Resist composition, method for forming resist pattern, copolymer, and compound

Abstract

To provide a resist composition and the like which achieve high sensitivity during the formation of a resist pattern and enhances both effects of roughness reduction and film loss suppression.SOLUTION: The present invention employs a resist composition which contains a copolymer that has a constituent unit represented by general formula (a00), a constituent unit represented by general formula (a01), and a constituent unit represented by general formula (a02). In the formulas: R0a, R0b, R01 and R02 are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom; L00 and L01 are each independently a divalent linking group or a single bond; L02 is a divalent linking group; RAr is an aromatic group which may have a specific substituent; RX is an acid dissociable group; and Z- is an anion group.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In recent years, advances in lithography technology have led to rapid advances in the miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display devices. A common method for achieving this miniaturization is to shorten the wavelength (increase the energy) of the exposure light source. Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with minute dimensions. To satisfy these requirements, a chemically amplified resist composition has been used, which contains a base component whose solubility in a developer changes due to the action of acid, and an acid generator component that generates acid upon exposure.

[0003] In chemically amplified resist compositions, a resin having a plurality of structural units is generally used as the base component in order to improve lithography properties, etc. A wide variety of acid generators have been proposed so far. For example, onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, disulfone-based acid generators, etc. are known.

[0004] Furthermore, in chemically amplified resist compositions, polymeric compounds have been proposed that incorporate structural units containing acid generating groups that generate acid upon exposure as acid generator components (see, for example, Patent Document 1). Such polymeric compounds function both as acid generators and as base components. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-197168 Summary of the Invention [Problem to be solved by the invention]

[0006] As lithography technology advances and resist patterns become increasingly finer, the goal is to form fine patterns of several tens of nanometers, for example, in lithography using EUV (extreme ultraviolet) or EB (electron beam). As pattern dimensions become smaller, both high sensitivity to the exposure light source and lithography properties such as reduced roughness are required. In addition, as resist patterns become finer, excessive dissolution of the resist film, particularly the unexposed portions, in the developer during development can cause development loss (film loss). However, conventional resist compositions such as those described in Patent Document 1 require further improvement in terms of these required properties.

[0007] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a resist composition that enables high sensitivity in resist pattern formation, and is effective in both reducing roughness and suppressing film loss; a method of forming a resist pattern that uses this resist composition; a copolymer that is useful for this resist composition; and a compound that can be used to synthesize this copolymer. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration. That is, a first aspect of the present invention is a resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition containing a resin component whose solubility in a developer changes due to the action of the acid, the resin component containing a copolymer having a structural unit represented by the following general formula (a00), a structural unit represented by the following general formula (a01), and a structural unit represented by the following general formula (a02) that generates acid upon exposure.

[0009] [ka] [In formula (a00), R 0a and R 0b are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 00 is a divalent linking group or a single bond. Ar is an aromatic group which may have a substituent. The substituent which this aromatic group may have is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, an aryl group, an alkoxy group, and a hydroxy group. 01 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 01 is a divalent linking group or a single bond. X is an acid-dissociable group. 02 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 02 is a divalent linking group. - is an anionic group. M m+ is an onium cation with a valence of m, where m is an integer of 1 or greater.

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

[0011] A third aspect of the present invention is a copolymer having a structural unit represented by the following general formula (a00), a structural unit represented by the following general formula (a01), and a structural unit represented by the following general formula (a02) that generates acid upon exposure.

[0012] [ka] [In formula (a00), R 0a and R 0b are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 00 is a divalent linking group or a single bond. Ar is an aromatic group which may have a substituent. The substituent which this aromatic group may have is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, an aryl group, an alkoxy group, and a hydroxy group. 01 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 01 is a divalent linking group or a single bond. X is an acid-dissociable group. 02 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 02 is a divalent linking group. - is an anionic group. M m+ is an onium cation with a valence of m, where m is an integer of 1 or greater.

[0013] A fourth aspect of the present invention is a compound represented by the following general formula (a00-M1) or general formula (a00-M2).

[0014] [ka] [In formula (a00-M1) and formula (a00-M2), R 0a and R 0b are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 00 is a divalent linking group or a single bond. 0c is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, and an aryl group. p is an integer of 1 to 4. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a resist composition that enables high sensitivity in resist pattern formation, and is effective in both reducing roughness and suppressing film loss; a method of forming a resist pattern that uses this resist composition; a copolymer useful for this resist composition; and a compound that can be used in synthesizing this copolymer. DETAILED DESCRIPTION OF THE INVENTION

[0016] In this specification and claims, the term "aliphatic" is defined as a relative concept to aromatic, and refers to groups, compounds, etc. that do not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, the term "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups. The "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). The phrase "may have a substituent" includes both the case where a hydrogen atom (-H) is replaced with a monovalent group and the case where a methylene group (-CH2-) is replaced with a divalent group. The term "exposure" is a general concept that includes irradiation with radiation.

[0017] The term "acid-decomposable group" refers to a group having acid decomposability in which at least some of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that decompose under the action of an acid to generate a polar group. Examples of polar groups include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO3H). More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0018] The term "acid-dissociable group" refers to either (i) a group having acid dissociability such that the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group in which a portion of the bond is cleaved by the action of an acid, and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group. The acid-dissociable group constituting the acid-decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid-dissociable group. Therefore, when the acid-dissociable group dissociates due to the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, increasing the polarity. As a result, the polarity of the entire component (A1) increases. The increase in polarity relatively changes the solubility in the developer, increasing the solubility when the developer is an alkaline developer and decreasing the solubility when the developer is an organic developer.

[0019] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly classified into non-polymers and polymers. Non-polymers typically have a molecular weight of 500 or more and less than 4000 (hereinafter referred to as "low molecular weight compounds"). Hereinafter, the terms "resin," "high molecular weight compound," or "polymer" refer to a polymer with a molecular weight of 1000 or more. The molecular weight of a polymer is determined by the weight average molecular weight converted into polystyrene by GPC (gel permeation chromatography).

[0020] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, such as an ethylenic double bond. In the "acrylic acid ester", the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. αx ) is an atom or group other than a hydrogen atom. αx) is substituted with a substituent containing an ester bond, or αx This also includes α-hydroxyacrylic esters in which the hydroxyl group is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group. Unless otherwise specified, the α-carbon atom of an acrylic ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylic ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylic ester.

[0021] The term "derivative" encompasses compounds in which the hydrogen atom at the α-position of the target compound is substituted with another substituent, such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include compounds in which the hydrogen atom of a hydroxyl group of a target compound, which may have the hydrogen atom at the α-position substituted with a substituent, is substituted with an organic group; and compounds in which a substituent other than a hydroxyl group is bonded to a target compound, which may have the hydrogen atom at the α-position substituted with a substituent. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. The substituents that replace the hydrogen atom at the α-position of hydroxystyrene include R αx Examples include alkyl groups, halogenated alkyl groups, and the like.

[0022] In this specification and claims, some structures represented by chemical formulas may have asymmetric carbon atoms, and may exist as enantiomers or diastereomers. In such cases, a single chemical formula represents all isomers. These isomers may be used alone or as a mixture.

[0023] (Resist composition) In one embodiment of the resist composition, an acid is generated upon exposure, and the solubility in a developer is changed by the action of the acid. The resist composition of this embodiment contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes under the action of an acid. In this resist composition, component (A) contains a resin component (hereinafter also referred to as "component (A1)") whose solubility in a developer changes under the action of an acid. The component (A1) contains a copolymer (hereinafter, this copolymer is also referred to as "component (A1-0)") having a structural unit represented by general formula (a00), which will be described later, a structural unit represented by general formula (a01), and a structural unit represented by general formula (a02) that generates acid upon exposure.

[0024] When a resist film is formed using the resist composition of this embodiment and then subjected to selective exposure, an acid is generated from at least the component (A1-0) in the exposed areas of the resist film, and the action of this acid changes the solubility of the component (A1) in a developer, while the solubility of the component (A1) in a developer does not change in the unexposed areas of the resist film, resulting in a difference in solubility in a developer between the exposed and unexposed areas of the resist film. Therefore, when the resist film is developed, if the resist composition is positive, the exposed areas of the resist film are dissolved and removed, forming a positive resist pattern, whereas if the resist composition is negative, the unexposed areas of the resist film are dissolved and removed, forming a negative resist pattern.

[0025] The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Furthermore, the resist composition of this embodiment may be for an alkaline development process in which an alkaline developer is used in the development treatment during resist pattern formation, or may be for a solvent development process in which a developer containing an organic solvent (organic developer) is used in the development treatment.

[0026] <Base material component (A)> In the resist composition of this embodiment, the component (A) contains a resin component (component (A1)) whose solubility in a developer changes under the action of acid. By using the component (A1), good development contrast can be obtained not only in an alkaline development process but also in a solvent development process. As the component (A), at least one of another high molecular weight compound and a low molecular weight compound may be used in combination with the component (A1). In the resist composition of this embodiment, the component (A) may use either a single type of compound, or a combination of two or more types of compounds.

[0027] About the resin component (A1) The component (A1) contains a copolymer (component (A1-0)) having a structural unit represented by general formula (a00) (hereinafter referred to as "structural unit (a00)"), a structural unit represented by general formula (a01) (hereinafter referred to as "structural unit (a01)"), and a structural unit represented by general formula (a02) that generates acid upon exposure (hereinafter referred to as "structural unit (a02)"). The component (A1-0) may be a copolymer containing the structural units (a00), (a01), and (a02), as well as other structural units, as necessary.

[0028] <Constituent unit (a00)> The structural unit (a00) is a structural unit represented by the following general formula (a00): This structural unit (a00) has a maleimide structure and functions as a proton source.

[0029] [ka] [In formula (a00), R 0a and R 0b are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 00 is a divalent linking group or a single bond. Arrepresents an aromatic group which may have a substituent, provided that the substituent which this aromatic group may have is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, an aryl group, an alkoxy group, and a hydroxy group.

[0030] In the formula (a00), R 0a and R 0b are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. R 0a and R 0b In the formula (I), the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. As the halogen atom in the halogenated alkyl group, a fluorine atom is particularly preferred. R 0a and R 0b are each preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability, and even more preferably a hydrogen atom; R 0a and R 0b It is particularly preferred that all of these are hydrogen atoms.

[0031] In the formula (a00), L 00 is a divalent linking group or a single bond. L 00 Examples of the divalent linking group in the formula include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and a combination thereof.

[0032] L 00an optionally substituted divalent hydrocarbon group in the formula: L 00 In the above formula, the divalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0033] ··L 00 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in its structure.

[0034] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0035] L 00 When is a chain hydrocarbon group, some or all of the hydrogen atoms of the chain hydrocarbon group may be substituted with a monovalent group containing a heteroatom. Examples of the monovalent group include a halogen atom, a nitro group, an amino group, a hydroxy group, a carboxy group, a nitrile group, and a thiol group. L 00 is a chain hydrocarbon group, the methylene group of the chain hydrocarbon group may be substituted with a divalent group containing a heteroatom. Examples of the divalent group include a carbonyl group, an ether bond [-O-], an ester bond [-C(=O)-O-, -OC(=O)-], an amide group [-C(=O)-NH-, -HN-C(=O)-], and [-NH-].

[0036] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, which may substitute a hydrogen atom bonded to the linear aliphatic hydrocarbon group, or may substitute a methylene group (—CH—) constituting the linear aliphatic hydrocarbon group.

[0037] Examples of groups that can substitute hydrogen atoms bonded to the chain aliphatic hydrocarbon group include alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxy groups, nitro groups, amino groups, carboxy groups, nitrile groups, and thiol groups. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and even more preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with the halogen atoms.

[0038] Substituents for the methylene group (-CH2-) that constitutes the chain aliphatic hydrocarbon group include a carbonyl group, an ether bond [-O-], an ester bond [-C(=O)-O-, -OC(=O)-], an amide group [-C(=O)-NH-, -HN-C(=O)-], and an imino group [-NH-].

[0039] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in its structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group here include the same as those described above as "linear or branched aliphatic hydrocarbon groups."

[0040] The cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring: an alicyclic hydrocarbon group) preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0041] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include the substituents exemplified above as "substituting a hydrogen atom bonded to the chain aliphatic hydrocarbon group." In the cyclic aliphatic hydrocarbon group, a methylene group constituting the ring structure may be substituted with a divalent group containing a heteroatom, such as a carbonyl group, an ether bond [-O-], an ester bond [-C(=O)-O-], -S-, -S(=O)2-, -S(=O)2-O-, an amide group [-C(=O)-NH-], or an imino group [-NH-].

[0042] ··L 00 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings.

[0043] L 00 Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (an arylene group or a heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.); and a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (an aryl group or a heteroaryl group), in which one hydrogen atom has been substituted with an alkylene group (for example, a group in which one further hydrogen atom has been removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0044] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxy group. Examples of the alkyl group, alkoxy group, halogen atom and halogenated alkyl group as the substituent include the substituents exemplified above as "substituting a hydrogen atom bonded to a cyclic aliphatic hydrocarbon group".

[0045] L 00 A divalent linking group containing a heteroatom in Preferred examples of the divalent linking group containing a hetero atom include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2-, -S(=O)2-O-, and groups represented by the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -, wherein Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 1 to 3.

[0046] When the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, an acyl group, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms.

[0047] General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21-C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -Medium, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the above-mentioned L 00 Examples of the divalent linking group include the same groups as those (divalent hydrocarbon groups which may have a substituent) mentioned in the description of the divalent linking group in the above. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferred, a straight-chain alkylene group is more preferred, a straight-chain alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred. Y 22 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

[0048] Formula − [Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, m" is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. That is, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by - is a group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0049] Among the above, L 00 is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. 00 is preferably a single bond.

