomethanes and poly(bisulfonyl)diazomethanes; and various acid generators such as nitrobenzyl sulfonate acid generators, iminosulfonate acid generators, and disulfone acid generators.

[0581] <Acid diffusion control agent component (D)>

[0582] The resist composition of the present embodiment contains an acid diffusion control agent component (D) (component (D)) in addition to the component (A) and the component (B). The component (D) is a component that functions as a quencher (acid diffusion control agent) for capturing acid generated by exposure in the resist composition. In the present embodiment, the component (D) contains a compound (D1) represented by the following general formula (d1) (hereinafter, sometimes referred to as the "(D1) component").

[0583] · Regarding the component (D1)

[0584] (Component (D1) is a compound represented by the following general formula (d1). When component (D1) is used together with component (A1) having the above structural unit (a0) and component (B1), lithography characteristics such as sensitivity and defect improvement can be enhanced.)

[0585] [Chemical formula 60]

[0586]

[0587] [In the formula, Rd 01 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. Among them, a fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in the formula. m is an integer of 1 or more, and M m+ are each independently an m-valent organic cation.]

[0588] {Anionic part}

[0589] In formula (d1), Rd 01 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent.)

[0590] Cyclic group which may have a substituent:

[0591] The cyclic group is preferably a cyclic hydrocarbon group. The cyclic hydrocarbon group may be an aromatic hydrocarbon group or a cyclic aliphatic hydrocarbon group.)

[0592] The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. Among them, the carbon atoms in the carbon number do not include the carbon atoms in the substituent.)

[0593] Specific examples of the aromatic ring of the aromatic hydrocarbon group include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocycle obtained by substituting a part of the carbon atoms of these aromatic rings with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom, etc.)

[0594] Examples of the aromatic hydrocarbon group include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group obtained by substituting one hydrogen atom of the aromatic ring with an alkylene group (for example, arylalkyl such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The carbon number of the alkylene group (alkyl chain in the arylalkyl) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.)

[0595] The cyclic aliphatic hydrocarbon group is an aliphatic hydrocarbon group containing a ring in its structure. Examples of the cyclic aliphatic hydrocarbon group include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group obtained by bonding the terminal of an alicyclic hydrocarbon group to a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed between a linear or branched aliphatic hydrocarbon group, and the like.

[0596] The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred, and specific examples include cyclopentane, cyclohexane, and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferred. As the polycycloalkane, a polycycloalkane having 7 to 30 carbon atoms is preferred. Specific examples of the polycycloalkane include polycycloalkanes having a cross-linked ring type polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a fused ring type such as a cyclic group having a steroid skeleton.

[0597] Among them, as the cyclic aliphatic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane is preferred, a group obtained by removing one hydrogen atom from a polycycloalkane is more preferred, an adamantyl group or a norbornyl group is particularly preferred, and an adamantyl group is most preferred.

[0598] The linear or branched aliphatic hydrocarbon group that can be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms.

[0599] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. As the branched aliphatic hydrocarbon group, a branched alkylene group having 2 to 10 carbon atoms is preferred. Specific examples of the linear or branched alkylene group include the same groups as those exemplified for Va in the general formula (a0-1). 01 in the formula.

[0600] As Rd 01 The cyclic hydrocarbon group of can contain a hetero atom like a heterocycle. Specifically, examples include a lactone ring-containing group represented by the general formulas (a2-r-1) to (a2-r-7), a -SO2-ring-containing group represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16).

[0601] Examples of the substituents that the cyclic group may have include alkyl groups, alkoxy groups, halogen atoms, haloalkyl groups, hydroxyl groups, carbonyl groups, nitro groups, etc.

[0602] As the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferred, and methyl, ethyl, propyl, n-butyl or tert-butyl is more preferred.

[0603] As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy or tert-butoxy is more preferred, and methoxy or ethoxy is further preferred.

[0604] The halogen atom as a substituent is preferably a fluorine atom.

[0605] As the haloalkyl group as a substituent, a group in which part or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms are substituted by the halogen atom can be exemplified.

[0606] The carbonyl group as a substituent is a group that substitutes the methylene group (-CH2-) constituting the cyclic hydrocarbon group.

[0607] The chain alkyl group that may have a substituent:

[0608] The chain alkyl group may be linear or branched.

[0609] As the linear alkyl group, 1 to 20 carbon atoms are preferred, 1 to 15 carbon atoms are more preferred, and 1 to 10 carbon atoms are further preferred.

[0610] As the branched alkyl group, 3 to 20 carbon atoms are preferred, 3 to 15 carbon atoms are more preferred, and 3 to 10 carbon atoms are further preferred. Specifically, for example, 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, etc. can be exemplified.

[0611] The chain alkenyl group that may have a substituent:

[0612] The chain alkenyl group may be linear or branched. The chain alkenyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, further preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms.

[0613] As the linear alkenyl group, vinyl, propenyl (allyl), butynyl, etc. can be exemplified. As the branched alkenyl group, for example, 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, 2-methylpropenyl, etc. can be exemplified.

[0614] Among them, as the chain-like alkenyl group, a linear alkenyl group is preferred, a vinyl group or a propenyl group is more preferred, and a vinyl group is further preferred.

[0615] Examples of the substituents that the chain-like alkyl group or chain-like alkenyl group may have include an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the cyclic groups exemplified as the above-mentioned Rd 01 and the like.

[0616] Among them, no fluorine atom is bonded to the carbon atom adjacent to the S atom in Rd 01 (fluorine-free substitution). Thus, the anion of the component (D1) becomes a moderately weak acid anion, and the quenching ability is improved.

[0617] As Rd 01 , in addition to the above, as the cyclic group that may have a substituent or the chain-like alkyl group that may have a substituent, a group having the same structure as the acid dissociable group represented by the formula (a1-r-2) can also be exemplified.

[0618] Among them, Rd 01 is preferably a cyclic group that may have a substituent, and more preferably a cyclic hydrocarbon group that may have a substituent. As Rd 01 , preferred specific examples include groups obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycyclic alkane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7) respectively; -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4) respectively, and the like.

