Resist Composition and Resist Pattern Forming Method

Abstract

To provide a resist composition capable of reducing roughness of a resist pattern.SOLUTION: The resist composition contains a resin component (A1) having a constituent unit (a01) represented by the following general formula (a01-1) and a constituent unit (a02) represented by the following general formula (a02-1). The content of an acid generator component (B) is 20 pts.mass or more, and the content of a photodegradable base component (D1) is 5 pts.mass or more. In the formula (a01-1), Ra01 represents an optionally substituted aromatic hydrocarbon group. In the formula (a02-1), Wax0 represents a divalent aromatic hydrocarbon group.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] In recent years, in the production of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to the advancement of lithography technology. As a miniaturization technique, generally, the wavelength of the exposure light source is shortened (the energy is increased).

[0003] For resist materials, lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions are required. As a resist material satisfying such requirements, a chemically amplified resist composition containing a base material component whose solubility in a developer changes by the action of an acid and an acid generator component that generates an acid upon exposure has been conventionally used.

[0004] In a chemically amplified resist composition, generally, a resin having a plurality of structural units is used to improve lithography characteristics and the like. For example, Patent Document 1 describes a resist composition that employs a polymer compound having specific high acid dissociation performance and improves the reactivity with an acid.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As lithography technology makes further progress and the miniaturization of resist patterns advances further, for example, in lithography using electron beams or EUV, the formation of fine patterns with a size of several tens of nanometers is targeted. As the resist pattern size becomes smaller, the resist composition is required to further improve lithography characteristics such as higher sensitivity to the exposure light source and reduction of roughness.

[0007] As a method for further improving lithography characteristics, it is conceivable to increase the content of the acid generator. However, in the conventional resist compositions as described above, simply increasing the content of the acid generator was not sufficient to reduce roughness.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a resist composition capable of reducing the roughness of a resist pattern and a method for forming a resist pattern using the resist composition.

Means for Solving the Problems

[0009] In order to solve the above problems, the present invention employs the following configuration. That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes by the action of the acid, comprising a base material component (A) whose solubility in a developer changes by the action of the acid, an acid generator component (B) that generates an acid upon exposure, and a photo-dissociable base component (D1), wherein the base material component (A) includes a resin component (A1) having a structural unit (a01) represented by the following general formula (a01-1) and a structural unit (a02) represented by the following general formula (a02-1), the content of the acid generator component (B) is 20 parts by mass or more with respect to 100 parts by mass of the base material component (A), and the content of the photo-dissociable base component (D1) is 5 parts by mass or more with respect to 100 parts by mass of the base material component (A).

[0010]

Chemical formula

[0011]

Chemical formula

[0012] A second aspect of the present invention is a resist pattern forming method including a step of forming a resist film on a support using the resist composition according to the first aspect, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern.

Advantages of the Invention

[0013] According to the present invention, it is possible to provide a resist composition capable of reducing the roughness of a resist pattern and a resist pattern forming method using the resist composition.

Embodiments for Carrying Out the Invention

[0014] In the present specification and the claims, “aliphatic” is a relative concept with respect to aromatic, and is defined to mean a group, a compound, etc. having no aromaticity. "Alkyl group" shall include linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in an alkoxy group. "Alkylene group" shall include linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified. "Halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. "Constituent unit" means a monomer unit (monomeric unit) that constitutes a high molecular compound (resin, polymer, copolymer). When it is described as "may have a substituent", it includes both the case of substituting a hydrogen atom (-H) with a monovalent group and the case of substituting a methylene group (-CH2-) with a divalent group. "Exposure" is a concept that includes all irradiations of radiation.

[0015] "Acid-decomposable group" is a group having acid-decomposability such that at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group. Examples of the polar group include a carboxy group, a hydroxy group, an amino group, a sulfo group (-SO3H), etc. More specifically, examples of the acid-decomposable group include a group in which the polar group is protected by an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0016] "Acid-dissociable group" means both (i) a group having acid-dissociability such that the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group in which, after a part of the bonds are cleaved by the action of an acid, a decarboxylation reaction further occurs, whereby the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved. The acid-dissociable group constituting the acid-decomposable group needs to be a group with lower polarity than the polar group generated by the dissociation of the acid-dissociable group. Thus, 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 (A1) component increases. By increasing the polarity, relatively, the solubility in the developer changes. When the developer is an alkaline developer, the solubility increases, and when the developer is an organic-based developer, the solubility decreases.

[0017] The "base material component" is an organic compound having film-forming ability. The organic compounds used as the base material component are roughly classified into non-polymers and polymers. As the non-polymer, usually, those with a molecular weight of 500 or more and less than 4000 are used. Hereinafter, when referring to a "low molecular compound", it means a non-polymer with a molecular weight of 500 or more and less than 4000. As the polymer, usually, those with a molecular weight of 1000 or more are used. Hereinafter, when referring to "resin", "high molecular compound" or "polymer", it means a polymer with a molecular weight of 1000 or more. As the molecular weight of the polymer, the mass average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography) shall be used.

[0018] The "derived structural unit" means a structural unit formed by the cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. In the "acrylic acid ester", the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. The substituent (R αx ) is an atom or group other than a hydrogen atom. Also, it shall include itaconic acid diesters in which the substituent (R αx ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R αx ) is substituted with a hydroxyalkyl group or a group obtained by modifying its hydroxyl group. Note that the α-position carbon atom of the acrylic acid ester is, unless otherwise specified, the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylate in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylate.

[0019] The term "derivative" refers to a concept that includes those in which a 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, and derivatives thereof. Examples of such derivatives include those in which a hydrogen atom of the hydroxyl group of the target compound, which may have a hydrogen atom at the α-position substituted with a substituent, is substituted with an organic group; those in which a substituent other than a hydroxyl group is bonded to the target compound, which may have a hydrogen atom at the α-position substituted with a substituent, and the like. Here, the α-position refers to the first carbon atom adjacent to the functional group, unless otherwise specified. Examples of the substituent that substitutes the hydrogen atom at the α-position of hydroxystyrene include those similar to R αx as described above.

[0020] In this specification and the claims of the present patent, depending on the structure represented by the chemical formula, there may be an asymmetric carbon, and enantiomers or diastereomers may exist. In that case, those isomers are represented by one chemical formula. Those isomers may be used alone or as a mixture.

[0021] (Resist composition) The resist composition according to the first aspect of the present invention generates an acid upon exposure and changes its solubility in a developer by the action of the acid. It contains a base material component (A) (hereinafter also referred to as the "(A) component") whose solubility in a developer changes by the action of the acid, an acid generator component (B) (hereinafter also referred to as the "(B) component") that generates an acid upon exposure, and a photo-disintegrating base component (D1) (hereinafter also referred to as the "(D1) component") that decomposes upon exposure and loses acid diffusion controllability.

[0022] When a resist film is formed using the resist composition of the present embodiment and selective exposure is performed on the resist film, acid is generated in the exposed portion of the resist film, and the solubility of the component (A) in the developer changes due to the action of the acid. On the other hand, in the unexposed portion of the resist film, the solubility of the component (A) in the developer does not change. Therefore, a difference in solubility in the developer occurs between the exposed portion and the unexposed portion of the resist film.

[0023] The resist composition of the present embodiment may be a positive resist composition or a negative resist composition. Further, the resist composition of the present embodiment may be for an alkali development process using an alkali developer for the development treatment during resist pattern formation, or may be for a solvent development process using an organic developer for the development treatment. That is, the resist composition of the present embodiment is a "positive resist composition for alkali development process" that forms a positive resist pattern in the alkali development process, and a "negative resist composition for solvent development process" that forms a negative resist pattern in the solvent development process.

[0024] <(Component A)> In the resist composition of the present embodiment, the component (A) includes a resin component (A1) (hereinafter also referred to as "(A1) component") having a structural unit (a01) represented by the following general formula (a01-1) and a structural unit (a02) represented by the following general formula (a02-1). As the component (A), at least the (A1) component is used, and at least one of other high molecular compounds and low molecular compounds may be used in combination with the (A1) component.

[0025] In the resist composition of the present embodiment, the component (A) may be used alone or in combination of two or more.

[0026] ·Regarding the (A1) component The (A1) component includes a structural unit (a01) and a structural unit (a02).

[0027] <<Constituent Unit (a01)>> The constituent unit (a01) is a constituent unit represented by the following general formula (a01-1).

[0028] [Chemical Formula] [In the formula, R 01 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 01 is a divalent hydrocarbon group which may have an ether bond. n a01 is an integer of 0 to 2. Ra 01 is an aromatic hydrocarbon group which may have a substituent. Ra 02 and Ra 03 are each independently a hydrocarbon group which may have a substituent, and Ra 02 and Ra 03 may be bonded to each other to form a ring.]

[0029] In the above formula (a01-1), R 01 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. may be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is most preferable.

[0030] In the above formula (a01-1), Va 01 is a divalent hydrocarbon group which may have an ether bond. The divalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0031] Va 01 As the divalent hydrocarbon group in Va, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. More specifically, examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in the structure.

[0032] The linear aliphatic 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 most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and other alkylalkylene groups. The alkyl group in the alkylalkylene group preferably has 1 to 5 carbon atoms and is a linear alkyl group.

[0033] Examples of the aliphatic hydrocarbon group containing a ring in the above structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those of the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane, and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0034] Va 01 The aromatic hydrocarbon group as the divalent hydrocarbon group in is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. However, the carbon number does not include the carbon number in the substituent. Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group in which one of the hydrogen atoms of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom 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 (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0035] In the above formula (a01-1), n a01 is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0036] In the above formula (a01-1), Ra 01is an aromatic hydrocarbon group which may have a substituent. The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specifically, as the aromatic ring, aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom, etc. may be mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. Specifically, as the aromatic heterocyclic ring, a pyridine ring, a thiophene ring, etc. may be mentioned. Specifically, as the aromatic hydrocarbon group, a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1. Among the above, the aromatic hydrocarbon group is preferably a hydrocarbon group having one benzene ring (phenyl group).

[0037] When the above aromatic hydrocarbon group is substituted, examples of the substituent include an alkyl group, a hydroxy group, a carboxy group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), an alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), an alkyloxycarbonyl group, etc. Among them, as the substituent, an alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or a t-butyl group is more preferable.

[0038] Among them, Ra 01 is preferably a phenyl group, 4-methylphenyl group or 4-t-butylphenyl group.

[0039] In the above formula (a01-1), Ra 02 and Ra 03 are each independently a hydrocarbon group which may have a substituent, and Ra 02 and Ra 03 may be bonded to each other to form a ring. Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, or 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. Specifically, 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 preferable, and a methyl group or an ethyl group is more preferable.

[0040] The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc., and an isopropyl group is preferable.

[0041] When Ra 02 and Ra 03 are cyclic hydrocarbon groups, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, examples include cyclopentane, cyclohexane, etc. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable. As the polycycloalkane, those having 7 to 12 carbon atoms are preferable, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like can be mentioned.

[0042] Ra 02 and Ra 03 When the cyclic hydrocarbon group of Ra and Ra becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. Ra 02 and Ra 03 Specific examples of the aromatic hydrocarbon group in Ra and Ra include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0043] Ra02 and Ra 03 The cyclic hydrocarbon group in may have a substituent. Examples of this substituent include, for example, -R P1 , -R P2 , -O-R P1 , -R P2 , -CO-R P1 , -R P2 , -CO-OR P1 , -R P2 , -O-CO-R P1 , -R P2 , -OH, -R P2 , -CN or -R P2 , -COOH (hereinafter these substituents are also collectively referred to as "Ra x0 ").) and the like. Here, R P1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, R P1 and R P2 Some or all of the hydrogen atoms of the linear saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group may be substituted with fluorine atoms. The above aliphatic cyclic hydrocarbon group may have one or more of the above substituents alone, or may have one or more of a plurality of the above substituents. Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms include, for example, 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 decyl group, and the like. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group; polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl group, tetracyclo[6.2.1.13,6.02,7]dodecanyl group, adamantyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene.

[0044] Ra 02 and Ra 03 When Ra and Ra are bonded to each other to form a cyclic group (cyclic hydrocarbon group), the cyclic group may be a polycyclic group or a monocyclic group. Further, the cyclic group may be an alicyclic hydrocarbon group or a condensed polycyclic hydrocarbon group in which an aromatic ring is condensed with the alicyclic hydrocarbon group. Furthermore, a part of the carbon atoms constituting the ring structure of the cyclic aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom. Preferred examples of the substituent containing a hetero atom include -O-, -C(=O)-, -C(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O-.

[0045] As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane or a monocycloalkene is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The monocycloalkene preferably has 3 to 6 carbon atoms, and specific examples include cyclopentene and cyclohexene. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane or a polycycloalkene is preferable. As the polycycloalkane, those having 7 to 12 carbon atoms are preferable, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like can be mentioned. Further, as the polycycloalkene, those having 7 to 12 carbon atoms are preferable, and specifically, adamantene, norbornene, isobornene, tricyclodecene, tetracyclododecene and the like can be mentioned. Examples of the condensed polycyclic hydrocarbon group in which an aromatic ring is condensed to the alicyclic hydrocarbon group include groups obtained by removing one hydrogen atom from the alicyclic ring of bicyclic compounds such as tetrahydronaphthalene and indane.