[0050] In the formula (a00), R Ar is an aromatic group which may have a substituent. R Ar The aromatic group may be monocyclic or polycyclic. The aromatic group preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 10 carbon atoms.

[0051] Specific examples of the aromatic ring contained in the aromatic group include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a portion of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specifically, the aromatic group is preferably a group in which two hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, more preferably a group in which two hydrogen atoms have been removed from benzene or naphthalene (i.e., a phenylene group or a naphthylene group), and even more preferably a group in which two hydrogen atoms have been removed from benzene (i.e., a phenylene group).

[0052] However, R ArThe substituent that the aromatic group in formula (I) may have is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, an aryl group, an alkoxy group, and a hydroxy group. The halogen atom as the substituent is preferably a fluorine atom, an iodine atom, or a bromine atom, more preferably an iodine atom or a fluorine atom, and among these, an iodine atom is even more preferable from the viewpoint of the effects of sensitivity, reduction in roughness, and suppression of film loss. The alkyl group as the substituent may be linear or branched, and is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with the halogen atoms. The aryl group as the substituent includes an aryl group having 6 to 20 carbon atoms, preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and still more preferably a methoxy group or an ethoxy group. R Ar The substituent that the aromatic group in the formula (I) may have is preferably at least one selected from the group consisting of a halogen atom and an alkyl group, and among these, a halogen atom is more preferable in terms of the effects of sensitivity, reduction in roughness, and suppression of film loss.

[0053] Among the above, R ArAs the substituent, it is preferable that the aromatic group may have at least one substituent selected from the group consisting of a halogen atom and an alkyl group, and it is more preferable that the aromatic group may have at least one substituent selected from a halogen atom. In particular, it is even more preferable that the aromatic group has an iodine atom as a substituent, since this tends to improve the effects of sensitivity, reduction of roughness, and suppression of film loss.

[0054] A preferred example of the structural unit (a00) is a structural unit represented by the following general formula (a00-u).

[0055] [ka] [In formula (a00-u), R 0a and R 0b are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 00 is a divalent linking group or a single bond. 0c is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, and an aryl group. p' is an integer of 0 to 4.

[0056] In the formula (a00-u), R 0a and R 0b , L 00 represents R in the above general formula (a00). 0a and R 0b , L 00 This is the same as the explanation for R 0a and R 0b are each preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, and R 0a and R 0b It is particularly preferred that all of these are hydrogen atoms. L 00 is preferably a single bond. p' is an integer of 0 to 4, preferably an integer of 0 to 2, and more preferably 0 or 1. R0c is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, and an aryl group, is preferably at least one selected from the group consisting of a halogen atom and an alkyl group, is more preferably a halogen atom, and among these, is further preferably an iodine atom from the viewpoints of the effects of sensitivity, reduction in roughness, and suppression of film loss. The bonding position of the hydroxy group (-OH) on the benzene ring in formula (a00-u) may be any of the ortho, meta, and para positions. From the viewpoint of the effect of suppressing film loss, the bonding position of the hydroxy group (-OH) on the benzene ring is more preferably the ortho or meta position. From the viewpoints of the effects of sensitivity, reduction in roughness, and suppression of film loss, as well as ease of synthesis, the para position is more preferred.

[0057] Specific examples of the structural unit (a00) are shown below. In each of the following formulas, R 00a and R 00b each independently represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0058] [ka]

[0059] [ka]

[0060] The structural unit (a00) is preferably selected from the group consisting of structural units represented by the above chemical formulas (a00-u1-01) to (a00-u1-14), structural units represented by the above chemical formulas (a00-u2-01) to (a00-u2-14), and structural units represented by the chemical formula (a00-u3-01). Among these, the structural unit (a00) includes the structural units represented by the above chemical formulas (a00-u1-01), (a00-u1-06), (a00-u1-07), and (a00-u1-09); the structural units represented by the chemical formulas (a00-u2-01), (a00-u2-06), (a00-u2-07), and (a00-u2-08); and It is more preferable to select from the group consisting of structural units represented by formula (a00-u3-01), and from the standpoint of sensitivity, roughness reduction and film loss suppression effects, it is even more preferable to select from the group consisting of structural units represented by chemical formula (a00-u1-07) and chemical formula (a00-u1-09); and structural units represented by chemical formula (a00-u2-07) and chemical formula (a00-u2-08).

[0061] The structural unit (a00) contained in the component (A1-0) may be of one type, or may be of two or more types. The proportion of the structural unit (a00) in the component (A1-0) is preferably 5 to 45 mol %, more preferably 10 to 40 mol %, and even more preferably 20 to 35 mol %, based on the total (100 mol %) of all structural units that make up the component (A1-0). By ensuring that the proportion of the structural unit (a00) is at least as large as the lower limit of the above-mentioned preferred range, high sensitivity can be achieved in resist pattern formation, and the effect of reducing roughness can be enhanced. On the other hand, by ensuring that the proportion is at most the upper limit of the above-mentioned preferred range, a balance with other structural units can be achieved, and various lithography properties can be improved.

[0062] <Constituent unit (a01)> The structural unit (a01) is a structural unit represented by the following general formula (a01): This structural unit (a01) is a structural unit that contains an acid-decomposable group whose polarity increases when exposed to an acid. In the structural unit (a01), the acid-decomposable group decomposes when exposed to an acid to generate a carboxy group.

[0063] [ka] [In formula (a01), R01 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 01 is a divalent linking group or a single bond. X is an acid-dissociable group.

[0064] In the formula (a01), R 01 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. R 01 The alkyl group having 1 to 5 carbon atoms in the formula (I) is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferred. R 01 As the alkyl group, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, and a hydrogen atom or a methyl group is more preferred from the viewpoint of industrial availability.

[0065] In the formula (a01), L 01 is a divalent linking group or a single bond. L 01 Examples of the divalent linking group in the formula (a00) include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and a combination thereof. 00 Examples of the divalent hydrocarbon group which may have a substituent, the divalent linking group containing a hetero atom, and combinations thereof are the same as those exemplified in the description of the above. Among the above, L 01 is preferably a single bond, an ester bond [—C(═O)—O—], an aliphatic hydrocarbon group containing a ring in the structure, an aromatic hydrocarbon group, or a combination thereof.

[0066] L01 In the above, preferred examples of the aliphatic hydrocarbon group containing a ring in its structure include cyclic aliphatic hydrocarbon groups (groups in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a hetero atom in the ring structure. The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, or a carbonyl group. In the cyclic aliphatic hydrocarbon group, a methylene group constituting the ring structure may be substituted with a divalent group containing a heteroatom, such as a carbonyl group, an ether bond [-O-], an ester bond [-C(=O)-O-], -S-, -S(=O)2-, -S(=O)2-O-, an amide group [-C(=O)-NH-], or an imino group [-NH-].

[0067] L 01 In the above formula, the aromatic hydrocarbon group is preferably a group (arylene group or heteroarylene group) in which two hydrogen atoms have been removed from an aromatic hydrocarbon ring or an aromatic heterocycle. The hydrogen atoms of the aromatic hydrocarbon group may be substituted with a substituent.

[0068] In the formula (a01), R X is an acid-dissociable group. R X Examples of the acid-dissociable group in the formula (I) include those that have been proposed as acid-dissociable groups in base resins for chemically amplified resist compositions. Specific examples of acid-dissociable groups that have been proposed for use in base resins for chemically amplified resist compositions include the "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "secondary alkyl ester-type acid-dissociable groups," which are described below.

[0069] Acetal type acid dissociable group: R XExamples of the acid-dissociable group in the formula (a1-r-1) include acid-dissociable groups represented by the following general formula (a1-r-1) (hereinafter, sometimes referred to as "acetal-type acid-dissociable group").

[0070] [ka] [In the formula, Ra' 1 and Ra' 2 Each of Ra' is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.]

[0071] In formula (a1-r-1), Ra' 1 and Ra' 2 At least one of these is preferably a hydrogen atom, and both are more preferably hydrogen atoms. Ra' 1 or Ra' 2 When is an alkyl group, the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. Specific examples thereof include linear and branched alkyl groups. More specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. Methyl and ethyl groups are more preferred, and methyl groups are particularly preferred.

[0072] In formula (a1-r-1), Ra' 3 Examples of the hydrocarbon group include a linear or branched alkyl group, and a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Of these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred. The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0073] Ra' 3 When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a monocyclic group or a polycyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] 2,6 ]decane, tetracyclododecane, and the like.

[0074] Ra' 3 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings. Ra' 3 Specific examples of the aromatic hydrocarbon group in the formula (I) include a group (aryl group or heteroaryl group) in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle; a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0075] Ra' 3 The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (hereinafter these substituents are collectively referred to as "Ra x5 ") are also examples. where R P1 is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, R P1 and R P2Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group, and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents, or may have one or more of each of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; 2,6 ]decanyl group, tricyclo[3.3.1.1 3,7 ]decanyl group, tetracyclo[6.2.1.1 3,6 .0 2,7 ] Examples include polycyclic aliphatic saturated hydrocarbon groups such as a dodecanyl group and an adamantyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0076] Ra' 3 But Ra' 1 , Ra' 2 When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0077] Tertiary alkyl ester-type acid-labile group: R X Examples of the acid-dissociable group in the formula (a1-r-2) include acid-dissociable groups represented by the following general formula (a1-r-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group may be referred to as "tertiary alkyl ester-type acid-dissociable groups" hereinafter for convenience.

[0078] [ka] [In the formula, Ra' 4 ~Ra' 6 are each independently a hydrocarbon group which may have a substituent, and Ra' 5 and Ra' 6 may be bonded to each other to form a ring.

[0079] Ra' 4 Examples of the hydrocarbon group include a linear or branched alkyl group which may have a substituent, a linear or cyclic alkenyl group which may have a substituent, and a cyclic hydrocarbon group which may have a substituent. Ra' 4 The linear or branched alkyl group and the cyclic hydrocarbon group (the monocyclic aliphatic hydrocarbon group, the polycyclic aliphatic hydrocarbon group, and the aromatic hydrocarbon group) in 3 The same can be mentioned. Ra' 4 The chain or cyclic alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 The hydrocarbon group of Ra' 3 The same can be mentioned.

[0080] Ra' 5 and Ra' 6 and (a1-r2-3) are preferably substituted or unsubstituted by the alkyl group. On the other hand, Ra' 4 ~Ra' 6 When are not bonded to each other and are independent hydrocarbon groups, preferred examples include groups represented by the following general formula (a1-r2-4).

[0081] [ka] [In formula (a1-r2-1), Ra' 10 Ra' represents a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group. 11 Ra' 10 represents a group that forms an aliphatic cyclic group together with the carbon atom to which 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. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Some of the carbon atoms that constitute the ring of this cyclic hydrocarbon group may be substituted with a heteroatom-containing group. Ra 101 ~Ra 103 are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. 101 ~Ra 103 Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group which forms an aliphatic cyclic group together with Yaa. Ra 104 In formula (a1-r2-4), Ra' is an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent. 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * indicates a bond (the same applies hereinafter).

[0082] In the above formula (a1-r2-1), Ra' 10 is a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group. Ra' 10 The linear alkyl group in the formula (I) has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra' 10 In the formula (I), the branched alkyl group is the above-mentioned Ra' 3 The same can be mentioned.

[0083] Ra' 10 The alkyl group in may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Furthermore, some of the carbon atoms (e.g., methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. The heteroatom includes an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0084] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed together with the carbon atom to which the carbon atom is bonded is represented by Ra' in formula (a1-r-1). 3 Among these, the monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl, cyclohexyl, and tetrahydrofuranyl groups are more preferred. 11 In the formula (I), some of the carbon atoms constituting the ring may be substituted with a heteroatom-containing group. Examples of the heteroatom-containing group include the same as those mentioned above.

[0085] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the formula (a1-r-1). 3 Examples include groups in which one or more hydrogen atoms have been further removed from a cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in the following formula: Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, a cyclopentyl group and a cyclohexyl group are more preferred. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. The substituent may be any of the above-mentioned Ra' 3 Examples of the substituents include the same as those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 101 ~Ra 103 In the formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Ra 101 ~Ra 103 In the formula (I), examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; 2,6 ]decanyl group, tricyclo[3.3.1.13,7 ]decanyl group, tetracyclo[6.2.1.1 3,6 .0 2,7 ] Examples thereof include polycyclic aliphatic saturated hydrocarbon groups such as a dodecanyl group and an adamantyl group. Ra 101 ~Ra 103 Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferred, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferred, with a hydrogen atom being particularly preferred.

[0091] The above Ra 101 ~Ra 103 Examples of the substituents that the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the formula: x5 The same groups as those shown below can be mentioned.

[0092] Ra 101 ~Ra 103 Examples of the group containing a carbon-carbon double bond formed by two or more of the above being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidene-ethenyl group, a cyclohexylidene-ethenyl group, etc. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0093] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). 3 The groups exemplified as the aliphatic hydrocarbon group, which is a monocyclic or polycyclic group, are preferred. In the aliphatic cyclic group, some of the carbon atoms constituting the ring may be substituted with a heteroatom-containing group. Examples of the heteroatom-containing group include the same as those mentioned above. The aliphatic cyclic group formed by Xaa together with Yaa is preferably a monocyclic group, more preferably a cyclopentyl group, a cyclohexyl group, or a tetrahydrofuranyl group. In formula (a1-r2-3), Ra 104 Examples of the aromatic hydrocarbon group in the formula include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. 104 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene. Ra 104 The aromatic heterocyclic group in the formula (I) includes those containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

[0098] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed by include a methyl group, an ethyl group, a propyl group, a hydroxy group, a carboxy group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), and an alkyloxycarbonyl group.

