WO2024128040A1

WO2024128040A1 - Active-ray-sensitive or radiation-sensitive resin composition, resist film, pattern formation method, and electronic device production method

Info

Publication number: WO2024128040A1
Application number: PCT/JP2023/043179
Authority: WO
Inventors: 洋平石地; 洋佑戸次; 佑真楜澤; 平村上; 研由後藤
Original assignee: 富士フイルム株式会社
Priority date: 2022-12-12
Filing date: 2023-12-01
Publication date: 2024-06-20
Also published as: TW202432632A

Abstract

Provided are: an active-ray-sensitive or radiation-sensitive resin composition including (A) an onium salt compound and (B) a polymer having a repeating unit expressed by a specific general formula (1) and a repeating unit expressed by a specific general formula (3); a resist film formed using the active-ray-sensitive or radiation-sensitive resin composition; a pattern formation method comprising a step for forming a resist film on a substrate using the active-ray-sensitive or radiation-sensitive resin composition, a step for exposing the resist film, and a step for developing the light-exposed resist film using a developing solution; and an electronic device production method.

Description

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

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, and a method for manufacturing an electronic device.

After resists for KrF excimer lasers (248 nm), a pattern formation method using chemical amplification has been used to compensate for the loss of sensitivity due to light absorption. For example, in the positive-tone chemical amplification method, a photoacid generator contained in the exposed area is first decomposed by light irradiation to generate acid. Then, during a post-exposure bake (PEB) process, the catalytic action of the generated acid changes the alkali-insoluble groups of the resin contained in the actinic ray-sensitive or radiation-sensitive resin composition to alkali-soluble groups, thereby changing the solubility in the developer. After that, development is performed using, for example, a basic aqueous solution. This removes the exposed area to obtain the desired pattern.

Also known is a pattern formation method using a polymer whose main chain is cleaved upon exposure to actinic rays or radiation.
For example, Patent Document 1 describes a positive resist composition that contains an ionic compound and a resin that has a repeating unit having an interactive group that interacts with the ionic group in the ionic compound, and whose main chain is decomposed by irradiation with X-rays, electron beams, or extreme ultraviolet rays.

International Publication No. 2021/153466

Recently, in order to miniaturize semiconductor elements, the wavelength of exposure light sources has become shorter and the numerical aperture (NA) of projection lenses has become higher. For example, pattern formation methods using extreme ultraviolet (EUV light: Extreme Ultraviolet) and electron beam (EB: Electron Beam) as light sources are also being considered. Under these circumstances, further improvements in the performance of actinic ray-sensitive or radiation-sensitive resin compositions are required.

Therefore, an object of the present invention is to provide an actinic ray-sensitive or radiation-sensitive resin composition that is excellent in sensitivity and resolution in the formation of ultrafine patterns (for example, a line-and-space pattern with a line width of 20 nm or less, a hole pattern with a hole diameter of 20 nm or less, etc.).
Another object of the present invention is to provide a resist film, a pattern forming method, and a method for producing an electronic device, each of which uses the actinic ray-sensitive or radiation-sensitive resin composition.

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

[1]
(A) an onium salt compound, and
(B) An actinic ray-sensitive or radiation-sensitive resin composition comprising a polymer having a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (3):

In the general formula (1),
X represents a chlorine atom, a bromine atom, or an iodine atom.
A ₁ represents an organic group that satisfies the condition that the SP value in the compound represented by A ₁ -O-C(=O)-CH=CH ₂ is 21.00 MPa ^1/2 or more.
R ₀ represents a hydrogen atom or an organic group.

In the general formula (3),
Y represents a hydrogen atom or a methyl group.
_A2 represents an aromatic ring group.

[2]
The actinic ray-sensitive or radiation _- sensitive resin composition according to [1], wherein A ₁ in the general formula (1) is an organic group that satisfies the condition that the SP value in the compound represented by A ₁ -O-C(═O)-CH═CH 2 is 21.00 to 25.00 MPa ^1/2 .

[3]
The actinic ray-sensitive or radiation-sensitive resin composition according to [1] or [2], wherein the polymer has a repeating unit containing an acidic group having an acidic proton.

[4]
The actinic ray-sensitive or radiation-sensitive resin composition according to [3], wherein the repeating unit containing an acidic group having an acidic proton is a repeating unit represented by general formula (1), and A ₁ in general formula (1) represents an organic group containing the acidic group having an acidic proton.

[5]
The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [4], wherein A ₂ in the general formula (3) is an aromatic ring group having an electron-donating group.
[6]
The actinic ray-sensitive or radiation-sensitive resin composition according to [5], wherein the repeating unit represented by the above general formula (3) is a repeating unit represented by the following general formula (4):

In general formula (4),
Y represents a hydrogen atom or a methyl group.
EDG represents an electron donating group.
_A3 represents a substituent.
m represents an integer of 1 to 5.
p represents an integer of 0 to 5, provided that 1≦m+p≦5 is satisfied.

[7]
(A) an onium salt compound, and
(B) An actinic ray-sensitive or radiation-sensitive resin composition comprising a polymer having a repeating unit represented by the following general formula (2) and a repeating unit represented by the following general formula (3):

In the general formula (2),
X represents a chlorine atom, a bromine atom, or an iodine atom.
R ₀ represents a hydrogen atom or an organic group.
L represents a single bond or a divalent linking group.
A ₁₁ represents a group represented by any one of the following general formulas (2a) to (2d).

In general formula (2a),
Z represents a carbon atom or a nitrogen atom.
AN represents a nitrogen-containing aromatic group.
In general formula (2b),
R ₁ represents a hydrogen atom or a substituent.
_R2 represents a substituent.
_R1 and _R2 may be bonded to each other to form a ring.
In general formula (2c),
_R3 represents an amide group, an imido group, an alkylcarbonyl group, an arylcarbonyl group, a cyano group, a carboxyl group, or a hydroxyl group.
n represents an integer of 1 to 5.
When n is an integer of 2 to 5, multiple R ₃ 's may be the same or different.
In general formula (2d),
L _A represents -C(=O)- or -S(=O) ₂ -.
_R4 represents a hydrogen atom, an alkyl group, an aryl group, or a nitrogen-containing aromatic group.
_R5 represents an alkyl group, an aryl group, or a nitrogen-containing aromatic group.

[8]
A resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [7].

[9]
forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of items [1] to [7];
exposing the resist film to light;
and developing the exposed resist film with a developer.

[10]
A method for manufacturing an electronic device, comprising the pattern formation method according to [9].

According to the present invention, it is possible to provide an actinic ray-sensitive or radiation-sensitive resin composition that is excellent in sensitivity and resolution in forming ultrafine patterns (for example, a line-and-space pattern having a line width of 20 nm or less, or a hole pattern having a hole diameter of 20 nm or less).
Furthermore, according to the present invention, there can be provided a resist film, a pattern forming method, and a method for producing an electronic device, each of which uses the actinic ray-sensitive or radiation-sensitive resin composition.

The present invention will be described in detail below.
The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment.
In the present specification, the notation of groups (atomic groups) that does not indicate whether they are substituted or unsubstituted includes both unsubstituted and substituted groups, unless it is contrary to the spirit of the present invention. For example, the term "alkyl group" includes not only alkyl groups that do not have a substituent (unsubstituted alkyl groups), but also alkyl groups that have a substituent (substituted alkyl groups). In addition, the term "organic group" in the present specification refers to a group that contains at least one carbon atom.
Unless otherwise specified, the substituent is preferably a monovalent substituent.
In this specification, "actinic rays" or "radiation" refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV: Extreme Ultraviolet), X-rays, electron beams (EB: Electron Beam), etc. In this specification, "light" refers to actinic rays or radiation.
In this specification, unless otherwise specified, "exposure" includes not only exposure to the emission line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light, X-rays, EUV light, and the like, but also drawing with particle beams such as electron beams and ion beams.
In this specification, the word "to" is used to mean that the numerical values before and after it are included as the lower limit and upper limit.
The bonding direction of the divalent group described in this specification is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "X-Y-Z", Y may be -CO-O- or -O-CO-. In addition, 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 called molecular weight distribution) (Mw/Mn) of the resin are defined as polystyrene equivalent values measured using a Gel Permeation Chromatography (GPC) device (Tosoh HLC-8120GPC) (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: refractive index detector).

In this specification, the acid dissociation constant (pKa) refers to the pKa in an aqueous solution, and is specifically a value calculated using the following software package 1 based on a database of Hammett's substituent constants and publicly known literature values. All pKa values described in this specification 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 obtained by molecular orbital calculation. A specific example of this method is a method of calculating H ⁺ 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 literature, and the calculation method is not limited to this. There are several software programs that can perform DFT, and Gaussian16 is an example.

As described above, the pKa in this specification refers to a value calculated using the software package 1 based on a database of Hammett's substituent constants and known literature values. However, when the pKa cannot be calculated by this method, a value obtained by Gaussian 16 based on DFT (density functional theory) is adopted.
In addition, the pKa in this specification refers to "pKa in an aqueous solution" as described above, but when the pKa in an aqueous solution cannot be calculated, "pKa in a dimethyl sulfoxide (DMSO) solution" will be adopted.

In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

In this specification, solids refers to components that form a resist film and does not include solvents. In addition, any component that forms a resist film is considered to be a solid even if it is in liquid form.

[Actinic ray- or radiation-sensitive resin composition]
The present invention relates to
(A) an onium salt compound, and
(B) The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition comprising a polymer having a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (3):

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
(A) an onium salt compound, and
The present invention also relates to an actinic ray-sensitive or radiation-sensitive resin composition containing a polymer having a repeating unit represented by the following general formula (2) and a repeating unit represented by the following general formula (3):

In general formula (2a),
Z represents a carbon atom or a nitrogen atom.
AN represents a nitrogen-containing aromatic group.
In general formula (2b),
R ₁ represents a hydrogen atom or a substituent.
_R2 represents a substituent.
_R1 and _R2 may be bonded to each other to form a ring.
In general formula (2c),
_R3 represents an amide group, an imido group, an alkylcarbonyl group, an arylcarbonyl group, a cyano group, a carboxyl group, or a hydroxyl group.
n represents an integer of 1 to 5.
In general formula (2d),
L _A represents -C(=O)- or -S(=O) ₂ -.
_R4 represents a hydrogen atom, an alkyl group, an aryl group, or a nitrogen-containing aromatic group.
_R5 represents an alkyl group, an aryl group, or a nitrogen-containing aromatic group.

