TW202419480A - Photosensitive or radiation-sensitive resin composition, photoresist film, pattern forming method, method for manufacturing electronic device and polymer - Google Patents

Abstract

The present invention provides an actinic ray or radiation-sensitive resin composition, a photoresist film, a pattern forming method, a method for manufacturing an electronic device including the pattern forming method, and a polymer useful for the actinic ray or radiation-sensitive resin composition. The actinic ray or radiation-sensitive resin composition comprises (A) an onium salt compound and (B) a polymer. The polymer has repeating units, and the main chain is decomposed by irradiation with actinic rays or radiation. The repeating units contain acidic groups having acidic protons. The polymer has repeating units represented by a specific general formula.

Description

Photosensitive or radiation-sensitive resin composition, photoresist film, pattern forming method, method for manufacturing electronic device, and polymer

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

Since the development of photoresists for KrF excimer lasers (248nm), a pattern formation method using chemical amplification has been adopted to compensate for the decrease in sensitivity caused by light absorption. For example, in the positive chemical amplification method, first, the photoacid generator contained in the exposure part is decomposed by light irradiation to generate acid. Then, in the post-exposure baking (PEB: Post Exposure Bake) process, the alkali-insoluble groups of the resin contained in the photosensitive or radiation-sensitive resin composition are changed to alkali-soluble groups by the catalytic action of the generated acid, thereby changing the solubility in the developer. After that, development is performed using, for example, an alkaline aqueous solution. In this way, the exposure part is removed to obtain the desired pattern. In order to miniaturize semiconductor devices, the exposure light source has been shortened to a shorter wavelength and the projection lens has been made to have a higher numerical aperture (high NA). Currently, an exposure machine using an ArF excimer laser with a wavelength of 193nm as a light source has been developed. In addition, recently, pattern formation methods using extreme ultraviolet light (EUV light: Extreme Ultraviolet) and electron beam (EB: Electron Beam) as light sources are being studied. Under these circumstances, various structures have been proposed as photosensitive or radiation-sensitive resin compositions.

For example, Patent Document 1 describes a polymer having a repeating unit containing a phenolic hydroxyl group, and the main chain can be cut by irradiation with an electron beam, resulting in a decrease in molecular weight. [Prior Art Document] [Patent Document]

Patent document 1: Japanese Patent Application Publication No. 2020-16699

[The problem that the invention wants to solve]

The inventors of the present invention prepared and studied an actinic radiation or radiation-sensitive resin composition containing a specified polymer with reference to Patent Document 1, and found that the sensitivity did not meet the level required recently, and there was room for further improvement. In addition, it was found that the LWR (line width roughness) performance of the pattern formed by the above composition, especially when forming an ultrafine pattern, was poor, and there was room for further improvement.

Therefore, the subject of the present invention is to provide an actinic radiation-sensitive or radiation-sensitive resin composition, which can form a pattern with excellent sensitivity and excellent LWR performance in ultrafine pattern formation (for example, a line and space pattern with a line width of less than 15nm or a hole pattern with a hole diameter of less than 15nm). In addition, the subject of the present invention is to provide a photoresist film, a pattern forming method, and a method for manufacturing an electronic device using the above-mentioned actinic radiation-sensitive or radiation-sensitive resin composition. In addition, the subject of the present invention is to provide a polymer useful for the above-mentioned actinic radiation-sensitive or radiation-sensitive resin composition. [Means for solving the problem]

The inventors of the present invention have found that the above-mentioned problem can be solved by the following structure.

[1] An actinic radiation-sensitive or radiation-sensitive resin composition comprising: (A) an onium salt compound; and (B) a polymer, wherein the polymer has a repeating unit and the main chain is decomposed by irradiation with actinic radiation or radiation, wherein the repeating unit contains an acidic group having an acidic proton, wherein the polymer has a repeating unit represented by the following general formula (1), wherein the acidic group is selected from a phenolic hydroxyl group, a carboxyl ^group , _-SO2NHRN ( ^RN represents a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group), an amide group, a carbonylimide group, a sulfonimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O) _NHSO2RP ⁽ R ^P represents at least one group selected from the group consisting of an alkyl group or an aryl group.

[Chemical formula 1]

In the general formula (1), Y represents a hydrogen atom or a alkyl group. ^A2 represents an aromatic ring group having an electron donating group. The electron donating group is not equivalent to the acidic group.

[2] The photosensitive or radiation-sensitive resin composition as described in [1], wherein the polymer has a repeating unit represented by the following general formula (2).