[0046] R 12 and R 13 The cyclic group formed by bonding with each other may have a substituent. Examples of the substituent include the above Ra x0 and the like.

[0047] In the above formula (a01-1), Ra 02 and Ra 03 preferably bond to each other to form a ring, and Ra 02 and Ra 03 more preferably bond to each other to form a monocyclic alicyclic hydrocarbon group.

[0048] The constitutional unit (a01) is preferably a constitutional unit represented by the following general formula (a01-11).

[0049]

Chemical formula

[0050] In the above formula (a01-11), R 01 and Ra 01 are the same as R 01 and Ra 01 in the above formula (a01-1). In the above formula (a01-11), as the monocyclic alicyclic hydrocarbon group formed by Xa 01 and Ya 01 together, a group obtained by removing two hydrogen atoms from monocycloalkane is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and cyclopentane or cyclohexane is more preferable.

[0051] In the above formula (a01-11), the monocyclic alicyclic hydrocarbon group formed by Xa 01 and Ya 01 together may have a substituent, and examples of the substituent include the above Ra x0 and the like. Furthermore, in the monocyclic alicyclic hydrocarbon group, a part of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing a hetero atom, -O-, -C(=O)-, -C(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O- are preferable.

[0052] In the above formula (a01-11), among the above, the monocyclic alicyclic hydrocarbon group formed by Xa 01 and Ya 01 together preferably has no substituent.

[0053] Preferred specific examples of the structural unit (a01) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0054]

Chemical formula

[0055]

Chemical formula

[0056] Among the above, the structural unit (a01) is preferably a structural unit represented by any of the above formulas (a01-1-01) to (a01-1-10), and more preferably a structural unit represented by any of the above formulas (a01-1-01) to (a01-1-06).

[0057] The structural unit (a01) contained in the component (A1) may be one kind or two or more kinds. The proportion of the structural unit (a01) in the component (A1) is preferably 10 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 50 to 70 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). By setting the proportion of the structural unit (a01) to be equal to or higher than the lower limit value of the above preferable range, lithography characteristics such as sensitivity, resolution, and roughness improvement are improved. Further, when the proportion of the structural unit (a01) is equal to or lower than the upper limit value of the above preferable range, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0058] ≪Structural unit (a02)≫ The structural unit (a02) is a structural unit represented by the following general formula (a02-1).

[0059] [Chemical formula] [In the formula, R 02 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya x0 is a single bond or a divalent linking group. Wa x0 is a divalent aromatic hydrocarbon group.]

[0060] In the formula (a02-1), R 02 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R in the above formula (a01-1)01 The same applies.

[0061] In formula (a02-1), Ya x0 is a single bond or a divalent linking group. In the above chemical formula, Ya x0 The divalent linking group in is not particularly limited, but examples of preferred ones include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like.

[0062] Ya x0 Examples of the divalent hydrocarbon group in include the same ones as the divalent hydrocarbon group in Va in the above formula (a01-1) 01 described above.

[0063] · Divalent linking group containing a heteroatom: When Ya x0 is a divalent linking group containing a heteroatom, preferred examples of the linking group include -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2-, -S(=O)2-O-, general formula -Y 21 -O-Y 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O-Y 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 - represented groups [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 from 0 to 3.], and the like. When the divalent linking group containing a heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H thereof may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms. General formula -Y 21 -O-Y 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 - Among them, 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 same ones as those mentioned in the description of the divalent linking group in the above Ya x0 (a divalent hydrocarbon group which may have a substituent). Y 21 Preferably, Y is a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. Y 22 Preferably, Y is a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and most preferably a methyl group. In the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 -, m” is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, the formula -[Y21 -C(=O)-O] m” -Y 22 The group represented by - is the formula -Y 21 -C(=O)-O-Y 22 - is particularly preferred. Among them, the formula -(CH2) a’ -C(=O)-O-(CH2) b’ - is preferred. In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0064] Among the above, Ya x0 is preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-].

[0065] In formula (a02-1), Wa x0 is a divalent aromatic hydrocarbon group. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specifically, the aromatic ring includes aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom, and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specifically, the aromatic heterocyclic ring includes a pyridine ring, a thiophene ring, and the like.

[0066] In formula (a02-1), Wa x0Among them, a group obtained by removing two hydrogen atoms from benzene, naphthalene, anthracene or biphenyl is preferable, a group obtained by removing two hydrogen atoms from benzene or naphthalene is more preferable, and a group obtained by removing two hydrogen atoms from benzene is even more preferable.

[0067] Preferred specific examples of the structural unit (a02) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0068]

Chemical formula

[0069]

Chemical formula

[0070] Among them, the structural unit (a02) is preferably a structural unit represented by any of the above formulas (a02-1-01) to (a02-1-6), and more preferably a structural unit represented by any of the above formulas (a02-1-01), (a02-1-02), (a02-1-05).

[0071] The structural unit (a02) contained in the component (A1) may be one kind or two or more kinds. The proportion of the structural unit (a02) in the component (A1) is preferably 10 to 80 mol%, more preferably 20 to 50 mol%, and even more preferably 30 to 50 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). By setting the proportion of the structural unit (a02) to be equal to or higher than the lower limit value of the above preferable range, the sensitivity is more likely to be enhanced. On the other hand, by setting the proportion of the structural unit (a02) to be equal to or lower than the upper limit value of the above preferable range, it becomes easier to balance with other structural units.

[0072] ≪Other structural units≫ The component (A1) may contain other structural units, in addition to the aforementioned structural units (a01) and (a02), as necessary. Examples of other structural units include structural units (a1) containing an acid-decomposable group whose polarity increases under the action of acid (provided that this excludes those corresponding to the structural unit (a01) described above); structural units (a2) containing a lactone-containing cyclic group, an —SO—-containing cyclic group, or a carbonate-containing cyclic group; structural units (a3) containing a polar group-containing aliphatic hydrocarbon group; structural units (a4) containing an acid-non-dissociable aliphatic cyclic group; structural units (a10) represented by the below-described general formula (a10-1) (provided that this excludes those corresponding to the structural unit (a02) described above); and structural units (st) derived from styrene or a styrene derivative.

[0073] Regarding the structural unit (a1): The component (A1) may further include a structural unit (a1) (excluding those that fall under the category of structural unit (a01)) that contains an acid-decomposable group whose polarity increases when acted upon by acid.

[0074] Examples of the acid-dissociable group within the structural unit (a1) include those groups that have been proposed as acid-dissociable groups for base resins used in chemically amplified resists. Specific examples of acid-dissociable groups that have been proposed for use in base resins for chemically amplified resists include the "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "tertiary alkyloxycarbonyl acid-dissociable groups," which are described below.

[0075] Acetal type acid dissociable group: Among the polar groups, examples of the acid-dissociable group that protects a carboxy group or a hydroxyl group include acid-dissociable groups represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as "acetal-type acid-dissociable groups").

[0076] [ka] [In the formula, Ra' 1 , Ra' 2is a hydrogen atom or an alkyl group. Ra’ 3 is a hydrocarbon group, and Ra’ 3 is Ra’ 1 and Ra’ 2 may combine with any one of them to form a ring.]

[0077] In formula (a1-r-1), Ra’ 1 and Ra’ 2 Among them, at least one of them is preferably a hydrogen atom, and more preferably both are hydrogen atoms. Ra’ 1 or Ra’ 2 When it is an alkyl group, examples of the alkyl group include the same alkyl groups as those listed as substituents that may be bonded to the α-carbon atom in the description of the above α-substituted acrylic acid ester, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, a linear or branched alkyl group is preferably mentioned. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. are mentioned, a methyl group or an ethyl group is more preferred, and a methyl group is particularly preferred.

[0078] In formula (a1-r-1), examples of the hydrocarbon group of Ra’ 3 include a linear or branched alkyl group or 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. Specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. are mentioned. 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.

[0079] The branched-chain alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc., and an isopropyl group is preferred.

[0080] Ra’ 3 When Ra’ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, cyclopentane, cyclohexane, etc. are exemplified. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from polycycloalkane is preferred. The polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. are exemplified.

[0081] Ra’ 3 When the cyclic hydrocarbon group of Ra’ is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom, etc. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. Specific examples of the aromatic heterocyclic ring include a pyridine ring, a thiophene ring, etc. Ra’ 3Specific examples of the aromatic hydrocarbon group in [description] include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (such as arylalkyl groups like benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0082] Ra’ 3 The cyclic hydrocarbon group in [description] may have a substituent. Examples of this substituent include the above Ra x0 and the like.

[0083] Ra’ 3 When Ra’ 1 binds to either Ra’ 2 to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group, a tetrahydrofuranyl group, and the like.

[0084] Tertiary alkyl ester type acid dissociable group: Among the above polar groups, examples of the acid dissociable group that protects the carboxy group include an acid dissociable group represented by the following general formula (a1-r-2). Among the acid dissociable groups represented by the following formula (a1-r-2), those composed of an alkyl group may be hereinafter referred to as "tertiary alkyl ester type acid dissociable group" for convenience.

[0085]

Chemical formula

[0086] Examples of the hydrocarbon group of Ra’ 4 include a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group. Examples of the linear or branched alkyl group and cyclic hydrocarbon group (aliphatic hydrocarbon group which is a monocyclic group, aliphatic hydrocarbon group which is a polycyclic group, aromatic hydrocarbon group) in Ra’ 4 are the same as those of the above Ra’ 3 . The linear or cyclic alkenyl group in Ra’ 4 is preferably an alkenyl group having 2 to 10 carbon atoms. Examples of the hydrocarbon group of Ra’ 5 and Ra’ 6 are the same as those of the above Ra’ 3 .

[0087] When Ra’ 5 and Ra’ 6 are bonded to each other to form a ring, groups represented by the following general formula (a1-r2-1), groups represented by the following general formula (a1-r2-2), and groups represented by the following general formula (a1-r2-3) are preferably exemplified. On the other hand, when Ra’ 4 to Ra’ 6 are not bonded to each other and are independent hydrocarbon groups, groups represented by the following general formula (a1-r2-4) are preferably exemplified.

[0088]

Chemical formula

[0089] 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.

[0090] Ra’ 10 As the linear alkyl group in, it has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra’ 10 As the branched alkyl group in, those similar to the above Ra’ 3 can be mentioned.

[0091] Ra’ 10The 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. Examples of heteroatoms include oxygen, sulfur, and nitrogen atoms. Examples of heteroatom-containing groups 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-.

[0092] 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, a monocyclic alicyclic hydrocarbon group is preferred, and specifically, a cyclopentyl group or a cyclohexyl group is more preferred, with a cyclopentyl group being even more preferred.

[0093] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the formula (a1-r-1). 3 Examples of such groups include groups in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) shown above. 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 above formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Ra 101 ~Ra103 Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group; polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl group, tetracyclo[6.2.1.13,6.02,7]dodecanyl group, adamantyl group and the like. Ra 101 ~Ra 103 Among them, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among them, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

[0094] The above Ra 101 ~Ra 103 Examples of the substituent of the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by include the same groups as the above Ra x0 and the like.

[0095] Ra 101 ~Ra 103 Examples of the group containing a carbon-carbon double bond formed by two or more of Ra

[0096] 3 When Xaa and Yaa form an aliphatic cyclic group in the formula (a1-r2-3), the group exemplified as the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of Ra' in the formula (a1-r-1) is preferable. 104Examples of the aromatic hydrocarbon group include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra 104 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.

[0097] Examples of the substituent that Ra 104 in formula (a1-r2-3) may have include, for example, a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), an alkyloxycarbonyl group and the like.

[0098] In formula (a1-r2-4), Ra’ 12 and Ra’ 13 are each independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in Ra’ 12 and Ra’ 13 are the same as those of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in the above Ra 101 ~Ra 103 . Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra’ 12 and Ra’ 13 are preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, still more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. When the linear saturated hydrocarbon group represented by the above Ra’ 12 and Ra’ 13 is substituted, examples of the substituent include the same groups as those of the above Ra x0 .

[0099] In formula (a1-r2-4), Ra’ 14 is a hydrocarbon group which may have a substituent. Ra’ 14 Examples of the hydrocarbon group in Ra’ include a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0100] Ra’ 14 The linear alkyl group in Ra’ preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, 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.

[0101] Ra’ 14 The branched alkyl group in Ra’ preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc., and an isopropyl group is preferred.

