WO2024053718A1

WO2024053718A1 - Resist composition, method for forming resist pattern, compound, and polymer compound

Info

Publication number: WO2024053718A1
Application number: PCT/JP2023/032751
Authority: WO
Inventors: 広樹加藤
Original assignee: 東京応化工業株式会社
Priority date: 2022-09-08
Filing date: 2023-09-07
Publication date: 2024-03-14
Also published as: JP2024038872A

Abstract

The present invention employs a resist composition that contains a resin component having a constituent unit represented by general formula (a0-1). In formula (a0-1), R⁰¹ is a divalent linking group or a single bond. R⁰² is an acid-dissociable group. Y⁰⁰ is a divalent linking group or single bond. R⁰⁰ is an aromatic hydrocarbon group that may have a substituent. Y⁰¹ is a single bond or a divalent linking group that contains an oxygen atom. V⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. R⁰³ is a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. M^m+ is an m-valent onium cation. m is an integer of 1 or more. The resist composition has high sensitivity at the time of formation of a resist pattern, and has good lithographic characteristics.

Description

Resist composition, resist pattern forming method, compound and polymer compound

The present invention relates to a resist composition, a resist pattern forming method, a compound, and a polymer compound.
This application claims priority based on Japanese Patent Application No. 2022-143204, filed in Japan on September 8, 2022, the contents of which are incorporated herein.

In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, advances in lithography technology have led to rapid miniaturization of patterns. As a technique for miniaturization, generally the wavelength of the exposure light source is shortened (higher energy).
Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with minute dimensions.
As a resist material that satisfies these requirements, chemically amplified resist compositions have conventionally been used that contain a base component whose solubility in a developer changes due to the action of an acid, and an acid generator component that generates an acid upon exposure. is used.

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

Furthermore, in chemically amplified resist compositions, a polymer compound into which a structural unit containing an acid generating group that generates an acid upon exposure has been introduced as an acid generator component has been proposed (see, for example, Patent Document 1). Such a polymer compound has both the function of an acid generator and the function of a base material component.

Japanese Patent Application Publication No. 2014-153440

With further progress in lithography technology and expansion of application fields, patterns are rapidly becoming finer. Accordingly, when manufacturing semiconductor devices and the like, there is a need for technology that can form patterns with fine dimensions and good shapes. Therefore, resist compositions are required to have even higher sensitivity and further improve lithography properties such as pattern size uniformity.
The present invention has been made in view of the above circumstances, and provides a resist composition that achieves high sensitivity and has good lithography properties, a method for forming a resist pattern using the resist composition, and a resist composition useful for the resist composition. An object of the present invention is to provide a polymer compound and a compound that can be used to synthesize the polymer compound.

In order to solve the above problems, the present invention employs the following configuration.
That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure to light and whose solubility in a developing solution changes due to the action of the acid. This is a resist composition characterized in that the resin component (A1) has a structural unit (a0) represented by the following general formula (a0-1).

[In the formula, R ⁰¹ is a divalent linking group or a single bond. R ⁰² is an acid dissociable group. Y ⁰⁰ is a divalent linking group or a single bond. R ⁰⁰ is an aromatic hydrocarbon group which may have a substituent. Y ⁰¹ is a divalent linking group or a single bond containing an oxygen atom. V ⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. R ⁰³ is a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. M ^m+ is an m-valent onium cation. m is an integer of 1 or more. Y ⁰¹ and V ⁰¹ never become a single bond at the same time. ]

A second aspect of the present invention includes a step of forming a resist film on a support using the resist composition according to the first aspect, a step of exposing the resist film, and a step of exposing the resist film to light after the exposure. This is a resist pattern forming method characterized by having a step of developing and forming a resist pattern.

A third aspect of the present invention is a compound characterized by being represented by the following general formula (a0-m1).

A fourth aspect of the present invention is a polymer compound characterized by having a structural unit represented by the following general formula (a0-1).

According to the present invention, a resist composition capable of achieving high sensitivity and having good lithography properties, a resist pattern forming method using the resist composition, a polymer compound useful for the resist composition, and the polymer compound can provide compounds that can be used for the synthesis of

In this specification and the claims, the term "aliphatic" is a relative concept to aromatic, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the "alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups.
Examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
"Constituent unit" means a monomer unit (monomer unit) that constitutes a high molecular compound (resin, polymer, copolymer).
When describing "may have a substituent", there are cases in which a hydrogen atom (-H) is substituted with a monovalent group and a case in which a methylene group (-CH ₂ -) is substituted with a divalent group. including both.
“Exposure” is a concept that includes radiation irradiation in general.

An "acid-decomposable group" is a group having acid-decomposability that allows at least a portion of the bonds in the structure of the acid-decomposable group to be cleaved by the action of an acid.
Examples of acid-decomposable groups whose polarity increases due to the action of an acid include groups that decompose under the action of an acid to produce a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO ₃ H).
More specifically, the acid-decomposable group includes a group in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

"Acid-dissociable group" means (i) a group having acid-dissociable properties that allows the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group to be cleaved by the action of an acid; (ii) A group in which the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved by further decarboxylation reaction after some bonds are cleaved by the action of an acid. , refers to both.
The acid-dissociable group constituting the acid-dissociable group needs to be a group with lower polarity than the polar group generated by dissociation of the acid-dissociable group. When is dissociated, a polar group having higher polarity than the acid-dissociable group is generated and the polarity increases. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the relative solubility in the developer changes; when the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases. Decrease.

The "base material component" is an organic compound that has film-forming ability. Organic compounds used as base material components are broadly classified into non-polymers and polymers. As the non-polymer, those having a molecular weight of 500 or more and less than 4,000 are usually used (hereinafter referred to as "low-molecular compound"). Hereinafter, "resin", "high molecular compound", or "polymer" refers to a polymer having a molecular weight of 1000 or more. As the molecular weight of the polymer, the weight average molecular weight calculated by GPC (gel permeation chromatography) in terms of polystyrene is used.

"Derived structural unit" means a structural unit formed by cleavage of multiple bonds between carbon atoms, for example, ethylenic double bonds.
In the "acrylic ester", the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. The substituent (R ^αx ) that substitutes the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom. In addition, there are also itaconic acid diesters in which the substituent (R ^αx ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R ^αx ) is substituted with a hydroxyalkyl group or a group modifying the hydroxyl group. shall be included. Note that the carbon atom at the α-position of the acrylic ester is the carbon atom to which the carbonyl group of acrylic acid is bonded, unless otherwise specified.
Hereinafter, an acrylic ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylic ester.

The term "derivative" is a concept that includes target compounds in which the hydrogen atom at the α-position is substituted with other substituents such as alkyl groups and halogenated alkyl groups, as well as derivatives thereof. These derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound is replaced with an organic group; the hydrogen atom at the α position may be substituted with a substituent; Good target compounds include those to which a substituent other than a hydroxyl group is bonded. Note that the α position refers to the first carbon atom adjacent to a functional group, unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include those similar to R ^αx , such as an alkyl group and a halogenated alkyl group.

In this specification and the claims, some structures represented by chemical formulas may contain asymmetric carbon atoms, and enantiomers or diastereomers may exist. In that case, one chemical formula represents these isomers. These isomers may be used alone or as a mixture.

(Resist composition)
The resist composition of this embodiment generates acid upon exposure, and its solubility in a developer changes due to the action of the acid.
Such a resist composition contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of an acid. In the resist composition of this embodiment, the component (A) includes a resin component that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid.

When a resist film is formed using the resist composition of the present embodiment and the resist film is selectively exposed to light, an acid is generated from the component (A) in the exposed portion of the resist film. As a result, the solubility of component (A) in the developing solution changes, while the solubility of component (A) in the developing solution does not change in the unexposed area of the resist film, so that the solubility of the component (A) in the developing solution does not change. There is a difference in solubility in the developing solution between the unexposed area and the unexposed area. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed portion of the resist film is dissolved and removed to form a positive resist pattern, and if the resist composition is negative type, the resist pattern is The unexposed portions of the film are dissolved and removed to form a negative resist pattern.

The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Further, the resist composition of the present embodiment may be used in an alkaline development process using an alkaline developer in the development process during resist pattern formation, and in the development process, a developer containing an organic solvent (organic developer) may be used. It may also be used for a solvent development process using a liquid).

<Base material component (A)>
In the resist composition of the present embodiment, component (A) includes a resin component (A1) whose solubility in a developer changes due to the action of an acid (hereinafter also referred to as "component (A1)").
By using the component (A1), the polarity of the base material component changes before and after exposure, so that good development contrast can be obtained not only in an alkaline development process but also in a solvent development process.
As component (A), at least one of another high molecular compound and a low molecular compound may be used together with the component (A1).
In the resist composition of the present embodiment, one kind of component (A) may be used alone, or two or more kinds may be used in combination.

- Regarding the resin component (A1) The component (A1) is a resin component whose solubility in a developer changes due to the action of an acid. Component (A1) has a structural unit (a0) represented by the general formula (a0-1) described below.
In addition to the structural unit (a0), the component (A1) may have other structural units as necessary.

≪Constituent unit (a0)≫
The structural unit (a0) is a structural unit represented by the following general formula (a0-1). The structural unit (a0) contains an acid-decomposable group (R ⁰² -O-C(=O)-) whose polarity increases by the action of an acid.

In the formula (a0-1), R ⁰¹ is a divalent linking group or a single bond.
Examples of the divalent linking group for R ⁰¹ include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

When R ⁰¹ is a divalent hydrocarbon group which may have a substituent, the divalent hydrocarbon group is preferably a linear or branched aliphatic hydrocarbon group. The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and has 1 to 4 carbon atoms. 3 is particularly preferred. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, particularly 3 carbon atoms. preferable. The linear or branched hydrocarbon group may be saturated or unsaturated, but saturated is preferred.

When R ⁰¹ is a divalent linking group containing a hetero atom, the linking group is preferably -O-, -C(=O)-O-, -O-C(=O)-, - C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H is an alkyl group, an acyl group ), -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, general formula -Y ²¹ -O-Y ²² -, - Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-O-Y ²¹ -, -[Y ²¹ -C(=O)-O] _m” -Y ²² A group represented by -, -Y ²¹ -O-C(=O)-Y ²² - or -Y ²¹ -S(=O) ₂ -O-Y ²² - [wherein Y ²¹ and Y ²² are each It is a divalent hydrocarbon group which may independently have a substituent, O is an oxygen atom, and m'' is an integer from 0 to 3. ] etc.
The divalent linking group containing the heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH) In the case of -, H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
General formula -Y ²¹ -O-Y ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-O-Y ²¹ -, -[Y ²¹ - C(=O)-O] _m” -Y ²² -, -Y ²¹ -O-C(=O)-Y ²² - or -Y ²¹ -S(=O) ₂ -O-Y ²² -, Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include those mentioned above.
^Y21 is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, even more preferably a linear alkylene group having 1 to 5 carbon atoms, and a methylene group or an ethylene group. Particularly preferred.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula -[Y ²¹ -C(=O)-O] _m" -Y ²² -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, and 0 or 1 is more preferred, and 1 is particularly preferred. In other words, the group represented by the formula -[Y ²¹ -C(=O)-O] _m" -Y ²² - is the group represented by the formula -Y ²¹ -C(=O)-O-Y ²² - Groups are particularly preferred. Among these, groups represented by the formula -(CH ₂ ) _a' -C(=O)-O-(CH ₂ ) _b' - are preferred. In the formula, a' is 1 to is an integer of 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, and An integer of 1 to 5 is preferred, an integer of 1 to 5 is more preferred, 1 or 2 is even more preferred, and 1 is most preferred.

The divalent linking group in R ⁰¹ is preferably a divalent linking group containing a hetero atom, and (main chain side) -C(=O)-O-Y ²¹ - is more preferred.

R ⁰¹ is preferably a divalent linking group containing a hetero atom or a single bond.

In the formula (a0-1), R ⁰² is an acid dissociable group.
Examples of the acid-dissociable group in R ⁰² include those that have been proposed as acid-dissociable groups for base resins for chemically amplified resist compositions.
Specifically, examples of acid-dissociable groups proposed as acid-dissociable groups for base resins for chemically amplified resist compositions include "acetal-type acid-dissociable groups" and "tertiary alkyl ester-type acid-dissociable groups" described below. "group" and "secondary alkyl ester type acid dissociable group". These acid-dissociable groups protect -O-C(=O)- in the acid-decomposable group (R ⁰² -O-C(=O)-) in the structural unit (a0), and are Dissociates from acid-decomposable groups. This produces a carboxy group (HO-C(=O)-).

Acetal type acid dissociable group:
Examples of the acetal-type acid-dissociable group in R ⁰² include acid-dissociable groups represented by the following general formula (a1-r-1).

[In the formula, Ra' ¹ and Ra' ² are each a hydrogen atom or an alkyl group. Ra' ³ is a hydrocarbon group, and Ra' ³ may be bonded to 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 more preferably both are hydrogen atoms.
When Ra' ¹ or Ra' ² is an alkyl group, the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. Specifically, linear or branched alkyl groups are preferably mentioned. More specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. More preferred, and methyl group is particularly preferred.

In formula (a1-r-1), the hydrocarbon group for Ra' ³ includes a linear or branched alkyl group, or a cyclic hydrocarbon group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, and the like. Among these, methyl group, ethyl group or n-butyl group are preferred, and methyl group or ethyl group is more preferred.

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

When Ra' ³ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms. Examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

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

The cyclic hydrocarbon group at Ra' ³ may have a substituent. Examples of this substituent include -R ^P1 , -R ^P2 -O-R ^P1 , -R ^P2 -CO-R P1 , -R ^P2 -CO- ^{OR P1} ^, -R ^P2 -O-CO-R ^P1 , -R ^P2 -OH, -R ^P2 -CN or -R ^P2 -COOH (hereinafter these substituents are also collectively referred to as "Ra ^x5 "), and the like.
Here, R ^P1 is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent cyclic saturated hydrocarbon group having 6 to 30 carbon atoms. It is a monovalent aromatic hydrocarbon group. R ^P2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a group having 6 to 20 carbon atoms. 30 divalent aromatic hydrocarbon groups. However, some or all of the hydrogen atoms of the chain saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group of R ^P1 and R ^P2 may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the above substituents, or may have one or more of each of the above substituents.
Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, etc. It will be done.
Examples of the monovalent aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group, etc. Monocyclic aliphatic saturated hydrocarbon group; bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl Examples include polycyclic aliphatic saturated hydrocarbon groups such as a group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group.
Examples of monovalent aromatic hydrocarbon groups 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 combined with 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 a tetrahydropyranyl group, a tetrahydrofuranyl group, and the like.