The actinic ray-sensitive or radiation-sensitive resin composition of the present invention is typically a resist composition. Hereinafter, the actinic ray-sensitive or radiation-sensitive resin composition of the present invention is also referred to as a "resist composition."

The resist composition of the present invention, having the above-mentioned structure, is excellent in sensitivity and resolution in the formation of ultrafine patterns. The reason for this is not clear in detail, but the present inventors speculate as follows.
The polymer (B) contained in the resist composition of the present invention has a repeating unit represented by the above general formula (1) and a repeating unit represented by the above general formula (3). Or, it has a repeating unit represented by the above general formula (2) and a repeating unit represented by the general formula (3). The polymer (B) having these repeating units becomes a polymer whose main chain is decomposed by irradiation with actinic rays or radiation.
In the repeating unit represented by the general formula (1), A ₁ in the general formula (1) has a high polarity, that is, the SP value in the compound represented by A ₁ -O-C(=O)-CH=CH ₂ is 21.00 MPa ^1/2 or more, and therefore the unexposed part of the resist film formed using the resist composition of the present invention is less soluble in the developer. In addition, in the repeating unit represented by the general formula (2), by making A ₁₁ in the general formula (2) a specific substituent, the unexposed part of the resist film formed using the resist composition of the present invention is less soluble in the developer. The developer is typically a developer containing an organic solvent. On the other hand, when exposed to light, the main chain of the polymer (B) decomposes and becomes more soluble in the developer. In other words, it is considered that the above action increases the dissolution contrast between the unexposed part and the exposed part in the resist film, resulting in excellent sensitivity and resolution.

According to the study by the present inventors, in the polymers which undergo main chain decomposition by irradiation with actinic rays or radiation, it is presumed that the main chain is decomposed and the ester bond directly connected to the main chain is partially decomposed by irradiation with actinic rays or radiation, and a decarboxylation reaction occurs. In this case, it is presumed that the polarity conversion effect of the polymer by the decarboxylation reaction is increased by selecting a group which is less soluble in a developer as A ₁ in general formula (1) or A ₁₁ in general formula (2), thereby obtaining better sensitivity and resolution.

Hereinafter, superior sensitivity of the resist composition and/or superior resolution of the pattern formed from the resist composition will also be referred to as "superior effects of the present invention."

First, the various components contained in the resist composition of the present invention will be explained below.

<Onium Salt Compound (A)>
The resist composition of the present invention contains an onium salt compound (A).
The onium salt compound (A) may be in the form of a low molecular weight compound or in the form of being incorporated into a part of a polymer. In addition, the form of a low molecular weight compound and the form of being incorporated into a part of a polymer may be used in combination.
When the onium salt compound (A) is in a form in which it is incorporated into a part of a polymer, it may be incorporated into a part of the polymer (B) or into a polymer different from the polymer (B).

The onium salt compound (A) may be a compound that decomposes when irradiated with actinic rays or radiation, or may be a compound that does not decompose. The compound that decomposes when irradiated with actinic rays or radiation may be a compound that decomposes when irradiated with actinic rays or radiation to generate an acid, or a compound that decomposes when irradiated with actinic rays or radiation to generate a base.
The onium salt compound (A) is preferably a compound having an onium salt structure that generates an acid upon irradiation with actinic rays or radiation (a photodecomposable onium salt compound).
When the resist composition contains an onium salt compound such as a photodegradable onium salt compound, the polymer (B) is likely to aggregate with the onium salt compound (A) in the unexposed area via the interactive group that may be contained in the polymer (B). On the other hand, when exposed to light, the onium salt compound (A) dissociates from the interactive group or the photodegradable onium salt compound is cleaved, so that the aggregated structure can be released. In other words, the above-mentioned action further increases the dissolution contrast between the unexposed area and the exposed area in the resist film, making the effect of the present invention more excellent.

The photodecomposable onium salt compound will now be described.
The photodecomposable onium salt compound is preferably a compound which has at least one salt structure moiety composed of an anion moiety and a cation moiety and which decomposes upon exposure to generate an acid (preferably an organic acid).
The above-mentioned salt structure portion of the photodecomposable onium salt compound is preferably composed of an organic cation portion and an organic anion portion having extremely low nucleophilicity, because it is easily decomposable upon exposure to light and has excellent organic acid generation properties.
The salt structure moiety may be a part or the whole of the photodecomposable onium salt compound. The case where the salt structure moiety is a part of the photodecomposable onium salt compound corresponds to, for example, a structure in which two or more salt structure moieties are linked together, such as the photodecomposable onium salt PG2 described later.
The number of salt structure moieties in the photodecomposable onium salt is not particularly limited, but is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3.

Examples of the organic acid generated from the photodecomposable onium salt compound by the action of exposure to light include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphorsulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, aralkyl carboxylic acids, etc.), carbonylsulfonylimide acids, bis(alkylsulfonyl)imide acids, and tris(alkylsulfonyl)methide acids.
In addition, the organic acid generated from the photodecomposable onium salt compound by the action of exposure may be a polyvalent acid having two or more acid groups. For example, when the photodecomposable onium salt compound is the photodecomposable onium salt compound PG2 described later, the organic acid generated by decomposition of the photodecomposable onium salt compound by exposure is a polyvalent acid having two or more acid groups.

In the photodecomposable onium salt compound, the cationic moiety constituting the salt structure moiety is preferably an organic cationic moiety, and among these, an organic cation represented by formula (ZaI) (cation (ZaI)) or an organic cation represented by formula (ZaII) (cation (ZaII)) as described below is preferred.

(Photodecomposition type onium salt compound PG1)
An example of a suitable embodiment of the photodecomposable onium salt compound is an onium salt compound represented by "M ⁺ X ^- ", which generates an organic acid upon exposure to light (hereinafter also referred to as "photodecomposable onium salt compound PG1").
In the compound represented by "M ⁺ X ^- ", M ⁺ represents an organic cation, and X ^- represents an organic anion.
The photodecomposable onium salt compound PG1 will now be described.

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

In the above formula (ZaI),
R ²⁰¹ , R ²⁰² and R ²⁰³ each independently represent an organic group.
The number of carbon atoms in the organic group represented by R ²⁰¹ , R ²⁰² , and R ²⁰³ is usually 1 to 30, and preferably 1 to 20. Two of R ²⁰¹ to R ²⁰³ may be bonded 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 bonding two of R ²⁰¹ to R ²⁰³ include an alkylene group (e.g., a butylene group and a pentylene group) and -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -.

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

First, the cation (ZaI-1) will be described.
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 aryl groups, or some of R ²⁰¹ to R ²⁰³ may be aryl groups, with the remainder being alkyl groups or cycloalkyl groups.
In addition, 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, which may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group in the ring. Examples of the group formed by bonding two of R ²⁰¹ to R ²⁰³ include alkylene groups in which one or more methylene groups may be substituted with oxygen atoms, sulfur atoms, ester groups, amide groups, and/or carbonyl groups (e.g., butylene group, pentylene group, or -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -).
Examples of the arylsulfonium cation include triarylsulfonium cations, diarylalkylsulfonium cations, aryldialkylsulfonium cations, diarylcycloalkylsulfonium cations, and aryldicycloalkylsulfonium cations.

The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure with an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the heterocyclic structure include a pyrrole residue, a furan residue, a thiophene residue, an indole residue, a benzofuran residue, and a 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 which the arylsulfonium cation optionally has is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, and more preferably, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, or a cyclohexyl group.

Preferred substituents that the aryl group, alkyl group, and cycloalkyl group of R ²⁰¹ to R ²⁰³ may have are each independently an alkyl group (e.g., 1 to 15 carbon atoms), a cycloalkyl group (e.g., 3 to 15 carbon atoms), an aryl group (e.g., 6 to 14 carbon atoms), an alkoxy group (e.g., 1 to 15 carbon atoms), a cycloalkylalkoxy group (e.g., 1 to 15 carbon atoms), a halogen atom (e.g., fluorine, iodine), a 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-mentioned substituent may further have a substituent if possible. For example, it is also preferred that the above-mentioned alkyl group has a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group.

Next, the cation (ZaI-2) will be described.
Cation (ZaI-2) is a cation in which R ²⁰¹ to R ²⁰³ in formula (ZaI) each independently represent an organic group not having an aromatic ring. Here, the aromatic ring also includes an aromatic ring containing a heteroatom.
The organic group not having an aromatic ring represented by R ²⁰¹ to R ²⁰³ generally has 1 to 30 carbon atoms, and preferably has 1 to 20 carbon atoms.
Each of R ²⁰¹ to R ²⁰³ independently represents preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and still more preferably a linear or branched 2-oxoalkyl group.

Examples of the alkyl group and cycloalkyl group for R ²⁰¹ to R ²⁰³ include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl groups), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl groups).
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 described.
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, a hydroxyl group, 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, and each of these rings may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
Examples of the 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.

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 includes alkylene groups such as butylene and pentylene, in which the methylene group may be substituted with a heteroatom such as an oxygen atom.
The groups formed by combining _R5c and _R6c , and _R5c and _Rx are 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 R _x and R _y may each have a substituent.

