TW202432530A - Resist composition, resist pattern forming method, compound and acid generator - Google Patents

Abstract

The present invention uses a substrate component that changes its solubility in a developer solution by the action of an acid, and an inhibitor composition of a compound represented by the general formula (b0). In the formula (b0), R ^b is an alkali-decomposable group. L ⁰³ is a divalent linking group. ^{Rl 0} is a cyclic organic group. ^{L 02} is a divalent linking group. ^{R m1} is a substituent. ^{L 01} is a divalent linking group or a single bond. ^{Vb 0} is an alkylene group, a fluorinated alkylene group or a single bond. ^{R 0} is a fluorinated alkylene group, a fluorine atom or a hydrogen atom. nb1 is an integer of 1 to 4, nb2 is an integer of 1 to 4, and nb3 is an integer of 0 to 3. 2≦nb1+nb2+nb3≦5. ^{M m+} represents an m-valent organic cation. m is an integer greater than 1. According to the resist composition, high sensitivity can be achieved when forming a resist pattern, and photolithography characteristics such as in-plane uniformity of pattern size and fine resolution can be improved.

Description

Resist composition, resist pattern forming method, compound and acid generator

The present invention relates to a resist composition, a resist pattern forming method, a compound and an acid generator. This case claims priority based on Special Application No. 2022-195214 filed in Japan on December 6, 2022, and the contents are hereby applied to.

In recent years, in the manufacture of semiconductor devices or liquid crystal display devices, the miniaturization of patterns is progressing rapidly due to the advancement of photolithography technology. As a method of miniaturization, the wavelength of the exposure light source is generally shortened (higher energy).

Resist materials are required to have such photolithographic properties as sensitivity to exposure light sources and resolution that can reproduce fine-scale patterns. As resist materials that meet such requirements, chemically amplified resist compositions containing a base material component that changes the solubility of a developer by the action of an acid and an acid generator component that generates an acid by exposure have been used in the past.

In the formation of resist patterns, the action of the acid generated by the acid generator component during exposure becomes one of the factors that greatly influences the photolithography characteristics. As the acid generator used in the chemically amplified resist composition, various kinds of acid generators have been proposed so far. For example, onium salt acid generators such as iodonium salts or sulfonium salts, oxime sulfonate acid generators, diazomethane acid generators, nitrobenzene sulfonate acid generators, imide sulfonate acid generators, disulfonate acid generators, etc. are known. As an onium salt acid generator, an alkylsulfonic acid ion or a fluorinated alkylsulfonic acid ion in which a part or all of the hydrogen atoms of the alkyl group are replaced by fluorine atoms is generally used as the negative ion part. The cationic part used in the onium salt acid generator mainly has an onium ion such as triphenylsulfonium. For example, Patent Document 1 discloses a resist composition containing a salt of a negative ion having a polycyclic structure containing a linked octane skeleton and an organic cation as an acid generator. According to the resist composition, high sensitivity to exposure light sources can be generated and improved lithography characteristics can be achieved. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2018-92159

[Problem solved by the invention]

As photolithography technology is further advanced and its application areas are expanded, the miniaturization of patterns is progressing rapidly. As a result, when manufacturing semiconductor components, it is necessary to have a technology that can form fine patterns with good shapes. For example, the goal is to form fine patterns of tens of nanometers by EUV (extreme ultraviolet) or EB (electron beam) lithography. In this way, the smaller the pattern size, the more it can be improved without having to balance the photolithography characteristics such as sensitivity and resolution. However, in the past resist composition mentioned above, when high sensitivity is achieved, sometimes problems such as in-plane uniformity (CDU) of pattern size and fine resolution become problems.

The present invention is made in view of the above-mentioned circumstances, and aims to provide a resist composition that can achieve high sensitivity when forming a resist pattern and improve lithography characteristics such as CDU and fine resolution, a resist pattern forming method using the resist composition, and a compound that is useful as an acid generator component used in the resist composition. [Means for solving the problem]

In order to solve the above-mentioned problem, the present invention adopts the following structure. That is, the first aspect of the present invention is a resist composition, which is characterized by generating acid by exposure and causing a change in the solubility of the developer by the action of the acid, wherein the resist composition contains a base component (A) causing a change in the solubility of the developer by the action of the acid and a compound (B0) represented by the following general formula (b0).

[In the formula, ^Rb is an alkali-decomposable group. ^L03 is a divalent linking group. ^Rl0 is a cyclic organic group which may have a substituent. ^L02 is a divalent linking group. I is an iodine atom. ^Rm1 is a substituent other than an iodine atom. ^L01 is a divalent linking group or a single bond. ^Vb0 is an alkylene group, a fluorinated alkylene group or a single bond. However, ^L01 and ^Vb0 will not simultaneously form a single bond. ^R0 is a fluorinated alkylene group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom. nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3. However, 2≦nb1+nb2+nb3≦5. ^Mm+ represents an m-valent organic cation. m is an integer greater than 1.]

The second aspect of the present invention is a method for forming a resist pattern, which is characterized by comprising the steps of forming a resist film on a support using the resist composition as described in the first aspect, exposing the resist film, and developing the exposed resist film to form a resist pattern.

A compound represented by the following general formula (b0) in the third aspect of the present invention is characterized in that:

[In the formula, ^Rb is an alkali-decomposable group. ^L03 is a divalent linking group. ^Rl0 is a cyclic organic group which may have a substituent. ^L02 is a divalent linking group. I is an iodine atom. ^Rm1 is a substituent other than an iodine atom. ^L01 is a divalent linking group or a single bond. ^Vb0 is an alkylene group, a fluorinated alkylene group or a single bond. However, ^L01 and ^Vb0 will not simultaneously form a single bond. ^R0 is a fluorinated alkylene group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom. nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3. However, 2≦nb1+nb2+nb3≦5. ^Mm+ represents an m-valent organic cation. m is an integer greater than 1.]

An acid generator according to the fourth aspect of the present invention is characterized by containing a compound as described in the third aspect above. [Effect of the invention]

According to the present invention, a resist composition that achieves high sensitivity when forming a resist pattern and improves lithography properties such as CDU and fine resolution, a resist pattern forming method using the resist composition, and a compound useful as an acid generator component used in the resist composition can be provided.

[Type of implementation of the invention]

In this specification and the scope of this patent application, the so-called "aliphatic" is defined as a relative concept of aromatic, and refers to compounds without aromatic groups. "Alkyl" includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to alkyl groups in alkoxy groups. "Alkylene" includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified. "Halogen atom" includes fluorine atom, chlorine atom, bromine atom and iodine atom. The so-called "constituent unit" refers to the monomer unit (monomer unit) constituting a high molecular compound (resin, polymer, copolymer). When it is described as "may have a substituent", it includes both the case where the hydrogen atom (-H) is substituted by a monovalent group and the case where the methylene group (-CH ₂ -) is substituted by a divalent group. "Exposure" includes the concept of overall irradiation with radiation.

"Acid-decomposable group" is a group having acid-decomposability, and the acid-decomposability is that at least a part of the bonds in the structure of the acid-decomposable group can be untied by the action of an acid. Examples of acid-decomposable groups whose polarity is increased by the action of an acid include groups that generate polar groups by decomposition by the action of an acid. Examples of polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfonic acid groups (-SO ₃ H). More specifically, examples of acid-decomposable groups include groups in which the aforementioned polar groups are protected by acid-decomposable groups (e.g., groups in which the hydrogen atom of a polar group containing OH is protected by an acid-decomposable group).

The so-called "acid-dissociable group" means (i) an acid-dissociable group that can cleave the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid, or (ii) a group that can cleave the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by further generating a decarbonation reaction after a portion of the bonds are cleaved by the action of an acid. The acid-dissociable group constituting the acid-dissociable group must be a group with a lower polarity than the polar group generated by the dissociation of the acid-dissociable group, so that when the acid-dissociable group is dissociated by the action of an acid, a polar group with a higher polarity than the acid-dissociable group is generated to increase the polarity. As a result, the polarity of the (A1) component as a whole increases. The increase in polarity relatively changes the solubility of the developer, and the solubility increases in the case of an alkaline developer, and decreases in the case of an organic developer.

The so-called "base component" refers to an organic compound that has the ability to form a film. Organic compounds used as base components can be roughly divided into non-polymers and polymers. As non-polymers, those with a molecular weight of 500 or more and less than 4000 (hereinafter referred to as "low molecular weight compounds") are generally used. In the case of "resin", "high molecular weight compound" or "polymer" below, it means a polymer with a molecular weight of 1000 or more. As the molecular weight of the polymer, the weight average molecular weight converted to polystyrene obtained by GPC (gel permeation chromatography) is used.

The so-called "derived constituent unit" means multiple bonds between carbon atoms, for example, it means a constituent unit formed by cleaving an ethylenic double bond. The hydrogen atom bonded to the α-carbon atom in "acrylate" may be substituted by a substituent. The substituent (R ^αx ) replacing the hydrogen atom bonded to the α-carbon atom is an atom or group other than a hydrogen atom. In addition, it also includes itaconate diesters in which the substituent (R ^αx ) is substituted by a substituent containing an ester bond, or α-hydroxy acrylates in which the substituent (R ^αx ) is substituted by a hydroxyalkyl group or a group in which the hydroxy group is modified. Furthermore, unless otherwise specified, the α-carbon atom of the acrylate refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylate in which the hydrogen atom bonded to the α-carbon atom is substituted with a substituent may be referred to as an α-substituted acrylate.

The term "derivative" refers to a compound in which the α-position hydrogen atom of the target compound is replaced by another substituent such as an alkyl group or a halogenated alkyl group, and the concept of such derivatives. Examples of such derivatives include compounds in which the α-position hydrogen atom may be replaced by a substituent, compounds in which the hydroxyl hydrogen atom of the target compound may be replaced by an organic group, compounds in which the α-position hydrogen atom may be replaced by a substituent, compounds in which a substituent other than a hydroxyl group is bonded, and the like. Furthermore, unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. Examples of the substituent for the α-position hydrogen atom of substituted hydroxystyrene include the same as R ^αx .

In the description and the scope of the patent application of this case, the structure shown by the chemical formula has asymmetric carbon, and enantiomers or diastereomers may exist. In this case, one of the chemical formulas represents these isomers. These isomers can be used alone or as a mixture.

(Resistant composition) The resist composition of this embodiment generates acid by exposure, and changes the solubility of the developer by the action of the acid. The resist composition contains a base component (A) (hereinafter also referred to as "(A) component") that changes the solubility of the developer by the action of the acid and an acid generator component (B) (hereinafter also referred to as "(B) component") that generates acid by exposure. The aforementioned (B) component contains a compound (B0) represented by the general formula (b0).

When a resist film is formed using the resist composition of the present embodiment and the resist film is selectively exposed, an acid is generated from the component (B) in the exposed portion of the resist film. Due to the action of the acid, the solubility of the component (A) in the developer changes. Meanwhile, in the unexposed portion of the resist film, the solubility of the component (A) in the developer does not change. Therefore, a difference occurs in the solubility in the developer between the exposed portion and the unexposed portion of the resist film. Therefore, when the resist film is developed, when the resist composition is positive, the exposed portion of the resist film is dissolved and removed to form a positive resist pattern, and when the resist composition is negative, the unexposed portion of the resist film is dissolved and removed to form a negative resist pattern.

The resist composition of the present embodiment can be a positive resist composition or a negative resist composition. Furthermore, the resist composition of the present embodiment can be used in an alkali development process using an alkali developer in the development process when forming a resist pattern, and can also be used in a solvent development process using a developer containing an organic solvent (organic developer) in the development process.

<Base component (A)> In the resist composition of this embodiment, the (A) component contains a resin component (A1) (hereinafter also referred to as "(A1) component") whose solubility in the developer changes due to the action of an acid. By using the (A1) component, the polarity of the base component changes before and after exposure, and good development contrast can be obtained not only in an alkaline development process but also in a solvent development process. As the (A) component, other high molecular weight compounds and/or low molecular weight compounds may be used in combination with the (A1) component.

In the inhibitor composition of this embodiment, the component (A) may be used alone or in combination of two or more.

･Regarding the component (A1), The component (A1) is a resin component whose solubility in the developer changes due to the action of an acid. As the component (A1), it is preferred to have a constituent unit (a1) containing an acid-degradable group whose polarity increases due to the action of an acid. In addition to the constituent unit (a1), the component (A1) may also have other constituent units as necessary.

≪Constituent unit (a1)≫ Constituent unit (a1) is a constituent unit containing an acid-degradable group whose polarity is increased by the action of an acid.

As the acid-dissociable group, those proposed as the acid-dissociable group of the base resin for the chemically amplified resistor composition can be cited so far. Specifically, the acid-dissociable group proposed as the base resin for the chemically amplified resistor composition includes the "acetal type acid-dissociable group", "third-level alkyl ester type acid-dissociable group", "third-level alkoxycarbonyl acid-dissociable group", and "second-level alkoxycarbonyl acid-dissociable group" described below.

Acetal type acid-dissociable group: Among the aforementioned polar groups, the acid-dissociable group that protects the carboxyl group or the hydroxyl group may be, for example, an acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal type acid-dissociable group").

[In the formula, Ra' ¹ and Ra' ² are hydrogen atoms or alkyl groups. Ra' ³ is a alkyl group, and Ra' ³ can be bonded with either Ra' ¹ or Ra' ² to form a ring.]

In formula (a1-r-1), at least one of ^Ra'1 and ^Ra'2 is preferably a hydrogen atom, and both are more preferably hydrogen atoms. When ^Ra'1 or ^Ra'2 is an alkyl group, the alkyl group may be the same as the alkyl group listed as a substituent that can be bonded to the α-carbon atom in the description of the α-substituted acrylate, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, a straight chain or branched chain alkyl group may be preferably cited. 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. may be cited, and a methyl group or an ethyl group may be preferably cited, and a methyl group may be particularly preferred.

In formula (a1-r-1), as the alkyl group of Ra' ³ , a linear or branched alkyl group or a cyclic alkyl group can be cited. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and more preferably 1 or 2 carbon atoms. Specifically, methyl, ethyl, n-propyl, n-butyl, n-pentyl and the like can be cited. Among these, methyl, ethyl or n-butyl are also preferred, and methyl or ethyl is more preferred.

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

When ^Ra'3 is a cyclic alkyl group, the alkyl group may be an aliphatic alkyl group or an aromatic alkyl group, and may be a polycyclic group or a monocyclic group. The aliphatic alkyl group as a monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocyclic alkane. The monocyclic alkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group as the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isoborneol, tricyclodecane, tetracyclododecane and the like.

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

The cyclic alkyl group in ^Ra'3 may have a substituent. Examples of the substituent include ^-RP1 , ^-RP2 - ^ORP1 , -RP2-CO-RP1, -RP2 ^- CO- ^ORP1 , -RP2 ^- O-CO- ^RP1 , -RP2 ^{- OH} , ^-RP2 -CN or ^{-RP2 -} COOH (hereinafter, these substituents are collectively referred to as " ^Rax5 "). Among them, ^RP1 is a monovalent chain saturated alkyl group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated alkyl group having 3 to 20 carbon atoms or a monovalent aromatic alkyl group having 6 to 30 carbon atoms. Furthermore, ^RP2 is a single bond, a divalent chain saturated alkyl group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated alkyl group having 3 to 20 carbon atoms, or a divalent aromatic alkyl group having 6 to 30 carbon atoms. However, a part or all of the hydrogen atoms possessed by the chain saturated alkyl group, aliphatic cyclic saturated alkyl group and aromatic alkyl group of ^RP1 and ^RP2 may be substituted by fluorine atoms. The above-mentioned aliphatic cyclic alkyl group may have one or more of the above-mentioned substituents alone, or may have more than one of the above-mentioned substituents. Examples of the monovalent chain saturated alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl and the like. Examples of the monovalent aliphatic cyclic saturated alkyl group having 3 to 20 carbon atoms include monocyclic aliphatic saturated alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl and cyclododecyl; and polycyclic aliphatic saturated alkyl groups such as bicyclic [2.2.2]octyl, tricyclo [5.2.1.02,6]decyl, tricyclo [3.3.1.13,7]decyl, tetracyclo [6.2.1.13,6.02,7]dodecyl and adamantyl. 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, and phenanthrene.

When ^Ra'3 is bonded to either ^Ra'1 or ^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 tetrahydropyranyl and tetrahydrofuranyl.

Third-level alkyl ester type acid-dissociable group: Among the above polar groups, as an acid-dissociable group for protecting the carboxyl group, for example, an acid-dissociable group represented by the following general formula (a1-r-2) can be cited. In addition, among the acid-dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups are sometimes referred to as "third-level alkyl ester type acid-dissociable groups" below.

[In the formula, Ra' ⁴ to Ra' ⁶ are each a alkyl group, and Ra' ⁵ and Ra' ⁶ are bonded to each other to form a ring.]

As the alkyl group of Ra' ⁴ , there can be mentioned a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic alkyl group. The linear or branched alkyl group, and the cyclic alkyl group (monocyclic aliphatic alkyl group, polycyclic aliphatic alkyl group, aromatic alkyl group) in Ra' ⁴ can be the same as those in Ra' ³ above. The linear or cyclic alkenyl group in Ra' ⁴ is preferably an alkenyl group having 2 to 10 carbon atoms. As the alkyl group of Ra' ⁵ and Ra' ⁶ , there can be mentioned the same as those in Ra' ³ above.

When ^Ra'5 and ^Ra'6 are bonded to form a ring, preferably, there are 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). On the other hand, when ^Ra'4 to ^Ra'6 are not bonded to each other and are independently alkyl groups, preferably, there are groups represented by the following general formula (a1-r2-4).