[0102] Ra’ 14 When Ra’ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may also be a polycyclic group or a monocyclic group. As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, examples include cyclopentane, cyclohexane, etc. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from polycycloalkane is preferred. The polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, examples include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0103] Ra’ 14Examples of the aromatic hydrocarbon group in [X] include Ra 104 The same groups as the aromatic hydrocarbon group in [X] can be mentioned. Among them, Ra’ 14 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene, and most preferably a group obtained by removing one or more hydrogen atoms from naphthalene. Ra’ 14 Examples of the substituent that Ra’ 104 may have include the same groups as the substituent that Ra

[0104] In the formula (a1-r2-4), when Ra’ 14 is a naphthyl group, the position bonded to the tertiary carbon atom in the formula (a1-r2-4) may be either the 1-position or the 2-position of the naphthyl group. In the formula (a1-r2-4), when Ra’ 14 is an anthryl group, the position bonded to the tertiary carbon atom in the formula (a1-r2-4) may be any of the 1-position, 2-position or 9-position of the anthryl group.

[0105] Specific examples of the group represented by the formula (a1-r2-1) are given below.

[0106] [Chemical formula]

[0107] [Chemical formula]

[0108] [Chemical formula]

[0109] Specific examples of the group represented by the formula (a1-r2-2) are given below.

[0110] [Chemical formula]

[0111] [Chemical formula]

[0112] [Chemical formula]

[0113] Specific examples of the group represented by the formula (a1-r2-3) are given below.

[0114] [Chemical formula]

[0115] Specific examples of the group represented by the formula (a1-r2-4) are given below.

[0116] [Chemical formula]

[0117] Tertiary alkyloxycarbonyl acid dissociable group: Among the above polar groups, examples of the acid dissociable group for protecting the hydroxyl group include the acid dissociable group represented by the following general formula (a1-r-3) (hereinafter sometimes referred to as "tertiary alkyloxycarbonyl acid dissociable group" for convenience).

[0118] [Chemical formula] [In the formula, Ra’ 7 ~Ra’ 9 are each independently an alkyl group.]

[0119] In formula (a1-r-3), Ra’ 7 ~Ra’ 9 is each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms. Also, the total number of carbon atoms of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0120] Examples of the structural unit (a1) include a structural unit derived from an acrylate ester in which a hydrogen atom bonded to an α-position carbon atom may be substituted with a substituent, a structural unit derived from acrylamide, a structural unit in which at least a part of the hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected with a substituent containing the acid-decomposable group, a structural unit in which at least a part of the hydrogen atoms in -C(=O)-OH of a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative is protected with a substituent containing the acid-decomposable group, and the like.

[0121] Among the above, as the structural unit (a1), a structural unit derived from an acrylate ester in which a hydrogen atom bonded to an α-position carbon atom may be substituted with a substituent is preferable. Preferable specific examples of such a structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2). However, those corresponding to the above-described structural unit (a0) are excluded.

[0122]

Chemical formula

[0123] In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. can be mentioned. The alkyl halide group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable. From the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is most preferable.

[0124] 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0125] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure.

[0126] The linear aliphatic 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 most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-; and other alkylalkylene groups. The alkyl group in the alkylalkylene group preferably has 1 to 5 carbon atoms and is a linear alkyl group.

[0127] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those of the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, cyclopentane, cyclohexane, etc. may be mentioned. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. may be mentioned.

[0128] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. However, the carbon number does not include the carbon number in the substituent. Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom 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, and a 2-naphthylethyl group). The carbon number of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0129] In the formula (a1-1), Ra 1 is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0130] In the formula (a1-2), Wa 1 n in a2 The +1-valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a group combining a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in the structure. The above n a2 The +1-valent is preferably divalent to tetravalent, more preferably divalent or trivalent.

[0131] In the formula (a1-2), Ra 2 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0132] Specific examples of the structural unit represented by the formula (a1-1) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0133]

Chemical formula

[0134]

Chemical formula

[0135]

Chemical formula

[0136]

Chemical formula

[0137] [Chemical formula]

[0138] [Chemical formula]

[0139] [Chemical formula]

[0140] (A1) component may have one or more than two kinds of structural units (a1). As the structural unit (a1), the structural unit represented by the formula (a1-1) is more preferable because the characteristics (sensitivity, shape, etc.) in lithography using an electron beam or EUV can be more easily enhanced. Among these, as the structural unit (a1), those containing the structural unit represented by the following general formula (a1-1-1) are particularly preferable. However, those corresponding to the above-described structural unit (a0) are excluded.

[0141] [Chemical formula] [In the formula, Ra 1 ” is an acid dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4).]

[0142] In the formula (a1-1-1), R, Va 1 and n a1 are the same as R, Va 1 and n a1 in the formula (a1-1). The description of the acid dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4) is as described above. Among them, since it is suitable for enhancing reactivity in the case of EB or EUV, it is preferable to select an acid dissociable group which is a cyclic group.

[0143] In the formula (a1-1-1), Ra 1 ” is preferably an acid dissociable group represented by the general formula (a1-r2-1) among the above.

[0144] The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 65 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). By setting the proportion of the structural unit (a1) to be equal to or higher than the lower limit value of the above preferable range, lithography characteristics such as sensitivity, resolution, and roughness improvement are improved. On the other hand, when it is equal to or lower than the upper limit value of the above preferable range, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0145] Regarding the structural unit (a2): The component (A1) may further have a structural unit (a2) containing a lactone-containing cyclic group, a -SO2-containing cyclic group or a carbonate-containing cyclic group (however, excluding those corresponding to the structural unit (a1)). The lactone-containing cyclic group, -SO2-containing cyclic group or carbonate-containing cyclic group of the structural unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when the component (A1) is used for forming a resist film. Further, by having the structural unit (a2), lithography characteristics and the like become good due to effects such as appropriately adjusting the acid diffusion length, enhancing the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0146] The "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. Counting the lactone ring as the first ring, in the case of only the lactone ring, it is a monocyclic group, and when it further has other ring structures, regardless of the structure, it is called a polycyclic group. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. The lactone-containing cyclic group in the constitutional unit (a2) can be arbitrarily used without particular limitation. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be mentioned.

[0147] [Chemical formula] [In the formula, Ra’ 21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group or a cyano group; R” is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2-containing cyclic group; A” is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom or a sulfur atom, n’ is an integer of 0 to 2, and m’ is 0 or 1.]

[0148] In the general formulas (a2-r-1) to (a2-r-7), Ra’ 21 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group, etc. can be mentioned. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. Ra’ 21 The alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the above Ra’ 21Examples of the group in which an alkyl group mentioned as the alkyl group in [0000000] is linked to an oxygen atom (-O-) include such a group. Ra’ 21 Examples of the halogen atom in [0000000] include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferred. Ra’ 21 Examples of the alkyl halide group in [0000000] include the above Ra’ 21 Examples of the group in which some or all of the hydrogen atoms of the alkyl group in [0000000] are substituted with the above halogen atoms include such a group. As the alkyl halide group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0149] Ra’ 21 In -COOR” and -OC(=O)R” in [0000000], R” is each a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2-containing cyclic group. Examples of the alkyl group in R” may be linear, branched, or cyclic, and the number of carbon atoms is preferably 1 to 15. When R” is a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 5, and particularly preferably a methyl group or an ethyl group. When R” is a cyclic alkyl group, the number of carbon atoms is preferably 3 to 15, more preferably 4 to 12, and most preferably 5 to 10. Specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane can be exemplified. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane can be exemplified. Examples of the lactone-containing cyclic group in R” include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7) respectively. Examples of the carbonate-containing cyclic group in R” are the same as the carbonate-containing cyclic groups described below. Specifically, examples include the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) respectively. Examples of the -SO2-containing cyclic group in R” are the same as the -SO2-containing cyclic groups described below. Specifically, examples include the groups represented by the general formulas (a5-r-1) to (a5-r-4) respectively. Ra’ 21 The hydroxyalkyl group in preferably has 1 to 6 carbon atoms. Specifically, examples include groups in which at least one hydrogen atom of the alkyl group in the aforementioned Ra’ 21 is substituted with a hydroxyl group.

[0150] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A” is preferably a linear or branched alkylene group, and examples include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples include groups in which -O- or -S- is interposed at the terminal or between carbon atoms of the alkylene group, and examples include O-CH2-, -CH2-O-CH2-, -S-CH2-, -CH2-S-CH2-, etc. 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.

[0151] Specific examples of the groups represented by the general formulas (a2-r-1) to (a2-r-7) respectively are given below.

[0152]

Chemical formula

[0153]

Chemical formula

[0154] The "-SO2-containing cyclic group" refers to a cyclic group containing a ring having -SO2- in its ring skeleton. Specifically, it is a cyclic group in which the sulfur atom (S) in -SO2- forms part of the ring skeleton of the cyclic group. The ring containing -SO2- in its ring skeleton is counted as the first ring. In the case of only this ring, it is a monocyclic group, and when it has another ring structure, regardless of its structure, it is called a polycyclic group. The -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2-containing cyclic group is preferably, in particular, a cyclic group containing a ring having -O-SO2- in its ring skeleton, that is, a cyclic group containing a sultone ring in which -O-S- in -O-SO2- forms part of the ring skeleton. More specifically, examples of the -SO2-containing cyclic group include groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[0155]

Chemical formula

[0156] In the general formulas (a5-r-1) to (a5-r-2), A” is the same as A” in the general formulas (a2-r-2), (a2-r-3), (a2-r-5). Ra’ 51 Examples of the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR”, -OC(=O)R”, and hydroxyalkyl group in 21Those similar to those mentioned in the description thereof can be cited. Specific examples of the groups represented by the following general formulas (a5-r-1) to (a5-r-4) are given below. In the formula, "Ac" represents an acetyl group.

[0157]

Chemical formula

[0158]

Chemical formula

[0159]

Chemical formula

[0160] The "carbonate-containing cyclic group" refers to a cyclic group containing a ring (carbonate ring) containing -O-C(=O)-O- in its ring skeleton. Counting the carbonate ring as the first ring, in the case of only the carbonate ring, it is a monocyclic group, and when it has another ring structure, regardless of its structure, it is called a polycyclic group. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. As the carbonate ring-containing cyclic group, any group can be used without particular limitation. Specifically, the groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) are given.

[0161]

Chemical formula

[0162] In the general formulas (ax3-r-2) to (ax3-r-3), A” is the same as A” in the general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Ra’ 31 Examples of the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR”, -OC(=O)R”, and hydroxyalkyl group in are the same as those exemplified in the description of Ra’ in the general formulas (a2-r-1) to (a2-r-7). 21 The same ones as those mentioned in the description can be mentioned. Specific examples of the groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) are given below.

[0163]

Chemical formula

[0164] As the constitutional unit (a2), a constitutional unit derived from an acrylate ester in which a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent is preferable. Such a constitutional unit (a2) is preferably a constitutional unit represented by the following general formula (a2-1).

[0165]

Chemical formula

[0166] In the formula (a2-1), R is the same as described above. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is particularly preferable.

[0167] In the formula (a2-1), Ya 21 The divalent linking group in is not particularly limited, but examples thereof preferably include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.

[0168] ·Divalent hydrocarbon group which may have a substituent: When Ya 21 is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0169] ··Ya 21 The aliphatic hydrocarbon group in The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0170] ···Linear or branched aliphatic hydrocarbon group The linear aliphatic 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 most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and other alkylalkylene groups. The alkyl group in the alkylalkylene group preferably has 1 to 5 carbon atoms and is a linear alkyl group.

[0171] The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a carbonyl group, and the like.

[0172] ···an aliphatic hydrocarbon group containing a ring in the structure Examples of the aliphatic hydrocarbon group containing a ring in the 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 hetero atom 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, a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane, and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0173] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and the like. The alkyl group as the substituent preferably has 1 to 5 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent preferably has 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. The halogen atom as the substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. Preferred examples of the substituent containing a hetero atom include -O-, -C(=O)-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0174] ··Ya 21 the aromatic hydrocarbon group in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The carbon number of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0175] The hydrogen atoms of the aromatic hydrocarbon group may be substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, etc. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0176] ·Divalent linking group containing a heteroatom: Ya 21When it is a divalent linking group containing a heteroatom, preferred examples of the linking group include -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group.), -S-, -S(=O)2-, -S(=O)2-O-, general formula -Y 21 -O-Y 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 -represented groups [wherein Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m” is an integer of 0 to 3.], etc. can be mentioned. When the divalent linking group containing the heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)-, the H thereof may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms. General formula -Y 21 -O-Y 22 -,-Y 21 -O-,-Y 21 -C(=O)-O-,-C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 -among them, Y 21 and Y 22is each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same groups as those (divalent hydrocarbon groups which may have a substituent) exemplified as the divalent linking group in Ya 21 above. Y 21 is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. 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. In the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 -, m” is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, as the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 -, the group represented by the formula -Y 21 -C(=O)-O-Y 22 - is particularly preferred. Among them, the group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’ - is preferred. In the formula, a’ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b’ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0177] Among the above, Ya 21 is preferably a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0178] In the formula (a2-1), Ra 21 is a lactone-containing cyclic group, a -SO2-containing cyclic group, or a carbonate-containing cyclic group. As the lactone-containing cyclic group, -SO2-containing cyclic group, and carbonate-containing cyclic group in Ra 21 the groups represented by the general formulas (a2-r-1) to (a2-r-7), the groups represented by the general formulas (a5-r-1) to (a5-r-4), and the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) are preferably exemplified, respectively. Among them, a lactone-containing cyclic group or a -SO2-containing cyclic group is preferable, and the groups represented by the general formulas (a2-r-1), (a2-r-2), (a2-r-6), or (a5-r-1) are more preferable. Specifically, any of the groups represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1), (r-sl-1-1), and (r-sl-1-18) is more preferable.