[0099] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0100] [ka]

[0101] [ka]

[0102] In formula (a1-r2-4), Ra' 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. 12 and Ra' 13 In the formula, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned Ra 101 ~Ra 103 Examples include the same monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms as in the chain saturated hydrocarbon group in the above. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, alkyl groups having 1 to 5 carbon atoms are preferred, with methyl and ethyl groups being more preferred, and methyl groups being particularly preferred. The above Ra' 12 and Ra' 13 When the chain saturated hydrocarbon group represented by the formula: is substituted, examples of the substituent include the above-mentioned Ra x5 The same groups as those shown below can be mentioned.

[0103] In formula (a1-r2-4), Ra' 14 Ra' is a hydrocarbon group which may have a substituent. 14 The hydrocarbon group in the formula (I) includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0104] Ra' 14The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0105] Ra' 14 The branched alkyl group in the formula (I) preferably has 3 to 10 carbon atoms, more preferably 3 to 5. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0106] Ra' 14 When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a monocyclic group or a polycyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] 2,6 ]decane, tetracyclododecane, and the like.

[0107] Ra' 14 As the aromatic hydrocarbon group in 104 Among them, the aromatic hydrocarbon groups Ra' are the same as those in 14is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. Ra' 14 Examples of the substituent that may be possessed by Ra include 104 Examples of the substituents include the same as those that may be possessed by the group.

[0108] Ra' in formula (a1-r2-4) 14 When is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. Ra' in formula (a1-r2-4) 14 When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the formula (a1-r2-4) may be any one of the 1st, 2nd, or 9th position of the anthryl group.

[0109] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0110] [ka]

[0111] Secondary alkyl ester-type acid-labile group: R X Examples of the acid-dissociable group in the formula (a1-r-4) include acid-dissociable groups represented by the following general formula (a1-r-4).

[0112] [ka] [In the formula, Ra' 10 Ra' is a hydrocarbon group which may have a substituent. 11a and Ra' 11bEach of Ra' is independently a hydrogen atom, a halogen atom or an alkyl group which may have a substituent. 12 Ra' is a hydrogen atom or a hydrocarbon group which may have a substituent. 10 and Ra' 11a or Ra' 11b and may be bonded to each other to form a ring. 11a or Ra' 11b and Ra' 12 may be bonded to each other to form a ring.

[0113] In the formula, Ra' 10 and Ra' 12 The hydrocarbon group in Ra' 3 The same can be mentioned. In the formula, Ra' 11a and Ra' 11b The alkyl group in Ra' is 1 The same can be mentioned. In the formula, Ra' 10 and Ra' 12 The hydrocarbon group in 11a and Ra' 11b The hydrocarbon group in may have a substituent. Examples of the substituent include a hydroxy group, an alkoxy group, and the above-mentioned Ra x5 etc.

[0114] Ra' 10 and Ra' 11a or Ra' 11b may be bonded to each other to form a ring, which may be a polycyclic ring, a monocyclic ring, an alicyclic ring, or an aromatic ring. The alicyclic ring and aromatic ring may contain a heteroatom. The heteroatom may be contained in a group substituting a hydrogen atom of the alicyclic ring or aromatic ring, or may be contained in a group substituting a carbon atom of the alicyclic ring or aromatic ring.

[0115] Ra' 10 and Ra' 11a or Ra' 11bAmong the above, the ring formed by bonding together is preferably a monocycloalkene, a ring in which some of the carbon atoms of a monocycloalkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), or a monocycloalkadiene, more preferably a cycloalkene having 3 to 6 carbon atoms, and more preferably cyclopentene or cyclohexene.

[0116] Ra' 10 and Ra' 11a or Ra' 11b The ring formed by bonding these may be a fused ring. The fused ring is preferably a fused ring of an aliphatic ring and an aromatic ring, and specific examples thereof include indane, tetralin, and chroman.

[0117] Ra' 10 and Ra' 11a or Ra' 11b The ring formed by bonding together may have a substituent. Examples of the substituent include a hydroxy group, an alkoxy group, and the above-mentioned Ra x5 etc.

[0118] Ra' 11a or Ra' 11b and Ra' 12 and may be bonded to each other to form a ring, and the ring may include Ra' 10 and Ra' 11a or Ra' 11b and the ring formed by bonding with each other are exemplified.

[0119] Specific examples of the group represented by the formula (a1-r-4) are listed below.

[0120] [ka]

[0121] [ka]

[0122] Among the above, R XThe acid-dissociable group in the formula (a01) is R X However, an acid-dissociable group which is bonded to the oxygen atom (—O—) in —C(═O)—O— in formula (a01) via a carbon atom and has a carbon-carbon unsaturated bond formed between the α-position of the carbon atom and the β-position of the carbon atom is preferred. Suitable examples of such acid-dissociable groups include the groups represented by the general formula (a1-r2-2) and (a1-r-4) described above, which are likely to contribute to high sensitivity and high roughness reduction. Furthermore, the group represented by the general formula (a1-r2-2) described above is suitable as an acid-dissociable group that is likely to contribute to high film loss suppression.

[0123] Preferred examples of the structural unit (a01) include structural units represented by the following general formula (a1-1) or (a1-3).

[0124] [ka] [wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 1 is a divalent hydrocarbon group which may have an ether bond. a1 is an integer from 0 to 2. 1 represents an acid-dissociable group represented by the above general formula (a1-r-1), (a1-r-2) or (a1-r-4). 001 represents a single bond or a divalent linking group. 01 is a single bond or a divalent linking group. 01 Rz is an acid-dissociable group represented by the above general formula (a1-r-1), (a1-r-2) or (a1-r-4). 01 is an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxy group, or an alkoxy group. q is an integer of 0 to 3. n is an integer of 0 or more, provided that n≦q×2+4.

[0125] In the formulas (a1-1) and (a1-3), the alkyl group of R having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

[0126] In the formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0127] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0128] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0129] Examples of the aliphatic hydrocarbon group containing a ring in its structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same as the straight-chain aliphatic hydrocarbon group or the branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and specific examples thereof include adamantane, norbornane, isobornane, and tricyclo[5.2.1.0]. 2,6 ]decane, tetracyclododecane, and the like.

[0130] Va 1 In the above, the aliphatic hydrocarbon group containing a ring in its structure may be a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a hetero atom in the ring structure. The cyclic aliphatic hydrocarbon group may have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, or a carbonyl group. In the cyclic aliphatic hydrocarbon group, a methylene group constituting the ring structure may be substituted with a divalent group containing a heteroatom. Examples of the divalent group include a carbonyl group, an ether bond [-O-], an ester bond [-C(=O)-O-], -S-, -S(=O)2-, -S(=O)2-O-, an amide group [-C(=O)-NH-], and an imino group [-NH-]. Specific examples include lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) described below, and -SO2- containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) described below.

[0131] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such aromatic hydrocarbon groups preferably have 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (an arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (an aryl group) has been substituted with an alkylene group (for example, a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group, such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0132] In the formula (a1-1), Ra 1 is preferably an acid-dissociable group represented by the above general formula (a1-r-2) or (a1-r-4), and among these, a group represented by the general formula (a1-r2-2) or an acid-dissociable group represented by the general formula (a1-r-4) is more preferred.

[0133] In the formula (a1-3), Ya 001 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Ya 001is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond. The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. Among these, Ya 001 is more preferably a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, or a single bond, and even more preferably a single bond.

[0134] In the formula (a1-3), Ya 01 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Ya 01 Among the above, Ya is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond. 01 is more preferably a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, or a single bond, and even more preferably a single bond.

[0135] In the formula (a1-3), Rax 01 is preferably an acid-dissociable group represented by the above general formula (a1-r-2) or (a1-r-4), and among these, an acid-dissociable group represented by the general formula (a1-r-2) is more preferred, and a group represented by the general formula (a1-r2-1) is even more preferred.

[0136] In the formula (a1-3), Rz 01The alkyl group, halogenated alkyl group, and alkoxy group in the formula (I) preferably have 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, even more preferably 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The alkyl group, halogenated alkyl group, and alkoxy group may be linear or branched. Rz 01 The halogen atom in Rz is preferably an iodine atom or a bromine atom. 01 The halogen atom of the halogenated alkyl group in is preferably a fluorine atom, an iodine atom, or a bromine atom, and more preferably a fluorine atom. Rz 01 As the alkyl group, an alkoxy group or a hydroxy group is preferred, and a hydroxy group is more preferred.

[0137] In the formula (a1-3), q is an integer of 0 to 3. When q is 0, the structure is a benzene structure; when q is 1, the structure is a naphthalene structure; when q is 2, the structure is an anthracene structure; and when q is 3, the structure is a tetracene structure. In the formula (a1-3), n is an integer of 0 or more, preferably an integer of 0 to 5, more preferably an integer of 0 to 3, and even more preferably 1 or 2. When n is an integer of 2 or more, Rz 01 may be the same as or different from each other. In the formula (a1-3), n≦q×2+4. For example, when q is 1 and the naphthalene structure is formed, all six hydrogen atoms of the naphthalene are Rz 01 In addition, in the naphthalene, Ya 001 , -Ya 01 -C(=O)-O-Rax 01 group, and Rz 01 The substitution position of is not particularly limited.

[0138] Specific examples of the structural unit (a01) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] [ka]

[0148] In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group. Each Rz independently represents a hydrogen atom, an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxy group, or an alkoxy group.

[0149] [ka]

[0150] [ka]

[0151] [ka]

[0152] [ka]

[0153] [ka]

[0154] As the structural unit (a01), a structural unit represented by the aforementioned formula (a1-1) or a structural unit represented by the aforementioned formula (a1-3) is more preferred, as these structural units are more likely to provide improved properties (sensitivity, shape, etc.) in electron beam or EUV lithography. Among these, the acid-dissociable group (Ra 1 , Rax 01 ) are preferably acid-dissociable groups represented by the above general formula (a1-r2-1), general formula (a1-r2-2) or general formula (a1-r-4), respectively. Among these, the acid-dissociable group is R X is preferably an acid-dissociable group that is bonded to the oxygen atom (—O—) in —C(═O)—O— in formula (a01) via a carbon atom and has a carbon-carbon unsaturated bond formed between the α-position of the carbon atom and the β-position of the carbon atom. Suitable examples of such acid-dissociable groups include the groups represented by the general formula (a1-r2-2) and (a1-r-4) described above, which are likely to contribute to high sensitivity and high roughness reduction. Furthermore, the group represented by the general formula (a1-r2-2) described above is suitable as an acid-dissociable group that is likely to contribute to high film loss suppression.

[0155] The structural unit (a01) contained in the component (A1-0) may be of one type, or may be of two or more types. The proportion of the structural unit (a01) in the component (A1-0) relative to the total (100 mol %) of all structural units constituting the component (A1-0) is preferably 25 to 75 mol %, more preferably 40 to 70 mol %, and even more preferably 50 to 65 mol %. By ensuring that the proportion of the structural unit (a01) is at least the lower limit of the preferred range, etching resistance tends to be improved. In addition, lithography properties such as reduced resist pattern roughness tend to be improved. On the other hand, by ensuring that the proportion is at most the upper limit of the preferred range, a balance with other structural units can be achieved, resulting in various improved lithography properties.

[0156] <Constituent unit (a02)> The structural unit (a02) is represented by the following general formula (a02), and is a structural unit that generates an acid upon exposure. In the resist composition of this embodiment, the structural unit (a02) is combined with other compounds so that the acid generated upon exposure is converted to an acid-dissociable group (R X ) or can control the diffusion of acids generated from other compounds.

[0157] [ka] [In formula (a02), R 02 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 02 is a divalent linking group. - is an anionic group. M m+is an onium cation with a valence of m, where m is an integer of 1 or greater.

[0158] [Anion part] In the formula (a02), R 02 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. R 02 The alkyl group having 1 to 5 carbon atoms in the formula (I) is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferred. R 02 As the alkyl group, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, and a hydrogen atom or a methyl group is more preferred from the viewpoint of industrial availability.

[0159] In the formula (a02), L 02 is a divalent linking group. L 02 Examples of the divalent linking group in the formula (a00) include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and a combination thereof. 00 Examples of the divalent hydrocarbon group which may have a substituent, the divalent linking group containing a hetero atom, and combinations thereof are the same as those exemplified in the description of the above. Among the above, L 02is preferably a cyclic aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), an amide bond [-NH-C(=O)-, -C(=O)-NH-], a linear or branched aliphatic hydrocarbon group, a linear or branched fluorinated aliphatic hydrocarbon group, or a combination of two or more thereof; and more preferably a cyclic aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an ester bond [-C(=O)-O-, -OC(=O)-], a linear or branched aliphatic hydrocarbon group, a linear or branched fluorinated aliphatic hydrocarbon group, or a combination of two or more thereof.

[0160] In the formula (a02), Z - is an anionic group. Z - Examples of the anion group in the formula (I) include those having a sulfonate anion structure, a carboxylate anion structure, an imide anion structure, a methide anion structure, a carbonate anion structure, a borate anion structure, a halogen anion structure, a phosphate anion structure, an antimonate anion structure, an arsenate anion structure, and the like. Among these, those having a sulfonate anion structure, a carboxylate anion structure, an imide anion structure, or a methide anion structure are preferred, those having a sulfonate anion structure or a carboxylate anion structure are more preferred, and those having a sulfonate anion structure, i.e., a sulfonate ion, are particularly preferred.

[0161] A preferred example of the structural unit (a02) is a structural unit represented by the following general formula (a02-u).

[0162] [ka] [In the formula, R 02 represents an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 01represents a divalent linking group or a single bond. 01 represents a hydrocarbon group which may have a substituent. 02 represents a divalent linking group or a single bond. 01 represents a fluorinated alkylene group, an alkylene group, or a single bond. 02 and Va 01 R cannot both be single bonds. 03 and R 04 are each independently a fluorinated alkyl group, a fluorine atom, or a hydrogen atom. m+ is an onium cation with a valence of m, where m is an integer of 1 or greater.