Tertiary alkyl ester type acid dissociable group:
Examples of the tertiary alkyl ester type acid-dissociable group in R ⁰² include acid-dissociable groups represented by the following general formula (a1-r-2).

[In the formula, Ra' ⁴ to Ra' ⁶ are each a hydrocarbon group, and Ra' ⁵ and Ra' ⁶ may be bonded to each other to form a ring. * represents a bond with the oxygen atom bonded to R ⁰² in the general formula (a0-1). ]

In the above formula (a1-r-2), the hydrocarbon group for Ra' ⁴ includes a linear or branched alkyl group, a chain or cyclic alkenyl group, or a cyclic hydrocarbon group. .
Straight chain or branched alkyl group, cyclic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group, aromatic hydrocarbon group) in Ra' ⁴ ) is the same as Ra' ³ above.
The chain or cyclic alkenyl group for Ra' ⁴ is preferably an alkenyl group having 2 to 10 carbon atoms.
Examples of the hydrocarbon groups for Ra' ⁵ and Ra' ⁶ include the same ones as for Ra' ³ above.

When Ra' ⁵ and Ra' ⁶ combine with each other to form a ring, a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2) , groups represented by the following general formula (a1-r2-3) are preferably mentioned.
On the other hand, when Ra' ⁴ to Ra' ⁶ do not bond to each other and are independent hydrocarbon groups, groups represented by the following general formula (a1-r2-4) are preferred.

[In 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 heteroatom-containing group; shows. Ra' ¹¹ represents a group forming an aliphatic cyclic group together with the carbon atom to which Ra' ¹⁰ is bonded.
In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms possessed by this 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; be. Some or all of the hydrogen atoms possessed by the chain saturated hydrocarbon group and aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra ¹⁰¹ to Ra ¹⁰³ may be bonded to each other to form a cyclic structure.
In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra ¹⁰⁴ is an aromatic hydrocarbon group which may have a substituent.
In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms possessed by this chain saturated hydrocarbon group may be substituted. Ra' ¹⁴ is a hydrocarbon group which may have a substituent. * indicates a bond (the same applies hereinafter). ]

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 heteroatom-containing group. It is the basis.

The linear alkyl group in Ra' ¹⁰ has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and further preferably 1 to 3 carbon atoms. Preferred are methyl and ethyl groups, particularly preferred.
Examples of the branched alkyl group in Ra' ¹⁰ include the same ones as in Ra' ³ above.

The alkyl group at Ra' ¹⁰ may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Moreover, some of the carbon atoms (methylene group, etc.) constituting the alkyl group may be substituted with a heteroatom-containing group.
Examples of the heteroatom here include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)- Examples include O-, -C(=O)-NH-, -NH-, -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, and the like.

In formula (a1-r2-1), Ra' ¹¹ (the aliphatic cyclic group formed together with the carbon atom to which Ra' ¹⁰ is bonded) is the monocyclic group of Ra' ³ in formula (a1-r-1). Or the group mentioned as an aliphatic hydrocarbon group (alicyclic hydrocarbon group) which is a polycyclic group is preferable. Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl groups and cyclohexyl groups are more preferred. Alternatively, Ra' ¹¹ (the aliphatic cyclic group formed together with the carbon atom to which Ra' ¹⁰ is bonded) may be unsaturated, and specifically, a cyclopentenyl group and a cyclohexenyl group are preferable.
Ra' ¹¹ (the aliphatic cyclic group formed with the carbon atom to which Ra' ¹⁰ is bonded) may have a substituent, such as an iodine atom, a bromine atom, a fluorine atom, an alkoxy Examples include groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.).

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

In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya is a cyclic ^monovalent hydrocarbon group (aliphatic Examples include groups obtained by further removing one or more hydrogen atoms from a hydrocarbon group.
The cyclic hydrocarbon group formed by Xa and Ya may have a substituent. Examples of this substituent include those similar to the substituents that the cyclic hydrocarbon group in Ra' ³ above may have.
In formula (a1-r2-2), the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra ¹⁰¹ to Ra ¹⁰³ includes, for example, a methyl group, an ethyl group, a propyl group, a butyl group, Examples include pentyl group, hexyl group, heptyl group, octyl group, and decyl group.
Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in Ra ¹⁰¹ to Ra ¹⁰³ include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, Monocyclic aliphatic saturated hydrocarbon groups such as cyclodecyl group and cyclododecyl group; bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3. 1.13,7]decanyl group, tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and polycyclic aliphatic saturated hydrocarbon groups such as adamantyl group.
From the viewpoint of ease of synthesis, Ra ¹⁰¹ to Ra ¹⁰³ are preferably a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, and among these, a hydrogen atom, a methyl group, or an ethyl group is preferable. More preferred is a hydrogen atom, particularly preferred.

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

Groups containing a carbon-carbon double bond formed by two or more of Ra ¹⁰¹ to Ra ¹⁰³ bonding to each other to form a cyclic structure include, for example, a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methyl Examples include a cyclohexenyl group, a cyclopentylideneethenyl group, and a cyclohexylideneethenyl group. Among these, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylideneethenyl group are preferred from the viewpoint of ease of synthesis.

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

In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is a carbonized aliphatic group that is a monocyclic group or polycyclic group of Ra' ³ in formula (a1-r-1). The groups listed as hydrogen groups are preferred.
In formula (a1-r2-3), the aromatic hydrocarbon group for Ra ¹⁰⁴ includes a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among these, Ra ¹⁰⁴ is preferably a group in which one or more hydrogen atoms are removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, and more preferably a group in which one or more hydrogen atoms are removed from benzene, naphthalene, anthracene, or phenanthrene. Preferably, a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene is more preferable, a group obtained by removing one or more hydrogen atoms from benzene or naphthalene is particularly preferable, and a group obtained by removing one or more hydrogen atoms from benzene is more preferable. Most preferred.

Examples of substituents that Ra ¹⁰⁴ in formula (a1-r2-3) may have include methyl group, ethyl group, propyl group, hydroxy group, carboxy group, halogen atom, alkoxy group (methoxy group, (ethoxy group, propoxy group, butoxy group, etc.), alkyloxycarbonyl group, etc.

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

In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. As the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra' ¹² and Ra' ¹³ , the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in the above Ra ¹⁰¹ to Ra ¹⁰³ can be used. Examples include those similar to hydrocarbon groups. Some or all of the hydrogen atoms possessed by this chain saturated hydrocarbon group may be substituted.
Among them, Ra' ¹² and Ra' ¹³ are preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group. .
When the chain saturated hydrocarbon group represented by Ra' ¹² and Ra' ¹³ is substituted, examples of the substituent include the same groups as Ra ^x5 described above.

In formula (a1-r2-4), Ra' ¹⁴ is a hydrocarbon group that may have a substituent. The hydrocarbon group for Ra' ¹⁴ includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

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

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

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

Examples of the aromatic hydrocarbon group in Ra' ¹⁴ include those similar to the aromatic hydrocarbon group in Ra ¹⁰⁴ . Among these, 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, and 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 is even more preferable, a group obtained by removing one or more hydrogen atoms from benzene or naphthalene is particularly preferable, a group obtained by removing one or more hydrogen atoms from benzene is most preferred.
Examples of the substituents that Ra' ¹⁴ may have include the same substituents as those that Ra ¹⁰⁴ may have. The substituent that Ra' ¹⁴ may have is preferably a methyl group, ethyl group, propyl group, iodine atom, bromine atom, fluorine atom, alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.) ) etc.

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

Secondary alkyl ester type acid dissociable group:
Examples of the secondary alkyl ester type acid-dissociable group in R ⁰² include acid-dissociable groups represented by the following general formula (a1-r-4).

[In the formula, Ra' ¹⁰ is a hydrocarbon 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 hydrocarbon group. Ra' ¹⁰ and Ra' ^11a or Ra' ^11b may be bonded to each other to form a ring. Ra' ^11a or Ra' ^11b and Ra' ¹² may be bonded to each other to form a ring. * represents a bond with the oxygen atom bonded to R ⁰² in the general formula (a0-1). ]

In the above formula (a1-r-4), examples of the hydrocarbon groups at Ra' ¹⁰ and Ra' ¹² include those similar to those for Ra' ³ above.
In the formula, the alkyl groups for Ra' ^11a and Ra' ^11b include the same alkyl groups as for Ra' ¹ above. The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. Specifically, linear or branched alkyl groups are preferably mentioned. More specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. More preferred, and methyl group is particularly preferred.
In the formula, the hydrocarbon group at Ra' ¹⁰ and Ra' ¹² and the alkyl group at Ra' ^11a and Ra' ^11b may have a substituent. Examples of this substituent include the above-mentioned Ra ^x5 .

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

The ring formed by bonding Ra' ¹⁰ and Ra' ^11a or Ra' ^11b to each other is a monocycloalkene, a monocycloalkene in which some of the carbon atoms are heteroatoms (oxygen atom, sulfur atom, etc.). etc.), monocycloalkadienes are preferred, cycloalkenes having 3 to 6 carbon atoms are preferred, and cyclopentene or cyclohexene is preferred.

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

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

Ra' ^11a or Ra' ^11b and Ra' ¹² may be bonded to each other to form a ring, and as the ring, Ra' ¹⁰ and Ra' ^11a or Ra' ^11b may be bonded to each other to form a ring. Examples include those similar to the rings that are formed.

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

Among the above, as the acid dissociable group in R ⁰² , a tertiary alkyl ester type acid dissociable group and a secondary alkyl ester type acid dissociable group are preferable, and the acid dissociable group in the above general formula (a1-r2-1) is preferable. group represented by general formula (a1-r2-2), group represented by general formula (a1-r2-4), acid dissociation represented by general formula (a1-r-4) A group represented by the general formula (a1-r2-1) is even more preferable.

In the formula (a0-1), Y ⁰⁰ is a divalent linking group or a single bond.
Examples of the divalent linking group in Y ⁰⁰ include those similar to the divalent linking group in R ⁰¹ above. Among these, the divalent linking group in Y ⁰⁰ is preferably a divalent linking group containing a hetero atom, and (main chain side) -Y ²¹ -O- (R ⁰⁰ side) is more preferable.
This Y ²¹ is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, even more preferably a linear alkylene group having 1 to 5 carbon atoms, and a methylene group or an ethylene group. is particularly preferred.
Y ⁰⁰ is preferably a divalent linking group, more preferably a divalent linking group containing a hetero atom.

In the formula (a0-1), R ⁰⁰ is an aromatic hydrocarbon group which may have a substituent.
The aromatic hydrocarbon group in R ⁰⁰ is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituents.
Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene.

Specifically, the aromatic hydrocarbon group in R ⁰⁰ includes a group obtained by removing two hydrogen atoms from an aromatic hydrocarbon ring (arylene group); an aromatic compound containing two or more aromatic hydrocarbon rings (for example, biphenyl, Examples include groups obtained by removing two hydrogen atoms from (such as fluorene).

The aromatic hydrocarbon group may or may not have a substituent. The substituent here is a substituent that substitutes a hydrogen atom possessed by an aromatic hydrocarbon group. For example, the hydrogen atom bonded to the aromatic hydrocarbon ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group. , methoxy group, and ethoxy group are more preferred.
The halogen atom as the substituent is preferably an iodine atom, a bromine atom, or a fluorine atom.
Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms.

Among the above, R ⁰⁰ in the general formula (a0-1) is preferably an aromatic hydrocarbon group having a substituent from the viewpoint of achieving both high sensitivity and lithography properties.
The substituent of the aromatic hydrocarbon group in R ⁰⁰ is preferably one or more selected from the group consisting of a halogen atom, an alkyl group, and an alkoxy group, from the viewpoint of high sensitivity, and among these, a halogen atom More preferably, it is one or more selected from the group consisting of an iodine atom, a bromine atom, and a fluorine atom, and an iodine atom is particularly preferable.

Among the above, R ⁰⁰ in the general formula (a0-1) is preferably a group represented by the following general formula (R ⁰⁰ -1).

[In the formula, R ^a1 and R ^a2 each independently represent a halogen atom, an alkyl group, or an alkoxy group. m0 is an integer from 0 to 2. 0≦n1≦m0×2+2. 0≦n2≦4. 0≦n1+n2≦m0×2+4. Either *11 or *12 represents a bond with Y ⁰⁰ in the general formula (a0-1). Either *21 or *22 represents a bond with Y ⁰¹ in the general formula (a0-1). ]

In the formula (R ⁰⁰ -1), R ^a1 and R ^a2 each independently represent a halogen atom, an alkyl group, or an alkoxy group.
The halogen atom, alkyl group, and alkoxy group in R ^a1 and R ^a2 are the same as the halogen atom, alkyl group, and alkoxy group exemplified in the explanation of the substituent of the aromatic hydrocarbon group in R ⁰⁰ mentioned above. , preferably a halogen atom.
In the formula (R ⁰⁰ -1), m0 is preferably 0 or 1, more preferably 0.
In the formula (R ⁰⁰ -1), n2 is preferably 1 or 2, more preferably 2.

In the formula (a0-1), Y ⁰¹ is a divalent linking group or a single bond containing an oxygen atom.
When Y ⁰¹ is a divalent linking group containing an oxygen atom, Y ⁰¹ may contain atoms other than the oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.
Examples of divalent linking groups containing an oxygen atom include an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), and an oxycarbonyl group (-O-C(=O-). )-), amide bond (-C(=O)-NH-), carbonyl group (-C(=O)-), carbonate bond (-O-C(=O)-O-), etc. Oxygen atom-containing connecting group; a combination of the non-hydrocarbon oxygen atom-containing connecting group and an alkylene group, and the like. A sulfonyl group (-SO ₂ -) may be further linked to this combination.
Examples of such divalent linking groups containing an oxygen atom include linking groups represented by the following general formulas (y-al-1) to (y-al-8), respectively.
In addition, in the following general formulas (y-al-1) to (y-al-8), the bond to R ⁰⁰ in the above formula (a0-1) is the following general formula (y-al-1) to It is V' ¹⁰¹ in (y-al-8).