[Chemical formula 2]

In the general formula (2), X represents a halogen atom. ^L1 represents -O- or ^-NR1- . ^R1 represents a hydrogen atom or an organic group. ^A1 represents a hydrogen atom or an organic group. ^R0 represents a hydrogen atom or an organic group. ^R0 may be linked to ^A1 or ^R1 to form a ring.

[3] The photosensitive or radiation-sensitive resin composition as described in [1] or [2], wherein the polymer comprises a repeating unit represented by the following general formula (1-2) and a repeating unit represented by the following general formula (2-2).

[Chemical formula 3]

In the general formula (1-2), Y represents a hydrogen atom or a alkyl group. ^R2 represents the above-mentioned acidic group having an acidic proton. When there are multiple ^R2s , the multiple ^R2s may be the same or different. ^R3 represents an electron donating group. When there are multiple ^R3s , the multiple ^R3s may be the same or different. Wherein, the above-mentioned electron donating group is not equivalent to the above-mentioned acidic group. ^L2 represents a single bond or a divalent linking group. m represents an integer of 1 to 4. n represents an integer of 1 to 4. Wherein, 1≤m+n≤5 is satisfied.

[Chemical formula 4]

In the general formula (2-2), X represents a halogen atom. ^A1 represents a hydrogen atom or an organic group. ^R0 represents a hydrogen atom or an organic group. ^R0 may be linked to ^A1 to form a ring.

[4] The photosensitive or radiation-sensitive resin composition as described in any one of [1] to [3], wherein the electron-donating group is at least one group selected from alkyl, alkoxy, alkylthio, dialkylamine, and monoalkylamine.

[5] The photosensitive or radiation-sensitive resin composition as described in any one of [1] to [4], wherein the content of the onium salt compound is 0.1 to 20% by weight relative to the total solid content of the photosensitive or radiation-sensitive resin composition.

[6] A polymer having a repeating unit, wherein the repeating unit contains an acidic group having an acidic proton, wherein the polymer comprises a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2), wherein the acidic group represents at least one group selected from the group consisting of a phenolic hydroxyl group, a carboxyl ^group , _-SO2NHRN ( ^RN 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, a carbonylimide group, a sulfonimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C ^{(=O)NHSO2RP (RP} _represents ^an alkyl group or an aryl group).

[Chemical formula 5]

In the general formula (1), Y represents a hydrogen atom or a alkyl group. ^A2 represents an aromatic ring group having an electron donating group. The electron donating group is not equivalent to the acidic group.

[Chemical formula 6]

In the general formula (2), X represents a halogen atom. ^L1 represents -O- or ^-NR1- . ^R1 represents a hydrogen atom or an organic group. ^A1 represents a hydrogen atom or an organic group. ^R0 represents a hydrogen atom or an organic group. ^R0 may be linked to ^A1 or ^R1 to form a ring.

[7] The polymer described in [6] contains a repeating unit represented by the following general formula (1-2) and a repeating unit represented by the following general formula (2-2).

[Chemical formula 7]

In the general formula (1-2), Y represents a hydrogen atom or a alkyl group. ^R2 represents the above-mentioned acidic group having an acidic proton. When there are multiple ^R2s , the multiple ^R2s may be the same or different. ^R3 represents an electron donating group. When there are multiple ^R3s , the multiple ^R3s may be the same or different. Wherein, the above-mentioned electron donating group is not equivalent to the above-mentioned acidic group. ^L2 represents a single bond or a divalent linking group. m represents an integer of 1 to 4. n represents an integer of 1 to 4. Wherein, 1≤m+n≤5 is satisfied.

[Chemical formula 8]

In the general formula (2-2), X represents a halogen atom. ^A1 represents a hydrogen atom or an organic group. ^R0 represents a hydrogen atom or an organic group. ^R0 may be linked to ^A1 to form a ring.

[8] An actinic radiation-sensitive or radiation-sensitive resin composition comprising: (A) an onium salt compound; and (B1) a polymer, the polymer having repeating units containing at least one group selected from the group consisting of a phenolic hydroxyl group, a carboxyl ^group , _-SO2NHRN ( ^RN represents a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group), an amide group, a carbonylimide group, a sulfonimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O) _NHSO2RP ( ^RP represents an alkyl group or an aryl group), wherein ^the polymer has repeating units represented by the following general formula (1) and repeating units represented by the following general formula (2).

[Chemical formula 9]

In the general formula (1), Y represents a hydrogen atom or a alkyl group. ^A2 represents an aromatic ring group having an electron-donating group. The electron-donating group is not equivalent to the at least one group mentioned above.

