WO2024048462A1

WO2024048462A1 - Actinic-ray-sensitive or radiation-sensitive resin composition, resist film, pattern formation method, method for producing electronic device, and polymer

Info

Publication number: WO2024048462A1
Application number: PCT/JP2023/030782
Authority: WO
Inventors: 洋平石地; 智美高橋; 健志川端; 研由後藤
Original assignee: 富士フイルム株式会社
Priority date: 2022-08-31
Filing date: 2023-08-25
Publication date: 2024-03-07

Abstract

The present invention provides an actinic-ray-sensitive or radiation-sensitive resin composition comprising (A) an onium salt compound and (B) a polymer which has a repeating unit including an acid group having an acidic proton and in which the main chain breaks down at irradiation with actinic rays or radioactive rays. The polymer has a repeating unit represented by a specific general formula. The present invention also provides: a resist film; a pattern formation method; a method for producing an electronic device, the method including the pattern formation method; and a polymer useful for the actinic-ray-sensitive or radiation-sensitive resin composition.

Description

Actinic ray-sensitive or radiation-sensitive resin composition, resist film, pattern forming method, electronic device manufacturing method, and polymer

The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition, an actinic ray-sensitive or radiation-sensitive film, a pattern forming method, an electronic device manufacturing method, and a polymer.

After resists for KrF excimer laser (248 nm), pattern forming methods using chemical amplification have been used to compensate for the decrease in sensitivity due to light absorption. For example, in a positive chemical amplification method, first, a photoacid generator contained in an exposed area is decomposed by light irradiation to generate acid. Then, in the post-exposure bake (PEB) process, etc., the catalytic action of the generated acid converts the alkali-insoluble groups of the resin contained in the actinic ray-sensitive or radiation-sensitive resin composition into alkali-soluble groups. The solubility in the developer is changed by, for example, changing to a base. Thereafter, development is performed using, for example, a basic aqueous solution. Thereby, the exposed portion is removed and a desired pattern is obtained.
In order to miniaturize semiconductor devices, the wavelength of exposure light sources has become shorter and the numerical aperture (NA) of projection lenses has become higher.Currently, exposure machines using ArF excimer lasers with a wavelength of 193 nm as light sources have been developed. ing. Furthermore, recently, a pattern forming method using extreme ultraviolet (EUV) light and electron beam (EB) as a light source is also being considered.
Under these current circumstances, various configurations have been proposed as actinic ray-sensitive or radiation-sensitive resin compositions.

For example, Patent Document 1 describes a polymer that has a repeating unit containing a phenolic hydroxyl group, and whose main chain can be cut by electron beam irradiation, resulting in a decrease in molecular weight.

Japanese Patent Application Publication No. 2020-16699

The present inventors prepared and studied an actinic ray-sensitive or radiation-sensitive resin composition containing a predetermined polymer with reference to Patent Document 1, and found that the sensitivity did not meet the recently required level. It became clear that there was room for further improvement. It was also revealed that the pattern formed by the above composition had poor LWR (line width roughness) performance, especially in the formation of ultra-fine patterns, and there was room for further improvement.

Therefore, the present invention has been developed to provide an ultra-fine pattern (for example, a line-and-space pattern with a line width of 15 nm or less, a hole pattern with a hole diameter of 15 nm or less, etc.), which can form a pattern with excellent sensitivity and LWR performance. An object of the present invention is to provide an actinic ray-sensitive or radiation-sensitive resin composition.
Another object of the present invention is to provide a resist film, a pattern forming method, and an electronic device manufacturing method using the actinic ray-sensitive or radiation-sensitive resin composition.
Another object of the present invention is to provide a polymer useful for the actinic ray-sensitive or radiation-sensitive resin composition.

The present inventors have discovered that the above problem can be solved by the following configuration.

[1]
(A) an onium salt compound;
(B) a polymer having a repeating unit containing an acidic group having an acidic proton and whose main chain decomposes upon irradiation with actinic rays or radiation;
The above polymer has a repeating unit represented by the following general formula (1),
The above acidic group is a phenolic hydroxyl group, a carboxyl group, -SO ₂ NHR ^N (R ^N is a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group) , represents a cyano group), an amide group, a carbonylimide group, a sulfonylimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O)NHSO ₂ R ^P (R ^P is an alkyl group or an aryl group).An actinic ray-sensitive or radiation-sensitive resin composition.

In general formula (1),
Y represents a hydrogen atom or a hydrocarbon group.
A ² represents an aromatic ring group having an electron donating group. However, the electron donating group does not correspond to the acidic group.

[2]
The actinic ray-sensitive or radiation-sensitive resin composition according to [1], wherein the polymer has a repeating unit represented by the following general formula (2).

In general formula (2),
X represents a halogen atom.
L ¹ represents -O- or -NR ¹ -. R ¹ represents a hydrogen atom or an organic group.
A ¹ represents a hydrogen atom or an organic group.
R ⁰ represents a hydrogen atom or an organic group. R ⁰ may be linked with A ¹ or R ¹ to form a ring.

[3]
The sensitizing activity according to [1] or [2], wherein the polymer contains a repeating unit represented by the following general formula (1-2) and a repeating unit represented by the following general formula (2-2). Photosensitive or radiation sensitive resin composition.

In general formula (1-2),
Y represents a hydrogen atom or a hydrocarbon group.
R ² represents an acidic group having the above acidic proton. When a plurality of R ^2s exist, the plurality of R ^2s may be the same or different.
R ³ represents an electron donating group. When a plurality of R ^3s exist, the plurality of R ^3s may be the same or different. However, the electron donating group does not correspond to the acidic group.
L ² represents a single bond or a divalent linking group.
m represents an integer from 1 to 4.
n represents an integer from 1 to 4. However, 1≦m+n≦5 is satisfied.

In general formula (2-2),
X represents a halogen atom.
A ¹ represents a hydrogen atom or an organic group.
R ⁰ represents a hydrogen atom or an organic group. R ⁰ may be connected to A ¹ to form a ring.

[4]
According to any one of [1] to [3], the electron-donating group is at least one group selected from an alkyl group, an alkoxy group, an alkylthio group, a dialkylamino group, and a monoalkylamino group. Actinic ray-sensitive or radiation-sensitive resin composition.

[5]
Any one of [1] to [4], wherein the content of the onium salt compound is 0.1 to 20% by mass based on the total solid content of the actinic ray-sensitive or radiation-sensitive resin composition. The actinic ray-sensitive or radiation-sensitive resin composition described in 2.

[6]
A polymer having a repeating unit containing an acidic group having an acidic proton, comprising a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2),
The above acidic group is a phenolic hydroxyl group, a carboxyl group, -SO ₂ NHR ^N (R ^N is a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group) , represents a cyano group), an amide group, a carbonylimide group, a sulfonylimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O)NHSO ₂ R ^P (R ^P is an alkyl group or an aryl group).

In general formula (1),
Y represents a hydrogen atom or a hydrocarbon group.
A ₂ represents an aromatic ring group having an electron donating group. However, the electron donating group does not correspond to the acidic group.

[7]
The polymer according to [6], wherein the polymer includes a repeating unit represented by the following general formula (1-2) and a repeating unit represented by the following general formula (2-2).

[8]
(A) an onium salt compound;
(B1) Phenolic hydroxyl group, carboxyl group, -SO ₂ NHR ^N (R ^N is a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group), an amide group, a carbonylimide group, a sulfonylimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O)NHSO ₂ R ^P (R ^P is an alkyl group or an aryl group) a polymer having a repeating unit comprising at least one group selected from the group consisting of
An actinic ray-sensitive or radiation-sensitive resin composition, wherein the polymer has a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2).

In general formula (1),
Y represents a hydrogen atom or a hydrocarbon group.
A ² represents an aromatic ring group having an electron donating group. However, the electron-donating group does not correspond to the at least one group.

[9]
A resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [5] and [8].
[10]
forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [5] and [8];
a step of exposing the resist film;
A pattern forming method comprising the step of developing the exposed resist film using a developer.
[11]
A method for manufacturing an electronic device, comprising the pattern forming method according to [10].

According to the present invention, in forming ultra-fine patterns (for example, line and space patterns with line widths of 15 nm or less, hole patterns with hole diameters of 15 nm or less, etc.), it is possible to form patterns with excellent sensitivity and LWR performance. Actinic ray-sensitive or radiation-sensitive resin compositions can be provided.
Further, according to the present invention, it is possible to provide a resist film, a pattern forming method, and an electronic device manufacturing method using the actinic ray-sensitive or radiation-sensitive resin composition.
Moreover, according to the present invention, a polymer useful for the actinic ray-sensitive or radiation-sensitive resin can be provided.

The present invention will be explained in detail below.
Although the description of the constituent elements described below may be made based on typical embodiments of the present invention, the present invention is not limited to such embodiments.
Regarding the notation of groups (atomic groups) in this specification, unless it goes against the spirit of the present invention, the notation that does not indicate substituted or unsubstituted includes groups having a substituent as well as groups having no substituent. do. For example, the term "alkyl group" includes not only an alkyl group without a substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). Furthermore, the term "organic group" as used herein refers to a group containing at least one carbon atom.
Unless otherwise specified, the substituent is preferably a monovalent substituent.
In this specification, "active rays" or "radiation" include, for example, the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet (EUV), X-rays, and electron beams (EB: Electron Beam), etc. "Light" in this specification means actinic rays or radiation.
In this specification, "exposure" refers not only to exposure to the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays, X-rays, and EUV light, but also to electron beams and It also includes drawing using particle beams such as ion beams.
In the present specification, "~" is used to include the numerical values described before and after it as a lower limit value and an upper limit value.
The direction of bonding of the divalent groups described herein is not limited unless otherwise specified. For example, when Y in the compound represented by the formula "X-Y-Z" is -COO-, Y may be -CO-O- or -O-CO- Good too. Further, the above compound may be "X-CO-O-Z" or "X-O-CO-Z".

In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (also referred to as molecular weight distribution) (Mw/Mn) of the resin are measured using a GPC (Gel Permeation Chromatography) apparatus (HLC-8120GPC manufactured by Tosoh). ) GPC measurement (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: Tosoh TSK gel Multipore HXL-M, column temperature: 40°C, flow rate: 1.0 mL/min, detector: differential refractive index Defined as a polystyrene equivalent value determined by a Refractive Index Detector.

In this specification, acid dissociation constant (pKa) refers to pKa in an aqueous solution, and specifically, using the following software package 1, a value based on Hammett's substituent constant and a database of known literature values is calculated. , is a value obtained by calculation. All pKa values described herein are values calculated using this software package.

Software package 1: Advanced Chemistry Development (ACD/Labs) Software V8.14 for Solaris (1994-2007 ACD/Labs).

On the other hand, pKa can also be determined by molecular orbital calculation method. A specific method for this includes a method of calculating H 2 ⁺ dissociation free energy in an aqueous solution based on a thermodynamic cycle. The H ⁺ dissociation free energy can be calculated, for example, by DFT (density functional theory), but various other methods have been reported in the literature, and the method is not limited to this. . Note that there is a plurality of software that can perform DFT, and one example is Gaussian 16.

As mentioned above, pKa in this specification refers to a value obtained by calculating a value based on Hammett's substituent constant and a database of known literature values using software package 1. If calculation is not possible, a value obtained by Gaussian 16 based on DFT (density functional theory) is adopted.
In addition, pKa in this specification refers to "pKa in an aqueous solution" as described above, but if pKa in an aqueous solution cannot be calculated, "pKa in a dimethyl sulfoxide (DMSO) solution" is adopted. It shall be.

In this specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In this specification, the solid content is intended to be a component that forms a resist film, and does not include a solvent. Furthermore, if the component forms a resist film, it is considered to be a solid component even if the component is liquid.