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

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

The alkylene group in V' ¹⁰¹ and V' ¹⁰² may be a linear alkylene group or a branched alkylene group, with a linear alkylene group being preferred.
Specifically, the alkylene group in V' ¹⁰¹ and V' ¹⁰² is a methylene group [-CH ₂ -]; -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 -, etc. alkylmethylene groups; ethylene; Group [-CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ ) Alkylethylene group such as CH ₂ -; trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH ₂ -]; -CH (CH ₃ ) CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ ) Alkyltrimethylene group such as CH ₂ -; tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -]; -CH (CH ₃ ) CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ ) CH ₂ Examples include alkyltetramethylene groups such as CH ₂ -; pentamethylene groups [-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -], and the like.
Further, a part of the methylene group in the alkylene group in V' ¹⁰¹ or V' ¹⁰² may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is a divalent group obtained by removing one hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group). Preferably, a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferable.

Y ⁰¹ is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, each represented by the above formulas (y-al-1) to (y-al-6). A linking group is more preferred, and a linking group represented by the above formula (y-al-1), formula (y-al-3), or formula (y-al-6) is even more preferred.

In the formula (a0-1), V ⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group in V ⁰¹ preferably have 1 to 4 carbon atoms. Examples of the fluorinated alkylene group in V ⁰¹ include groups in which some or all of the hydrogen atoms of the alkylene group in V ⁰¹ are substituted with fluorine atoms.
Among these, V ⁰¹ is preferably a linear alkylene group having 1 to 4 carbon atoms, a linear fluorinated alkylene group having 1 to 4 carbon atoms, or a single bond, and is preferably a methylene group (-CH ₂ - ), an ethylene group (-CH ₂ CH ₂ -), and a linear fluorinated alkylene group having 1 to 3 carbon atoms are more preferable.
However, in the formula (a0-1), Y ⁰¹ and V ⁰¹ do not form a single bond at the same time.

In the formula (a0-1), R ⁰³ is preferably a fluorine atom or a fluorinated alkyl group, more preferably a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms, and R 03 is a fluorine atom or a fluorinated alkyl group. It is even more preferable that there be.

Preferred specific examples of the anion moiety of the structural unit (a0) are shown below.

The anion moiety of the structural unit (a0) is preferably an anion represented by any of the formulas (a0-an-1) to (a0-an-12), and is preferably an anion represented by any of the formulas (a0-an-1) to (a0-an-1) to (a0-an-1) to (a0-an-1). a0-an-5) and an anion represented by any one of formulas (a0-an-9) to (a0-an-11) are more preferred.

In the formula (a0-1), M ^m+ is an m-valent onium cation, and m is an integer of 1 or more. The onium cation in M ^m+ is preferably a sulfonium cation or an iodonium cation.
Preferred cation moieties ((M ^m+ ) _1/m ) include onium cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[In the formula, R ²⁰¹ to R ²⁰⁷ each independently represent an aryl group, an alkyl group, or an alkenyl group that may have a substituent. R ²⁰¹ to R ²⁰³ and R ²⁰⁶ to R ²⁰⁷ may be bonded to each other to form a ring together with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R ²¹⁰ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or -SO ₂ - which may have a substituent. It is a containing cyclic group. L ²⁰¹ represents -C(=O)- or -C(=O)-O-. ]

In the above general formulas (ca-1) to (ca-3), examples of the aryl group in R ²⁰¹ to R ²⁰⁷ include unsubstituted aryl groups having 6 to 20 carbon atoms, such as phenyl group and naphthyl group. preferable.
The alkyl group in R ²⁰¹ to R ²⁰⁷ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group in R ²⁰¹ to R ²⁰⁷ preferably has 2 to 10 carbon atoms.
Examples of the substituent that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and the following general formula: Examples include groups represented by (car-r-1) to (car-r-7), respectively.

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

Cyclic group that may have a substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Aliphatic hydrocarbon group means a hydrocarbon group without aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

The aromatic hydrocarbon group in R' ²⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, Most preferably 6 to 10 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in substituents.
Specifically, the aromatic ring possessed by the aromatic hydrocarbon group in R' ²⁰¹ is benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a ring in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. and aromatic heterocycles. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group in R' ²⁰¹ is a group in which one hydrogen atom is removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one of the hydrogen atoms in the aromatic ring is alkylene Examples include groups substituted with groups (eg, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The 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.

Examples of the cyclic aliphatic hydrocarbon group for R' ²⁰¹ include aliphatic hydrocarbon groups containing a ring in the structure.
The aliphatic hydrocarbon group containing a ring in its structure includes an alicyclic hydrocarbon group (a group in which one hydrogen atom is removed from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkanes include polycycloalkanes having polycyclic skeletons such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; condensed ring systems such as cyclic groups having steroid skeletons; More preferred are polycycloalkanes having a polycyclic skeleton.

Among these, as the cyclic aliphatic hydrocarbon group for R' ²⁰¹ , a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane is preferable, and a group obtained by removing one hydrogen atom from a polycycloalkane is preferable. More preferred are adamantyl groups and norbornyl groups, and most preferred are adamantyl groups.

The linear or branched aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. , more preferably 1 to 4 carbon atoms, particularly preferably 1 to 3 carbon atoms.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other 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 Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; -CH(CH ₃ )CH ₂ CH ₂ -, alkyltrimethylene groups such as -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ )CH ₂ CH ₂ -, and the like. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

Further, the cyclic hydrocarbon group in R' ²⁰¹ may contain a heteroatom such as a heterocycle. Examples include lactone-containing cyclic groups, -SO ₂ --containing cyclic groups, and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16), respectively.

Examples of the substituent in the cyclic group of R' ²⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, and the like.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group. Most preferred are methoxy and ethoxy groups.
As the halogen atom as a substituent, a fluorine atom is preferable.
Examples of the halogenated alkyl group as a substituent include an alkyl group having 1 to 5 carbon atoms, such as a methyl group, ethyl group, propyl group, n-butyl group, and tert-butyl group, in which some or all of the hydrogen atoms are Examples include groups substituted with the aforementioned halogen atoms.
The carbonyl group as a substituent is a group that substitutes a methylene group (-CH ₂ -) constituting a cyclic hydrocarbon group.

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

Chain-like alkenyl group which may have a substituent:
The chain alkenyl group for R' ²⁰¹ may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and The number of carbon atoms is more preferably 2 to 4, and the number of carbon atoms is particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, and 2-methylpropenyl group.
As the chain alkenyl group, among the above, a straight chain alkenyl group is preferable, a vinyl group and a propenyl group are more preferable, and a vinyl group is particularly preferable.

Examples of substituents on the chain alkyl group 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 a cyclic group in the above R' ²⁰¹ . etc.

The cyclic group that may have a substituent, the chain alkyl group that may have a substituent, or the chain alkenyl group that may have a substituent for ^R'201 is other than those mentioned above. , as a cyclic group that may have a substituent or a chain alkyl group that may have a substituent, those similar to the acid-dissociable group represented by the above formula (a1-r-2) can also be mentioned.

Among these, R' ²⁰¹ is preferably a cyclic group that may have a substituent, and more preferably a cyclic hydrocarbon group that may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group; a -SO ₂ --containing cyclic group, and the like are preferable.

In the above general formulas (ca-1) to (ca-3), R ²⁰¹ to R ²⁰³ and R ²⁰⁶ to R ²⁰⁷ are sulfur atoms, when bonding with each other to form a ring with the sulfur atom in the formula; Heteroatoms such as oxygen atoms and nitrogen atoms, carbonyl groups, -SO-, -SO ₂ -, -SO ₃ -, -COO-, -CONH- or -N(R _N )- (where R _N is a carbon atom They may be bonded via a functional group such as an alkyl group of numbers 1 to 5.). As for the ring to be formed, one ring in the formula containing a sulfur atom in its ring skeleton is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring. preferable. Specific examples of the ring formed include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiine ring, a tetrahydrothiophenium ring, a tetrahydrothio Examples include a pyranium 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, and when they are an alkyl group, they are bonded to each other. may be used 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 -SO ₂ - which may have a substituent. It is a containing cyclic group.
Examples of the aryl group for R ²¹⁰ include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred.
The alkyl group for R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms.
The —SO ₂ —-containing cyclic group which may have a substituent in R ²¹⁰ is preferably a “—SO ₂ —containing polycyclic group.”

Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-75).

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

[In the formula, R'' ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as the substituent that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have. ]

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

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

Among the above, as M ^m+ , a cation represented by the above formula (ca-1) is preferable.
Further, as M ^m+ , an m-valent onium cation having a fluorine atom is preferable from the viewpoint of increasing sensitivity. This M ^m+ is preferably a cation represented by the following formula (ca-1-1).

[In the formula, Rf ²⁰¹ to Rf ²⁰³ each independently represent an aryl group that may have a substituent, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent] . Rf ²⁰¹ to Rf ²⁰³ may be bonded to each other to form a ring together with the sulfur atom in the formula. However, at least one of Rf ²⁰¹ to Rf ²⁰³ contains at least one fluorine atom. ]

Rf ²⁰¹ to Rf ²⁰³ in the formula (ca-1-1) are the same as R ²⁰¹ to R ²⁰³ in the formula (ca-1), respectively. However, at least one of Rf ²⁰¹ to Rf ²⁰³ contains at least one fluorine atom. The cation represented by formula (ca-1-1) preferably contains three or more fluorine atoms. Any one of Rf ²⁰¹ to Rf ²⁰³ may have three or more fluorine atoms, and the total number of fluorine atoms contained in Rf ²⁰¹ to Rf ²⁰³ may be three or more.

Specific examples of the structural unit (a0) are listed below, but the invention is not limited thereto.

The structural unit (a0) is preferably a structural unit represented by any of the formulas (a0-1) to (a0-13), and is preferably a structural unit represented by any of the formulas (a0-1) to (a0-6), the formula (a0-1) to -10) to (a0-12) are more preferred.

The number of structural units (a0) contained in the component (A1) may be one or more.
The proportion of the structural unit (a0) in the component (A1) is preferably 5 to 50 mol%, and 10 to 45 mol%, based on the total (100 mol%) of all the structural units constituting the component (A1). It is more preferably 20 to 40 mol%, even more preferably 25 to 35 mol%.
When the proportion of the structural unit (a0) is at least the lower limit of the above-mentioned preferable range, sensitivity is further improved. When the proportion of the structural unit (a0) is below the upper limit of the preferable range, lithography properties such as pattern size uniformity are further improved.

≪Other constituent units≫
In addition to the above-mentioned structural unit (a0), the component (A1) may have other structural units as necessary.
Other structural units include, for example, the structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid (excluding those corresponding to the structural unit (a0)); the general formula (a10- Structural unit (a10) represented by 1); Structural unit (a2) containing a lactone-containing cyclic group; Structural unit (a8) derived from a compound represented by general formula (a8-1) described below, etc. Can be mentioned.

Constituent unit (a1):
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases under the action of an acid.
Examples of the acid-dissociable group constituting the acid-decomposable group include those that have been proposed as acid-dissociable groups for base resins for chemically amplified resist compositions.
Examples of acid-dissociable groups proposed as acid-dissociable groups for base resins for chemically amplified resist compositions include "acetal-type acid-dissociable groups,""tertiary alkyl ester-type acid-dissociable groups," and "tertiary acid-dissociable groups." Examples include "class alkyloxycarbonyl acid dissociable group" and "secondary alkyl ester type acid dissociable group."
Regarding the "acetal type acid dissociable group", "tertiary alkyl ester type acid dissociable group", and "secondary alkyl ester type acid dissociable group" in the structural unit (a1), the above-mentioned structural unit (a0) These are the same as the "acetal type acid dissociable group", "tertiary alkyl ester type acid dissociable group", and "secondary alkyl ester type acid dissociable group" explained in .

Tertiary alkyloxycarbonylic acid dissociable group:
Examples of the tertiary alkyloxycarbonyl acid dissociable group include acid dissociable groups represented by the following general formula (a1-r-3).

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

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

The structural unit (a1) is a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, a structural unit derived from acrylamide, hydroxystyrene or hydroxyl. A structural unit in which at least a portion of the hydrogen atoms in the hydroxyl group of a structural unit derived from a styrene derivative is protected by a substituent containing the acid-decomposable group, a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative, - Examples include structural units in which at least a portion of the hydrogen atoms in C(=O)-OH are protected by a substituent containing the acid-decomposable group.

Among the above-mentioned structural units, structural units (a1) are preferably structural units derived from acrylic esters in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent.
Preferred specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2).

[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 general formula (a1-r-1), (a1-r-2) or (a1-r-4). Wa ¹ is n _a2 + monovalent hydrocarbon group, n _a2 is an integer of 1 to 3, and Ra ² is represented by the above general formula (a1-r-1) or (a1-r-3). It is an acid dissociable group. ]

In the formula (a1-1), 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 from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferred.

In the formula (a1-1), the divalent hydrocarbon group in Va ¹ 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, and is usually preferably saturated.
More specifically, the aliphatic hydrocarbon group includes a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, and the like.

The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and has 1 to 4 carbon atoms. 3 is most preferred.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.
The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and has 3 carbon atoms. Most preferred.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other 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 Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; -CH(CH ₃ )CH ₂ CH ₂ -, alkyltrimethylene groups such as -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ )CH ₂ CH ₂ -, and the like. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group in which the alicyclic hydrocarbon group is linear or branched. Examples include a group bonded to the end of a chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms. Specifically, Examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. preferable. However, the number of carbon atoms does not include the number of carbon atoms in the substituents.
Specifically, examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; Examples include aromatic heterocycles substituted with atoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group includes a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group); ) in which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group) (a group obtained by removing one hydrogen atom from an aryl group in the group), and the like. The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In the formula (a1-1), Ra ¹ is an acid-dissociable group represented by the general formula (a1-r-1), (a1-r-2) or (a1-r-4), An acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4) is preferable.

In the formula (a1-2), the n _a2 +1-valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group without aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. The aliphatic hydrocarbon group is a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a linear or branched aliphatic hydrocarbon group. Examples include groups in which a ring-containing aliphatic hydrocarbon group is combined in the structure.
The n _a2 +1 valence is preferably 2 to 4, more preferably 2 or 3.

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

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

The number of structural units (a1) contained in the component (A1) may be one or more.
As the structural unit (a1), the structural unit represented by the above formula (a1-1) is more preferable because the characteristics (sensitivity, shape, etc.) in lithography using electron beam or EUV can be more easily improved; for EB Alternatively, it is preferable to select one in which the acid-dissociable group is a cyclic group because it is suitable for EUV use because of enhanced reactivity.
The structural unit (a1) is a structural unit represented by the above formula (a1-1), in which Ra ¹ is represented by the above general formula (a1-r-2) or (a1-r-4). More preferably, it is an acid-dissociable group; a structural unit represented by the above formula (a1-1), in which Ra ¹ is an acid-dissociable group represented by the above general formula (a1-r-2); Particularly preferred is a structural unit represented by the above formula (a1-1), in which Ra ¹ is an acid-dissociable group represented by the above general formula (a1-r2-1). is most preferable.