[0619] As Rd 01 , it is preferably a chain-like alkyl group that may have a substituent or a cyclic aliphatic hydrocarbon group that may have a substituent. As the chain-like alkyl group, the number of carbon atoms is preferably 1 to 10, and more preferably 3 to 10. As the cyclic aliphatic hydrocarbon group, an alicyclic hydrocarbon group or a group obtained by bonding the terminal of an alicyclic hydrocarbon group to a linear or branched alkylene group having 1 to 5 carbon atoms is preferred. The alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent); a group obtained by removing one or more hydrogen atoms from camphor, etc.; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7) respectively. Among them, as the alicyclic hydrocarbon group, a group obtained by removing one hydrogen atom from adamantane or camphor or a lactone-containing cyclic group represented by the general formula (a2-r-7) is more preferred, and a group obtained by removing one hydrogen atom from camphor or a lactone-containing cyclic group represented by the general formula (a2-r-7) is further preferred.

[0620] The anionic part as the component (D1) is preferably an anion represented by the following general formula (d1-an).

[0621] [Chemical Formula 61]

[0622]

[0623] [In the formula, Ld 011 represents an alkylene group which may have a substituent. Among them, in Ld 011 , a fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in the formula. Yd 011 represents a single bond or a divalent linking group containing an oxygen atom. Rd 011 represents an alicyclic hydrocarbon group which may have a substituent.]

[0624] In the formula (d1-an), Ld 011 represents an alkylene group which may have a substituent. The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, still more preferably 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The alkylene group may be linear or branched. As specific examples of the linear or branched alkylene group, groups the same as those exemplified as the linear or branched alkylene group in Va 01 in the formula (a0-1) can be cited.

[0625] The alkylene group in Ld 011 may or may not have a substituent, and preferably does not have a substituent. As the substituent that the alkylene group in Ld 011 may have, for example, alkoxy, hydroxy, carbonyl, nitro, amino, etc. can be cited.

[0626] As the alkylene group in Ld 011 , a linear alkylene group having 1 to 5 carbon atoms is preferred, a linear alkylene group having 1 to 3 carbon atoms is more preferred, and methylene or ethylene is still more preferred.

[0627] In the formula (d1-an), Yd 011 represents a single bond or a divalent linking group containing an oxygen atom.

[0628] When Yd 011 is a divalent linking group containing an oxygen atom, Yd 011 may contain atoms other than oxygen atoms. As the atoms other than oxygen atoms, for example, carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, etc. can be cited.

[0629] As a divalent linking group containing an oxygen atom, examples include non-hydrocarbon linking groups containing an oxygen atom such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), a carbonate bond (-O-C(=O)-O-), etc.; combinations of the non-hydrocarbon linking groups containing an oxygen atom with an alkylene group, etc. In this combination, a sulfonyl group (-SO2-) may also be further linked. As the divalent linking group containing an oxygen atom, linking groups represented by the general formulas (y-al-1) to (y-al-7) can be exemplified respectively.

[0630] As Yd 011 , preferably a single bond, a divalent linking group containing an ester bond, or a divalent linking group containing an ether bond, more preferably a single bond, or linking groups represented by the formulas (y-al-1) to (y-al-5) respectively. Among them, as Yd 011 , preferably -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-.

[0631] In the formula (d1-an), Rd 011 represents an alicyclic hydrocarbon group which may have a substituent. The alicyclic hydrocarbon group in Rd 011 can be exemplified by the same groups as those exemplified for the alicyclic hydrocarbon group in Rd 01 .

[0632] The following shows preferred specific examples of the anionic part of the component (D1).

[0633] [Chemical formula 62]

[0634]

[0635] In the above examples, the anionic part in the component (D1) is preferably an anion represented by any one of the formulas (d1-an-1) to (d1-an-8), and more preferably an anion represented by any one of the formula (d1-an-1) and the formulas (d1-an-5) to (d1-an-8).

[0636] {Cationic part}

[0637] In the formula (d1), M m+ represents an m-valent organic cation. m is an integer of 1 or more. The organic cation is preferably a sulfonium cation or an iodonium cation.

[0638] As the preferred cationic part of the component (D1) ((M’ m+ ) 1 / m), organic cations represented by the following general formulas (ca-1) to (ca-5) can be exemplified.

[0639] [Chemical formula 63]

[0640]

[0641] [In the formula, R 201 ~R 207 and R 211 ~R 212 each independently represent an aryl group, an alkyl group or an alkenyl group which may have a substituent. R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 may be bonded to each other to form a ring together with the sulfur atom in the formula. R 208 ~R 209 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO2-containing cyclic group which may have a substituent. L 201 represents -C(=O)- or -C(=O)-O-. Y 201 each independently represent an arylene group, an alkylene group or an alkenylene group. x is 1 or 2. W 201 represents an (x + 1)-valent linking group. ]

[0642] In the above general formulas (ca-1) to (ca-5), as R 201 ~R 207 and R 211 ~R 212 in the aryl group, unsubstituted aryl groups having 6 to 20 carbon atoms can be exemplified, preferably phenyl group and naphthyl group.

[0643] As R 201 ~R 207 and R 211 ~R 212 in the alkyl group, it is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms.

[0644] As R 201 ~R 207 and R 211 ~R 212 in the alkenyl group, it is preferably having 2 to 10 carbon atoms.

[0645] As R 201 ~R 207 and R 210 ~R 212Substituents that can be included are, for example, alkyl groups, halogen atoms, haloalkyl groups, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the following general formulas (ca-r-1) to (ca-r-7), etc.

[0646] [Chemical Formula 64]

[0647]

[0648] [In the formula, R’ 201 is independently a hydrogen atom, a cyclic group that may have a substituent, a linear alkyl group that may have a substituent, or a linear alkenyl group that may have a substituent.]

[0649] As the cyclic group, linear alkyl group, or linear alkenyl group that may have a substituent for R’ 201 groups the same as those exemplified for Rd 01 in the formula (d1) can be exemplified.

[0650] Among them, as R’ 201 , a cyclic group that may have a substituent is preferred, and a cyclic hydrocarbon group that may have a substituent is more preferred. More specifically, for example, a group obtained by removing one or more hydrogen atoms from phenyl, naphthyl, or polycyclic alkane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7) respectively; -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4) respectively, etc. are preferred.