[Actinic ray-sensitive or radiation-sensitive resin composition]
Actinic ray-sensitive or radiation-sensitive resin composition (hereinafter also referred to as "resist composition") of the present invention.
)teeth,
(A) an onium salt compound;
(B) a polymer having a repeating unit containing an acidic group having an acidic proton and whose main chain decomposes upon irradiation with actinic rays or radiation;
The above polymer has a repeating unit represented by the following general formula (1).

Due to the above structure, the resist composition of the present invention can form a pattern with excellent sensitivity and excellent LWR performance in ultrafine pattern formation. Although the reason for this is not clear in detail, the present inventors speculate as follows.
The polymer (B) contained in the resist composition of the present invention is a polymer whose main chain is decomposed by irradiation with actinic rays or radiation, and has a repeating unit represented by the above general formula (1). Since the aromatic ring group bonded to the main chain has an electron-donating group, the electron density in the aromatic ring becomes high, which has the effect of stabilizing intermediates in the main chain decomposition process, resulting in polymer (B) It is thought that main chain decomposition is promoted. As a result, the resist composition of the present invention has high sensitivity, and the resist film formed using the resist composition of the present invention has a high dissolution contrast between the unexposed area and the exposed area, resulting in excellent LWR performance. It is thought that it can be obtained.
Furthermore, the polymer (B) contained in the resist composition of the present invention has a repeating unit containing an acidic group having an acidic proton. Since this acidic group having an acidic proton is a group that can interact with the onium salt compound (A) in the resist composition, in the unexposed part of the resist film formed using the resist composition of the present invention, , the onium salt compound (A) and the polymer (B) interact, making it difficult to dissolve in the developer. On the other hand, when exposed to light, the main chain of the polymer (B) decomposes and the interaction between the onium salt compound (A) and the polymer (B) is canceled, making it easier to dissolve in the developer. In other words, it is thought that the dissolution contrast between the unexposed area and the exposed area of the resist film becomes higher due to the above-mentioned effect, so that better sensitivity and LWR performance can be obtained.
In the following, the fact that the sensitivity of the resist composition is better and/or the LWR performance of a pattern formed from the resist composition is better is also referred to as "the effect of the present invention is better."

Hereinafter, first, various components contained in the resist composition will be explained.

[Onium salt compound (A)]
The resist composition of the present invention contains an onium salt compound (A).
The onium salt compound (A) is more preferably a compound with an onium salt structure (photodegradable onium salt compound) that generates an acid upon irradiation with actinic rays or radiation.
When the resist composition contains an onium salt compound (A) such as a photodegradable onium salt compound, in the unexposed area, the polymer (B) is an acidic compound having an acidic proton that may be contained in the polymer (B). It tends to aggregate with the onium salt compound (A) through the group. On the other hand, when exposed to light, the above-mentioned agglomerated structure may be released due to dissociation between the onium salt compound (A) and an acidic group having an acidic proton and cleavage of the photodegradable onium salt compound. In other words, the effect of the present invention can be obtained because the above action increases the dissolution contrast between the unexposed area and the exposed area of the resist film.

The photodegradable onium salt compound will be explained below.
A photodegradable onium salt compound is a compound that has at least one salt structure site consisting of an anion site and a cation site, and that decomposes upon exposure to light to generate an acid (preferably an organic acid). preferable.
The above-mentioned salt structure moiety of the photodegradable onium salt compound is easily decomposed by exposure to light and is superior in organic acid production, and is composed of an organic cation moiety and an organic anion moiety with extremely low nucleophilicity. It is preferable that
The above-mentioned salt structure site may be a part of the photodegradable onium salt compound, or may be the entirety. In addition, the case where the above-mentioned salt structure part is a part of a photodegradable onium salt compound corresponds to a structure in which two or more salt structure parts are connected, for example, as in the photodegradable onium salt PG2 described below. do.
The number of salt structural moieties in the photodegradable onium salt is not particularly limited, but is preferably from 1 to 10, preferably from 1 to 6, and more preferably from 1 to 3.

Examples of organic acids generated from photodegradable onium salt compounds due to the action of exposure mentioned above include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphor sulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, etc.) , aromatic carboxylic acid, aralkylcarboxylic acid, etc.), carbonylsulfonylimidic acid, bis(alkylsulfonyl)imidic acid, and tris(alkylsulfonyl)methide acid.
Further, the organic acid generated from the photodegradable onium salt compound by the action of exposure may be a polyhydric acid having two or more acid groups. For example, when the photodegradable onium salt compound is the photodegradable onium salt compound PG2 described below, the organic acid generated by decomposition of the photodegradable onium salt compound due to exposure to light becomes a polyhydric acid having two or more acid groups. .

In the photodegradable onium salt compound, the cation moiety constituting the salt structure moiety is preferably an organic cation moiety, and in particular, an organic cation (cation (ZaI)) represented by the formula (ZaI) described below. Alternatively, an organic cation (cation (ZaII)) represented by formula (ZaII) is preferable.

(Photodegradable onium salt compound PG1)
An example of a preferred embodiment of ^the photodegradable onium salt compound is an onium salt compound represented by "M ⁺ ).
In the compound represented by "M ⁺ X ^- ", M ⁺ represents an organic cation and X ^- represents an organic anion.
The photodegradable onium salt compound PG1 will be explained below.

The organic cation represented by M ⁺ in the photodegradable onium salt compound PG1 is an organic cation represented by the formula (ZaI) (cation (ZaI)) or an organic cation (cation (ZaI)) represented by the formula (ZaII). ZaII)) is preferred.

In the above formula (ZaI),
R ²⁰¹ , R ²⁰² and R ²⁰³ each independently represent an organic group.
The organic groups as R ²⁰¹ , R ²⁰² and R ²⁰³ usually have 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. Furthermore, two of R ²⁰¹ to R ²⁰³ may be combined to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. Examples of the group formed by combining two of R ²⁰¹ to R ²⁰³ include an alkylene group (for example, a butylene group and a pentylene group), and -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -. Can be mentioned.

Preferred embodiments of the organic cation in formula (ZaI) include cation (ZaI-1), cation (ZaI-2), and organic cation (cation (ZaI-3b)) represented by formula (ZaI-3b), which will be described later. ), and an organic cation (cation (ZaI-4b)) represented by the formula (ZaI-4b).

First, the cation (ZaI-1) will be explained.
The cation (ZaI-1) is an arylsulfonium cation in which at least one of R ²⁰¹ to R ²⁰³ in the above formula (ZaI) is an aryl group.
In the arylsulfonium cation, all of R ²⁰¹ to R ²⁰³ may be an aryl group, or some of R ²⁰¹ to R ²⁰³ may be an aryl group, and the remainder may be an alkyl group or a cycloalkyl group.
Further, one of R ²⁰¹ to R ²⁰³ may be an aryl group, and the remaining two of R ²⁰¹ to R ²⁰³ may be bonded to form a ring structure, with an oxygen atom, a sulfur atom, It may contain an ester group, an amide group, or a carbonyl group. The group formed by combining two of R ²⁰¹ to R ²⁰³ includes, for example, one or more methylene groups substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and/or a carbonyl group. and alkylene groups (eg, butylene group, pentylene group, or -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -).
Examples of the arylsulfonium cation include triarylsulfonium cation, diarylalkylsulfonium cation, aryldialkylsulfonium cation, diarylcycloalkylsulfonium cation, and aryldicycloalkylsulfonium cation.

The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the heterocyclic structure include pyrrole residue, furan residue, thiophene residue, indole residue, benzofuran residue, and benzothiophene residue. When the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group or cycloalkyl group that the arylsulfonium cation has as necessary is a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a branched alkyl group having 3 to 15 carbon atoms. A cycloalkyl group is preferred, and for example, a methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, and cyclohexyl group are more preferred.

The substituents that the aryl group, alkyl group, and cycloalkyl group of R ²⁰¹ to R ²⁰³ may each independently include an alkyl group (for example, carbon number 1 to 15), a cycloalkyl group (for example, carbon number 3-15), aryl group (e.g. 6-14 carbon atoms), alkoxy group (e.g. 1-15 carbon atoms), cycloalkylalkoxy group (e.g. 1-15 carbon atoms), halogen atom (e.g. fluorine, iodine), hydroxyl group , a carboxyl group, an ester group, a sulfinyl group, a sulfonyl group, an alkylthio group, a phenylthio group, and the like.
The above substituent may further have a substituent if possible. For example, the above alkyl group may have a halogen atom as a substituent to become a halogenated alkyl group such as a trifluoromethyl group. preferable.

Next, the cation (ZaI-2) will be explained.
The cation (ZaI-2) is a cation in which R ²⁰¹ to R ²⁰³ in the formula (ZaI) each independently represent an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ²⁰¹ to R ²⁰³ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R ²⁰¹ to R ²⁰³ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, and a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxy A carbonylmethyl group is more preferred, and a linear or branched 2-oxoalkyl group is even more preferred.

The alkyl group and cycloalkyl group of R ²⁰¹ to R ²⁰³ include, for example, a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group). group, butyl group, and pentyl group), and cycloalkyl groups having 3 to 10 carbon atoms (eg, cyclopentyl group, cyclohexyl group, and norbornyl group).
R ²⁰¹ to R ²⁰³ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

Next, the cation (ZaI-3b) will be explained.
The cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).

In formula (ZaI-3b),
R _1c to R _5c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, and a hydroxyl group. , represents a nitro group, an alkylthio group, or an arylthio group.
R _6c and R _7c each independently represent a hydrogen atom, an alkyl group (such as a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group.
R _x and R _y each independently represent an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.

Any two or more of R _1c to R _5c , R _5c and R _6c , R _6c and R _7c , R _5c and R _x , and R _x and R _y may be bonded to each other to form a ring. Often, the rings may each independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
Examples of the above-mentioned ring include an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic heterocycle, and a polycyclic condensed ring formed by combining two or more of these rings. Examples of the ring include a 3- to 10-membered ring, preferably a 4- to 8-membered ring, and more preferably a 5- or 6-membered ring.

Examples of the group formed by combining any two or more of R _1c to R _5c , R _6c and R _7c , and R _x and R _y include alkylene groups such as a butylene group and a pentylene group. The methylene group in this alkylene group may be substituted with a hetero atom such as an oxygen atom.
The group formed by bonding R _5c and R _6c and R _5c and R _x is preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group.

R _1c to R _5c , R _6c , R _7c , R _x , R _y , and any two or more of R _1c to R 5c , R _5c and R _6c , R _6c and R _7c , _{R 5c} _and R _x , and the ring formed by bonding R _x and R _y to each other may have a substituent.

Next, the cation (ZaI-4b) will be explained.
The cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).

In formula (ZaI-4b),
l represents an integer from 0 to 2.
r represents an integer from 0 to 8.
_R13 is a group having a hydrogen atom, a halogen atom (for example, a fluorine atom, an iodine atom, etc.), a hydroxyl group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a cycloalkyl group (cycloalkyl It may be a group itself or a group partially containing a cycloalkyl group). These groups may have substituents.
R ₁₄ is a hydroxyl group, a halogen atom (for example, a fluorine atom, an iodine atom, etc.), an alkyl group,
A halogenated alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group having a cycloalkyl group (it may be a cycloalkyl group itself, or a cycloalkyl group may be a part of a cycloalkyl group) may be a group containing). These groups may have substituents. When a plurality of R _14s exist, each independently represents the above group such as a hydroxyl group.
R ₁₅ each independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. Two R _15s may be bonded to each other to form a ring. When two R _15s combine with each other to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom. In one embodiment, two R _15s are alkylene groups and are preferably bonded to each other to form a ring structure. The ring formed by bonding the alkyl group, cycloalkyl group, naphthyl group, and two R _15s to each other may have a substituent.

In formula (ZaI-4b), the alkyl groups of R ₁₃ , R ₁₄ and R ₁₅ are preferably linear or branched. The number of carbon atoms in the alkyl group is preferably 1 to 10. As the alkyl group, a methyl group, ethyl group, n-butyl group, or t-butyl group is more preferable.