[0163] In the formula (a02-u), R 02 The alkyl group having 1 to 5 carbon atoms in the formula (I) is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. R 02 The halogenated alkyl group having 1 to 5 carbon atoms in the formula (I) is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is preferred. R 02 is preferably a hydrogen atom or a methyl group because of industrial availability.

[0164] In the formula (a02-u), Yx 01 The divalent linking group in 02 Examples of the divalent linking group include the same divalent linking groups as those exemplified in the description of the divalent linking group in the above. Yx 01Specific examples of the alkylene group include an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an ether bond (-O-), a linear or branched alkylene group, an arylene group which may have a substituent, any combination thereof, or a single bond. A combination of an arylene group which may have a substituent and an ester bond (-C(=O)-O-), an ester bond (-C(=O)-O-), or a single bond is preferred, and a combination of a phenylene group which may have a substituent and an ester bond (-C(=O)-O-), or an ester bond (-C(=O)-O-).

[0165] In the formula (a02-u), La 01 As the above, L in the formula (a00) 00 Examples of the divalent hydrocarbon group that may have a substituent include the same aliphatic hydrocarbon groups (chain-like aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in the structure) and aromatic hydrocarbon groups as exemplified in the description of the divalent hydrocarbon group that may have a substituent in (1). Among these, aliphatic hydrocarbon groups that contain a ring in the structure and aromatic hydrocarbon groups are preferred, and cyclic aliphatic hydrocarbon groups (groups in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) that may have a substituent and aromatic hydrocarbon groups that may have a substituent are more preferred.

[0166] La 01 The cyclic aliphatic hydrocarbon group in may be a monocyclic alicyclic hydrocarbon group or a polycyclic alicyclic hydrocarbon group, preferably a polycyclic alicyclic hydrocarbon group, more preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and even more preferably a group in which two hydrogen atoms have been removed from adamantane. The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, or a carbonyl group. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0167] La 01 The aromatic hydrocarbon group in is preferably a group in which two hydrogen atoms have been removed from an aromatic hydrocarbon ring or an aromatic heterocycle (an arylene group or a heteroarylene group), more preferably an arylene group, and even more preferably a phenylene group. The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxy group.

[0168] Among the above, La 01 is preferably an aromatic hydrocarbon group which may have a substituent, or a cyclic aliphatic hydrocarbon group which may have a substituent, and more preferably an arylene group which may have a substituent, or a polycyclic alicyclic hydrocarbon group which may have a substituent.

[0169] In the formula (a02-u), Ya 02 The divalent linking group in the formula (a00) is preferably L 00 Examples of the divalent linking group include those similar to the divalent linking group containing a hetero atom in the above formula. Ya 02 is preferably an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), or an oxycarbonyl group (-OC(=O)-), and (La 01 side)-C(=O)-O-(Va 01 It is more preferable that the side is the side.

[0170] In the formula (a02-u), Va 01 The alkylene group in the formula (a00) is preferably L 00The linear or branched aliphatic hydrocarbon groups in Va are the same as those in Va. 01 The fluorinated alkylene group in Va 01 In the above formula, some or all of the hydrogen atoms constituting the alkylene group are substituted with fluorine atoms. Va 01 is preferably a fluorinated alkylene group having 1 to 4 carbon atoms, an alkylene group having 1 to 4 carbon atoms, or a single bond, and particularly preferably a methylene group (-CH2-) or -CH(CF3)-.

[0171] In the formula (a02-u), R 03 and R 04 are each independently a fluorinated alkyl group, a fluorine atom, or a hydrogen atom. 03 and R 04 are each independently preferably a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a hydrogen atom, more preferably a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom, and more preferably a fluorine atom.

[0172] Specific examples of the structural unit (a02) are shown below, but the structural unit (a02) is not limited to these. In each of the formulas shown below, R α represents a trifluoromethyl group, a methyl group, or a hydrogen atom. m+ is an onium cation with a valence of m, where m is an integer of 1 or greater.

[0173] [ka]

[0174] [ka]

[0175] [ka]

[0176] [ka]

[0177] The structural unit (a02) is preferably a structural unit selected from the group consisting of structural units represented by any one of the formulas (a02-u-01) to (a02-u-05), structural units represented by any one of the formulas (a02-u-06) to (a02-u-16), and structural units represented by any one of the formulas (a02-u-17) to (a02-u-23); a structural unit selected from the group consisting of structural units represented by any one of the formulas (a02-u-06) to (a02-u-16), and structural units represented by any one of the formulas (a02-u-17) to (a02-u-23) is more preferred; a structural unit selected from the group consisting of structural units represented by any one of the formulas (a02-u-17) to (a02-u-23) is even more preferred, and a structural unit represented by the formula (a02-u-23) is particularly preferred.

[0178] [Cation part] In the formula (a02), M m+ is an m-valent onium cation, where m is an integer of 1 or greater. m+ Among the onium cations in the formula (I), sulfonium cations and iodonium cations are preferred, and sulfonium cations are more preferred. The preferred cation moiety (M m+ ) 1 / m Examples of the onium cation include the onium cations represented by the following general formulas (ca-1) to (ca-3).

[0179] [ka] [In the formula, R 201 ~R 207 R each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. 201 ~R 203 , R 206 ~R 207may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209 R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. 201 represents -C(=O)- or -C(=O)-O-.]

[0180] In the above general formulas (ca-1) to (ca-3), R 201 ~R 207 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 The alkyl group in the formula (I) is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 Examples of the substituent that may be possessed by include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulas (ca-r-1) to (ca-r-8), respectively. Among these, an alkyl group, a halogen atom, a halogenated alkyl group, and groups represented by the following general formulas (ca-r-1) to (ca-r-8), respectively, are preferred, and a chain alkyl group, an iodine atom, a fluorine atom, a fluorinated alkyl group, and groups represented by the following general formula (ca-r-3), respectively, are more preferred.

[0181] [ka] [In the formula, R' 201are each independently a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0182] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0183] R' 201 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. R' 201 Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R' 201 Specific examples of the aromatic hydrocarbon group in include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0184] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a bridged ring polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0185] Among them, R' 201 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0186] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0187] Also, R' 201 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle, etc. Specific examples include lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) described below, -SO2- containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) described below, and other heterocyclic groups represented by the following chemical formulae (r-hr-1) to (r-hr-16).

[0188] [ka]

[0189] R' 201 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. As the halogen atom as a substituent, a fluorine atom or an iodine atom is preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0190] A chain alkyl group which may have a substituent: R' 201 The chain alkyl group may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0191] An optionally substituted chain alkenyl group: R' 201The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0192] R' 201 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, the above-mentioned R' 201 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0193] R' 201 In addition to those mentioned above, the optionally substituted cyclic group, the optionally substituted chain alkyl group, or the optionally substituted chain alkenyl group also includes the same as the acid-dissociable group represented by formula (a1-r-2) above as the optionally substituted cyclic group or the optionally substituted chain alkyl group.

[0194] Among them, R' 201 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group represented by each of the general formulas (a2-r-1) to (a2-r-7) described below, and an —SO2- containing cyclic group represented by each of the general formulas (b5-r-1) to (b5-r-4) described below are preferred. For example, from the viewpoint of achieving high sensitivity when forming a resist pattern, the aromatic hydrocarbon group may have a substituent, is preferred, is more preferred an aromatic hydrocarbon group having an iodine atom bonded as a substituent, and is particularly preferred a benzene ring having an iodine atom bonded as a substituent.

[0195] In the above general formulas (ca-1) to (ca-3), R 201 ~R 203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they may not contain a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, or a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(the R N is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0196] R 208 ~R 209 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when they are alkyl groups, they may be bonded to each other to form a ring.

[0197] R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in the formula (I) is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210 The -SO2- containing cyclic group in is not particularly limited and any group can be used. Specific examples include groups represented by the following general formulae (b5-r-1) to (b5-r-4), with "-SO2- containing polycyclic groups" being preferred and groups represented by general formula (b5-r-1) being more preferred.

[0198] [ka] [In the formula, Rb' 51 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or an -SO2- containing cyclic group; B" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer of 0 to 2. * represents a bond.

[0199] In the general formulae (b5-r-1) and (b5-r-2), B" represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom. B" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably a methylene group.

[0200] In the general formulae (b5-r-1) to (b5-r-4), Rb' 51are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group, and among these, are preferably each independently a hydrogen atom or a cyano group.

[0201] Specific examples of the groups represented by general formulae (b5-r-1) to (b5-r-4) are listed below, in which "Ac" represents an acetyl group.

[0202] [ka]

[0203] [ka]

[0204] [ka]

[0205] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas.

[0206] [ka]

[0207] [ka]

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

[0209] [ka]

[0210] [ka]

[0211] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the same as R 201 ~R 207 , and R 210 ~R 212 The substituents are the same as those exemplified as the substituents that may be possessed by the group

[0212] [ka]

[0213] [ka]

[0214] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0215] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0216] [ka]

[0217] The cation moiety ((M m+ ) 1 / m) are more preferably cations represented by the above formulas (ca-1) to (ca-3), and particularly preferably cations represented by the above formulas (ca-1-1) to (ca-1-87); diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation. Among these, the cation represented by the formula (ca-1) is preferred, and particularly from the viewpoint of achieving high sensitivity, the preferred cation represented by the formula (ca-1) is one having an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, or a sulfonyl group; or an iodine atom as a substituent, and for example, a cation selected from the group consisting of the cations represented by the above chemical formulas (ca-1-44), (ca-1-71) to (ca-1-84), and (ca-1-85) to (ca-1-87), respectively, is particularly preferred. The number of substituents is, for example, 1 to 6, or may be 2 to 6, or may be 3 to 6, in the entire cation moiety. Among the above, M in the formula (a02) is preferred because it is likely to enhance the effects of reducing sensitivity and roughness. m+ is preferably an m-valent onium cation having a fluorine atom; for example, a cation selected from the group consisting of cations represented by the above chemical formulas (ca-1-71) to (ca-1-75) is more preferred, a cation selected from the group consisting of cations represented by the above chemical formulas (ca-1-72), (ca-1-74), and (ca-1-75) is even more preferred, and a cation selected from the group consisting of cations represented by the above chemical formulas (ca-1-74) and (ca-1-75) is particularly preferred.

[0218] Specific examples of the structural unit (a02) include, but are not limited to, the following. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0219] [ka]

[0220] The structural unit (a02) is preferably a structural unit selected from the group consisting of structural units represented by any one of the above formulas (a02-1) to (a02-6). Because this tends to enhance the sensitivity and roughness reduction effects, a structural unit selected from the group consisting of structural units represented by any one of the above formulas (a02-3) to (a02-5) is more preferred, and a structural unit selected from the group consisting of structural units represented by any one of the above formulas (a02-4) to (a02-5) is even more preferred.

[0221] The structural unit (a02) contained in the component (A1-0) may be of one type, or may be of two or more types. The structural unit (a02) includes M in the above formula (a02). m+ is an m-valent onium cation having a fluorine atom, and Z in the formula (a02) - However, a structural unit that is a sulfonate ion is preferred. The proportion of the structural unit (a02) in the component (A1-0) relative to the total (100 mol %) of all structural units that constitute the component (A1-0) is preferably 1 to 25 mol %, more preferably 2 to 20 mol %, and even more preferably 5 to 15 mol %. The proportion of structural unit (a02) is By adjusting the content to at least the lower limit of the preferred range, etching resistance tends to be improved. In addition, lithography properties such as reduced roughness of the resist pattern tend to be improved. On the other hand, by adjusting the content to at most the upper limit of the preferred range, a balance with other structural units can be achieved, resulting in various improved lithography properties.

[0222] Other structural units The component (A1-0) may be a copolymer that contains the aforementioned structural units (a00), (a01), and (a02), as well as other structural units as necessary. Examples of other structural units include structural units (a1) containing an acid-decomposable group whose polarity increases when acted upon by acid (provided that this does not fall under the category of structural unit (a01)); structural units (a10) represented by general formula (a10-1) described below; structural units (a2) containing a lactone-containing cyclic group; and structural units (a8) derived from compounds represented by general formula (a8-1) described below.

[0223] Regarding the structural unit (a1): The structural unit (a1) is a structural unit (excluding those that fall under the category of the structural unit (a01)) that contains an acid-decomposable group whose polarity increases when acted upon by an acid. Examples of the acid-dissociable group constituting the acid-decomposable group include an "acetal-type acid-dissociable group" and a "tertiary alkyloxycarbonyl acid-dissociable group." Examples of the acetal-type acid-dissociable group include the acid-dissociable group represented by the above general formula (a1-r-1). Examples of the tertiary alkyloxycarbonyl acid-dissociable group include acid-dissociable groups represented by the following general formula (a1-r-3).

[0224] [ka] [In the formula, Ra' 7 ~Ra' 9 are each alkyl groups.

[0225] In formula (a1-r-3), Ra' 7 ~Ra' 9 are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms. The total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0226] Examples of the structural unit (a1) include a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a portion of the hydrogen atoms of the hydroxyl groups are protected with a substituent containing the acid-decomposable group. Of the above, the structural unit (a1) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. Specific examples of such structural units (a1) include structural units represented by the following general formula (a1-2).

[0227] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 1 is n a2 + is a monovalent hydrocarbon group. n a2 is an integer between 1 and 3. 2 is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0228] In the formula (a1-2), the alkyl group of 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group of 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group of 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group of 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

[0229] In the formula (a1-2), Wa1 In, n a2 The monovalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity and may be saturated or unsaturated, but is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in their structure, and groups that combine linear or branched aliphatic hydrocarbon groups with aliphatic hydrocarbon groups containing a ring in their structure. The n a2 The +1 valence is preferably 2 to 4, more preferably 2 or 3. In the formula (a1-2), Ra 2 is preferably an acid-dissociable group represented by the above general formula (a1-r-1).