The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 40 mol%, and 10 to 30 mol%, based on the total (100 mol%) of all structural units constituting the component (A1). is more preferable, and even more preferably 15 to 25 mol%.
By setting the proportion of the structural unit (a1) to the lower limit of the above-mentioned preferred range or more, lithography properties such as sensitivity, resolution, and uniformity of pattern dimensions are improved. On the other hand, if it is below the upper limit of the above-mentioned preferable range, a balance with other structural units can be maintained, and various lithography properties will be improved.

Constituent unit (a10):
The structural unit (a10) is a structural 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. Ya ^x1 is a single bond or a divalent linking group. Wa ^x1 is an aromatic hydrocarbon group which may have a substituent. n _ax1 is an integer of 1 or more. ]

In the formula (a10-1), 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. Particularly preferred are atoms or methyl groups.

In the formula (a10-1), Ya ^x1 is a single bond or a divalent linking group.
The divalent linking group in Ya ^x1 is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.
Ya ^x1 is a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), or a linear or branched alkylene group. , or a combination thereof is preferable, and a single bond or an ester bond [-C(=O)-O-, -OC(=O)-] is more preferable.

In the formula (a10-1), Wa ^x1 is an aromatic hydrocarbon group which may have a substituent.
Examples of the aromatic hydrocarbon group in Wa ^x1 include a group obtained by removing (na _x1 +1) hydrogen atoms from an aromatic ring that may have a substituent. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; can be mentioned. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
In addition, the aromatic hydrocarbon group in Wa ^x1 is an aromatic compound containing an aromatic ring that may have two or more substituents (e.g. biphenyl, fluorene, etc.) by removing (n _ax1 +1) hydrogen atoms. Other groups may also be mentioned.
Among the above, Wa ^x1 is preferably a group obtained by removing ( _nax1 +1) hydrogen atoms from benzene, naphthalene, anthracene, or biphenyl, and a group obtained by removing ( _nax1 +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 substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those listed as the substituent for the cyclic group of ^R'201 . The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, and is preferably an ethyl group or a methyl group. A group is more preferred, and a methyl group is particularly preferred. The aromatic hydrocarbon group in Wa ^x1 preferably has no substituent.

In the formula (a10-1), n _ax1 is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, even more preferably 1, 2 or 3, and 1 or 2 is Particularly preferred.

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

The number of structural units (a10) contained in the component (A1) may be one or more.
When the component (A1) has a structural unit (a10), the proportion of the structural unit (a10) in the component (A1) is as follows: It is preferably 40 to 95 mol%, more preferably 45 to 90 mol%, even more preferably 50 to 80 mol%, and particularly preferably 60 to 75 mol%.
By setting the proportion of the structural unit (a10) to the lower limit of the above-mentioned preferred range or more, the sensitivity can be more easily increased. On the other hand, by setting it below the upper limit, it becomes easier to maintain a balance with other structural units.

Constituent unit (a2):
Component (A1) may have a structural unit (a2) containing a lactone-containing cyclic group (excluding the structural unit (a1)).
The lactone-containing cyclic group of the structural unit (a2) is effective in increasing the adhesion of the resist film to the substrate when the component (A1) is used to form the resist film. In addition, by having the structural unit (a2), for example, the acid diffusion length can be appropriately adjusted, the adhesion of the resist film to the substrate can be increased, and the solubility during development can be appropriately adjusted, so that the lithography properties can be improved. etc. will be good.

The term "lactone-containing cyclic group" refers to a cyclic group containing a ring containing -OC(=O)- (lactone ring) in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, 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.
The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any arbitrary group can be used. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be mentioned.

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

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

In -COOR" and -OC(=O)R" in Ra' ²¹ , R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group.
The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms.
When R'' is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is a methyl or ethyl group. is particularly preferred.
When R'' is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms.Specifically, , a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; bicycloalkane, tricycloalkane, tetracycloalkane, etc. Examples include groups obtained by removing one or more hydrogen atoms from a polycycloalkane. More specifically, groups obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane and cyclohexane; adamantane, norbornane, Examples include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as isobornane, tricyclodecane, and tetracyclododecane.
Examples of the lactone-containing cyclic group in R'' include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7).
The hydroxyalkyl group in Ra' ²¹ preferably has 1 to 6 carbon atoms, and specifically includes a group in which at least one hydrogen atom of the alkyl group in Ra' ²¹ is substituted with a hydroxyl group. It will be done.

Among the above, Ra' ²¹ is preferably each independently a hydrogen atom or a cyano group.

In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A'' is linear or branched. Preferred are alkylene groups such as methylene group, ethylene group, n-propylene group, isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples include the terminal or sulfur atom of the alkylene group. Examples include groups in which -O- or -S- is present between carbon atoms, such as -O-CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S -CH ₂ -, etc. A'' is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

Specific examples of groups represented by general formulas (a2-r-1) to (a2-r-7) are listed below.

Among these, the structural unit (a2) is preferably a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent.
The structural unit (a2) is preferably a structural 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 is -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 does not become -CO-. Ra ²¹ is a lactone-containing cyclic group. ]

In the formula (a2-1), 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. Particularly preferred are atoms or methyl groups.

In the formula (a2-1), the divalent linking group for Ya ²¹ is not particularly limited, but includes a divalent hydrocarbon group that may have a substituent, a divalent linking group containing a hetero atom, etc. are preferably 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 formula (a2-1), Ya ²¹ is preferably a single bond, and La ²¹ is preferably -COO- or -OCO-.

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group.
Preferable examples of the lactone-containing cyclic group in Ra ²¹ include groups represented by the aforementioned general formulas (a2-r-1) to (a2-r-7).

The number of structural units (a2) contained in the component (A1) may be one or more.
When the component (A1) has a structural unit (a2), the proportion of the structural unit (a2) is 1 to 20 mol% with respect to the total (100 mol%) of all structural units constituting the component (A1). It is preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%.
When the proportion of the structural unit (a2) is at least the lower limit of the above-mentioned preferable range, the effect of containing the structural unit (a2) can be sufficiently obtained, and when it is below the upper limit, other effects can be obtained. It is possible to maintain a balance with the structural units of , and various lithography properties can be improved.

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

[In the formula, W ² is a polymerizable group-containing group. Ya ^x2 is a single bond or a (na _x2 +1)-valent linking group. Ya ^x2 and W ² may form a condensed ring. R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms. R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom, or a hydrogen atom. R ² and Ya ^x2 may be bonded to each other to form a ring structure. n _ax2 is an integer from 1 to 3. ]

The "polymerizable group" in the polymerizable group-containing group of ^W2 is a group that enables a compound having a polymerizable group to be polymerized by radical polymerization, etc. A group containing multiple bonds.

The polymerizable group-containing group may be a group consisting only of a polymerizable group, or a group consisting of a polymerizable group and another group other than the polymerizable group. Examples of groups other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.
Preferred examples of the polymerizable group-containing group include a group represented by the chemical formula: C(R ^X11 )(R ^X12 )=C(R ^X13 )-Ya ^x0 -.
In ^this chemical formula, R ^X11 , R ^X12 , and ^R It is a divalent linking group.

The fused ring formed by Ya ^x2 and W ² includes a fused ring formed by the polymerizable group at the W ² site and Ya ^x2 , and a fused ring formed by Ya ^x2 and a group other than the polymerizable group at the W ² site. Examples include fused rings.
The condensed ring formed by Ya ^x2 and W ² may have a substituent.

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

The number of structural units (a8) contained in the component (A1) may be one or more.
When the component (A1) has a structural unit (a8), the proportion of the structural unit (a8) is 1 to 20 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). It is preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%.

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

The component (A1) used in this embodiment is a polymer compound having a structural unit (a0), preferably a polymer compound having a repeating structure of a structural unit (a0) and a structural unit (a10); a structural unit Examples include polymer compounds having a repeating structure of (a0), a structural unit (a1), and a structural unit (a10).

The component (A1) is prepared by dissolving monomers for inducing each structural unit in a polymerization solvent, and then initiating radical polymerization of, for example, azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (for example, V-601, etc.). It can be manufactured by adding an agent and polymerizing it.
For example, the component (A1) can be prepared by dissolving a monomer inducing the structural unit (a0) and a monomer inducing the structural unit (a10) in a polymerization solvent, and then adding the above-mentioned radical polymerization initiator thereto. It can be produced by additionally polymerizing and then performing a deprotection reaction.
In addition, during polymerization, for example, by using a chain transfer agent such as HS-CH ₂ -CH ₂ -CH ₂ -C(CF ₃ ) ₂ -OH in combination, -C(CF ₃ ) is added to the terminal. ₂ -OH group may be introduced. In this way, a copolymer into which a hydroxyalkyl group is introduced in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms can reduce development defects and reduce LER (line edge roughness: unevenness of line sidewalls). It is effective in reducing

The weight average molecular weight (Mw) of the component (A1) (polystyrene conversion standard determined by gel permeation chromatography (GPC)) is not particularly limited, and is preferably from 1,000 to 40,000, more preferably from 2,000 to 20,000, and from 5,000 to 10,000 is more preferable.
When the Mw of component (A1) is below the preferable upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is above the preferable lower limit of this range, it has good dry etching resistance. The cross-sectional shape of the resist pattern is good.
The molecular weight dispersity (Mw/Mn) of component (A1) is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, particularly 1.0 to 2.0. preferable. In addition, Mn indicates a number average molecular weight.

・About the (A2) component The resist composition of the present embodiment contains, as the (A) component, a base material component (hereinafter referred to as "(A2) ) may be used in combination.
The component (A2) is not particularly limited, and may be arbitrarily selected from a large number of components conventionally known as base components for chemically amplified resist compositions.
As component (A2), one type of high molecular compound or low molecular compound may be used alone, or two or more types may be used in combination.

The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and 100% by mass, based on the total mass of component (A). It may be. When the proportion is 25% by mass or more, a resist pattern that is excellent in various lithography properties such as high sensitivity, resolution, and uniformity of pattern dimensions is easily formed.

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

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

≪Acid generator component (B)≫
The resist composition of this embodiment may further contain an acid generator component (B) that generates acid upon exposure.
Component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resist compositions can be used.
Such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts; oxime sulfonate acid generators; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl)diazomethanes; Acid generators include a wide variety of acid generators such as nitrobenzylsulfonate acid generators, iminosulfonate acid generators, and disulfone acid generators.

Examples of onium salt-based acid generators include compounds represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), and compounds represented by the general formula (b-2). Examples include a compound (hereinafter also referred to as "component (b-2)") or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[In the formula, R ¹⁰¹ and R ¹⁰⁴ to R ¹⁰⁸ each independently represent a cyclic group that may have a substituent, a chain alkyl group that may have a substituent, or a substituent. It is a chain alkenyl group that may have. R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring structure. R ¹⁰² is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y ¹⁰¹ is a divalent linking group or a single bond containing an oxygen atom. V ¹⁰¹ to V ¹⁰³ each independently represent a single bond, an alkylene group, or a fluorinated alkylene group. L ¹⁰¹ to L ¹⁰² are each independently a single bond or an oxygen atom. L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -. m is an integer of 1 or more, and M' ^m+ is an m-valent onium cation. ]

{Anion part}
- Anion in component (b-1) In formula (b-1), R ¹⁰¹ is a cyclic group that may have a substituent, a chain alkyl group that may have a substituent, or a substituent It is a chain alkenyl group which may have.

Cyclic group that may have a substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Aliphatic hydrocarbon group means a hydrocarbon group without aromaticity. Moreover, it is preferable that the aliphatic hydrocarbon group is saturated.

The aromatic hydrocarbon group in R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. . However, the number of carbon atoms does not include the number of carbon atoms in substituents.
Specifically, the aromatic ring possessed by the aromatic hydrocarbon group in R ¹⁰¹ is benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples include aromatic heterocycles. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group in R ¹⁰¹ includes a group in which one hydrogen atom is removed from the aromatic ring (aryl group: e.g., phenyl group, naphthyl group, etc.), a group in which one hydrogen atom in the aromatic ring is alkylene Examples include groups substituted with groups (eg, benzyl group, phenethyl group, 1-naphthylmethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

Examples of the cyclic aliphatic hydrocarbon group in R ¹⁰¹ include aliphatic hydrocarbon groups containing a ring in the structure.
The aliphatic hydrocarbon group containing a ring in its structure includes an alicyclic hydrocarbon group (a group in which one hydrogen atom is removed from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkanes include polycycloalkanes having polycyclic skeletons such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; condensed ring systems such as cyclic groups having steroid skeletons; More preferred are polycycloalkanes having a polycyclic skeleton.

Among these, as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ , a group obtained by removing one or more hydrogen atoms from a monocycloalkane or polycycloalkane is preferable, and a group obtained by removing one hydrogen atom from a polycycloalkane is more preferable. Preferably, an adamantyl group and a norbornyl group are more preferable, and an adamantyl group is particularly preferable.

The linear aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. , 1 to 3 are most preferred. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.
The branched aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, and even more preferably 3 or 4 carbon atoms. , 3 are most preferred. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other 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 Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; -CH(CH ₃ )CH ₂ CH ₂ -, alkyltrimethylene groups such as -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ )CH ₂ CH ₂ -, and the like. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

Furthermore, the cyclic hydrocarbon group in R ¹⁰¹ may contain a heteroatom such as a heterocycle. Specifically, lactone-containing cyclic groups represented by the above general formulas (a2-r-1) to (a2-r-7), respectively, and the following general formulas (b5-r-1) to (b5-r- -SO ₂ --containing cyclic groups represented by 4), and heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16), respectively.
In the formula, * represents a bond bonded to Y ¹⁰¹ in formula (b-1).

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

Rb' ⁵¹ , B", and n' in the general formulas (b5-r-1) to (b5-r-4) are represented by the general formulas (a0-s-1) to (a0-s-4) ), respectively, are the same as Rb' ⁵¹ , B'', and n'.

Specific examples of groups represented by general formulas (b5-r-1) to (b5-r-4) are listed below. "Ac" in the formula represents an acetyl group.