[In formula (a1-r2-1), Ra' ¹⁰ represents a linear or branched alkyl group having 1 to 12 carbon atoms, a portion of which may be substituted by a halogen atom or a group containing a heteroatom. Ra' ¹¹ represents a group that can form an aliphatic cyclic group together with the carbon atom to which Ra' ¹⁰ is bound. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. A part or all of the hydrogen atoms possessed by the cyclic hydrocarbon group may be substituted. Ra ¹⁰¹ to Ra ¹⁰³ are each independently a hydrogen atom, a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. A part or all of the hydrogen atoms possessed by the chain saturated alkyl group and the aliphatic cyclic saturated alkyl group may be substituted. Two or more of Ra ¹⁰¹ to Ra ¹⁰³ may be bonded to each other to form a ring structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra ¹⁰⁴ is an aromatic alkyl group that may have a substituent. In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain saturated alkyl group having 1 to 10 carbon atoms. A part or all of the hydrogen atoms possessed by the chain saturated alkyl group may be substituted. Ra' ¹⁴ is a alkyl group that may have a substituent. * indicates a bonding position (the same applies below). ]

In the above formula (a1-r2-1), ^Ra'10 is a linear or branched alkyl group having 1 to 12 carbon atoms which may be partially substituted with a halogen atom or a group containing a heteroatom.

As the linear alkyl group in ^Ra'10 , the carbon number is 1 to 12, preferably 1 to 10, and particularly preferably 1 to 5. As the branched alkyl group in ^Ra'10 , the same as those mentioned above for ^Ra'3 can be cited.

A part of the alkyl group in Ra' ¹⁰ may be substituted by a halogen atom or a group containing a heteroatom. For example, a part of the hydrogen atoms constituting the alkyl group may be substituted by a halogen atom or a group containing a heteroatom. In addition, a part of the carbon atoms (methylene group, etc.) constituting the alkyl group may be substituted by a group containing a heteroatom. As the heteroatom here, an oxygen atom, a sulfur atom, and a nitrogen atom may be cited. As the group containing a heteroatom, (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, etc. may be cited.

In formula (a1-r2-1), Ra' ¹¹ (the aliphatic cyclic group formed by Ra' ¹⁰ and the carbon atom to which it is bonded) is preferably a group listed as the aliphatic hydrocarbon group (alicyclic hydrocarbon group) of the monocyclic group or polycyclic group of Ra' ³ in formula (a1-r-1). Among them, the monocyclic alicyclic hydrocarbon group is also preferred, and specifically, cyclopentyl and cyclohexyl are preferred.

In the formula (a1-r2-2), as the cyclic hydrocarbon group formed by Xa and Ya together, there can be mentioned the group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in Ra' ³ in the aforementioned formula (a1-r-1). The cyclic hydrocarbon group formed by Xa and Ya together may have a substituent. As the substituent, there can be mentioned the same substituents that the cyclic hydrocarbon group in the aforementioned Ra' ³ may have. In the formula (a1-r2-2), in Ra ¹⁰¹ to Ra ¹⁰³ , as the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, there can be mentioned, 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. In Ra ¹⁰¹ to Ra ¹⁰³ , examples of the monovalent aliphatic cyclic saturated alkyl group having 3 to 20 carbon atoms include monocyclic aliphatic saturated alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl and cyclododecyl; and polycyclic aliphatic saturated alkyl groups such as bicyclic [2.2.2]octyl, tricyclo [5.2.1.02,6]decyl, tricyclo [3.3.1.13,7]decyl, tetracyclo [6.2.1.13,6.02,7]dodecyl and adamantyl. Among them, Ra ¹⁰¹ to Ra ¹⁰³ are preferably a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms from the viewpoint of ease of synthesis, and among them, a hydrogen atom, a methyl group, and an ethyl group are more preferred, and a hydrogen atom is particularly preferred.

Examples of the substituent possessed by the chain saturated hydrocarbon group or aliphatic cyclic saturated hydrocarbon group represented by Ra ¹⁰¹ to Ra ¹⁰³ include the same substituents as those for Ra ^x5 above.

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

In the formula (a1-r2-3), the aliphatic cyclic group formed by Xaa and Yaa is preferably an aliphatic hydrocarbon group of a monocyclic group or a polycyclic group of Ra' ³ in the formula (a1-r-1). In the formula (a1-r2-3), the aromatic hydrocarbon group in Ra ¹⁰⁴ may be a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra ¹⁰⁴ represents 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, even more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene or naphthalene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.

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

In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain saturated alkyl group having 1 to 10 carbon atoms. In Ra' ¹² and Ra' ¹³ , the monovalent chain saturated alkyl group having 1 to 10 carbon atoms includes the same as the monovalent chain saturated alkyl group having 1 to 10 carbon atoms in Ra ¹⁰¹ to Ra ^103. A part or all of the hydrogen atoms possessed by the chain saturated alkyl group may be substituted. In Ra' ¹² and Ra' ¹³ , an alkyl group having 1 to 5 carbon atoms is preferred, an alkyl group having 1 to 5 carbon atoms is more preferred, a methyl group and an ethyl group are more preferred, and a methyl group is particularly preferred. When the chain saturated alkyl group represented by ^Ra'12 and ^Ra'13 is substituted, examples of the substituent include the same groups as those exemplified for ^Rax5 .

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

The linear alkyl group in Ra' ¹⁴ preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and more preferably 1 or 2 carbon atoms. Specific examples include methyl, ethyl, n-propyl, n-butyl, n-pentyl, etc. Among them, methyl, ethyl or n-butyl is preferred, and methyl or ethyl is more preferred.

The branched chain alkyl group in Ra' ¹⁴ preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, 2,2-dimethylbutyl, etc., with isopropyl being preferred.

When Ra' ¹⁴ is a cyclic alkyl group, the alkyl group may be an aliphatic alkyl group, an aromatic alkyl group, a polycyclic group, or a monocyclic group. The aliphatic alkyl group as a monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocyclic alkane. The monocyclic alkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group as the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isoborneol, tricyclodecane, tetracyclododecane and the like.

As the aromatic hydrocarbon group in Ra' ¹⁴ , the same ones as the aromatic hydrocarbon group in Ra ¹⁰⁴ can be cited. 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, 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. As the substituent that Ra' ¹⁴ may have, the same ones as the substituent that Ra ¹⁰⁴ may have can be cited.

When Ra' ¹⁴ in formula (a1-r2-4) is a naphthyl group, the bonding position to the third carbon atom in the aforementioned formula (a1-r2-4) may be either the 1st position or the 2nd position of the naphthyl group. When Ra' ¹⁴ in formula (a1-r2-4) is an anthracene group, the bonding position to the third carbon atom in the aforementioned formula (a1-r2-4) may be either the 1st position, the 2nd position or the 9th position of the anthracene group.

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

Specific examples of the group represented by the above formula (a1-r2-2) include the following.

Specific examples of the group represented by the above formula (a1-r2-3) include the following.

Specific examples of the group represented by the above formula (a1-r2-4) include the following.

Third-level alkoxycarbonyl acid-dissociable group: As the acid-dissociable group for protecting the hydroxyl group in the aforementioned polar group, for example, there can be cited the acid-dissociable group represented by the following general formula (a1-r-3) (hereinafter sometimes referred to as "third-level alkoxycarbonyl acid-dissociable group").

[In the formula, Ra' ⁷ to Ra' ⁹ are each an alkyl group.]

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

Secondary alkyl ester type acid-dissociable group: Among the above polar groups, the acid-dissociable group for protecting the carboxyl group may be, for example, an acid-dissociable group represented by the following general formula (a1-r-4).

[In the formula, ^Ra'10 is a alkyl group. ^Ra'11a and ^Ra'11b are each independently a hydrogen atom, a halogen atom or an alkyl group. ^Ra'12 is a hydrogen atom or a alkyl group. ^Ra'10 and ^Ra'11a or ^Ra'11b may bond to each other to form a ring. ^Ra'11a or ^Ra'11b and ^Ra'12 may bond to each other to form a ring.]

In the formula, as the alkyl group in ^Ra'10 and ^Ra'12 , the same as the aforementioned ^Ra'3 can be cited. In the formula, as the alkyl group in ^Ra'11a and ^Ra'11b , the same as the aforementioned alkyl group in ^Ra'1 can be cited. In the formula, the alkyl group in ^Ra'10 and ^Ra'12 , and the alkyl group in ^Ra'11a and ^Ra'11b may have a substituent. As the substituent, for example, the aforementioned ^Rax5 can be cited.

^Ra'10 and ^Ra'11a or ^Ra'11b may bond to each other to form a ring. The ring may be polycyclic, monocyclic, alicyclic, or aromatic. The alicyclic and aromatic rings may contain heteroatoms.

As the ring formed by the mutual bonding of ^Ra'10 and ^Ra'11a or ^Ra'11b , among the above, monocyclic olefins, cyclic olefins in which part of the carbon atoms are substituted by heteroatoms (oxygen atoms, sulfur atoms, etc.), and monocyclic dienes are preferred. Cycloolefins having 3 to 6 carbon atoms are preferred, and cyclopentene or cyclohexene is preferred.

The ring formed by the mutual bonding of ^Ra'10 and ^Ra'11a or ^Ra'11b may be a condensed ring. Specific examples of the condensed ring include indane and the like.

The ring formed by the mutual bonding of ^Ra'10 and ^Ra'11a or ^Ra'11b may have a substituent. Examples of the substituent include the above-mentioned Ra ^x5 .

Ra' ^11a or Ra' ^11b and Ra' ¹² may bond to each other to form a ring, and examples of the ring include the same ring as the ring formed by bonding Ra' ¹⁰ and Ra' ^11a or Ra' ^11b .

Specific examples of the group represented by the above formula (a1-r-4) include the following.

Examples of the constituent unit (a1) include a constituent unit derived from an acrylic ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, a constituent unit derived from an acrylamide, a constituent unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a portion of the hydrogen atoms in the hydroxyl group are protected by a substituent containing the aforementioned acid-decomposable group, a constituent unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative in which at least a portion of the hydrogen atoms in -C(=O)-OH are protected by a substituent containing the aforementioned acid-decomposable group, and the like.

As the constituent unit (a1), among the above, a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom may be substituted by a substituent is also preferred. As a preferred specific example of the constituent unit (a1), the constituent units represented by the following general formula (a1-1), (a1-2) or (a1-3) can be cited.

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ^{Va 1} is a divalent hydrocarbon group which may have an ether bond. _{n a1} is an integer from 0 to 2. Ra ¹ is an acid-dissociable group represented by the above-mentioned general formula (a1-r-1), (a1-r-2) or (a1-r-4). ^{Wa 1} is a n _a2 +1-valent hydrocarbon group, n _a2 is an integer from 1 to 3, and Ra ² is an acid-dissociable group represented by the above-mentioned general formula (a1-r-1) or (a1-r-3). Ya ⁰⁰¹ is a single bond or a divalent linking group. ^{Ya 01} is a single bond or a divalent linking group. ^{Rax 01} is an acid-dissociable group represented by the above-mentioned general formula (a1-r-1), (a1-r-2) or (a1-r-4). Rz ⁰¹ is an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxyl group or an alkoxy group. q is an integer from 0 to 3. n is an integer greater than 0. However, n ≤ q × 2 + 4.]

In the above formula (a1-1), 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 specific examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which a part or all of the hydrogen atoms of the above alkyl group having 1 to 5 carbon atoms are substituted by halogen atoms. As the halogen atom, a fluorine atom is particularly preferred. 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 preferred, and a hydrogen atom or a methyl group is the best in terms of ease of industrial availability.

In the aforementioned formula (a1-1), the divalent hydrocarbon group in ^Va1 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, but a saturated hydrocarbon group is generally preferred. More specifically, the aliphatic hydrocarbon group may be a linear or branched chain aliphatic hydrocarbon group or an aliphatic hydrocarbon group containing a ring in its structure.

The aforementioned linear aliphatic alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic alkyl group, a linear alkylene group is preferred, and specific examples thereof include methylene [-CH ₂ -], ethylene [-(CH ₂ ) ₂ -], trimethylene [-(CH ₂ ) ₃ -], tetramethylene [-(CH ₂ ) ₄ -], and pentamethylene [-(CH ₂ ) ₅ -]. The aforementioned branched aliphatic alkyl group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched chain aliphatic hydrocarbon group is preferably a branched chain alkylene group, and specific examples thereof include -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH 3 )-, -C(CH 3 )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and the like alkylmethylene groups; -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH 3 )-, -C(CH ₃ ) ₂ CH 2 -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ CH ₃ ) 2 - and the like alkylethylene groups; -CH(CH 3 )CH ₂ -, -CH(CH ₃ )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH ₂ CH ₃ )CH 2 -, -C(CH 2 CH 3 ) ₂ -CH ₂ - and the like alkylethylene groups; -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -, alkyl trimethylene, -CH(CH ₃ )CH ₂ CH _{2 -} , -CH ₂ CH(CH ₃ )CH _{2 CH 2 -, etc.; alkyl alkylene groups such as -CH(CH 3 )CH 2 CH 2} -, etc. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

As the aliphatic hydrocarbon group containing a ring in the above structure, there can be cited 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 straight chain or branched chain aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is separated in the middle of a straight chain or branched chain aliphatic hydrocarbon group, etc. As the above-mentioned straight chain or branched chain aliphatic hydrocarbon group, there can be cited the same ones as the above-mentioned straight chain aliphatic hydrocarbon group or the above-mentioned branched chain aliphatic hydrocarbon group. The above-mentioned alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The aforementioned alicyclic hydrocarbon group may be polycyclic or monocyclic. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocyclic alkane is preferred. As the monocyclic alkane, a group having 3 to 6 carbon atoms is preferred, and specific examples thereof include cyclopentane and cyclohexane. As a polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isoborneol, tricyclodecane, tetracyclododecane, and the like.

The aromatic hydrocarbon group as the divalent hydrocarbon group in ^Va1 is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, more preferably 5 to 20, particularly preferably 6 to 15, and most 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 possessed by 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 aforementioned aromatic hydrocarbon rings are substituted by heteroatoms. Examples of the heteroatoms in the aromatic heterocyclic ring include oxygen atoms, sulfur atoms, nitrogen atoms, and the like. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aforementioned aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aforementioned aromatic hydrocarbon ring (aryl group) in which one hydrogen atom is substituted by an alkylene group (for example, a group obtained by further removing one hydrogen atom from an aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The number of carbon atoms in the aforementioned alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In the aforementioned formula (a1-1), ^Ra1 is an acid-lysable group represented by the aforementioned formula (a1-r-1), (a1-r-2) or (a1-r-4).

In the aforementioned formula (a1-2), the _na2 +1 valence alkyl group in ^Wa1 may be an aliphatic alkyl group or an aromatic alkyl group. The aliphatic alkyl group means a alkyl group which does not have aromaticity and may be saturated or unsaturated, but saturated alkyl groups are generally preferred. Examples of the aforementioned aliphatic alkyl group include a linear or branched aliphatic alkyl group, an aliphatic alkyl group containing a ring in its structure, or a combination of a linear or branched aliphatic alkyl group and an aliphatic alkyl group containing a ring in its structure. The aforementioned _na2 +1 valence is preferably 2 to 4, and more preferably 2 or 3.

In the aforementioned formula (a1-2), Ra ² is an acid-liquidable group represented by the aforementioned general formula (a1-r-1) or (a1-r-3).

In the above formula (a1-3), the divalent linking group in ^Ya001 is not particularly limited, but preferably includes a divalent alkyl group which may have a substituent and a divalent linking group containing a heteroatom. ^Ya001 is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic alkylene group, or a combination thereof or a single bond. The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. Among these, as Ya ⁰⁰¹ , a combination of an ester bond [—C(═O)—O—, —OC(═O)—] and a linear alkylene group, or a single bond is preferred, and a single bond is more preferred.

In the above formula (a1-3), the divalent linking group in Ya ⁰¹ is not particularly limited, and preferably includes a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like. Among the above, Ya ⁰¹ is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof or a single bond. Among these, Ya ⁰¹ is preferably a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, or a single bond, and more preferably a single bond.

In the aforementioned formula (a1-3), Rax ⁰¹ is preferably an acid-lysable group represented by the aforementioned general formula (a1-r-2) or (a1-r-4). Among them, the acid-lysable group represented by the general formula (a1-r-2) is also preferred, and the group represented by the general formula (a1-r2-1) is even more preferred.

In the aforementioned formula (a1-3), the alkyl group, halogenated alkyl group and alkoxy group in Rz ⁰¹ preferably have 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The aforementioned alkyl group, halogenated alkyl group and alkoxy group may be in the form of a straight chain or a branched chain. The halogen atom in Rz ⁰¹ is preferably an iodine atom or a bromine atom. The halogen atom of the halogenated alkyl group in Rz ⁰¹ is preferably a fluorine atom, an iodine atom or a bromine atom, and preferably a fluorine atom. Rz ⁰¹ is preferably an alkoxy group or a hydroxyl group, and preferably a hydroxyl group.

In the aforementioned formula (a1-3), q is an integer of 0 to 3. When q is 0, a benzene structure is obtained, when q is 1, a naphthalene structure is obtained, when q is 2, an anthracene structure is obtained, and when q is 3, a tetracene structure is obtained. In the aforementioned formula (a1-3), n is an integer greater than or equal to 0, preferably an integer of 0 to 5, more preferably an integer of 0 to 3, and more preferably 1 or 2. When n is an integer greater than or equal to 2, two or more Rz ⁰¹ may be the same or different from each other. In the aforementioned formula (a1-3), n≦q×2+4. For example, when q is 1 in the case of a naphthalene structure, all six hydrogen atoms of the naphthalene may be substituted by Rz ⁰¹ . In the naphthalene, the substitution positions of Ya ⁰⁰¹ , -Ya ⁰¹ -C(=O)-O-Ra ⁰¹ group and Rz ⁰¹ are not particularly limited.