[Chemical formula 10]

In the general formula (2), X represents a halogen atom. ^L1 represents -O- or ^-NR1- . ^R1 represents a hydrogen atom or an organic group. ^A1 represents a hydrogen atom or an organic group. ^R0 represents a hydrogen atom or an organic group. ^R0 may be linked to ^A1 or ^R1 to form a ring.

[9] A photoresist film formed using a photosensitive or radiation-sensitive resin composition as described in any one of [1] to [5] and [8]. [10] A pattern forming method comprising: a process of forming a photoresist film on a substrate using a photosensitive or radiation-sensitive resin composition as described in any one of [1] to [5] and [8]; a process of exposing the photoresist film; and a process of developing the exposed photoresist film using a developer. [11] A method for manufacturing an electronic device, comprising the pattern forming method as described in [10]. [Effect of the invention]

According to the present invention, a photosensitive or radiation-sensitive resin composition can be provided, which can form a pattern with excellent sensitivity and excellent LWR performance in ultrafine pattern formation (for example, a line and space pattern with a line width of less than 15nm or a hole pattern with a hole diameter of less than 15nm). In addition, according to the present invention, a photoresist film, a pattern forming method, and a method for manufacturing an electronic device using the above-mentioned photosensitive or radiation-sensitive resin composition can be provided. In addition, according to the present invention, a polymer useful for the above-mentioned photosensitive or radiation-sensitive resin can be provided.

The present invention is described in detail below. The description of the constituent elements described below is sometimes based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. For the notation of the groups (atomic groups) in this specification, as long as it is not contrary to the main purpose of the present invention, the notation notating substitution and unsubstituted includes both groups without substituents and groups with substituents. For example, "alkyl" includes not only alkyl groups without substituents (unsubstituted alkyl groups) but also alkyl groups with substituents (substituted alkyl groups). In addition, the so-called "organic group" in this specification refers to a group containing at least one carbon atom. Unless otherwise specified, the substituent is preferably a monovalent substituent. The term "actinic ray" or "radiation" in this specification refers to, for example, mercury lamp line spectrum, far ultraviolet represented by excimer laser, extreme ultraviolet (EUV), X-ray, and electron beam (EB). "Light" in this specification refers to actinic ray or radiation. Unless otherwise specified, "exposure" in this specification includes not only exposure using mercury lamp line spectrum, far ultraviolet represented by excimer laser, extreme ultraviolet, X-ray, and EUV light, but also drawing using particle beams such as electron beams and ion beams. In this specification, "~" is used to include the numerical values before and after it as lower and upper limits. The bonding direction of the divalent groups described in this specification is not limited unless otherwise specified. For example, in the compound represented by the formula "X-Y-Z", when Y is -COO-, Y can be -CO-O- or -O-CO-. In addition, the above compound can be either "X-CO-O-Z" or "X-O-CO-Z".

In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersion degree (also called molecular weight distribution) (Mw/Mn) of the resin are defined as polystyrene conversion values obtained by GPC (Gel Permeation Chromatography) measurement using a GPC (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40°C, flow rate: 1.0 mL/min, detector: differential refractive index detector).

In this specification, the acid dissociation constant (pKa) refers to the pKa in aqueous solution. Specifically, it is a value calculated based on the values of the Hammett substituent constant and the database of known literature values using the following software package 1. The pKa values described in this specification are all values calculated using the software package.

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. As a specific method, a method of calculating the H ⁺ dissociation free energy in an aqueous solution based on a thermodynamic cycle can be cited. Regarding the calculation method of H ⁺ dissociation free energy, for example, it can be calculated by DFT (density functional theory), but there are also various other methods reported in the literature, and the calculation method is not limited to this. In addition, there are a variety of software that can implement DFT, for example, Gaussian16 can be cited.

As mentioned above, the pKa in this specification refers to the value obtained by calculation based on the Hammett substituent constant and the value of the database of known literature values using software package 1. However, when the pKa cannot be calculated using this method, the value obtained using Gaussian16 based on DFT (density functional theory) is adopted. In addition, as mentioned above, the pKa in this specification refers to "pKa in aqueous solution". When the pKa in aqueous solution cannot be calculated, the "pKa in dimethyl sulfoxide (DMSO) solution" is adopted.

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

In this specification, the so-called solid component means the component forming the photoresist film, excluding the solvent. Moreover, if it is a component forming the photoresist film, it is also regarded as a solid component even if its property is liquid.

[Actogenic radiation or radiation-sensitive resin composition] The actinogenic radiation or radiation-sensitive resin composition of the present invention (hereinafter also referred to as "photoresist composition") comprises: (A) an onium salt compound; and (B) a polymer, wherein the polymer has repeating units and the main chain is decomposed by irradiation with actinic rays or radiation, wherein the repeating units contain acidic groups having acidic protons, and the polymer has repeating units represented by the following general formula (1).