Examples of the substituent in the cyclic group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, and the like.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group. Most preferred are methoxy and ethoxy groups.
The halogen atom used as a substituent is preferably a fluorine atom, a bromine atom, or an iodine atom.
Examples of the halogenated alkyl group as a substituent include an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc., in which some or all of the hydrogen atoms are Examples include groups substituted with the aforementioned halogen atoms.
The carbonyl group as a substituent is a group that substitutes a methylene group (-CH ₂ -) constituting a cyclic hydrocarbon group.

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

Examples of substituents that the fused cyclic group in R ¹⁰¹ may have include alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxyl groups, carbonyl groups, nitro groups, aromatic hydrocarbon groups, and aliphatic groups. Examples include cyclic hydrocarbon groups.
Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as a substituent for the fused cyclic group include those listed as the substituent for the cyclic group in R ¹⁰¹ above.
Examples of the aromatic hydrocarbon group as a substituent for the fused cyclic group include a group in which one hydrogen atom is removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom is removed from the aromatic ring, A group in which one of the groups is substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), the above Examples include heterocyclic groups represented by the chemical formulas (r-hr-1) to (r-hr-6), respectively.
Examples of the alicyclic hydrocarbon group as a substituent for the fused cyclic group include groups obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane and cyclohexane; adamantane, norbornane, isobornane, tricyclodecane, and tetracycloalkane; A group obtained by removing one hydrogen atom from a polycycloalkane such as cyclododecane; a lactone-containing cyclic group represented by the above general formulas (a2-r-1) to (a2-r-7); a lactone-containing cyclic group represented by the above general formula -SO ₂ --containing cyclic groups represented by (b5-r-1) to (b5-r-4), respectively; represented by the formulas (r-hr-7) to (r-hr-16), respectively; Examples include heterocyclic groups such as

Chain-like alkyl group which may have a substituent:
The chain alkyl group for R ¹⁰¹ may be either linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

Chain-like alkenyl group which may have a substituent:
The chain alkenyl group for R ¹⁰¹ may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, and even more preferably 2 to 4 carbon atoms. 3 is particularly preferred. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, and 2-methylpropenyl group.
As the chain alkenyl group, among the above, a straight chain alkenyl group is preferable, a vinyl group and a propenyl group are more preferable, and a vinyl group is particularly preferable.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ 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 R ¹⁰¹ above. Can be mentioned.

Among the above, R ¹⁰¹ is preferably a cyclic group that may have a substituent, and more preferably a cyclic hydrocarbon group that may have a substituent.
More specifically, the cyclic hydrocarbon group includes a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; the general formulas (a2-r-1) to (a2-r- 7) Lactone-containing cyclic groups represented by formulas (b5-r-1) to (b5-r- ₄ ) are preferred, and polycycloalkane-containing cyclic groups are preferred. A group obtained by removing one or more hydrogen atoms from is more preferable, and an adamantyl group is even more preferable.

In formula (b-1), Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain atoms other than the oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include linking groups represented by the above general formulas (y-al-1) to (y-al-8), respectively. In addition, in the general formulas (y-al-1) to (y-al-8), the bond to R ¹⁰¹ in the above formula (b-1) is the general formula (y-al-1) to (y-al-1) to (y-al-8). -al-8) is V' ¹⁰¹ .

Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, each represented by the above formulas (y-al-1) to (y-al-6). A linking group is more preferred.

In formula (b-1), V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group in V ¹⁰¹ preferably have 1 to 4 carbon atoms. Among these, V ¹⁰¹ is preferably a single bond or a linear alkylene group having 1 to 4 carbon atoms.
However, Y ¹⁰¹ and V ¹⁰¹ in formula (b-1) do not simultaneously become a single bond.

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

Specific examples of the anion moiety represented by the formula (b-1) include, for example, when Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anions and perfluorobutanesulfonate anions. ; When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, examples thereof include anions represented by any of the following formulas (an-1) to (an-3).

[In the formula, ^R''101 is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), respectively. A cyclic group, a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a chain alkyl group that may have a substituent, or a chain alkyl group that has a substituent. ^R''102 is an aliphatic cyclic group which may have a substituent, and is represented by the above formula (r-br-1) or (r-br-2). a fused cyclic group represented by the general formula (a2-r-1), (a2-r-3) to (a2-r-7), or a lactone-containing cyclic group represented by the general formula (b5- -SO ₂ --containing cyclic groups represented by r-1) to (b5-r-4), respectively. ^R''103 is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. V" ¹⁰¹ is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. v'' are each independently an integer from 0 to 3, q'' are each independently an integer from 0 to 20, and n'' is 0 or 1.]

The aliphatic cyclic group which may have a substituent for R'' ¹⁰¹ , R'' ¹⁰² and R'' ¹⁰³ is the group exemplified as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ in formula (b-1) above. It is preferable that the substituent is the same as the substituent that may substitute the cyclic aliphatic hydrocarbon group in R ¹⁰¹ in the formula (b-1).

The aromatic cyclic group which may have a substituent in R" ¹⁰¹ and R" ¹⁰³ is the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R ¹⁰¹ in formula (b-1) above. It is preferable that Examples of the substituent include the same substituents that may substitute the aromatic hydrocarbon group in R ¹⁰¹ in formula (b-1).

The chain alkyl group which may have a substituent in R'' ¹⁰¹ is preferably the group exemplified as the chain alkyl group in R ¹⁰¹ in formula (b-1) above.
The chain alkenyl group which may have a substituent in R'' ¹⁰³ is preferably the group exemplified as the chain alkenyl group in R ¹⁰¹ in formula (b-1) above.

The alkylene group and fluorinated alkylene group in V" ¹⁰¹ preferably have 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms. Specific examples of V" ¹⁰¹ include -CH ₂ -, -( Examples include CH ₂ ) ₂ -, -CFH-, -CH ₂ CFH-, -CH(CF ₃ )-, and the like.

The anion moiety represented by the formula (b-1) is preferably an anion moiety represented by the formula (an-1). Among these, those in which ^R''101 in (an-1) is an aromatic cyclic group which may have a substituent are preferable, and those which are a phenyl group which may have a substituent are more preferable. Examples of the substituent include a hydroxy group, an alkyl group, or a halogen atom.The halogen atom is preferably a bromine atom or an iodine atom, and more preferably an iodine atom.

・Anion in component (b-2) In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ each independently represent a cyclic group that may have a substituent, or a chain group that may have a substituent. is an alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include those similar to R ¹⁰¹ in formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably a chain alkyl group that may have a substituent, and are a linear or branched alkyl group or a linear or branched fluorinated alkyl group. is more preferable.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. The number of carbon atoms in the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible within the range of the number of carbon atoms mentioned above, for reasons such as good solubility in a resist solvent. In addition, in the chain alkyl groups of R ¹⁰⁴ and R ¹⁰⁵ , the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and the higher the resistance to high energy light and electron beams of 250 nm or less. This is preferable because it improves transparency. The proportion of fluorine atoms in the chain alkyl group, that is, the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. It is a perfluoroalkyl group.
In formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each of them is the same as V ¹⁰¹ in formula (b-1). Can be mentioned.
In formula (b-2), L ¹⁰¹ and L ¹⁰² are each independently a single bond or an oxygen atom.

・Anion in component (b-3) In formula (b-3), R ¹⁰⁶ to R ¹⁰⁸ each independently represent a cyclic group that may have a substituent, or a chain that may have a substituent. is an alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include those similar to R ¹⁰¹ in formula (b-1).
In formula (b-3), L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -.

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

Preferred cation moieties ((M' ^m+ ) _1/m ) include onium cations represented by the above general formulas (ca-1) to (ca-3), respectively. As the cation moiety, cations represented by the general formula (ca-1) are more preferred, and cations represented by the formulas (ca-1-1) to (ca-1-75) are even more preferred.

In the resist composition of the present embodiment, the component (B) may be used alone or in combination of two or more. In the resist composition of this embodiment, since the component (A1) has the structural unit (a0), it is not necessary to contain the component (B).
Among the above, component (b-1) is preferred as component (B).

The content of component (B) in the resist composition is preferably 0 to 30 parts by weight, more preferably 0 to 20 parts by weight, and even more preferably 0 to 10 parts by weight, based on 100 parts by weight of component (A1).
By setting the content of component (B) within the above-mentioned preferred range, a uniform solution is easily obtained when each component of the resist composition is dissolved in an organic solvent, and the resist composition has good storage stability. This is preferable.

<<Base component (D)>>
In addition to component (A), the resist composition of this embodiment further contains a base component (hereinafter also referred to as "component (D)") that traps the acid generated by exposure (that is, controls the diffusion of acid). It is preferable to contain. Component (D) acts as a quencher (acid diffusion control agent) that traps acid generated by exposure in the resist composition.
Component (D) includes, for example, a photodegradable base (D1) that decomposes upon exposure and loses acid diffusion controllability (hereinafter referred to as "component (D1)"), and a nitrogen-containing organic compound that does not fall under the component (D1). Compound (D2) (hereinafter referred to as "component (D2)") and the like can be mentioned. Among these, a photodegradable base (component (D1)) is preferred because it can easily improve the uniformity of pattern dimensions and the ability to reduce roughness. Furthermore, by containing the component (D1), it becomes easier to improve both the characteristics of increasing sensitivity and suppressing the occurrence of coating defects. The compound exemplified as component (D1) described below may be used as the above-mentioned acid generator component (component (B)) depending on the combination with other compounds.

- Regarding component (D1) By using a resist composition containing component (D1), when forming a resist pattern, the contrast between exposed areas and unexposed areas of the resist film can be further improved.
Component (D1) is not particularly limited as long as it decomposes upon exposure and loses acid diffusion control properties, and may be a compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)"). ), a compound represented by the following general formula (d1-2) (hereinafter referred to as "(d1-2) component"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "(d1-2) component"). 3) One or more compounds selected from the group consisting of "components" are preferred.
Components (d1-1) to (d1-3) do not act as quenchers because they decompose in the exposed areas of the resist film and lose their acid diffusion control properties (basicity), but they do not act as quenchers in the unexposed areas of the resist film. Acts as a char.

[In the formula, Rd ¹ to Rd ⁴ are 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. It is. However, it is assumed that no fluorine atom is bonded to the carbon atom adjacent to the S atom in Rd ² in formula (d1-2). Yd ¹ is a single bond or a divalent linking group. m is an integer of 1 or more, and M ^m+ are each independently an m-valent onium cation. ]

{(d1-1) component}
...Anion moiety In formula (d1-1), Rd ¹ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkyl group which may have a substituent. It is a good chain alkenyl group, and the same groups as R' ²⁰¹ above can be mentioned.
Among these, Rd ¹ is an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain type which may have a substituent. Alkyl groups are preferred. Examples of substituents that these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, and the above general formulas (a2-r-1) to (a2-r- Examples include a lactone-containing cyclic group represented by 7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is included as a substituent, it may be via an alkylene group, and in this case, the substituent is represented by the above formulas (y-al-1) to (y-al-6), respectively. A linking group is preferred. In addition, an aromatic hydrocarbon group, an aliphatic cyclic group, or a chain alkyl group in Rd ¹ is represented by the above general formulas (y-al-1) to (y-al-8), respectively, as a substituent. In the above general formulas (y-al-1) to (y-al-8), an aromatic hydrocarbon group or an aliphatic cyclic group in Rd ¹ in formula (d3-1) V′ ¹⁰¹ in the above general formulas (y-al-1) to (y-al-8) is bonded to the carbon atom constituting the , or chain alkyl group.
Preferred examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and other ring structures).
The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically includes a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, and octyl group. , nonyl group, decyl group, etc.; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1- Examples include branched alkyl groups such as ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8. 1 to 4 are more preferred. 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 anion moiety of component (d1-1) are shown below.

...Cation part In formula (d1-1), M ^m+ is an m-valent onium cation.
As the onium cation of M ^m+ , the same cations as the cations represented by the above general formulas (ca-1) to (ca-3) are preferably mentioned, and the onium cations represented by the above general formula (ca-1) are preferably mentioned. Cations are more preferred, and cations represented by the formulas (ca-1-1) to (ca-1-75) are even more preferred.
Component (d1-1) may be used alone or in combination of two or more.

{(d1-2) component}
...Anion moiety In formula (d1-2), Rd ² is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkyl group which may have a substituent. It is a good chain alkenyl group, and examples include those similar to R' ²⁰¹ above.
However, it is assumed that no fluorine atom is bonded to the carbon atom adjacent to the S atom in Rd ² (not substituted with fluorine). As a result, the anion of the component (d1-2) becomes an appropriately weak acid anion, and the quenching ability of the component (D) is improved.
Rd ² is preferably a chain alkyl group that may have a substituent or an aliphatic cyclic group that may have a substituent; More preferably, it is a formula group.

The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms.
The aliphatic cyclic group includes a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent); one or more camphor More preferably, it is a group from which a hydrogen atom is removed.

The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group) of Rd ¹ of the above formula (d1-1). , chain alkyl group) may be included.

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

...Cation moiety In the formula (d1-2), M ^m+ is an m-valent onium cation, and is the same as M ^m+ in the above formula (d1-1).
Component (d1-2) may be used alone or in combination of two or more.

{(d1-3) component}
...Anion moiety In formula (d1-3), Rd ³ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group, and examples thereof include those similar to R' ²⁰¹ above, and it is preferably a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferred, and the same fluorinated alkyl group as Rd ¹ above is more preferred.

In formula (d1-3), Rd ⁴ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkyl group which may have a substituent. It is an alkenyl group, and the same groups as R' ²⁰¹ above can be mentioned.
Among these, preferred are alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups that may have substituents.
The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group. group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. A portion of the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with 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 group, ethoxy group, n-propoxy group, iso-propoxy group, Examples include n-butoxy group and tert-butoxy group. Among them, methoxy group and ethoxy group are preferred.

Examples of the alkenyl group for Rd ⁴ include the same alkenyl groups as for R' ²⁰¹ above, and vinyl group, propenyl group (allyl group), 1-methylpropenyl group, and 2-methylpropenyl group are preferable. 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.

Examples of the cyclic group in Rd ⁴ include the same cyclic groups as in R' ²⁰¹ above, including one or more cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group from which a hydrogen atom has been removed, or an aromatic group such as a phenyl group or a naphthyl group is preferable. When Rd ⁴ is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in good lithography properties. Further, when Rd ⁴ is an aromatic group, the resist composition has excellent light absorption efficiency and good sensitivity and lithography properties in lithography using EUV or the like as an exposure light source.