Specific examples of the constituent unit (a1) are shown below. In the following formulae, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

In the following formulae, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group. R z each independently represents a hydrogen atom, an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxyl group or an alkoxy group.

The constituent unit (a1) of the component (A1) may be one or more. As the constituent unit (a1), the constituent unit represented by the above formula (a1-1) or the constituent unit represented by the above formula (a1-3) is preferred because it can easily improve the characteristics (sensitivity, shape, etc.) during photolithography by electron beam or EUV. Among them, from the viewpoint of preferably improving the reactivity for EB or EUV, the acid-dissociable groups (Ra ¹ , Rax ⁰¹ ) are preferably acid-dissociable groups represented by the above general formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4), and those selected from cyclic groups are particularly preferred.

The ratio of the constituent unit (a1) in the component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, more preferably 30 to 70 mol%, and particularly preferably 40 to 70 mol% relative to the total of all constituent units constituting the component (A1) (100 mol%). By setting the ratio of the constituent unit (a1) to above the lower limit of the aforementioned preferred range, the photolithography characteristics such as sensitivity, in-plane uniformity of pattern size (CDU), and fine resolution are improved. On the other hand, if it is below the upper limit of the aforementioned preferred range, a balance with other constituent units can be achieved, and various photolithography characteristics become good.

≪Other constituent units≫ Component (A1) may have other constituent units as necessary in addition to the above-mentioned constituent unit (a1). As other constituent units, for example, there can be cited constituent units represented by the following general formula (a10-1), constituent units (a2) having a cyclic group containing lactone, constituent units derived from compounds represented by the following general formula (a8-1), etc.

Constituent unit (a10): Constituent unit (a10) is a constituent unit represented by the following general formula (a10-1).

[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. ^Yax1 is a single bond or a divalent linking group. ^Wax1 is an aromatic hydrocarbon group which may have a substituent. _Nax1 is an integer greater than or equal to 1.]

In the aforementioned formula (a10-1), R is the same as R in the aforementioned general formula (a1-1). 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 preferred, and a hydrogen atom or a methyl group is particularly preferred in view of ease of industrial availability.

In the above formula (a10-1), ^Yax1 is a single bond or a divalent linking group. In the above chemical formula, the divalent linking group in ^Yax1 is not particularly limited, and preferably includes a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like.

･Divalent hydrocarbon groups that may have a substituent: Divalent hydrocarbon groups that may have a substituent may be aliphatic hydrocarbon groups or aromatic hydrocarbon groups.

･･Aliphatic alkyl Aliphatic alkyl refers to a alkyl group that does not have aromaticity. The aliphatic alkyl group may be saturated or unsaturated, and saturated alkyl groups are generally preferred. Examples of the aliphatic alkyl group include a linear or branched aliphatic alkyl group, or an aliphatic alkyl group containing a ring in the structure.

･･･Linear or branched aliphatic alkyl group The linear aliphatic alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. The linear aliphatic alkyl group is preferably a linear alkylene group, and specific examples thereof include methylene [-CH ₂ -], ethylene [-(CH ₂ ) ₂ -], trimethylene [-(CH ₂ ) ₃ -], tetramethylene [-(CH ₂ ) ₄ -], and pentamethylene [-(CH ₂ ) ₅ -]. The branched aliphatic alkyl group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched chain aliphatic hydrocarbon group is preferably a branched chain alkylene group, and specific examples thereof include -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH 3 )-, -C(CH 3 )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and the like alkylmethylene groups; -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH 3 )-, -C(CH ₃ ) ₂ CH 2 -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ CH ₃ ) 2 - and the like alkylethylene groups; -CH(CH 3 )CH ₂ -, -CH(CH ₃ )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH ₂ CH ₃ )CH 2 -, -C(CH 2 CH 3 ) ₂ -CH ₂ - and the like alkylethylene groups; -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -, alkyltrimethylene, -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, alkyltetramethylene, _etc. , alkylalkylene, etc. The alkyl in the alkylalkylene is preferably a linear alkyl having 1 to 5 carbon atoms.

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, and a carbonyl group.

･･･Aliphatic alkyl group containing a ring in the structure As the aliphatic alkyl group containing a ring in the structure, there can be mentioned a cyclic aliphatic alkyl group (a group obtained by removing two hydrogen atoms from an aliphatic alkyl ring) which may also contain a substituent containing a heteroatom in the ring structure, a group in which the aforementioned cyclic aliphatic alkyl group is bonded to the end of a linear or branched aliphatic alkyl group, a group in which the aforementioned cyclic aliphatic alkyl group is separated in the middle of a linear or branched aliphatic alkyl group, etc. As the aforementioned linear or branched aliphatic alkyl group, the same as mentioned above can be mentioned. The cyclic aliphatic alkyl 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 a monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocyclic alkane is preferred. As the monocyclic alkane, a group having 3 to 6 carbon atoms is preferred, and specific examples thereof include cyclopentane and cyclohexane. As a polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isoborneol, tricyclodecane, tetracyclododecane, and the like.

The cyclic aliphatic alkyl 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. 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 more preferred. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, and 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 more preferred. As the halogen atom as the substituent, a fluorine atom is preferred. As the halogenated alkyl group as the substituent, examples include a group in which a part or all of the hydrogen atoms of the alkyl group are substituted by the halogen atom. A portion of the carbon atoms constituting the ring structure of the cyclic aliphatic hydrocarbon group may be substituted by a substituent containing a heteroatom. Preferred substituents containing a heteroatom are -O-, -C(=O)-O-, -S-, -S(=O) ₂ -, and -S(=O) ₂ -O-.

･･Aromatic alkyl The aromatic alkyl group is a alkyl group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugate 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, 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. As the aromatic ring, there are specifically mentioned aromatic alkyl rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the aforementioned aromatic alkyl rings are substituted by heteroatoms, and the like. As the heteroatom in the aromatic heterocyclic ring, oxygen atom, sulfur atom, nitrogen atom, etc. can be cited. As the aromatic heterocyclic ring, specifically, pyridine ring, thiophene ring, etc. can be cited. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aforementioned aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound having two or more aromatic rings (e.g., biphenyl group, fluorene, etc.); a group obtained by removing one hydrogen atom from the aforementioned aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) in which one hydrogen atom is substituted by an alkylene group (e.g., a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The alkylene group bonded to the aforementioned aryl or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

In the aforementioned aromatic alkyl group, the hydrogen atom possessed by the aromatic alkyl group may also be substituted by a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic alkyl group may be substituted by a substituent. Examples of the substituent include alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxyl groups, etc. As the aforementioned substituent, the alkyl group having 1 to 5 carbon atoms is preferred, and methyl, ethyl, propyl, n-butyl, and tert-butyl are preferred. As the aforementioned substituent, the alkoxy group, halogen atom, and halogenated alkyl group may be exemplified as the substituent for replacing the hydrogen atom possessed by the aforementioned cyclic aliphatic alkyl group.

･Divalent linking group containing a heteroatom: As the divalent linking group containing a heteroatom, there can be mentioned -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted by a substituent such as an alkyl group or an acyl group), -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, general formula -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-OY ²¹ -, -[Y ²¹ -C(=O)-O] _m" -Y ²² -, -Y ²¹ -OC(=O)-Y ²² - or -Y ²¹ -S(=O) ₂ -OY ²² - [wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer of 1 to 3.], etc. When the divalent linking group containing the aforementioned heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)-, the H may be substituted by 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. In the general formula -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-OY ²¹ -, -[Y ²¹ -C(=O)-O] _m" -Y ²² -, -Y ²¹ -OC(=O)-Y ²² - or -Y ²¹ -S(=O) ₂ -OY ²² -, 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 as those mentioned above. Y ²¹ is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, 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 straight-chain or branched-chain aliphatic alkyl group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a straight-chain alkyl group having 1 to 5 carbon atoms, more preferably a straight-chain 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 1 to 3, preferably 1 or 2, and particularly preferably 1. In other words, 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)-OY ²² - is particularly preferred. Among them, the group represented by the formula -(CH ₂ ) _{a '} -C(=O)-O-(CH ₂ ) _{b '} - is also 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, 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, more preferably 1 or 2, and most preferably 1.

As Ya ^x1 , a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group or a combination thereof is preferred, and a single bond, an ester bond [-C(=O)-O-, -OC(=O)-] is more preferred.

In the aforementioned formula (a10-1), ^Wax1 is an aromatic hydrocarbon group which may have a substituent. As the aromatic hydrocarbon group in ^Wax1 , there can be mentioned a group obtained by removing ( _nax1 +1) hydrogen atoms from an aromatic ring which may have a substituent. Such aromatic rings are not particularly limited as long as they are cyclic conjugated systems having 4n+2 π electrons. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, 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 a part of the carbon atoms constituting the aforementioned aromatic hydrocarbon rings are substituted by heteroatoms. As the hetero atom in the aromatic heterocyclic ring, an oxygen atom, a sulfur atom, a nitrogen atom, etc. can be cited. As the aromatic heterocyclic ring, specifically, a pyridine ring, a thiophene ring, etc. can be cited. Furthermore, as the aromatic alkyl group in Wa ^x1 , a group obtained by removing (n _ax1 +1) hydrogen atoms from an aromatic compound containing an aromatic ring which may have two or more substituents (e.g., biphenyl group, fluorene, etc.) can be cited. Among the above, as Wa ^x1 , a group obtained by removing (n _ax1 +1) hydrogen atoms from benzene, naphthalene, anthracene, or biphenyl group is preferred, a group obtained by removing (n _ax1 +1) hydrogen atoms from benzene or naphthalene is more preferred, and a group obtained by removing (n _ax1 +1) hydrogen atoms from benzene is even more preferred.

The aromatic hydrocarbon group in Wa ^x1 may or may not have a substituent. Examples of the aforementioned substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and the like. Examples of the aforementioned substituent include the same ones as those listed as the substituent for the cyclic aliphatic hydrocarbon group in Ya ^x1 . The aforementioned 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, more preferably an ethyl group or a methyl group, and particularly preferably a methyl group. The aromatic hydrocarbon group in Wa ^x1 preferably has no substituent.

In the above formula (a10-1), n _ax1 is an integer greater than or equal to 1, preferably an integer from 1 to 10, more preferably an integer from 1 to 5, more preferably 1, 2 or 3, and particularly preferably 1 or 2.

Specific examples of the constituent unit (a10) represented by the above formula (a10-1) are shown below. In the following formulae, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The constituent unit (a10) of the component (A1) may be one or more. The component (A1) may or may not have the constituent unit (a10), but it is preferred to have the constituent unit (a10). When the component (A1) has the constituent unit (a10), the ratio of the constituent unit (a10) in the component (A1) is preferably 20 to 80 mol%, more preferably 25 to 70 mol%, more preferably 30 to 60 mol%, and particularly preferably 40 to 60 mol% relative to the total of all constituent units constituting the component (A1) (100 mol%). When the ratio of the constituent unit (a10) is set to a value above the lower limit, it becomes easier to increase the sensitivity. On the other hand, when it is set to a value below the upper limit, it is easier to achieve a balance with other constituent units.

Regarding constituent unit (a2): The component (A1) may have a constituent unit (a2) (but excluding constituent units equivalent to the constituent unit (a1)), and the constituent unit (a2) has a lactone-containing cyclic group. The lactone-containing cyclic group of the constituent unit (a2) is effective in improving the adhesion of the resist film to the substrate when the component (A1) is used to form a resist film. In addition, by having the constituent unit (a2), for example, the acid diffusion length can be appropriately adjusted to improve the adhesion of the resist film to the substrate, and the solubility during development can be appropriately adjusted, so that the photolithography characteristics can be improved.

The so-called "lactone-containing cyclic group" means a cyclic group having a ring (lactone ring) containing -O-C(=O)- in the cyclic skeleton. When the lactone ring is counted as the first ring, it is called a monocyclic group when it is only a lactone ring, and when it has other ring structures, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. As the lactone-containing cyclic group in the constituent unit (a2), any one can be used without particular limitation. Specifically, the groups represented by the following general formulas (a2-r-1) to (a2-r-8) can be cited.

As the constituent unit (a2), a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom can be substituted by a substituent is preferred. The constituent unit (a2) is preferably a constituent unit represented by the following general formula (a2-1).

[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 ²¹ is a single bond or a divalent linking group. La ²¹ represents -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, and R' represents a hydrogen atom or a methyl group. However, when La ²¹ is -O-, Ya ²¹ will not become -CO-. Ra ²¹ is a cyclic group containing a lactone.]

In the above formula (a2-1), R is the same as above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is particularly preferably a hydrogen atom or a methyl group in view of industrial availability.

In the above formula (a2-1), the divalent linking group in ^Ya21 is not particularly limited, and preferably includes a divalent alkyl group which may have a substituent, a divalent linking group containing a heteroatom, etc. As the divalent linking group in ^Ya21 , the same as the divalent linking group in ^Yax1 in the above general formula (a10-1) can be mentioned.

Ya ²¹ is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof.

In the above formula (a2-1), it is preferred that Ya ²¹ is a single bond and La ²¹ is -COO- or -OCO-.

In the above formula (a2-1), Ra ²¹ is a lactone-containing cyclic group. Preferred examples of the lactone-containing cyclic group in Ra ²¹ include groups represented by general formulae (a2-r-1) to (a2-r-8) described below.

The constituent unit (a2) of the component (A1) may be one or more. The component (A1) may or may not have the constituent unit (a2). When the component (A1) has the constituent unit (a2), the ratio of the constituent unit (a2) relative to the total of all constituent units constituting the component (A1) (100 mol%) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%. If the ratio of the constituent unit (a2) is set to be above the preferred lower limit, the effect of containing the constituent unit (a2) can be fully obtained by the above-mentioned effect. If it is below the upper limit, a balance with other constituent units can be achieved, and various lithography characteristics become good.

Regarding constituent unit (a8): Constituent unit (a8) is a constituent unit derived from a compound represented by the following general formula (a8-1).

[ ^W2 is a group containing a polymerizable group. ^Yax2 is a single bond or a ( _nax2 +1)-valent linking group. ^Yax2 and ^W2 can form a condensed ring. ^R1 is a fluorinated alkyl group having 1 to 12 carbon atoms. ^R2 is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. ^R2 and ^Yax2 can form a ring structure by bonding to each other. _Nax2 is an integer of 1 to 3.]

The "polymerizable group" in the group containing a polymerizable group of ^W2 refers to a group in which a compound having a polymerizable group can be polymerized by free radical polymerization, for example, a group containing multiple bonds between carbon atoms such as an ethylenic double bond.

The group containing a polymerizable group may be a group consisting of only a polymerizable group or a group consisting of a polymerizable group and other groups other than the polymerizable group. As other groups other than the polymerizable group, a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, etc. may be cited. As the group containing a polymerizable group, for example, a group represented by the chemical formula: C( ^RX11 )( ^RX12 )=C( ^RX13 ) ^-Yax0- may be preferably cited. In the chemical formula, ^RX11 , ^RX12 and ^RX13 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and ^Yax0 is a single bond or a divalent linking group.

Examples of the condensed ring formed by ^Yax2 and ^W2 include a condensed ring formed by a polymerizable group at ^W2 and ^Yax2 , and a condensed ring formed by a group other than the polymerizable group at W2 ^{and Yax2} . The condensed ring formed by ^Yax2 and ^W2 may have a substituent.

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

In the above examples, the constituent unit (a8) is preferably at least one selected from the group consisting of constituent units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09) and (a8-1-10), and is more preferably at least one selected from the group consisting of constituent units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-09).

The constituent unit (a8) of component (A1) may be one or more. Component (A1) may or may not have constituent unit (a8). The ratio of constituent unit (a8) in component (A1) relative to the total of all constituent units constituting component (A1) (100 mol%) is preferably 0 to 50 mol%, more preferably 0 to 30 mol%.

The component (A1) contained in the inhibitor composition may be used alone or in combination of two or more.

As component (A1), for example, a polymer compound having a repeated structure of constituent units (a1) and constituent units (a10) can be cited. As a preferred component (A1), a polymer compound composed of a repeated structure of a constituent unit (a1) and a constituent unit (a10) can be cited. The proportion of the constituent unit (a1) relative to the total (100 mol%) of all constituent units constituting the component (A1) is preferably 20 to 80 mol%, preferably 25 to 70 mol%, more preferably 30 to 60 mol%, and particularly preferably 40 to 60 mol%. The proportion of the constituent unit (a10) relative to the total (100 mol%) of all constituent units constituting the component (A1) is preferably 20 to 80 mol%, preferably 30 to 75 mol%, more preferably 40 to 70 mol%, and particularly preferably 40 to 60 mol%.

The component (A1) can be produced by dissolving the monomers derived from the constituent units in a polymerization solvent, adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the solvent for polymerization. Alternatively, the component (A1) can be produced by dissolving the monomers derived from the constituent unit (a1) and the monomers of any constituent unit (e.g., constituent unit (a10)) in a polymerization solvent, adding the above-mentioned radical polymerization initiator to the solvent for polymerization, and then subjecting the mixture to a deprotection reaction. Furthermore, during the polymerization, 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. The copolymer into which a part of the hydrogen atoms of the alkyl group is introduced is replaced by fluorine atoms, and is effective in reducing development defects or LER (line edge roughness: unevenness of the line sidewall).

The weight average molecular weight (Mw) of the component (A1) (based on the polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, and is preferably 1,000 to 50,000, more preferably 2,000 to 40,000, more preferably 4,000 to 30,000, and particularly preferably 5,000 to 10,000. When the Mw of the component (A1) is set below the preferred upper limit of the range, it has sufficient solubility in the resist solvent when used as a resist, and when it is set above the preferred lower limit of the range, the etching resistance or the cross-sectional shape of the resist pattern is good. The dispersion degree (Mw/Mn) of the (A1) component is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Mn represents the number average molecular weight.