Next, formula (ZaII) will be explained.
In formula (ZaII), R ²⁰⁴ and R ²⁰⁵ each independently represent an aryl group, an alkyl group, or a cycloalkyl group.
The aryl group for R ²⁰⁴ and R ²⁰⁵ is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group of R ²⁰⁴ and R ²⁰⁵ may be an aryl group having a heterocycle having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.
The alkyl group and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ include a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, butyl group, pentyl group), or a cycloalkyl group having 3 to 10 carbon atoms (eg, cyclopentyl group, cyclohexyl group, or norbornyl group).

The aryl group, alkyl group, and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ may each independently have a substituent. Examples of substituents that the aryl group, alkyl group, and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ may have include an alkyl group (for example, having 1 to 15 carbon atoms), a cycloalkyl group (for example, having 3 to 15 carbon atoms), 15), an aryl group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

The organic anion represented by X ^- in the photodegradable onium salt compound PG1 is preferably a non-nucleophilic anion (an anion with extremely low ability to cause a nucleophilic reaction).
Examples of non-nucleophilic anions include sulfonic acid anions (aliphatic sulfonic acid anions, aromatic sulfonic acid anions, camphor sulfonic acid anions, etc.), carboxylic acid anions (aliphatic carboxylic acid anions, aromatic carboxylic acid anions) , and aralkylcarboxylic acid anions), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

It is also preferable that the organic anion is, for example, an organic anion represented by the following formula (DA).

In formula (DA), A ₃₁ ^- represents an anionic group. R _a1 represents a hydrogen atom or a monovalent organic group. L _a1 represents a single bond or a divalent linking group.

A ₃₁ ^- represents an anionic group. The anionic group represented by A ₃₁ ^- is not particularly limited, but is preferably a group selected from the group consisting of groups represented by formulas (B-1) to (B-14), for example. , among others, formula (B-1), formula (B-2), formula (B-3), formula (B-4), formula (B-5), formula (B-6), formula (B- 10), formula (B-12), formula (B-13), or formula (B-14) are more preferred.

*-O ^-Formula (B-14)

In formulas (B-1) to (B-14), * represents the bonding position.
In formulas (B-1) to (B-5) and formula (B-12), R ^X1 each independently represents a monovalent organic group.
In formulas (B-7) and (B-11), R ^X2 each independently represents a hydrogen atom or a substituent other than a fluorine atom and a perfluoroalkyl group. Two R ^X2 's in formula (B-7) may be the same or different.
In formula (B-8), R ^XF1 represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, at least one of the two R ^XF1 represents a fluorine atom or a perfluoroalkyl group. Two R ^XF1 's in formula (B-8) may be the same or different.
In formula (B-9), R ^X3 represents a hydrogen atom, a halogen atom, or a monovalent organic group. n1 represents an integer from 0 to 4. When n1 represents an integer of 2 to 4, a plurality of R ^X3 may be the same or different.
In formula (B-10), R ^XF2 represents a fluorine atom or a perfluoroalkyl group.
The partner to which the bonding position represented by * in formula (B-14) is bonded is preferably a phenylene group which may have a substituent. Examples of the substituent that the phenylene group may have include a halogen atom.

In formulas (B-1) to (B-5) and formula (B-12), R ^X1 each independently represents a monovalent organic group.
R ^X1 is an alkyl group (which may be linear or branched, preferably having 1 to 15 carbon atoms), or a cycloalkyl group (which may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms). ), or an aryl group (which may be monocyclic or polycyclic. The number of carbon atoms is preferably 6 to 20). Further, the above group represented by R ^X1 may have a substituent.
In addition, in formula (B-5), it is also preferable that the atom directly bonded to N- in R ^X1 is neither the carbon atom in -CO- nor the sulfur atom in -SO ₂ -.

The cycloalkyl group in R ^X1 may be monocyclic or polycyclic.
Examples of the cycloalkyl group for R ^X1 include a norbornyl group and an adamantyl group.

The substituent that the cycloalkyl group in ^R One or more of the carbon atoms that are ring member atoms of the cycloalkyl group in R ^X1 may be replaced with a carbonyl carbon atom.

The number of carbon atoms in the alkyl group in R ^X1 is preferably 1 to 10, more preferably 1 to 5.
The substituent that the alkyl group in R ^X1 may have is not particularly limited, but is preferably a cycloalkyl group, a fluorine atom, or a cyano group.
Examples of the cycloalkyl group as the above-mentioned substituent include the cycloalkyl group described in the case where R ^X1 is a cycloalkyl group.
When the alkyl group in R ^X1 has a fluorine atom as the substituent, the alkyl group may be a perfluoroalkyl group.
Furthermore, in the alkyl group in R ^X1 , one or more -CH ₂ - may be substituted with a carbonyl group.

The aryl group for R ^X1 is preferably a benzene ring group.
The substituent that the aryl group in R ^X1 may have is not particularly limited, but is preferably an alkyl group, a fluorine atom, or a cyano group. Examples of the alkyl group as the above-mentioned substituent include the alkyl groups explained in the case where R ^X1 is an alkyl group.

In formulas (B-7) and (B-11), ^R ). Two R ^X2 's in formula (B-7) may be the same or different.

In formula (B-8), R ^XF1 represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, at least one of the plurality of R ^XF1 represents a fluorine atom or a perfluoroalkyl group. Two R ^XF1 's in formula (B-8) may be the same or different. The number of carbon atoms in the perfluoroalkyl group represented by R ^XF1 is preferably 1 to 15, more preferably 1 to 10, and even more preferably 1 to 6.

In formula (B-9), R ^X3 represents a hydrogen atom, a halogen atom, or a monovalent organic group. Examples of the halogen atom as R ^X3 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, of which a fluorine atom is preferred.
The monovalent organic group as R ^X3 is the same as the monovalent organic group described as R ^X1 .
n1 represents an integer from 0 to 4.
n1 is preferably an integer of 0 to 2, and preferably 0 or 1. When n1 represents an integer of 2 to 4, a plurality of R ^X3 may be the same or different.

In formula (B-10), R ^XF2 represents a fluorine atom or a perfluoroalkyl group.
The number of carbon atoms in the perfluoroalkyl group represented by R ^XF2 is preferably 1 to 15, more preferably 1 to 10, and even more preferably 1 to 6.

In formula (DA), the monovalent organic group R _a1 is not particularly limited, but generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R _a1 is preferably an alkyl group, a cycloalkyl group, or an aryl group.

The alkyl group may be linear or branched, and preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and even more preferably has 1 to 10 carbon atoms.
The cycloalkyl group may be monocyclic or polycyclic, preferably a cycloalkyl group having 3 to 20 carbon atoms, more preferably a cycloalkyl group having 3 to 15 carbon atoms, and still more preferably a cycloalkyl group having 3 to 10 carbon atoms. preferable.
The aryl group may be monocyclic or polycyclic, preferably having 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and even more preferably 6 to 10 carbon atoms.

The cycloalkyl group may contain a heteroatom as a ring member atom.
Heteroatoms include, but are not particularly limited to, nitrogen atoms, oxygen atoms, and the like.
Further, the cycloalkyl group may include a carbonyl bond (>C=O) as a ring member atom.
The alkyl group, cycloalkyl group, and aryl group described above may further have a substituent.
Furthermore, A ^31- and R _a1 may be bonded to each other to form a ring.

The divalent linking group as L _a1 is not particularly limited, but includes alkylene groups, cycloalkylene groups, aromatic groups, -O-, -CO-, -COO-, and groups formed by combining two or more of these. represent.
The alkylene group may be linear or branched and preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms.
The cycloalkylene group may be monocyclic or polycyclic, and preferably has 3 to 20 carbon atoms, more preferably 3 to 10 carbon atoms.
The aromatic group is a divalent aromatic group, preferably an aromatic group having 6 to 20 carbon atoms, and more preferably an aromatic group having 6 to 15 carbon atoms.
The aromatic ring constituting the aromatic group is not particularly limited, but examples include aromatic rings having 6 to 20 carbon atoms, and specific examples include benzene ring, naphthalene ring, anthracene ring, and thiophene ring. . The aromatic ring constituting the aromatic group is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.
The alkylene group, cycloalkylene group, and aromatic group may further have a substituent, and the substituent is preferably a halogen atom.
L _a1 preferably represents a single bond.

Examples of the photodegradable onium salt compound PG1 include paragraphs [0135] to [0171] of International Publication No. 2018/193954, paragraphs [0077] to [0116] of International Publication No. 2020/066824, and International Publication No. 2017/154345. It is also preferable to use the photoacid generators disclosed in paragraphs [0018] to [0075] and [0334] to [0335].

The molecular weight of the photodegradable onium salt compound PG1 is preferably 3000 or less, more preferably 2000 or less, and even more preferably 1000 or less.

(Photodegradable onium salt compound PG2)
In addition, as another example of a preferred embodiment of the photodegradable onium salt compound, the following compound (I) and compound (II) (hereinafter, "compound (I) and compound (II)") are referred to as "photodegradable onium salt compound PG2". ). The photodegradable onium salt compound PG2 is a compound that has two or more of the above-described salt structure sites and generates a polyvalent organic acid upon exposure to light.
The photodegradable onium salt compound PG2 will be explained below.

<<Compound (I)>>
Compound (I) is a compound having one or more of the following structural moieties X and one or more of the following structural moieties Y, and the following first acidic acid derived from the following structural moiety This is a compound that generates an acid containing the following second acidic site derived from the structural site Y below.
^structural _site _{_} ^_ _{_} ₂ ^- and a cationic site M ₂ ⁺ , and forms a second acidic site represented by HA ₂ upon irradiation with actinic rays or radiation. However, compound (I) satisfies the following condition I.

Condition I: A compound PI obtained by replacing the cation moiety M ₁ ⁺ in the structural moiety X and the cation moiety M ₂ ⁺ in the structural moiety Y with H ⁺ in the compound (I) is The acid dissociation constant _{a1 derived from the acidic site represented by HA 1} _is obtained by replacing the cationic site M 1 ⁺ with H ⁺ , and the acid dissociation constant a1 derived from the acidic site represented by HA 1 is obtained by replacing the cationic site M ₂ ⁺ in the structural site Y with H ⁺ It has an acid dissociation constant a2 derived from the acidic site represented by HA ₂ , and the acid dissociation constant a2 is larger than the acid dissociation constant a1.
The above-mentioned compound PI corresponds to an acid generated when compound (I) is irradiated with actinic rays or radiation.

When compound (I) has two or more structural sites X, the structural sites X may be the same or different. Furthermore, the two or more A ₁ ⁻ and the two or more M ₁ ⁺ may be the same or different.
Further, in compound (I), the above A ₁ ^- and the above A ₂ ^- , and the above M ₁ ⁺ and the above M ₂ ⁺ may be the same or different, but the above A ₁ ^- and the above Preferably, each A ₂ ^- is different.

The anionic moiety A ₁ ^- and the anionic moiety A ₂ ^- are structural moieties containing negatively charged atoms or atomic groups, for example, the formulas (AA-1) to (AA-3) and the formula (BB Examples include structural sites selected from the group consisting of -1) to (BB-6). Note that in the following formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6), * represents the bonding position. Moreover, R ^A represents a monovalent organic group. Examples of the monovalent organic group represented by R ^A include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

Further, the cationic site M ₁ ⁺ and the cationic site M ₂ ⁺ are structural sites containing positively charged atoms or atomic groups, such as monovalent organic cations. The organic cation is not particularly limited, but is preferably an organic cation (cation (ZaI)) represented by the above-mentioned formula (ZaI) or an organic cation (cation (ZaII)) represented by the formula (ZaII).