[Chemical formula 11]

In the general formula (1), Y represents a hydrogen atom or a alkyl group. ^A2 represents an aromatic ring group having an electron donating group. The electron donating group is not equivalent to the acidic group.

The photoresist composition of the present invention can form a pattern with excellent sensitivity and excellent LWR performance in ultrafine pattern formation by means of the above structure. The reason is not clear, but the inventors speculate as follows. The polymer (B) contained in the photoresist composition of the present invention is a polymer whose main chain is decomposed by irradiation with actinic rays or radiation, and has a repeating unit represented by the above formula (1). Since the aromatic ring group bonded to the main chain has an electron-donating group, the electron density in the aromatic ring becomes high, which has the effect of stabilizing the intermediates in the main chain decomposition process, thereby promoting the decomposition of the main chain of the polymer (B). As a result, the sensitivity of the photoresist composition of the present invention is improved, and the dissolution contrast between the unexposed part and the exposed part of the photoresist film formed using the photoresist composition of the present invention is increased, thereby obtaining excellent LWR performance. Furthermore, the polymer (B) contained in the photoresist composition of the present invention has a repeating unit, and the repeating unit contains an acidic group having an acidic proton. Since the acidic group having an acidic proton is a group that can interact with the onium salt compound (A) in the photoresist composition, in the unexposed part of the photoresist film formed using the photoresist composition of the present invention, the onium salt compound (A) interacts with the polymer (B) and is difficult to dissolve in the developer. On the other hand, after exposure, the main chain of the polymer (B) decomposes, the interaction between the onium salt compound (A) and the polymer (B) is released, and it tends to be easily dissolved in the developer. That is, it can be considered that the dissolution contrast between the unexposed part and the exposed part of the photoresist film is increased by the above-mentioned effect, thereby being able to obtain better sensitivity and LWR performance. Hereinafter, the sensitivity of the photoresist composition being better and/or the LWR performance of the pattern formed by the photoresist composition being better are also referred to as "the effect of the present invention being better".

Hereinafter, various components included in the photoresist composition will be described first.

[Onium salt compound (A)] The photoresist composition of the present invention preferably contains an onium salt compound (A). As the onium salt compound (A), a compound having an onium salt structure that generates an acid by irradiation with actinic rays or radiation (photodegradable onium salt compound) is preferred. When the photoresist composition contains an onium salt compound (A) such as a photodegradable onium salt compound, in the unexposed part, the polymer (B) is easily aggregated with the onium salt compound (A) via an acidic group having an acidic proton that may be contained in the polymer (B). On the other hand, when exposed, dissociation between the onium salt compound (A) and the acidic group having an acidic proton or cleavage of the photodegradable onium salt compound occurs, thereby releasing the above-mentioned aggregate structure. That is, through the above-mentioned effect, the dissolution contrast between the unexposed part and the exposed part of the photoresist film is further increased, thereby being able to obtain the effect of the present invention.

The photodegradable onium salt compound is described below. The photodegradable onium salt compound is preferably a compound having at least one salt structure site composed of an anion site and a cation site, and generating an acid (preferably an organic acid) by decomposition under light exposure. Among them, the above-mentioned salt structure site of the photodegradable onium salt compound is preferably composed of an organic cation site and an organic anion site with extremely low nucleophilicity from the viewpoint of easy decomposition by light exposure and better generation of organic acid. The above-mentioned salt structure site may be a part of the photodegradable onium salt compound or the whole. In addition, when the salt structure part is a part of the photodegradable onium salt compound, for example, as in the photodegradable onium salt PG2 described later, it is equivalent to a structure obtained by linking two or more salt structure parts. The number of salt structure parts in the photodegradable onium salt is not particularly limited, and is preferably 1 to 10, more preferably 1 to 6, and further preferably 1 to 3.

Examples of the organic acid generated from the photodegradable onium salt compound by exposure include sulfonic acid (aliphatic sulfonic acid, aromatic sulfonic acid, and camphorsulfonic acid), carboxylic acid (aliphatic carboxylic acid, aromatic carboxylic acid, and aralkyl carboxylic acid), carbonylsulfonyl imide acid, bis(alkylsulfonyl)imidic acid, and tris(alkylsulfonyl)methide acid. In addition, the organic acid generated from the photodegradable onium salt compound by exposure may also be a polybasic acid having two or more acid groups. For example, when the photodegradable onium salt compound is the photodegradable onium salt compound PG2 described later, the organic acid generated by the decomposition of the photodegradable onium salt compound by exposure becomes a polybasic acid having two or more acid groups.