In formula (d1-3), Yd ¹ is a single bond or a divalent linking group.
The divalent linking group in Yd ¹ is not particularly limited, but includes divalent hydrocarbon groups that may have substituents (aliphatic hydrocarbon groups, aromatic hydrocarbon groups), divalent hydrocarbon groups containing heteroatoms, etc. Examples include linking groups such as These are the divalent hydrocarbon group which may have a substituent, the divalent linking group for R ⁰¹ in formula (a0-1) above, and the divalent linking group containing a hetero atom, respectively. Examples include those similar to the valent linking group.
Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

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

...Cation moiety In formula (d1-3), M ^m+ is an m-valent onium cation, and is the same as M ^m+ in formula (d1-1) above.
Component (d1-3) may be used alone or in combination of two or more.

As the component (D1), any one of the components (d1-1) to (d1-3) above may be used alone, or two or more thereof may be used in combination.
In the resist composition of the present embodiment, the component (D1) preferably contains the component (d1-1) described above.
When the resist composition contains component (D1), the content of component (D1) in the resist composition is preferably 0.5 to 15 parts by mass, and 1 to 15 parts by mass, based on 100 parts by mass of component (A1). It is more preferably 10 parts by weight, and even more preferably 2 to 9 parts by weight.
When the content of component (D1) is at least the preferable lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained. On the other hand, when it is below the upper limit, sensitivity can be maintained well and throughput is also excellent.

Of the entire component (D) contained in the resist composition of the present embodiment, the content of component (d1-1) is preferably 50% by mass or more, more preferably 70% by mass or more, It is more preferably 90% by mass or more, and component (D) may consist only of compound (d1-1) component.

(D1) Method for producing component:
The method for producing the components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods.
Furthermore, the method for producing component (d1-3) is not particularly limited, and is produced, for example, in the same manner as the method described in US2012-0149916.

- Regarding component (D2) Component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not correspond to component (D1) above.
The component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not fall under the component (D1), and any known components may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are particularly preferred.
Aliphatic amines are amines having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of aliphatic amines include amines (alkyl amines or alkyl alcohol amines) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkyl amines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; 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, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, tri- Examples include alkyl alcohol amines such as isopropanolamine, 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 the cyclic amine include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, specifically, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5 .4.0]-7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane, and the like.

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

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

Among the above, component (D2) is preferably an alkylamine, more preferably a trialkylamine having 5 to 10 carbon atoms.

Component (D2) may be used alone or in combination of two or more.
When the resist composition contains component (D2), the content of component (D2) in the resist composition is preferably 0.01 to 5 parts by mass, and 0.01 to 5 parts by mass, based on 100 parts by mass of component (A1). It is more preferably 1 to 5 parts by weight, and even more preferably 0.5 to 5 parts by weight.
When the content of the component (D2) is at least the preferable lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained. On the other hand, when it is below the upper limit, sensitivity can be maintained well and throughput is also excellent.

<<At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids and derivatives thereof>>
The resist composition of this embodiment contains organic carboxylic acids, phosphorus oxoacids, and derivatives thereof as optional components for the purpose of preventing sensitivity deterioration, improving resist pattern shape, storage stability over time, etc. At least one compound (E) selected from the group consisting of (hereinafter referred to as "component (E)") can be contained.
Specific examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, among which salicylic acid is preferred.
Examples of the phosphorus oxoacid include phosphoric acid, phosphonic acid, and phosphinic acid, and among these, phosphonic acid is particularly preferred.

In the resist composition of the present embodiment, one kind of component (E) may be used alone, or two or more kinds may be used in combination.
When the resist composition contains component (E), the content of component (E) is preferably 0.01 to 5 parts by mass, and 0.05 to 3 parts by mass, based on 100 parts by mass of component (A1). is more preferable. By setting it within the above range, the lithography characteristics are further improved.

≪Fluorine additive component (F)≫
The resist composition of this embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") as a hydrophobic resin. The component (F) is used to impart water repellency to the resist film, and by being used as a resin separate from the component (A1), the lithography properties can be improved.
The component (F) is described, for example, in JP-A No. 2010-002870, JP-A No. 2010-032994, JP-A No. 2010-277043, JP-A No. 2011-13569, and JP-A No. 2011-128226. The following fluorine-containing polymer compounds can be used.
More specifically, component (F) includes a polymer having a structural unit (f1) represented by the following general formula (f1-1). This polymer includes a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the above structural unit (a1); ; It is preferable that it is a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1), and the structural unit (f1) and the structural unit (a1) More preferably, it is a copolymer with. Here, the structural unit (a1) copolymerized with the structural unit (f1) is a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, 1-methyl-1-adamantyl ( A structural unit derived from meth)acrylate is preferred, and a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate is more preferred.

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

In 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 preferable.
In formula (f1-1), the halogen atoms of Rf ¹⁰² and Rf ¹⁰³ are preferably fluorine atoms. Examples of the alkyl group having 1 to 5 carbon atoms for Rf ¹⁰² and Rf ¹⁰³ include those similar to the alkyl group having 1 to 5 carbon atoms for R above, and methyl group or ethyl group is preferable. Specifically, the halogenated alkyl group having 1 to 5 carbon atoms in Rf ¹⁰² and Rf ¹⁰³ includes a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. can be mentioned. The halogen atom is preferably a fluorine atom. Among these, Rf ¹⁰² and Rf ¹⁰³ are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom. .
In formula (f1-1), nf ¹ is an integer of 0 to 5, preferably 0 to 3, and more preferably 1 or 2.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms. More preferably, the number of carbon atoms is 1 to 10, particularly preferred.
Further, in the hydrocarbon group containing a fluorine atom, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and 60% or more are fluorinated. It is particularly preferable that the resist be fluorinated because it increases the hydrophobicity of the resist film during immersion exposure.
Among these, Rf ¹⁰¹ is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, such as trifluoromethyl group, -CH ₂ -CF ₃ , -CH ₂ -CF ₂ -CF ₃ , -CH(CF ₃ ) ₂ , -CH ₂ -CH ₂ -CF ₃ and -CH ₂ -CH ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₃ are particularly preferred.

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

In the resist composition of the present embodiment, one kind of component (F) may be used alone, or two or more kinds may be used in combination.
When the resist composition contains component (F), the content of component (F) is preferably 0.5 to 10 parts by mass, and preferably 1 to 10 parts by mass, based on 100 parts by mass of component (A1). It is more preferable that it is part.

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

Further, as the component (S), a mixed solvent of PGMEA and a polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent.
As component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5.
The amount of component (S) to be used is not particularly limited, and is appropriately set at a concentration that allows coating on a substrate, etc., depending on the thickness of the coating film. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by weight, preferably 0.2 to 15% by weight.

In the resist composition of this embodiment, after the resist material is dissolved in the component (S), impurities and the like may be removed using a porous polyimide membrane, a porous polyamide-imide membrane, or the like. For example, the resist composition may be filtered using a filter made of a porous polyimide membrane, a filter made of a porous polyamide-imide membrane, a filter made of a porous polyimide membrane and a porous polyamide-imide membrane, or the like. Examples of the polyimide porous membrane and the polyamideimide porous membrane include those described in JP-A No. 2016-155121.

The resist composition of the present embodiment described above contains a resin component (A1) having a structural unit (a0) represented by the general formula (a0-1). This makes it possible to achieve higher sensitivity and further improve lithography characteristics such as uniformity of pattern dimensions. The reason for this effect is presumed to be as follows.
The structural unit (a0) has an acid generating group that generates an acid upon exposure to light via an aromatic hydrocarbon group (R ⁰⁰ ) which may have a substituent on one side chain, and On the other hand, it has an acid-decomposable site.
Thus, in the structural unit (a0), an anion moiety which is an acid generating group is incorporated into the resin component (A1). Furthermore, since the acid-generating groups are uniformly distributed throughout the resist film, the acid generated by exposure uniformly acts on acid-decomposable sites in the resist film.
In addition, since the structural unit (a0) has an aromatic hydrocarbon group (R ⁰⁰ ) which may have a substituent at the link between the main chain and the acid generating group, the unexposed part of the resist film The effect of inhibiting dissolution is enhanced.
It is presumed that the above-mentioned effects work synergistically to achieve higher sensitivity and further improvement of lithography characteristics such as uniformity of pattern dimensions.

(Resist pattern formation method)
The resist pattern forming method according to the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention, and exposing the resist film to light. This method includes a step of developing the exposed resist film to form a resist pattern.
One embodiment of such a resist pattern forming method includes, for example, a resist pattern forming method performed as follows.

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

After the development process, preferably a rinsing process is performed. For the rinsing treatment, in the case of an alkaline development process, water rinsing using pure water is preferable, and in the case of a solvent development process, it is preferable to use a rinsing liquid containing an organic solvent.
In the case of a solvent development process, after the development treatment or rinsing treatment, a treatment may be performed to remove the developer or rinse agent adhering to the pattern using a supercritical fluid.
After development or rinsing, drying is performed. In some cases, a bake process (post-bake) may be performed after the development process.

The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and substrates on which predetermined wiring patterns are formed. More specifically, examples include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. As the material for the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used.

The wavelength used for exposure is not particularly limited, and may include ArF excimer laser, KrF excimer laser, _F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. It can be done using radiation.
The resist pattern forming method of this embodiment is a method useful in a case where the resist film is exposed to EUV (extreme ultraviolet rays) or EB (electron beam) in the step of exposing the resist film.

The method of exposing the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion lithography.
In immersion exposure, the space between the resist film and the lowest lens of the exposure device is filled in advance with a solvent (immersion medium) that has a refractive index greater than that of air, and exposure (immersion exposure) is performed in that state. This is an exposure method.
The immersion medium is preferably a solvent having a refractive index greater than that of air and less than the refractive index of the resist film to be exposed, such as water, fluorine-based inert liquid, silicone-based solvent, carbonized Examples include hydrogen-based solvents.
Water is preferably used as the immersion medium.

Examples of the alkaline developer used in the alkaline development process include a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for development in the solvent development process may be any organic solvent as long as it can dissolve component (A1) (component (A1) before exposure), and may be selected from known organic solvents. You can choose as appropriate. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, hydrocarbon solvents, and the like.

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

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

Known additives can be added to the organic developer as necessary. Examples of such additives include surfactants. Although the surfactant is not particularly limited, for example, ionic or nonionic fluorine-based and/or silicon-based surfactants can be used.

The development process can be carried out by a known development method, such as a method in which the support is immersed in a developer for a certain period of time (dipping method), a method in which the support is heaped up on the surface of the support by surface tension, and then left for a certain period of time. (paddle method), spraying the developer onto the surface of the support (spray method), and applying the developer onto the rotating support while scanning the developer application nozzle at a constant speed. Examples include a method of continuous dispensing (dynamic dispensing method), etc.

As the organic solvent contained in the rinsing liquid used for rinsing after development in the solvent development process, for example, among the organic solvents listed as organic solvents used in the organic developer, those that do not easily dissolve the resist pattern are appropriately selected. It can be used as Generally, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used.
Any one type of these organic solvents may be used alone, or two or more types may be used in combination. Further, it may be used in combination with an organic solvent other than those mentioned above or water.

The rinsing process (cleaning process) using a rinsing liquid can be performed by a known rinsing method. Examples of the rinsing method include a method of continuously applying a rinsing liquid onto a support rotating at a constant speed (rotary coating method), a method of immersing the support in a rinsing liquid for a certain period of time (dipping method), Examples include a method of spraying a rinsing liquid onto the surface of the support (spray method).

According to the resist pattern forming method of the present embodiment described above, since the above-described resist composition is used, it is possible to achieve high sensitivity and form a resist pattern with good lithography characteristics such as uniformity of pattern dimensions. be able to.

The resist composition of the embodiment described above, and various materials used in the pattern forming method of the embodiment described above (e.g., resist solvent, developer, rinse solution, composition for forming an antireflective film, composition for forming a top coat) It is preferable that the material does not contain impurities such as metals, metal salts containing halogens, acids, alkalis, components containing sulfur atoms, or phosphorus atoms. Here, examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. can. The content of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and substantially free of impurities (parts per trillion). most preferably below the detection limit).

(Compound)
The compound according to the third aspect of the present invention is a compound represented by the following general formula (a0-m1) (hereinafter also referred to as "compound (a0)").

In the above formula (a0-m1), R ⁰¹ , R ⁰² , Y ⁰⁰ , R ⁰⁰ , Y ⁰¹ , V ⁰¹ , R ⁰³ , M ^m+ and m are R ⁰¹ in the above general formula (a0-1), The same as R ⁰² , Y ⁰⁰ , R ⁰⁰ , Y ⁰¹ , V ⁰¹ , R ⁰³ , M ^m+ and m, respectively.

Suitable examples of the compound (a0) include compounds in which R ⁰² in the formula (a0-m1) is an acid-dissociable group represented by the above-mentioned general formula (a1-r-2).
Alternatively, as the compound (a0), a compound in which R ⁰² in the formula (a0-m1) is an acid-dissociable group represented by the above-mentioned general formula (a1-r-4) is preferably mentioned. It will be done.
Alternatively, in the compound (a0), R ⁰⁰ in the formula (a0-m1) is an aromatic hydrocarbon group having a substituent, and the substituent is composed of a halogen atom, an alkyl group, and an alkoxy group. Preferred examples include one or more compounds selected from the group.
Alternatively, suitable examples of the compound (a0) include compounds in which R ⁰⁰ in the formula (a0-m1) is a group represented by the above-mentioned general formula (R ⁰⁰ -1).

Specific examples of the compound (a0) are listed below, but the invention is not limited thereto.
M ^m+ is an m-valent onium cation, preferably a cation represented by the above general formula (ca-1).

[Method for producing compound (a0)]
Compound (a0) of this embodiment can be produced by combining known methods.
One embodiment of the method for producing compound (a0) includes a production method including the following steps (I) to (IV).

Step (I):
In step (I), the following general formula (a0- A compound represented by m0-3) is obtained.

[In the formula, Xh is a halogen atom. R ⁰¹ is a divalent linking group or a single bond. R ⁰² is an acid dissociable group. ]

R ⁰¹ and R ⁰² in the above reaction formula are the same as the explanations for R ⁰¹ and R ⁰² described above. Xh is a halogen atom, preferably a chlorine atom.
The reaction temperature conditions in step (I) are not particularly limited, and are, for example, about 0 to 120°C.
The reaction time of step (I) is not particularly limited, and is, for example, about 1 to 12 hours.

Examples of the reaction solvent used in step (I) include dichloromethane (CH ₂ Cl ₂ ), dichloroethane, chloroform, tetrahydrofuran (THF), N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide. , dimethyl sulfoxide and the like.