[0179] The structural unit (a2) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has the structural unit (a2), the proportion of the structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 60 mol%, still more preferably 15 to 55 mol%, and particularly preferably 15 to 50 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). When the proportion of the structural unit (a2) is at least the preferable lower limit value, the effect of containing the structural unit (a2) can be sufficiently obtained by the above-described effect. When it is at most the upper limit value, the balance with other structural units can be achieved, and various lithography characteristics become good.

[0180] Regarding the structural unit (a3): The component (A1) may further have a structural unit (a3) containing an aliphatic hydrocarbon group having a polar group (excluding those corresponding to the structural unit (a1) or the structural unit (a2)). By the component (A1) having the structural unit (a3), the hydrophilicity of the component (A) is enhanced, contributing to the improvement of the resolution. Also, the acid diffusion length can be appropriately adjusted.

[0181] Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of the hydrogen atoms of an alkyl group is substituted with a fluorine atom, and a hydroxyl group is particularly preferable. Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and for example, in a resin for a resist composition for an ArF excimer laser, it can be appropriately selected and used from among those proposed in many cases.

[0182] When the cyclic group is a monocyclic group, the number of carbon atoms is more preferably 3 to 10. Among them, a structural unit derived from an acrylate ester containing an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which a part of the hydrogen atoms of an alkyl group is substituted with a fluorine atom is more preferable. Examples of the monocyclic group include a group obtained by removing two or more hydrogen atoms from a monocycloalkane. Specifically, groups obtained by removing two or more hydrogen atoms from monocycloalkanes such as cyclopentane, cyclohexane, and cyclooctane can be mentioned. Among these monocyclic groups, groups obtained by removing two or more hydrogen atoms from cyclopentane and groups obtained by removing two or more hydrogen atoms from cyclohexane are industrially preferable.

[0183] When the cyclic group is a polycyclic group, the number of carbon atoms in the polycyclic group is more preferably 7 to 30. Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of the hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include groups obtained by removing two or more hydrogen atoms from bicycloalkane, tricycloalkane, tetracycloalkane, etc. Specifically, groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane can be mentioned. Among these polycyclic groups, groups obtained by removing two or more hydrogen atoms from adamantane, groups obtained by removing two or more hydrogen atoms from norbornane, and groups obtained by removing two or more hydrogen atoms from tetracyclododecane are industrially preferable.

[0184] As the structural unit (a3), any one can be used without particular limitation as long as it contains a polar group-containing aliphatic hydrocarbon group. As the structural unit (a3), 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 containing a polar group-containing aliphatic hydrocarbon group is preferable. When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, a structural unit derived from a hydroxyethyl ester of acrylic acid is preferable as the structural unit (a3). Further, as the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-3) are mentioned as preferable ones; when it is a monocyclic group, the structural unit represented by the formula (a3-4) is mentioned as a preferable one.

[0185]

Chemical formula

[0186] In formula (a3-1), j is preferably 1 or 2, more preferably 1. When j is 2, it is preferred that the hydroxyl group is bonded to the 3-position and 5-position of the adamantyl group. When j is 1, it is preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group. j is preferably 1, and it is particularly preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0187] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5-position or 6-position of the norbornyl group.

[0188] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. Preferably, a 2-norbornyl group or 3-norbornyl group is bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5- or 6-position of the norbornyl group.

[0189] In formula (a3-4), t' is preferably 1 or 2. l is preferably 0 or 1. s is preferably 1. The fluorinated alkyl alcohol is preferably bonded to the 3- or 5-position of the cyclohexyl group.

[0190] The structural unit (a3) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has the structural unit (a3), the proportion of the structural unit (a3) is preferably 1 to 30 mol%, more preferably 2 to 25 mol%, still more preferably 5 to 20 mol% based on the total (100 mol%) of all the structural units constituting the component (A1). By setting the proportion of the structural unit (a3) to be equal to or higher than the preferable lower limit value, the effect of including the structural unit (a3) can be sufficiently obtained due to the above-described effect. If it is equal to or lower than the preferable upper limit value, a balance with other structural units can be achieved, and various lithography characteristics become favorable.

[0191] Regarding the structural unit (a4): The component (A1) may further have a structural unit (a4) containing an acid non-dissociable aliphatic cyclic group. When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Also, the hydrophobicity of the component (A) increases. The increase in hydrophobicity contributes to the improvement of resolution, resist pattern shape, etc., particularly in the case of a solvent development process. The "acid non-dissociable cyclic group" in the structural unit (a4) is a cyclic group that remains in the structural unit without dissociation even when an acid acts thereon when an acid is generated in the resist composition by exposure (for example, when an acid is generated from a structural unit that generates an acid upon exposure or from the component (B)).

[0192] As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing an acid non-dissociable aliphatic cyclic group is preferable. Many such cyclic groups that are conventionally known for use in resin components of resist compositions for ArF excimer lasers, KrF excimer lasers (preferably for ArF excimer lasers), etc. can be used. From the viewpoint of easy availability in industry, etc., it is particularly preferably at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent. Specific examples of the structural unit (a4) include structural units represented by the following general formulas (a4-1) to (a4-7).

[0193] [Chemical formula] [In the formula, R α is the same as described above.]

[0194] The constitutional unit (a4) contained in the component (A1) may be one type or two or more types. When the component (A1) has the constitutional unit (a4), the proportion of the constitutional unit (a4) is preferably 1 to 40 mol%, more preferably 5 to 20 mol%, based on the total (100 mol%) of all the constitutional units constituting the component (A1). By setting the proportion of the constitutional unit (a4) to be not less than the preferable lower limit value, the effect of including the constitutional unit (a4) can be sufficiently obtained. On the other hand, by setting it to be not more than the preferable upper limit value, it becomes easier to balance with other constitutional units.

[0195] Regarding the constitutional unit (a10): The constitutional unit (a10) is a constitutional unit represented by the following general formula (a10-1), excluding those corresponding to the constitutional unit (a02).

[0196] [Chemical formula] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya x1 is a single bond or a divalent linking group. Wa x1 is an aromatic hydrocarbon group which may have a substituent. n ax1 is an integer of 1 or more. However, when n ax1 is 1, Wa x1 is an aromatic hydrocarbon group having a substituent.]

[0197] In the above formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. may be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms in R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of easy availability in industry, 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 methyl group is particularly preferable.

[0198] In the above 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 a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, etc. are mentioned as preferable ones, and Ya in the above formula (a02-1) x0 The same ones as may be mentioned.

[0199] Among the above, Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-] is more preferable.

[0200] In the above formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in is an aromatic ring which may have a substituent, from (n ax1Examples of the group excluding (+1) hydrogen atoms include groups obtained by removing (+1) hydrogen atoms from aromatic compounds containing an aromatic ring which may have two or more substituents (such as biphenyl and fluorene). The aromatic ring herein 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 number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. Also, Wa x1 Examples of the aromatic hydrocarbon group in include groups obtained by removing (n ax1 +1) hydrogen atoms from aromatic compounds containing an aromatic ring which may have two or more substituents (such as biphenyl and fluorene). Among the above, Wa x1 is preferably a group obtained by removing (n ax1 +1) hydrogen atoms from benzene, naphthalene, anthracene or biphenyl, more preferably a group obtained by removing (n ax1 +1) hydrogen atoms from benzene or naphthalene, and still more preferably a group obtained by removing (n ax1 +1) hydrogen atoms from benzene.

[0201] 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, a halogenated alkyl group, etc. Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent are the same as those listed as the substituent of the cyclic aliphatic hydrocarbon group in Ya x1 The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, still more preferably an ethyl group or a methyl group, and particularly preferably a methyl group. Wa x1The aromatic hydrocarbon group in [it] preferably has no substituent.

[0202] In the above formula (a10-1), n ax1 is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, still more preferably 1, 2 or 3, and particularly preferably 1 or 2. However, when n ax1 is 1, Wa x1 is an aromatic hydrocarbon group having a substituent.

[0203] Specific examples of the structural unit (a10) represented by the above formula (a10-1) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0204]

Chemical formula

[0205]

Chemical formula

[0206] The structural unit (a10) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has the structural unit (a10), the proportion of the structural unit (a10) in the component (A1) is usually 5 to 50 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). However, from the viewpoint of more easily obtaining the effects of the present invention, the resist composition of the present embodiment preferably does not contain the structural unit (a10).

[0207] Regarding the structural unit (st): The structural unit (st) is a structural unit derived from styrene or a styrene derivative. The "structural unit derived from styrene" means a structural unit formed by cleavage of the ethylenic double bond of styrene. The "structural unit derived from a styrene derivative" means a structural unit formed by cleavage of the ethylenic double bond of a styrene derivative (excluding those corresponding to the structural unit (a10)).

[0208] The "styrene derivative" means a compound in which at least some of the hydrogen atoms of styrene are substituted with substituents. Examples of styrene derivatives include those in which the hydrogen atom at the α-position of styrene is substituted with a substituent, those in which one or more hydrogen atoms of the benzene ring of styrene are substituted with substituents, and those in which the hydrogen atom at the α-position of styrene and one or more hydrogen atoms of the benzene ring are substituted with substituents.

[0209] Examples of the substituent that substitutes the hydrogen atom at the α-position of styrene include an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms. As the alkyl group having 1 to 5 carbon atoms, a linear or branched alkyl group having 1 to 5 carbon atoms is preferable, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. can be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. As the substituent that substitutes the hydrogen atom at the α-position of styrene, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, an alkyl group having 1 to 3 carbon atoms or a fluorinated alkyl group having 1 to 3 carbon atoms is more preferable, and from the viewpoint of easy availability in industry, a methyl group is even more preferable.

[0210] Examples of the substituent that substitutes the hydrogen atom of the benzene ring of styrene include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, etc. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group is more preferable, and a methoxy group or an ethoxy group is even more preferable. As the halogen atom as the substituent, a fluorine atom is preferable. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. As the substituent that substitutes the hydrogen atom of the benzene ring of styrene, an alkyl group having 1 to 5 carbon atoms is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is even more preferable.

[0211] As the structural unit (st), a structural unit derived from styrene or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms is preferable, a structural unit derived from styrene or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with a methyl group is more preferable, and a structural unit derived from styrene is even more preferable.

[0212] The structural unit (st) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has a structural unit (st), the proportion of the structural unit (st) is preferably 1 to 30 mol%, more preferably 3 to 20 mol%, based on the total (100 mol%) of all the structural units constituting the component (A1).

[0213] The component (A1) contained in the resist composition may be used alone or in combination of two or more. In the resist composition of this embodiment, the component (A1) is a polymer compound having a repeating structure of a constitutional unit (a01) and a constitutional unit (a02). Preferred component (A1) includes a polymer compound composed of a repeating structure of a constitutional unit (a01) and a constitutional unit (a02); a polymer compound composed of a repeating structure of a constitutional unit (a01), a constitutional unit (a02), and a constitutional unit (a1); a polymer compound composed of a repeating structure of a constitutional unit (a01), a constitutional unit (a02), and a constitutional unit (a2); a polymer compound composed of a repeating structure of a constitutional unit (a01), a constitutional unit (a02), and a constitutional unit (a3). More preferably, it is a polymer compound composed of a repeating structure of a constitutional unit (a01) and a constitutional unit (a02).

[0214] Such component (A1) can be produced by dissolving monomers that induce each constitutional unit in a polymerization solvent, adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (such as V-601, etc.) thereto, and performing polymerization. Alternatively, such component (A1) can be produced by dissolving a monomer that induces a constitutional unit (a01) and a monomer that induces a constitutional unit (a02) in a polymerization solvent, adding the above radical polymerization initiator thereto, performing polymerization, and then performing a deprotection reaction. In addition, during polymerization, for example, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH can be used in combination to introduce a -C(CF3)2-OH group at the terminal. In this way, a copolymer into which a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is introduced is effective for reducing development defects and LER (Line Edge Roughness: uneven irregularities on the line sidewall).

[0215] The weight average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 2000 to 30000, and even more preferably 3000 to 20000. When the Mw of the component (A1) is equal to or less than the preferable upper limit value of this range, it has sufficient solubility in a resist solvent for use as a resist. When it is equal to or greater than the preferable lower limit value of this range, the dry etching resistance and the cross-sectional shape of the resist pattern are good. The dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Here, Mn represents the number average molecular weight.

[0216] ·Regarding the component (A2) The resist composition of the present embodiment may further contain, as the component (A), a base material component (hereinafter referred to as the "component (A2)") that does not correspond to the component (A1) and whose solubility in a developer changes by the action of an acid. The component (A2) is not particularly limited, and may be arbitrarily selected from a number of conventionally known base material components for chemically amplified resist compositions and used. As the component (A2), one kind of a high molecular compound or a low molecular compound may be used alone, or two or more kinds may be used in combination.