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

In formula (ZaI-4b),
l represents an integer of 0 to 2.
r represents an integer of 0 to 8.
R ₁₃ represents a hydrogen atom, a halogen atom (e.g., 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 group having a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent.
R ₁₄ represents a hydroxyl group, a halogen atom (e.g., 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 (may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent. When there are a plurality of R ₁₄ , each independently represents the above group such as a hydroxyl group.
Each R ₁₅ independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. Two R ₁₅ may be bonded to each other to form a ring. When two R ₁₅ are bonded to 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, it is preferable that two R ₁₅ are alkylene groups and are bonded to each other to form a ring structure. In addition, the alkyl group, the cycloalkyl group, and the naphthyl group, as well as the ring formed by bonding two R ₁₅ 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. The alkyl group is more preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like.

Next, formula (ZaII) will be described.
In formula (ZaII), R ²⁰⁴ and R ²⁰⁵ each independently represent an aryl group, an alkyl group or a cycloalkyl group.
The aryl group of R ²⁰⁴ and R ²⁰⁵ is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group of R ²⁰⁴ and R ²⁰⁵ may be an aryl group having a heterocycle with an oxygen atom, a nitrogen atom, or a sulfur atom. 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 are preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, a butyl group, or a pentyl group), or a cycloalkyl group having 3 to 10 carbon atoms (e.g., a cyclopentyl group, a cyclohexyl group, or a norbornyl group).

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

Specific examples of the organic cation represented by M ⁺ are shown below, but the present invention is not limited thereto.

The organic anion represented by X 2 ^- in the photodecomposable onium salt compound PG1 is preferably a non-nucleophilic anion (an anion having an extremely low ability to cause a nucleophilic reaction).
Examples of non-nucleophilic anions include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, camphorsulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, aralkyl carboxylate anions, etc.), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

The organic anion is preferably, 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 ^- and R _a1 may be bonded to each other to form a ring.

A ₃₁ ^- represents an anionic group. The anionic group represented by A ₃₁ ^- is not particularly limited, but is preferably, for example, a group selected from the group consisting of groups represented by formulae (BA-1) to (BA-14), and more preferably formulae (BA-1), (BA-2), (BA-3), (BA-4), (BA-5), (BA-6), (BA-10), (BA-12), (BA-13), and (BA-14).

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

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

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

The substituent that the cycloalkyl group in R ^X1 may have is not particularly limited, but is preferably an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms). One or more of the carbon atoms that are ring members of the cycloalkyl group in R ^X1 may be replaced with a carbonyl carbon atom.

The alkyl group in R ^{3 X1} preferably has 1 to 10 carbon atoms, and more preferably has 1 to 5 carbon atoms.
The substituent that the alkyl group in ^R may have is not particularly limited, but is preferably, for example, a cycloalkyl group, a fluorine atom, or a cyano group. Examples of the cycloalkyl group as the substituent are the same as those described when R is ^a cycloalkyl group.
When the alkyl group in R ^X1 has a fluorine atom as the above-mentioned substituent, the above-mentioned alkyl group may be a perfluoroalkyl group.
In addition, the alkyl group in R ^X1 may have one or more -CH ₂ - substituted with a carbonyl group.

The aryl group in R ^X1 is preferably a phenyl group.
The substituent that the aryl ^group in R 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 substituent are the same as those described in the case where R is ^an alkyl group.

In formulae (BA-7) and (BA-11), each R ^X2 independently represents a hydrogen atom or a substituent other than a fluorine atom or a perfluoroalkyl group (for example, an alkyl group not containing a fluorine atom and a cycloalkyl group not containing a fluorine atom). The two R ^X2 in formula (BA-7) may be the same or different.

In formula (BA-8), R ^XF1 represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, among the multiple R ^XF1 , at least one represents a fluorine atom or a perfluoroalkyl group. The two R ^XF1 in formula (BA-8) may be the same or different. The number of carbon atoms of 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 (BA-9), R ^X3 represents a hydrogen atom, a halogen atom, or a monovalent organic group. Examples of the halogen atom represented by R ^X3 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
The monovalent organic group represented by R 1 ^X3 is the same as the monovalent organic group described as R ^{1 X1} .
n1 represents an integer of 0 to 4.
n1 is preferably an integer of 0 to 2, and more preferably 0 or 1. When n1 represents an integer of 2 to 4, multiple R ^{3 X3} may be the same or different.

In formula (BA-10), R ^{2 XF2} represents a fluorine atom or a perfluoroalkyl group.
The perfluoroalkyl group represented by R ^{2 XF2} preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms.

In formula (DA), the number of carbon atoms of the monovalent organic group for R _a1 is not particularly limited, but preferably is 1 to 30 carbon atoms, and more preferably is 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 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and even more preferably an alkyl group having 1 to 10 carbon atoms.
The cycloalkyl group may be monocyclic or polycyclic, and is preferably a cycloalkyl group having 3 to 20 carbon atoms, more preferably a cycloalkyl group having 3 to 15 carbon atoms, and even more preferably a cycloalkyl group having 3 to 10 carbon atoms.
The aryl group may be monocyclic or polycyclic, and is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 15 carbon atoms, and even more preferably an aryl group having 6 to 10 carbon atoms.
The cycloalkyl group may contain heteroatoms as ring members.
The heteroatom is not particularly limited, but examples thereof include a nitrogen atom and an oxygen atom.
Additionally, the cycloalkyl group may contain a carbonyl bond (>C=O) as a ring member atom.
The alkyl group, cycloalkyl group and aryl group may further have a substituent.
In addition, A ^31- and R _a1 may be bonded to each other to form a ring.

The divalent linking group represented by L _a1 is not particularly limited, and examples thereof include an alkylene group, a cycloalkylene group, an aromatic group, -O-, -CO-, -COO-, and a group formed by combining two or more of these.
The alkylene group may be linear or branched and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms.
The cycloalkylene group may be monocyclic or polycyclic and preferably has 3 to 20 carbon atoms, and more preferably has 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, and examples thereof include aromatic rings having 6 to 20 carbon atoms, specifically, a benzene ring, a naphthalene ring, an anthracene ring, a thiophene ring, etc. As the aromatic ring constituting the aromatic group, a benzene ring or a naphthalene ring is preferable, and a benzene ring is more preferable.
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.

As the photodecomposable onium salt compound PG1, it is also preferable to use, for example, the photoacid generators disclosed in paragraphs [0135] to [0171] of WO 2018/193954, paragraphs [0077] to [0116] of WO 2020/066824, and paragraphs [0018] to [0075] and [0334] to [0335] of WO 2017/154345.

The molecular weight of the photodegradable onium salt compound PG1 is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less.

(Photodecomposition type onium salt compound PG2)
Another example of a suitable embodiment of the photodecomposable onium salt compound includes the following compound (I) and compound (II) (hereinafter, "compound (I) and compound (II)" are also referred to as "photodecomposable onium salt compound PG2"). The photodecomposable onium salt compound PG2 has two or more of the above-mentioned salt structural moieties and is a compound that generates a polyvalent organic acid upon exposure to light.
The photodecomposable onium salt compound PG2 will now be described.

<<Compound (I)>>
Compound (I) is a compound having one or more structural moieties X and one or more structural moieties Y, which generates an acid containing a first acidic moiety derived from the structural moiety X and a second acidic moiety derived from the structural moiety Y when irradiated with actinic rays or radiation:
Structural moiety X: a structural moiety consisting of an anionic moiety A ₁ ^- and a cationic moiety M ₁ ⁺ , and which forms a first acidic moiety represented by HA ₁ upon exposure to actinic rays or radiation. Structural moiety Y: a structural moiety consisting of an anionic moiety A ₂ ^- and a cationic moiety M ₂ ⁺ , and which forms a second acidic moiety represented by HA ₂ upon exposure to actinic rays or radiation. However, compound (I) satisfies the following condition I.

Condition I: Compound PI, which is obtained by replacing the cationic moiety M ₁ ⁺ in the structural moiety X and the cationic moiety M ₂ ⁺ in the structural moiety Y in compound (I) with H ⁺ , has an acid dissociation constant a1 derived from the acidic moiety represented by HA ₁ , which is obtained by replacing the cationic moiety M ₁ ⁺ in the structural moiety X with H ⁺ , and an acid dissociation constant a2 derived from the acidic moiety represented by HA ₂ , which is obtained by replacing the cationic moiety M ₂ ⁺ in the structural moiety Y with H ⁺ , and the acid dissociation constant a2 is greater than the acid dissociation constant a1.
The 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 moieties X, the structural moieties X may be the same or different from each other. In addition, the two or more A ₁ ⁻ and the two or more M ₁ ⁺ may be the same or different from each other.
In addition, in compound (I), the A ₁ ^- and A ₂ ^- , and the M ₁ ⁺ and M ₂ ⁺ may be the same or different, but it is preferable that the A ₁ ^- and A ₂ ^- are different.

The anionic moiety A ₁ ^- and the anionic moiety A ₂ ^- are structural moieties containing a negatively charged atom or atomic group, and examples thereof include structural moieties selected from the group consisting of the following formulae (AA-1) to (AA-3) and (BB-1) to (BB-6). In the following formulae (AA-1) to (AA-3) and (BB-1) to (BB-6), * represents a bonding position. Furthermore, 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.

The cationic moiety M ₁ ⁺ and the cationic moiety M ₂ ⁺ are structural moieties containing a positively charged atom or atomic group, and examples thereof include organic cations having a monovalent charge. The organic cation is not particularly limited, but is preferably an organic cation represented by the above formula (ZaI) (cation (ZaI)) or an organic cation represented by the above formula (ZaII) (cation (ZaII)).

<<Compound (II)>>
Compound (II) is a compound having two or more of the above structural moieties X and one or more of the following structural moieties Z, and is a compound that generates an acid containing two or more of the first acidic moieties derived from the structural moiety X and the structural moiety Z when irradiated with actinic rays or radiation.
Structural moiety Z: a non-ionic moiety capable of neutralizing an acid

When irradiated with actinic rays or radiation, the compound (II) can generate a compound PII (acid) having an acidic site represented by HA ₁ in which the cationic site M ₁ ⁺ in the structural site X is replaced with H ⁺ . In other words, the compound PII represents a compound having the acidic site represented by HA ₁ and a structural site Z which is a nonionic site capable of neutralizing an 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 the definitions of A ₁ ^- and M ₁ ⁺ in compound (I) described above, and the preferred embodiments are also the same.
The two or more structural moieties X may be the same or different from each other, and the two or more A ₁ ⁻ and the two or more M ₁ ⁺ may be the same or different from each other.