･Regarding component (A2) In the resist composition of this embodiment, a base component (hereinafter referred to as "component (A2)") which is not equivalent to the aforementioned component (A1) and changes the solubility in the developer by the action of an acid may be used as component (A). Component (A2) is not particularly limited, and any one selected from a plurality of conventionally known base components for chemically amplified resist compositions may be used. Component (A2) may be a single polymer compound or a low molecular weight compound, or may be used in combination of two or more thereof.

The ratio of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, more preferably 75% by mass or more, and may be 100% by mass, relative to the total mass of the component (A). When the ratio is set at 25% by mass or more, it becomes easier to form a resist pattern having excellent lithography characteristics such as high sensitivity or in-plane uniformity of pattern size (CDU) and fine resolution.

In the resist composition of this embodiment, the content of the component (A) can be adjusted according to the thickness of the resist film to be formed.

<Acid generator component (B)> The resist composition of this embodiment may contain, in addition to component (A), an acid generator component (component (B)) that generates acid by exposure. Component (B) contains a compound (B0) represented by the following general formula (b0) (hereinafter also referred to as "component (B0)").

･ Regarding the component (B0) The component (B0) is a compound represented by the following general formula (b0).

[In the formula, ^Rb is an alkali-decomposable group. ^L03 is a divalent linking group. ^Rl0 is a cyclic organic group which may have a substituent. ^L02 is a divalent linking group. I is an iodine atom. ^Rm1 is a substituent other than an iodine atom. ^L01 is a divalent linking group or a single bond. ^Vb0 is an alkylene group, a fluorinated alkylene group or a single bond. However, ^L01 and ^Vb0 will not simultaneously form a single bond. ^R0 is a fluorinated alkylene group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom. nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3. However, 2≦nb1+nb2+nb3≦5. ^Mm+ represents an m-valent organic cation. m is an integer greater than 1.]

{Negative ion portion of component (B0)} In the aforementioned formula (b0), R ^b is an alkali-degradable group. The so-called "alkali-degradable group" refers to a group having a degradability that can cleave at least a portion of the bonds in the structure of the alkali-degradable group by the action of an alkali developer. "Degradability that can cleave the aforementioned bonds by the action of an alkali developer" means that the solubility in the alkali developer is increased by decomposition by the action of a 0.1 to 30 mass % alkali developer (preferably at 23°C and by the action of a 2.38 mass % tetramethylammonium hydroxide aqueous solution). This is caused, for example, by the decomposition (hydrolysis) of the ester bond by the action of an alkali developer (alkali) to generate a hydrophilic group. Examples of the hydrophilic group include a carboxyl group and a hydroxyl group.

The alkali-decomposable group in ^Rb is not particularly limited to any group that can change the solubility of the component (B0) in the alkali developer by decomposing it with an alkali. Alkali-decomposable groups that have been proposed as components added to chemically amplified resist compositions can be used, for example, structures containing an ester bond. Among them, ^Rb in the aforementioned formula (b0) is preferably a group having a cyclic group containing a lactone.

The so-called "lactone-containing cyclic group" means a cyclic group having a ring (lactone ring) containing -O-C(=O)- in the cyclic skeleton. When the lactone ring is counted as the first ring, it is called a monocyclic group when it is only a lactone ring, and when it has other ring structures, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. As the lactone-containing cyclic group, any one can be used without particular limitation. Specifically, the groups represented by the following general formulas (a2-r-1) to (a2-r-8) can be cited.

[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 hydroxyl alkyl group or a cyano group; R" is a hydrogen atom, an alkyl group or a cyclic group containing a lactone; A" is an alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom which may also contain an oxygen atom (-O-) or a sulfur atom (-S-); n' is an integer of 0 to 2; and m' is 0 or 1. * indicates a bonding position.]

In the aforementioned formulas (a2-r-1) to (a2-r-8), the alkyl group in Ra' ²¹ is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably a straight chain or a branched chain. Specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, etc. are mentioned. Among them, methyl or ethyl is also preferred, and methyl is particularly preferred. As the alkoxy group in Ra' ²¹ , an alkoxy group having 1 to 6 carbon atoms is preferably an alkoxy group. The alkoxy group is preferably a straight chain or a branched chain. Specifically, a group in which the alkyl group listed as the aforementioned alkyl group in Ra' ²¹ is linked to an oxygen atom (-O-) is mentioned. As the halogen atom in Ra' ²¹ , a fluorine atom is preferred. As the halogenated alkyl group in Ra' ²¹ , there can be mentioned a group in which a part or all of the hydrogen atoms of the alkyl group in Ra' ²¹ are substituted by the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

For -COOR", -OC(=O)R", in Ra' ²¹ , R" is a hydrogen atom, an alkyl group or a cyclic group containing lactone. The alkyl group in R" may be any of a linear, branched or cyclic group, and preferably has 1 to 15 carbon atoms. When R" is a linear or branched alkyl group, preferably has 1 to 10 carbon atoms, more preferably has 1 to 5 carbon atoms, and particularly preferably is a methyl or ethyl group. When R" is a cyclic alkyl group, preferably has 3 to 15 carbon atoms, more preferably has 4 to 12 carbon atoms, and most preferably has 5 to 10 carbon atoms. Specifically, there can be exemplified a group obtained by removing one or more hydrogen atoms from a monocyclic alkane 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 polycyclic alkane such as a bicyclic alkane, a tricyclic alkane, or a tetracyclic alkane; and the like. More specifically, there can be exemplified a group obtained by removing one or more hydrogen atoms from a monocyclic alkane such as cyclopentane or cyclohexane; and a group obtained by removing one or more hydrogen atoms from a polycyclic alkane such as adamantane, norbornane, isoborneol, tricyclodecane, or tetracyclododecane. As the lactone-containing cyclic group in R", the same ones as those represented by the aforementioned general formulas (a2-r-1) to (a2-r-8) can be cited. As the hydroxyalkyl group in Ra' ²¹ , those having 1 to 6 carbon atoms are preferred, and specifically, groups in which at least one of the hydrogen atoms of the alkyl group in Ra' ²¹ is substituted by a hydroxyl group can be cited.

As Ra' ²¹ , it is also preferred that each of the above independently represents a hydrogen atom or a cyano group.

In the aforementioned 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 thereof include methylene, ethylene, n-propylene, isopropylene and the like. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is separated from the terminal of the aforementioned alkylene group or between carbon atoms, such as -O- _CH2- , _-CH2 -O- _CH2- , -S- _CH2- , _-CH2 -S-CH2- and the like. 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.

Specific examples of the groups represented by general formulae (a2-r-1) to (a2-r-8) are given below.

In the aforementioned formula (b0), R ^b is preferably a group having a cyclic group containing a lactone, and the groups represented by the aforementioned general formulas (a2-r-1) to (a2-r-8) are preferred, the groups represented by the aforementioned general formulas (a2-r-1) to (a2-r-2) are further preferred, and the group represented by the aforementioned general formula (a2-r-1) is particularly preferred.

In the aforementioned formula (b0), the cyclic organic group in ^R10 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.

The aliphatic hydrocarbon group as the monocyclic group in ^R10 is preferably a group obtained by removing two or more hydrogen atoms from a monocyclic alkane or a monocyclic alkene. The monocyclic alkane is preferably a group having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The monocyclic alkene is preferably a group having 3 to 6 carbon atoms, and specific examples thereof include cyclopentene and cyclohexene. The aliphatic hydrocarbon group of the polycyclic group in ^R10 is preferably a group obtained by removing two or more hydrogen atoms from a polycycloalkane or a polycycloalkene. The polycycloalkane is preferably a group having 7 to 12 carbon atoms, and specifically includes adamantane, norbornene, isobornene, tricyclodecane, tetracyclododecane, etc. Furthermore, the polycycloalkene is preferably a group having 7 to 12 carbon atoms, and specifically includes adamantane, norbornene, isoborane, tricyclodecene, tetracyclododecene, etc.

The aromatic hydrocarbon group in ^R10 is preferably a group obtained by removing two or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, more preferably a group obtained by removing two or more hydrogen atoms from benzene, naphthalene or anthracene, and even more preferably a group obtained by removing two or more hydrogen atoms from benzene.

As the substituent group which may have a cyclic organic group in ^R10 , for example, the same groups as those for Ra ^x5 mentioned above can be cited. In addition, a part of the carbon atoms (methylene etc.) constituting the organic group can also be substituted by a group containing a heteroatom. As the heteroatom mentioned here, an oxygen atom, a sulfur atom and a nitrogen atom can be cited. As the group containing a heteroatom, (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O) ₂ -, -S(=O) ₂ -O- and the like can be cited. That is, the cyclic organic group which may have a substituent in ^R10 may be a group obtained by removing two or more hydrogen atoms from an aromatic heterocyclic ring such as a pyridine ring and a thiophene ring; or a group obtained by removing two or more hydrogen atoms from an aliphatic heterocyclic ring such as tetrahydrofuran, tetrahydropyran, and tetrahydrothiophene.

The cyclic organic group in ^R10 may be a condensed ring group containing a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed. Examples of the aforementioned condensed ring include a polycycloalkane having a cross-linked ring system polycyclic skeleton in which one or more aromatic rings are condensed. Specific examples of the aforementioned cross-linked ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. As the aforementioned condensed ring group, a group containing a condensed ring in which two or three aromatic rings are condensed in a bicycloalkane is preferred.

In the above general formula (b0), ^R10 is preferably an aromatic hydrocarbon group which may have a substituent or a polycyclic alicyclic hydrocarbon group which may have a substituent, from the viewpoint of improving the dispersion uniformity of the (B0) component in the resist film. It is preferably a group obtained by removing two hydrogen atoms from an aromatic hydrocarbon group, a polycycloalkane or a polycycloalkene, or a condensed cyclic group containing a condensed ring of an aliphatic hydrocarbon ring and an aromatic ring.

Specifically, ^R10 is preferably a group represented by any one of the following chemical formulas (R10-1) to (R10-4), more preferably a group represented by the following chemical formula (R10-1), (R10-2) or (R10-4), and even more preferably a group represented by the following chemical formula (R10-4). In addition, the hydrogen atoms in the groups represented by the following chemical formulas (R10-1) to (R10-4) may be substituted by a substituent. Examples of the substituent include the same as those for Ra ^x5 above.

In the above formula (b0), L ⁰¹ is a divalent linking group or a single bond. L ⁰² is a divalent linking group. L ⁰³ is a divalent linking group. As the divalent linking group among L ⁰¹ , L ⁰² and L ⁰³ , a divalent linking group containing an oxygen atom can be cited as a preferred one. When L ⁰¹ , L ⁰² and L ⁰³ are divalent linking groups containing an oxygen atom, L ⁰¹ , L ⁰² and L ⁰³ may also contain an atom other than an oxygen atom. As the atom other than an oxygen atom, for example, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, etc. can be cited. Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), a carbonate bond (-OC(=O)-O-), and the like; a combination of the linking group containing an oxygen atom and an alkylene group, etc. The combination may further be linked to a sulfonyl group (-SO ₂ -).

More specifically, the divalent linking group in ^L01 , ^L02 and ^L03 includes -O-, -CO-, -OCO-, -COO-, _-SO2- , -N( ^Ra )-C(= ^O )-, -N(Ra)-, -C(Ra)(Ra)-N( ^Ra )-, -C(Ra)(N( ^Ra )( ^Ra ))- or -C(=O)-N( ^Ra )-, or a combination of the above non- ^hydrocarbon oxygen-containing linking groups and an ^alkylene group. Each ^Ra is independently ^a hydrogen atom or an alkyl group.

In the aforementioned formula (b0), ^L01 is preferably a divalent linking group, more preferably a divalent linking group containing an oxygen atom, more preferably -OCO-, -COO- or -C(=O)-N( ^Ra )-, or a combination of the aforementioned non-hydrocarbon linking group containing an oxygen atom and an alkylene group, and particularly preferably -OCO-, -COO- or a combination of the aforementioned non-hydrocarbon linking group containing an oxygen atom and an alkylene group.

In the aforementioned formula (b0), ^L02 is preferably a divalent linking group containing an oxygen atom, preferably -OCO-, -COO- or -C(=O)-N( ^Ra )-, and particularly preferably -OCO-, -COO- or -C(=O)-NH-.

In the above formula (b0), ^L03 is preferably a divalent linking group containing an oxygen atom, more preferably -OCO-, -COO- or -C(=O)-N(R ^a )-, and particularly preferably -OCO- or -COO-.

In the above formula (b0), as the substituent other than the iodine atom in ^Rm1 , there can be mentioned a hydroxyl group, an alkyl group, a fluorinated alkyl group, a fluorine atom, a chlorine atom, etc. As the alkyl group and the fluorinated alkyl group, an alkyl group having 1 to 5 carbon atoms is preferred, and a methyl group or an ethyl group is more preferred.

In the above formula (b0), the alkylene group and the fluorinated alkylene group in ^Vb0 are each preferably those having 1 to 4 carbon atoms, more preferably those having 1 to 3 carbon atoms. Examples of the fluorinated alkylene group in ^Vb0 include those in which a part or all of the hydrogen atoms of the alkylene group are substituted with fluorine atoms. Among the above, ^Vb0 is also preferably an alkylene group or a fluorinated alkylene group, more preferably an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group having 1 to 4 carbon atoms, and more preferably a _methylene group ( _{-CH2- )} , -CH( _CF3 )-, _{-CH2CH2CF2- or -CH2CH2CHF-} .

For example, as -L ⁰¹ -Vb ⁰ - in the general formula (b0) above, there can be mentioned any one of the linking groups represented by the following general formulas (b0-r-1) to (b0-r-7).

[In the formula, L ⁰¹¹ is an alkylene group having 1 to 5 carbon atoms or a single bond. L ⁰¹² is a divalent saturated alkyl group having 1 to 30 carbon atoms or a single bond. ^{Vb 01} is a fluorinated alkylene group having 1 to 4 carbon atoms or a single bond. However, L ⁰¹² and Vb ⁰¹ cannot be single bonds at the same time.]

In the aforementioned formulae (b0-r-1), (b0-r-2) and (b0-r-5) to (b0-r-7), the divalent saturated alkyl group in L ⁰¹² 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. As -L ⁰¹ -Vb ⁰ - in the aforementioned general formula (b0), the linking group represented by any of the general formulae (b0-r-1) to (b0-r-2) is particularly preferred.

In the above formula (b0), ^R0 is a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom. ^R0 is preferably a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom, more preferably a perfluoroalkyl group having 1 to 5 carbon atoms or a fluorine atom, and more preferably a fluorine atom.

In the above formula (b0), nb1 represents the number of iodine atoms (I), which is an integer of 1 to 4, preferably 1 to 3, and more preferably 2 or 3. nb2 represents the number of 1 to 4, preferably 1 or 2, and more preferably 1. nb3 represents the number of substituents (R ^m1 ) other than iodine atoms, which is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.

The following are preferred specific examples of the negative ion part of the component (B0). The negative ions represented by the chemical formulas (b0-an-101) to (b0-an-129) shown below are examples of the negative ion part when ^R10 in the aforementioned formula (b0) is a benzene ring. The negative ions represented by the chemical formulas (b0-an-201) to (b0-an-223) shown below are examples of the negative ion part when ^R10 in the aforementioned formula (b0) is a norbornene ring. The negative ions represented by the chemical formulas (b0-an-301) to (b0-an-322) shown below are examples of the negative ion part when ^R10 in the above formula (b0) is a bicyclic octane ring.

As the negative ion part of the component (B0), it is preferably selected from the group consisting of negative ions represented by the above chemical formulas (b0-an-101) to (b0-an-129), the group consisting of negative ions represented by the above chemical formulas (b0-an-201) to (b0-an-223), or the group consisting of negative ions represented by the above chemical formulas (b0-an-301) to (b0-an-322). Among these, the negative ion part of the component (B0) is preferably selected from the group consisting of negative ions represented by the above chemical formulas (b0-an-301) to (b0-an-322) from the viewpoint of more easily obtaining the effect of the present invention.

{Cation part of component (B0)} In the above formula (b0), M ^m+ is an m-valent organic cation. m is an integer greater than 1. The organic cation in M ^m+ is preferably an onium cation, and among them, a sulfonium cation and an iodonium cation are more preferred.

As the organic cation in M ^m+ , there can be cited organic cations represented by the following general formulas (ca-1) to (ca-3).

[In the formula, R ²⁰¹ to R ²⁰⁷ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. R ²⁰¹ to R ²⁰³ and R ²⁰⁶ to R ²⁰⁷ may form a ring together with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represents 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 cyclic group containing -SO ₂ - which may have a substituent. L ²⁰¹ represents -C(=O)- or -C(=O)-O-.]

In the above formulae (ca-1) to (ca-3), the aryl group in R ²⁰¹ to R ²⁰⁷ includes unsubstituted aryl groups having 6 to 20 carbon atoms, preferably phenyl and naphthyl. The alkyl group in R ²⁰¹ to R ²⁰⁷ is a chain or cyclic alkyl group having 1 to 30 carbon atoms. The alkenyl group in R ²⁰¹ to R ²⁰⁷ is preferably an alkenyl group having 2 to 10 carbon atoms. Examples of the substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ may have include alkyl groups, halogen atoms, halogenated alkyl groups, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the following general formulae (ca-r-1) to (ca-r-7).

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

Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, which may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group refers to a hydrocarbon group which is not aromatic. Moreover, an aliphatic hydrocarbon group may be saturated or unsaturated, and a saturated hydrocarbon group is generally preferred.