[0217] The ratio of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, further preferably 75% by mass or more, and may be 100% by mass, based on the total mass of the component (A). When the ratio is 25% by mass or more, a resist pattern excellent in various lithography characteristics such as high sensitivity, resolution, and roughness improvement is likely to be formed.

[0218] In the resist composition of the present embodiment, the content of the component (A) may be adjusted according to the resist film thickness to be formed and the like.

[0219] <Acid generator component (B)> In addition to the component (A), the resist composition of the present embodiment further contains an acid generator component (B) (hereinafter referred to as the "component (B)") that generates an acid upon exposure. (B) The component is not particularly limited, and those 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 sulfonyldiazomethanes, poly(bissulfonyl)diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, disulfone-based acid generators, and many others.

[0220] Examples of onium salt-based acid generators include, for example, a compound represented by the following general formula (b-1) (hereinafter also referred to as the “(b-1) component”), a compound represented by general formula (b-2) (hereinafter also referred to as the “(b-2) component”), or a compound represented by general formula (b-3) (hereinafter also referred to as the “(b-3) component”).

[0221] [Chemical formula] [In the formula, R 101 and R 104 ~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. R 104 and R 105 may be bonded to each other to form a ring structure. R 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 ~V 103 are each independently a single bond, an alkylene group or a fluorinated alkylene group. L 101 ~L 102 are each independently a single bond or an oxygen atom. L 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. ]

[0222] {Anion part} ·Anions in component (b-1) In formula (b-1), R 101 is a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent.

[0223] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Also, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0224] R 101 The aromatic hydrocarbon group in is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R 101 Specific examples of the aromatic ring of the aromatic hydrocarbon group in include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which a part of the carbon atoms constituting these aromatic rings is substituted with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. R 101Specific examples of the aromatic hydrocarbon group in [description] include a group obtained by removing one hydrogen atom 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 is substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0225] R 101 The cyclic aliphatic hydrocarbon group in [description] includes an aliphatic hydrocarbon group containing a ring in its structure. Examples of the aliphatic hydrocarbon group containing a ring in this structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 20, and more preferably 3 to 12. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane, etc. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, as the polycycloalkane, polycycloalkanes having a crosslinked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane; and polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferable.

[0226] Among them, R 101The cyclic aliphatic hydrocarbon group in [ID] is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or polycycloalkane, more preferably a group obtained by removing one hydrogen atom from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0227] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. may be mentioned. 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, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, etc. may be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0228] Also, R 101The cyclic hydrocarbon group in the formula may contain a heteroatom such as a heterocyclic ring. Specifically, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16) can be mentioned. In the formulas, * represents a bond that binds to Y in the formula (b-1). 101 represents a bond that binds to

[0229] [Chemical formula]

[0230] R 101 Examples of the substituent in the cyclic group of R include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, -C(=O)OR XYZ , -OC(=O)R XYZ (R XYZ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2-containing cyclic group), etc. As the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are most preferable. As the halogen atom as a substituent, a fluorine atom is preferable. As the halogenated alkyl group as a substituent, a group in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group, are substituted with the halogen atom can be mentioned. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) constituting the cyclic hydrocarbon group.

[0231] -C(=O)OR as a substituent XYZ and -OC(=O)R XYZ As the lactone-containing cyclic group, -SO2-containing cyclic group, and carbonate-containing cyclic group in, the groups represented by the general formulas (a2-r-1) to (a2-r-7), the groups represented by the general formulas (a5-r-1) to (a5-r-4), and the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) are preferably exemplified, respectively.

[0232] R 101 The cyclic hydrocarbon group in may be a condensed cyclic group containing a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed. Examples of the condensed ring include those in which one or more aromatic rings are condensed to a polycycloalkane having a bridged ring system polycyclic skeleton. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. As the condensed cyclic group, a group containing a condensed ring in which two or three aromatic rings are condensed to a bicycloalkane is preferable, and a group containing a condensed ring in which two or three aromatic rings are condensed to bicyclo[2.2.2]octane is more preferable. R 101 Specific examples of the condensed cyclic group in include those represented by the following formulas (r-br-1) to (r-br-2). In the formula, * represents a bond that binds to Y in the formula (b-1) 101

[0233]

Chemical formula

[0234] R 101 Examples of the substituent that the condensed cyclic group in 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 condensed cyclic group are as described above for R 101 ​Those similar to those listed as the substituents of the cyclic group can be mentioned. Examples of the aromatic hydrocarbon group as the substituent of the condensed cyclic group include a group obtained by removing one hydrogen atom from an aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring is 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.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6), respectively. Examples of the alicyclic hydrocarbon group as the substituent of the condensed cyclic group include a group obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane and cyclohexane; a group obtained by removing one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), respectively; -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively; and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16), respectively.

[0235] A chain alkyl group which may have a substituent: R 101 The chain alkyl group of may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched-chain alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, etc. can be mentioned.

[0236] A chain alkenyl group which may have a substituent: R 101 The chain alkenyl group may be linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include vinyl group, propenyl group (allyl group), butenyl group, etc. Examples of the branched alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group, etc. Among them, the linear alkenyl group is preferred as the chain alkenyl group, the vinyl group and the propenyl group are more preferred, and the vinyl group is particularly preferred.

[0237] R 101 Examples of the substituent in the chain alkyl group or alkenyl group of R include alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, carbonyl group, nitro group, amino group, and the cyclic group in the above R 101 etc.

[0238] Among them, R 101 preferably has a cyclic group which may have a substituent, and more preferably is a cyclic hydrocarbon group which may have a substituent. More specifically, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7) respectively; a -SO2-containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4) respectively, etc. are preferred.

[0239] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 When Y is a divalent linking group containing an oxygen atom, the Y 101 may contain atoms other than the oxygen atom. Examples of the atoms other than the oxygen atom include carbon atom, hydrogen atom, sulfur atom, nitrogen atom, etc. Examples of the divalent linking group containing an oxygen atom include non-hydrocarbon-based oxygen atom-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), a carbonate bond (-O-C(=O)-O-), etc.; combinations of the non-hydrocarbon-based oxygen atom-containing linking group and an alkylene group, etc. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of the divalent linking group containing an oxygen atom include linking groups represented by the following general formulas (y-al-1) to (y-al-7), respectively.

[0240] [Chemical formula] [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.]

[0241] The divalent saturated hydrocarbon group in V’ 102 is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0242] The alkylene group in V’ 101 and V’ 102 may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred. V’ 101 and V’ 102As the alkylene group in, specifically, methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene group [-CH2CH2-]; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-; trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; tetramethylene group [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-; pentamethylene group [-CH2CH2CH2CH2CH2-] and the like can be mentioned. Also, V’ 101 Or V’ 102 In, 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 the cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group) of Ra’ in the formula (a1-r-1) 3 A divalent group obtained by further removing one hydrogen atom from is preferable, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferable.

[0243] Y 101 As, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, and the linking groups respectively represented by the above formulas (y-al-1) to (y-al-5) are more preferable.

[0244] In the formula (b-1), V 101 Is a single bond, an alkylene group or a fluorinated alkylene group. The alkylene group and the fluorinated alkylene group in V 101 Preferably have 1 to 4 carbon atoms. As the fluorinated alkylene group in V 101 In, 101Examples thereof include a group in which some or all of the hydrogen atoms of the alkylene group are substituted with fluorine atoms. Among them, V 101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0245] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0246] · 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-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same as R 101 in formula (b-1). However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105 are preferably a chain-like alkyl group which may have a substituent, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The carbon number of the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. The carbon number of the chain-like alkyl group of R 104 , R 105 is preferably smaller within the above carbon number range for reasons such as good solubility in the resist solvent. Also, R 104 , R 105In the case of the chain alkyl group, the larger the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and it is preferable because the transparency to high-energy light or electron beams of 250 nm or less is improved. The ratio of fluorine atoms in the chain alkyl group, that is, 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 examples thereof are the same as those of V 101 in formula (b-1). In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0247] · 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 examples thereof are the same as those of R 101 in formula (b-1). In formula (b-3), L 103 ~L 105 are each independently a single bond, -CO- or -SO2-.

[0248] Among the above, as the anion part of component (B), the anion of component (b-1) is preferable, and it is more preferable that it is an anion represented by the following general formula (b0-an-1) or an anion represented by the following general formula (b0-an-2).

[0249] [Chemical formula] [In formula (b0-an-1), R b01 is a condensed cyclic group containing a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed, which may have a substituent. R102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 is a single bond, an alkylene group or a fluorinated alkylene group. In formula (b0-an-2), R b02 is a polycyclic alicyclic hydrocarbon group having at least one hydroxy group as a substituent. R 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 is a single bond, an alkylene group or a fluorinated alkylene group.]

[0250] R in the general formula (b0-an-1) b01 is a condensed ring group containing a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring which may have a substituent are condensed. As the condensed ring, the same as the condensed ring group containing a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring in R 101 in the (b-1) component described above are condensed can be mentioned. Among them, R b01 is preferably a group represented by the above formula (r-br-1) or (r-br-2).

[0251] The substituent in the above condensed ring of the above R b01 is the same as the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, hydroxy group, carbonyl group, nitro group, -C(=O)OR 101 exemplified as the substituent in the cyclic group of R, -C(=O)OR XYZ , -OC(=O)R XYZ (R XYZ is a lactone-containing cyclic group, a carbonate-containing cyclic group or a -SO2-containing cyclic group) and the like. Among them, as the substituent in the above condensed ring of the above R b01 , -C(=O)OR XYZ is preferable, and a group in which R XYZ in -C(=O)OR xyz is a lactone-containing cyclic group is more preferable.

[0252] R in the general formula (b0 - an - 2) b02 is a polycyclic alicyclic hydrocarbon group having at least one hydroxy group as a substituent. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferable, and as the polycycloalkane, those having 7 to 30 carbon atoms are preferable. Among them, as the polycycloalkane, polycycloalkanes having a crosslinked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane; polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferable.

[0253] Among them, R b02 as the polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, more preferably an adamantyl group or a norbornyl group, and even more preferably an adamantyl group.

[0254] R b02 The polycyclic alicyclic hydrocarbon group in has at least one hydroxy group. The polycyclic alicyclic hydrocarbon group in R b02 may have a substituent other than the hydroxy group. Examples of the substituent other than the hydroxy group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a carbonyl group, a nitro group, etc. R in the general formula (b0 - an - 2) b02 is preferably a polycyclic alicyclic hydrocarbon group having one hydroxy group as a substituent, and more preferably an adamantyl group having one hydroxy group as a substituent, among the above.

[0255] As the anion part of the component (B) in the resist composition of this embodiment, among the above, an anion represented by the following general formula (b0 - an - 1 - 1) is more preferable.

[0256]

Chemical formula

Chemical formula

[0257]

Chemical formula

[0258] In the above general formula (b0-an-1-1), Rx 5 and Rx 6 , and Rz 1 ~Rz 4 As the hydrocarbon group in, the R of the above-mentioned component (b-1) 101Examples thereof include a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, and a linear alkenyl group which may have a substituent. As the cyclic group, -C(=O)OR XYZ , -OC(=O)R XYZ Regarding, R XYZ wherein is a lactone-containing cyclic group, a carbonate-containing cyclic group or a -SO2-containing cyclic group is also included. -C(=O)OR XYZ , and -OC(=O)R XYZ Examples of the lactone-containing cyclic group, -SO2-containing cyclic group, and carbonate-containing cyclic group in are preferably groups represented by the general formulas (a2-r-1) to (a2-r-7), groups represented by the general formulas (a5-r-1) to (a5-r-4), and groups represented by the general formulas (ax3-r-1) to (ax3-r-3), respectively.

[0259] In the above general formula (b0-an-1-1), Rz 1 ~Rz 4 Two or more of them may be bonded to each other to form a ring structure. For example, Rz 1 may form a ring structure with any of Rz 2 ~Rz 4 . Specifically, a ring structure sharing a bond (the bond between the carbon atom to which Rz 1 and Rz 2 are bonded and the carbon atom to which Rz 3 and Rz 4 are bonded) on one side of the six-membered ring in the formula (b0-an-1-1), a ring structure formed by bonding Rz 1 and Rz 2 , a ring structure formed by bonding Rz 3 and Rz 4 and the like can be mentioned. Such a ring structure formed by two or more of Rz 1 ~Rz 4 may be an alicyclic hydrocarbon or an aromatic hydrocarbon, and is particularly preferably an aromatic hydrocarbon. Further, this ring structure may be a polycyclic structure composed of other ring structures.

[0260] In the anion group represented by the general formula (b0-r-an1), R 102 , Y 101 , and V 101 are the same as R 102 , Y 101 , and V 101 in the component (b-1), respectively.