[0651] In the above general formulas (ca-1) to (ca-4), when R 201 to R 203 , R 206 to R 207 , R 211 to R 212 are bonded to each other to form a ring together with the sulfur atom in the formula, they can be bonded via heteroatoms such as sulfur atoms, oxygen atoms, nitrogen atoms, carbonyl groups, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )- (where this R N is an alkyl group having 1 to 5 carbon atoms) and other functional groups. As the formed ring, a ring having 1 ring including the sulfur atom in its ring skeleton is preferably a three- to ten-membered ring, and particularly preferably a five- to seven-membered ring. Specific examples of the formed ring include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, phenoxathiin ring, tetrahydrothiophenium ring, tetrahydrothiopyranium ring, etc.

[0652] R 208 to R 209Each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In the case of R 208 ~R 209 being an alkyl group, they may be bonded to each other to form a ring.

[0653] R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO2-containing cyclic group which may have a substituent.

[0654] As the aryl group in R 210 , an unsubstituted aryl group having 6 to 20 carbon atoms can be exemplified, preferably a phenyl group or a naphthyl group.

[0655] As the alkyl group in R 210 , a linear or cyclic alkyl group having 1 to 30 carbon atoms is preferred.

[0656] As the alkenyl group in R 210 , preferably having 2 to 10 carbon atoms.

[0657] As the -SO2-containing cyclic group which may have a substituent in R 210 , preferably a "-SO2-containing polycyclic group", more preferably a group represented by the general formula (a5-r-1).

[0658] Y 201 Each independently represents an arylene group, an alkylene group or an alkenylene group.

[0659] The arylene group in Y 201 can be exemplified by a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group in R 101 in the above formula (b1-an1).

[0660] The alkylene group and alkenylene group in Y 201 can be exemplified by a group obtained by removing one hydrogen atom from the groups exemplified as the linear alkyl group and linear alkenyl group in R 101 in the above formula (b1-an1).

[0661] In the formula (ca-4), x is 1 or 2.

[0662] W 201 is a linking group having a valence of (x + 1), that is, a divalent or trivalent linking group.

[0663] As the divalent linking group in W 201 , a divalent hydrocarbon group which may have a substituent is preferred, and a divalent hydrocarbon group which may have a substituent and is the same as Ya 21 in the above general formula (a2-1) can be exemplified. W 201The divalent linking group in [it] can be any of linear, branched, or cyclic, preferably cyclic. Among them, a group obtained by combining two carbonyl groups at both ends of an arylene group is preferred. As the arylene group, a phenylene group, a naphthylene group, etc. can be exemplified, and a phenylene group is particularly preferred.

[0664] As W 201 the trivalent linking group in [it], examples include a group obtained by removing one hydrogen atom from the divalent linking group in the said W 201 , a group obtained by bonding the divalent linking group to the divalent linking group again, etc. As W 201 the trivalent linking group in [it], a group obtained by bonding two carbonyl groups to an arylene group is preferred.

[0665] As the preferred cation represented by the formula (ca-1), specifically, the following cations can be exemplified.

[0666] [Chemical formula 65]

[0667]

[0668] [Chemical formula 66]

[0669]

[0670] [Chemical formula 67]

[0671]

[0672] [In the formula, g1, g2, and g3 represent the number of repetitions, g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20.]

[0673] [Chemical formula 68]

[0674]

[0675] [Chemical formula 69]

[0676]

[0677] [Chemical formula 70]

[0678]

[0679] [Chemical formula 71]

[0680]

[0681] [In the formula, R” 201 is a hydrogen atom or a substituent. As this substituent, as the said R 201 ~R 207 and R 210 ~R212 The groups exemplified as the substituents that can be possessed are the same.

[0682] [Chemical formula 72]

[0683]

[0684] As a preferred cation represented by the formula (ca-2), specifically, a diphenyliodonium cation, a bis(4-tert-butylphenyl)iodonium cation, etc. can be exemplified.

[0685] As a preferred cation represented by the formula (ca-3), specifically, cations represented by the following formulas (ca-3-1) to (ca-3-6) can be exemplified.

[0686] [Chemical formula 73]

[0687]

[0688] As a preferred cation represented by the formula (ca-4), specifically, cations represented by the following formulas (ca-4-1) to (ca-4-2) can be exemplified.

[0689] [Chemical formula 74]

[0690]

[0691] As a preferred cation represented by the formula (ca-5), specifically, cations represented by the following general formulas (ca-5-1) to (ca-5-3) can be exemplified.

[0692] [Chemical formula 75]

[0693]

[0694] Among the above, the cation moiety in the component (D1) is preferably a cation represented by the general formula (ca-1).

[0695] As the component (D1), a compound represented by the following general formula (d1-1) is preferred.

[0696] [Chemical formula 76]

[0697]

[0698] [In the formula, Rd 01 represents a cyclic group that may have a substituent, a chain-like alkyl group that may have a substituent, or a chain-like alkenyl group that may have a substituent. Among them, a fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in the formula. R 201 ~R 203 each independently represents an aryl group, an alkyl group, or an alkenyl group that may have a substituent. R201 ~R 203 can be bonded to each other to form a ring together with the sulfur atom in the formula.]

[0699] Specific examples of the component (D1) are listed below, but are not limited thereto.

[0700] [Chemical Formula 77]

[0701]

[0702] In the resist composition of the present embodiment, the component (D1) may be used alone in one kind or two or more kinds may be used in combination.

[0703] In the resist composition of the present embodiment, the content of the component (D1) is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, still more preferably 0.5 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the component (A).

[0704] By making the content of the component (D1) within the above-mentioned preferred range, the sensitivity is further improved, and the effects of the present invention can be more easily obtained.

[0705] In the resist composition of the present embodiment, the mixing ratio (mass ratio) of the component (B1) to the component (D1) is preferably (B1) component / (D1) component (mass ratio) = 3 to 30, more preferably 5 to 25, and still more preferably 8 to 25.

[0706] ·Regarding the component (D2)

[0707] The resist composition of the present embodiment may contain an acid diffusion control agent component other than the component (D1) (hereinafter referred to as the “component (D2)”) within a range not impairing the effects of the present invention.