The nonionic moiety capable of neutralizing an acid in the structural moiety Z is not particularly limited, and is preferably, for example, a moiety containing a functional group having an electron or a group capable of electrostatically interacting with a proton.
Examples of functional groups having a group or electrons capable of electrostatically interacting with a proton include functional groups having a macrocyclic structure such as cyclic polyether, or functional groups having a nitrogen atom having an unshared electron pair that does not contribute to π conjugation. The nitrogen atom having an unshared electron pair 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, azacrown ether structures, primary to tertiary amine structures, pyridine structures, imidazole structures, and pyrazine structures, with primary to tertiary amine structures being preferred.

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

As examples of the photodecomposable onium salt compound PG2, the compounds exemplified in paragraphs [0023] to [0095] of WO 2020/158313 can be cited.

Below is an example of a moiety other than a cation that the photodegradable onium salt compound PG2 may have.

The content of the onium salt compound (A) in the resist composition of the present invention is not particularly limited, but is preferably 0.5 mass% or more, more preferably 1.0 mass% or more, and even more preferably 5.0 mass% or more, based on the total solid content of the resist composition. Also, the content of the onium salt compound (A) is preferably 50.0 mass% or less, and more preferably 40.0 mass% or less, based on the total solid content of the resist composition.
The onium salt compound (A) may be used alone or in combination of two or more. When two or more types are used, the total content is preferably within the above-mentioned preferred content range.

<Polymer (B)>
The composition of the present invention contains a polymer (hereinafter also referred to as polymer (B)) having a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (3). Polymer (B) is a resin whose main chain is decomposed by irradiation with actinic rays or radiation.

(Repeating unit represented by general formula (1))

In general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom. X is preferably a chlorine atom, since this provides a more excellent effect of the present invention.

In formula (1), R ₀ represents a hydrogen atom or an organic group.
The organic group represented by R ₀ is not particularly limited, but is preferably a linear, branched, or cyclic alkyl group.
The alkyl group preferably has 1 to 12 carbon atoms, more preferably has 1 to 6 carbon atoms, and further preferably has 1 to 3 carbon atoms.
The alkyl group may have a substituent. The substituent is not particularly limited, but examples thereof include a halogen atom (preferably a fluorine atom or an iodine atom) and an acidic group having an acidic proton, which will be described later.
R ₀ is preferably a hydrogen atom in that the effects of the present invention are more excellent.

In general formula (1), A ₁ represents an organic group that satisfies the condition that the SP value in the compound represented by A ₁ -O-C(=O)-CH=CH ₂ is 21.00 MPa ^1/2 or more.

In the present invention, the term "SP value (solubility parameters)" means "the value of the solubility parameter". The SP value is derived using the Hansen method. Here, the Hansen method expresses the energy of a substance as three components, namely, a dispersion energy term (δ _D ), a polarization energy term (δ _P ), and a hydrogen bond energy term (δ _H ), and expresses them as vectors in a three-dimensional space.

In the present invention, the SP value is a value calculated by the software Hansen Solubility Parameters in Practice (HSPiP) ver. 4.1.07.
However, if the calculation cannot be performed using the software, the value calculated using the method described in the above paper based on Table 2 in the paper "Hansen Solubility Parameters 50th anniversary conference, preprint PP.1-13, (2017), Hiroshi Yamamoto, Steven Abbott, Charles M. Hansen" published in Yamamoto Preprint Part 1 (https://pirika.com/index-j.html) on the "https://pirika.com/HSP/HSP-J/HSP50/Preprint-Part1%20Yamamoto.pdf" website is used.

The SP value of each component is calculated based on the following formula (spa), where the unit of the SP value is MPa ^1/2 .
[SP value] = (δ _D ² + δ _P ² + δ _H ² ) ^1/2 (spa)

In general formula (1), A ₁ represents an organic group having an SP value of 21.00 MPa ^1/2 or more in the compound represented by A ₁ -O-C(═O)—CH═CH _2. By setting the SP value to 21.00 MPa ^1/2 or more, it is possible to reduce the solubility in a developer in the unexposed areas in the resist film formed from the resist composition of the present invention. From the viewpoint of further reducing the solubility in a developer in the unexposed areas, the lower limit of the SP value is preferably 22.00 MPa ^1/2 or more, and more preferably 23.00 MPa ^1/2 or more.
In addition, the upper limit of the SP value is not particularly limited, but from the viewpoint of the solubility of the coating liquid, it is preferably 35.00 MPa ^1/2 or less. In addition, from the viewpoint of suppressing a decrease in the coatability of the resist composition, the upper limit of the SP value is more preferably 30.00 MPa ^1/2 or less, and even more preferably 25.00 MPa ^1/2 or less.
A ₁ is preferably an organic group that satisfies the condition that the SP value in the compound represented by A ₁ -O-C(=O)-CH=CH ₂ is 21.00 to 25.00 MPa ^1/2 .

The SP value can be adjusted to fall within the above-mentioned range, for example, by selecting _A1 in general formula (1) from a group having a nitrogen-containing aromatic group; a group having an acidic group having an acidic proton; a group having a polar group other than the above; and the like.

The nitrogen-containing aromatic group may be a group represented by the general formula (2a) described below.

Examples of the acidic group having an acidic proton include at least one group selected from the group consisting of a hydroxy group (an alcoholic hydroxy group, a phenolic hydroxy group, etc.), a 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, or a cyano group), an amide group (-NH-COR group; R represents a substituent), an imide group (-CO-NH-COR group), a sulfonylimide group (-SO ₂ -NH-SO ₂ R ^P group; R ^P represents an alkyl group, an aryl group, or a nitrogen-containing aromatic group), a thiol group substituted on a member atom of an aromatic ring, and -C(=O)NHSO ₂ R ^P.

Examples of the polar group include an amide group (-NR ^Q -COR group; R ^Q represents a substituent), an imide group (-CO-NR ^Q -COR group or -N-(COR) ₂ group), a sulfonylimido group (-SO ₂ -NR ^Q -SO ₂ R ^P group), -C(=O)NR ^Q SO ₂ R ^P , an alkoxycarbonyl group, an arylcarbonyl group, a carbonate group, and a cyano group.

The polymer (B) preferably has a repeating unit containing an acidic group having an acidic proton. This acidic group having an acidic proton is an interactive group that can interact with the onium salt compound (A) in the resist composition, so that in the unexposed areas of the resist film formed using the resist composition of the present invention, the onium salt compound (A) and the polymer (B) interact with each other, making the resist film less soluble 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 released, making the resist film more soluble in the developer. In other words, the above action increases the dissolution contrast between the unexposed and exposed areas of the resist film, which is considered to be a superior effect of the present invention.

The repeating unit containing an acidic group having an acidic proton may be any repeating unit constituting the polymer (B). However, it is preferable that the repeating unit is a repeating unit represented by general formula (1), and it is more preferable that _A1 in general formula (1) represents an organic group containing an acidic group having an acidic proton.
As described above, in the polymer in which the main chain decomposition occurs by irradiation with actinic rays or radiation, it is presumed that the main chain decomposes and the ester bond directly connected to the main chain is partially decomposed by irradiation with actinic rays or radiation, causing a decarboxylation reaction. In this case, if A ₁ in the general formula (1) contains an acidic group having an acidic proton, the polarity conversion effect of the polymer due to the decarboxylation reaction becomes larger, and the effect of the present invention is further improved.

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

In formula (2a), Z represents a carbon atom or a nitrogen atom, and AN represents a nitrogen-containing aromatic group.
In formula (2b), R ₁ represents a hydrogen atom or a substituent. R ₂ represents a substituent. R ₁ and R ₂ may be bonded to each other to form a ring.
In formula (2c), _R3 represents an amide group, an imide group, an alkylcarbonyl group, an arylcarbonyl group, a cyano group, a carboxyl group, or a hydroxyl group. n represents an integer of 1 to 5. When n represents an integer of 2 to 5, multiple _R3s may be the same or different.
In formula (2d), L _A represents -C(=O)- or -S(=O) ₂ -. R ₄ represents a hydrogen atom, an alkyl group, an aryl group, or a nitrogen-containing aromatic group. R ₅ represents an alkyl group, an aryl group, or a nitrogen-containing aromatic group.

X and R ₀ in formula (2) have the same meaning as X and R ₀ in formula (1), and preferred examples are also the same.

In formula (2), L represents a single bond or a divalent linking group.
The divalent linking group represented by L is not particularly limited, and examples thereof include an alkylene group, a cycloalkylene group, an arylene group, and a group formed by combining these groups.

The alkylene group may be either a straight chain or a branched chain.
The alkylene group preferably has 1 to 20 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 or 2 carbon atoms.

The cycloalkylene group may be either monocyclic or polycyclic. The number of carbon atoms in the cycloalkylene group is not particularly limited, but is preferably 5 to 15, and more preferably 5 to 10.

The arylene group may be either a monocyclic or polycyclic ring, and is preferably an arylene group having 6 to 20 carbon atoms, more preferably an arylene group having 6 to 15 carbon atoms, and even more preferably an arylene group having 6 to 10 carbon atoms. Of these, the arylene group is preferably a phenylene group or a naphthylene group, and more preferably a phenylene group.

The divalent linking group may have a substituent. The substituent is not particularly limited, and examples thereof include a halogen atom (preferably a fluorine atom or an iodine atom).

L is preferably a single bond or an alkylene group, and more preferably a single bond, a methylene group, or an ethylene group.