[0261] In the general formula (b0-an-1-1), Rx 5 , and Rx 6 are preferably hydrogen atoms among the above. In the general formula (b0-an-1-1), Rz 1 to Rz 4 are preferably hydrogen atoms or -C(=O)OR XYZ , -OC(=O)R XYZ for which R XYZ is a lactone-containing cyclic group. The lactone-containing cyclic group is preferably a group represented by the above formula (a2-r-2). n1 is preferably an integer of 1 to 3, preferably 1 or 2, and more preferably 1. n11 and n21 are preferably 0. n2 is preferably an integer of 1 to 3, preferably 1 or 2, and more preferably 1.

[0262] Specific preferred examples of the anion part of the component (B) in the resist composition of this embodiment are shown below.

[0263]

Chemical formula

[0264] {Cation part} In the above formulas (b-1), (b-2), and (b-3), M' m+ represents an m-valent onium cation. Among these, a sulfonium cation and an iodonium cation are preferred. m is an integer of 1 or more.

[0265] Preferred cationic moiety ((M’ m+ ) 1 / m ) includes organic cations represented by the following general formulas (ca-1) to (ca-5).

[0266] [Chemical formula] [In the formula, R 201 ~R 207 , and R 211 ~R 212 each independently represent an aryl group, an alkyl group or an alkenyl group which may have a substituent. R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 may be bonded to each other to form a ring together with the sulfur atom in the formula. R 208 ~R 209 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a SO2-containing cyclic group which may have a substituent. L 201 represents -C(=O)- or -C(=O)-O-. Y 201 each independently represent an arylene group, an alkylene group or an alkenylene group. x is 1 or 2. W 201 represents an (x + 1)-valent linking group.]

[0267] In the above general formulas (ca-1) to (ca-5), examples of the aryl group in R 201 ~R 207 , and R 211 ~R 212 include unsubstituted aryl groups having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferred. R 201 ~R 207 , and R 211 ~R 212The alkyl group in [the compound] is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 and R 211 ~R 212 The alkenyl group in [the compound] preferably has 2 to 10 carbon atoms. R 201 ~R 207 and R 210 ~R 212 Examples of the substituent that [R

[0268]

Chemical formula

[0269] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Also, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0270] R’ 201 The aromatic hydrocarbon group in [R’ R’ 201Specific examples of the aromatic ring in the aromatic hydrocarbon group include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. R’ 201 Specific examples of the aromatic hydrocarbon group in include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0271] R’ 201 The cyclic aliphatic hydrocarbon group in includes an aliphatic hydrocarbon group containing a ring in its structure. Examples of the aliphatic hydrocarbon group containing a ring in this structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, etc. 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. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from monocycloalkane is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentane, cyclohexane and the like can be mentioned. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from polycycloalkane is preferable, and as the polycycloalkane, those having 7 to 30 carbon atoms are preferable. Among them, as the polycycloalkane, polycycloalkanes having a crosslinked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane; polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferable.

[0272] Among them, R’ 201 As the cyclic aliphatic hydrocarbon group in, a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane is preferable, a group obtained by removing one hydrogen atom from polycycloalkane is more preferable, an adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

[0273] 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 linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-] and the like can be mentioned. As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferred. Specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2- and other alkylalkylene groups can be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0274] Also, R’ 201 The cyclic hydrocarbon group in may contain a hetero atom such as a heterocyclic ring. Specifically, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16) can be mentioned.

[0275] R’ 201 Examples of the substituent in the cyclic group of include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, and the like. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferred, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferred. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are most preferred. As the halogen atom as the substituent, a fluorine atom is preferred. Examples of the alkyl halide group as a substituent include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, are substituted with the halogen atom. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) constituting a cyclic hydrocarbon group.

[0276] Chain-like alkyl group which may have a substituent: R’ 201 The chain-like alkyl group of may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched-chain alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, etc. may be mentioned.

[0277] Chain-like alkenyl group which may have a substituent: R’ 201 The chain-like alkenyl group of may be either linear or branched, preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still 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), a butynyl group, etc. Examples of the branched-chain alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, a 2-methylpropenyl group, etc. Among them, the linear alkenyl group is preferred as the chain-like alkenyl group, the vinyl group and the propenyl group are more preferred, and the vinyl group is particularly preferred.

[0278] R’ 201 Examples of the substituent in the chain-like alkyl group or alkenyl group of 201 201 include, for example, 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’

[0279] R’ 201 The cyclic group which may have a substituent, the chain-like alkyl group which may have a substituent, or the chain-like alkenyl group which may have a substituent, in addition to those described above, as the cyclic group which may have a substituent or the chain-like alkyl group which may have a substituent, also includes those similar to the acid dissociable group represented by the above formula (a1-r-2).

[0280] 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 obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7) respectively; a -SO2-containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4) respectively, etc. are preferable.

[0281] In the above general formulas (ca-1) to (ca-5), when R 201 ~R 203 、R 206 ~R 207 、R 211 ~R 212 are bonded to each other to form a ring together with the sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom, a nitrogen atom, or a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH- or -N(R N )-(the R Nis an alkyl group having 1 to 5 carbon atoms. It may be bonded via a functional group such as). As the ring formed, it is preferable that one ring containing the sulfur atom in the formula in its ring skeleton is a 3- to 10-membered ring including the sulfur atom, and particularly preferably a 5- to 7-membered ring. Specific examples of the formed ring include, for example, thiophene ring, thiazole ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydrothiophenium ring, tetrahydrothiopyranium ring and the like.

[0282] 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 it is an alkyl group, they may be bonded to each other to form a ring.

[0283] R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a SO2-containing cyclic group which may have a substituent. R 210 Examples of the aryl group in R include unsubstituted aryl groups having 6 to 20 carbon atoms, and preferably a phenyl group and a naphthyl group. R 210 Examples of the alkyl group in R include linear or cyclic alkyl groups, preferably those having 1 to 30 carbon atoms. R 210 Examples of the alkenyl group in R preferably have 2 to 10 carbon atoms. R 210 Examples of the SO2-containing cyclic group which may have a substituent in R preferably include a "-SO2-containing polycyclic group", and more preferably a group represented by the above general formula (a5-r-1).

[0284] Y 201 each independently represents an arylene group, an alkylene group or an alkenylene group. Y 201 The arylene group in Y is R in the above formula (b-1) 101Examples thereof include a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group in [ ]. Y 201 In [ ], the alkylene group and alkenylene group are the R in the above formula (b-1). 101 Examples thereof include a group obtained by removing one hydrogen atom from the groups exemplified as the linear alkyl group and linear alkenyl group in [ ].

[0285] In the formula (ca-4), x is 1 or 2. W 201 is a (x + 1)-valent, that is, a divalent or trivalent linking group. W 201 As the divalent linking group in [ ], a divalent hydrocarbon group which may have a substituent is preferable, and examples thereof include the same divalent hydrocarbon group which may have a substituent as Ya in the above general formula (a2-1). W 21 The divalent linking group in [ ] may be linear, branched or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable. W 201 Examples of the trivalent linking group in [ ] include a group obtained by removing one hydrogen atom from the divalent linking group in the above W 201 and a group in which the above divalent linking group is further bonded to the divalent linking group. W 201 Examples of the trivalent linking group in [ ] include a group in which two carbonyl groups are bonded to an arylene group. 201

[0286] Specific examples of the preferable cation represented by the formula (ca-1) are shown below.

[0287]

Chemical formula

[0288] ​​

[0289]

Chem.

[0290]

Chem.

[0291]

Chem.

[0292]

Chem.

[0293]

Chem.

[0294]

Chem.

[0295]

Chem.

[0296]

Chem.

[0297] Specific examples of the preferred cation represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0298] Specific examples of the preferred cation represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6), respectively.

[0299]

Chemical formula

[0300] Specific examples of the preferred cation represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2), respectively.

[0301]

Chemical formula

[0302] As the cation represented by the formula (ca-5), cations represented by the following general formulas (ca-5-1) to (ca-5-3) are also preferred.

[0303]

Chemical formula

[0304] Among the above, the cation part ((M’ m+ )) 1 / m ) is preferably a cation represented by the general formula (ca-1).

[0305] In the resist composition of this embodiment, the component (B) is preferably a compound represented by the following general formula (b0-1) or a compound represented by the following general formula (b0-2) among the above.

[0306]

Chemical formula

[0307] The anion part of the compound represented by the general formula (b0-1) is the same as the anion represented by (b0-an-1) described above. The anion part of the compound represented by the general formula (b0-2) is the same as the anion represented by (b0-an-2) described above.

[0308] The cation parts (M’ m+ ) in the compound represented by the general formula (b0-1) and the compound represented by the general formula (b0-2) are the same as those of the cation part of the component (b-1) described above, respectively.

[0309] Among the above, the component (B) in the resist composition of the present embodiment is more preferably a compound represented by the following general formula (b0-1-1).

[0310]

Chemical formula

[0311] [Chemical formula] [In the formula, R 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 is a single bond, an alkylene group or a fluorinated alkylene group. ]

[0312] The anion part of the compound represented by the above general formula (b0-1-1) is the same as the anion represented by (b0-an-1-1) described above. The cation part (M’ m+) includes those similar to the cation part of the component (b-1) described above respectively.

[0313] Specific preferred examples of the component (B) in the resist composition of the present embodiment are shown below.

[0314]

Chemical formula

[0315]

Chemical formula

[0316]

Chemical formula

[0317]

Chemical formula

[0318] Among the above, the component (B) is more preferably a compound represented by any of the above formulas (B-1-1) to (B-1-3), (B-1-5), (B-1-7) to (B-1-13), and even more preferably a compound represented by any of the above formulas (B-1-1) to (B-1-3), (B-1-5), (B-1-7).

[0319] In the resist composition of the present embodiment, the component (B) may be used alone or in combination of two or more. When the resist composition contains the component (B), in the resist composition, the content of the component (B) is 20 parts by mass or more, preferably 20 parts by mass or more and 50 parts by mass or less, and more preferably 20 parts by mass or more and 45 parts by mass or less with respect to 100 parts by mass of the component (A). By setting the content of component (B) to 20 parts by mass or more, the amount of acid generated by exposure increases, and the variation in the distribution of the generated acid becomes smaller, so that the lithography characteristics are improved. Further, by setting the content of component (B) to be equal to or less than the upper limit value of the above-mentioned preferable range, the variation in the distribution of the generated acid becomes smaller, so that the lithography characteristics are more likely to be improved.

[0320] <Photodegradable base component (D1)> In addition to components (A) and (B), the resist composition of the present embodiment further contains a photodegradable base component (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure and loses acid diffusion controllability. By using a resist composition containing component (D1), the contrast between the exposed portion and the unexposed portion of the resist film can be further improved when forming a resist pattern. The component (D1) is not particularly limited as long as it decomposes upon exposure and loses acid diffusion controllability, and is preferably at least one compound 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)"). Components (d1-1) to (d1-3) do not act as a quencher because they decompose in the exposed portion of the resist film and lose acid diffusion controllability (basicity), and act as a quencher in the unexposed portion of the resist film.

[0321] [Chemical formula] [In the formula, Rd 1 ~Rd 4 is a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. However, it is assumed that a fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd 2 in formula (d1-2). Yd 1is a single bond or a divalent linking group. m is an integer of 1 or more, and M m+ is each independently an m-valent organic cation.]

[0322] {(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 above R’ 201 is the same as those described above. Among these, as Rd 1 a substituted aromatic hydrocarbon group, a substituted aliphatic cyclic group, or a substituted chain alkyl group is preferable. Examples of the substituents that 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 included as a substituent, it may be via an alkylene group, and in this case, a linking group represented by the above formulas (y-al-1) to (y-al-5) is preferable as the substituent. Examples of the aromatic hydrocarbon group preferably include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure composed of a bicyclooctane skeleton and another ring structure). The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The linear alkyl group preferably has 1 to 10 carbon atoms. Specifically, examples include linear alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group; branched alkyl groups such as 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0323] When the linear alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 4 carbon atoms. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include an oxygen atom, a sulfur atom, and a nitrogen atom. Rd 1 is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted by fluorine atoms, and particularly preferably a fluorinated alkyl group in which all of the hydrogen atoms constituting the linear alkyl group are substituted by fluorine atoms (linear perfluoroalkyl group).

[0324] Preferred specific examples of the anion part of the component (d1-1) are shown below.

[0325]

Chemical formula

[0326] ··· Cation part In formula (d1-1), M m+ is an m-valent organic cation. M m+ Examples of the organic cation of M preferably include the same cations as those represented by the general formulas (ca-1) to (ca-4) respectively, and the cation represented by the general formula (ca-1) is more preferred. (Component (d1-1) may be used alone or in combination of two or more thereof.)

[0327] {(Component (d1-2))} ··Anionic part In formula (d1-2), Rd 2 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and the above R’ 201 is the same as those mentioned above. However, it is assumed that a fluorine atom is not bonded (not fluorine-substituted) to the carbon atom adjacent to the S atom in Rd 2 . Thereby, the anion of component (d1-2) becomes a moderately weak acid anion, and the quenching ability as component (D) is improved. Rd 2 is preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. As the chain alkyl group, it is preferably having 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. As the aliphatic cyclic group, a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent); a group obtained by removing one or more hydrogen atoms from camphor, etc. is more preferable. Rd 2 The hydrocarbon group of may have a substituent, and examples of the substituent include the same substituents as those which the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in Rd 1 in formula (d1-1) may have.