The aromatic alkyl group in ^R'201 is an alkyl group having an aromatic ring. The number of carbon atoms of the aromatic alkyl group is preferably 3 to 30, more preferably 5 to 30, 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. Specific examples of the aromatic ring possessed by the aromatic alkyl group in ^R'201 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocyclic rings in which a portion of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatoms in the aromatic heterocyclic ring include oxygen atoms, sulfur atoms, nitrogen atoms, and the like. Specific examples of the aromatic alkyl group in ^R'201 include a group obtained by removing one hydrogen atom from the aforementioned aromatic ring (aryl group: for example, phenyl, naphthyl, etc.), a group obtained by replacing one hydrogen atom of the aforementioned aromatic ring with an alkylene group (for example, benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl and other arylalkyl groups), etc. The aforementioned alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

The cyclic aliphatic hydrocarbon group in ^R'201 can be an aliphatic hydrocarbon group containing a ring in the structure. As the aliphatic hydrocarbon group containing a ring in the structure, there can be mentioned 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 straight chain or branched chain aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is separated in the middle of a straight chain or branched chain aliphatic hydrocarbon group, etc. The aforementioned alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The aforementioned alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic alkyl group, a group obtained by removing one or more hydrogen atoms from a monocyclic alkane is preferred. The monocyclic alkane is preferably one having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. As a polycyclic alicyclic alkyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. The polycycloalkane is preferably a polycycloalkane having a cross-linked ring system with a polycyclic skeleton such as adamantane, norbornane, isoborneol, tricyclodecane, tetracyclododecane, etc.; a polycycloalkane having a polycyclic skeleton such as a condensed ring system with a steroid skeleton.

Among them, the cyclic aliphatic hydrocarbon group in ^R'201 is preferably a group obtained by removing one or more hydrogen atoms from a monocyclic alkane or a polycyclic alkane, more preferably a group obtained by removing one hydrogen atom from a polycyclic alkane, particularly preferably an adamantyl group and a norbornyl group, and most preferably an adamantyl group.

The linear or branched aliphatic alkyl group which can be bonded to the alicyclic alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. The linear aliphatic alkyl group is preferably a linear alkylene group, and specific examples thereof include methylene [-CH ₂ -], ethylene [-(CH ₂ ) ₂ -], trimethylene [-(CH ₂ ) ₃ -], tetramethylene [-(CH ₂ ) ₄ -], and pentamethylene [-(CH ₂ ) ₅ -]. The branched chain aliphatic hydrocarbon group is preferably a branched chain alkylene group, and specific examples thereof include -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH 3 )-, -C(CH 3 )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and the like alkylmethylene groups; -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH 3 )-, -C(CH ₃ ) ₂ CH 2 -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ CH ₃ ) 2 - and the like alkylethylene groups; -CH(CH 3 )CH ₂ -, -CH(CH ₃ )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH ₂ CH ₃ )CH 2 -, -C(CH 2 CH 3 ) ₂ -CH ₂ - and the like alkylethylene groups; -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -, alkyltrimethylene, -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, alkyltetramethylene, _etc. , alkylalkylene, etc. The alkyl in the alkylalkylene is preferably a linear alkyl having 1 to 5 carbon atoms.

Furthermore, the cyclic hydrocarbon group in ^R'201 may also contain heteroatoms such as heterocyclic atoms. Specific examples include lactone-containing cyclic groups represented by the aforementioned general formulas (a2-r-1) to (a2-r-8), -SO ₂ -containing cyclic groups represented by the following general formulas (b5-r-1) to (b5-r-4), and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16).

As the substituent in the cyclic group of ^R'201 , for example, there can be mentioned an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, etc. 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 the most preferred. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, and 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 the most preferred. As the halogen atom as the substituent, a fluorine atom is preferred. Examples of the halogenated alkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, tert-butyl, etc., in which a part or all of the hydrogen atoms are replaced by the above-mentioned halogen atoms. The carbonyl group as a substituent is a group replacing the methylene group ( _-CH2- ) constituting the cyclic hydrocarbon group.

Chain alkyl groups which may have a substituent: The chain alkyl group as ^R'201 may be either a straight chain or a branched chain. As a straight chain alkyl group, the number of carbon atoms is preferably 1 to 20, more preferably 1 to 15, and most preferably 1 to 10. As a branched chain alkyl group, the number of carbon atoms is preferably 3 to 20, more preferably 3 to 15, and most preferably 3 to 10. Specific examples include 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, and the like.

Chain alkenyl groups which may have a substituent: The chain alkenyl group as ^R'201 may be either a straight chain or a branched chain, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of straight chain alkenyl groups include vinyl, propenyl (allyl), butynyl, etc. Examples of branched chain alkenyl groups include 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, 2-methylpropenyl, etc. Among the above, straight chain alkenyl groups are also preferred, vinyl and propenyl are preferred, and vinyl is particularly preferred.

Examples of the substituent in the chain alkyl or alkenyl group of ^R'201 include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the cyclic group in the above ^R'201 .

In addition to the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, or the chain alkenyl group which may have a substituent as represented by ^R'201 , the cyclic group which may have a substituent or the chain alkyl group which may have a substituent may also be the same as the acid-liquidable group represented by the above formula (a1-r-2).

Among them, ^R'201 is also 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 group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane; a cyclic group containing lactone represented by the aforementioned general formulas (a2-r-1) to (a2-r-8); and a cyclic group containing _-SO2- represented by the following general formulas (b5-r-1) to (b5-r-4).

In the above general formulas (ca-1) to (ca-3), when ^R201 to ^R203 and ^R206 to ^R207 are bonded to each other and to form a ring together with the sulfur atom in the formula, they may be bonded via a sulfur atom, an oxygen atom, a nitrogen atom or other heteroatom, or a carbonyl group, -SO-, _-SO2- , _-SO3- , -COO-, -CONH- or -N( _RN )- (wherein _RN is an alkyl group having 1 to 5 carbon atoms). The ring formed is preferably a 3- to 10-membered ring containing the sulfur atom in one ring of the ring skeleton, and particularly preferably a 5- to 7-membered ring. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thiadone ring, a thiadone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

R ²⁰⁸ to R ²⁰⁹ each independently represent 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. When they are alkyl groups, they may be bonded to each other to form a ring.

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 cyclic group containing -SO ₂ - which may have a substituent. As the aryl group in R ²¹⁰ , there can be mentioned an unsubstituted aryl group having 6 to 20 carbon atoms, preferably a phenyl group and a naphthyl group. As the alkyl group in R ²¹⁰ , it is a chain or cyclic alkyl group, preferably having 1 to 30 carbon atoms. As the alkenyl group in R ²¹⁰ , it is preferably having 2 to 10 carbon atoms. As the cyclic group containing -SO ₂ - in R ²¹⁰ , there is no particular limitation, and any one can be used. Specifically, the groups represented by the following general formulae (b5-r-1) to (b5-r-4) are mentioned, and "polycyclic groups containing -SO ₂ -" are preferred, and the group represented by general formula (b5-r-1) is more preferred.

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

In the above general formulas (b5-r-1) to (b5-r-2), B" is an alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom which may contain an oxygen atom or a sulfur atom. As B", an alkylene group having 1 to 5 carbon atoms or -O- is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is more preferred.

In the aforementioned general formulas (b5-r-1) to (b5-r-4), Rb' ⁵¹ each independently represents 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, wherein each independently represents a hydrogen atom or a cyano group is preferred.

Specific examples of the groups represented by the following general formulae (b5-r-1) to (b5-r-4) can be cited: "Ac" in the formulae represents an acetyl group.

As preferred cations represented by the above formula (ca-1), specifically, there can be mentioned cations represented by the following chemical formulas.

[In the formula, g1, g2, and g3 represent repetition numbers, g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20.]

[In the formula, R" ²⁰¹ is a hydrogen atom or a substituent, and examples of the substituent include the same substituents as those mentioned above as the substituents which ^R201 to ^R207 and ^R210 to ^R212 may have.]

Specific examples of the preferred cation represented by the above formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

Specific examples of preferred cations represented by the above formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

As the organic cation for M ^m+ , at least one selected from the group consisting of cations represented by the aforementioned general formulas (ca-1) to (ca-3) is preferred, and among these, the cation represented by the aforementioned general formula (ca-1) is also preferred. In particular, from the viewpoint of high sensitivity, the cation represented by the aforementioned formula (ca-1) is preferred, and as a substituent, it is preferred to have an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, a sulfonyl group, etc. For example, a cation selected from the group consisting of cations represented by the aforementioned chemical formulas (ca-1-44), (ca-1-71) to (ca-1-84) is particularly preferred.

Specific examples of the component (B0) are given below, but are not limited to these.

The component (B0) in the above is preferably selected from the group consisting of compounds represented by the above chemical formulas (B0-1) to (B0-29). Or the component (B0) in the above is preferably selected from the group consisting of compounds represented by the above chemical formulas (B0-1) to (B0-12), selected from the group consisting of compounds represented by the above chemical formulas (B0-13) to (B0-18), or selected from the group consisting of compounds represented by the above chemical formulas (B0-19) to (B0-29). Among these, the component (B0) is preferably selected from the group consisting of compounds represented by the above chemical formulas (B0-19) to (B0-29).

In the resist composition of the present embodiment, the component (B0) may be a single type or two or more types may be used in combination. In the resist composition of the present embodiment, the content of the component (B0) is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, and even more preferably 20 to 35 parts by mass relative to 100 parts by mass of the component (A). If the content of the component (B0) is above the lower limit of the above-mentioned preferred range, high sensitivity can be achieved for resist pattern formation, and it becomes easy to improve lithography characteristics such as CDU and fine resolution. On the other hand, if it is below the upper limit of the above-mentioned preferred range, the sensitivity can be well maintained. In addition, when the components of the resist composition are dissolved in an organic solvent, a uniform solution can be easily obtained, which is preferred because the storage stability of the resist composition is improved.

The proportion of the component (B0) in the total amount of the component (B) is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 95% by mass or more. The proportion of the component (B0) in the total amount of the component (B) may also be 100% by mass.

･Regarding component (B1) The component (B) in the resistor composition of this embodiment may contain an acid generator component other than the above-mentioned component (B0) (hereinafter also referred to as "component (B1)"). The component (B1) is not particularly limited, and any acid generator proposed as a chemically amplified resistor composition can be used. As such acid generators, there can be cited onium salt acid generators such as iodonium salts or sulfonium salts, oxime sulfonate acid generators; diazomethane acid generators such as dialkyl or diaryl sulfonyl diazomethanes and poly (disulfonyl) diazomethanes; nitrobenzene sulfonate acid generators, imine sulfonate acid generators, disulfonate acid generators, and the like.

In the inhibitor composition of this embodiment, the (B1) component may be used alone or in combination of two or more. When the inhibitor composition of this embodiment contains the (B1) component, the proportion of the (B1) component in the total (B) component is preferably less than 50% by mass, more preferably less than 40% by mass, more preferably less than 30% by mass, and particularly preferably less than 20% by mass.

<Other components> The resist composition of this embodiment may further contain other components in addition to the above-mentioned (A) component and (B) component. Examples of other components include the following components (D), (E), (F), and (S). ≪Alkaline component (D)≫ The resist composition of this embodiment may contain, in addition to the (A) component and (B) component, an alkaline component (component (D)) that captures the acid generated by exposure (i.e., controls the diffusion of the acid). The (D) component acts as a quencher (acid diffusion controller) in the resist composition that captures the acid generated by exposure. As the (D) component, for example, a photodisintegration base (D1) (hereinafter also referred to as "(D1) component") that loses acid diffusion control due to decomposition by exposure, a nitrogen-containing organic compound (D2) (hereinafter also referred to as "(D2) component") that is not equivalent to the (D1) component, etc. Among these, the photodisintegration base ((D1) component) is preferred because the properties of high sensitivity, reduced roughness, and suppression of coating defects are easily improved. The compounds exemplified as the (D1) component described later may also be used as the above-mentioned acid generator component ((B) component) by combining with other compounds.

･ Regarding component (D1) Component (D1) is not particularly limited as long as it loses its acid diffusion control property by decomposition due to exposure, and is preferably selected from the group consisting of one or more compounds represented by the following general formula (d1-1) (hereinafter also referred to as "component (d1-1)"), compounds represented by the following general formula (d1-2) (hereinafter also referred to as "component (d1-2)"), and compounds represented by the following general formula (d1-3) (hereinafter also referred to as "component (d1-3)"). Components (d1-1) to (d1-3) lose their acid diffusion control property (alkalinity) by decomposition in the exposed part of the resist film, and therefore cannot function as a quencher, but function as a quencher in the unexposed part of the resist film.

[In the formula, ^Rd1 to ^Rd4 are cyclic groups which may have substituents, chain alkyl groups which may have substituents, or chain alkenyl groups which may have substituents. However, in formula (d1-2), ^Rd2 is assumed to be a group in which the carbon atom adjacent to the S atom is not bonded to a fluorine atom. ^Yd1 is a single bond or a divalent linking group. m is an integer greater than 1, and ^Mm+ is independently an m-valent organic cation.]

{(d1-1) component} ･･In the negative ion part 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 examples thereof include the same ones as those for each of the above R' ^201. Among these, Rd ¹ is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkyl group which may have a substituent. Examples of the substituent which may have these groups 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 each of the above general formulas (a2-r-1) to (a2-r-8), an ether bond, an ester bond, or a combination thereof. When an ether bond or ester bond is contained as a substituent, an alkylene group may be interposed therebetween, and in this case, the substituent is preferably a linking group represented by each of the above formulae (y-al-1) to (y-al-5). Furthermore, when the aromatic alkyl group, aliphatic cyclic group or chain alkyl group in ^Rd1 has a substituent in the linking group represented by each of the above general formulae (y-al-1) to (y-al-7), in the above general formulae (y-al-1) to (y-al-7), the carbon atom constituting the aromatic alkyl group, aliphatic cyclic group or chain alkyl group in ^Rd1 in formula (d3-1) is bonded to ^V'101 in the above general formulae (y-al-1) to (y-al-7). Preferred examples of the aromatic hydrocarbon group include phenyl, naphthyl, and a polycyclic structure containing a bicyclic octane skeleton (a polycyclic structure consisting of a bicyclic octane skeleton and a cyclic structure other than the bicyclic octane skeleton). Preferred examples of the aliphatic cyclic group include a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isoborneol, tricyclodecane, tetracyclododecane, etc. The aforementioned chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples include straight chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl; and branched chain alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl.

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

Preferred specific examples of the negative ion part of the component (d1-1) are shown below.

･･In the cation part formula (d1-1), M ^m+ is an m-valent organic cation. As the organic cation of M ^m+ , preferably, there can be cited the same cations as those represented by the aforementioned general formulas (ca-1) to (ca-3), preferably the cation represented by the aforementioned general formula (ca-1), and more preferably the cations represented by the aforementioned formulas (ca-1-1) to (ca-1-84). The component (d1-1) may be used alone or in combination of two or more.

{(d1-2) component} ･･In the negative ion part 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 same ones as those for the above-mentioned R' ²⁰¹ can be cited. However, in Rd ² , a fluorine atom is not bonded to the carbon atom adjacent to the S atom (not substituted by fluorine). Thereby, the negative ion of the component (d1-2) becomes a moderately weak acid negative ion, and the quenching property as the component (D) is improved. As Rd ² , a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent is preferred, and an aliphatic cyclic group which may have a substituent is more preferred.

The chain alkyl group preferably has 1 to 10 carbon atoms, and 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, isoborneol, tricyclodecane, tetracyclododecane, etc. (which may also have a substituent); a group obtained by removing one or more hydrogen atoms from camphor are preferred.

The alkyl group of ^Rd2 may have a substituent, and examples of the substituent include the same substituents as those possessed by the alkyl group (aromatic alkyl group, aliphatic cyclic group, chain alkyl group) in ^Rd1 of the aforementioned formula (d1-1).

Preferred specific examples of the negative ion part of the component (d1-2) are shown below.

･･In the cation part formula (d1-2), M ^m+ is an m-valent organic cation, which is the same as M ^m+ in the above formula (d1-1). The component (d1-2) may be used alone or in combination of two or more.

{(d1-3) component} ･･In the negative ion part formula (d1-3), Rd ³ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and the same ones as those for R' ²⁰¹ mentioned above can be cited, and a cyclic group, a chain alkyl group, or a chain alkenyl group containing a fluorine atom is preferred. Among them, a fluorinated alkyl group is also preferred, and the same ones as the fluorinated alkyl group for Rd ¹ mentioned above are more preferred.

In formula (d1-3), ^Rd4 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 examples thereof include the same as those for ^R'201 above. Among them, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group which may have a substituent is preferred. The alkyl group in ^Rd4 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl. A portion of the hydrogen atoms of the alkyl group in ^Rd4 may be substituted by a hydroxyl group, a cyano group, or the like. The alkoxy group in Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, and tert-butoxy. Among them, methoxy and ethoxy are preferred.

The alkenyl group in ^Rd4 may be the same as the alkenyl group in ^R'201 , preferably vinyl, propenyl (allyl), 1-methylpropenyl, 2-methylpropenyl. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

The cyclic group in Rd ⁴ may be the same as the cyclic group in R' ²⁰¹ , preferably an alicyclic group obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isoborneol, tricyclodecane, tetracyclododecane, or an aromatic group such as phenyl or naphthyl. When Rd ⁴ is an alicyclic group, the resist composition can be well soluble in an organic solvent, thereby improving the photolithography characteristics. Furthermore, when Rd ⁴ is an aromatic group, in photolithography using EUV or the like as an exposure light source, the light absorption efficiency of the resist composition is excellent, and the sensitivity or photolithography characteristics are improved.