[0230] When the component (A1-0) contains the structural unit (a1), the proportion of the structural unit (a1) in the component (A1-0) is preferably no more than 20 mol % relative to the total (100 mol %) of all structural units constituting the component (A1-0). By having the structural unit (a1) in an amount at most the upper limit of the aforementioned preferred range, it becomes easier to form a resist pattern that exhibits various excellent lithography properties, such as high sensitivity, high resolution, reduced roughness, and suppressed film loss.

[0231] Regarding the structural unit (a10): The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0232] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.] x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1.]

[0233] In the formula (a10-1), R is the same as R in the formulae (a1-1) and (a1-3). R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferable, a hydrogen atom or a methyl group is still more preferable, and a hydrogen atom is particularly preferable.

[0234] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya x1 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Ya x1 The divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom in the formula (a00) are described above in detail in the description of L 00 The explanations for the divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom in the above are the same as those for the divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom. Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond or an ester bond [-C(=O)-O-, -OC(=O)-].

[0235] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in the formula (n) is an aromatic ring which may have a substituent. ax1Examples of the aromatic ring include groups in which 4n+1) hydrogen atoms have been removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Also, Wa x1 The aromatic hydrocarbon group in (n) is selected from aromatic compounds containing an aromatic ring which may have two or more substituents (for example, biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1 As examples, benzene, naphthalene, anthracene, or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed from benzene or naphthalene is preferred. ax1 A group obtained by removing (n +1) hydrogen atoms from benzene is more preferred. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0236] Wa x1 The aromatic hydrocarbon group in may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. Wa x1 The aromatic hydrocarbon group in the formula (I) preferably does not have a substituent.

[0237] 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, further preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0238] Specific examples of the structural unit (a10) represented by the formula (a10-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0239] [ka]

[0240] [ka]

[0241] [ka]

[0242] The structural unit (a10) that the component (A1-0) can have may be of one type, or two or more types. The component (A1-0) may or may not contain the structural unit (a10). When the component (A1-0) contains the structural unit (a10), the proportion of the structural unit (a10) in the component (A1-0) is preferably no more than 20 mol % relative to the total (100 mol %) of all structural units constituting the component (A1-0). By containing the structural unit (a10) in an amount no greater than the upper limit of the above-mentioned preferred range, sensitivity tends to be further improved.

[0243] Regarding the structural unit (a2): The component (A1-0) may further include a structural unit (a2) that contains a lactone-containing cyclic group (provided that this does not include units that correspond to the structural unit (a01) or the structural unit (a1)). The lactone-containing cyclic group of the structural unit (a2) is effective in improving the adhesion of the resist film to the substrate when the component (A1-0) is used to form a resist film. Furthermore, the presence of the structural unit (a2) results in favorable lithography properties, for example, by appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0244] A "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and a group consisting of only a lactone ring is called a monocyclic group. If a group further contains other ring structures, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any suitable group can be used. Specific examples include groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0245] [ka] [In the formula, Ra' 21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom; n' is an integer of 0 to 2, and m' is 0 or 1. * represents a bond (the same applies hereinafter).

[0246] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. Ra' 21 The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the alkoxy group in the formula (1) is preferably linear or branched. 21 Examples of the alkyl group include a group in which the alkyl groups mentioned above are linked to an oxygen atom (—O—). Ra' 21 The halogen atom in is preferably a fluorine atom. Ra' 21 The halogenated alkyl group in the formula Ra' is 21 Examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0247] Ra' 21 In the -COOR" and -OC(=O)R" groups, R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, tricycloalkane, or tetracycloalkane. More specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples of the lactone-containing cyclic group in R″ include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) above. Ra' 21 The hydroxyalkyl group in the formula (I) preferably has 1 to 6 carbon atoms, and specifically, the hydroxyalkyl group in the formula (I) is preferably a hydroxyalkyl group having 1 to 6 carbon atoms. 21 and a group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0248] Ra' 21 Among the above, each of the groups is preferably independently a hydrogen atom or a cyano group.

[0249] In the general formulae (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms for A" is preferably a straight-chain or branched-chain alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, and -CH2-S-CH2-. A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0250] Specific examples of the groups represented by the general formulae (a2-r-1) to (a2-r-7) are listed below.

[0251] [ka]

[0252] [ka]

[0253] Of the structural units (a2), structural units derived from acrylate esters in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent are particularly preferred. Such a structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0254] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.] 21 is a single bond or a divalent linking group. 21is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, where R' represents a hydrogen atom or a methyl group. 21 If -O-, Ya 21 does not become -CO-. Ra 21 is a lactone-containing cyclic group.

[0255] In the formula (a2-1), R is the same as R in the formulae (a1-1) and (a1-3). R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferred.

[0256] In the formula (a2-1), Ya 21 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Ya 21 The divalent linking group in the formula (a00) is preferably L 00 The explanations for the divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom in the above are the same as those for the divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom. Ya 21 is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. In the formula (a2-1), Ya 21 is a single bond, and La 21 is preferably —COO— or —OCO—.

[0257] In the above formula (a2-1), Ra 21 is a lactone-containing cyclic group. Ra 21 Suitable examples of the lactone-containing cyclic group in the formula (a2-r-1) include the groups represented by the general formulae (a2-r-1) to (a2-r-7) described above.

[0258] The structural unit (a2) that the component (A1-0) can have may be of one type, or two or more types. The component (A1-0) may or may not contain the structural unit (a2). When the component (A1-0) contains the structural unit (a2), the proportion of the structural unit (a2) relative to the total (100 mol%) of all structural units constituting the component (A1-0) is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 5 to 15 mol%. When the proportion of the structural unit (a2) is at least as great as the preferred lower limit, the effects achieved by including the structural unit (a2) can be fully obtained due to the effects described above. When the proportion of the structural unit (a2) is at most the upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0259] Regarding the structural unit (a8): The structural unit (a8) is a structural unit derived from a compound represented by the following general formula (a8-1).

[0260] [ka] [In the formula, W 2 is a polymerizable group-containing group. x2 is a single bond or (n ax2 +1)valent linking group. x2 and W 2 R may form a condensed ring. 1 R is a fluorinated alkyl group having 1 to 12 carbon atoms. 2 R is a hydrogen atom or an organic group having 1 to 12 carbon atoms which may have a fluorine atom. 2 and Ya x2 may be bonded to each other to form a ring structure. ax2 is an integer between 1 and 3.

[0261] W 2The "polymerizable group" in the polymerizable group-containing group is a group that enables a compound having a polymerizable group to be polymerized by radical polymerization or the like, and refers to a group that contains a multiple bond between carbon atoms, such as an ethylenic double bond.

[0262] The polymerizable group-containing group may be a group consisting of only a polymerizable group, or may be a group consisting of a polymerizable group and a group other than the polymerizable group. Examples of the group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a heteroatom. Examples of the polymerizable group-containing group include a group represented by the chemical formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 A group represented by the formula - is preferred. In this chemical formula, R X11 , R X12 and R X13 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya x0 is a single bond or a divalent linking group.

[0263] Ya x2 and W 2 The fused ring formed by 2 Polymerizable group of the site and Ya x2 and W 2 Other groups than the polymerizable group at the Ya site x2 and a fused ring formed by Ya x2 and W 2 The fused ring formed by these may have a substituent.

[0264] Specific examples of the structural unit (a8) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0265] [ka]

[0266] The structural unit (a8) that the component (A1-0) can have may be of one type, or two or more types. The component (A1-0) may or may not contain the structural unit (a8). When the component (A1-0) contains the structural unit (a8), the proportion of the structural unit (a8) in the component (A1-0) is preferably 30 mol % or less, more preferably 0 to 20 mol %, and even more preferably 0 to 10 mol %, relative to the total (100 mol %) of all structural units constituting the component (A1-0).

[0267] In the resist composition of this embodiment, the resin component (component (A1)) whose solubility in a developer changes under the action of acid contains a copolymer (component (A1-0)) having the structural unit (a00), the structural unit (a01), and the structural unit (a02). A preferred example of the component (A1-0) is a copolymer consisting only of repeating units of the structural unit (a00), the structural unit (a01), and the structural unit (a02). Based on the total (100 mol%) of all structural units constituting the component (A1-0), the proportion of structural unit (a00) within the component (A1-0) is preferably 5 to 45 mol%, more preferably 10 to 40 mol%, and even more preferably 20 to 35 mol%; the proportion of structural unit (a01) within the component (A1-0) is preferably 30 to 70 mol%, more preferably 40 to 70 mol%, and even more preferably 50 to 65 mol%; and the proportion of structural unit (a02) within the component (A1-0) is preferably 1 to 25 mol%, more preferably 2 to 20 mol%, and even more preferably 5 to 15 mol%. However, the total amount of the structural units (a00), (a01), and (a02) does not exceed 100 mol %.

[0268] The component (A1-0) can be produced by dissolving the monomers that derive the respective structural units in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the solution and polymerizing the resulting mixture. During polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH may be used in combination to introduce a -C(CF3)2-OH group to the terminal. Copolymers incorporating hydroxyalkyl groups in which some of the alkyl group's hydrogen atoms have been substituted with fluorine atoms are effective in reducing development defects and LER (line edge roughness: unevenness on the line sidewalls).

[0269] The weight-average molecular weight (Mw) of component (A1-0) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. When the Mw of component (A1-0) is equal to or less than the preferred upper limit of this range, the component will have sufficient solubility in a resist solvent for use as a resist, while when the Mw is equal to or greater than the preferred lower limit of this range, the component will have good dry etching resistance and the cross-sectional shape of the resist pattern. The dispersity (Mw / Mn) of the component (A1-0) is not particularly limited, but is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.0, where Mn represents the number average molecular weight.

[0270] The component (A1-0) contained in the resist composition may use either a single type of compound, or a combination of two or more types of compounds. The resist composition of this embodiment may also use, as the component (A1), a resin component (component (A1-1)) that does not fall under the category of the component (A1-0) and whose solubility in a developer changes upon the action of acid. The proportion of component (A1-0) within component (A1), relative to the total mass of component (A1), is preferably 25 mass% or more, more preferably 50 mass% or more, even more preferably 75 mass% or more, and may even be 100 mass%. A proportion of 25 mass% or more facilitates the formation of a resist pattern that exhibits excellent lithography properties, such as high sensitivity, high resolution, reduced roughness, and suppressed film loss.

[0271] About the base component (A2) The resist composition of this embodiment may also use, as the component (A), a base component that does not fall under the category of the component (A1) (hereafter referred to as “component (A2)”). There are no particular restrictions on the component (A2), and it can be selected from the many conventional base components for chemically amplified resist compositions. The component (A2) may be a high molecular weight compound or a low molecular weight compound, and may be used alone or in combination of two or more types.

[0272] The amount of the component (A) in the resist composition of this embodiment may be adjusted depending on factors such as the thickness of the resist film to be formed.

[0273] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the component (A). Examples of other components include the following components (B), (D), (E), (F), and (S).

[0274] <Component (B): Acid Generator Component> The resist composition of this embodiment may further contain an acid generator component (B) that generates an acid upon exposure. There are no particular restrictions on the component (B), and any of the acid generators that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisaryl sulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, nitrobenzyl sulfonate-based acid generators, imino sulfonate-based acid generators, and disulfone-based acid generators.

[0275] Examples of the onium salt acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0276] Examples of the onium salt acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0277] [ka] [In the formula, R 101 and R 104 ~R 108 R each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 104 and R 105 R may be bonded to each other to form a ring structure. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 101 is a divalent linking group containing an oxygen atom or a single bond. 101 ~V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, provided that Y 101 and V 101 cannot be a single bond at the same time. 101 ~L 102 are each independently a single bond or an oxygen atom. 103 ~L 105 are each independently a single bond, —CO— or —SO2—; m is an integer of 1 or more; and M' m+ is an m-valent onium cation.

[0278] {anion part} Anion in component (b-1) In formula (b-1), R 101 represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0279] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group is preferably saturated.

[0280] R 101 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R 101 Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R 101 Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0281] R 101 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, the polycycloalkane includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0], and the like. 2,6 More preferred are polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as decane and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton.

[0282] Among them, R 101 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0283] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0284] Also, R 101 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle, etc. Specific examples include the lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, the —SO—-containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) above, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) above.

[0285] R 101Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. As the halogen atom as a substituent, a fluorine atom, a bromine atom, or an iodine atom is preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0286] R 101 The cyclic hydrocarbon group in may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a polycyclic skeleton of a bridged ring system to which one or more aromatic rings are fused. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. 101 Specific examples of the fused cyclic group in the formula (b-1) include those represented by the following formulas (r-br-1) to (r-br-2). 101 represents a bond bonded to

[0287] [ka]

[0288] R 101 Examples of the substituent that the fused cyclic group in the formula (I) may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused cyclic group are the same as those described above in R 101 Examples of the substituents for the cyclic group in the formula (I) include the same as those listed above. Examples of the aromatic hydrocarbon group as the substituent of the fused ring group include a group in which one hydrogen atom has been removed from an aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of the alicyclic hydrocarbon group as a substituent of the fused ring group include groups in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane; 2,6 ] groups in which one hydrogen atom has been removed from a polycycloalkane such as decane, tetracyclododecane, or tetracyclododecane; lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above; —SO2- containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) above; and heterocyclic groups represented by the formulae (r-hr-7) to (r-hr-16) above.