<<Compound (II)>>
Compound (II) is a compound having two or more of the above structural moieties It is a compound that generates an acid containing two or more sites and the above structural site Z.
Structural site Z: nonionic site capable of neutralizing acids

The above compound (II) is a compound PII (acid) having an acidic site represented by HA ₁ obtained by replacing the above cation site M ₁ ⁺ in the above structural site X with H ⁺ by irradiation with actinic rays or radiation. It can occur. That is, compound PII represents a compound having the acidic site represented by HA ₁ above and the structural site Z, which is a nonionic site capable of neutralizing acid.
In addition, the definition of the structural moiety X and the definitions of A ₁ ^- and M ₁ ⁺ in compound (II) are the same as the definition of the structural moiety X and A ₁ ^- and M ₁ ⁺ in compound (I) described above. It has the same meaning as the definition, and the preferred embodiments are also the same.
Furthermore, the two or more structural sites X may be the same or different. Furthermore, the two or more A ₁ ⁻ and the two or more M ₁ ⁺ may be the same or different.

The nonionic site that can neutralize the acid in the structural site Z is not particularly limited, and is preferably a site that contains a group that can electrostatically interact with protons or a functional group that has electrons. .
As a group capable of electrostatic interaction with protons or a functional group having electrons, a functional group having a macrocyclic structure such as a cyclic polyether, or a nitrogen atom having a lone pair of electrons that does not contribute to π conjugation is used. Examples include functional groups having such a functional group. A nitrogen atom having a lone pair of electrons that does not contribute to π conjugation is, for example, a nitrogen atom having a partial structure shown in the following formula.

Examples of partial structures of functional groups having groups or electrons that can electrostatically interact with protons include crown ether structures, aza crown ether structures, primary to tertiary amine structures, pyridine structures, imidazole structures, and pyrazine structures. Among them, primary to tertiary amine structures are preferred.

The molecular weight of the photodegradable onium salt compound PG2 is preferably 100 to 10,000, more preferably 100 to 2,500, even more preferably 100 to 1,500.

As the photodegradable onium salt compound PG2, compounds exemplified in paragraphs [0023] to [0095] of International Publication No. 2020/158313 can be cited.

Hereinafter, examples of moieties other than cations that the photodegradable onium salt compound PG2 may have will be shown.

In the resist composition of the present invention, the content of the onium salt compound (A) is preferably 0.1 to 20% by mass based on the total solid content of the resist composition. If it is 0.1% by mass or more, the dissolution contrast between the unexposed area and the exposed area, which is caused by the presence or absence of interaction with the acidic group having an acidic proton in the polymer (B), increases, and the effects of the present invention can be obtained. Cheap. The lower limit of the content is more preferably 0.5% by mass or more, further preferably 1.0% by mass or more, and particularly preferably 2.0% by mass or more. Moreover, if the content is 20% by mass or less, the unexposed area will have appropriate solubility, the sensitivity will be better, and the effects of the present invention will be more likely to be obtained. The upper limit of the content is more preferably 10.0% by mass or less, and even more preferably 5.0% by mass or less.
The onium salt compound (A) may be used alone or in combination of two or more. When two or more types are used, it is preferable that the total content is within the above-mentioned preferred content range.

[Polymer (B)]
The resist composition of the present invention includes a polymer (hereinafter also referred to as polymer (B)) that has a repeating unit containing an acidic group having an acidic proton and whose main chain is decomposed by irradiation with actinic rays or radiation. The polymer (B) has a repeating unit represented by the following general formula (1).

The polymer (B) is a so-called main chain-cleaved polymer whose main chain is decomposed (the main chain is cut) by irradiation with actinic rays or radiation. The polymer (B) is preferably a polymer whose main chain decomposes when irradiated with X-rays, electron beams or extreme ultraviolet rays, and preferably whose main chain decomposes when irradiated with electron beams or extreme ultraviolet rays. More preferred.

The polymer (B) includes a repeating unit represented by the following general formula (1) and a repeating unit for the polymer (B) to function as a main chain cleavage type polymer (preferably, a repeating unit represented by the general formula (2) described below). It is preferable that it is a copolymer containing a repeating unit represented by The polymer (B) may be a random copolymer, a block copolymer, or an alternating copolymer, and more preferably an alternating copolymer.

<Repeating unit containing an acidic group having an acidic proton>
The polymer (B) has a repeating unit containing an acidic group having an acidic proton. The acidic group having an acidic proton acts as a group that interacts with the above-mentioned onium salt compound (A).
The acidic group having an acidic proton is a phenolic hydroxyl group, a carboxyl group, -SO ₂ NHR ^N (R ^N is a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, arylsulfonyl group, cyano group), amide group, carbonylimide group, sulfonylimide group, thiol group substituted on a ring member atom of an aromatic ring, and -C(=O)NHSO ₂ R ^P (R ^P is represents at least one group selected from the group consisting of (representing an alkyl group or an aryl group).
Note that the above-mentioned phenolic hydroxyl group refers to a hydroxyl group substituted on a ring member atom of an aromatic ring.

The alkyl group for R ^N is preferably an alkyl group exemplified as the organic group W listed below, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and a methyl group, t -butyl group is more preferred, and methyl group is particularly preferred.
The alkyl group in the alkylcarbonyl group as R ^N is preferably an alkyl group exemplified as the organic group W below, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms. , methyl group, and t-butyl group are more preferred, and methyl group is particularly preferred.
Examples of the aryl group for R ^N include a phenyl group, a naphthyl group, an anthryl group, and the like, with a phenyl group being particularly preferred.
Examples of the aryl group in the arylcarbonyl group as R ^N include a phenyl group, a naphthyl group, an anthryl group, and a phenyl group is particularly preferred.
Examples of the alkoxycarbonyl group as R ^N include methyl ester and ethyl ester, with methyl ester being particularly preferred.
The alkyl group in the alkylsulfonyl group as R ^N is preferably an alkyl group exemplified below as an organic group W, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms. , methyl group, and t-butyl group are more preferred, and methyl group is particularly preferred.
Examples of the aryl group in the arylsulfonyl group as R ^N include a phenyl group, a naphthyl group, an anthryl group, and the like, with a phenyl group being particularly preferred.

Further, the sulfonylimide group is preferably a group represented by the following general formula (K1) or (K2).

In general formulas (K1) and (K2), * represents a substitution position, respectively.
In general formula (K2), R ^K represents an alkyl group or an aryl group.

The alkyl group as R ^K is preferably an alkyl group exemplified below as an organic group W, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and a methyl group, t -Butyl group is more preferred, and methyl group is particularly preferred.
Examples of the aryl group as R ^K include a phenyl group, a naphthyl group, an anthryl group, and the like, with a phenyl group being particularly preferred.
R ^K may further have a substituent. As the substituent, a halogen atom is preferable, and a fluorine atom is more preferable.

Further, the carbonylimide group is preferably a group represented by the following general formula (M1) or (M2).

In general formulas (M1) and (M2), * represents a substitution position, respectively.
In general formula (M2), R ^M represents an alkyl group or an aryl group.

The alkyl group as R ^M is preferably an alkyl group exemplified below as an organic group W, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and a methyl group, t -Butyl group is more preferred, and methyl group is particularly preferred.
Examples of the aryl group as R ^M include a phenyl group, a naphthyl group, an anthryl group, and the like, with a phenyl group being particularly preferred.
R ^M may further have a substituent. As the substituent, a halogen atom is preferable, and a fluorine atom is more preferable.

The aromatic ring to which the thiol group is bonded is not particularly limited, and may be an aromatic hydrocarbon ring or an aromatic heterocycle. Further, the aromatic ring may be monocyclic or polycyclic. Specifically, the groups exemplified as the aromatic ring in the aromatic ring group of A ² in the general formula (1) described below can be mentioned.
The same applies to the aromatic ring to which the hydroxyl group in the phenolic hydroxyl group is bonded.

The alkyl group represented by R ^P is preferably an alkyl group exemplified below as an organic group W, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and a methyl group or More preferred is t-butyl group.
The aryl group represented by R ^P is preferably an aryl group exemplified below as an organic group W, more preferably an aryl group having 6 to 10 carbon atoms, and even more preferably a phenyl group.

Acidic groups having acidic protons include phenolic hydroxyl groups, carboxyl groups, -SO ₂ NHR ^N (R ^N represents a hydrogen atom, an alkylcarbonyl group, or an arylcarbonyl group), an alkylsulfonyl group, an arylsulfonyl group, and an aromatic group. It is preferably at least one group selected from thiol groups substituted on ring member atoms of a ring, and more preferably at least one group selected from phenolic hydroxyl groups and carboxyl groups.

The repeating unit containing an acidic group having an acidic proton may be a repeating unit represented by general formula (1) described below, or may be a repeating unit represented by general formula (2), and may be a repeating unit represented by general formula (2). Other repeating units different from (1) and (2) may be used, but at least one of the repeating units represented by general formula (1) and the repeating unit represented by general formula (2) may be used. A repeating unit represented by general formula (1) is more preferable. The specific structure of the repeating unit will be described later.

In the polymer (B), the content of repeating units containing acidic groups having acidic protons is preferably 10 mol% or more, more preferably 20 mol% or more, based on all repeating units. , more preferably 40 mol% or more. In addition, the upper limit thereof is, for example, preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 80 mol% or less, and 60 mol% or less, based on all repeating units. It is particularly preferable that
In addition, in the polymer (B), one type of repeating unit containing an acidic group having an acidic proton may be contained alone, or two or more types may be contained. When two or more types are included, the total content is preferably within the above-mentioned preferred content range.

In general formula (1), Y represents a hydrogen atom or a hydrocarbon group.
Examples of the hydrocarbon group represented by Y include linear or branched alkyl groups, cycloalkyl groups, and aryl groups.
The linear or branched alkyl group represented by Y is preferably an alkyl group exemplified as the organic group W listed below, more preferably an alkyl group having 1 to 6 carbon atoms, and a methyl group. Or ethyl group is more preferable.
The cycloalkyl group represented by Y is preferably a cycloalkyl group exemplified as the organic group W listed below, and more preferably a cyclopentyl group or a cyclohexyl group.
The aryl group represented by Y is preferably an aryl group exemplified as the organic group W listed below, and more preferably a phenyl group or a naphthyl group.

Y is preferably a methyl group or an ethyl group, more preferably a methyl group.

In general formula (1), A ² represents an aromatic ring group having an electron donating group. However, the electron donating group does not correspond to the acidic group.
Examples of the aromatic ring in the aromatic ring group that A ² has include an aromatic hydrocarbon ring and an aromatic heterocycle. The aromatic ring may be monocyclic or polycyclic.
The aromatic hydrocarbon ring is not particularly limited, but includes, for example, an aromatic hydrocarbon ring having 6 to 20 carbon atoms. Specific examples include a benzene ring, a naphthalene ring, an anthracene ring, an acenaphthylene ring, etc., with a benzene ring or a naphthalene ring being preferred, and a benzene ring being more preferred.
The aromatic heterocycle is not particularly limited, but for example, an aromatic heterocycle having 3 to 20 carbon atoms (heteroatoms contained in the ring include, for example, oxygen atom, sulfur atom, nitrogen atom, etc.) Can be mentioned. Specific examples include a thiophene ring, a furan ring, a pyridine ring, an imidazole ring, a benzimidazole ring, a benzothiazole ring, etc., with a thiophene ring, a furan ring, a benzimidazole ring, and a benzothiazole ring being preferred; A thiazole ring is more preferred.

The aromatic ring in the aromatic ring group that A ² has is preferably an aromatic hydrocarbon ring, and more preferably a benzene ring.

As the electron-donating group possessed by the above-mentioned aromatic ring group, an electron-donating group having a Hammett substituent constant σp value of less than 0 is preferably mentioned.

Here, Hammett's substituent constant σ value is a numerical expression of the effect of a substituent on the acid dissociation equilibrium constant of substituted benzoic acid, and is a parameter indicating the strength of the electron-withdrawing and electron-donating properties of the substituent. be. The Hammett substituent constant σp value (hereinafter also simply referred to as "σp value") in this specification means the substituent constant σ when the substituent is located at the para position of benzoic acid.
As the σp value of each group in this specification, the value described in the document "Hansch et al., Chemical Reviews, 1991, Vol. 91, No. 2, 165-195" is adopted. For groups for which the σp value is not shown in the above literature, the pKa of benzoic acid and the para position are calculated using the software "ACD/ChemSketch (ACD/Labs 8.00 Release Product Version: 8.08)". The σp value can be calculated based on the difference from the pKa of the benzoic acid derivative having a substituent.