In formula (d1-3), ^Yd1 is a single bond or a divalent linking group. As the divalent linking group in ^Yd1 , there are no particular limitations, and examples thereof include a divalent alkyl group (aliphatic alkyl group, aromatic alkyl group) which may have a substituent, a divalent linking group containing a heteroatom, and the like. Examples of these include the same divalent alkyl group which may have a substituent and a divalent linking group containing a heteroatom as those mentioned in the description of the divalent linking group in ^{Ya21 in formula (a2-1} ). ^Yd1 is preferably 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 preferred, and a methylene group or an ethylene group is more preferred.

Preferred specific examples of the negative ion part of the component (d1-3) are shown below.

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

The component (D1) may be any one of the components (d1-1) to (d1-3) mentioned above, or may be used in combination of two or more. When the resist composition contains the component (D1), the content of the component (D1) in the resist composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 12 parts by mass, and even more preferably 2 to 10 parts by mass relative to 100 parts by mass of the component (A).

The component (D1) preferably contains the above-mentioned component (d1-1). The content of the component (d1-1) in the whole component (D1) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The component (D1) may also consist only of the compound (d1-1).

(D1) Production method of component: The production method of the aforementioned components (d1-1) and (d1-2) is not particularly limited and can be produced by a known method. In addition, the production method of component (d1-3) is not particularly limited and can be produced, for example, by the same method as described in US2012-0149916.

･As for the component (D2), as the component (D), a nitrogen-containing organic compound component not equivalent to the above-mentioned component (D1) (hereinafter also referred to as "component (D2)" may be contained. The component (D2) is not particularly limited as long as it functions as an acid diffusion control agent and is not equivalent to the component (D1), and any known component may be used. Among them, aliphatic amines are also preferred, and secondary aliphatic amines or tertiary aliphatic amines are particularly preferred. The so-called aliphatic amine means an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of the aliphatic amine include amines (alkylamines or alkylolamines) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is substituted by an alkyl group or a hydroxyalkyl group having 12 or less carbon atoms. Specific examples of the alkylamines and alkylolamines 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 alkylolamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

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

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

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

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

≪At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxygen acids and their derivatives≫ The resist composition of the present embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxygen acids and their derivatives (hereinafter also referred to as "(E) component") for the purpose of preventing sensitivity degradation or improving resist pattern shape, preset stability over time, etc. Specific examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc., among which salicylic acid is preferred. Examples of phosphorus oxygen acids include phosphoric acid, phosphonic acid, phosphinic acid, etc., among which phosphonic acid is particularly preferred.

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 preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, relative to 100 parts by mass of the (A) component. By the above range, the photolithography characteristics can be further improved.

≪Fluorine additive component (F)≫ The resist composition of this embodiment may also contain a fluorine additive component (hereinafter also referred to as "(F) component") as a hydrophobic resin. The (F) component is used to impart hydrophobicity to the resist film, and when used as another resin of the (A) component, it can improve the photolithography characteristics. As the (F) component, for example, the fluorine-containing polymer compounds described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 can be used. More specifically, as the component (F), there can be cited a polymer having a constituent unit (f1) represented by the following general formula (f1-1). The polymer is preferably a polymer (homopolymer) consisting only of the constituent unit (f1) represented by the following formula (f1-1); a copolymer of the constituent unit (f1) and the aforementioned constituent unit (a1); a copolymer of the constituent unit (f1) and a constituent unit derived from acrylic acid or methacrylic acid and the aforementioned constituent unit (a1); and a copolymer of the constituent unit (f1) and the aforementioned constituent unit (a1) is more preferred. Among them, the aforementioned constituent unit (a1) copolymerized with the constituent unit (f1) is preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate or a constituent unit derived from 1-methyl-1-adamantyl (meth)acrylate, and more preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate.

[In the formula, R is the same as above, ^Rf102 and ^Rf103 each independently represent 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 ^Rf102 and ^Rf103 may be the same or different. ^nf1 is an integer from 0 to 5, and ^Rf101 is an organic group containing a fluorine atom.]

In the formula (f1-1), R bonded to the carbon atom at the α position is the same as described above. As R, a hydrogen atom or a methyl group is preferred. In the formula (f1-1), as the halogen atom of Rf ¹⁰² and Rf ¹⁰³ , a fluorine atom is preferred. As the alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ , the same as the alkyl group having 1 to 5 carbon atoms of the above R can be cited, and a methyl group or an ethyl group is preferred. As the halogenated alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ , specifically, a group in which a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted by a halogen atom can be cited. As the halogen atom, a fluorine atom is preferred. ^Rf102 and ^Rf103 are preferably hydrogen atom, fluorine atom or alkyl group having 1 to 5 carbon atoms, preferably hydrogen atom, fluorine atom, methyl group or ethyl group, and more preferably hydrogen atom. In formula (f1-1), ^nf1 is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

In formula (f1-1), ^Rf101 is an organic group containing a fluorine atom, preferably a fluorine-containing alkyl group. The fluorine-containing alkyl group may be any of a linear chain, a branched chain or a ring, preferably having 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. In addition, among the fluorine-containing alkyl groups, it is preferred that 25% or more of the hydrogen atoms in the alkyl group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more are fluorinated because the hydrophobicity of the resist film during immersion exposure can be improved. Among them, ^Rf101 is preferably a fluorinated alkyl group having 1 to 6 carbon atoms, and particularly preferably a trifluoromethyl group, _-CH2 - _CF3 , _-CH2 - _CF2 - _CF3 , -CH( _CF3 ) ₂ , _-CH2 - _CH2 - _CF3 , and _-CH2 - _CH2 - _CF2 - _CF2 - _CF2 - _CF3 .

The weight average molecular weight (Mw) of the (F) component (based on polystyrene conversion by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. When it is set below the upper limit of the range, it has sufficient solubility in the resist solvent when used as a resist, and when it is set above the lower limit of the range, the water repellency of the resist film is good. The dispersion degree (Mw/Mn) of the (F) component is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

In the resist composition of this embodiment, the (F) component may be used alone or in combination of two or more. When the resist composition contains the (F) component, the content of the (F) component is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the (A) component.

≪Organic solvent component (S)≫ The resist composition of this embodiment can be produced by dissolving the resist material in an organic solvent component (hereinafter referred to as "(S) component"). In the resist composition of this embodiment, the (S) component can be used alone or as a mixed solvent of two or more. Among them, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, ethyl lactate (EL), and cyclohexanone are preferred.

In addition, as the (S) component, a mixed solvent of PGMEA and a polar solvent is also preferred. The mixing ratio (mass ratio) can be appropriately determined by taking into account the compatibility of PGMEA and the polar solvent. As the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is preferred. At this time, as a mixing ratio, the mass ratio of the former to the latter is preferably set at 70:30 to 95:5. The amount of the (S) component used is not particularly limited, and the concentration that can be applied to the substrate can be appropriately set according to the coating film thickness. Generally, the (S) component is used to make the solid component concentration of the resist composition 0.1 to 20 mass%, preferably in the range of 0.2 to 15 mass%.

The resist composition of this embodiment can be removed from impurities, etc. by using a polyimide porous membrane, a polyamide imide porous membrane, etc. after dissolving the above-mentioned resist material in the (S) component. For example, a filter formed by a polyimide porous membrane, a filter formed by a polyamide imide porous membrane, a filter formed by a polyimide porous membrane and a polyamide imide porous membrane, etc. can also be used to filter the resist composition. As the aforementioned polyimide porous membrane and the aforementioned polyamide imide porous membrane, for example, those described in Japanese Patent Publication No. 2016-155121 can be exemplified.

The resist composition of the present embodiment described above contains a base component (A) and a compound (B0) represented by the general formula (b0). Since the compound (B0) has an iodine atom, it has high absorption of EUV (extreme ultraviolet) and EB (electron beam). On the other hand, if it has an iodine atom, the hydrophobicity of the material itself becomes stronger, and there is a tendency for the solubility in alkaline developer to decrease. Since the compound (B0) used in the present embodiment has an alkali-degradable group (R ^b ) in its structure, it will be hydrolyzed by the action of the alkaline developer (alkali), thereby improving the solubility of the resist film in the alkaline developer. That is, in the resist composition, by containing a compound (B0) having both an iodine atom and an alkali-degradable group, the sensitivity and fine resolution can be improved. In addition, since compound (B0) has a cyclic organic group ( ^R10 ), which is a relatively large structure, the diffusion length of the acid can be suppressed to an appropriate degree, and the affinity with the substrate component can be adjusted to be high. Therefore, the in-plane uniformity (CDU) of the pattern size is improved. Therefore, if the resist composition of the present embodiment containing compound (B0) can achieve high sensitivity when forming a resist pattern, it can be inferred that the photolithography characteristics such as CDU and fine resolution can be improved.

(Resist pattern forming method) The resist pattern forming method of the second aspect of the present invention comprises the steps of forming a resist film on a support using the resist composition of the first aspect of the present invention, exposing the resist film, and developing the exposed resist film to form a resist pattern. As one embodiment of the resist pattern forming method, for example, a resist pattern forming method performed as follows can be cited.

First, the resist composition of the above-mentioned implementation form is applied on a support by a spinner, etc., and then baked (post-exposure baking (PAB)) for example, at a temperature of 80 to 150°C for 40 to 120 seconds, preferably for 60 to 90 seconds to form a resist film. Second, the resist film is selectively exposed by exposing through a mask (mask pattern) formed with a certain pattern or by direct exposure of electron beams without a mask pattern, etc., and then baked (post-exposure baking (PEB)) for example, at a temperature of 80 to 150°C for 40 to 120 seconds, preferably for 60 to 90 seconds. Next, the resist film is subjected to a developing process. In the case of an alkaline developing process, the developing process is performed using an alkaline developer, and in the case of a solvent developing process, a developer containing an organic solvent (organic developer) is used.

After the development process, it is preferred to perform a rinse process. In the case of an alkaline development process, it is preferred to use pure water for the rinse process, and in the case of a solvent development process, it is preferred to use a rinse solution containing an organic solvent. In the case of a solvent development process, after the above-mentioned development process or rinse process, the developer or rinse solution attached to the pattern can also be removed by a supercritical fluid. After the development process or rinse process, drying is performed. In addition, according to the situation, a baking process (post-baking) can also be performed after the above-mentioned development process.

The support is not particularly limited, and any known support may be used, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon wafer, a metal substrate such as copper, chromium, iron, aluminum, or a glass substrate may be used. As a material for the wiring pattern, copper, aluminum, nickel, gold, etc. may be used.

The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, _F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. can be used.

The exposure method of the resist film can be general exposure (dry exposure) in an inert gas such as air or nitrogen, or liquid immersion exposure (Liquid Immersion Lithography). Liquid immersion exposure is an exposure method in which a solvent (liquid immersion medium) having a refractive index greater than that of air is filled between the resist film and the lens at the lowest position of the exposure device in advance, and exposure is performed in this state (immersion exposure). As the liquid immersion medium, a solvent having a refractive index greater than that of air and smaller than that of the exposed resist film is preferred, such as water, fluorine-based inert liquid, silicon-based solvent, hydrocarbon-based solvent, etc. As the liquid immersion medium, water is preferably used.

As an alkaline developer used in the alkaline developing process, for example, a 0.1-10 mass % tetramethylammonium hydroxide (TMAH) aqueous solution can be cited. As an organic solvent contained in an organic developer used in the solvent developing process, any organic solvent that can dissolve the (A) component (the (A) component before exposure) can be selected appropriately from known organic solvents. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, hydrocarbon solvents, etc. can be cited.

Examples of the ester solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

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

A known additive may be added to the organic developer as necessary. As such an additive, for example, a surfactant may be mentioned. As the surfactant, there is no particular limitation, for example, an ionic or non-ionic fluorine-based and/or silicon-based surfactant may be used.

The developing process can be carried out by a known developing method, for example, a method of immersing a support in a developer for a certain period of time (immersion method), a method of filling the surface of a support with the developer by surface tension and leaving it for a certain period of time (stirring method), a method of spraying the developer on the surface of a support (spraying method), a method of continuously coating the developer on a support rotating at a certain speed while scanning a developer coating nozzle at a certain speed (dynamic distribution method), etc.

As an organic solvent contained in the rinse solution used in the rinse treatment after the development process in the solvent development process, for example, among the organic solvents listed as the organic solvents used in the aforementioned organic developer, those that do not easily dissolve the resist pattern can be appropriately selected and used. Usually, at least one type of solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. These organic solvents can be used alone or in combination of two or more. It is also possible to use a mixture of organic solvents other than the above or water.

The rinsing treatment (cleaning treatment) using the rinsing liquid can be carried out by a known rinsing method. Examples of the rinsing treatment method include a method of continuously applying the rinsing liquid to a support body rotating at a certain speed (rotation coating method), a method of immersing the support body in the rinsing liquid for a certain period of time (immersion method), and a method of spraying the rinsing liquid on the surface of the support body (spraying method).

According to the resist pattern forming method of the present embodiment described above, by using the above-mentioned resist composition, high sensitivity can be achieved when forming a resist pattern, and a resist pattern with improved lithography characteristics such as CDU and fine resolution can be formed.

The resist composition of the above-mentioned embodiment and the various materials used in the pattern forming method of the above-mentioned embodiment (such as the resist solvent, the developer, the rinse solution, the anti-reflection film forming composition, the topcoat forming composition, etc.) preferably do not contain impurities such as metal, metal salt containing halogen, acid, base, sulfur atom or phosphorus atom. Among them, as impurities containing metal atoms, Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li or salts thereof can be cited. The impurity content of these materials is preferably 200 ppb or less, more preferably 1 ppb or less, more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

(Compound represented by general formula (b0)) The compound of the third embodiment of the present invention is a compound represented by the following general formula (b0) (compound (B0)).

[In the formula, ^Rb is an alkali-decomposable group. ^L03 is a divalent linking group. ^Rl0 is a cyclic organic group which may have a substituent. ^L02 is a divalent linking group. I is an iodine atom. ^Rm1 is a substituent other than an iodine atom. ^L01 is a divalent linking group or a single bond. ^Vb0 is an alkylene group, a fluorinated alkylene group or a single bond. However, ^L01 and ^Vb0 will not simultaneously form a single bond. ^R0 is a fluorinated alkylene group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom. nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3. However, 2≦nb1+nb2+nb3≦5. ^Mm+ represents an m-valent organic cation. m is an integer greater than 1.]

The compound represented by the general formula (b0) is the same as the component (B0) in the inhibitor composition of the first aspect of the present invention. The descriptions of R ^b , L ⁰³ , R1 ⁰ , L 02 , R ^m1 , L ⁰¹ , Vb ⁰ , R ⁰ , nb1 , nb2 , nb3 , M ^m+ and m in the general formula (b0) are the same as those described above. For the compound in this embodiment, it is preferred that R ^b in the general formula (b0) has a cyclic group containing a ^lactone , and it is more preferred that it is a group represented by each of the general formulas (a2-r-1) to (a2-r-8), and it is more preferred that it is a group represented by each of the general formulas (a2-r-1) to (a2-r-2), and it is particularly preferred that it is a group represented by the general formula (a2-r-1). In the compounds of this embodiment, -L ⁰¹ -Vb ⁰ - in the general formula (b0) is preferably a linking group represented by any one of the following general formulas (b0-r-1) to (b0-r-7). In formulas (b0-r-1), (b0-r-2) and (b0-r-5) to (b0-r-7), the description of L ⁰¹² is the same as the above description. As -L ⁰¹ -Vb ⁰ - in the general formula (b0), a linking group represented by any one of the general formulas (b0-r-1) to (b0-r-2) is particularly preferred.

[In the formula, L ⁰¹¹ is an alkylene group having 1 to 5 carbon atoms or a single bond. L ⁰¹² is a divalent saturated alkyl group having 1 to 30 carbon atoms or a single bond. ^{Vb 01} is a fluorinated alkylene group having 1 to 4 carbon atoms or a single bond. However, L ⁰¹² and Vb ⁰¹ cannot be single bonds at the same time.]

As specific examples of the compounds of this embodiment, there can be cited the compounds whose negative ion part is the negative ion represented by the above chemical formulas (b0-an-101) to (b0-an-129) (when ^R10 in the above formula (b0) is a benzene ring), the compounds whose negative ion part is the negative ion represented by the above chemical formulas (b0-an-201) to (b0-an-223) (when ^R10 in the above formula (b0) is a norbornene ring), and the compounds whose negative ion part is the negative ion represented by the above chemical formulas (b0-an-301) to (b0-an-322) (when ^R10 in the above formula (b0) is a bicyclic octane ring). As specific examples of the compounds of this embodiment, more preferably, there can be mentioned the compounds represented by the above chemical formulas (B0-1) to (B0-29).

[Production method of the compound represented by general formula (b0)] Component (B0) can be produced using a known production method. For example, component (B0) can be obtained by salt exchange reaction of a precursor Bpre represented by the following general formula (Bpre) and a compound S0 represented by the following general formula (S-0).

[In the formula, ^Rb is an alkali-decomposable group. ^L03 is a divalent linking group. ^Rl0 is a cyclic organic group which may have a substituent. ^L02 is a divalent linking group. I is an iodine atom. ^Rm1 is a substituent other than an iodine atom. ^L01 is a divalent linking group or a single bond. ^Vb0 is an alkylene group, a fluorinated alkylene group or a single bond. However, ^L01 and ^Vb0 will not simultaneously form a single bond. ^R0 is a fluorinated alkylene group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom. nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3. ( _M1 " ^m+ ) _1/m is an ammonium cation. ^Z- is a non-nuclear ion. ^Mm+ represents an m-valent organic cation. m is an integer greater than 1.]

More specifically, the salt exchange reaction is a step of reacting the precursor Bpre with the compound S0 for salt exchange in a solvent such as water, dichloromethane, acetonitrile or chloroform to obtain the component (B0) by exchanging the cation of the precursor Bpre with the cation of the compound S0.