[0708] The component (D2) is not particularly limited, and an acid diffusion control agent proposed as an acid diffusion control agent for a chemically amplified resist composition can be used.

[0709] Examples of the component (D2) include a photodegradable base that loses acid diffusion control by exposure decomposition (excluding components belonging to the component (D1)) and a nitrogen-containing organic compound that does not belong to the photodegradable base.

[0710] <Optional Component>

[0711] The resist composition of the present embodiment may further contain components other than the above-mentioned components (A), (B), and (D) (optional components). Examples of the optional components include the following components (E), (F), and (S).

[0712] "Compound (E) selected from the group consisting of organic carboxylic acids and oxygen-containing acids of phosphorus and their derivatives"

[0713] For the purpose of preventing sensitivity deterioration or improving resist pattern shape, standing durability, etc., the resist composition of the present embodiment can contain at least one compound (E) (hereinafter referred to as "(E) component") selected from the group consisting of organic carboxylic acids and oxygen-containing acids of phosphorus and their derivatives as an optional component.

[0714] As the organic carboxylic acid, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc. are preferable, for example.

[0715] As the oxygen-containing acid of phosphorus, phosphoric acid, phosphonic acid, hypophosphorous acid, etc. can be exemplified, and among these, phosphonic acid is particularly preferable.

[0716] As derivatives of the oxygen-containing acid of phosphorus, for example, esters obtained by substituting a hydrogen atom of the above oxygen-containing acid with a hydrocarbon group can be exemplified. As the hydrocarbon group, an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 15 carbon atoms, etc. can be exemplified.

[0717] As derivatives of phosphoric acid, phosphoric acid esters such as di-n-butyl phosphate, diphenyl phosphate, etc. can be exemplified.

[0718] As derivatives of phosphonic acid, phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, dibenzyl phosphonate, etc. can be exemplified.

[0719] As derivatives of hypophosphorous acid, hypophosphite esters or phenylhypophosphorous acid, etc. can be exemplified.

[0720] In the resist composition of the present embodiment, the (E) component can be used alone or in combination of two or more.

[0721] When the resist composition contains the (E) component, the content of the (E) component is usually used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the (A) component.

[0722] "Fluorine additive component (F)"

[0723] In order to impart water repellency to the resist film or to improve lithography characteristics, the resist composition of the present embodiment can contain a fluorine additive component (hereinafter referred to as "(F) component").

[0724] As the (F) component, for example, fluorine-containing polymer compounds described in JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226 can be used.

[0725] As the component (F), more specifically, polymers having a structural unit (f1) represented by the following general formula (f1-1) can be exemplified. As this polymer, a polymer (homopolymer) composed only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1); a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1) are preferred. Here, as the structural unit (a1) copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate and a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate are preferred.

[0726] [Chemical formula 78]

[0727]

[0728] [In the formula, R is the same as above, Rf 102 and Rf 103 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a haloalkyl group having 1 to 5 carbon atoms, and Rf 102 and Rf 103 may be the same or different. nf 1 is an integer from 0 to 5, and Rf 101 is an organic group containing a fluorine atom.]

[0729] In the formula (f1-1), R bonded to the carbon atom at the α-position is the same as above. As R, a hydrogen atom or a methyl group is preferred.

[0730] In the formula (f1-1), as the halogen atom of Rf 102 and Rf 103 , fluorine atom, chlorine atom, bromine atom, iodine atom, etc. can be exemplified, and a fluorine atom is particularly preferred. As the alkyl group having 1 to 5 carbon atoms of Rf 102 and Rf 103 , the same groups as the alkyl group having 1 to 5 carbon atoms of R above can be exemplified, and a methyl group or an ethyl group is preferred. As the haloalkyl group having 1 to 5 carbon atoms of Rf 102 and Rf 103 , specifically, a group obtained by substituting part or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms with a halogen atom can be exemplified. As this halogen atom, fluorine atom, chlorine atom, bromine atom, iodine atom, etc. can be exemplified, and a fluorine atom is particularly preferred. Among them, as Rf 102 and Rf 103 , a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms is preferred, and a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group is preferred.

[0731] In formula (f1-1), nf 1 is an integer from 0 to 5, preferably an integer from 0 to 3, and more preferably 1 or 2.

[0732] In formula (f1-1), Rf 101 is an organic group containing a fluorine atom, preferably a hydrocarbon group containing a fluorine atom.

[0733] As the hydrocarbon group containing a fluorine atom, it can be any of linear, branched or cyclic, preferably having 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms.

[0734] In addition, in the hydrocarbon group containing a fluorine atom, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferably 60% or more of the hydrogen atoms are fluorinated from the viewpoint of improving the hydrophobicity of the resist film during immersion exposure.

[0735] Among them, as Rf 101 , more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, particularly preferably trifluoromethyl, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, -CH2-CH2-CF2-CF2-CF2-CF3.

[0736] The weight average molecular weight (Mw) of the component (F) (based on polystyrene conversion standard by gel permeation chromatography) is preferably 1000 to 50000, more preferably 5000 to 40000, and most preferably 10000 to 30000. If it is below the upper limit value of this range, it has sufficient solubility in the resist solvent for use as a resist. If it is above the lower limit value of this range, the water repellency of the resist film is good.

[0737] The molecular weight distribution coefficient (Mw / Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0738] In the resist composition of this embodiment, the component (F) can be used alone or in combination of two or more.

[0739] When the resist composition contains the component (F), the content of the component (F) is usually used in a proportion of 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

[0740] 《Organic solvent component (S)》

[0741] The resist composition of this embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as the "(S) component").

[0742] As the (S) component, any component can be used as long as it can dissolve each of the components used to form a homogeneous solution, and any component can be appropriately selected from substances known as solvents for conventional chemically amplified resist compositions for use.

[0743] For example, as the (S) component, lactones such as γ-butyrolactone can be cited; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl n-pentyl ketone, methyl isoamyl ketone, and 2-heptanone; polyols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, monoalkyl ethers or monophenyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, or monobutyl ether of the above polyols or compounds having an ester bond, and derivatives of polyols such as compounds having an ether bond [among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, methyl tolyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, cumene, toluene, xylene, cymene, and mesitylene; dimethyl sulfoxide (DMSO), etc.