In formula (2), A ₁₁ represents a group represented by any one of formulas (2a) to (2d) above.
In formula (2a), Z represents a carbon atom or a nitrogen atom, and AN represents a nitrogen-containing aromatic group.
The aromatic ring in the nitrogen-containing aromatic group represented by AN may be a monocyclic ring or a polycyclic ring. The number of nitrogen atoms contained in the aromatic ring is not particularly limited, but is preferably 1 to 4, and more preferably 1 or 2.
Examples of the aromatic ring include a nitrogen-containing aromatic ring having 3 to 20 carbon atoms. Specific examples include a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, a thiazole ring, an oxazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a benzimidazole ring, and a benzotriazole ring. A monocyclic ring is preferable, and an imidazole ring or a pyridine ring is more preferable.

The nitrogen-containing aromatic group represented by AN may further have a substituent. Preferred examples of the substituent include a hydroxyl group and a cyano group.

In formula (2b), R ₁ represents a hydrogen atom or a substituent. R ₂ represents a substituent.
Substituents represented by R ₁ include alkyl groups, aryl groups, or nitrogen-containing aromatic groups.

The alkyl group represented by R ₁ is preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group.
Examples of the aryl group represented by R ₁ include a phenyl group, a naphthyl group, and an anthryl group, with a phenyl group being particularly preferred.
The nitrogen-containing aromatic group represented by R ₁ includes the group represented by the above general formula (2a).

R ₁ is preferably a hydrogen atom.

Substituents represented by _R2 include alkyl groups, aryl groups, or nitrogen-containing aromatic groups.
Examples of the alkyl group, aryl group, and nitrogen-containing aromatic group represented by _R2 include the same groups as the alkyl group, aryl group, and nitrogen-containing aromatic group represented by _R1 , and preferred examples are also the same.

_R2 preferably represents an alkyl group or an aryl group, and more preferably represents a methyl group or a phenyl group.

_R1 and _R2 may be bonded to each other to form a ring. In particular, it is preferable that _R1 and _R2 are bonded to each other to form a ring having an imide structure.
Specifically, the group represented by general formula (2b) is preferably a group represented by the following general formula (2bc).

In formula (2bc), Z ₁ and Z ₂ each independently represent -C(Rz) ₂ - or -NRz-, where each Rz independently represents a hydrogen atom, an alkyl group, or an aryl group.

The alkyl group and aryl group represented by Rz include the alkyl group and aryl group represented by _R2 above.

Rz contained in _Z1 and Rz contained in _Z2 may be bonded to each other to form a ring. Examples of the ring formed by bonding multiple Rz include an aliphatic hydrocarbon ring such as a cyclopentane ring or a cyclohexane ring, and an aromatic hydrocarbon ring such as a phenyl group.

In formula (2c), _R3 represents an amide group, an imido group, an alkylcarbonyl group, an arylcarbonyl group, a cyano group, a carboxyl group, or a hydroxyl group.

The amide group represented by _R3 includes the group represented by the above general formula (2b).
The imido group represented by _R3 is preferably a group represented by the following formula (M1) or (M2).

In formulae (M1) and (M2), * represents a substitution position.
In formula (M1), R ^M1 represents a hydrogen atom, an alkyl group, or an aryl group.
In formula (M1), R ^M2 represents an alkyl group or an aryl group.
In formula (M2), R ^M3 and R ^M4 each independently represent an alkyl group or an aryl group.

The alkyl group represented by R ^{1 M1} is preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group.
Examples of the aryl group represented by R ^M1 include a phenyl group, a naphthyl group, and an anthryl group, with a phenyl group being particularly preferred.

Examples of the alkyl group and aryl group represented by R ^M2 include the alkyl group and aryl group represented by R ^M1 above, and preferred examples are also the same.
R ^M2 may bond to a ring-membered carbon atom of the phenyl group shown in general formula (2c) to form a ring.

Examples of the alkyl group and aryl group represented by R ^M3 and R ^M4 include the alkyl group and aryl group represented by R ^M1 , and preferred examples are also the same.
R ^M3 and R ^M4 may be bonded to each other to form a ring.

R ^M1 , R ^M2 , R ^M3 and R ^M4 may further have a substituent, preferably a halogen atom.

The alkyl group in the alkylcarbonyl group represented by R ₃ is preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group.
Examples of the aryl group in the arylcarbonyl group represented by _R3 include a phenyl group, a naphthyl group, and an anthryl group, with a phenyl group being particularly preferred.

_R3 preferably represents a carboxyl group or a hydroxyl group.

In general formula (2c), n represents an integer from 1 to 5. n is preferably an integer from 1 to 3, and more preferably 2 or 3.

In formula (2d), R ₄ represents a hydrogen atom, an alkyl group, an aryl group, or a nitrogen-containing aromatic group.
The alkyl group represented by R ₄ is preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group.
Examples of the aryl group represented by _R4 include a phenyl group, a naphthyl group, and an anthryl group, with a phenyl group being particularly preferred.
The nitrogen-containing aromatic group represented by _R4 includes the group represented by the above general formula (2a).
_R4 is preferably a hydrogen atom, an alkyl group, or an aryl group, and more preferably a hydrogen atom, a methyl group, or a phenyl group.

In formula (2d), R ₅ represents an alkyl group, an aryl group, or a nitrogen-containing aromatic group.
Examples of the alkyl group, aryl group and nitrogen-containing aromatic group represented by _R5 include the alkyl group, aryl group and nitrogen-containing aromatic group represented by _R4 .
_R5 is preferably an alkyl group or an aryl group, more preferably a methyl group.

A ₁₁ is preferably a group represented by general formula (2a) or general formula (2c), and more preferably a group represented by general formula (2c).

Specific examples of monomers constituting the repeating unit represented by general formula (1) are listed below, but are not limited to these. In addition, in the following Table 1, the SP value (MPa ^1/2 ) of the compound represented by A ₁ -O-C(═O)-CH═CH ₂ is also listed.

In the polymer (B), the content of the repeating unit represented by the general formula (1) is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 40 mol% or more, based on the total repeating units, and the upper limit is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and particularly preferably 60 mol% or less, based on the total repeating units.
In addition, the repeating unit represented by the general formula (1) may be contained in the polymer (B) alone or in two or more kinds. When two or more kinds are contained, it is preferable that the total content is within the above-mentioned preferable content range.

(Repeating unit represented by general formula (3))

Y represents a hydrogen atom or a methyl group. From the viewpoint of improving the efficiency of decomposition of the main chain, a methyl group is more preferable.

Examples of the aromatic ring in the aromatic ring group represented by _A2 include an aromatic hydrocarbon ring and an aromatic heterocycle. The aromatic ring may be a monocycle or a polycycle.
The aromatic hydrocarbon ring is not particularly limited, and examples thereof include aromatic hydrocarbon rings having 6 to 20 carbon atoms. Specific examples include a benzene ring, a naphthalene ring, an indene ring, an anthracene ring, and an acenaphthylene ring, with a benzene ring or a naphthalene ring being preferred, and a benzene ring being more preferred.
The aromatic heterocycle is not particularly limited, and examples thereof include aromatic heterocycles having 3 to 20 carbon atoms (heteroatoms contained in the ring include, for example, an oxygen atom, a sulfur atom, a nitrogen atom, etc.). Specific examples thereof include a thiophene ring, a furan ring, a pyridine ring, an imidazole ring, a benzimidazole ring, a benzothiazole ring, etc., with the thiophene ring, furan ring, benzimidazole ring, and benzothiazole ring being preferred, and the benzimidazole ring or benzothiazole ring being more preferred.

The aromatic ring in the aromatic ring group represented by _A2 is preferably an aromatic hydrocarbon ring, more preferably a benzene ring.

The aromatic ring group represented by A ₂ may further have a substituent. The substituent of the aromatic ring group is not particularly limited, but examples thereof include a halogen atom, a halogenated alkyl group, an acidic group having an acidic proton, and an electron-donating group.

Halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

Examples of halogenated alkyl groups include linear or branched alkyl groups having 1 to 6 carbon atoms in which any hydrogen atom has been replaced with a halogen atom.

Examples of the acidic group having an acidic proton include the acidic group having an acidic proton in the group having an acidic group having an acidic proton as A ₁ in the above general formula (1).

Preferred examples of the electron-donating group include electron-donating groups having a Hammett's substituent constant σp value of less than 0.

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

The σp value of the electron-donating group is preferably -0.05 or less, and more preferably -0.1 or less. There is no particular lower limit to the σp value of the electron-donating group, but it 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 a methyl group (σp=−0.17) is preferred.
The alkyl group moiety in the alkoxy group serving as the electron-donating group is preferably the above-mentioned alkyl group. The alkoxy group is preferably a methoxy group (σp=−0.27).
The alkyl group moiety in the alkylthio group serving as the electron-donating group is preferably the above-mentioned alkyl group. The alkylthio group is preferably an ethylthio group (σp=−0.1).
The alkyl group moiety in the dialkylamino group as the electron-donating group is preferably the above alkyl group. 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, and more preferably at least one group selected from an alkoxy group, an alkylthio group, a dialkylamino group, and a monoalkylamino group.

_A2 is preferably an aromatic ring group having an electron-donating group. Also, _A2 is preferably an aromatic ring group having an electron-donating group and an acidic group having an acidic proton as a substituent.

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

The repeating unit represented by general formula (3) is preferably a repeating unit represented by the following general formula (4):

Y in general formula (4) has the same meaning as Y in general formula (3), and the preferred examples are also the same.

Examples of EDG in the general formula (4) include the electron-donating groups described as the substituent that _A2 in the general formula (3) may have, and preferred examples are also the same.
_A3 in the general formula (4) may be a halogen atom, a halogenated alkyl group, or an acidic group having an acidic proton, as described above as a substituent that _A2 in the general formula (3) may have, and preferred examples are also the same.
_A3 is a group different from the electron donating group.

m is preferably an integer of 2 to 4, and more preferably 2 or 3.
p is preferably an integer of 0 to 2, and more preferably 0 or 1.

Specific examples of monomers constituting the repeating unit represented by general formula (3) are given below, but the present invention is not limited to these.