In the reaction of step (I), a basic catalyst may be selected and used as appropriate. Examples of basic catalysts include tertiary amines such as trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine, dimethylaminopyridine, and pyrrolidinopyridine; diazabicyclononene (DBN), and diazabicycloundecene. (DBU), etc.

After the reaction in step (I) is completed, the compound in the reaction solution may be isolated and purified. Conventionally known methods can be used for isolation and purification.

Step (II):
In step (II), a compound represented by the following general formula (a0-m0-4) is obtained by reacting the compound represented by the following general formula (a0-m0-3) with an aldehyde.

[In the formula, R ⁰² is an acid dissociable group. R ⁰¹ is a divalent linking group or a single bond. Y ^00a is a group derived from aldehyde. ]

R ⁰¹ and R ⁰² in the above reaction formula are the same as the explanations for R ⁰¹ and R ⁰² described above. Y ^00a is a group derived from aldehyde, such as a group derived from formaldehyde (-CH ₂ -OH).
The reaction temperature conditions in step (II) are not particularly limited, and are, for example, about 0 to 120°C.
The reaction time of step (II) is not particularly limited, and is, for example, about 1 to 24 hours.

Examples of the reaction solvent used in step (II) include toluene, dichloromethane (CH ₂ Cl ₂ ), dichloroethane, chloroform, tetrahydrofuran (THF), N,N-dimethylformamide, acetonitrile, propionitrile, N,N'- Examples include dimethylacetamide, dimethylsulfoxide, and the like.

In the reaction of step (II), a basic catalyst may be selected and used as appropriate. Examples of the basic catalyst include tertiary amines such as potassium tert-butoxide, trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine, dimethylaminopyridine, and pyrrolidinopyridine; diazabicyclooctane (DABCO), Examples include diazabicyclononene (DBN) and diazabicycloundecene (DBU).

After the reaction in step (II) is completed, the compound in the reaction solution may be isolated and purified. Conventionally known methods can be used for isolation and purification.

Step (III):
In step (III), the following general formula (a0- A compound represented by m0-7) is obtained.

[Wherein, V ⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. R ⁰³ is a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. M ^m+ is an m-valent onium cation. m is an integer of 1 or more. R ⁰⁰ is an aromatic hydrocarbon group which may have a substituent. Y ^01a and Y ^01b are groups that form Y ⁰¹ after the reaction in step (III). Y ⁰¹ is a divalent linking group or a single bond containing an oxygen atom. Y ⁰¹ and V ⁰¹ never become a single bond at the same time. Y ^00b is a group that is condensed with Y ^00a to form Y ⁰⁰ . Y ⁰⁰ is a divalent linking group or a single bond. ]

V ⁰¹ , R ⁰³ , M ^m+ , m, R ⁰⁰ , Y ⁰¹ and Y ⁰⁰ in the above reaction formula are the same as for V ⁰¹ , R ⁰³ , M ^m+ , m, R ⁰⁰ , Y ⁰¹ and Y ⁰⁰ described above. Same as description.
Y ^01a and Y ^01b are groups that form Y ⁰¹ after the reaction in step (III). For example, Y ^01a is a hydroxy group (-OH), Y ^01b is a carboxy group (-C(=O)-OH), and Y ⁰¹ forms an ester bond (-C(=O)-O-). There are cases where this is the case.
Y ^00b is a group that is condensed with Y ^00a to form Y ⁰⁰ . For example, Y ^00b is a hydroxy group (-OH), Y ^00a is a formaldehyde-derived group (-CH ₂ -OH), and Y ⁰⁰ forms -CH ₂ -O-.
The reaction temperature conditions in step (III) are not particularly limited, and are, for example, about 0 to 50°C.
The reaction time of step (III) is not particularly limited, and is, for example, about 1 to 12 hours.

Examples of the reaction solvent used in step (III) include dichloromethane, dichloroethane, chloroform, diethyl ether, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, and dimethylsulfoxide. .

In the reaction of step (III), a condensing agent is appropriately selected and used. Examples of the condensing agent include dicyclohexylcarbodiimide, diisopropylcarbodiimide (DIC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and carbonyldiimidazole (CDI).

In the reaction of step (III), a basic catalyst may be selected and used as appropriate. Examples of basic catalysts include tertiary amines such as trimethylamine, triethylamine, and tributylamine, aromatic amines such as pyridine, pyrrolidinopyridine, and 4-(dimethylamino)pyridine (DMAP), and diazabicyclononene (DBN). ), diazabicycloundecene (DBU), and the like.

After the reaction in step (III) is completed, the compound in the reaction solution may be isolated and purified. Conventionally known methods can be used for isolation and purification.

Process (IV):
In step (IV), a compound represented by the following general formula (a0-m0-4) and a compound represented by the following general formula (a0-m0-7) are reacted to form the desired general formula ( A compound represented by a0-m1) is obtained.

[In the formula, R ⁰² is an acid dissociable group. R ⁰¹ is a divalent linking group or a single bond. Y ^00a is a group derived from aldehyde. Y ^00b is a group that is condensed with Y ^00a to form Y ⁰⁰ . Y ⁰⁰ is a divalent linking group or a single bond. R ⁰⁰ is an aromatic hydrocarbon group which may have a substituent. Y ⁰¹ is a divalent linking group or a single bond containing an oxygen atom. V ⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. Y ⁰¹ and V ⁰¹ never become a single bond at the same time. R ⁰³ is a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. M ^m+ is an m-valent onium cation. m is an integer of 1 or more. ]

R ⁰² , R ⁰¹ , Y ^00a , Y ^00b , Y ⁰⁰ , R ⁰⁰ , Y ⁰¹ , V ⁰¹ , R ⁰³ , M ^m+ and m in the above reaction formula are the same as described above.
The reaction temperature conditions in step (IV) are not particularly limited, and are, for example, about 0 to 50°C.
The reaction time in step (IV) is not particularly limited, and is, for example, about 1 to 12 hours.

Examples of the reaction solvent used in step (IV) include dichloromethane, dichloroethane, chloroform, diethyl ether, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, and dimethylsulfoxide. .

In the reaction of step (IV), a condensing agent is appropriately selected and used. Examples of the condensing agent include dicyclohexylcarbodiimide, diisopropylcarbodiimide (DIC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and carbonyldiimidazole (CDI).

In the reaction of step (IV), a basic catalyst may be selected and used as appropriate. Examples of basic catalysts include tertiary amines such as trimethylamine, triethylamine, and tributylamine, aromatic amines such as pyridine, pyrrolidinopyridine, and 4-(dimethylamino)pyridine (DMAP), and diazabicyclononene (DBN). ), diazabicycloundecene (DBU), and the like.

After completion of step (IV), compound (a0) in the reaction solution may be isolated and purified.
Conventionally known methods can be used for isolation and purification; for example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more of these. can.
The structure of the compound obtained as described above can be determined by ¹ H-nuclear magnetic resonance (NMR) spectroscopy, ¹³ C-NMR spectroscopy, ¹⁹ F-NMR spectroscopy, infrared absorption (IR) spectroscopy, mass spectrometry ( It can be confirmed by general organic analysis methods such as MS) method, elemental analysis method, and X-ray crystal diffraction method.

The compound of this embodiment can be used as a raw material monomer for a polymer compound according to the fourth aspect described below.

(polymer compound)
A fourth aspect of the present invention is a polymer compound having a structural unit represented by the following general formula (a0-1).

In addition to the structural unit represented by the general formula (a0-1), the polymer compound according to the fourth aspect further includes a structural unit represented by the following general formula (a10-1). Preferred examples include:

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ^x1 is a divalent linking group or a single bond. Wa ^x1 is an aromatic hydrocarbon group which may have a substituent. n _ax1 is an integer of 1 or more. ]

The structural unit represented by the general formula (a0-1) is a structural unit derived from the compound represented by the general formula (a0-m1), and is the same as the structural unit (a0) described above.
The structural unit represented by the general formula (a10-1) is the same as the structural unit (a10) described above.
The polymer compound according to the fourth aspect is the same as the explanation for component (A1) above.
The polymer compound according to the fourth aspect, that is, the polymer compound having a structural unit represented by general formula (a0-1), can be used as a base material component of the resist composition according to the first aspect. . In addition, a polymer compound having a structural unit represented by the general formula (a0-1) and a structural unit represented by the general formula (a10-1) is particularly useful as a resist material for lithography that exposes EUV or EB. It is useful as a.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Synthesis example of compound>
[Synthesis Example 1: Synthesis of compound (a0-01)]
50.0 g of the following compound (a0-01-2), 500.0 g of dichloromethane, 75.8 g of triethylamine, and 6.1 g of 4-dimethylaminopyridine were charged into a flask, and the following compound (a0-01- 1) 58.7 g was added dropwise and stirred at room temperature for 3 hours. After washing with an aqueous ammonium chloride solution, the organic layer was concentrated to obtain 65.4 g of compound (a0-01-3).

A flask was charged with 50.0 g of the following compound (a0-01-3), 300.0 g of tetrahydrofuran (THF), 300.0 g of water, and 10.7 g of formaldehyde, and 1,4-diazabicyclo[2. 2.2] 181.9 g of octane (DABCO) was added and stirred at 90° C. for 12 hours. After washing with ion-exchanged water, the organic layer was concentrated to obtain 52.6 g of compound (a0-01-4).

50.0 g of the following compound (a0-01-5), 55.1 g of the following compound (a0-01-6), 500.0 g of dichloromethane, and 26.7 g of 1,1'-carbonyldiimidazole (CDI). The mixture was charged into a flask and stirred at room temperature for 3 hours. After washing with ion exchange, the organic layer was concentrated to obtain 65.7 g of compound (a0-01-7).

A flask was charged with 50.0 g of the following compound (a0-01-4), 173.6 g of the following compound (a0-01-7), 500.0 g of dichloromethane, and 47.9 g of diisopropylcarbodiimide (DIC), and the mixture was heated at room temperature. Stirred for 3 hours. Thereafter, after washing with hydrochloric acid, the organic layer was concentrated to obtain 157.8 g of the target compound (a0-01).

The obtained compound (a0-01) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.39 (3H, s), 1.69 (8H, m), 4.61 (2H, s), 5.13 (2H, t), 6.02 (1H, m), 6.59 (1H, m), 7.36 (15H, m), 8.10 (1H, d), 8.21 (1H, d)

[Synthesis Example 2: Synthesis of compound (a0-02)]
The target compound (a0-02) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-02-6) was used instead of compound (a0-01-6).

The obtained compound (a0-02) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.39 (3H, s), 1.69 (8H, m), 4.61 (2H, s), 5.13 (2H, t), 6.02 (1H, m), 6.59 (1H, m), 7.36 (15H, m), 8.21 (2H, s)

[Synthesis Example 3: Synthesis of compound (a0-03)]
The target compound (a0-03) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-03-2) was used instead of compound (a0-01-2).

The obtained compound (a0-03) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.76 (8H, m), 4.61 (2H, s), 5.13 (2H, t), 5.28 (2H, m), 5.89 (1H, m), 6.02 (1H, m), 6.59 (1H, m), 7.36 (15H, m), 8.10 (1H, d), 8. 21 (1H, d)

[Synthesis Example 4: Synthesis of compound (a0-04)]
The target compound (a0-04) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-04-2) was used instead of compound (a0-01-2).

The obtained compound (a0-04) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.54 (6H, s), 4.61 (2H, s), 5.13 (2H, t), 6.02 (1H, m), 6.59 (1H, m), 7.13 (1H, m), 7.30 (2H, m), 7.54 (2H, m), 8.10 (1H, d), 8. 21 (1H, d)

[Synthesis Example 5: Synthesis of compound (a0-05)]
The target compound (a0-05) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-05-5) was used instead of compound (a0-01-5).

The obtained compound (a0-05) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.39 (3H, s), 1.69 (8H, m), 4.61 (2H, s), 5.13 (2H, t), 6.02 (1H, m), 6.59 (1H, m), 6.78 (6H, m), 7.36 (15H, m), 7.65 (5H, m), 8. 10 (1H, d), 8.21 (1H, d)

[Synthesis Example 6: Synthesis of compound (a0-06)]
The target compound (a0-06) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-06-5) was used instead of compound (a0-01-5).

The obtained compound (a0-06) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.39 (3H, s), 1.69 (8H, m), 1.89 (2H, m), 4.23 (2H, t), 4.60 (1H, m), 4.61 (2H, s), 6.02 (1H, m), 6.59 (1H, m), 7.36 (15H, m), 8. 10 (1H, d), 8.21 (1H, d)

[Synthesis Example 7: Synthesis of compound (a0-07)]
The target compound (a0-07) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-07-6) was used instead of compound (a0-01-6).

The obtained compound (a0-07) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.39 (3H, s), 1.69 (8H, m), 4.61 (2H, s), 5.13 (2H, t), 6.02 (1H, m), 6.59 (1H, m), 7.11 (1H, m), 7.36 (15H, m), 7.42 (2H, m), 7. 95 (1H, m)

[Synthesis Example 8: Synthesis of compound (a0-08)]
The target compound (a0-08) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-08-6) was used instead of compound (a0-01-6).

The obtained compound (a0-08) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.39 (3H, s), 1.69 (8H, m), 4.61 (2H, s), 5.13 (2H, t), 6.02 (1H, m), 6.59 (1H, m), 6.76 (1H, d), 7.27 (1H, d), 7.36 (15H, m)

[Synthesis Example 9: Synthesis of compound (a0-09)]
The target compound (a0-09) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-09-6) was used instead of compound (a0-01-6).

The obtained compound (a0-09) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.39 (3H, s), 1.69 (8H, m), 4.61 (2H, s), 5.13 (2H, t), 6.02 (1H, m), 6.59 (1H, m), 7.36 (15H, m), 7.73 (1H, d), 8.03 (1H, d)

[Synthesis Example 10: Synthesis of compound (a0-10)]
The target compound (a0-10) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-10-2) was used instead of compound (a0-01-2).

The obtained compound (a0-10) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.65 (3H, s), 1.65 (2H, m), 1.88 (2H, m), 1.94 (2H, m), 4.61 (2H, s), 5.13 (3H, m), 5.37 (1H, m), 6.02 (1H, m), 6.59 (1H, m), 7. 36 (15H, m), 8.10 (1H, d), 8.21 (1H, d)

[Synthesis Example 11: Synthesis of compound (a0-11)]
The target compound (a0-11) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-11-2) was used instead of compound (a0-01-2).