[0744] In the resist composition of this embodiment, the (S) component can be used alone as one kind, or as a mixed solvent of two or more kinds. Among them, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0745] In addition, as the (S) component, a mixed solvent obtained by mixing PGMEA with a polar solvent is also preferred. Its blending ratio (mass ratio) can be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, etc., and is preferably set in the range of 1:9 to 9:1, more preferably in the range of 2:8 to 8:2.

[0746] More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. In addition, when PGME is blended as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and further preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred.

[0747] In addition, as the (S) component, it is further preferably a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone. In this case, as the mixing ratio, the mass ratio of the former to the latter is preferably set to 70:30 to 95:5.

[0748] The amount of the (S) component used is not particularly limited and is appropriately set according to the coating film thickness at a concentration capable of being coated on a substrate or the like. Generally, the (S) component is used in such a manner that the solid component concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0749] In the resist composition of the present embodiment, additives having miscibility can be further appropriately added and contained as desired, such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like.

[0750] The resist composition of the present embodiment may also remove impurities and the like using a polyimide porous membrane, a polyamideimide porous membrane, etc. after dissolving the above-mentioned resist material in the (S) component. For example, a filter composed of a polyimide porous membrane, a filter composed of a polyamideimide porous membrane, a filter composed of a polyimide porous membrane and a polyamideimide porous membrane, etc. can be used for filtering the resist composition. As the polyimide porous membrane and the polyamideimide porous membrane, for example, the porous membranes described in Japanese Unexamined Patent Application Publication No. 2016-155121 can be exemplified.

[0751] The resist composition of the present embodiment described above contains a combination of an (A1) component having a structural unit (a0) represented by the general formula (a0-1), a (B1) component represented by the general formula (b1), and a (D1) component represented by the general formula (d1).

[0752] In conventional resist compositions, an improvement in sensitivity and a defect improvement are in a trade-off relationship, and it is difficult to obtain a resist composition having high sensitivity and a small number of defects. Furthermore, it is difficult to improve sensitivity and defects without deteriorating lithography characteristics such as CDU.

[0753] In contrast, the resist composition of the present embodiment contains a combination of an (A1) component, a (B1) component, and a (D1) component, thereby enabling high-sensitivity conversion and a reduction in the number of defects while maintaining lithography characteristics such as CDU. The reason is not yet clear, but it is speculated as follows.

[0754] (Component (A1)) improves its solubility in a developer (especially an alkaline developer) by having a structural unit (a0). On the other hand, since component (B1) has a relatively large structure, its solubility in an organic solvent is improved. Thus, it is considered that by incorporating component (A1) and component (B1) into the resist composition, high solubility can be achieved in both the developer and the organic solvent, which helps to improve defects. In addition, component (D1) controls acid diffusion as a quencher in the unexposed area. On the other hand, in the exposed area, it decomposes, and its decomposition products can contribute to the deprotection of the acid dissociable group of component (A). Thus, it is considered that the sensitivity is improved. Therefore, by using component (A1), component (B1) and component (D1) in combination, high sensitivity and reduction in the number of defects can be achieved while maintaining lithography characteristics such as CDU.

[0755] (Resist pattern forming method)

[0756] The resist pattern forming method of this embodiment is a method having a step of forming a resist film on a support using the resist composition of the above embodiment, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern.

[0757] As an embodiment of the above resist pattern forming method, for example, a resist pattern forming method carried out as described below can be cited.

[0758] First, on a support, the resist composition of the above embodiment is coated with a spinner or the like. For example, baking (pre-baking (PAB)) treatment is carried out at a temperature of 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds to form a resist film.

[0759] Next, for this resist film, for example, an exposure device such as an electron beam lithography device or an EUV exposure device is used. After selective exposure by exposure through a mask (mask pattern) having a specified pattern or by direct irradiation based on an electron beam without passing through a mask pattern, baking (post-exposure baking (PEB)) treatment is carried out at a temperature of 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds.

[0760] Next, the resist film is subjected to a development process. In the case of an alkaline development process, an alkaline developer is used for development. In the case of a solvent development process, a developer containing an organic solvent (organic developer) is used for development.

[0761] After the development process, a rinsing process is preferably performed. In the case of an alkaline development process, water rinsing with pure water is preferably used, and in the case of a solvent development process, a rinsing solution containing an organic solvent is preferably used.

[0762] In the case of a solvent development process, after the development process or the rinsing process, a process of removing the developer or the rinsing solution attached to the pattern by a supercritical fluid can be performed.

[0763] Drying is performed after the development process or the rinsing process. Additionally, a baking process (post-baking) can be performed after the above-mentioned development process as appropriate.

[0764] As described above, a resist pattern can be formed.

[0765] The support is not particularly limited, and conventionally known supports can be used. For example, substrates for electronic parts, supports on which a predetermined wiring pattern is formed, etc. can be cited. More specifically, substrates made of metals such as silicon wafers, copper, chromium, iron, and aluminum, or glass substrates can be cited. As materials for the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used.

[0766] In addition, as the support, a support provided with an inorganic and / or organic film on the substrate as described above can be used. As the inorganic film, an inorganic antireflection film (inorganic BARC) can be cited. As the organic film, an organic antireflection film (organic BARC), an organic film such as a lower organic film in the multilayer resist method, etc. can be cited.

[0767] Here, the multilayer resist method refers to a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the resist pattern formed on the upper resist film is used as a mask to pattern the lower organic film. It is considered that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be ensured by the lower organic film, so the resist film can be thinned, and a fine pattern with a high aspect ratio can be formed.

[0768] In the multilayer resist method, it is basically divided into a method using a two-layer structure of an upper resist film and a lower organic film (two-layer resist method); and a method using a multilayer structure of three layers or more in which one or more intermediate layers (such as a metal thin film) are provided between the upper resist film and the lower organic film (three-layer resist method).

[0769] The wavelength used in the 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, soft X-ray, etc. can be used. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV, more useful for ArF excimer laser, EB or EUV, and particularly useful for ArF excimer laser. That is, the resist pattern forming method of the present embodiment is a particularly useful method when the step of exposing the resist film includes the operation of exposing the resist film with an ArF excimer laser.