In the polymer (B), the content of the repeating unit represented by the general formula (3) is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 40 mol% or more, based on the total repeating units. The upper limit is, for example, preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 80 mol% or less, and particularly preferably 60 mol% or less, based on the total repeating units.
In the polymer (B), the repeating unit represented by the general formula (3) may be contained in one kind alone or in two or more kinds. When two or more kinds are contained, it is preferable that the total content is within the above-mentioned preferable content range.

(Other repeating units)
The polymer (B) may contain repeating units other than the repeating units described above, as long as the effects of the present invention are not impaired.
Specifically, for example, the repeating unit may contain a repeating unit represented by the following general formula (5): Among the repeating units represented by general formula (5), those corresponding to the repeating units represented by the above-mentioned general formula (1) are treated as repeating units represented by general formula (1).

In general formula (5),
_X1 represents a halogen atom.
R ₀₁ represents a hydrogen atom or an organic group.
_L1 represents a single bond or a divalent linking group.
A ₂₁ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a lactone group, or a group containing an onium salt structure.

Examples of the halogen atom represented by X ₁ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the organic group represented by R ₀₁ include the groups described as the organic group represented by R ₀ in the above general formula (1), and preferred examples are also the same.

Examples of the divalent linking group represented by L ₁ include the groups described as the divalent linking group represented by L in the above general formula (1), and preferred examples are also the same.

In formula (5), A ₂₁ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a lactone group, or a group containing an onium salt structure.

The alkyl group represented by A ₂₁ may be a linear or branched alkyl group.
The number of carbon atoms in the alkyl group is not particularly limited, and may be, for example, 1 to 20, more preferably 1 to 10, and further preferably 1 to 6.

The cycloalkyl group represented by A ₂₁ may be either a monocyclic or polycyclic group.
The number of carbon atoms in the cycloalkyl group is not particularly limited, but is, for example, preferably 5 to 15, and more preferably 5 to 10. Examples of the cycloalkyl group include monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group.

The aryl group represented by A ₂₁ may be either a monocyclic or polycyclic ring, and is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 15 carbon atoms, and even more preferably an aryl group having 6 to 10 carbon atoms. Of these, the aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group.

The lactone group represented by A ₂₁ is preferably a 5- to 7-membered lactone group, and more preferably a 5- to 7-membered lactone ring to which another ring structure is condensed in the form of a bicyclo structure or a spiro structure.

The onium salt structure in the group containing an onium salt structure represented by A ₂₁ is a structural moiety having an ion pair of a cation and an anion, and is preferably a structural moiety represented by "X ^n- nM ⁺ " (n represents, for example, an integer of 1 to 3, and preferably represents 1 or 2).
M ⁺ represents a structural moiety containing a positively charged atom or atomic group, and ^Xn- represents a structural moiety containing a negatively charged atom or atomic group. The anion in the onium base is preferably a non-nucleophilic anion (an anion with a significantly low ability to cause a nucleophilic reaction). When the anion in the onium base is a non-nucleophilic anion, it is likely to form a photodecomposition type onium salt structure. Specific examples of the non-nucleophilic anion include the non-nucleophilic anion described above as the generated acid of the photodecomposition type onium salt compound.

The above group represented by A ₂₁ may further have a substituent.

Specific examples of monomers that make up other repeating units are given below, but the present invention is not limited to these.

When polymer (B) contains other repeating units, the content of these repeating units is preferably 30 mol % or less, and more preferably 15 mol % or less, based on the total number of repeating units.

The present invention also relates to an actinic ray-sensitive or radiation-sensitive resin composition comprising (A) an onium salt compound and (B) a polymer having a repeating unit represented by the above general formula (2) and a repeating unit represented by the above general formula (3).
Details of each repeating unit, the preferred range of the content relative to all repeating units of the polymer, and other repeating units that may be contained are as described above.

The polymer (B) can be synthesized according to a conventional method (for example, radical polymerization).
The weight average molecular weight of the polymer (B) is preferably 1,000 to 200,000, more preferably 2,500 to 150,000, and even more preferably 25,000 to 80,000, as calculated in terms of polystyrene by the GPC method. When the weight average molecular weight is within the above range, deterioration of heat resistance and dry etching resistance can be further suppressed. In addition, deterioration of developability and deterioration of film formability due to an increase in viscosity can be further suppressed.
The polydispersity (molecular weight distribution) of the polymer (B) is usually 1.0 to 5.0, preferably 1.0 to 3.0, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0. The smaller the polydispersity, the better the resolution and resist shape.

In the composition of the present invention, the content of the polymer (B) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 65% by mass or more, and particularly preferably 70% by mass or more, based on the total solid content of the composition. The upper limit is preferably 100% by mass or less, and more preferably 95% by mass or less.
The polymer (B) may be used alone or in combination of two or more. When two or more types are used, the total content is preferably within the above-mentioned suitable content range.

<Solvent>
The resist composition of the present invention preferably contains a solvent.
The solvent preferably contains (M1) propylene glycol monoalkyl ether carboxylate and (M2) at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate ester, acetate ester, alkoxypropionate ester, linear ketone, cyclic ketone, lactone, and alkylene carbonate. The solvent may further contain components other than the components (M1) and (M2).

When such a solvent is used in combination with the polymer (B), the coatability of the resist composition is improved and patterns with fewer development defects are easily formed. This is presumably because these solvents have an excellent balance of the solubility, boiling point, and viscosity of the polymer (B), and therefore can suppress unevenness in the thickness of the resist film, which is a film formed from the resist composition, and the occurrence of precipitates during spin coating.

As component (M1), 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 is preferred, with propylene glycol monomethyl ether acetate (PGMEA) being more preferred.

As the component (M2), the following are preferred.
As the propylene glycol monoalkyl ether, propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether (PGEE) are preferred.
The lactate ester is preferably ethyl lactate, butyl lactate, or propyl lactate.
The acetate ester is preferably methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, or 3-methoxybutyl acetate.
Also preferred is butyl butyrate.
As the alkoxypropionate, methyl 3-methoxypropionate (MMP) or ethyl 3-ethoxypropionate (EEP) is preferred.
As the chain ketone, 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, or methyl amyl ketone is preferred.
The cyclic ketone is preferably methylcyclohexanone, isophorone, cyclopentanone, or cyclohexanone.
The lactone is preferably γ-butyrolactone.
As the alkylene carbonate, propylene carbonate is preferred.

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

In addition to the above-mentioned components, the solvent preferably includes an ester-based solvent having 7 or more carbon atoms (preferably 7 to 14, more preferably 7 to 12, and even more preferably 7 to 10) and 2 or less heteroatoms.
As the ester-based solvent having 7 or more carbon atoms and 2 or less heteroatoms, amyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, pentyl propionate, hexyl propionate, butyl propionate, isobutyl isobutyrate, heptyl propionate, or butyl butanoate is preferred, and isoamyl acetate is more preferred.

As the component (M2), those having a flash point (hereinafter also referred to as fp) of 37° C. or more are preferable. As such a component (M2), propylene glycol monomethyl ether (fp: 47° C.), ethyl lactate (fp: 53° C.), ethyl 3-ethoxypropionate (fp: 49° C.), 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.) are preferable. Among these, propylene glycol monoethyl ether, ethyl lactate, pentyl acetate, or cyclohexanone are more preferable, and propylene glycol monoethyl ether or ethyl lactate are even more preferable.
The "flash point" herein refers to the value listed in the reagent catalog of Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Co.

The solvent preferably contains the component (M1). More preferably, the solvent consists essentially of the component (M1) alone, or is a mixed solvent of the component (M1) and other components. In the latter case, the solvent further preferably contains both the component (M1) and the component (M2).
The mass ratio (M1/M2) of the component (M1) to the component (M2) is preferably in the range of "100/0" to "15/85", more preferably in the range of "100/0" to "40/60", and even more preferably in the range of "100/0" to "60/40". In other words, the solvent is preferably composed of only the component (M1) or contains both the component (M1) and the component (M2), and the mass ratio thereof is as follows. In other words, in the latter case, the mass ratio of the component (M1) to the component (M2) is preferably 15/85 or more, more preferably 40/60 or more, and even more preferably 60/40 or more. By adopting such a configuration, it is possible to further reduce the number of development defects.

When the solvent contains both component (M1) and component (M2), the mass ratio of component (M1) to component (M2) can be, for example, 99/1 or less.

If the solvent further contains components other than components (M1) and (M2), the content of the components other than components (M1) and (M2) is preferably 5 to 30 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 solids concentration is 0.5 to 30% by mass, and more preferably 1 to 20% by mass, in order to provide better coatability.

<Hydrophobic resin>
The resist composition of the present invention may further contain a hydrophobic resin different from the polymer (B).
The hydrophobic resin is preferably designed to be unevenly distributed on the surface of the resist film, but unlike a surfactant, it does not necessarily have to have a hydrophilic group in the molecule, and does not necessarily have to contribute to uniform mixing of polar and non-polar substances.
The effects of adding a hydrophobic resin include control of the static and dynamic contact angles of the resist film surface with respect to the developer, and suppression of outgassing.

From the viewpoint of uneven distribution on the surface layer of the film, the hydrophobic resin preferably has at least one of fluorine atoms, silicon atoms, and _CH3 partial structures contained in the side chain portion of the resin, more preferably has at least two of them. The hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted on the side chain.
Examples of hydrophobic resins include the compounds described in paragraphs [0275] to [0279] of WO 2020/004306.

When the resist composition of the present invention contains a hydrophobic resin, the content of the hydrophobic resin is preferably from 0.01 to 20.0 mass %, and more preferably from 0.1 to 15.0 mass %, based on the total solid content of the resist composition.
The hydrophobic resin may be used alone or in combination of two or more. When two or more types are used, the total content is preferably within the above-mentioned preferred content range.