In the photodegradable onium salt compound, the cationic site constituting the salt structure site is preferably an organic cationic site, and among them, the organic cation represented by the formula (ZaI) (cation (ZaI)) or the organic cation represented by the formula (ZaII) (cation (ZaII)) described later is preferred.

(Photodegradable onium salt compound PG1) As an example of a preferred embodiment of the photodegradable onium salt compound, there can be cited an onium salt compound represented by "M ⁺ X ^- " and generating an organic acid by exposure (hereinafter also referred to as "photodegradable onium salt compound PG1"). In the compound represented by "M ⁺ X ^- ", M ⁺ represents an organic cation, and X ^- represents an organic anion. The photodegradable onium salt compound PG1 is described below.

The organic cation represented by M ⁺ in the photodegradable 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)).

[Chemical formula 12]

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

Preferred examples 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)) described later.

First, the cation (ZaI-1) is explained. The cation (ZaI-1) is an aryl zirconia cation, wherein at least one of R ²⁰¹ to R ²⁰³ in the above formula (ZaI) is an aryl zirconia cation. In the aryl zirconia cation, R ²⁰¹ to R ²⁰³ may all be aryl groups, or some of R ²⁰¹ to R ²⁰³ may be aryl groups and the rest may be alkyl groups or cycloalkyl groups. Furthermore, 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, or an oxygen atom, a sulfur atom, an ester group, an amide group or a carbonyl group may be contained in the ring. Examples of the group formed by two of R ²⁰¹ to R ²⁰³ being bonded include alkylene groups (e.g., butylene, pentylene, and -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -), wherein one or more methylene groups may be substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and/or a carbonyl group. Examples of the aryl zirconia cation include triaryl zirconia cations, diaryl alkyl zirconia cations, aryl dialkyl zirconia cations, diaryl cycloalkyl zirconia cations, and aryl dicycloalkyl zirconia cations.

The aromatic group contained in the aromatic coronium cation is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aromatic group may be an aromatic group having a heterocyclic structure containing 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 aromatic coronium cation has two or more aromatic groups, the two or more aromatic groups may be the same or different. The arylthium cation may optionally have an alkyl or cycloalkyl group, 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, more preferably, for example, methyl, ethyl, propyl, n-butyl, sec-butyl, t-butyl, cyclopropyl, cyclobutyl, and cyclohexyl.

As substituents that the aryl, alkyl and cycloalkyl groups of R ²⁰¹ to R ²⁰³ may have, each independently preferably an alkyl group (e.g., having 1 to 15 carbon atoms), a cycloalkyl group (e.g., having 3 to 15 carbon atoms), an aryl group (e.g., having 6 to 14 carbon atoms), an alkoxy group (e.g., having 1 to 15 carbon atoms), a cycloalkylalkoxy group (e.g., having 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 and a phenylthio group. The above substituents may further have substituents, and for example, the above alkyl group may have a halogen atom as a substituent and may be a halogenated alkyl group such as a trifluoromethyl group.

Next, the cation (ZaI-2) will be described. The cation (ZaI-2) is a cation in which R ²⁰¹ to R ²⁰³ in the formula (ZaI) each independently represent an organic group having no aromatic ring. The aromatic ring herein also includes an aromatic ring containing a heteroatom. The organic group having no aromatic ring as R ²⁰¹ to R ²⁰³ usually has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. R ²⁰¹ to R ²⁰³ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and further preferably a linear or branched 2-oxoalkyl group.

As the alkyl group and cycloalkyl group for R ²⁰¹ to R ²⁰³ , for example, there can be mentioned a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (for example, methyl, ethyl, propyl, butyl and pentyl), and a cycloalkyl group having 3 to 10 carbon atoms (for example, cyclopentyl, cyclohexyl and norbornyl). R ²⁰¹ to R ²⁰³ may be further substituted by a halogen atom, an alkoxy group (for example, 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).

[Chemical formula 13]

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 tert-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 the ring may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the above-mentioned ring include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterocyclic rings, and polycyclic condensed rings formed by combining two or more of these rings. Examples of the ring include 3-10 membered rings, preferably 4-8 membered rings, and more preferably 5- or 6-membered rings.

As the group formed by the bonding of any two or more of R _1c to R _5c , R _6c and R _7c , and R _x and R _y , there can be mentioned alkylene groups such as butylene and pentylene. The methylene group in the alkylene group may be substituted by a heteroatom such as an oxygen atom. As the group formed by the bonding of R _5c and R _6c , and R _5c and R _x , it is preferably a single bond or an alkylene group. As the alkylene group, there can be mentioned methylene and ethylene.