The σp value of the electron-donating group is preferably -0.05 or less, more preferably -0.1 or less. The lower limit of the σp value of the electron-donating group is not particularly limited, but is preferably −0.9 or more.

Examples of the electron-donating group having a Hammett's substituent constant σp value of less than 0 include an alkyl group, an alkoxy group, an alkylthio group, a dialkylamino group, and a monoalkylamino group.
The alkyl group as the electron-donating group is preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and preferably a methyl group (σp=-0.17).
As the alkyl group moiety in the alkoxy group as an electron donating group, the above-mentioned alkyl group is preferable. The alkoxy group is preferably a methoxy group (σp=-0.27).
The alkyl group moiety in the alkylthio group as an electron-donating group is preferably the above alkyl group. The alkylthio group is preferably an ethylthio group (σp=-0.1).
As the alkyl group moiety in the dialkylamino group as an electron-donating group, the above-mentioned alkyl groups are preferable. The two alkyl groups in the dialkylamino group may be the same or different. The dialkylamino group is preferably a dimethylamino group (σp=-0.83).

The electron-donating group is preferably at least one group selected from an alkyl group, an alkoxy group, an alkylthio group, a dialkylamino group, and a monoalkylamino group; More preferably, it is at least one group selected from amino groups, and even more preferably at least one group selected from dialkylamino groups and monoalkylamino groups.

The number of electron-donating groups that the aromatic ring group has is not particularly limited, but is preferably 2 to 4, more preferably 2 or 3.

The aromatic ring group may have a substituent other than the electron-donating group. Among these, it is preferable to further include an acidic group having the above-mentioned acidic proton. In this case, the repeating unit represented by general formula (1) corresponds to the above-mentioned repeating unit containing an acidic group having an acidic proton.
The aromatic ring group may be bonded directly to the electron donating group or may be bonded to the electron donating group via a divalent linking group. Examples of the divalent linking group include a divalent linking group as L ² in general formula (1-2) described below.

The repeating unit represented by the above general formula (1) is preferably a repeating unit represented by the following general formula (1-2).

In general formula (1-2),
Y represents a hydrogen atom or a hydrocarbon group.
R ² represents an acidic group having an acidic proton. When a plurality of R ^2s exist, the plurality of R ^2s may be the same or different.
R ³ represents an electron donating group. When a plurality of R ^3s exist, the plurality of R ^3s may be the same or different. However, the electron donating group does not correspond to the acidic group.
L ² represents a single bond or a divalent linking group.
m represents an integer from 1 to 4.
n represents an integer from 1 to 4. However, 1≦m+n≦5 is satisfied.

Y in general formula (1-2) has the same meaning as Y in general formula (1), and preferred examples are also the same.
Examples of the acidic group having an acidic proton represented by R ² in the general formula (1-2) include the above-mentioned acidic group having an acidic proton, and preferred examples are also the same.
Examples of the electron-donating group represented by R ³ in the general formula (1-2) include the electron-donating group having the above-mentioned Hammett's substituent constant σp value of less than 0, and preferred examples are also the same.

The divalent linking group for L ² is not particularly limited, but includes, for example, an alkylene group, -O-, -C(=O)-, -S-, -SO ₂ -, or a combination of two or more of these. The following groups can be mentioned.
The alkylene group may be linear or branched, and includes alkylene groups having 1 to 6 carbon atoms.

In general formula (1-2), m is preferably an integer of 2 to 4, more preferably 2 or 3.
In general formula (1-2), n is preferably 1 or 2.

Hereinafter, specific examples of monomers constituting the repeating unit represented by general formula (1) will be given, but the present invention is not limited thereto.

In the polymer (B), the content of repeating units represented by general formula (1) is preferably 10 mol% or more, more preferably 20 mol% or more, based on all repeating units. The content is preferably 40 mol% or more, and more preferably 40 mol% or more. In addition, the upper limit thereof is, for example, preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 80 mol% or less, and 60 mol% or less, based on all repeating units. It is particularly preferable that
In addition, in the polymer (B), one type of repeating unit represented by general formula (1) may be contained alone, or two or more types may be contained. When two or more types are included, the total content is preferably within the above-mentioned preferred content range.

<Repeating unit represented by general formula (2)>
The polymer (B) preferably has a repeating unit represented by the following general formula (2) as a repeating unit for the polymer (B) to function as a main chain cleavage type polymer.

In general formula (2), X represents a halogen atom.
Examples of the halogen atom represented by X include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogen atom represented by X is preferably a chlorine atom, a bromine atom, or an iodine atom, and more preferably a chlorine atom, since the effects of the present invention are more excellent.

The organic groups represented by R ¹ , R ⁰ , and A ¹ are not particularly limited, and include, for example, groups exemplified as the organic group W below.
(Organic group W)
The organic group W is, for example, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a cycloalkynyl group, an aryl group, a heteroaryl group, an aralkyl group, a cyano group, an alkoxy group, an aryloxy group, a heterocycle. Oxy group, acyl group (alkylcarbonyl group or arylcarbonyl group), acyloxy group (alkylcarbonyloxy group or arylcarbonyloxy group), carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, alkylthio group, arylthio group, Heterocyclic thio group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, aryloxycarbonyl group, alkoxycarbonyl group, aryl or heterocyclic azo group, sulfonamide group, imide group, acylamino group, carbamoyl group, lactone group, etc. can be mentioned.
Moreover, each of the above-mentioned groups may further have a substituent, if possible. For example, an alkyl group which may have a substituent is also included as one form of the organic group W. The above substituents are not particularly limited, but include, for example, one or more of the groups shown as the organic group W above, a halogen atom, a nitro group, a primary to tertiary amino group, a phosphino group, a phosphinyl group, Examples include a phosphinyloxy group, a phosphinylamino group, a phosphono group, a silyl group, a hydroxy group, a carboxy group, a sulfonic acid group, and a phosphoric acid group (hereinafter, these are referred to as "substituent T").
Further, the number of carbon atoms in the organic group W is, for example, 1 to 20.
Further, the number of atoms other than hydrogen atoms that the organic group W has is, for example, 1 to 30.

Further, the number of carbon atoms in the alkyl group exemplified in the organic group W is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6.
The alkyl group may be either linear or branched.
Examples of the alkyl group include linear or branched alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, and n-hexyl group. Can be mentioned.
In the alkyl group which may have a substituent, the substituent which the alkyl group may have is not particularly limited, and includes, for example, the groups exemplified by the above-mentioned substituent T.

The alkyl group moiety in the alkoxy group (including the alkoxy group moiety in a substituent containing an alkoxy group (e.g., alkoxycarbonyloxy group)), the alkyl group moiety in an aralkyl group, and the alkyl group in an alkylcarbonyl group exemplified in the organic group W As the alkyl group moiety in the alkylcarbonyloxy group, the alkyl group moiety in the alkylthio group, the alkyl group moiety in the alkylsulfinyl group, and the alkyl group moiety in the alkylsulfonyl group, the above alkyl groups are preferable. Also, an alkoxy group that may have a substituent, an aralkyl group that may have a substituent, an alkylcarbonyloxy group that may have a substituent, an alkylthio group that may have a substituent, a substituent In the alkylsulfinyl group which may have a substituent, and the alkylsulfonyl group which may have a substituent, an alkoxy group, an aralkyl group, an alkylcarbonyloxy group, an alkylthio group, an alkylsulfinyl group, and an alkylsulfonyl group have Examples of the substituent which may be substituted include the same substituents as those for the alkyl group which may have a substituent.

Examples of the cycloalkyl group for the organic group W include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, polycyclic cycloalkyl groups such as norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. Examples include alkyl groups. The number of carbon atoms in the cycloalkyl group is preferably 5 to 20, more preferably 5 to 15. In the cycloalkyl group which may have a substituent, examples of the substituent which the cycloalkyl group may have are the same as those for the alkyl group which may have a substituent.

The alkenyl group exemplified in the organic group W may be either linear or branched. The alkenyl group preferably has 2 to 20 carbon atoms. In the alkenyl group which may have a substituent, examples of the substituent which the alkenyl group may have are the same as those for the alkyl group which may have a substituent.
The cycloalkenyl group exemplified in the organic group W preferably has 5 to 20 carbon atoms. In the cycloalkenyl group which may have a substituent, examples of the substituent which the cycloalkenyl group may have are the same as those for the alkyl group which may have a substituent.
The alkynyl group exemplified as the organic group W may be linear, branched, or cyclic. The number of carbon atoms in the alkynyl group is preferably 2 to 20. In the alkynyl group which may have a substituent, examples of the substituent which the alkynyl group may have are the same as those for the alkyl group which may have a substituent.
The cycloalkynyl group exemplified as the organic group W preferably has 5 to 20 carbon atoms. In the cycloalkynyl group which may have a substituent, examples of the substituent which the cycloalkynyl group may have are the same as those for the alkyl group which may have a substituent.

The aryl group exemplified in the organic group W may be either monocyclic or polycyclic (eg, 2-6 rings, etc.) unless otherwise specified.
The number of ring member atoms in the aryl group is preferably 6 to 15, more preferably 6 to 10.
The aryl group is preferably a phenyl group, a naphthyl group, or an anthryl group, and more preferably a phenyl group.
In the aryl group which may have a substituent, examples of the substituent which the aryl group may have are the same as those for the alkyl group which may have a substituent.
Furthermore, among the groups exemplified in the organic group W, the same examples as the aryl group exemplified in the above organic group W are given for the aryl group moiety in a substituent containing an aryl group (for example, an aryloxy group). It will be done.

The heteroaryl group exemplified in the organic group W may be either monocyclic or polycyclic (eg, 2-6 rings, etc.) unless otherwise specified.
The number of heteroatoms that the heteroaryl group has as ring member atoms is, for example, 1 to 10. Examples of the heteroatoms include nitrogen atom, sulfur atom, oxygen atom, selenium atom, tellurium atom, phosphorus atom, silicon atom, and boron atom.
The number of ring member atoms in the above heteroaryl group is preferably 5 to 15.
In the heteroaryl group which may have a substituent, examples of the substituent which the heteroaryl group may have are the same as those for the alkyl group which may have a substituent.

The heterocycle exemplified in the organic group W is intended to be a ring containing a hetero atom as a ring member atom, and unless otherwise specified, it may be either an aromatic heterocycle or an aliphatic heterocycle, and may include a monocyclic ring and a polycyclic ring. It may be any ring (for example, 2 to 6 rings, etc.).
The number of heteroatoms that the heterocycle has as ring member atoms is, for example, 1 to 10. Examples of the heteroatoms include nitrogen atom, sulfur atom, oxygen atom, selenium atom, tellurium atom, phosphorus atom, silicon atom, and boron atom.
The number of ring member atoms in the heterocycle is preferably 5 to 15.
In the heterocycle which may have a substituent, examples of the substituent which the heterocycle may have are similar to the substituents in the alkyl group which may have a substituent.

The lactone group exemplified in the organic group W is preferably a 5- to 7-membered lactone group, and another ring structure is fused to the 5- to 7-membered lactone ring to form a bicyclo structure or a spiro structure. It is more preferable that
In the lactone group that may have a substituent, examples of the substituent that the lactone group may have include the same as the substituents for the alkyl group that may have a substituent.