<Surfactant>
The resist composition may contain a surfactant, which can provide a pattern with better adhesion and fewer development defects.
The surfactant is preferably a fluorine-based and/or silicon-based surfactant.
Examples of fluorine-based and/or silicone-based surfactants include the surfactants disclosed in paragraphs [0218] and [0219] of WO 2018/193954.
When the resist composition contains a surfactant, the content of the surfactant is preferably from 0.0001 to 2 mass %, and more preferably from 0.0005 to 1 mass %, based on the total solid content of the resist composition.
The surfactant may be used alone or in combination of two or more. When two or more surfactants are used, the total content is preferably within the above-mentioned preferred content range.

[Resist film and pattern forming method]
The present invention also relates to a resist film formed using the above actinic ray-sensitive or radiation-sensitive resin composition.
The present invention also relates to a pattern forming method, comprising the steps of forming a film using the actinic ray-sensitive or radiation-sensitive resin composition, exposing the film to light, and developing the exposed film using a developer.

The procedure for forming a pattern using the resist composition is not particularly limited, but it is preferable for the method to include the following steps.
Step 1: Forming a resist film on a substrate using an actinic ray-sensitive or radiation-sensitive resin composition; Step 2: Exposing the resist film; Step 3: Developing the exposed resist film using a developer containing an organic solvent. The procedure of each of the above steps will be described in detail below.

<Step 1: Resist film forming step>
Step 1 is a step of forming a resist film on a substrate using an actinic ray-sensitive or radiation-sensitive resin composition.
The resist composition is as defined above.

An example of a method for forming a resist film on a substrate using a resist composition is a method in which the resist composition is applied onto a substrate.
It is preferable to filter the resist composition before coating as necessary. 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. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

The resist composition can be applied onto a substrate (e.g., silicon, silicon dioxide-coated) such as those used in the manufacture of integrated circuit elements by a suitable application method such as a spinner or coater. The application method is preferably spin coating using a spinner. The rotation speed when spin coating using a spinner is preferably 1000 to 3000 rpm (rotations per minute).
After coating the resist composition, the substrate may be dried to form a resist film. If necessary, various undercoats (inorganic films, organic films, anti-reflective films) may be formed under the resist film.

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

The thickness of the resist film is not particularly limited, but is preferably 10 to 120 nm, since it allows for the formation of fine patterns with higher accuracy. In particular, when EUV exposure and EB exposure are used, the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. Furthermore, when ArF immersion exposure is used, the thickness of the resist film is more preferably 10 to 120 nm, and even more preferably 15 to 90 nm.

A top coat may be formed on the resist film using a top coat composition.
It is preferable that 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. For example, a top coat can be formed based on the description in paragraphs [0072] to [0082] of JP2014-059543A.
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.
The top coat also preferably 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 to light.
The exposure method may be a method in which the formed resist film is irradiated with actinic rays or radiation through a predetermined mask.
Examples of actinic rays or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams, and preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less, and particularly preferably 1 to 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 carry out a post-exposure heat treatment (also called post-exposure bake) before development, which promotes the reaction of the exposed area and improves the sensitivity and pattern shape.
The heating temperature is preferably from 80 to 150°C, more preferably from 80 to 140°C, and even more preferably from 80 to 130°C.
The heating time is preferably from 10 to 1,000 seconds, more preferably from 10 to 180 seconds, and even more preferably from 30 to 120 seconds.
Heating can be carried out by a 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 with a developer to form a pattern.
The developer may be an alkaline developer or a developer containing an organic solvent (hereinafter also referred to as an organic developer), but is preferably an organic developer.

Examples of the developing method include a method of immersing a substrate in a tank filled with a developing solution for a certain period of time (dip method), a method of piling up the developing solution on the substrate surface by surface tension and leaving it still for a certain period of time to develop (paddle method), a method of spraying the developing solution on the substrate surface (spray method), and a method of continuously discharging the developing solution while scanning a developing solution discharge nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispense method).
After the development step, a step of stopping the development while replacing the solvent with another solvent may be carried out.
The development time is not particularly limited as long as the resin in the unexposed area is sufficiently dissolved, and is preferably from 10 to 300 seconds, more preferably from 20 to 120 seconds.
The temperature of the developer is preferably from 0 to 50°C, and more preferably from 15 to 35°C.

The alkaline developer is preferably an aqueous alkaline solution containing an alkali. There are no particular limitations on the type of the aqueous alkaline solution, but examples include an aqueous alkaline solution containing a quaternary ammonium salt such as tetramethylammonium hydroxide, an inorganic alkali, a primary amine, a secondary amine, a tertiary amine, an alcohol amine, or a cyclic amine. Of these, the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt such as tetramethylammonium hydroxide (TMAH). Appropriate amounts of alcohols, surfactants, etc. may be added to the alkaline developer. The alkaline concentration of the alkaline developer is usually preferably 0.1 to 20% by mass. The pH of the alkaline developer is usually preferably 10.0 to 15.0.

The organic developer preferably contains at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents.

The above-mentioned solvents may be mixed in combination, or may be mixed with a solvent other than the above or with 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, still more preferably 90% by mass or more and 100% by mass or less, and particularly preferably 95% by mass or more and 100% by mass or less, based on the total amount of the developer.

<Other steps>
The above pattern forming method preferably includes, after step 3, a step of washing with a rinsing liquid.

The rinse liquid used in the rinse step following the step of developing with an alkaline developer is, for example, pure water, to which an appropriate amount of a surfactant may be added.
A suitable amount of a surfactant may be added to the rinse solution.

The rinse liquid used in the rinse step following the development step using an organic developer is not particularly limited as long as it does not dissolve the pattern, and a solution containing a general organic solvent can be used. It is preferable to use a rinse liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

The method of the rinsing step is not particularly limited, and examples thereof include a method of continuously discharging a rinsing liquid onto a substrate rotating at a constant speed (spin coating method), a method of immersing a substrate in a tank filled with the rinsing liquid for a certain period of time (dip method), and a method of spraying the rinsing liquid onto the substrate surface (spray method).
The pattern forming method of the present invention may also include a heating step (Post Bake) after the rinsing step. This step removes the developer and rinsing solution remaining between the patterns and inside the pattern due to baking. This step also has the effect of annealing the resist pattern and improving the surface roughness of the pattern. The heating step after the rinsing step is usually performed at 40 to 250°C (preferably 90 to 200°C) for usually 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

Furthermore, the formed pattern may be used as a mask to perform an etching process on the substrate. That is, the pattern formed in step 3 may be used as a mask to process the substrate (or the underlayer film and the substrate) to form a pattern on the substrate.
Although the method for processing the substrate (or the underlayer film and the substrate) is not particularly limited, a method is preferred in which the substrate (or the underlayer film and the substrate) is dry-etched using the pattern formed in step 3 as a mask to form a pattern on the substrate. The dry etching is preferably oxygen plasma etching.

The resist composition and various materials used in the pattern formation method of the present invention (e.g., solvent, developer, rinse, anti-reflective film forming composition, top coat forming composition, etc.) preferably do not contain impurities such as metals. The content of impurities contained in these materials is preferably 1 mass ppm (parts per million) or less, more preferably 10 mass ppb (parts per billion) or less, even more preferably 100 mass ppt (parts per trillion) 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, and Zn.

An example of a method for removing impurities such as metals from various materials is filtration using a filter. Details of filtration using a filter are described in paragraph [0321] of WO 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 the raw materials that make up the various materials, filtering the raw materials that make up the various materials, and performing distillation under conditions that minimize contamination as much as possible, such as lining the inside of the equipment with Teflon (registered trademark).

In addition to filtration, impurities may be removed using an adsorbent, or a combination of filtration and an adsorbent may be used. As the adsorbent, known adsorbents can be used, for example, 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 the incorporation of metal impurities during the manufacturing process. Whether or not metal impurities have been sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of metal components contained in the cleaning solution used to clean the manufacturing equipment. The content of metal components contained in the cleaning solution after use is preferably 100 ppt by mass or less, more preferably 10 ppt by mass or less, and even more preferably 1 ppt by mass or less.

Furthermore, the resist composition may contain water as an impurity. When water is contained as an impurity, the smaller the water content, the more preferable, but the resist composition may contain 1 to 30,000 ppm by mass of water as a whole.
Furthermore, the resist composition may contain a residual monomer as an impurity (for example, a monomer derived from the raw material monomer used in the synthesis of the polymer (B)). When the resist composition contains a residual monomer as an impurity, the smaller the content of the residual monomer, the more preferable, but the resist composition may contain the residual monomer in an amount of 1 to 30,000 ppm by mass relative to the total solid content of the resist composition.

An organic processing liquid such as a rinse liquid may contain a conductive compound to prevent breakdown of chemical liquid piping and various parts (filters, O-rings, tubes, etc.) due to static electricity buildup and subsequent static electricity discharge. The conductive compound is not particularly limited, but an example thereof is methanol. The amount added is not particularly limited, but from the viewpoint of maintaining favorable development characteristics or rinsing characteristics, it is preferably 10% by mass or less, and more preferably 5% by mass or less.
The chemical liquid piping may be made of, for example, stainless steel (SUS), or various piping coated with antistatic polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.). Similarly, the filter and O-ring may be made of antistatic polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.).

[Electronic device manufacturing method]
The present invention also relates to a method for manufacturing an electronic device, which includes the above-mentioned pattern formation method, and an electronic device manufactured by this manufacturing method.
The electronic device of the present invention is suitably mounted in electric and electronic equipment (such as home appliances, OA (Office Automation), media-related equipment, optical equipment, and communication equipment).

The present invention will be described in more detail below based on examples. The materials, amounts used, ratios, processing contents, 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 interpreted as being limited by the examples shown below.

[Various components of actinic ray- or radiation-sensitive resin composition]
[Polymer (B)]
The polymers shown in Table 3 (B-1 to B-20 and RB-1 to RB-6) are shown below.
B-6 was synthesized by the synthesis method (Synthesis Example 1) described below. B-1 to B-5, B-7 to B-20, and RB-1 to RB-6 were synthesized according to Synthesis Example 1 or by known methods. Polymers RB-1 to RB-6 are comparative polymers.