[0289] A chain alkyl group which may have a substituent: R 101 The chain alkyl group may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0290] An optionally substituted chain alkenyl group: R 101 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0291] R 101 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the above-mentioned R 101 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0292] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 is a divalent linking group containing an oxygen atom, 101may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of the divalent linking group containing an oxygen atom include linking groups represented by the following general formulas (y-al-1) to (y-al-7): In the following general formulas (y-al-1) to (y-al-7), R 101 The bond to V' in the following general formulas (y-al-1) to (y-al-7) is 101 is.

[0293] [ka] [In the formula, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0294] V' 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0295] V' 101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. Also, V' 101 or V' 102 In the formula (a1-r-1), some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by Ra' in the formula (a1-r-1). 3 A divalent group obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group) of the above is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0296] In formula (b-1), V 101 is a single bond, an alkylene group, or a fluorinated alkylene group. 101 is preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0297] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0298] Specific examples of the anion moiety represented by the formula (b-1) include, for example, Y 101 When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; 101 When is a divalent linking group containing an oxygen atom, examples of the anions include those represented by any of the following formulae (an-1) to (an-3).

[0299] [ka] [In the formula, R” 101 R" 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), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a chain alkyl group which may have a substituent, or an aromatic cyclic group which may have a substituent. 102 R" is an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the formula (r-br-1) or (r-br-2) above, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1), (a2-r-3) to (a2-r-7) above, or an -SO2- containing cyclic group represented by each of the general formulae (b5-r-1) to (b5-r-4) above. 103 V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. 101 is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; each v" is independently an integer of 0 to 3, each q" is independently an integer of 0 to 20, and n" is 0 or 1.

[0300] R” 101 , R” 102 and R” 103 The aliphatic cyclic group which may have a substituent is represented by R 101The substituent is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in the formula (b-1). 101 Examples of the substituents that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1).

[0301] R” 101 and R” 103 The aromatic cyclic group which may have a substituent in the formula (b-1) is R 101 The substituent is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the formula (b-1). 101 Examples of the substituents that may substitute the aromatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0302] R” 101 The chain alkyl group which may have a substituent in the formula (b-1) is R 101 The alkyl group is preferably one of the groups exemplified as the chain alkyl group in the above formula. R” 103 The chain alkenyl group which may have a substituent is R 101 Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0303] Anion in component (b-2) In formula (b-2), R 104 , R 105 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is represented by R 101 However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105 is preferably a chain alkyl group which may have a substituent, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. 104 , R 105 The number of carbon atoms in the chain alkyl group of R is preferably as small as possible within the above range of carbon atoms, for reasons such as good solubility in resist solvents. 104 , R 105 In the chain alkyl group, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the improved transparency to high-energy light of 250 nm or less and electron beams, which is preferable. The proportion of fluorine atoms in the chain alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-1). 101 The same can be mentioned. In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0304] Anion in component (b-3) In formula (b-3), R 106 ~R 108 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is represented by R 101 The same can be mentioned. In formula (b-3), L 103 ~L 105 are each independently a single bond, —CO— or —SO2—.

[0305] Among the above, the anion moiety of the component (B) is preferably the anion in the component (b-1), and more preferably the anion represented by the above formula (an-1).

[0306] {cation part} In the formula (b-1), formula (b-2), and formula (b-3), M' m+ represents an m-valent onium cation. Among these, sulfonium cation and iodonium cation are preferred. m is an integer of 1 or more.

[0307] The cation moiety of component (B) is preferably a sulfonium cation, more preferably a cation represented by each of the formulas (ca-1) to (ca-3), still more preferably a cation represented by the formula (ca-1), and particularly preferably a cation represented by each of the formulas (ca-1-1) to (ca-1-87).

[0308] In the resist composition of this embodiment, the component (B) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (B), the amount of the component (B) within the resist composition is preferably less than 50 parts by mass, more preferably 5 to 40 parts by mass, and even more preferably 10 to 40 parts by mass, per 100 parts by mass of the component (A1-0). By ensuring that the amount of component (B) falls within this preferred range, it becomes easier to obtain a homogeneous solution when the individual components of the resist composition are dissolved in an organic solvent, and the storage stability of the resist composition becomes excellent, which is advantageous.

[0309] <Component (D): Base Component> The resist composition of this embodiment may contain, in addition to the component (A), a base component (component (D)) that traps the acid generated upon exposure (i.e., controls the diffusion of the acid). The component (D) functions as a quencher (acid diffusion controller) that traps the acid generated in the resist composition upon exposure. Examples of the component (D) include a photodegradable base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure and loses its acid diffusion controllability, and a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of component (D1). Among these, the photodegradable base (component (D1)) is preferred because it is likely to enhance all of the properties of high sensitivity, reduced roughness, and suppression of coating defects. The compounds exemplified below as component (D1) may be used as the acid generator component (component (B)) described above, depending on the combination with other compounds.

[0310] Regarding component (D1) The component (D1) is not particularly limited as long as it decomposes upon exposure to light and loses its acid diffusion controllability, and is preferably one or more compounds selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"). The components (d1-1) to (d1-3) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion control properties (basicity), but act as quenchers in the unexposed areas of the resist film.

[0311] [ka] [In the formula, Rd 1 ~Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 2 In this case, no fluorine atom is bonded to the carbon atom adjacent to the S atom. 1 is a single bond or a divalent linking group; m is an integer of 1 or more; M m+ are each independently an m-valent onium cation.

[0312] {(d1-1) component} Anion part In formula (d1-1), Rd 1 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of the R' 201 The same can be mentioned. Among these, Rd 1 is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by the above general formulas (a2-r-1) to (a2-r-7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be via an alkylene group, and in this case, the substituent is preferably a linking group represented by the above formulas (y-al-1) to (y-al-5). Note that Rd 1 In the case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group has a linking group represented by the above general formulas (y-al-1) to (y-al-7) as a substituent, in the above general formulas (y-al-1) to (y-al-7), Rd 1 The carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the formula (y-al-1) to (y-al-7) is bonded to V' 101 is. Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and another ring structure). Examples of the aliphatic cyclic group include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 It is more preferable that the cycloalkane is a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as decane or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include straight-chain alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched-chain alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0313] When the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, and nitrogen atoms.

[0314] Preferred examples of the anion moiety of the component (d1-1) are shown below.

[0315] [ka]

[0316] Cation part In formula (d1-1), M m+ is an m-valent onium cation. M m+ Suitable onium cations include those similar to those represented by the general formulae (ca-1) to (ca-3), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the general formulae (ca-1-1) to (ca-1-87) being even more preferred. The component (d1-1) may be used alone or in combination of two or more.

[0317] {(d1-2) component} Anion part In formula (d1-2), Rd 2 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and R' 201 The same can be mentioned. However, Rd 2 In this case, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not fluorinated), which makes the anion of component (d1-2) an appropriately weak acid anion, thereby improving the quenching ability of component (D). Road 2 The alkyl group is preferably a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent, and more preferably an aliphatic cyclic group which may have a substituent.

[0318] The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. Examples of the aliphatic cyclic group include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 ] a group (which may have a substituent) in which one or more hydrogen atoms have been removed from decane, tetracyclododecane, or the like; and a group in which one or more hydrogen atoms have been removed from camphor is more preferred.

[0319] Road 2 The hydrocarbon group may have a substituent, and the substituent may be Rd 1 Examples of the substituents include the same as those that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0320] Preferred examples of the anion moiety of the component (d1-2) are shown below.

[0321] [ka]

[0322] Cation part In formula (d1-2), M m+ is an m-valent onium cation, and M in the formula (d1-1) m+ is the same as: The component (d1-2) may be used alone or in combination of two or more.

[0323] {(d1-3) component} Anion part In formula (d1-3), Rd 3 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and 201 The Rd is preferably a fluorine atom-containing cyclic group, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferred, and the Rd 1 The same fluorinated alkyl groups as those mentioned above are more preferred.

[0324] In formula (d1-3), Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and R' 201 The same can be mentioned. Among these, alkyl groups, alkoxy groups, alkenyl groups and cyclic groups which may have a substituent are preferred. Road 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. 4 A portion of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Road 4The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0325] Road 4 The alkenyl group in R' 201 Examples include the same alkenyl groups as those in the above, and vinyl, propenyl (allyl), 1-methylpropenyl, and 2-methylpropenyl groups are preferred. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0326] Road 4 The cyclic group in the formula (I) is the same as the R' 201 Examples of the cyclic groups include cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 ] An alicyclic group in which one or more hydrogen atoms have been removed from a cycloalkane such as decane or tetracyclododecane, or an aromatic group such as a phenyl group or naphthyl group is preferred. 4 When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in excellent lithography properties. 4 When is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency, and exhibits favorable sensitivity and lithography properties.

[0327] In formula (d1-3), Yd 1 is a single bond or a divalent linking group. Yd 1 The divalent linking group in is not particularly limited, but examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, and a divalent linking group containing a hetero atom. 21Examples of the divalent linking group include the same divalent hydrocarbon groups which may have a substituent and divalent linking groups containing a hetero atom as those mentioned in the description of the divalent linking group in the above. Yd 1 is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and further preferably a methylene group or an ethylene group.

[0328] Preferred examples of the anion moiety of the component (d1-3) are shown below.

[0329] [ka]

[0330] [ka]

[0331] Cation part In formula (d1-3), M m+ is an m-valent onium cation, and M in the formula (d1-1) m+ is the same as: The component (d1-3) may be used alone or in combination of two or more.

[0332] The component (D1) may be any one of the components (d1-1) to (d1-3) above, or a combination of two or more of them. When the resist composition contains the component (D1), the amount of the component (D1) within the resist composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 12 parts by mass, and even more preferably 2 to 10 parts by mass, per 100 parts by mass of the component (A1-0).

[0333] The component (D1) preferably contains the component (d1-1) above. The content of the component (d1-1) in the entire component (D1) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The component (D1) may consist solely of the compound component (d1-1).

[0334] Manufacturing method of component (D1): The method for producing the components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods. The method for producing component (d1-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0335] Regarding component (D2) The component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the component (D1) above. The component (D2) is not particularly limited as long as it acts as an acid diffusion controller and does not fall under the category of component (D1), and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are particularly preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms. Examples of aliphatic amines include amines in which at least one hydrogen atom of ammonia NH3 has been substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), and cyclic amines. Specific examples of alkylamines and alkyl alcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0336] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. The aliphatic polycyclic amine is preferably one having 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0337] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, and triethanolamine triacetate, with triethanolamine triacetate being preferred.

[0338] Furthermore, an aromatic amine may be used as the component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, 2,6-di-tert-butylpyridine, and 2,6-di-tert-butylpyridine.

[0339] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), the amount of the component (D2) within the resist composition is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A1-0). By ensuring this range, the resist pattern shape and stability over time during storage can be improved.

[0340] <Component (E): At least one compound selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and derivatives thereof> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, and phosphorus oxo acids and derivatives thereof (hereafter referred to as "component (E)") for the purposes of preventing sensitivity degradation and improving the resist pattern shape and stability over time after exposure. Specific examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, with salicylic acid being preferred. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred.

[0341] In the resist composition of this embodiment, the component (E) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (E), the amount of the component (E) per 100 parts by mass of the component (A1-0) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass. By ensuring that the amount is within this range, lithography properties are further improved.

[0342] <(F) Component: Fluorine additive component> The resist composition of this embodiment may contain a fluorine additive component (hereafter referred to as "component (F)") as a hydrophobic resin. Component (F) is used to impart water repellency to the resist film, and when used as a resin separate from component (A), it can improve lithography properties. As the component (F), for example, the fluorine-containing polymer compounds described in JP-A Nos. 2010-002870, 2010-032994, 2010-277043, 2011-13569, and 2011-128226 can be used. More specifically, the component (F) may be a polymer having a structural unit (f1) represented by the following general formula (f1-1): This polymer is preferably a polymer (homopolymer) consisting solely of the structural unit (f1) represented by the following formula (f1-1), a copolymer of the structural unit (f1) with the structural unit (a01), or a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a01), with the copolymer of the structural unit (f1) and the structural unit (a01) being more preferred. Here, the structural unit (a01) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl(meth)acrylate or a structural unit derived from 1-methyl-1-adamantyl(meth)acrylate, and more preferably a structural unit derived from 1-ethyl-1-cyclooctyl(meth)acrylate.

[0343] [ka] [wherein R is the same as defined above, and Rf 102 and Rf 103 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Rf 102 and Rf 103 may be the same or different, nf1 is an integer of 0 to 5, and Rf 101 is an organic group containing a fluorine atom.

[0344] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as defined above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf 102 and Rf 103 The halogen atom in Rf is preferably a fluorine atom. 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms in Rf include the same alkyl groups having 1 to 5 carbon atoms as those in R, and a methyl group or an ethyl group is preferred. 102 and Rf 103 Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is preferred. Among these, Rf 102 and Rf 103 is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom. In formula (f1-1), nf1 represents an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0345] In formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The fluorine atom-containing hydrocarbon group may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. Furthermore, in the fluorine atom-containing hydrocarbon group, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more, because this increases the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101 is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, or -CH2-CH2-CF2-CF2-CF2-CF3.

[0346] The weight-average molecular weight (Mw) of component (F) (based on polystyrene standards measured by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. When the Mw is below the upper limit of this range, the component has sufficient solubility in a resist solvent for use as a resist, and when the Mw is above the lower limit of this range, the resulting resist film has good water repellency. The dispersity (Mw / Mn) of the component (F) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and most preferably from 1.0 to 2.5.

[0347] In the resist composition of this embodiment, the component (F) may be used alone, or in combination of two or more different compounds. When the resist composition contains the component (F), the amount of the component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the component (A1-0).