Among these, a hydrogen atom is preferable as R ⁰ .
Among these, R ¹ is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

In addition, A ¹ preferably represents an organic group having a halogen atom (preferably one or more selected from the group consisting of a chlorine atom, a bromine atom, and an iodine atom), and represents an organic group having an iodine atom. Preferably it represents a group. Note that when A ¹ represents an organic group having a halogen atom, the organic group may further have a substituent other than the halogen atom.
In addition, as A ¹ , a group that forms an acidic group having an acidic proton as described above together with -C(=O)-L ¹ - in general formula (2) can be mentioned as a preferable embodiment. Specifically, along with -C(=O)-L ¹ -, a carboxy group, the above-mentioned carbonylimide group represented by (M2), and the above-mentioned -C(=O)NHSO ₂ R ^P (R ^P is, (representing an alkyl group or an aryl group). In this case, the repeating unit represented by general formula (2) corresponds to the above-mentioned repeating unit containing an acidic group having an acidic proton.

R ⁰ may be linked with A ¹ or R ¹ to form a ring.
The ring formed by connecting R ⁰ with A ¹ or R ¹ is not particularly limited, and may be either a monocyclic ring or a polycyclic ring. The above-mentioned ring may contain heteroatoms such as oxygen atom, nitrogen atom, and sulfur atom, and/or carbonyl carbon as ring member atoms.
Among these, the ring is preferably a 5- or 6-membered alicyclic ring.

The repeating unit represented by the above general formula (2) is preferably a repeating unit represented by the following general formula (2-2).

X, A ¹ and R ⁰ in general formula (2-2) have the same meanings as X, A ¹ and R ⁰ in general formula (2) above, respectively, and preferred examples are also the same.

Hereinafter, specific examples of monomers constituting the repeating unit represented by general formula (2) will be given, but the monomers are not limited thereto.

In the polymer (B), the content of repeating units represented by general formula (2) is preferably 10 mol% or more, more preferably 20 mol% or more, based on all repeating units. The content is preferably 40 mol% or more, and more preferably 40 mol% or more. In addition, the upper limit thereof is preferably 90 mol% or less, more preferably 80 mol% or less, still more preferably 70 mol% or less, and 60 mol% or less, based on all repeating units. The following is particularly preferred.
In addition, in the polymer (B), one type of repeating unit represented by general formula (2) may be contained alone, or two or more types may be contained. When two or more types are included, the total content is preferably within the above-mentioned preferred content range.

<Other repeating units>
The polymer (B) may contain repeating units other than the above-mentioned repeating units as long as the effects of the present invention are not impaired.
Specifically, for example, it may contain a repeating unit represented by the following general formula (3). Note that among the repeating units represented by general formula (3), those corresponding to the repeating units represented by general formula (1) above are treated as repeating units represented by general formula (1).

In general formula (3),
Y ³ represents a hydrogen atom or a hydrocarbon group.
Ar represents an aryl group.

Examples of the hydrocarbon group represented by Y ³ in the general formula (3) include the hydrocarbon group represented by Y in the above-mentioned general formula (1).
^Y3 is preferably a methyl group or an ethyl group, more preferably a methyl group.

In general formula (3), Ar represents an aryl group which may have a substituent.
The aryl group which may have a substituent is preferably an aryl group exemplified as the organic group W, and more preferably a phenyl group which may have a substituent. Examples of the substituent that the aryl group may have include the same substituents as the alkyl group that may have a substituent described above as the organic group W.
It is preferable that Ar represents an aryl group having a substituent, and the substituent contains a halogen atom. In other words, Ar is preferably an aryl group having a substituent containing a halogen atom.
When the aryl group has a halogen atom as a substituent, the number of halogen atoms is not particularly limited, but is preferably 1 to 5, more preferably 1 to 3.

Moreover, Ar may be an aryl group having an acidic group having the above-mentioned acidic proton as a substituent.
When the aryl group has an acidic group having an acidic proton as a substituent, the number of acidic groups having an acidic proton is not particularly limited, but is preferably 1 to 3, for example.
In this case, the repeating unit represented by general formula (3) corresponds to the above-mentioned repeating unit containing an acidic group having an acidic proton.

Hereinafter, specific examples of monomers constituting the repeating unit represented by general formula (3) will be given, but the monomers are not limited thereto.

In the case where the polymer (B) contains other repeating units, the content thereof is preferably 30 mol% or less, and 15 mol% or less based on all the repeating units. is more preferable.

The polymer (B) preferably contains a repeating unit represented by the above general formula (2) in addition to the repeating unit represented by the above general formula (1), and preferably contains a repeating unit represented by the above general formula (1-2). It is more preferable to include a repeating unit represented by the above general formula (2-2).

The weight average molecular weight of the polymer (B) is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 20,000 or more.
Moreover, the weight average molecular weight of the polymer (B) is preferably 200,000 or less, more preferably 150,000 or less, even more preferably 100,000 or less, and particularly preferably 85,000 or less.
The above weight average molecular weight value is a value determined as a polystyrene equivalent value by GPC method.
The degree of dispersion (molecular weight distribution) of the polymer (B) is usually 1.0 to 3.0, preferably 1.0 to 2.0, more preferably 1.0 to 1.8, and 1.0 ~1.6 is more preferred. When the degree of dispersion is within the above range, the resolution and resist shape tend to be better.

The polymer (B) can be synthesized according to a conventional method (for example, by radical polymerization). Details of synthesis examples are shown in Examples.

In the resist composition of the present invention, the content of the polymer (B) is preferably 50.0% by mass or more, more preferably 60.0% by mass or more, and 70.0% by mass or more based on the total solid content of the composition. More preferably, the amount is % by mass or more. Further, the upper limit is 100% by mass or less, preferably 99.9% by mass or less.
Further, the polymer (B) may be used alone or in combination. When two or more types are used, it is preferable that the total content is within the above-mentioned preferred content range.

〔solvent〕
The resist composition of the present invention preferably contains a solvent.
The solvent consists of (M1) propylene glycol monoalkyl ether carboxylate, and (M2) propylene glycol monoalkyl ether, lactic acid ester, acetate ester, alkoxypropionic acid ester, chain ketone, cyclic ketone, lactone, and alkylene carbonate. Preferably, at least one selected from the group . Note that this solvent may further contain components other than components (M1) and (M2).

When such a solvent and polymer (B) are used in combination, the coatability of the resist composition is improved and a pattern with a small number of development defects is easily formed. The reason for this is that these solvents have an excellent balance between the solubility, boiling point, and viscosity of the polymer (B), so they can reduce unevenness in the thickness of the resist film, which is a composition film of the resist composition, and precipitates during spin coating. This is presumed to be due to the ability to suppress the occurrence of.

Component (M1) is preferably at least one selected from the group consisting of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether propionate, and propylene glycol monoethyl ether acetate; Glycol monomethyl ether acetate (PGMEA) is more preferred.

As component (M2), the following are preferable.
As the propylene glycol monoalkyl ether, propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether (PGEE) are preferable.
As the lactic acid ester, ethyl lactate, butyl lactate, or propyl lactate is preferable.
As the acetic acid ester, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, or 3-methoxybutyl acetate is preferred.
Butyl butyrate is also preferred.
As the alkoxypropionate ester, methyl 3-methoxypropionate (MMP) or ethyl 3-ethoxypropionate (EEP) is preferable.
Examples of chain ketones include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, phenylacetone, methyl ethyl ketone, and methyl isobutyl. Ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetyl carbinol, acetophenone, methylnaphthyl ketone, or methyl amyl ketone is preferred.
As the cyclic ketone, methylcyclohexanone, isophorone, cyclopentanone, or cyclohexanone is preferred.
As the lactone, γ-butyrolactone is preferred.
As the alkylene carbonate, propylene carbonate is preferred.

Component (M2) is more preferably propylene glycol monomethyl ether (PGME), ethyl lactate, ethyl 3-ethoxypropionate, methyl amyl ketone, cyclohexanone, butyl acetate, pentyl acetate, γ-butyrolactone, or propylene carbonate.

In addition to the above-mentioned components, the solvent may include an ester solvent having 7 or more carbon atoms (preferably 7 to 14, more preferably 7 to 12, even more preferably 7 to 10) and having 2 or less heteroatoms. It is also preferable to include.
Examples of ester solvents having 7 or more carbon atoms and 2 or less heteroatoms include amyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, pentyl propionate, hexyl propionate, butyl propionate, and isobutyl isobutyrate. , heptyl propionate, or butyl butanoate are preferred, and isoamyl acetate is more preferred.

The component (M2) preferably has a flash point (hereinafter also referred to as fp) of 37° C. or higher. Such components (M2) include propylene glycol monomethyl ether (fp: 47°C), ethyl lactate (fp: 53°C), ethyl 3-ethoxypropionate (fp: 49°C), and methyl amyl ketone (fp: 42°C). ), cyclohexanone (fp: 44°C), pentyl acetate (fp: 45°C), methyl 2-hydroxyisobutyrate (fp: 45°C), γ-butyrolactone (fp: 101°C), or propylene carbonate (fp: 132°C) is preferred. Among these, propylene glycol monoethyl ether, ethyl lactate, pentyl acetate, or cyclohexanone are more preferred, and propylene glycol monoethyl ether or ethyl lactate is even more preferred.
In addition, the "flash point" here means the value described in the reagent catalog of Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich.

Preferably, the solvent contains component (M1). It is more preferable that the solvent consists essentially of component (M1) only, or is a mixed solvent of component (M1) and other components. In the latter case, it is more preferable that the solvent contains both component (M1) and component (M2).
The mass ratio (M1/M2) of component (M1) and component (M2) is preferably within the range of "100/0" to "15/85", and is preferably within the range of "100/0" to "40/60". ”, and even more preferably within the range of “100/0” to “60/40”. That is, it is preferable that the solvent consists only of component (M1) or contains both component (M1) and component (M2), and the mass ratio thereof is as follows. That is, in the latter case, the mass ratio of component (M1) to component (M2) is preferably 15/85 or more, more preferably 40/60 or more, and even more preferably 60/40 or more. preferable. If such a configuration is adopted, it becomes possible to further reduce the number of development defects.

Note that when the solvent contains both component (M1) and component (M2), the mass ratio of component (M1) to component (M2) is, for example, 99/1 or less.

When the solvent further contains components other than components (M1) and (M2), the content of components other than components (M1) and (M2) is preferably 5 to 30% by mass based on the total amount of the solvent.

The content of the solvent in the resist composition of the present invention is preferably determined so that the solid content concentration is 0.5 to 30% by mass, and 1 to 20% by mass in terms of better coating properties. It is more preferable to set

[Surfactant]
The resist composition of the present invention may contain a surfactant. When a surfactant is included, a pattern with better adhesion and fewer development defects can be formed.
The surfactant is preferably a fluorine-based and/or silicon-based surfactant.
Examples of the fluorine-based and/or silicon-based surfactants include the surfactants disclosed in paragraphs [0218] and [0219] of International Publication No. 2018/193954.

These surfactants may be used alone or in combination of two or more.

When the resist composition of the present invention contains a surfactant, the content of the surfactant is preferably 0.0001 to 2% by mass, and 0.0005 to 1% by mass based on the total solid content of the composition. More preferred.

Moreover, the present invention
(A) an onium salt compound;
(B1) Phenolic hydroxyl group, carboxyl group, -SO ₂ NHR ^N (R ^N is a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group), an amide group, a carbonylimide group, a sulfonylimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O)NHSO ₂ R ^P (R ^P is an alkyl group or an aryl group) a polymer having a repeating unit comprising at least one group selected from the group consisting of
The present invention also relates to an actinic ray-sensitive or radiation-sensitive resin composition in which the polymer has a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2).

In general formula (1),
Y represents a hydrogen atom or a hydrocarbon group.
A ² represents an aromatic ring group having an electron donating group. However, the electron donating group does not correspond to the at least one group.