[0328] The following shows preferred specific examples of the anionic part of component (d1-2).

[0329]

Chemical formula

[0330] ··Cationic part In formula (d1-2), M m+ is an m-valent organic cation, which is the same as M in the formula (d1-1). m+ The same applies. (Component (d1-2) may be used alone or in combination of two or more.

[0331] {(Component (d1-3))} ·· Anion part In formula (d1-3), Rd 3 is an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group, and examples thereof are the same as those of R' 201 , and it is preferably a cyclic group, a linear alkyl group, or a linear alkenyl group containing a fluorine atom. Among them, a fluorinated alkyl group is preferable, and more preferably the same as the fluorinated alkyl group of Rd 1 .

[0332] In formula (d1-3), Rd 4 is an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group, and examples thereof are the same as those of R' 201 . Among them, it is preferably an optionally substituted alkyl group, alkoxy group, alkenyl group, or cyclic group. Rd 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples thereof include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. A part of the hydrogen atoms of the alkyl group in Rd 4 may be substituted with a hydroxyl group, a cyano group, etc. Rd 4 The alkoxy group in Rd is preferably an alkoxy group having 1 to 5 carbon atoms. Specifically, examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert-butoxy group. Among them, methoxy group and ethoxy group are preferable.

[0333] Rd 4 The alkenyl group in is the same as the alkenyl group in the aforementioned R'. 201 Examples of the alkenyl group in include the same as those of the alkenyl group in the aforementioned R', and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group are preferable. These groups may further have, as a substituent, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

[0334] Rd 4 The cyclic group in is the same as the cyclic group in the aforementioned R'. 201 Examples of the cyclic group in include the same as those of the cyclic group in the aforementioned R', and an alicyclic group obtained by removing one or more hydrogen atoms from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane, or an aromatic group such as a phenyl group or a naphthyl group is preferable. When Rd 4 is an alicyclic group, the resist composition dissolves well in an organic solvent, and thus the lithography characteristics are good. Also, when Rd 4 is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition has excellent light absorption efficiency, and the sensitivity and lithography characteristics are good.

[0335] 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, and examples include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a heteroatom, and the like. These are respectively the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a heteroatom, which were mentioned in the description of the divalent linking group in Ya 21 in the above formula (a2-1). Yd 1Preferably, it is a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. As the alkylene group, a linear or branched alkylene group is more preferable, and a methylene group or an ethylene group is even more preferable.

[0336] Specific preferred examples of the anionic part of the component (d1-3) are shown below.

[0337]

Chemical formula

[0338]

Chemical formula

[0339] ···Cationic part In formula (d1-3), M m+ is an m-valent organic cation, which is the same as M in the above formula (d1-1). m+ The component (d1-3) may be used alone or in combination of two or more.

[0340] The component (D1) may use only any one of the above components (d1-1) to (d1-3), or may use a combination of two or more. Among them, as the component (D1), the component (d1-1) is preferable, and Rd in formula (d1-1) 1 is a compound having an aromatic hydrocarbon group having a substituent or a cyclic group having a polycyclic structure containing a bicyclooctane skeleton. When the resist composition contains the component (D1), in the resist composition, the content of the component (D1) is 5 parts by mass or more, preferably 5 parts by mass or more and 30 parts by mass or less, more preferably 5 parts by mass or more and 20 parts by mass or less, and even more preferably 5 parts by mass or more and 16 parts by mass or less with respect to 100 parts by mass of the component (A). ​When the content of the component (D1) is 5 parts by mass or more, particularly good lithography characteristics and resist pattern shapes are likely to be obtained. On the other hand, when the content of the component (D1) is equal to or less than the upper limit value of the above-mentioned preferred range, the sensitivity can be maintained well and the throughput is also excellent.

[0341] Production method of the component (D1): The production methods of the above-mentioned components (d1-1) and (d1-2) are not particularly limited and can be produced by known methods. Also, the production method of the component (d1-3) is not particularly limited and is produced, for example, in the same manner as the method described in US2012-0149916.

[0342] In the resist composition of the present embodiment, the total content of the acid generator component (B) and the photo-dissociable base (D1) is 25 parts by mass or more, preferably 25 parts by mass or more and 65 parts by mass or less, and more preferably 27 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the base material component (A).

[0343] Also, in the resist composition of the present embodiment, the mass ratio of the acid generator component (B) to the photo-dissociable base (D1) (acid generator component (B) / photo-dissociable base (D1)) is preferably 1.5 to 6.0, and more preferably 2.0 to 5.0.

[0344] <Other components> The resist composition of the present embodiment may further contain other components in addition to the above-mentioned components (A), (B), and (D1). Examples of the other components include the following components (B), (D2) components (base components other than the component (D1)), (E) components, (F) components, (S) components, and the like.

[0345] ≪Regarding the component (D2)≫ As the component (D), it may contain a nitrogen-containing organic compound component that does not correspond to the above-mentioned component (D1) (hereinafter referred to as the "component (D2)"). (D2) component is not particularly limited as long as it acts as an acid diffusion controller and does not correspond to (D1) component, and it may be arbitrarily used from known ones. Among them, aliphatic amines are preferred, and among them, secondary aliphatic amines and tertiary aliphatic amines are more preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of aliphatic amines include amines (alkylamines or alkyl alcohol amines) in which at least one hydrogen atom of ammonia NH3 is substituted with an alkyl group or a hydroxyalkyl group having 12 or fewer carbon atoms, or cyclic amines. Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0346] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine). Specific examples of aliphatic monocyclic amines include piperidine and piperazine. As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable, and specifically, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane and the like can be mentioned.

[0347] As other aliphatic amines, tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate and the like can be mentioned, and triethanolamine triacetate is preferable.

[0348] Further, as the component (D2), an aromatic amine may be used. Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine and the like.

[0349] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), in the resist composition, the content of the component (D2) is usually used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A). By setting it within the above range, the resist pattern shape, the stability over time of standing, etc. are improved.

[0350] ≪At least one compound (E) selected from the group consisting of an organic carboxylic acid, an oxo acid of phosphorus and its derivatives≫ In the resist composition of this embodiment, for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, standing stability over time, etc., as an optional component, an organic carboxylic acid and at least one compound (E) selected from the group consisting of oxo acids of phosphorus and their derivatives (hereinafter referred to as "(E) component") can be contained. As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc. are suitable. Examples of the oxo acids of phosphorus include phosphoric acid, phosphonic acid, phosphinic acid, etc., and among these, phosphonic acid is particularly preferred. Examples of the derivatives of the oxo acids of phosphorus include esters in which the hydrogen atom of the above oxo acid is substituted with a hydrocarbon group, and examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 15 carbon atoms, etc. Examples of the derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate. Examples of the derivatives of phosphonic acid include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, dibenzyl phosphonate, etc. Examples of the derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid. In the resist composition of this embodiment, the (E) component may be used alone or in combination of two or more. When the resist composition contains the (E) component, the content of the (E) component is usually used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the (A) component.

[0351] ≪Fluorine additive component (F)≫ The resist composition of this embodiment may contain a fluorine additive component (hereinafter referred to as "(F) component") in order to impart water repellency to the resist film or to improve lithography characteristics. (F) component, for example, can use fluorine-containing polymer compounds described in JP-A No. 2010-002870, JP-A No. 2010-032994, JP-A No. 2010-277043, JP-A No. 2011-13569, and JP-A No. 2011-128226. (F) component more specifically includes polymers having a structural unit (f1) represented by the following general formula (f1-1). As this polymer, a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1); a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1) is preferred. Here, as the structural unit (a1) copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate and a structural unit derived from 1-methyl-1-adamantyl (meth) acrylate are preferred.

[0352] [Chemical formula] [In the formula, R is the same as above, 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, and Rf 102 and Rf 103 may be the same or different. nf 1 is an integer of 0 to 5, and Rf 101 is an organic group containing a fluorine atom.]

[0353] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as above. As R, a hydrogen atom or a methyl group is preferred. In formula (f1-1), Rf 102 and Rf 103 halogen atoms include fluorine atom, chlorine atom, bromine atom, iodine atom, etc., and fluorine atom is particularly preferred. Rf 102 and Rf 103Examples of the alkyl group having 1 to 5 carbon atoms include the same ones as the alkyl group having 1 to 5 carbon atoms of R above, and a methyl group or an ethyl group is preferred. Rf 102 and Rf 103 Examples of the halogenated alkyl group having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferred. Among them, Rf 102 and Rf 103 are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group is preferred. In formula (f1-1), nf 1 is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0354] In formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom. Examples of the hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, preferably having 1 to 20 carbon atoms, more preferably having 1 to 15 carbon atoms, and particularly preferably having 1 to 10 carbon atoms. In addition, in the hydrocarbon group containing a fluorine atom, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferably 60% or more are fluorinated because the hydrophobicity of the resist film during immersion exposure increases. 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, -CH2-CH2-CF2-CF2-CF2-CF3.

[0355] The weight average molecular weight (Mw) (in terms of polystyrene conversion standard by gel permeation chromatography) of component (F) is preferably from 1,000 to 50,000, more preferably from 5,000 to 40,000, and most preferably from 10,000 to 30,000. When it is below the upper limit value of this range, there is sufficient solubility in the resist solvent for use as a resist composition, and when it is above the lower limit value of this range, the water repellency of the resist film is good. The dispersity (Mw / Mn) of 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.

[0356] In the resist composition of this embodiment, component (F) may be used alone or in combination of two or more. When the resist composition contains component (F), the content of component (F) is usually used in a proportion of 0.5 to 10 parts by mass with respect to 100 parts by mass of component (A).

[0357] ≪Organic solvent component (S)≫ The resist composition of this embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as “component (S)”). As component (S), any one can be appropriately selected from those known as solvents for chemically amplified resist compositions as long as it can dissolve each component used and form a uniform solution. Examples of the component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, monomethyl ethers, monoethyl ethers, monopropyl ethers, monobutyl ethers, etc. of the above polyhydric alcohols or compounds having an ester bond, or compounds having an ether bond such as monophenyl ether, etc., derivatives of polyhydric alcohols [among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethyl benzene, diethyl benzene, pentyl benzene, isopropyl benzene, toluene, xylene, cymene, mesitylene, etc., dimethyl sulfoxide (DMSO), etc. In the resist composition of this embodiment, the component (S) may be used alone or as a mixed solvent of two or more kinds. Among them, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0358] Also, as the component (S), a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, etc., but it is preferably in the range of 1:9 to 9:1, more preferably 2:8 to 8:2. More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is blended as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferable. In addition, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio is preferably such that the mass ratio of the former to the latter is 70:30 to 95:5. The usage amount of the (S) component is not particularly limited and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. Generally, the (S) component is used so that the solid content concentration of the resist composition is within the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0359] In the resist composition of this embodiment, additives having miscibility as desired, such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc., can be appropriately added and contained.

[0360] After dissolving the above resist material in the (S) component, the resist composition of this embodiment may be subjected to removal of impurities or the like using a polyimide porous membrane, a polyamideimide porous membrane, or the like. For example, filtration of the resist composition may be performed using a filter made of a polyimide porous membrane, a filter made of a polyamideimide porous membrane, a filter made of a polyimide porous membrane and a polyamideimide porous membrane, or the like. Examples of the polyimide porous membrane and the polyamideimide porous membrane include those described in JP-A-2016-155121.

[0361] The resist composition of the present embodiment described above contains a resin component (A1) having a constitutional unit (a01) and a constitutional unit (a02), and contains the component (B) and the component (D1) in relatively larger amounts than conventional resist compositions. Since the constitutional unit (a02) has an aromatic ring hydroxy group that acts as a proton source, the amount of acid generated from the component (B) can be increased. Further, by increasing the content of the component (B), the amount of acid generated can be further increased, and the variation in the distribution of the generated acid can be reduced. Furthermore, by increasing the content of the component (D1), the contrast between the exposed portion and the unexposed portion of the resist film can be further improved. On the other hand, the constitutional unit (a01) may have an aromatic hydrocarbon group (Ra 01 ) bonded to the tertiary carbon atom bonded to the carbonyloxy group (C(=O)-O-) in the formula (a01-1), so the reactivity of the deprotection reaction is enhanced. Due to these synergistic effects, the resist composition of the present embodiment can perform resolution as per the optical image of the exposure apparatus and can form a resist pattern with further reduced roughness.

[0362] (Resist pattern forming method) The resist pattern forming method according to the second aspect of the present invention is a method having a step of forming a resist film on a support using the resist composition of the above-described embodiment, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern. As an embodiment of such a resist pattern forming method, for example, a resist pattern forming method performed as follows can be mentioned.