[0348] <Component (S): Organic solvent component> The resist composition of this embodiment can be produced by dissolving the resist materials in an organic solvent component (hereafter referred to as “component (S)”). The component (S) can be any solvent that is capable of dissolving the individual components used and forming a homogeneous solution, and any solvent that is appropriately selected from among those known to be conventionally used as solvents for chemically amplified resist compositions can be used. In the resist composition of this embodiment, the component (S) may be used alone or as a mixed solvent of two or more types, with propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, ethyl lactate (EL), and cyclohexanone being preferred.

[0349] Furthermore, a mixed solvent of PGMEA and a polar solvent is also preferred as component (S), and the blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and the polar solvent, etc. The component (S) is also preferably a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone, in which case the mass ratio of the former to the latter is preferably 70:30 to 95:5. There are no particular restrictions on the amount of component (S) used, and it is set appropriately depending on the coating film thickness so as to provide a concentration that allows application to a substrate, etc. Generally, the component (S) is used so that the solids concentration of the resist composition falls within the range of 0.1 to 20 mass %, and preferably 0.2 to 15 mass %.

[0350] The resist composition of this embodiment may further contain, if desired, compatible additives such as an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, or a dye.

[0351] The resist composition of this embodiment may be prepared by dissolving the resist material in component (S) and then removing impurities using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous film, a filter made of a polyamideimide porous film, or a filter made of a polyimide porous film and a polyamideimide porous film. Examples of such polyimide porous films and polyamideimide porous films include those described in JP 2016-155121 A.

[0352] As explained above, the resist composition of this embodiment contains, as a base component, a copolymer that has a structural unit represented by general formula (a00) (structural unit (a00)), a structural unit represented by general formula (a01) (structural unit (a01)), and a structural unit represented by general formula (a02) that generates acid upon exposure (structural unit (a02)). The structural unit (a00) has a maleimide structure as a polymerizable group, which has high solubility in a developer, and also functions as a proton source. By incorporating the structural unit (a02), which generates acid upon exposure, into the resin that is the base component, acid is more easily generated uniformly within the resist film. Furthermore, the content of low-molecular-weight components (e.g., component (B)) can be reduced, thereby suppressing dissolution of the unexposed areas of the resist film. Furthermore, the resin, which is the base material component, is provided with an acid-dissociable group (R X Since the structural unit (a01) containing the maleimide structure is bonded to the structural unit (a02), the reaction tends to proceed uniformly throughout the resist film. In addition, since the structural unit (a00) having a highly rigid maleimide structure and the structural unit (a02) that generates acid upon exposure are bonded to the resin that is the base component, the diffusion of the acid generated upon exposure is easily controlled. Due to these synergistic effects, the resist composition of this embodiment achieves high sensitivity during resist pattern formation, and is effective in reducing roughness and suppressing film loss.

[0353] (Method for forming a resist pattern) A method for forming a resist pattern according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition according to the first aspect of the present invention, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. One embodiment of the resist pattern forming method is a resist pattern forming method carried out as follows.

[0354] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and then baked (post-apply bake (PAB)) at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an ArF exposure device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with an electron beam without using a mask pattern, and then baked (post-exposure bake (PEB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150°C. Next, the resist film is developed using an alkaline developer in the case of an alkaline development process, or a developer containing an organic solvent (organic developer) in the case of a solvent development process.

[0355] After the development process, a rinse process is preferably carried out. In the case of an alkaline development process, the rinse process is preferably a water rinse using pure water, and in the case of a solvent development process, it is preferable to use a rinse solution containing an organic solvent. In the case of a solvent development process, the developing treatment or rinsing treatment may be followed by a treatment of removing the developing solution or rinsing solution adhering to the pattern using a supercritical fluid. After the development treatment or rinsing treatment, the film is dried. In some cases, a baking treatment (post-baking) may be performed after the development treatment.

[0356] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, examples include silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold.

[0357] The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays can be used. The method for forming a resist pattern of this embodiment is particularly useful for a method in which the resist film is exposed to EUV (extreme ultraviolet) or EB (electron beam) in the step of exposing the resist film.

[0358] The exposure method for the resist film may be a normal exposure (dry exposure) carried out in air or an inert gas such as nitrogen, or may be liquid immersion lithography. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure device is filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. The immersion medium is preferably a solvent having a refractive index greater than that of air and less than that of the resist film to be exposed, such as water, a fluorine-based inert liquid, a silicon-based solvent, or a hydrocarbon-based solvent. As the immersion medium, water is preferably used.

[0359] The alkaline developer used in the development treatment in the alkaline development process may be, for example, a 0.1 to 10 mass % aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent capable of dissolving component (A) (component (A) before exposure), and may be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0360] Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0361] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0362] The organic developer may contain known additives as needed. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants.

[0363] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), or a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0364] The organic solvent contained in the rinse solution used in the rinsing treatment after development in the solvent development process can be selected appropriately from the organic solvents listed above as organic solvents used in the organic developer, so long as it does not easily dissolve the resist pattern. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used alone or in combination of two or more, and may be used in combination with other organic solvents or water.

[0365] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method, such as a method of continuously applying the rinse solution onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse solution for a certain period of time (dipping method), or a method of spraying the rinse solution onto the surface of the support (spray method).

[0366] As described above, according to the method of forming a resist pattern of this embodiment, the resist composition described above is used, thereby achieving high sensitivity in resist pattern formation, and being highly effective in reducing roughness and suppressing film loss, making it possible to form a resist pattern with a favorable shape.

[0367] The resist composition of the above-described embodiment and the various materials used in the resist pattern formation method of the above-described embodiment (e.g., resist solvent, developer, rinse, anti-reflective coating composition, top coat composition, etc.) preferably do not contain impurities such as metals, halogen-containing metal salts, acids, alkalis, or components containing sulfur or phosphorus atoms. Examples of metal-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, and salts thereof. The impurity content of these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0368] (copolymer) A third aspect of the present invention is a copolymer having a structural unit represented by the following general formula (a00), a structural unit represented by the following general formula (a01), and a structural unit represented by the following general formula (a02) that generates acid upon exposure.

[0369] [ka] [In formula (a00), R 0a and R 0b are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 00 is a divalent linking group or a single bond. Ar is an aromatic group which may have a substituent. The substituent which this aromatic group may have is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, an aryl group, an alkoxy group, and a hydroxy group. 01 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 01 is a divalent linking group or a single bond. Xis an acid-dissociable group. 02 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 02 is a divalent linking group. - is an anionic group. M m+ is an onium cation with a valence of m, where m is an integer of 1 or greater.

[0370] The structural unit represented by general formula (a00) is the same as the structural unit (a00) described above in the resist composition. Ar is preferably an aromatic group having an iodine atom as a substituent. Preferred examples of the structural unit (a00) include structural units represented by the above general formula (a00-u).

[0371] The structural unit represented by general formula (a01) is the same as the structural unit (a01) described above in the resist composition. X is preferably an acid-dissociable group that is bonded to the oxygen atom (-O-) in -C(=O)-O- in formula (a01) via a carbon atom and has a carbon-carbon unsaturated bond formed between the α-position of said carbon atom and the β-position of said carbon atom. Preferred examples of the structural unit (a01) include structural units represented by general formula (a1-1) or (a1-3) above.

[0372] The structural unit represented by general formula (a02) that generates acid upon exposure is the same as the structural unit (a02) described above in the resist composition. m+ is preferably an m-valent onium cation having a fluorine atom. - is preferably a sulfonate ion. Preferred examples of the structural unit (a02) include structural units represented by the above general formula (a02-u).

[0373] The copolymer related to the third aspect is the same as the copolymer (component (A1-0)) explained above in the section (resist composition). A preferred example of the component (A1-0) is a copolymer consisting only of repeating units of the structural unit (a00), the structural unit (a01), and the structural unit (a02). Based on the total (100 mol%) of all structural units constituting the component (A1-0), the proportion of structural unit (a00) within the component (A1-0) is preferably 5 to 45 mol%, more preferably 10 to 40 mol%, and even more preferably 20 to 35 mol%; the proportion of structural unit (a01) within the component (A1-0) is preferably 30 to 70 mol%, more preferably 40 to 70 mol%, and even more preferably 50 to 65 mol%; and the proportion of structural unit (a02) within the component (A1-0) is preferably 1 to 25 mol%, more preferably 2 to 20 mol%, and even more preferably 5 to 15 mol%. However, the total amount of the structural units (a00), (a01), and (a02) does not exceed 100 mol %.

[0374] The weight average molecular weight (Mw) (based on polystyrene equivalent by gel permeation chromatography (GPC)) of the copolymer according to the third aspect (component (A1-0)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. The dispersity (Mw / Mn) of the component (A1-0) is not particularly limited, but is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.0.

[0375] The copolymer related to the third aspect, that is, the component (A1-0), is a resin component that is suitable as a base component for the resist composition related to the first aspect.

[0376] (compound) A fourth aspect of the present invention is a compound represented by the following general formula (a00-M1) or general formula (a00-M2).

[0377] [ka] [In formula (a00-M1) and formula (a00-M2), R 0a and R 0b are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. 00 is a divalent linking group or a single bond. 0c is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, and an aryl group. p is an integer of 1 to 4.

[0378] In the above formula (a00-M1) and formula (a00-M2), R 0a and R 0b , L 00 represents R in the above general formula (a00). 0a and R 0b , L 00 The explanations for each are the same as those for the previous two. R 0a and R 0b are each preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability, and even more preferably a hydrogen atom; R 0a and R 0b It is particularly preferred that all of these are hydrogen atoms. L 00 is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. 00 is preferably a single bond.

[0379] In the above formula (a00-M1) and formula (a00-M2), R 0c is R in the above general formula (a00-u) 0c This is the same as the explanation for R 0cFrom the viewpoint of use in a resist composition, is preferably at least one selected from the group consisting of a halogen atom and an alkyl group, more preferably a halogen atom, and even more preferably an iodine atom from the viewpoint of the effects on sensitivity, reduction of roughness, and suppression of film loss. p is preferably 1 or 2, and more preferably 1.

[0380] Specific examples of the compound represented by general formula (a00-M1) and the compound represented by general formula (a00-M2) are shown below. In each of the following formulas, R 00a and R 00b each independently represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0381] [ka]

[0382] [ka]

[0383] [Method of manufacturing the compound] As shown in the synthesis examples below, the compound according to the fourth aspect can be prepared by, for example, combining maleic anhydride with a specific substituent (R 0c ) and an aminophenol in which an amino group is substituted at a predetermined position, in the presence of an acid catalyst.

[0384] As described above, the compound of this embodiment has a hydroxy group bonded to the meta position or the ortho position and a specific substituent (R 0c ) and can be used as a raw material monomer for the copolymer according to the third aspect. When a copolymer using the compound according to the fourth aspect is used as a base component in a resist composition, it is effective in suppressing film loss in unexposed areas of the resist film. [Example]

[0385] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the present example, the compound represented by chemical formula (1) will be referred to as "compound (1)", and the same will be used for compounds represented by other chemical formulas.

[0386] <Examples of compound synthesis> [Synthesis Example 1: Synthesis of Compound (a00-M1-1)] Maleic anhydride (10.8 g), 3-aminophenol (10.9 g), dimethylformamide (DMF) (30.0 g), and toluene (120.0 g) were added and stirred for 1 hour. After adding p-toluenesulfonic acid (1.4 g) dissolved in DMF (10.0 g), the mixture was heated to 160°C in an oil bath and stirred for 5 hours. The mixture was then cooled to room temperature, and ultrapure water (500.0 g) was added and stirred for 30 minutes. After stopping the stirring, the aqueous layer was removed and washed with a 5 wt% aqueous sodium carbonate solution (500.0 g). The aqueous layer was removed and washed with ultrapure water (500.0 g). The organic layer was concentrated under reduced pressure, and the concentrated residue was crystallized from acetonitrile / tert-butyl methyl ether to obtain 9.9 g of compound (a00-M1-1).

[0387] [ka]

[0388] The resulting compound (a00-M1-1) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=9.59(s,1H),7.86(d,2H),7.25(t,1H),6.80(d,1H),6.79(s,1H),6.77(d,1H)

[0389] [Synthesis Example 2: Synthesis of Compound (a00-M2-1)] Compound (a00-M2-1) was synthesized in the same manner as in Synthesis Example 1, except that 2-aminophenol was used instead of 3-aminophenol.

[0390] [ka]

[0391] The resulting compound (a00-M2-1) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=9.85(s,1H),7.86(d,2H),7.31(t,1H),7.16(d,1H),6.99(d,1H),6.92(t,1H)

[0392] [Synthesis Example 3: Synthesis of Compound (a00-M1-2)] Compound (a00-M1-2) was synthesized in the same manner as in Synthesis Example 1, except that 2-iodo-5-aminophenol was used instead of 3-aminophenol.

[0393] [ka]

[0394] The resulting compound (a00-M1-2) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=11.59(s,1H),7.86(d,2H),7.70(d,1H),6.98(s,1H),6.91(d,1H)

[0395] [Synthesis Example 4: Synthesis of Compound (a00-M1-3)] Compound (a00-M1-3) was synthesized in the same manner as in Synthesis Example 1 above, except that 2-fluoro-5-aminophenol was used instead of 3-aminophenol.

[0396] [ka]

[0397] The resulting compound (a00-M1-3) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=9.00(s,1H),7.86(d,2H),7.13(d,1H),7.12(s,1H),7.12(d,1H)

[0398] [Synthesis Example 5: Synthesis of Compound (a00-M2-2)] Compound (a00-M2-2) was synthesized in the same manner as in Synthesis Example 1, except that 6-amino-m-cresol was used instead of 3-aminophenol.

[0399] [ka]

[0400] The resulting compound (a00-M2-2) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=10.06(s,1H),7.86(d,2H),7.43(d,1H),6.85(d,1H),6.80(s,1H),2.28(s,3H)

[0401] [Synthesis Example 6: Synthesis of Compound (a00-M2-3)] Compound (a00-M2-3) was synthesized in the same manner as in Synthesis Example 1 above, except that 2-amino-4-iodophenol was used instead of 3-aminophenol.