[0770] The exposure method of the resist film can be ordinary exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion lithography.

[0771] Liquid immersion lithography refers to an exposure method in which a solvent (immersion medium) having a refractive index larger than that of air is filled in advance between the resist film and the lens at the lowermost position of the exposure apparatus, and exposure (immersion exposure) is performed in this state.

[0772] As the immersion medium, a solvent having a refractive index larger than that of air and smaller than that of the resist film to be exposed is preferred. The refractive index of the above solvent is not particularly limited as long as it is within the above range.

[0773] As a solvent having a refractive index larger than that of air and smaller than that of the resist film, for example, water, fluorinated inert liquids, silicon-based solvents, hydrocarbon-based solvents, etc. can be cited.

[0774] As a specific example of the fluorinated inert liquid, liquids mainly composed of fluorinated compounds such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, C5H3F7, etc. can be cited. Liquids having a boiling point of 70 to 180 °C are preferred, and liquids having a boiling point of 80 to 160 °C are more preferred. If the fluorinated inert liquid has a boiling point within the above range, the medium used for immersion can be removed by a simple method after the exposure, so it is preferred.

[0775] As the fluorinated inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are replaced by fluorine atoms is particularly preferred. As the perfluoroalkyl compound, specifically, perfluoroalkyl ether compounds and perfluoroalkylamine compounds can be cited.

[0776] Furthermore, specifically, examples of the perfluoroalkyl ether compound include perfluoro(2-butyl-tetrahydrofuran) (boiling point 102°C), and examples of the perfluoroalkylamine compound include perfluorotributylamine (boiling point 174°C).

[0777] As the immersion liquid medium, water is preferably used from the viewpoints of cost, safety, environmental issues, versatility, etc.

[0778] As the alkaline developer used for development processing in the alkaline development process, for example, an aqueous solution of 0.1 to 10 mass% tetramethylammonium hydroxide (TMAH) can be cited.

[0779] As the organic solvent contained in the organic developer used for development processing in the solvent development process, any organic solvent that can dissolve the component (A) (component (A) before exposure) can be appropriately selected from known organic solvents. Specifically, examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, ether solvents, and hydrocarbon solvents.

[0780] A ketone solvent is an organic solvent containing C-C(=O)-C in its structure. An ester solvent is an organic solvent containing C-C(=O)-O-C in its structure. An alcohol solvent is an organic solvent containing an alcohol hydroxyl group in its structure. The "alcohol hydroxyl group" refers to a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. A nitrile solvent is an organic solvent containing a nitrile group in its structure. An amide solvent is an organic solvent containing an amide group in its structure. An ether solvent is an organic solvent containing C-O-C in its structure.

[0781] Among organic solvents, there are also organic solvents containing multiple functional groups characteristic of the above-mentioned respective solvents in their structures. In this case, the organic solvent belongs to all solvent types containing the functional groups it has at the same time. For example, diethylene glycol monomethyl ether belongs to both alcohol solvents or ether solvents in the above classification.

[0782] A hydrocarbon solvent is composed of a halogenatable hydrocarbon and is a hydrocarbon solvent having no substituents other than halogen atoms. As the halogen atom, examples include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferred.

[0783] Among the above, as the organic solvent contained in the organic developer, polar solvents are preferred, and ketone solvents, ester solvents, nitrile solvents, etc. are preferred.

[0784] As ketone solvents, for example, 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, diacetone, ionone, diacetone alcohol, acetyl methyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), etc. Among these, as the ketone solvent, methyl amyl ketone (2-heptanone) is preferred.

[0785] As ester solvents, for example, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, etc. Among these, as the ester solvent, butyl acetate is preferred.

[0786] As nitrile solvents, for example, acetonitrile, propionitrile, valeronitrile, butyronitrile, etc.

[0787] In the organic developer, known additives can be blended as needed. As such additives, for example, surfactants can be cited. As the surfactant, there is no particular limitation, and for example, ionic, non-ionic fluorine-based and / or silicon-based surfactants, etc. can be used. As the surfactant, a non-ionic surfactant is preferred, and a non-ionic fluorine-based surfactant or a non-ionic silicon-based surfactant is more preferred.

[0788] When a surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total amount of the organic developer.

[0789] The resist pattern forming method of the present embodiment is a particularly useful method when developing with an alkaline developer.

[0790] The development process can be carried out by a known development method. For example, methods such as immersing the support in the developer for a certain period of time (immersion method), carrying the developer on the surface of the support by surface tension and standing for a certain period of time (puddle method), spraying the developer onto the surface of the support (spray method), and continuously discharging the developer onto a support rotating at a certain speed while scanning the discharge nozzle of the developer at a certain speed (dynamic dispense method) can be cited.

[0791] As the organic solvent contained in the rinse liquid for the rinse treatment after the development treatment in the solvent development process, for example, an organic solvent that is difficult to dissolve the resist pattern can be appropriately selected and used from the organic solvents cited as the organic solvents for the organic developer. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents is preferred, at least one selected from alcohol solvents and ester solvents is more preferred, and alcohol solvents are particularly preferred.

[0792] The alcohol solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol can be any of linear, branched, or cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol, etc. can be cited. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred.

[0793] Any of these organic solvents can be used alone, or two or more can be used in combination. In addition, it can be used in combination with an organic solvent or water other than the above. Among them, considering the development characteristics, the blending amount of water in the rinse liquid is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, and particularly preferably 3% by mass or less, relative to the total amount of the rinse liquid.

[0794] In the rinsing liquid, known additives can be admixed as needed. Examples of such additives include surfactants. Examples of the surfactants include the same surfactants as described above, preferably nonionic surfactants, more preferably nonionic fluorosurfactants or nonionic siloxane surfactants.

[0795] When a surfactant is admixed, the admixing amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, more preferably 0.01 to 0.5% by mass with respect to the total amount of the rinsing liquid.

[0796] The rinsing treatment (cleaning treatment) using the rinsing liquid can be carried out by a known rinsing method. Examples of such a rinsing treatment method include a method of continuously discharging the rinsing liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinsing liquid for a certain period of time (dipping method), a method of spraying the rinsing liquid onto the surface of the support (spraying method), and the like.