In the above formula, (M ₁ ″ ^m+ ) _1/m is an ammonium cation. The ammonium cation may be an ammonium cation derived from an aliphatic amine or an ammonium cation derived from an aromatic amine.

In the above formula, as Z- ^, there can be mentioned ions which can become an acid with lower acidity than the precursor Bpre, specifically, halogen ions such as bromine ^ion and chlorine ion; _BF4- ^, _AsF6- , ^{SbF6- ,} _{PF6- , ClO4-} ^, etc.

The reaction temperature is, for example, 0 to 100° C., and the reaction time is, for example, from 10 minutes to 24 hours.

After the salt exchange reaction is completed, the compound (B0) in the reaction solution can be isolated and purified. For the isolation and purification, conventionally known methods can be used, for example, a suitable combination of concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used. The structure of the compound obtained as described above can be identified by general organic analysis methods such as ¹ H-nuclear magnetic resonance (NMR) spectroscopy, ¹³ C-NMR spectroscopy, ¹⁹ F-NMR spectroscopy, infrared absorption (IR) spectroscopy, mass analysis (MS), elemental analysis, X-ray crystallography, etc.

As a method for producing the precursor Bpre, for example, the following method 1 for producing the precursor Bpre can be cited.

Method 1 for producing precursor Bpre: Method 1 for producing precursor Bpre comprises: a step (step A) of reacting a compound represented by the following general formula (CA-00) (hereinafter referred to as "compound (CA00)") with a compound represented by the following general formula (X-00) (hereinafter referred to as "compound (X00)") to obtain a compound represented by the following general formula (Y-00) (hereinafter referred to as "compound (Y00)"), and a step (step B) of reacting compound (Y00) with a compound represented by the following general formula (Al-00) (hereinafter referred to as "compound (Al00)") to obtain precursor Bpre' represented by the following general formula (Bpre'). The precursor Bpre' is a compound used to obtain the compound (B0), and is a compound in which ^L01 and ^L02 in the general formula (b0) are ester bonds (-C(=O)-O-).

[In the formula, ^Rm1 is a substituent other than an iodine atom. nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3. However, 2≦nb1+nb2+nb3≦5. ^Vb0 is an alkylene group, a fluorinated alkylene group, or a single bond. ^R0 is a fluorinated alkylene group having 1 to 5 carbon atoms, a fluorine atom, or a hydrogen atom. ( _M1 ” ^m+ ) _1/m is an ammonium cation. m is an integer greater than 1. ^Rb is an alkali-decomposable group. ^L03 is a divalent linking group. ^Rl0 is a cyclic organic group which may have a substituent.]

Step A: Step A is a step of obtaining compound (Y00) by reacting compound (CA00) with compound (X00) in an organic solvent (acetonitrile, tetrahydrofuran, hexane, etc.).

For the reaction in step A, a condensation agent, an alkaline catalyst, etc. can be used. As the condensation agent, N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide (DIC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, carbonyldiimidazole (CDI), etc. can be specifically mentioned. As the alkaline catalyst, tertiary amines such as trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine, dimethylaminopyridine (DMAP), and pyrrolidinepyridine; diazabicyclononene (DBN), diazabicycloundecene (DBU), etc. can be specifically mentioned.

The reaction temperature is, for example, 0 to 80° C., and the reaction time is, for example, 10 minutes to 24 hours.

Step B: Step B is, for example, a step of reacting compound (Y00) with compound (Al00) in an organic solvent (such as dichloromethane) to obtain precursor Bpre'.

In step B, a condensing agent, an alkaline catalyst, etc. may be used similarly to step A. The reaction temperature of step B is, for example, 0 to 50°C, and the reaction time is, for example, more than 10 minutes and less than 24 hours.

Compound (A100) can be obtained by reacting a compound containing acetic anhydride having the same structure as the cyclic organic group ( ^R10 ) by alkylation (eg, tert-butyl esterification) with an alcohol having the same structure as the alkali-degradable group ( ^Rb ) (eg, lactone alcohol).

The compound of the present embodiment described above can be used as a preferred compound of the acid generator for the inhibitor composition of the first aspect of the present invention. In addition, the compound of the present embodiment can be used as an acid generator of the fourth aspect described below.

(Acid Generator) The acid generator of the fourth embodiment of the present invention contains the compound of the third embodiment (compound (B0)). The acid generator of this embodiment is particularly suitable as an acid generator component for the inhibitor composition of the first embodiment. [Example]

The present invention is described in more detail below through examples, but the present invention is not limited to these examples.

<Production of compounds> [Synthesis example of intermediates (1): Synthesis of intermediates-H1 to H4] Synthesis of intermediate-H1: In a 300 mL three-necked flask, 1,1'-carbonyldiimidazole (CDI) (4.60 g, 28.4 mmol) and acetonitrile (20 g) were added, and 3-hydroxy-4-iodobenzoic acid (CA1) (6.74 g, 25.5 mmol) dissolved in acetonitrile (20 g) was added dropwise over 30 minutes and reacted for 1 hour. Thereafter, compound (I-1) (9.5 g, 30.6 mmol) was added and reacted at 65°C for 3 hours. After cooling, ultrapure water (250 g) was added, and after stirring for 30 minutes, the precipitated solid was filtered. The filtrate was dissolved in methanol (100 g) again, added dropwise to methyl tert-butyl ether (MTBE) (500 g), and the precipitated solid was filtered. The filtrate was dried under reduced pressure to obtain intermediate-H1 (9.5 g, yield 67.0%).

Synthesis of intermediates-H2 to H4: 3-Hydroxy-4-iodobenzoic acid (CA1) was converted to the following carboxylic acids (CA2) to (CA4) at an equimolar ratio, and the same synthesis as that of intermediate-H1 was performed to obtain intermediate-H2 (12.0 g, yield 69.0%), intermediate-H3 (11.9 g, yield 68.5%), and intermediate-H4 (15.2 g, yield 73.5%).

[Synthesis Example of Intermediate (2): Synthesis of Intermediates-H5 to H7] Synthesis of Intermediate-H5: 3-Hydroxy-4-iodobenzoic acid (CA1) (6.74 g, 25.5 mmol) was added to carboxylic acid (CA2) (10.0 g, 25.5 mmol) and the same synthesis as that of Intermediate-H1 was performed except that Compound (I-1) (9.5 g, 30.6 mmol) was replaced with Compound (I-2) (11.6 g, 30.6 mmol) to obtain Intermediate-H5 (13.8 g, yield 72.0%).

Synthesis of Intermediate-H6: 3-Hydroxy-4-iodobenzoic acid (CA1) (6.74 g, 25.5 mmol) was added to carboxylic acid (CA2) (10.0 g, 25.5 mmol), and the same synthesis as that of Intermediate-H1 was performed except that Compound (I-1) (9.5 g, 30.6 mmol) was replaced with Compound (I-3) (11.0 g, 30.6 mmol) to obtain Intermediate-H6 (13.0 g, yield 70.0%).

Synthesis of intermediate-H7: 3-Hydroxy-4-iodobenzoic acid (CA1) (6.74 g, 25.5 mmol) was added to carboxylic acid (CA2) (10.0 g, 25.5 mmol), and the same synthesis as that of intermediate-H1 was performed except that compound (I-1) (9.5 g, 30.6 mmol) was replaced with compound (I-4) (11.5 g, 30.6 mmol) to obtain intermediate-H7 (13.6 g, yield 71.0%).

[Synthesis Example of Intermediates (3): Synthesis of Intermediates-AA, BA, and NA] Synthesis of Intermediate-AA: In a 500 mL three-necked flask, add a 1.06 M solution of lithium diisopropylamide (LDA) in tetrahydrofuran (THF)/hexane (87 mL, 92.3 mmol), cool to 5°C, add tert-butyl alcohol (8.0 g, 108.6 mmol) dissolved in THF (30 g), and react at 5°C or below for 2 hours. Thereafter, add compound (M-1) (15.0 g, 54.3 mmol) dissolved in THF (225 g), and react at 5°C or below for 2 hours. After the reaction solution was added to ultrapure water (205g) for 30 minutes, heptane (205g) was added, and the organic layer was removed after stirring for 30 minutes. After the aqueous layer was washed with heptane (100g) 3 times, MTBE (150g) and 10% citric acid aqueous solution (205g, 106.1mmol) were added, and the aqueous layer was removed after stirring for 30 minutes. The recovered organic layer was washed with ultrapure water (150g) 3 times, and the organic layer was concentrated using a rotary evaporator. The concentrate was recrystallized with ethyl acetate to obtain the intermediate -AA (11.1g, yield 58.3%).

Synthesis of intermediates-BA and NA: Compound (M-1) was replaced with the following compounds (M-2) and (M-3) at equimolar ratios, and the same synthesis as that of intermediate-AA was performed to obtain intermediates-BA and intermediates-NA.

[Synthesis example of intermediate (4): Synthesis of intermediates-LAA, LBA, LNA] Synthesis of intermediate-LAA1: In a 200mL three-necked flask, add intermediate-AA (11.2, 32.2mmol), α-hydroxy-γ-butyrolactone (lactone alcohol 1) (3.5g, 34.0mmol) and dichloromethane (180g), stir and dissolve at room temperature. Next, add diisopropylcarbodiimide (DIC) (6.2g, 48.4mmol) and dimethylaminopyridine (0.4g, 3.2mmol) and react at room temperature for 5 hours. Filter the reaction solution and transfer the recovered organic layer to a 300mL three-necked flask. Then, trifluoroacetic acid (TFA) (22 g, 193.2 mmol) was added and stirred at room temperature for 24 hours. The precipitated solid was filtered. The filtrate was dissolved in methanol (60 g) again, added dropwise to ultrapure water (600 g), and the precipitated solid was filtered. After repeating this operation twice, the filtrate was dried under reduced pressure to obtain the intermediate -LAA1 (9.1 g, yield 75.0%).

Synthesis of intermediates-LAA2 and LAA3: Lactone alcohol 1 was changed to the following lactone alcohol 2 and lactone alcohol 3 at equimolar ratio, and the same synthesis as the synthesis of intermediate-LAA1 was carried out to obtain intermediates-LAA2 and intermediates-LAA3.

Synthesis of intermediates-LBA1, LBA2, and LBA3: Intermediate-AA was converted to intermediate-BA at equimolar concentration, and each lactone alcohol 1 to 3 was used to perform the same synthesis as that of intermediate-LAA1 to obtain intermediates-LBA1, LBA2, and LBA3.

Synthesis of intermediates-LNA1 and LNA2: Intermediate-AA was converted to intermediate-NA at equimolar concentration, and lactone alcohol 1 and lactone alcohol 3 were used to perform the same synthesis as that of intermediate-LAA1 to obtain intermediates-LNA1 and LNA2.

[Synthesis Example of Precursor (1): Synthesis of Precursor (Bpre-01) to (Bpre-09)] Synthesis of Precursor (Bpre-01): In a 200 mL three-necked flask, intermediate-LBA1 (4.0, 16.1 mmol), intermediate-H1 (8.1 g, 14.5 mmol) and dichloromethane (180 g) were added and stirred at room temperature to dissolve. Next, diisopropylcarbodiimide (DIC) (3.1 g, 24.2 mmol) and dimethylaminopyridine (0.2 g, 1.6 mmol) were added and reacted at room temperature for 5 hours. The reaction solution was filtered and the filtrate was concentrated using a rotary evaporator. The concentrate was dissolved in acetonitrile (40 g), then dripped into MTBE (200 g), and the precipitated solid was filtered. The filtrate was dissolved in acetonitrile (50 g) again, then dripped into MTBE (400 g), and the precipitated solid was filtered. This operation was repeated twice, and the filtrate was dried under reduced pressure to obtain the precursor (Bpre-01) (8.6 g, yield 75.5%).

Synthesis of promotors (Bpre-02) to (Bpre-09): Using the carboxylic acid group (16.1 mmol) of each intermediate -LBA1 to LBA3 and the phenolic group (14.5 mmol) of the intermediate -H1 to H7, the same synthesis as the synthesis of the promotor (Bpre-01) was carried out to obtain promotors (Bpre-02) to (Bpre-09). The combination of carboxylic acid and intermediate used to obtain each promotor is shown below. Prodriver (Bpre-01): Combination of intermediate-LBA1 and intermediate-H1 Prodriver (Bpre-02): Combination of intermediate-LBA1 and intermediate-H2 Prodriver (Bpre-03): Combination of intermediate-LBA1 and intermediate-H3 Prodriver (Bpre-04): Combination of intermediate-LBA1 and intermediate-H4 Prodriver (Bpre-05): Combination of intermediate-LBA3 and intermediate-H2 Prodriver (Bpre-06): Combination of intermediate-LBA2 and intermediate-H2 Prodriver (Bpre-07): Combination of intermediate-LBA1 and intermediate-H5 Prodriver (Bpre-08): Combination of intermediate-LBA1 and intermediate-H6 Prodriver (Bpre-09): Combination of intermediate-LBA1 and intermediate-H7

[Synthesis Example of Precursor (2): Synthesis of Precursors (Bpre-13) to (Bpre-17)] Using the carboxylic acid group (16.1 mmol) of each intermediate - LNA1, LNA2 and the phenolic group (14.5 mmol) of the intermediate - H1, H2, H4, H5, the same synthesis as the synthesis of the precursor (Bpre-01) was carried out to obtain precursors (Bpre-13) to (Bpre-17). The combination of carboxylic acid and intermediate used to obtain each precursor is shown below. Prodriver (Bpre-13): Combination of intermediate-LNA1 and intermediate-H1 Prodriver (Bpre-14): Combination of intermediate-LNA1 and intermediate-H2 Prodriver (Bpre-15): Combination of intermediate-LNA1 and intermediate-H4 Prodriver (Bpre-16): Combination of intermediate-LNA2 and intermediate-H2 Prodriver (Bpre-17): Combination of intermediate-LNA1 and intermediate-H5

[Synthesis Example of Precursor (3): Synthesis of Precursors (Bpre-19) to (Bpre-26)] Using the carboxylic acid group (16.1 mmol) of each intermediate - LAA1, LAA2, LAA3 and the phenolic group (14.5 mmol) of the intermediate - H1, H2, H4, H5, H6, H7, the same synthesis as the synthesis of the precursor (Bpre-01) was carried out to obtain the precursors (Bpre-19) to (Bpre-26). The combination of carboxylic acid and intermediate used to obtain each precursor is shown below. Prodriver (Bpre-19): Combination of intermediate-LAA1 and intermediate-H1 Prodriver (Bpre-20): Combination of intermediate-LAA1 and intermediate-H2 Prodriver (Bpre-21): Combination of intermediate-LAA1 and intermediate-H4 Prodriver (Bpre-22): Combination of intermediate-LAA2 and intermediate-H2 Prodriver (Bpre-23): Combination of intermediate-LAA3 and intermediate-H2 Prodriver (Bpre-24): Combination of intermediate-LAA1 and intermediate-H5 Prodriver (Bpre-25): Combination of intermediate-LAA1 and intermediate-H6 Promotor (Bpre-26): Combination of intermediate-LAA1 and intermediate-H7

[Synthesis example of compound (B0): Synthesis of compound (B0-1) to compound (B0-29)] Synthesis of compound (B0-1): The precursor (Bpre-01) (7.9 g, 10.0 mmol) and salt exchange compound A (3.8 g, 11.0 mmol) were dissolved in dichloromethane (120 g), ultrapure water (120 g) was added, and the reaction was carried out at room temperature for 30 minutes. After the reaction was completed, the aqueous phase was removed, and the organic phase was washed 4 times with ultrapure water (120 g). The organic phase was concentrated and dried using a rotary evaporator to obtain compound (B0-1) (8.7 g, yield 96.5%).

Synthesis of Compounds (B0-2) to (B0-29): Except for changing the above-mentioned promotors (Bpre-02) to (Bpre-09), promotors (Bpre-13) to (Bpre-17), promotors (Bpre-19) to (Bpre-26) and the following salt exchange compounds A to D, the same synthesis as the synthesis of compound (B0-1) was carried out to obtain compounds (B0-2) to (B0-29).

Each of the obtained compounds was subjected to NMR measurement, and each structure was identified from the following analysis results.