Table 2 shows the compositions of polymers B-1 to B-20 and RB-1 to RB-6 (types of raw material monomers, composition ratios of repeating units (mol %), weight average molecular weights (Mw), and dispersity (Mw/Mn)).
The weight average molecular weight (Mw) and dispersity (Mw/Mn) of polymers B-1 to B-20 and RB-1 to RB-6 were measured by GPC (carrier: tetrahydrofuran (THF)) (polystyrene equivalent). The composition ratio (mol % ratio) of the polymers was measured by ¹³ C-NMR (Nuclear Magnetic Resonance).

Table 2 also shows the SP value (unit: MPa 1/2 ) of the compound represented by A ₁ -O-C(═O)-CH═CH ₂ for the repeating unit represented by general formula (1) (shown as repeating unit ¹ in Table 2).
Although H-3 as a raw material monomer does not correspond to the repeating unit represented by general formula (1), it shows the SP value (unit: MPa ^1/2 ) of a compound represented by H ₂ N-C(=)OCH ₂ -O-C(=O)-CH=CH ₂ .
Furthermore, O-1, O-3, O-6, and O-7 as raw material monomers do not correspond to the repeating unit represented by general formula (1), but each of them indicates the SP value (unit: MPa 1/2 ) of a compound in which a portion other than *-OC(=O)-C(=CH ₂ )Cl is bonded to *-OC( ⁼ O)-CH=CH ₂ from the above monomers.
The SP value was measured by the above-mentioned method, and the SP value was calculated by the above-mentioned software Hansen Solubility Parameters in Practice (HSPiP) ver. 4.1.07.

In the polymers B-1 to B-20 and RB-1 to RB-6 in Table 2 above, the respective raw material monomers are as follows.
In polymers B-1 to B-20, the raw material monomer for repeating unit 1 in Table 1 is a raw material monomer for the repeating unit represented by general formula (1) selected from monomers M-1 to M-14 below. The raw material monomer for repeating unit 2 in Table 1 is a raw material monomer for the repeating unit represented by general formula (2) selected from monomers N-1 to N-8 below.
In N-7 and N-8, the σp value of each group shown as an electron-donating group was all less than 0.

Under a nitrogen stream, 0.99 g of cyclohexanone was placed in a three-neck flask and heated to 85 ° C. Then, into the three-neck flask, 8.33 g of monomer M-7a, 4.13 g of monomer N-7, 0.32 g of triethylamine, 0.23 g of a 20% by mass solution of polymerization initiator V-601 (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), and a mixed solution of 3.47 g of cyclohexanone were dropped over 4 hours, and after the dropwise addition, the reaction was allowed to proceed for another 2 hours at 85 ° C. After the reaction was completed, the reaction solution was allowed to cool. Next, the reaction solution after cooling was dropped into 300 g of stirred methanol, and the powder precipitated by the dropwise addition was filtered and dried to obtain resin B'-6.
Next, Resin B'-6 (total amount), 12.0 g of cyclohexanone, and 12.0 g of methanol were placed in a three-neck flask and stirred under a nitrogen stream. Next, 2 g of hydrochloric acid (1N) was added to the three-neck flask and reacted at 40°C for 16 hours.
After the reaction was completed, the reaction solution was allowed to cool. The reaction solution after cooling was then extracted with 200 g of ethyl acetate and 70 g of water, and further washed with water to remove hydrochloric acid. The obtained ethyl acetate solution was concentrated and dissolved in 20 g of methanol, and the obtained solution was dropped into 200 g of water, and the powder precipitated by the dropwise addition was collected by filtration and dried to obtain resin B-6.

The composition ratio (molar ratio) of the repeating units of the resin B-6 determined by ¹³ C-NMR was 54/46 (repeating units derived from monomer M-7/repeating units derived from monomer N-7). The weight average molecular weight of the obtained resin B-6 measured by GPC was 40,000, and the polydispersity (Mw/Mn) was 1.79. The amount of the remaining monomer was measured, and was found to be 0.1% by mass or less relative to the amount of the resin B-6.

[Onium Salt Compound (A)]
The structures of the onium salt compounds (A-1 to A-4) shown in Table 3 are shown below. All of the onium salt compounds (A-1 to A-4) are photodecomposable onium salt compounds.

〔solvent〕
The solvents shown in Table 3 are as follows:
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- or radiation-sensitive resin composition]
The components other than the solvent shown in Table 3 were mixed so that the solid content concentration was 1.3 mass %. The resulting mixture was then filtered through a polyethylene filter having a pore size of 0.03 μm to prepare a resist composition. Here, the solid content refers to all components other than the solvent.
The contents (% by mass) of the polymer and onium salt compound in Table 3 indicate the contents in the total solid content of the composition.
The resist composition thus obtained was used in the examples and comparative examples.

[Pattern formation and evaluation]
[Pattern formation by EUV exposure and evaluation: Examples 1 to 23, Comparative Examples 1 to 6]
<Pattern formation>
An underlayer 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 an underlayer film with a thickness of 20 nm. A resist composition shown in Table 3 was applied thereon and baked at 100° C. for 60 seconds to form a resist film with a thickness of 30 nm. In this way, a silicon wafer having a resist film was formed.
The silicon wafer having the resist film obtained by the above procedure was subjected to pattern irradiation using an EUV exposure device (Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36, manufactured by Exitech). As a reticle, a mask with a line:space ratio of 1:1 was used.
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 dose required to resolve a 1:1 line-and-space resist pattern with the smallest line width (limiting resolution: line width 16-12 nm in this example, line width 21-17 nm in this comparative example) was defined as the sensitivity (Eop). The smaller this value, the higher the sensitivity.

<Resolution>
The limiting resolving power (the minimum line width at which a line and a space (line:space=1:1) are resolved separately) at the exposure dose showing the above sensitivity (Eop) was taken as the resolution (nm). The smaller this value, the higher the resolution.

The results shown in Table 3 clearly show that the resist composition of the embodiment has excellent sensitivity and resolution in the formation of ultrafine patterns.

[Pattern formation by EB exposure and evaluation: Examples 1A to 23A]
When a resist film was formed using each of the resist compositions of the Examples and then exposed to an electron beam to form a pattern, the results showed the same tendency as when the pattern was formed by EUV exposure.

According to the present invention, there can be provided an actinic ray-sensitive or radiation-sensitive resin composition which is excellent in sensitivity and resolution in the formation of ultrafine patterns (for example, a line-and-space pattern having a line width of 20 nm or less, or a hole pattern having a hole diameter of 20 nm or less).
Furthermore, according to the present invention, there can be provided a resist film, a pattern forming method, and a method for producing an electronic device, each of which uses the actinic ray-sensitive or radiation-sensitive resin composition.

Although the present 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 therein without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application (Patent Application No. 2022-198240) filed on December 12, 2022, the contents of which are incorporated herein by reference.

Claims

(A) an onium salt compound, and
(B) An actinic ray-sensitive or radiation-sensitive resin composition comprising a polymer having a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (3):

In the general formula (1),
X represents a chlorine atom, a bromine atom, or an iodine atom.
A 1 represents an organic group that satisfies the condition that the SP value in the compound represented by A 1 -O-C(=O)-CH=CH 2 is 21.00 MPa 1/2 or more.
R 0 represents a hydrogen atom or an organic group.

In the general formula (3),
Y represents a hydrogen atom or a methyl group.
A2 represents an aromatic ring group.
The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein A 1 in the general formula (1) is an organic group that satisfies the condition that the SP value in the compound represented by A 1 -O-C(═O)-CH═CH 2 is 21.00 to 25.00 MPa 1/2 .
The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, wherein the polymer has a repeating unit containing an acidic group having an acidic proton.
4. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 3, wherein the repeating unit containing an acidic group having an acidic proton is a repeating unit represented by general formula (1), and A 1 in general formula (1) represents an organic group containing the acidic group having an acidic proton.
The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein A 2 in the general formula (3) is an aromatic ring group having an electron-donating group.
The actinic ray-sensitive or radiation-sensitive resin composition according to claim 5 , wherein the repeating unit represented by the general formula (3) is a repeating unit represented by the following general formula (4):

In general formula (4),
Y represents a hydrogen atom or a methyl group.
EDG represents an electron donating group.
A3 represents a substituent.
m represents an integer of 1 to 5.
p represents an integer of 0 to 5, provided that 1≦m+p≦5 is satisfied.
(A) an onium salt compound, and
(B) An actinic ray-sensitive or radiation-sensitive resin composition comprising a polymer having a repeating unit represented by the following general formula (2) and a repeating unit represented by the following general formula (3):

In the general formula (2),
X represents a chlorine atom, a bromine atom, or an iodine atom.
R 0 represents a hydrogen atom or an organic group.
L represents a single bond or a divalent linking group.
A 11 represents a group represented by any one of the following general formulas (2a) to (2d).

In general formula (2a),
Z represents a carbon atom or a nitrogen atom.
AN represents a nitrogen-containing aromatic group.
In general formula (2b),
R 1 represents a hydrogen atom or a substituent.
R2 represents a substituent.
R1 and R2 may be bonded to each other to form a ring.
In general formula (2c),
R3 represents an amide group, an imido group, an alkylcarbonyl group, an arylcarbonyl group, a cyano group, a carboxyl group, or a hydroxyl group.
n represents an integer of 1 to 5.
When n is an integer of 2 to 5, multiple R 3 's may be the same or different.
In general formula (2d),
L A represents -C(=O)- or -S(=O) 2 -.
R4 represents a hydrogen atom, an alkyl group, an aryl group, or a nitrogen-containing aromatic group.
R5 represents an alkyl group, an aryl group, or a nitrogen-containing aromatic group.

In the general formula (3),
Y represents a hydrogen atom or a methyl group.
A2 represents an aromatic ring group.
A resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1 to 7.
A step of forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1 to 7;
exposing the resist film to light;
and developing the exposed resist film with a developer.
A method for manufacturing an electronic device, comprising the pattern formation method according to claim 9.