[0797] According to the resist pattern forming method of the present embodiment described above, since the resist composition of the first embodiment is used, a resist pattern having high sensitivity and excellent lithography characteristics can be formed.

[0798] Examples

[0799] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0800] <Preparation of Resist Composition>

[0801] (Examples 1 to 12, Comparative Examples 1 to 8)

[0802] The respective components shown in Tables 1 and 2 were mixed and dissolved to prepare resist compositions for respective examples.

[0803] [Table 1]

[0804]

[0805] [Table 2]

[0806]

[0807] In Tables 1 and 2, each abbreviation has the following meanings. The values in [] are the admixing amounts (parts by mass).

[0808] (A1)-1: A polymer compound represented by the following chemical formula (A1-1). The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 7000, and the molecular weight distribution coefficient (Mw / Mn) is 1.5. By 13The copolymerization composition ratio determined by \(^{13}\)C-NMR (the ratio of each structural unit in the structural formula (molar ratio)) is l / m / n / o = 40 / 35 / 15 / 10.

[0809] (A1)-2: A polymer compound represented by the following chemical formula (A1-2). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 7700, and the molecular weight distribution coefficient (Mw / Mn) is 1.44. By 13 The copolymerization composition ratio determined by \(^{13}\)C-NMR (the ratio of each structural unit in the structural formula (molar ratio)) is l / m = 50 / 50.

[0810] (A1)-3: A polymer compound represented by the following chemical formula (A1-3). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 6600, and the molecular weight distribution coefficient (Mw / Mn) is 1.61. By 13 The copolymerization composition ratio determined by \(^{13}\)C-NMR (the ratio of each structural unit in the structural formula (molar ratio)) is l / m = 50 / 50.

[0811] (A1)-4: A polymer compound represented by the following chemical formula (A1-4). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 6500, and the molecular weight distribution coefficient (Mw / Mn) is 1.57. By 13 The copolymerization composition ratio determined by \(^{13}\)C-NMR (the ratio of each structural unit in the structural formula (molar ratio)) is l / m / n / o = 30 / 35 / 10 / 25.

[0812] (A1)-5: A polymer compound represented by the following chemical formula (A1-5). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 5100, and the molecular weight distribution coefficient (Mw / Mn) is 1.52. By 13 The copolymerization composition ratio determined by \(^{13}\)C-NMR (the ratio of each structural unit in the structural formula (molar ratio)) is l / m / n / o = 35 / 30 / 5 / 30.

[0813] (A2)-1: A polymer compound represented by the following chemical formula (A2-1). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 6700, and the molecular weight distribution coefficient (Mw / Mn) is 1.65. By 13 The copolymerization composition ratio determined by \(^{13}\)C-NMR (the ratio of each structural unit in the structural formula (molar ratio)) is l / m = 50 / 50.

[0814] (A2)-2: A polymer compound represented by the following chemical formula (A2-2). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 7,400, and the molecular weight distribution coefficient (Mw / Mn) is 1.40. By 13 C-NMR measurement, the copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) is l / m = 50 / 50.

[0815] (A2)-3: A polymer compound represented by the following chemical formula (A2-3). The weight-average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 5,400, and the molecular weight distribution coefficient (Mw / Mn) is 1.45. By 13 C-NMR measurement, the copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) is l / m / n / o = 45 / 40 / 5 / 10.

[0816] [Chemical formula 79]

[0817]

[0818] [Chemical formula 80]

[0819]

[0820] [Chemical formula 81]

[0821]

[0822] (B1)-1 to (B1)-5: Acid generators composed of compounds represented by the following chemical formulas (B1-1) to (B1-5), respectively.

[0823] (B2)-1 to (B2)-2: Acid generators composed of compounds represented by the following chemical formulas (B2-1) to (B2-2), respectively.

[0824] [Chemical formula 82]

[0825]

[0826] [Chemical formula 83]

[0827]

[0828] (D1)-1 to (D1)-5: Acid diffusion control agents composed of compounds represented by the following chemical formulas (D1-1) to (D1-4), respectively.

[0829] (D2)-1 to (D2)-3: Acid diffusion control agents composed of compounds represented by the following chemical formulas (D2-1) to (D2-3), respectively.

[0830] [Chemical formula 84]

[0831]

[0832] [Chemical formula 85]

[0833]

[0834] (S1)-1: γ-butyrolactone.

[0835] (S2)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / cyclohexanone = 1140 / 760 / 635 (mass ratio).

[0836] <Formation of resist pattern 1>

[0837] On a 12-inch silicon wafer, an organic antireflective film composition "ARC29A" (manufactured by BrewerScience) was coated using a spin coater and baked on a hot plate at 205°C for 60 seconds to dry it, thereby forming an organic antireflective film with a film thickness of 98 nm.

[0838] On the said organic antireflective film, the resist compositions of each example were respectively coated using a spin coater, and pre-baked (PAB) on a hot plate at 90°C for 60 seconds to dry it, forming a resist film with a film thickness of 130 nm. Thereafter, a top coat was coated on the resist film using a spin coater, and baked on a hot plate at 90°C for 60 seconds to form a top coat film with a film thickness of 35 nm.

[0839] Next, using an immersion ArF exposure apparatus XT1900Gi [manufactured by ASML; NA (numerical aperture) = 1.35, Conventional, Sigma 0.94, immersion medium: ultrapure water], ArF excimer laser (193 nm) was selectively irradiated via a photomask (6% halftone). Thereafter, PEB treatment was performed at 80°C for 60 seconds. Then, alkaline development was carried out at 23°C for 20 seconds using a 2.38 mass% TMAH aqueous solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.), followed by water rinsing with pure water for 15 seconds, and spin drying. As a result, contact hole patterns (hereinafter referred to as "CH patterns") with a pore diameter of 68 nm and a pitch of 160 nm (mask size 85 nm) were respectively formed in any of the examples.

[0840] [Evaluation of optimal exposure dose (Eop)]

[0841] The optimal exposure dose Eop (μC / cm) for forming a CH pattern with a target size (pore diameter 68 nm, pitch 160 nm) was obtained through the above <Formation of resist pattern 1> 2)。Take it as "Eop(μC / cm 2 )" and show it in Table 3 and Table 4.