Compound (B0-1): Combination of precursor (Bpre-01) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ(ppm)=7.67-7.90 (m, ArH+Ar-I, 17H), 7.53-7.63 (d, ArH, 4H), 6.94 (d, Ar-I, 1H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-2): Combination of precursor (Bpre-02) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.53-7.63 (d, ArH, 4H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-3): Combination of precursor (Bpre-03) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 9.48 (s, NH, 1H), 8.12 (m, Ar-I, 1H), 8.01 (d, Ar-I, 1H), 7.74-7.90 (m, ArH, 15H), 7.53-7.63 (d, ArH, 4H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (Lactone), 1H)

Compound (B0-4): Combination of precursor (Bpre-04) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 8.12 (d, Ar-I, 1H), 7.74-7.90 (m, ArH, 15H), 7.53-7.63 (d, ArH, 4H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2, 1H)

Compound (B0-5): Combination of precursor (Bpre-05) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.53-7.63 (d, ArH, 4H), 4.51-4.68 (m, CF2CH2+CH (lactone), 4H), 3.31 (m, CH (lactone), 1H), 2.59 (m, CH (lactone), 2H), 1.63-2.10 (m, CH2 (lactone), 4H)

Compound (B0-6): Combination of precursor (Bpre-06) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.53-7.63 (d, ArH, 4H), 5.51 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.50 (m, CH2 (lactone), 1H), 4.37 (m, CH2 (lactone), 1H), 2.86 (m, CH2 (lactone), 1H), 2.66 (m, CH2 (lactone), 1H)

Compound (B0-7): Combination of procatalyst (Bpre-07) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.53-7.63 (d, ArH, 4H), 5.90 (m, CF3CH, 1H), 5.39 (m, CH (lactone), 1H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-8): Combination of procatalyst (Bpre-08) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.53-7.63 (d, ArH, 4H), 5.39 (m, CH (lactone), 1H), 4.91-5.20 (m, CFCH, 1H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.95-4.20 (m, COOCH2CH2, 2H), 2.65 (m, CH2 (lactone), 1H), 2.30-2.45 (m, COOCH2CH2, 1H), 2.25 (m, CH2(lactone), 1H), 2.05 (m, COOCH2CH2, 1H)

Compound (B0-9): Combination of precursor (Bpre-09) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.53-7.63 (d, ArH, 4H), 5.39 (m, CH (lactone), 1H), 4.41 (m, CH2 (lactone), 1H), 4.05-4.25 (m, COOCH2CH2+CH2 (lactone), 3H), 2.63-2.73 (m, COOCH2CH2+CH2 (lactone), 3H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-10): Combination of precursor (Bpre-02) and salt exchange compound B ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.70-8.22 (m, ArH+Ar-I, 16H), 7.53-7.63 (d, ArH, 4H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.30-3.45 (m, SO2CH,1H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H), 1.09-1.90 (m, cyclohexyl, 10H)

Compound (B0-11): Combination of procatalyst (Bpre-02) and salt exchange compound C ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.77-7.99 (m, ArH+Ar-I, 13H), 7.53-7.63 (d, ArH, 4H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-12): Combination of procatalyst (Bpre-02) and salt exchange compound D ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 8.50 (d, ArH, 2H), 8.37 (d, ArH, 2H), 7.99 (d, Ar-I, 1H), 7.93 (t, ArH, 2H) 7.84 (d, Ar-I, 1H), 7.53-7.75 (d, ArH, 11H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-13): Combination of procatalyst (Bpre-13) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.74-7.90 (m, ArH+Ar-I, 17H), 6.94 (d, Ar-I, 1H), 6.30 (d, CH, 1H), 6.10 (d, CH, 1H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15 (m, CH, 2H), 3.00 (m, CH, 1H), 2.65 (m, CH2 (lactone), 1H), 2.38 (m, CH, 1H), 2.25 (m, CH2 (lactone), 1H), 1.30-1.50 (m, CH2, 2H)

Compound (B0-14): Combination of procatalyst (Bpre-14) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 6.30 (d, CH, 1H), 6.10 (d, CH, 1H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15 (m, CH, 2H), 3.00 (m, CH, 1H), 2.65 (m, CH2 (lactone), 1H), 2.38 (m, CH, 1H), 2.25 (m, CH2 (lactone), 1H), 1.30-1.50 (m, CH2, 2H)

Compound (B0-15): Combination of procatalyst (Bpre-15) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 8.12 (d, Ar-I, 1H), 7.74-7.90 (m, ArH, 15H), 6.30 (d, CH, 1H), 6.10 (d, CH, 1H), 5.39 (m, CH (lactone), 1H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15 (m, CH, 2H), 3.00 (m, CH, 1H), 2.65 (m, CH2 (lactone), 1H), 2.38 (m, CH, 1H), 2.25 (m, CH2 (lactone), 1H), 1.30-1.50 (m, CH2, 2H)

Compound (B0-16): Combination of procatalyst (Bpre-16) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 6.30 (d, CH, 1H), 6.10 (d, CH, 1H), 4.51-4.68 (m, CF2CH2+CH (lactone), 4H), 3.31 (m, CH (lactone), 1H), 3.15 (m, CH, 2H), 3.00 (m, CH, 1H), 2.59 (m, CH (lactone), 2H), 2.38 (m, CH, 1H), 1.63-2.10 (m, CH2 (Norbornene)+CH2 (lactone), 6H)

Compound (B0-17): Combination of procatalyst (Bpre-17) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 6.30 (d, CH, 1H), 6.10 (d, CH, 1H), 5.90 (m, CF3CH, 1H), 5.39 (m, CH (lactone), 1H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15 (m, CH, 2H), 3.00 (m, CH, 1H), 2.65 (m, CH2 (lactone), 1H),2.38 (m, CH, 1H), 2.25 (m, CH2 (lactone), 1H), 1.30-1.50 (m, CH2, 2H)

Compound (B0-18): Combination of procatalyst (Bpre-17) and salt exchange compound C ¹ H-NMR (DMSO, 400MHz): δ(ppm)=7.77-7.99 (m, ArH, 13H), 6.30 (d, CH, 1H), 6.10 (d, CH, 1H), 5.90 (m, CF3CH, 1H), 5.39 (m, CH (lactone), 1H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15 (m, CH, 2H), 3.00 (m, CH, 1H), 2.65 (m, CH2 (lactone), 1H),2.38 (m, CH, 1H), 2.25 (m, CH2 (lactone), 1H), 1.30-1.50 (m, CH2, 2H)

Compound (B0-19): Combination of procatalyst (Bpre-19) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.74-7.90 (m, ArH+Ar-I, 17H), 7.01-7.47 (m, ArH, 8H), 6.94 (d, Ar-I, 1H), 5.39 (m, CH (lactone), 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15-3.40 (m, CH, 2H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-20): Combination of procatalyst (Bpre-20) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (m, Ar-I, 1H), 7.74-7.90 (m, ArH+ Ar-I, 16H), 7.01-7.47 (m, ArH, 8H), 5.39 (m, CH (lactone), 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15-3.40 (m, CH, 2H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-21): Combination of procatalyst (Bpre-21) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 8.12 (m, Ar-I, 1H), 7.74-7.90 (m, ArH, 15H), 7.01-7.47 (m, ArH, 8H), 5.39 (m, CH (lactone), 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15-3.40 (m, CH, 2H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-22): Combination of procatalyst (Bpre-22) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (m, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.01-7.47 (m, ArH, 8H), 5.51 (m, CH (lactone), 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.51-4.68 (m, CF2CH2, 2H), 4.50 (m, CH2 (lactone), 1H), 4.37 (m, CH2 (lactone), 1H), 3.15-3.40 (m, CH, 2H), 2.86 (m, CH2 (lactone), 1H), 2.66 (m, CH2 (lactone), 1H)

Compound (B0-23): Combination of procatalyst (Bpre-23) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (m, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.01-7.47 (m, ArH, 8H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.51-4.68 (m, CF2CH2+ CH (lactone), 4H), 3.15-3.40 (m, CH, 3H), 2.59 (m, CH (lactone), 2H), 1.63-2.10 (m, CH2 (lactone), 4H)

Compound (B0-24): Combination of procatalyst (Bpre-24) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (m, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.01-7.47 (m, ArH, 8H), 5.90 (m, CF3CH, 1H), 5.51 (m, CH (lactone), 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.50 (m, CH2 (lactone), 1H), 4.37 (m, CH2 (lactone), 1H), 3.15-3.40 (m, CH, 2H), 2.86 (m, CH2 (lactone), 1H), 2.66 (m, CH2 (lactone), 1H)

Compound (B0-25): Combination of precursor (Bpre-25) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.01-7.47 (m, ArH, 8H), 5.39 (m, CH (lactone), 1H), 4.91-5.20 (m, CFCH, 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15-3.40 (m, CH, 2H), 3.95-4.20 (m, COOCH2CH2, 2H), 2.65 (m, CH2 (lactone), 1H), 2.30-2.45 (m, COOCH2CH2, 1H), 2.25 (m, CH2 (lactone), 1H), 2.05 (m, COOCH2CH2, 1H)

Compound (B0-26): Combination of procatalyst (Bpre-26) and salt exchange compound A ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.99 (d, Ar-I, 1H), 7.74-7.90 (m, ArH+Ar-I, 16H), 7.01-7.47 (m, ArH, 8H), 5.39 (m, CH (lactone), 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H) 4.41 (m, CH2 (lactone), 1H), 4.05-4.25 (m, COOCH2CH2+ CH2 (lactone), 3H), 3.15-3.40 (m, CH, 2H), 2.63-2.73 (m, COOCH2CH2+CH2 (lactone), 3H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-27): Combination of precursor (Bpre-20) and salt exchange compound B ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 7.70-8.22 (m, ArH+Ar-I, 16H), 7.01-7.47 (m, ArH, 8H), 5.39 (m, CH (lactone), 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15-3.45 (m, SO2CH+CH, 3H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H), 1.09-1.90 (m, cyclohexyl, 10H)

Compound (B0-28): Combination of precursor (Bpre-20) and salt exchange compound C ¹ H-NMR (DMSO, 400MHz): δ(ppm)=7.77-7.99 (m, ArH+Ar-I, 13H), 7.01-7.47(m, ArH, 8H), 5.39 (m, CH (lactone), 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15-3.40 (m, CH, 2H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

Compound (B0-29): Combination of procatalyst (Bpre-20) and salt exchange compound D ¹ H-NMR (DMSO, 400MHz): δ (ppm) = 8.50 (d, ArH, 2H), 8.37 (d, ArH, 2H), 7.99 (m, Ar-I, 1H), 7.93 (t, ArH, 2H), 7.84 (d, Ar-I, 1H), 7.55-7.75 (m, ArH, 7H), 7.01-7.47 (m, ArH, 8H), 5.39 (m, CH (lactone), 1H), 4.70-4.85 (m, -OCO-CH-CH-COO-, 2H), 4.51-4.68 (m, CF2CH2, 2H), 4.41 (m, CH2 (lactone), 1H), 4.25 (m, CH2 (lactone), 1H), 3.15-3.40 (m, CH, 2H), 2.65 (m, CH2 (lactone), 1H), 2.25 (m, CH2 (lactone), 1H)

<Preparation of Resistant Composition> (Examples 1 to 33, Comparative Examples 1 to 4) The respective components shown in Tables 1 to 5 are mixed and dissolved to prepare the respective resist compositions.

In Tables 1 to 5, each abbreviation has the following meaning. The values in [ ] are the compounding amounts (parts by mass). (A)-1: A polymer compound represented by the following chemical formula (A1-1). For the polymer compound (A1-1), the weight average molecular weight (Mw) converted to standard polystyrene obtained by GPC measurement is 5800, and the molecular weight dispersion (Mw/Mn) is 1.54. The copolymer composition ratio (the ratio of each constituent unit in the structural formula (molar ratio)) obtained by ¹³ C-NMR is l/m=50/50. (A)-2: A polymer compound represented by the following chemical formula (A1-2). For the polymer compound (A1-2), the weight average molecular weight (Mw) converted to standard polystyrene obtained by GPC measurement is 6000, and the molecular weight dispersion (Mw/Mn) is 1.55. The copolymer composition ratio (the ratio of each constituent unit in the structural formula (molar ratio)) determined by ¹³ C-NMR is l/m=50/50. (A)-3: A polymer compound represented by the following chemical formula (A1-3). The weight average molecular weight (Mw) of the polymer compound (A1-3) determined by GPC measurement was 5900 in terms of standard polystyrene, and the molecular weight dispersion (Mw/Mn) was 1.54. The copolymer composition ratio (the ratio of each constituent unit in the structural formula (molar ratio)) determined by ¹³ C-NMR is l/m=50/50.

(B)-31: Acid generator formed from the following compound (B1-1). (B)-32: Acid generator formed from the following compound (B1-2). (B)-33: Acid generator formed from the following compound (B1-3). (B)-34: Acid generator formed from the following compound (B1-4). (B)-1 to (B)-29: Compounds (B0-1) to (B0-29) above.

(D)-1: Acid diffusion control agent composed of the following compound (D1-1).

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

<Formation of Resist Pattern> On an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS), the resist composition of each example was applied using a spinner, and a preheating (PAB) treatment was performed on a hot plate at a temperature of 110°C for 60 seconds, and a resist film with a film thickness of 50nm was formed by drying. Next, for the above-mentioned resist film, an electron beam drawing device JEOL-JBX-9300FS (manufactured by JEOL Ltd.) was used to draw (expose) a contact hole pattern (hereinafter referred to as "CH pattern") in which holes with a diameter of 32nm were arranged at equal intervals (pitch 64nm) at an accelerating voltage of 100Kv. Thereafter, a post-exposure heating (PEB) treatment was performed at 100°C for 60 seconds. Next, alkaline development was performed at 23°C for 60 seconds using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Industry Co., Ltd.). Thereafter, pure water was used for 15 seconds of water rinsing. As a result, a CH pattern was formed in which holes with a diameter of 32nm were arranged at equal intervals (spacing 64nm).

[Evaluation of Sensitivity] The optimum exposure Eop (μC/cm ^{2 ) for forming a CH pattern of a target scale was obtained through the above <Formation of Resist Pattern>. The results are shown in Tables 6-7 as "Eop (μC/cm 2 )} ".

[Evaluation of in-plane uniformity of pattern size (CDU)] For the CH pattern formed by the above <Formation of resist pattern>, the CH pattern was observed from the top by length measurement SEM (scanning electron microscope, accelerating voltage 500V, trade name: CG5000, manufactured by Hitachi High Technologies Co., Ltd.), and the pore diameter (nm) of each pore was measured. Then, the 3 times value (3σ) of the calculated standard deviation (σ) was obtained from the measurement result. The result is expressed as "CDU (nm)" in Tables 6 to 7. The smaller the value of 3σ obtained in this way, the higher the uniformity of the size (CD) of the multiple pores formed in the resist film.

[Evaluation of Ultimate Resolution] The ultimate resolution at the optimal exposure (Eop) of the CH pattern formed by the above <Formation of Resist Pattern> is specifically obtained by using a scanning electron microscope (trade name: S-9380, manufactured by Hitachi High Technologies Co., Ltd.) to obtain the aperture diameter (nm) of the resolved pattern when the CH pattern is formed by gradually reducing the exposure from the optimal exposure (Eop). The results are shown in Tables 6 to 7 as "Ultimate Resolution (nm)".

From the results shown in Tables 6 to 7, it can be confirmed that by comparing Examples 1 to 33 with Comparative Examples 1 to 4, the use of the resist compositions of Examples 1 to 33 of the present invention can achieve the effects of high sensitivity and in-plane uniformity (CDU) of pattern size and fine resolution. In addition, when the resist compositions of Examples 1 to 33 are compared with the resist compositions of Comparative Examples 1 to 4, it is confirmed that the CDU and fine resolution of the resist compositions of Examples 1 to 33 are both high.

The above describes the preferred embodiments of the present invention, but the present invention is not limited to these embodiments. Additions, omissions, substitutions and other changes can be made without departing from the scope of the present invention. The present invention is not limited to the above description, but is limited to the scope of the patent application recorded.

Claims (8)

A resist composition that generates acid by exposure and changes its solubility in a developer by the action of the acid, wherein the resist composition comprises a base component (A) whose solubility in a developer changes by the action of the acid, and a compound (B0) represented by the following general formula (b0), [In the formula, ^Rb is an alkali-decomposable group; ^L03 is a divalent linking group; ^Rl0 is a cyclic organic group which may have a substituent; ^L02 is a divalent linking group; I is an iodine atom; ^Rm1 is a substituent other than an iodine atom; ^L01 is a divalent linking group or a single bond; ^Vb0 is an alkylene group, a fluorinated alkylene group or a single bond; however, ^L01 and ^Vb0 will not simultaneously form a single bond; ^R0 is a fluorinated alkylene group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom; nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3; however, 2≦nb1+nb2+nb3≦5; Mm ⁺ represents an m-valent organic cation; m is an integer greater than 1]. The inhibitor composition of claim 1, wherein R ^b in the aforementioned general formula (b0) has a cyclic group containing a lactone. The inhibitor composition of claim 1 or 2, wherein -L ⁰¹ -Vb ⁰ - in the aforementioned general formula (b0) is a linking group represented by any one of the following general formulas (b0-r-1) to (b0-r-7), [In the formula, L ⁰¹¹ is an alkylene group having 1 to 5 carbon atoms or a single bond; L ⁰¹² is a divalent saturated alkyl group having 1 to 30 carbon atoms or a single bond; Vb ⁰¹ is a fluorinated alkylene group having 1 to 4 carbon atoms or a single bond; however, L ⁰¹² and Vb ⁰¹ will not be a single bond at the same time]. A method for forming a resist pattern comprises the steps of forming a resist film on a support using a resist composition as claimed in claim 1 or 2, exposing the resist film, and developing the exposed resist film to form a resist pattern. A compound represented by the following general formula (b0), [In the formula, ^Rb is an alkali-decomposable group; ^L03 is a divalent linking group; ^Rl0 is a cyclic organic group which may have a substituent; ^L02 is a divalent linking group; I is an iodine atom; ^Rm1 is a substituent other than an iodine atom; ^L01 is a divalent linking group or a single bond; ^Vb0 is an alkylene group, a fluorinated alkylene group or a single bond; however, ^L01 and ^Vb0 will not simultaneously form a single bond; ^R0 is a fluorinated alkylene group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom; nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3; however, 2≦nb1+nb2+nb3≦5; Mm ⁺ represents an m-valent organic cation; m is an integer greater than 1]. The compound of claim 5, wherein R ^b in the aforementioned general formula (b0) is a group having a cyclic group containing a lactone. The compound of claim 5 or 6, wherein -L ⁰¹ -Vb ⁰ - in the aforementioned general formula (b0) is a linking group represented by any one of the following general formulas (b0-r-1) to (b0-r-7), [In the formula, L ⁰¹¹ is an alkylene group having 1 to 5 carbon atoms or a single bond; L ⁰¹² is a divalent saturated alkyl group having 1 to 30 carbon atoms or a single bond; Vb ⁰¹ is a fluorinated alkylene group having 1 to 4 carbon atoms or a single bond; however, L ⁰¹² and Vb ⁰¹ will not be a single bond at the same time]. An acid generator comprising the compound of claim 5 or 6.