(A) Onium salt compound is as described above.
The polymer (B1) is a preferred embodiment of the polymer (B).
Phenolic hydroxyl group, carboxyl group, -SO ₂ NHR ^N (R ^N represents a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group) ), an amide group, a carbonylimide group, a sulfonylimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O)NHSO ₂ R ^P (R ^P represents an alkyl group or an aryl group ) is an "acidic group having an acidic proton" in the above-mentioned polymer (B).
Moreover, each group in general formula (1) and general formula (2) is synonymous with each group in general formula (1) and general formula (2) of the said polymer (B).
The repeating unit containing an acidic group having an acidic proton may be a repeating unit represented by the above general formula (1), a repeating unit represented by the above general formula (2), or the above general formula (2). Although other repeating units different from formulas (1) and (2) may be used, at least any of the repeating units represented by the above general formula (1) and the repeating unit represented by the above general formula (2) One of them is preferable, and a repeating unit represented by the above general formula (1) is more preferable.

The polymer preferably contains a repeating unit represented by the above general formula (1-2) and a repeating unit represented by the above general formula (2-2).
The above-mentioned polymer may contain repeating units other than the above-mentioned repeating units within a range that does not impede the effects of the present invention. Examples of other repeating units include those similar to other repeating units that the polymer (B) may contain.
The content of the repeating unit represented by the above general formula (1) and the content of the repeating unit represented by the above general formula (2) are determined by the above general formula (1) in the above polymer (B). The content of the repeating unit represented by the formula (2) is the same as the content of the repeating unit represented by the above general formula (2). Moreover, the content of other repeating units is also the same as the content of other repeating units in the above polymer (B).

[Resist film, pattern formation method]
The present invention also relates to a resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition.
The present invention also provides a step of forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition, a step of exposing the resist film, and a step of applying a developer to the exposed resist film. It also relates to a pattern forming method, which comprises a step of developing using a pattern forming method.

Although the procedure of the pattern forming method using the above resist composition is not particularly limited, it is preferable to include the following steps.
Step 1: Step of forming a resist film on a substrate using a resist composition Step 2: Step of exposing the resist film Step 3: Step of developing the exposed resist film using a developer Below, each of the above The process steps will be explained in detail.

<Step 1: Resist film formation step>
Step 1 is a step of forming a resist film on a substrate using a resist composition.
The definition of the resist composition is as described above.

Examples of methods for forming a resist film on a substrate using a resist composition include a method of applying a resist composition onto a substrate.
Note that it is preferable to filter the resist composition as necessary before coating. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.05 μm or less, and even more preferably 0.03 μm or less. Moreover, the filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

The resist composition can be applied onto a substrate (eg, silicon, silicon dioxide coated), such as those used in the manufacture of integrated circuit devices, by any suitable application method, such as a spinner or coater. The coating method is preferably spin coating using a spinner. The rotation speed during spin coating using a spinner is preferably 1000 to 3000 rpm.
After applying the resist composition, the substrate may be dried to form a resist film. Note that, if necessary, various base films (inorganic film, organic film, antireflection film) may be formed under the resist film.

Examples of the drying method include a method of drying by heating. Heating can be carried out using a means provided in an ordinary exposure machine and/or developing machine, or may be carried out using a hot plate or the like. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, even more preferably 80 to 130°C. The heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, even more preferably 60 to 600 seconds.

The thickness of the resist film is not particularly limited, but is preferably 10 to 120 nm from the standpoint of forming fine patterns with higher precision. Among these, in the case of EUV exposure and EB exposure, the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. Further, in the case of ArF immersion exposure, the thickness of the resist film is more preferably 10 to 120 nm, and even more preferably 15 to 90 nm.

Note that a top coat may be formed on the upper layer of the resist film using a top coat composition.
Preferably, the top coat composition does not mix with the resist film and can be uniformly applied to the upper layer of the resist film. The top coat is not particularly limited, and a conventionally known top coat can be formed by a conventionally known method. Can be formed.
For example, it is preferable to form a top coat containing a basic compound as described in JP-A-2013-061648 on the resist film. Specific examples of basic compounds that may be included in the top coat include basic compounds that may be included in the resist composition.
It is also preferable that the top coat contains a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond.

<Step 2: Exposure step>
Step 2 is a step of exposing the resist film.
Examples of the exposure method include a method of irradiating the formed resist film with actinic rays or radiation through a predetermined mask.
Actinic light or radiation includes infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams, preferably 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to Deep ultraviolet light with a wavelength of 200 nm, specifically KrF excimer laser (248 nm), ArF excimer laser (193 nm), _F2 excimer laser (157 nm), EUV (13 nm), X-rays, and electron beams.

After exposure, it is preferable to perform post-exposure heat treatment (also referred to as post-exposure bake) before development. The post-exposure heat treatment accelerates the reaction in the exposed area, resulting in better sensitivity and pattern shape.
The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, even more preferably 80 to 130°C.
The heating time is preferably 10 to 1000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.
Heating can be carried out using means provided in a normal exposure machine and/or developing machine, and may be carried out using a hot plate or the like.

<Step 3: Development step>
Step 3 is a step of developing the exposed resist film using a developer to form a pattern.
The developer is preferably a developer containing an organic solvent (hereinafter also referred to as an organic developer).

Development methods include, for example, a method in which the substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and the substrate is left still for a certain period of time for development (paddle method). ), a method of spraying the developer onto the substrate surface (spray method), and a method of continuously discharging the developer while scanning the developer discharge nozzle at a constant speed onto the rotating substrate (dynamic dispensing method). can be mentioned.
Furthermore, after the step of developing, a step of stopping the development may be carried out while substituting another solvent.
The development time is not particularly limited as long as the resin in the unexposed areas is sufficiently dissolved, and is preferably 10 to 300 seconds, more preferably 20 to 120 seconds.
The temperature of the developer is preferably 0 to 50°C, more preferably 15 to 35°C.

The organic developer is a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents. It is preferable to have one.

A plurality of the above-mentioned solvents may be mixed together, or may be mixed with a solvent other than the above-mentioned ones or water. The water content of the developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, even more preferably less than 10% by mass, and particularly preferably substantially free of water.
The content of the organic solvent in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, and 90% by mass or more and 100% by mass, based on the total amount of the developer. The following is more preferable, and 95% by mass or more and 100% by mass or less is particularly preferable.

<Other processes>
The pattern forming method preferably includes a step of cleaning using a rinsing liquid after step 3.

The rinsing solution used in the rinsing step after the development step using an organic developer is not particularly limited as long as it does not dissolve the pattern, and solutions containing common organic solvents can be used. The rinsing liquid contains at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. is preferred.

The method of the rinsing process is not particularly limited, and examples include a method in which the rinsing liquid is continuously discharged onto the substrate rotating at a constant speed (rotary coating method), and a method in which the substrate is immersed in a tank filled with the rinsing liquid for a certain period of time. (dip method), and a method of spraying a rinsing liquid onto the substrate surface (spray method).
Further, the pattern forming method of the present invention may include a heating step (Post Bake) after the rinsing step. In this step, the developer and rinse solution remaining between patterns and inside the patterns due to baking are removed. This step also has the effect of smoothing the resist pattern and improving surface roughness of the pattern. The heating step after the rinsing step is usually carried out at 40 to 250°C (preferably 90 to 200°C) for 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

Further, the substrate may be etched using the formed pattern as a mask. That is, the pattern formed in step 3 may be used as a mask to process the substrate (or the lower film and the substrate) to form a pattern on the substrate.
The method of processing the substrate (or the lower layer film and the substrate) is not particularly limited, but by performing dry etching on the substrate (or the lower layer film and the substrate) using the pattern formed in step 3 as a mask, the substrate is processed. A method of forming a pattern is preferred. The dry etching is preferably oxygen plasma etching.

The resist composition and various materials used in the pattern forming method of the present invention (e.g., solvent, developer, rinsing liquid, composition for forming an antireflection film, composition for forming a top coat, etc.) do not contain impurities such as metals. Preferably, it does not contain. The content of impurities contained in these materials is preferably 1 mass ppm or less, more preferably 10 mass ppt or less, even more preferably 100 mass ppt or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. Here, examples of metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, Zn, etc. are mentioned.

Examples of methods for removing impurities such as metals from various materials include filtration using a filter. Details of filtration using a filter are described in paragraph [0321] of International Publication No. 2020/004306.

In addition, methods for reducing impurities such as metals contained in various materials include, for example, selecting raw materials with low metal content as raw materials constituting various materials, and filtering raw materials constituting various materials. and a method in which distillation is carried out under conditions where contamination is suppressed as much as possible by lining the inside of the apparatus with Teflon (registered trademark).

In addition to filter filtration, impurities may be removed using an adsorbent, or a combination of filter filtration and an adsorbent may be used. As the adsorbent, known adsorbents can be used, such as inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon. In order to reduce impurities such as metals contained in the various materials mentioned above, it is necessary to prevent metal impurities from being mixed in during the manufacturing process. Whether metal impurities have been sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of metal components contained in the cleaning liquid used to clean the manufacturing equipment. The content of metal components contained in the cleaning solution after use is preferably 100 parts per trillion or less, more preferably 10 parts per trillion or less, and even more preferably 1 parts per trillion or less.

Further, the resist composition may contain water as an impurity. When water is contained as an impurity, the water content is preferably as small as possible, but may be contained in an amount of 1 to 30,000 ppm by mass based on the entire resist composition.
Further, the resist composition may contain residual monomers (for example, monomers derived from raw material monomers used in the synthesis of polymer (B)) as impurities. When a residual monomer is contained as an impurity, the content of the residual monomer is preferably as small as possible, but it may be contained in an amount of 1 to 30,000 ppm by mass based on the total solid content of the resist composition.

Conductive compounds are added to organic processing solutions such as rinse solutions to prevent damage to chemical piping and various parts (filters, O-rings, tubes, etc.) due to static electricity charging and subsequent electrostatic discharge. You may. The conductive compound is not particularly limited, and for example, methanol may be mentioned. The amount added is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less in terms of maintaining favorable development characteristics or rinsing characteristics.
Examples of chemical liquid piping include SUS (stainless steel), polyethylene or polypropylene treated with antistatic treatment, or various types of piping coated with fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.). can be used. Similarly, for the filter and O-ring, antistatically treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) can be used.

[Manufacturing method of electronic device]
The present invention also relates to an electronic device manufacturing method including the above-described pattern forming method, and an electronic device manufactured by this manufacturing method.
The electronic device of the present invention is preferably installed in electrical and electronic equipment (home appliances, office automation (OA), media-related equipment, optical equipment, communication equipment, etc.).

[Polymer]
The present invention provides a polymer having a repeating unit containing an acidic group having an acidic proton, which is described as a preferable embodiment of the above-mentioned polymer (B), and the repeating unit represented by the above general formula (1), and a polymer containing a repeating unit represented by the above general formula (2), wherein the acidic group is a phenolic hydroxyl group, a carboxyl group, -SO ₂ NHR ^N (R ^N is a hydrogen atom, an alkyl group, aryl group, alkylcarbonyl group, arylcarbonyl group, alkoxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, cyano group), amide group, carbonylimide group, sulfonylimide group, thiol substituted on a member atom of an aromatic ring It also relates to polymers representing at least one group selected from the group consisting of the group -C(=O)NHSO ₂ R ^P (R ^P represents an alkyl group or an aryl group).

The repeating unit containing an acidic group having an acidic proton may be a repeating unit represented by the above general formula (1), a repeating unit represented by the above general formula (2), or the above general formula (2). Although other repeating units different from formulas (1) and (2) may be used, at least any of the repeating units represented by the above general formula (1) and the repeating unit represented by the above general formula (2) One of them is preferable, and a repeating unit represented by the above general formula (1) is more preferable.

The present invention will be described in more detail below based on Examples. The materials, usage amounts, proportions, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the Examples shown below.