The obtained compound (a0-11) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.24 (3H, s), 1.65 (2H, m), 1.84 (2H, m), 1.96 (2H, m), 4.61 (2H, s), 5.13 (3H, m), 6.02 (1H, m), 6.59 (1H, m), 7.36 (15H, m), 8. 10 (1H, d), 8.21 (1H, d)

[Synthesis Example 12: Synthesis of compound (a0-12)]
The target compound (a0-12) was obtained in the same manner as in Synthesis Example 1, except that the following compound (a0-12-2) was used instead of compound (a0-01-2).

The obtained compound (a0-12) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.54 (6H, s), 4.61 (2H, s), 5.13 (2H, t), 6.02 (1H, m), 6.59 (1H, m), 7.05 (2H, d), 7.36 (15H, m), 7.60 (2H, d), 8.10 (1H, d), 8. 21 (1H, d)

[Synthesis Example 13: Synthesis of compound (a0-13)]
50.0 g of the following compound (a0-13-2), 500.0 g of dichloromethane, 75.8 g of triethylamine, and 6.1 g of 4-dimethylaminopyridine were charged into a flask, and the following compound (a0-13- 1) 90.5 g was added dropwise and stirred at room temperature for 3 hours. Thereafter, after washing with an aqueous ammonium chloride solution, the organic layer was concentrated to obtain 86.9 g of compound (a0-13-3).

A flask was charged with 50.0 g of the following compound (a0-13-3), 300.0 g of tetrahydrofuran (THF), 300.0 g of water, and 7.8 g of formaldehyde, and 1,4-diazabicyclo[2. 2.2] 132.1 g of octane (DABCO) was added and stirred at 90° C. for 12 hours. After washing with ion-exchanged water, the organic layer was concentrated to obtain 50.8 g of compound (a0-13-4).

A flask was charged with 50.0 g of the following compound (a0-13-4), 132.0 g of the following compound (a0-13-5), 500.0 g of dichloromethane, and 36.5 g of diisopropylcarbodiimide (DIC), and the mixture was heated at room temperature. Stirred for 3 hours. After washing with hydrochloric acid, the organic layer was concentrated to obtain 147.4 g of the target compound (a0-13).
Note that compound (a0-13-5) is the same as the above compound (a0-01-7).

The obtained compound (a0-13) was subjected to NMR measurement, and its structure was identified from the following results.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.39 (3H, s), 1.69 (8H, m), 4.61 (2H, s), 5.11 (2H, s), 5.13 (2H, t), 6.02 (1H, m), 6.59 (1H, m), 7.36 (15H, m), 8.10 (1H, d), 8. 21 (1H, d)

<Example of synthesis of polymer compounds>
[Synthesis of polymer compound (A1-1)]
45.0 g of the following compound (a0-01), 21.0 g of the following compound (m-a10-1pre), and 1.1 g of azobis(isobutyric acid) dimethyl (V-601) as a polymerization initiator were added to methyl ethyl ketone (MEK). ) A dropping solution was prepared by dissolving 90.0 g.
A reaction solution was obtained by adding 90.0 g of MEK to a three-neck flask connected to a thermometer, a reflux tube, and a nitrogen inlet tube, heating it to 85 ° C. under a nitrogen atmosphere, and adding the solution dropwise over 4 hours. Ta.
After the dropwise addition was completed, the resulting reaction solution was stirred at 85° C. for 1 hour. After this, the reaction solution was cooled to room temperature.
Next, the cooled reaction solution was precipitated with 450 g of heptane, and the precipitate was washed.
After washing, the obtained white solid was filtered and dried under reduced pressure overnight to obtain the desired polymer compound (A1-1).

[Synthesis of polymer compounds (A1-2) to (A1-14)]
Polymer compounds (A1-2) to (A1-14) were synthesized in the same manner as in the synthesis of polymer compound (A1-1), except that the monomers used and the amounts thereof were changed.
The aforementioned compounds (a0-02) to (a0-13) were used as monomers for inducing the structural unit (a0).

The structures of the synthesized polymer compounds (A1-1) to (A1-14) are shown below.

The weight average molecular weight (Mw) and molecular weight dispersity (Mw/Mn) of the polymer compounds (A1-1) to (A1-14) were determined by GPC measurement (standard polystyrene conversion).
The copolymerization composition ratio (ratio (mole ratio) of each structural unit in the structural formula) of the polymer compounds (A1-1) to (A1-14) was determined by carbon-13 nuclear magnetic resonance spectrum (600MHz_ ¹³ C-NMR). I asked for it.

Polymer compound (A1-1): weight average molecular weight (Mw) 8000, molecular weight dispersity (Mw/Mn) 1.67, l/m=30/70.
Polymer compound (A1-2): weight average molecular weight (Mw) 8200, molecular weight dispersity (Mw/Mn) 1.72, l/m=30/70.
Polymer compound (A1-3): weight average molecular weight (Mw) 8300, molecular weight dispersity (Mw/Mn) 1.82, l/m=30/70.
Polymer compound (A1-4): Weight average molecular weight (Mw) 7800, molecular weight dispersity (Mw/Mn) 1.69, l/m = 30/70.
Polymer compound (A1-5): weight average molecular weight (Mw) 8100, molecular weight dispersity (Mw/Mn) 1.73, l/m=30/70.
Polymer compound (A1-6): weight average molecular weight (Mw) 8200, molecular weight dispersity (Mw/Mn) 1.77, l/m=30/70.
Polymer compound (A1-7): weight average molecular weight (Mw) 8000, molecular weight dispersity (Mw/Mn) 1.80, l/m=30/70.
Polymer compound (A1-8): weight average molecular weight (Mw) 7800, molecular weight dispersity (Mw/Mn) 1.69, l/m=30/70.
Polymer compound (A1-9): weight average molecular weight (Mw) 7700, molecular weight dispersity (Mw/Mn) 1.68, l/m=30/70.
Polymer compound (A1-10): Weight average molecular weight (Mw) 8300, molecular weight dispersity (Mw/Mn) 1.74, l/m = 30/70.
Polymer compound (A1-11): Weight average molecular weight (Mw) 8200, molecular weight dispersity (Mw/Mn) 1.73, l/m = 30/70.
Polymer compound (A1-12): Weight average molecular weight (Mw) 8400, molecular weight dispersity (Mw/Mn) 1.75, l/m = 30/70.
Polymer compound (A1-13): weight average molecular weight (Mw) 8100, molecular weight dispersity (Mw/Mn) 1.72, l/m=30/70.
Polymer compound (A1-14): Weight average molecular weight (Mw) 7800, molecular weight dispersity (Mw/Mn) 1.69, l/m/n = 30/50/20.

<Preparation of resist composition>
(Examples 1 to 17, Comparative Examples 1 to 3)
Each component shown in Table 1 was mixed and dissolved to prepare a resist composition for each example.

In Table 1, each abbreviation has the following meaning. The numerical value in [ ] is the blending amount (parts by mass; solid content equivalent).

(A)-1 to (A)-14: The above-mentioned polymer compounds (A1-1) to (A1-14).

(A)-15: The following polymer compound (A2-1). Weight average molecular weight (Mw) 8400, molecular weight dispersity (Mw/Mn) 1.84, l/m=30/70.
(A)-16: The following polymer compound (A2-2). Weight average molecular weight (Mw) 7900, molecular weight dispersity (Mw/Mn) 1.69, l/m=30/70.
(A)-17: The following polymer compound (A2-3). Weight average molecular weight (Mw) 8300, molecular weight dispersity (Mw/Mn) 1.84, l/m=70/30.
The weight average molecular weight (Mw) is a standard polystyrene equivalent weight average molecular weight determined by GPC measurement. The copolymerization composition ratio (ratio (mole ratio) of each structural unit in the structural formula) was determined by ¹³ C-NMR.

(B)-1: An acid generator consisting of the following compound (B-1).
(B)-2: An acid generator consisting of the following compound (B-2).

(D)-1: An acid diffusion control agent consisting of the following compound (D1-1).
(D)-2: An acid diffusion control agent consisting of the following compound (D1-2).

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

<Formation of resist pattern>
Process of forming resist film:
The resist composition of each example was applied using a spinner onto an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS), and pre-baked (PAB) at a temperature of 110°C for 60 seconds on a hot plate. By processing and drying, a resist film with a thickness of 50 nm was formed.

Step of exposing resist film:
Next, using an electron beam lithography system JEOL-JBX-9300FS (manufactured by JEOL Ltd.), the resist film was subjected to a target size of 32 nm diameter holes at equal intervals (pitch 64 nm) at an acceleration voltage of 100 kV. Drawing (exposure) was performed to form an arranged contact hole pattern (hereinafter referred to as "CH pattern").
Thereafter, post-exposure heating (PEB) treatment was performed at 110° C. for 60 seconds.

Step of developing the resist film after exposure:
Next, alkaline development was performed at 23° C. for 60 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.).
Thereafter, water rinsing was performed for 15 seconds using pure water.
As a result, a CH pattern was formed in which holes with a diameter of 32 nm were arranged at equal intervals (pitch 64 nm).

[Evaluation of optimal exposure amount (Eop)]
The optimal exposure amount Eop (μC/cm ² ) at which a CH pattern of the target size is formed by the above <Formation of resist pattern> was determined. The results are shown in Table 2 as "Eop (μC/cm ² )".

[Evaluation of in-plane uniformity (CDU) of pattern dimensions]
The CH pattern formed in the above <Formation of resist pattern> was observed from above the CH pattern using a length measurement SEM (scanning electron microscope, acceleration voltage 500V, product name: CG5000, manufactured by Hitachi High-Technologies). The hole diameter (nm) of the hole was measured. Then, the triple value (3σ) of the standard deviation (σ) calculated from the measurement results was determined. The results are shown in Table 2 as "CDU (nm)".
The smaller the 3σ value obtained in this way, the higher the uniformity of the dimensions (CD) of the plurality of holes formed in the resist film.

From the results shown in Table 2, it can be confirmed that the resist compositions of Examples 1 to 17 have increased sensitivity and better CDU than the resist compositions of Comparative Examples 1 to 3.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other changes to the configuration are possible without departing from the spirit of the invention. The invention is not limited by the foregoing description, but only by the scope of the claims appended hereto.

Claims

A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid,
Contains a resin component (A1) whose solubility in a developer changes due to the action of an acid,
The resin component (A1) is a resist composition having a structural unit (a0) represented by the following general formula (a0-1).

[In the formula, R 01 is a divalent linking group or a single bond. R 02 is an acid dissociable group. Y 00 is a divalent linking group or a single bond. R 00 is an aromatic hydrocarbon group which may have a substituent. Y 01 is a divalent linking group or a single bond containing an oxygen atom. V 01 is a single bond, an alkylene group or a fluorinated alkylene group. R 03 is a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. M m+ is an m-valent onium cation. m is an integer of 1 or more. Y 01 and V 01 never become a single bond at the same time. ]
The resist composition according to claim 1, wherein R 02 in the general formula (a0-1) is an acid-dissociable group represented by the following general formula (a1-r-2).

[In the formula, Ra' 4 to Ra' 6 are each a hydrocarbon group, and Ra' 5 and Ra' 6 may be bonded to each other to form a ring. * represents a bond with the oxygen atom bonded to R 02 in the general formula (a0-1). ]
The resist composition according to claim 1, wherein R 02 in the general formula (a0-1) is an acid-dissociable group represented by the following general formula (a1-r-4).

[In the formula, Ra' 10 is a hydrocarbon 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 hydrocarbon group. Ra' 10 and Ra' 11a or Ra' 11b may be bonded to each other to form a ring. Ra' 11a or Ra' 11b and Ra' 12 may be bonded to each other to form a ring. * represents a bond with the oxygen atom bonded to R 02 in the general formula (a0-1). ]
R 00 in the general formula (a0-1) is an aromatic hydrocarbon group having a substituent, and the substituent is one or more types selected from the group consisting of a halogen atom, an alkyl group, and an alkoxy group. The resist composition according to claim 1.
The resist composition according to claim 1, wherein R 00 in the general formula (a0-1) is a group represented by the following general formula (R 00 -1).

[In the formula, R a1 and R a2 each independently represent a halogen atom, an alkyl group, or an alkoxy group. m0 is an integer from 0 to 2. 0≦n1≦m0×2+2. 0≦n2≦4. 0≦n1+n2≦m0×2+4. Either *11 or *12 represents a bond with Y 00 in the general formula (a0-1). Either *21 or *22 represents a bond with Y 01 in the general formula (a0-1). ]
The resist composition according to claim 1, wherein the resin component (A1) further has a structural unit (a10) 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. Ya x1 is a divalent linking group or a single bond. Wa x1 is an aromatic hydrocarbon group which may have a substituent. n ax1 is an integer of 1 or more. ]
The resist composition according to claim 1, further comprising an acid generator component (B) that generates acid upon exposure.
A step of forming a resist film on a support using the resist composition according to any one of claims 1 to 7, a step of exposing the resist film, and a step of developing the resist film after the exposure. A resist pattern forming method comprising a step of forming a resist pattern.
The resist pattern forming method according to claim 8, wherein in the step of exposing the resist film, the resist film is exposed to EUV (extreme ultraviolet light) or EB (electron beam).
A compound represented by the following general formula (a0-m1).

[In the formula, R 01 is a divalent linking group or a single bond. R 02 is an acid dissociable group. Y 00 is a divalent linking group or a single bond. R 00 is an aromatic hydrocarbon group which may have a substituent. Y 01 is a divalent linking group or a single bond containing an oxygen atom. V 01 is a single bond, an alkylene group or a fluorinated alkylene group. R 03 is a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. M m+ is an m-valent onium cation. m is an integer of 1 or more. Y 01 and V 01 never become a single bond at the same time. ]
A polymer compound having a structural unit represented by the following general formula (a0-1).

[In the formula, R 01 is a divalent linking group or a single bond. R 02 is an acid dissociable group. Y 00 is a divalent linking group or a single bond. R 00 is an aromatic hydrocarbon group which may have a substituent. Y 01 is a divalent linking group or a single bond containing an oxygen atom. V 01 is a single bond, an alkylene group or a fluorinated alkylene group. R 03 is a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. M m+ is an m-valent onium cation. m is an integer of 1 or more. Y 01 and V 01 never become a single bond at the same time. ]
The polymer compound according to claim 11, further comprising a structural 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. Ya x1 is a divalent linking group or a single bond. Wa x1 is an aromatic hydrocarbon group which may have a substituent. n ax1 is an integer of 1 or more. ]