R _1c to R _5c , R _6c , R _7c , R _x , R _y , and a ring formed by 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 bonding to each other may 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).

[Chemical formula 14]

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 (for example, a fluorine atom, an iodine atom, etc.), a hydroxyl group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a group containing a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a portion of a cycloalkyl group). These groups may have a substituent. R ₁₄ represents a hydroxyl group, a halogen atom (for example, a fluorine atom, an iodine atom, etc.), an alkyl group, a halogenated alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group containing a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a portion of a cycloalkyl group). These groups may have a substituent. When there are plural R ₁₄ , each independently represents the above-mentioned groups such as a hydroxyl group. R ₁₅ independently represents an alkyl group, a cycloalkyl group or a naphthyl group. Two R _{15 groups} may be bonded to each other to form a ring. When two R ₁₅ groups 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 preferred that two R ₁₅ groups are alkylene groups and are bonded to each other to form a ring structure. In addition, the above-mentioned alkyl group, the above-mentioned cycloalkyl group and the above-mentioned naphthyl group, and the ring formed by two R ₁₅ groups being bonded 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 carbon number of the alkyl group is preferably 1 to 10. More preferably, the alkyl group is methyl, ethyl, n-butyl or t-butyl.

Next, the formula (ZaII) is described. In the formula (ZaII), R ²⁰⁴ and R ²⁰⁵ each independently represent an aryl group, an alkyl group, or a cycloalkyl group. As the aryl group of R ²⁰⁴ and R ²⁰⁵ , a phenyl group or a naphthyl group is preferred, and a phenyl group is more preferred. The aryl group of R ²⁰⁴ and R ²⁰⁵ may be an aryl group having a heterocyclic ring, and the heterocyclic ring has an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the skeleton of the aryl group having a heterocyclic ring include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. The alkyl group and cycloalkyl group as R ²⁰⁴ and R ²⁰⁵ are preferably a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl or pentyl), or a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl or norbornyl).

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

As the organic anion represented by ^X- in the photodegradable onium salt compound PG1, a non-nucleophilic anion (anion having extremely low ability to cause a nucleophilic reaction) is preferred. Examples of the non-nucleophilic anion include sulfonic acid anions (aliphatic sulfonic acid anions, aromatic sulfonic acid anions, and camphorsulfonic acid anions), carboxylic acid anions (aliphatic carboxylic acid anions, aromatic carboxylic acid anions, and aralkyl carboxylic acid anions), sulfonimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

As the organic anion, for example, an organic anion represented by the following formula (DA) may be used.

[Chemical formula 15]

In formula (DA), A ₃₁ ^- represents an anionic group. R _a1 represents a hydrogen atom or a monovalent organic group. _{L a1} represents a single bond or a divalent linking group.

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

[Chemical formula 16]

＊-O ^- formula (B-14)

In formula (B-1) to (B-14), * represents a bonding position. In formula (B-1) to (B-5) and formula (B-12), ^RX1 each independently represents a monovalent organic group. In formula (B-7) and (B-11), ^RX2 each independently represents a substituent other than a hydrogen atom, a fluorine atom and a perfluoroalkyl group. The two ^RX2 in formula (B-7) may be the same or different. In formula (B-8), ^RXF1 represents a hydrogen atom, a fluorine atom or a perfluoroalkyl group. Among them, at least one of the two ^RXF1 represents a fluorine atom or a perfluoroalkyl group. The two ^RXF1 in formula (B-8) may be the same or different. In formula (B-9), ^RX3 represents a hydrogen atom, a halogen atom or a monovalent organic group. n1 represents an integer from 0 to 4. When n1 represents an integer from 2 to 4, a plurality of ^RX3 may be the same or different. In formula (B-10), ^RXF2 represents a fluorine atom or a perfluoroalkyl group. The object to be bonded to the bonding position represented by * in formula (B-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 and the like.

In formulae (B-1) to (B-5) and (B-12), ^RX1 independently represents a monovalent organic group. ^RX1 is preferably an alkyl group (may be linear or branched, preferably having 1 to 15 carbon atoms), a cycloalkyl group (may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms), or an aryl group (may be monocyclic or polycyclic, preferably having 6 to 20 carbon atoms). The above groups represented by ^RX1 may have a substituent. In formula (B-5), the atom directly bonded to ^N- in ^RX1 is preferably any one of a carbon atom other than -CO- and a sulfur atom other than _-SO2- .