[Various components of actinic ray-sensitive or radiation-sensitive resin composition]
[Polymer (B)]
The polymers shown in Table 2 (B-1 to B-23 and RB-1 to RB-3) are shown below.
B-3 was synthesized by the synthesis method (Synthesis Example 1) described below. B-1 to 2, B-4 to B-23, and RB-1 to RB-3 were synthesized according to Synthesis Example 1 or by known methods. Note that polymers RB-1 to RB-3 correspond to comparative polymers.
Table 1 shows the compositions of Polymers B-1 to B-23 and RB-1 to RB-3 (types of raw material monomers, composition ratios of repeating units (mol% ratio), weight average molecular weights (Mw), and degree of dispersion). (Mw/Mn)).
The weight average molecular weight (Mw) and dispersity (Mw/Mn) of Polymers B-1 to B-23 and RB-1 to RB-3 were measured by GPC (carrier: tetrahydrofuran (THF)) (polystyrene (converted quantity). Further, the composition ratio (mol% ratio) of the polymer was measured by ¹³ C-NMR (Nuclear Magnetic Resonance).

In polymers B-1 to B-23 and RB-1 to RB-3 in Table 1 above, each raw material monomer is as follows.
In addition, the raw material monomer of repeating unit 1 in Table 1 is selected from the following monomers M-1 to M-4, M-7, M-8, M-13, M-16, M-18 and M-19. This is a raw material monomer for the repeating unit represented by the above general formula (1). The raw material monomer for repeating unit 2 in Table 1 is a raw material monomer for the repeating unit represented by the above general formula (2) selected from the following monomers Ma-1 to Ma-9. The raw material monomer for repeating unit 3 in Table 1 is a monomer selected from the following monomers N-1, N-3, and N-5 to N-7.
In addition, the raw material monomer M-20 of repeating unit 3 in Table 1 is the following monomer M-20.

Note that in M-1 to M-20, the σp values of each group shown as an electron-donating group were all less than 0.

Under a nitrogen stream, 5.33 g of cyclohexanone was placed in a three-necked flask and heated to 85°C. Next, in the three-necked flask, 11.92 g of monomer M-3, 6.08 g of monomer Ma-1, and 20% by mass of polymerization initiator V-601 (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) were added. A mixed solution of 0.58 g of cyclohexanone solution and 21.1 g of cyclohexanone was added dropwise over 4 hours, and after completion of the dropwise addition, the reaction was further carried out at 85° C. for 2 hours. After the reaction was completed, the reaction solution was allowed to cool. Next, the reaction solution after being left to cool was dropped into 300 g of stirred heptane/ethyl acetate (9/1), and the powder precipitated by the dropping was collected by filtration and dried to obtain resin B-3 (7. 5g) was obtained.

Regarding the above resin B-3, the composition ratio (molar ratio) of repeating units determined by ¹³ C-NMR (nuclear magnetic resonance) method is repeating units derived from monomer M-3/repeat units derived from monomer Ma-1. =48/52. Furthermore, the weight average molecular weight of the obtained resin B-3 measured by GPC was 43,000 in terms of standard polystyrene, and the degree of dispersion (Mw/Mn) was 1.73.

[Onium salt compound (A)]
The structures of the onium salt compounds (A-1 to A-12) shown in Table 2 are shown below. Note that the onium salt compounds (A-1 to A-12) all correspond to photodegradable onium salt compounds.

〔solvent〕
The solvents shown in Table 2 are shown below.
G1: Propylene glycol monomethyl ether acetate (PGMEA)
G2: Propylene glycol monomethyl ether (PGME)
G3: Diacetone alcohol (DAA)
G4: γ-butyrolactone (GBL)
G5: Ethyl lactate (EL)
G6: Dimethylformamide G7: Cyclohexanone G8: Cyclopentanone

[Preparation of actinic ray-sensitive or radiation-sensitive resin composition]
Each component other than the solvent shown in Table 2 was mixed so that the solid content concentration was 1.3% by mass. Next, the resulting mixed solution was filtered through a polyethylene filter having a pore size of 0.03 μm to prepare a resist composition. Here, solid content means all components other than the solvent. The obtained resist compositions were used in Examples and Comparative Examples.

[Pattern formation and evaluation]
[Pattern formation and evaluation by EUV exposure: Examples 1 to 24, Comparative Examples 1 to 5]
<Pattern formation>
A lower layer film forming composition SHB-A940 (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied onto a silicon wafer and baked at 205° C. for 60 seconds to form a lower layer film with a thickness of 20 nm. A resist composition shown in Table 2 was applied thereon and baked at 100° C. for 60 seconds to form a resist film with a thickness of 30 nm. As a result, a silicon wafer having a resist film was formed.
A silicon wafer having a resist film obtained by the above procedure was exposed using an EUV exposure device (manufactured by Exitech, Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36). Pattern irradiation was performed. Note that a mask with a line:space ratio of 1:1 was used as the reticle.
The exposed resist film was baked at 90° C. for 60 seconds, developed with butyl acetate for 30 seconds, rinsed with butyl acetate, and spin-dried to obtain a pattern.

<Sensitivity>
The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-9380II manufactured by Hitachi, Ltd.). The exposure amount when resolving a 1:1 line-and-space resist pattern with a line width of 14 nm was defined as the sensitivity (Eop). The smaller this value, the higher the sensitivity.

<LWR performance>
A length-measuring scanning electron microscope (SEM (S-9380II manufactured by Hitachi, Ltd.)) was used to measure the 14 nm (1:1) line-and-space pattern resolved at the exposure dose that shows the sensitivity (Eop) above. Observation was made from the top of the pattern. The line width of the pattern was observed at 100 arbitrary points, its standard deviation (σ) was determined, and the measurement variation in line width was evaluated using 3σ (nm). The smaller the value, the better the performance.

From the results shown in Table 2, it is clear that the resist compositions of Examples have excellent sensitivity and LWR performance of the formed patterns.

[Pattern formation and evaluation by EB exposure: Examples 1A to 24A]
Even when a resist film was formed using each of the resist compositions of Examples and pattern formation was performed by exposing it to electron beams, results with the same tendency as when pattern formation was performed by EUV exposure were obtained. It was done.

According to the present invention, actinic light can be used to form patterns with excellent sensitivity and excellent LWR performance in the formation of ultra-fine patterns (for example, line-and-space patterns with a line width of 15 nm or less, hole patterns with a hole diameter of 15 nm or less, etc.). A radiation-sensitive or radiation-sensitive resin composition can be provided.
Further, the present invention can provide a resist film, a pattern forming method, and an electronic device manufacturing method using the actinic ray-sensitive or radiation-sensitive resin composition.
Moreover, the present invention can provide a polymer useful for the actinic ray-sensitive or radiation-sensitive resin composition.

Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application (Japanese Patent Application No. 2022-138712) filed on August 31, 2022, the contents of which are incorporated herein by reference.

Claims

(A) an onium salt compound;
(B) a polymer having a repeating unit containing an acidic group having an acidic proton and whose main chain decomposes upon irradiation with actinic rays or radiation;
The polymer has a repeating unit represented by the following general formula (1),
The acidic group is a phenolic hydroxyl group, a carboxyl group, -SO 2 NHR N ( RN is a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group) , represents a cyano group), an amide group, a carbonylimide group, a sulfonylimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O)NHSO 2 R P (R P is an alkyl group or an aryl group).An actinic ray-sensitive or radiation-sensitive resin composition.

In general formula (1),
Y represents a hydrogen atom or a hydrocarbon group.
A 2 represents an aromatic ring group having an electron donating group. However, the electron donating group does not correspond to the acidic group.
The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, wherein the polymer has a repeating unit represented by the following general formula (2).

In general formula (2),
X represents a halogen atom.
L 1 represents -O- or -NR 1 -. R 1 represents a hydrogen atom or an organic group.
A 1 represents a hydrogen atom or an organic group.
R 0 represents a hydrogen atom or an organic group. R 0 may be linked with A 1 or R 1 to form a ring.
Actinic ray-sensitive according to claim 1 or 2, wherein the polymer contains a repeating unit represented by the following general formula (1-2) and a repeating unit represented by the following general formula (2-2). Or a radiation-sensitive resin composition.

In general formula (1-2),
Y represents a hydrogen atom or a hydrocarbon group.
R 2 represents an acidic group having the aforementioned acidic proton. When a plurality of R 2s exist, the plurality of R 2s may be the same or different.
R 3 represents an electron donating group. When a plurality of R 3s exist, the plurality of R 3s may be the same or different. However, the electron donating group does not correspond to the acidic group.
L 2 represents a single bond or a divalent linking group.
m represents an integer from 1 to 4.
n represents an integer from 1 to 4. However, 1≦m+n≦5 is satisfied.

In general formula (2-2),
X represents a halogen atom.
A 1 represents a hydrogen atom or an organic group.
R 0 represents a hydrogen atom or an organic group. R 0 may be connected to A 1 to form a ring.
The actinic ray-sensitive or sensitive method according to claim 1 or 2, wherein the electron-donating group is at least one group selected from an alkyl group, an alkoxy group, an alkylthio group, a dialkylamino group, and a monoalkylamino group. Radioactive resin composition.
The actinic ray-sensitive material according to claim 1 or 2, wherein the content of the onium salt compound is 0.1 to 20% by mass based on the total solid content of the actinic ray-sensitive or radiation-sensitive resin composition. radiation-sensitive resin composition.
A polymer having a repeating unit containing an acidic group having an acidic proton, comprising a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2),
The acidic group is a phenolic hydroxyl group, a carboxyl group, -SO 2 NHR N ( RN is a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group) , represents a cyano group), an amide group, a carbonylimide group, a sulfonylimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O)NHSO 2 R P (R P is an alkyl group or an aryl group).

In general formula (1),
Y represents a hydrogen atom or a hydrocarbon group.
A 2 represents an aromatic ring group having an electron donating group. However, the electron-donating group does not correspond to the acidic group.

In general formula (2),
X represents a halogen atom.
L 1 represents -O- or -NR 1 -. R 1 represents a hydrogen atom or an organic group.
A 1 represents a hydrogen atom or an organic group.
R 0 represents a hydrogen atom or an organic group. R 0 may be linked with A 1 or R 1 to form a ring.
The polymer according to claim 6, wherein the polymer contains a repeating unit represented by the following general formula (1-2) and a repeating unit represented by the following general formula (2-2).

In general formula (1-2),
Y represents a hydrogen atom or a hydrocarbon group.
R 2 represents an acidic group having the aforementioned acidic proton. When a plurality of R 2s exist, the plurality of R 2s may be the same or different.
R 3 represents an electron donating group. When a plurality of R 3s exist, the plurality of R 3s may be the same or different. However, the electron-donating group does not correspond to the acidic group.
L 2 represents a single bond or a divalent linking group.
m represents an integer from 1 to 4.
n represents an integer from 1 to 4. However, 1≦m+n≦5 is satisfied.

In general formula (2-2),
X represents a halogen atom.
A 1 represents a hydrogen atom or an organic group.
R 0 represents a hydrogen atom or an organic group. R 0 may be connected to A 1 to form a ring.
(A) an onium salt compound;
(B1) Phenolic hydroxyl group, carboxyl group, -SO 2 NHR N (R N is a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group), an amide group, a carbonylimide group, a sulfonylimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O)NHSO 2 R P (R P is an alkyl group or an aryl group) a polymer having a repeating unit comprising at least one group selected from the group consisting of
An actinic ray-sensitive or radiation-sensitive resin composition, wherein the polymer has a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2).

In general formula (1),
Y represents a hydrogen atom or a hydrocarbon group.
A 2 represents an aromatic ring group having an electron donating group. However, the electron donating group does not correspond to the at least one group.

In general formula (2),
X represents a halogen atom.
L 1 represents -O- or -NR 1 -. R 1 represents a hydrogen atom or an organic group.
A 1 represents a hydrogen atom or an organic group.
R 0 represents a hydrogen atom or an organic group. R 0 may be linked with A 1 or R 1 to form a ring.
A resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1, 2, and 8.
forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1, 2, and 8;
a step of exposing the resist film;
A pattern forming method comprising the step of developing the exposed resist film using a developer.
A method for manufacturing an electronic device, comprising the pattern forming method according to claim 10.