[0842] <Evaluation of In-Plane Uniformity (CDU) of Pattern Size>

[0843] Using a length-measuring SEM (scanning electron microscope, acceleration voltage 500V, trade name: CG5000, manufactured by Hitachi High-Technologies Corporation), observe 100 holes in the CH pattern from above, and measure the pore diameter (nm) of each hole. Calculate three times the standard deviation (σ) calculated from the measurement results. Show this result as "CDU" in Table 3 and Table 4. The smaller the value of 3σ obtained in this way, the higher the in-plane uniformity of the sizes (CD) of the multiple holes formed on the resist film.

[0844] <Formation of Resist Pattern 2>

[0845] On a 12-inch silicon wafer, spin-coat the organic antireflective film composition "ARC29A" (manufactured by BrewerScience) and bake it on a hot plate at 205°C for 60 seconds to dry it, thereby forming an organic antireflective film with a film thickness of 89 nm.

[0846] On the organic antireflective film, spin-coat the resist composition of each example and perform a pre-bake (PAB) treatment on a hot plate at 90°C for 60 seconds to dry it, forming a resist film with a film thickness of 130 nm. Thereafter, spin-coat a top coat on the resist film and perform a baking treatment on a hot plate at 90°C for 60 seconds to form a top coat film with a film thickness of 35 nm.

[0847] Next, using an immersion ArF exposure apparatus XT1900Gi [manufactured by ASML; NA (numerical aperture) = 1.07, C-Quad, Sigma (Outer 0.82, Inner 0.66), TE deflection, immersion medium: ultrapure water], selectively irradiate ArF excimer laser (193 nm) through a photomask (6% halftone). Thereafter, perform a PEB treatment at 80°C for 60 seconds. Then, develop it with a 2.38 mass% aqueous TMAH solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C for 10 seconds, then rinse it with pure water for 15 seconds, and perform spin-drying. As a result, a 1:1 line-and-space pattern with a line width of 65 nm (hereinafter referred to as "LS pattern") was formed in each example.

[0848] [Evaluation of Defects (Number of Defects)]

[0849] Using a surface defect observation device (product name: KLA2905, manufactured by KLA Tencor Corporation), the total number of defects (total number of all defects) in the wafer was measured for the LS pattern formed by the above <Formation of Resist Pattern 2>. The number of defects was evaluated according to the following evaluation criteria, and the evaluation results were shown as "number of defects" in Tables 3 and 4.

[0850] Evaluation Criteria

[0851] A: The number of defects is 100 or less

[0852] B: The number of defects is more than 100 and 200 or less

[0853] C: The number of defects exceeds 200

[0854] [Table 3]

[0855]

[0856] [Table 4]

[0857]

[0858] From the results shown in Tables 3 and 4, it can be confirmed that, compared with the resist composition of the comparative example, the resist composition according to the embodiment can form a resist pattern with improved sensitivity while maintaining CDU and having fewer defects.

[0859] As described above, although the preferred embodiments of the present invention have been described, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other changes to the constitution can be made without departing from the gist of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, characterized in that Comprising: A substrate component (A) whose solubility in a developer changes due to the action of an acid; An acid generator component (B) that generates an acid upon exposure; An acid diffusion control agent component (D), The substrate component (A) includes a polymer compound (A1) having a structural unit (a0) represented by the following general formula (a0-1), The acid generator component (B) includes a compound (B1) represented by the following general formula (b1), The acid diffusion control agent component (D) includes a compound (D1) represented by the following general formula (d1), [Chemical formula 1] In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, Va 01 represents a divalent linking group, n a01 is an integer of 1 to 2, Ra 01 represents a lactone ring-containing group having at least one substituent selected from the group consisting of a halogen atom, a carboxyl group, an acyl group, a nitro group, and a cyano group, [Chemical formula 2] In the formula, Yb 01 represents a divalent linking group or a single bond, and Lb 01 represents -C(=O)-O-, -O-C(=O)-, -O- or -O-C(=O)-Lb 011 -, and Lb 011 represents an alkylene group having 1 to 3 carbon atoms, and Rb 01 to Rb 03 each independently represents an alkyl group, and two or more of Rb 01 to Rb 03 can be bonded to each other to form a ring structure, and Rb 04 to Rb 06 each independently represents an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group or a nitro group, and n b04 represents an integer of 0 to 4, and n b05 to n b06 each independently represents an integer of 0 to 5, and X - represents a counter anion. [Chemical formula 3] In the formula, Rd 01 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, wherein a fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in the formula, m is an integer of 1 or more, and M m+ each independently represents an m-valent organic cation.

2. The resist composition according to claim 1, wherein Ra in the general formula (a0-1) 01 is a lactone ring-containing group represented by the following general formula (Ra0-1), [Chemical formula 4] In the formula, Ra 012 and Ra 013 each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkylthio group having 1 to 5 carbon atoms, or Ra 012 and Ra 013 are bonded to each other to represent an alkylene group having 1 to 6 carbon atoms which may contain an oxygen atom or a sulfur atom, an ether bond (-O-), or a thioether bond (-S-), X 011 represents a halogen atom, a carboxyl group, an acyl group, a nitro group, or a cyano group, Ra 011 represents an alkyl group having 1 to 6 carbon atoms which may contain a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxy moiety may be protected by a protecting group and which may contain a halogen atom, a carboxyl group capable of forming a salt, or a substituted oxycarbonyl group, p 01 represents an integer of 0 to 8, q 01 represents an integer of 1 to 9, wherein, p 01 +q 01 ≤9, in the case where there are two or more X 011 , the plurality of X 011 may be the same or different from each other, in the case where there are two or more Ra 011 , the plurality of Ra 011 may be the same or different from each other, in the case where Ra 012 and Ra 013 are bonded to each other to form an alkylene group having 1 to 6 carbon atoms which may contain an oxygen atom or a sulfur atom, X 011 and Ra 011 may each independently exist as a substituent of the hydrogen atom substituting the alkylene group having 1 to 6 carbon atoms, and * represents a chemical bond bonded to the oxygen atom in the formula (a0-1).

3. A method for forming a resist pattern, characterized in that, Having: A step of forming a resist film using the resist composition according to claim 1 or 2 on a support, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern.

Images