The cycloalkyl group in ^RX1 may be monocyclic or polycyclic. Examples of the cycloalkyl group in ^RX1 include norbornyl and adamantyl.

The substituent that the cycloalkyl group in ^RX1 may have is not particularly limited, but is preferably an alkyl group (which may be linear or branched, preferably having 1 to 5 carbon atoms). Among the carbon atoms that are ring members of the cycloalkyl group in ^RX1 , one or more carbon atoms may be substituted by a carbonyl carbon atom.

The carbon number of the alkyl group in ^RX1 is preferably 1 to 10, more preferably 1 to 5. The substituent that the alkyl group in ^RX1 may have is not particularly limited, and for example, a cycloalkyl group, a fluorine atom or a cyano group is preferred. Examples of the cycloalkyl group as the substituent include the cycloalkyl groups described in the case where ^RX1 is a cycloalkyl group. When the alkyl group in ^RX1 has a fluorine atom as the substituent, the alkyl group may be a perfluoroalkyl group. In addition, one or more _-CH2- groups in the alkyl group in ^RX1 may be substituted by a carbonyl group.

The aryl group in ^RX1 is preferably a phenyl ring group. The substituent that the aryl group in ^RX1 may have is not particularly limited, but is preferably an alkyl group, a fluorine atom or a cyano group. Examples of the alkyl group as the above substituent include the alkyl groups described in the case where ^RX1 is an alkyl group.

In formula (B-7) and (B-11), ^RX2 each independently represents a substituent other than a hydrogen atom, a fluorine atom, and a perfluoroalkyl group (for example, an alkyl group not containing a fluorine atom and a cycloalkyl group not containing a fluorine atom can be mentioned). The two ^RX2 in formula (B-7) may be the same or different.

In formula (B-8), ^RXF1 represents a hydrogen atom, a fluorine atom or a perfluoroalkyl group. Among the plural ^RXF1 , at least one represents a fluorine atom or a perfluoroalkyl group. The two ^RXF1 in formula (B-8) may be the same or different. The carbon number of the perfluoroalkyl group represented by ^RXF1 is preferably 1 to 15, more preferably 1 to 10, and even more preferably 1 to 6.

In formula (B-9), ^RX3 represents a hydrogen atom, a halogen atom or a monovalent organic group. Examples of the halogen atom of ^RX3 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. The monovalent organic group of ^RX3 is the same as the monovalent organic group described as ^RX1 . n1 represents an integer of 0 to 4. n1 is preferably an integer of 0 to 2, and is preferably 0 or 1. When n1 represents an integer of 2 to 4, a plurality of ^RX3 may be the same or different.

In formula (B-10), ^RXF2 represents a fluorine atom or a perfluoroalkyl group. The perfluoroalkyl group represented by ^RXF2 preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms.

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

As an alkyl group, it can be a straight chain or a branched chain, preferably an alkyl group with 1 to 20 carbon atoms, more preferably an alkyl group with 1 to 15 carbon atoms, and more preferably an alkyl group with 1 to 10 carbon atoms. As a cycloalkyl group, it can be a monocyclic or polycyclic group, preferably a cycloalkyl group with 3 to 20 carbon atoms, more preferably a cycloalkyl group with 3 to 15 carbon atoms, and more preferably a cycloalkyl group with 3 to 10 carbon atoms. As an aryl group, it can be a monocyclic or polycyclic group, preferably an aryl group with 6 to 20 carbon atoms, more preferably an aryl group with 6 to 15 carbon atoms, and more preferably an aryl group with 6 to 10 carbon atoms.

The cycloalkyl group may contain a heteroatom as a ring member atom. The heteroatom is not particularly limited, and examples thereof include a nitrogen atom, an oxygen atom, etc. In addition, the cycloalkyl group may contain a carbonyl bond (>C=O) as a ring member atom. The above-mentioned 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 of L _a1 is not particularly limited, and represents an alkylene group, a cycloalkylene group, an aromatic group, -O-, -CO-, -COO-, and a group formed by combining two or more of them. The alkylene group may be a linear or branched chain, preferably having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms. The cycloalkylene group may be a monocyclic or polycyclic group, preferably having 3 to 20 carbon atoms, more preferably 3 to 10 carbon atoms. The aromatic group is a divalent aromatic group, preferably an aromatic group having 6 to 20 carbon atoms, more preferably an aromatic group having 6 to 15 carbon atoms. The aromatic ring constituting the aromatic group is not particularly limited, and for example, an aromatic ring having 6 to 20 carbon atoms can be cited, and specifically, a benzene ring, a naphthalene ring, an anthracene ring, and a thiophene ring can be cited. As the aromatic ring constituting the aromatic group, a benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred. The alkylene group, the cycloalkylene group, and the aromatic group may further have a substituent, and the substituent is preferably a halogen atom. As L _a1 , it is preferred to represent a single bond.