[0363] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and a bake (post-apply bake (PAB)) treatment is performed at a temperature condition of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film. Next, selective exposure is performed on the resist film, for example, by exposure through a mask (mask pattern) on which a predetermined pattern is formed or by direct irradiation with an electron beam without using a mask pattern using an exposure apparatus such as an electron beam lithography apparatus or an EUV exposure apparatus. After that, a baking (post-exposure baking (PEB)) process is performed at a temperature condition of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds. Next, the resist film is developed. In the case of an alkali development process, an alkali developer is used, and in the case of a solvent development process, a developer containing an organic solvent (organic-based developer) is used.

[0364] After the development process, preferably a rinsing process is performed. In the case of an alkali development process, water rinsing using pure water is preferable, and in the case of a solvent development process, it is preferable to use a rinsing liquid containing an organic solvent. In the case of a solvent development process, after the development process or the rinsing process, a process of removing the developer or rinsing liquid adhering to the pattern with a supercritical fluid may be performed. After the development process or the rinsing process, drying is performed. Also, in some cases, a baking process (post-bake) may be performed after the above development process. In this way, a resist pattern can be formed.

[0365] The support is not particularly limited, and conventionally known ones can be used. For example, substrates for electronic components and those on which a predetermined wiring pattern is formed can be mentioned. More specifically, substrates made of metals such as silicon wafers, copper, chromium, iron, and aluminum, and glass substrates can be mentioned. As materials for the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used. Also, as the support, a substrate as described above on which an inorganic and / or organic film is provided may be used. Examples of the inorganic film include an inorganic anti-reflection film (inorganic BARC). Examples of the organic film include an organic anti-reflection film (organic BARC) and organic films such as the lower organic film in the multilayer resist method. Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and patterning of the lower organic film is performed using a resist pattern formed in the upper resist film, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, since the required thickness can be ensured by the lower organic film, the resist film can be made thinner, and formation of a fine pattern with a high aspect ratio becomes possible. Basically, the multilayer resist method can be divided into a method with a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and a method with a multilayer structure of three or more layers in which one or more intermediate layers (such as a metal thin film) are provided between the upper resist film and the lower organic film (three-layer resist method).

[0366] The wavelength used for exposure is not particularly limited, and it can be performed using radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. The resist composition has high usefulness for KrF excimer laser, ArF excimer laser, EB or EUV, higher usefulness for ArF excimer laser, EB or EUV, and particularly high usefulness for EB or EUV. That is, the resist pattern forming method of the present embodiment is a particularly useful method when the step of exposing the resist film includes an operation of exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam).

[0367] The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be liquid immersion exposure (Liquid Immersion Lithography). Liquid immersion exposure is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is filled with a solvent (liquid immersion medium) having a refractive index larger than that of air in advance, and exposure (immersion exposure) is performed in that state. As the immersion medium, a solvent having a refractive index greater than that of air and less than that of the resist film to be exposed is preferred. The refractive index of such a solvent is not particularly limited as long as it is within the above range. Examples of the solvent having a refractive index greater than that of air and less than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, hydrocarbon-based solvents, and the like. Specific examples of the fluorine-based inert liquid include liquids mainly composed of fluorine-based compounds such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, and C5H3F7. Those having a boiling point of 70 to 180 ° C are preferred, and those having a boiling point of 80 to 160 ° C are more preferred. It is preferable that the fluorine-based inert liquid has a boiling point within the above range because the medium used for immersion can be removed by a simple method after the exposure is completed. As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferred. Specific examples of the perfluoroalkyl compound include perfluoroalkyl ether compounds and perfluoroalkylamine compounds. More specifically, examples of the perfluoroalkyl ether compound include perfluoro(2-butyl-tetrahydrofuran) (boiling point 102 ° C), and examples of the perfluoroalkylamine compound include perfluorotributylamine (boiling point 174 ° C). From the viewpoints of cost, safety, environmental issues, versatility, etc., water is preferably used as the immersion medium.

[0368] Examples of the alkaline developer used for development in the alkaline development process include an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH). As the organic solvent contained in the organic developing solution used for development processing in the solvent development process, any organic solvent that can dissolve the component (A) (component (A) before exposure) may be used, and it can be appropriately selected from known organic solvents. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, ether solvents, and hydrocarbon solvents can be mentioned. Ketone solvents are organic solvents containing C-C(=O)-C in their structure. Ester solvents are organic solvents containing C-C(=O)-O-C in their structure. Alcohol solvents are organic solvents containing an alcoholic hydroxyl group in their structure. The "alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile solvents are organic solvents containing a nitrile group in their structure. Amide solvents are organic solvents containing an amide group in their structure. Ether solvents are organic solvents containing C-O-C in their structure. Among organic solvents, there are also organic solvents containing multiple types of functional groups characterizing the above-mentioned solvents in their structure. In that case, it shall be regarded as belonging to any solvent type containing the functional groups possessed by the organic solvent. For example, diethylene glycol monomethyl ether shall be regarded as belonging to both alcohol solvents and ether solvents in the above classification. Hydrocarbon solvents are composed of hydrocarbons that may be halogenated and are hydrocarbon solvents having no substituents other than halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., and fluorine atoms are preferred. As the organic solvent contained in the organic developing solution, among the above, polar solvents are preferred, and ketone solvents, ester solvents, nitrile solvents, etc. are preferred.

[0369] Examples of the ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), and the like. Among these, methyl amyl ketone (2-heptanone) is preferable as the ketone solvent.

[0370] Examples of the ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, etc. Among these, butyl acetate is preferred as the ester solvent.

[0371] Examples of the nitrile solvent include acetonitrile, propionitrile, valeronitrile, butyronitrile and the like.

[0372] Known additives can be incorporated into the organic developer as needed. Examples of the additive include surfactants. The surfactant is not particularly limited, and for example, ionic and / or nonionic fluorine-based and / or silicon-based surfactants can be used. As the surfactant, a nonionic surfactant is preferred, and a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant is more preferred. When incorporating a surfactant, the amount thereof is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass based on the total amount of the organic developer.

[0373] The development process can be carried out by a known development method. For example, a method of immersing the support in the developer for a certain period of time (dip method), a method of raising the developer on the support surface by surface tension and allowing it to stand still for a certain period of time (paddle method), a method of spraying the developer on the support surface (spray method), a method of continuously discharging the developer while scanning the developer discharge nozzle at a constant speed on a support rotating at a constant speed (dynamic dispense method), etc. can be mentioned.

[0374] As the organic solvent contained in the rinse liquid used for the rinse treatment after the development process in the solvent development process, for example, among the organic solvents mentioned as the organic solvents used in the organic developer, those that are less likely to dissolve the resist pattern can be appropriately selected and used. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferred, at least one selected from alcohol solvents and ester solvents is more preferred, and alcohol solvents are particularly preferred. The alcohol-based solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol and the like can be mentioned. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol and 2-hexanol are more preferable. Any one of these organic solvents may be used alone, or two or more thereof may be used in combination. Further, it may be used in mixture with an organic solvent other than the above and water. However, considering the development characteristics, the blending amount of water in the rinse liquid is preferably 30% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and particularly preferably 3% by mass or less with respect to the total amount of the rinse liquid. Known additives can be blended in the rinse liquid as necessary. Examples of the additive include a surfactant. The surfactants are the same as those described above, and nonionic surfactants are preferable, and nonionic fluorine-based surfactants or nonionic silicone-based surfactants are more preferable. When blending a surfactant, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the rinse liquid.

[0375] The rinsing treatment (washing treatment) using the rinse liquid can be carried out by a known rinsing method. Examples of the method of the rinsing treatment include a method of continuously coating the rinse liquid on a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), a method of spraying the rinse liquid on the support surface (spray method), and the like.

[0376] According to the resist pattern forming method of the present embodiment described above, since the resist composition according to the first aspect described above is used, a resist pattern with further reduced roughness can be formed.

Example

[0377] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0378] <Synthesis Examples of Polymer Compounds (A-1) to (A-20)> Using the monomers shown below in a predetermined molar ratio, polymer compounds (A-1) to (A-20) were each synthesized by known radical polymerization. Regarding the obtained polymer compounds, 13 The copolymer composition ratio of the polymer compound determined by C-NMR (the ratio of each structural unit in the polymer compound (molar ratio)), the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement, and the molecular weight distribution (Mw / Mn) are shown together in Table 1.

[0379]

Chemical formula

[0380]

Chemical formula

[0381]

Chemical formula

[0382] The polymer compounds (A-1) to (A-20) obtained by polymerizing the above monomers respectively are shown below.

[0383]

Chemical formula

[0384]

Chemical formula

[0385]

Chem.

[0386]

Chem.

[0387]

Chem.

[0388] Note that the structural units represented by the following chemical formula (a02-1-1), the structural units represented by the following chemical formula (a02-1-2), and the structural units represented by the following chemical formula (a02-1-3) that constitute the above copolymer are structural units obtained by polymerizing the monomer represented by the above chemical formula (m02-1pre), the monomer represented by the above chemical formula (m02-2pre), and the monomer represented by the above chemical formula (m02-3pre), respectively.

[0389]

Chem.

[0390]

Table 1

[0391] <Preparation of Resist Composition> (Examples 1 to 26, Comparative Examples 1 to 12) The components shown in Tables 2 to 4 were mixed and dissolved to prepare the resist compositions of each example, respectively.

[0392]

Table 2

[0393]

Table 3

[0394] [Table 4]

[0395] In Tables 2 to 4, each abbreviation has the following meaning. The numerical value in [ ] is the blending amount (parts by mass). (A)-1 to (A)-20: The above-mentioned polymer compounds (A-1) to (A-20). (B)-1 to (B)-14: Acid generators composed of compounds represented by the following chemical formulas (B-1-1) to (B-1-14), respectively.

[0396] [Chemical formula]

[0397] [Chemical formula]

[0398] [Chemical formula]

[0399] [Chemical formula]

[0400] (D)-1 to (D)-5: Acid diffusion control agents composed of compounds represented by the following chemical formulas (D-1) to (D-5), respectively. (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 20 / 80 (mass ratio).

[0401] [Chemical formula]

[0402] [Formation of resist pattern] On an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS), each resist composition of each example was applied using a spinner, and pre-baked (PAB) at a temperature of 110 °C for 60 seconds on a hot plate and dried to form a resist film with a thickness of 35 nm. Next, using an electron beam lithography apparatus JEOL-JBX-9300FS (manufactured by JEOL Ltd.), the resist film was exposed (lithographed) at an acceleration voltage of 100 kV with a target size of a 1:1 line and space pattern (hereinafter "LS pattern") with a line width of 32 nm, and then post-exposure bake (PEB) was performed at 90 °C for 60 seconds. Subsequently, at 23 °C, using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.), alkali development was performed for 60 seconds, and then water rinsing was carried out for 15 seconds using pure water. As a result, a 1:1 LS pattern with a line width of 32 nm was formed.

[0403] [Evaluation of LWR (Line Width Roughness)] For the LS pattern formed in <Formation of Resist Pattern> above, 3σ, which is a measure indicating LWR, was determined. This is shown in Tables 5 to 7 as "LWR (nm)". "3σ" indicates three times the standard deviation (σ) (unit: nm) obtained from measuring the line positions 400 times in the longitudinal direction of the line using a scanning electron microscope (acceleration voltage 800 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). The smaller the value of this 3σ, the smaller the roughness of the line sidewall, meaning that a more uniform-width LS pattern was obtained.

[0404] [Table 5]

[0405] [Table 6]

[0406]

Table 7

[0407] From the results shown in Tables 5 to 7, it can be confirmed that the roughness of the LS pattern of the resist composition of the examples is reduced as compared with that of the resist composition of the comparative examples.

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, comprising a base material component (A) whose solubility in a developer changes due to the action of an acid, an acid generator component (B) that generates an acid upon exposure, and a photo-dissociable base component (D1), wherein the base material component (A) includes a resin component (A1) having a structural unit (a01) represented by the following general formula (a01-1) and a structural unit (a02) represented by the following general formula (a02-1), the content of the acid generator component (B) is 20 parts by mass or more with respect to 100 parts by mass of the base material component (A), and the content of the photo-dissociable base component (D1) is 5 parts by mass or more with respect to 100 parts by mass of the base material component (A) (however, excluding a resist composition containing a first polymer having a carbon atom constituting a ring structure in the main chain and having an aromatic ring and an acid dissociable group in the side chain). 【Chemical 1】 [wherein, R ０１ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms. Va ０１ is a divalent hydrocarbon group which may have an ether bond. n ａ０１ is an integer of 0 to 2. Ra ０１ is an aromatic hydrocarbon group which may have a substituent. Ra ０２ and Ra ０３ are each independently a hydrocarbon group which may have a substituent, and Ra ０２ and Ra ０３ are bonded to each other to form a ring. ] 【Chemical Formula 2】 [In the formula, R ０２ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ｘ０ is a single bond or an ester bond. Wa ｘ０ is a divalent aromatic hydrocarbon group.]

2. The resist composition according to claim 1, wherein the total content of the acid generator component (B) and the photo-dissociable base component (D1) is 27 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the base material component (A).

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

4. The resist pattern forming method according to claim 3, wherein in the step of exposing the resist film, the resist film is exposed to EUV (extreme ultraviolet light) or EB (electron beam).