[0402] [ka]

[0403] The resulting compound (a00-M2-3) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1H-NMR(DMSO-d6,400MHz)δ(ppm)=9.89(s,1H),7.86(d,2H),7.72(d,1H),7.44(s,1H),6.68(d,1H)

[0404] [Synthesis Example 7: Synthesis of Compound (a02-M-1)] 3,5-Diiodosalicylic acid (40.0 g) and tetrahydrofuran (THF) (160.0 g) were charged and dissolved with stirring. 1,1'-carbonyldiimidazole (CDI) (20.0 g) was added, and the mixture was heated to 60°C in a water bath and stirred for 1 hour. Compound (1a) (38.3 g) was added and aged for 1 hour. Ultrapure water (160.0 g) and dichloromethane (160.0 g) were then charged and stirred. After stopping the stirring, the aqueous layer was removed and washed with additional ultrapure water (160 g). The organic layer was concentrated under reduced pressure, and the concentrated residue was crystallized from acetonitrile / tert-butyl methyl ether to obtain 43.2 g of a white intermediate (Pre-P1a).

[0405] [ka]

[0406] 4-Vinylbenzoic acid (9.6 g), intermediate (Pre-P1a) (40.0 g), 4-dimethylaminopyridine (DMAP) (0.7 g), and dichloromethane (400.0 g) were stirred at 0°C. 1,3-Diisopropylcarbodiimide (DIC) (8.9 g) was added to the mixture. After stirring at room temperature for 3 hours, the mixture was concentrated under reduced pressure. The concentrated residue was crystallized from acetonitrile / tert-butyl methyl ether to obtain 31.5 g of white intermediate (Pre-P1b).

[0407] [ka]

[0408] Intermediate (Pre-P1b) (30.0 g), compound (1b) (21.3 g), dichloromethane (150.0 g), and ultrapure water (60.0 g) were stirred at room temperature and separated. The organic layer was washed five times with ultrapure water (60.0 g) and then concentrated under reduced pressure to obtain 30.5 g of compound (a02-M-1).

[0409] [ka]

[0410] The obtained compound (a02-M-1) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=8.58(d,1H),8.31(d,1H),8.13(d,2H),8. 00-7.72(m,17H),6.92-6.85(m,1H),6.07(d,1H),5.49(d,1H),4.67(t,2H)

[0411] [Synthesis Example 8: Synthesis of Compound (a02-M-2)] Compound (a02-M-2) was synthesized in the same manner as in Synthesis Example 7, except that compound (2b) was used instead of compound (1b).

[0412] [ka]

[0413] The obtained compound (a02-M-2) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=8.58(m,3H),8.31(m,3H),8.13(d,2H),8. 00-7.72(m,11H),6.92-6.85(m,1H),6.07(d,1H),5.49(d,1H),4.67(t,2H)

[0414] [Synthesis Example 9: Synthesis of compound (a02-M-3)] Compound (a02-M-3) was synthesized in the same manner as in Synthesis Example 7, except that compound (3b) was used instead of compound (1b).

[0415] [ka]

[0416] The obtained compound (a02-M-3) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=8.58(d,1H),8.31(d,1H),8.13(d,2H),8. 00-7.72(m,14H),6.92-6.85(m,1H),6.07(d,1H),5.49(d,1H),4.67(t,2H)

[0417] [Synthesis Example 10: Synthesis of Compound (a02-M-4)] Compound (a02-M-4) was synthesized in the same manner as in Synthesis Example 7, except that compound (4b) was used instead of compound (1b).

[0418] [ka]

[0419] The obtained compound (a02-M-4) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=8.58(d,1H),8.31(d,1H),8.13(d,2H),8. 00-7.72(m,13H),6.92-6.85(m,1H),6.07(d,1H),5.49(d,1H),4.67(t,2H)

[0420] [Synthesis Example 11: Synthesis of Compound (a02-M-5)] Compound (a02-M-5) was synthesized in the same manner as in Synthesis Example 7, except that compound (5b) was used instead of compound (1b).

[0421] [ka]

[0422] The obtained compound (a02-M-5) was subjected to NMR measurement, and its structure was identified from the following analytical results. 1 H-NMR(DMSO-d6,400MHz)δ(ppm)=8.58(d,1H),8.31(d,1H),8.13(d,2H),8. 00-7.72(m,11H),6.92-6.85(m,1H),6.07(d,1H),5.49(d,1H),4.67(t,2H)

[0423] <Example of copolymer synthesis> [Synthesis of copolymer (A1-0-1)] 6.0 g of compound (a00-M3-1), 10.0 g of compound (a01-M-1), 2.9 g of compound (a02-M-1), and 2.0 g of azobis(isobutyrate) dimethyl (V-601) as a polymerization initiator were dissolved in 55 g of MEK (methyl ethyl ketone), heated to 80 °C under a nitrogen atmosphere, and stirred for 6 hours. After the reaction was completed, the resulting reaction solution was precipitated in 600 g of heptane and washed. The resulting white solid was filtered and dried under reduced pressure overnight to obtain 13.0 g of the target copolymer (A1-0-1).

[0424] [ka]

[0425] [Synthesis of Copolymers (A1-0-2) to (A1-0-18)] Copolymers (A1-0-2) to (A1-0-18) were synthesized in the same manner as in the above-mentioned [Synthesis of Copolymer (A1-0-1)], except that the monomers used and the amounts used were changed.

[0426] The raw material monomers corresponding to each copolymer and the structures of the resulting copolymers (A1-0-1) to (A1-0-18) are shown below, where l, m, and n represent the compositional ratio of each structural unit.

[0427] [ka]

[0428] [ka]

[0429] [ka]

[0430] [ka]

[0431] [ka]

[0432] [ka]

[0433] [ka]

[0434] [ka]

[0435] The weight average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) of each of the resulting copolymers (A1-0-1) to (A1-0-18) were determined by GPC measurement (standard polystyrene equivalent). The copolymer composition ratios (proportions (molar ratios) of each structural unit in the structural formula) of the copolymers (A1-0-1) to (A1-0-18) were determined by carbon-13 nuclear magnetic resonance spectroscopy (600 MHz, 13 The results are shown in Table 1 along with the monomer composition.

[0436] [Table 1]

[0437] <Preparation of Resist Composition> (Examples 1 to 18, Comparative Examples 1 to 3) The components shown in Table 2 were mixed and dissolved to prepare the resist compositions of the respective examples.

[0438] [Table 2]

[0439] In Table 2, the abbreviations have the following meanings: The values ​​in brackets [ ] are the blend amounts (parts by mass; solid content equivalent). The weight average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) of the copolymer are the weight average molecular weight converted into standard polystyrene by GPC measurement. The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) is: 13 The carbon content was determined by C-NMR.

[0440] (A)-1 to (A)-18: The above-mentioned copolymers (A1-0-1) to (A1-0-18).

[0441] (A)-19: A copolymer represented by the following chemical formula (A1-1-1): Weight average molecular weight (Mw) 7900, molecular weight dispersity (Mw / Mn) 1.61, copolymer composition ratio l / m / n = 30 / 60 / 10.

[0442] (A)-20: A copolymer represented by the following chemical formula (A1-1-2), with a weight average molecular weight (Mw) of 5100, a molecular weight dispersity (Mw / Mn) of 1.50, and a copolymer composition ratio l / m=40 / 60.

[0443] [ka]

[0444] (B)-1: An acid generator comprising a compound represented by the following chemical formula (B1-1). (B)-2: An acid generator comprising a compound represented by the following chemical formula (B1-2).

[0445] [ka]

[0446] (D)-1: An acid diffusion controller comprising a compound represented by the following chemical formula (D1-1).

[0447] [ka]

[0448] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether=60 / 40 (mass ratio).

[0449] <Formation of resist pattern> Steps for forming a resist film: Each resist composition of each example was applied using a spinner onto an 8-inch silicon substrate that had been treated with hexamethyldisilazane (HMDS), and then pre-baked (PAB) on a hot plate at 110°C for 60 seconds, followed by drying to form a resist film with a thickness of 60 nm.

[0450] Step of exposing the resist film: Next, the resist film was subjected to exposure (writing) using an electron beam lithography system JEOL JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100 kV to form a 1:1 line and space pattern (hereinafter referred to as "LS pattern") with a target size of 35 nm line width and 70 nm pitch width. Thereafter, post-exposure baking (PEB) was performed at 100° C. for 60 seconds.

[0451] A process for developing the exposed resist film: Next, alkaline development was carried out at 23° C. for 60 seconds using a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, the substrate was rinsed with pure water for 15 seconds. As a result, an LS pattern with a line width of 35 nm and a pitch width of 70 nm was formed.

[0452] [Evaluation of optimal exposure (Eop)] The optimum exposure dose Eop (μC / cm) for forming a target size LS pattern by the above <Formation of resist pattern> 2 The results were recorded as "Eop (μC / cm 2 )" in Table 3.

[0453] [Evaluation of pattern roughness reduction (LWR)] The LS pattern formed in the above <Formation of Resist Pattern> was measured for 3σ, which is a measure of LWR. This is shown in Table 3 as "LWR (nm)". "3σ" indicates three times the standard deviation (σ) (unit: nm) obtained from the measurement results of measuring 400 line positions in the longitudinal direction of the line using a scanning electron microscope (accelerating voltage 800 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the less rough the line sidewalls are, meaning that an LS pattern with a more uniform width is obtained.

[0454] [Evaluation of film loss suppression] In the above <Formation of Resist Pattern>, the thickness of the resist film in the large unexposed area outside the pattern after PAB and after water rinsing were measured, and the thickness change rate of the resist film after water rinsing relative to the thickness of the resist film after PAB was calculated. This is shown in Table 3 as "Remaining Film Rate (%)". The larger the remaining film ratio, the more the unexposed portions of the resist film remain without dissolving in the developer after development, meaning that development loss (film loss) is suppressed.

[0455] [Table 3]

[0456] As can be seen from the results shown in Table 3, the resist compositions of Examples 1 to 18, to which the present invention was applied, achieved high sensitivity in resist pattern formation, and were more effective in reducing roughness and inhibiting film loss than the resist compositions of Comparative Examples 1 to 3.

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, Contains a resin component whose solubility in a developer changes under the action of acid, The resin component is A structural unit represented by the following general formula (a00): A structural unit represented by the following general formula (a01): a structural unit represented by the following general formula (a02) that generates acid upon exposure; A resist composition comprising a copolymer having the formula: 【Chemical 1】 [In formula (a00), R ０ａ and R ０ｂ are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. ００ is a divalent linking group or a single bond. Ａｒ is an aromatic group which may have a substituent, provided that the substituent which this aromatic group may have is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, an aryl group, an alkoxy group, and a hydroxy group. ０１ is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. ０１ is a divalent linking group or a single bond. Ｘ is an acid-dissociable group. ０２ is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. ０２ is a divalent linking group. － is an anionic group. ｍ＋ is an m-valent onium cation, where m is an integer of 1 or more.

2. R in the formula (a00) Ａｒ 2. The resist composition according to claim 1, wherein is an aromatic group having an iodine atom as a substituent.

3. R in the formula (a01) Ｘ is an acid-dissociable group that is bonded to the oxygen atom (—O—) in —C(═O)—O— in formula (a01) via a carbon atom, and has a carbon-carbon unsaturated bond formed between the α-position of the carbon atom and the β-position of the carbon atom.

4. M in the formula (a02) ｍ＋ 2. The resist composition according to claim 1, wherein is an m-valent onium cation having a fluorine atom.

5. Z in the formula (a02) － 2. The resist composition according to claim 1, wherein is a sulfonate ion.

6. A method for forming a resist pattern, comprising: a step of forming a resist film on a support using the resist composition according to any one of claims 1 to 5; a step of exposing the resist film; and a step of developing the exposed resist film to form a resist pattern.

7. A structural unit represented by the following general formula (a00): A structural unit represented by the following general formula (a01): a structural unit represented by the following general formula (a02) that generates acid upon exposure; A copolymer having the formula: 【Chemistry 2】 [In formula (a00), R ０ａ and R ０ｂ are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. ００ is a divalent linking group or a single bond. Ａｒ is an aromatic group which may have a substituent, provided that the substituent which this aromatic group may have is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, an aryl group, an alkoxy group, and a hydroxy group. ０１ is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. ０１ is a divalent linking group or a single bond. Ｘ is an acid-dissociable group. ０２ is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. ０２ is a divalent linking group. － is an anionic group. ｍ＋ is an m-valent onium cation, where m is an integer of 1 or more.

8. R in the formula (a00) Ａｒ The copolymer according to claim 7, wherein is an aromatic group having an iodine atom as a substituent.

9. R in the formula (a01) Ｘ is an acid-dissociable group that is bonded to the oxygen atom (—O—) in —C(═O)—O— in formula (a01) via a carbon atom and has a carbon-carbon unsaturated bond formed between the α-position of the carbon atom and the β-position of the carbon atom.

10. M in the formula (a02) ｍ＋ The copolymer according to claim 7, wherein is an m-valent onium cation having a fluorine atom.

11. Z in the formula (a02) － The copolymer of claim 7, wherein is a sulfonate ion.

12. A compound represented by the following general formula (a00-M1) or general formula (a00-M2). 【Chemistry 3】 [In formula (a00-M1) and formula (a00-M2), R ０ａ and R ０ｂ are each independently an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. ００ is a divalent linking group or a single bond. ０ｃ is at least one selected from the group consisting of a halogen atom, an alkyl group, a halogenated alkyl group, and an aryl group, and p is an integer of 1 to 4.

Images