As the photodegradable onium salt compound PG1, for example, it is also preferable to use the photoacid generator disclosed in paragraphs [0135] to [0171] of International Publication No. 2018/193954, paragraphs [0077] to [0116] of International Publication No. 2020/066824, and paragraphs [0018] to [0075] and [0334] to [0335] of International Publication No. 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 further preferably 1,000 or less.

(Photodegradable onium salt compound PG2) In addition, as another preferred example of the photodegradable onium salt compound, the following compound (I) and compound (II) can be cited (hereinafter, "compound (I) and compound (II)" are also referred to as "photodegradable onium salt compound PG2"). The photodegradable onium salt compound PG2 is a compound having two or more salt structure sites described above and generating a polyvalent organic acid by exposure. The photodegradable onium salt compound PG2 is described below.

<<Compound (I)>> Compound (I) is a compound having one or more of the following structural sites X and one or more of the following structural sites Y, and is a compound that generates an acid comprising the following first acid site derived from the following structural site X and the following second acid site derived from the following structural site Y by irradiation with actinic rays or radiation. Structural site X: A structural site consisting of anionic site A ₁ ^- and cationic site M ₁ ⁺ , and forming a first acid site represented by HA ₁ by irradiation with actinic rays or radiation Structural site Y: A structural site consisting of anionic site A ₂ ^- and cationic site M ₂ ⁺ , and forming a second acid site represented by HA ₂ by irradiation with actinic rays or radiation Wherein, compound (I) satisfies the following condition I.

Condition I: In the compound (1), the compound PI obtained by replacing the cationic site _M1 ⁺ in the structural site X and the cationic site _M2 ⁺ in the structural site Y with H ⁺ has an acid dissociation constant a1 of the acidic site represented by _HA1 obtained by replacing the cationic site _M1 ⁺ in the structural site X with H ⁺ , and an acid dissociation constant a2 of the acidic site represented by _HA2 obtained by replacing the cationic site _M2 ⁺ in the structural site Y with H ⁺ , and the acid dissociation constant a2 is greater than the acid dissociation constant a1. The compound PI is equivalent to an acid generated when the 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. Furthermore, the two or more A ₁ ^- and the two or more M ₁ ⁺ may be the same or different. Furthermore, in compound (I), the A ₁ ^- and the A ₂ ^- , and the M ₁ ⁺ and the M ₂ ⁺ may be the same or different, but the A ₁ ^- and the A ₂ ^- are preferably different.

The anionic site A ₁ ^- and the anionic site A ₂ ^- are structural sites containing negatively charged atoms or atomic groups, and examples thereof include structural sites 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. ^RA represents a monovalent organic group. Examples of the monovalent organic group represented by ^RA include cyano, trifluoromethyl, and methanesulfonyl.

[Chemical formula 17]

The cationic site _M1 ⁺ and the cationic site _M2 ⁺ are structural sites containing positively charged atoms or atomic groups, and examples thereof include monovalent organic cations. The organic cations are not particularly limited, but are preferably organic cations represented by the above formula (ZaI) (cations (ZaI)) or organic cations represented by the formula (ZaII) (cations (ZaII)).

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

The compound (II) is irradiated with actinic rays or radiation to produce a compound PII (acid) having an acidic site represented by HA ₁ obtained by replacing the cationic site M ₁ ⁺ in the structural site X with H ⁺ . That is, the compound PII represents a compound having the acidic site represented by HA ₁ and a structural site Z that is a non-ionic site capable of neutralizing the acid. In the compound (II), the definition of the structural site X and the definitions of A ₁ ^- and M ₁ ⁺ are the same as those of the structural site X and the definitions of A ₁ ^- and M ₁ ⁺ in the compound (I), and the preferred embodiment is also the same. In addition, the two or more structural sites X may be the same or different. In addition, the two or more A ₁ ^- and the two or more M ₁ ⁺ may be the same or different.

The non-ionic part capable of neutralizing the acid in the structural part Z is not particularly limited, and for example, it is preferably a part containing a group that can electrostatically interact with protons or a functional group having electrons. As the group that can electrostatically interact with protons or the functional group having electrons, there can be cited a functional group having a macrocyclic structure such as a cyclic polyether or a functional group having a nitrogen atom containing a non-shared electron pair that does not contribute to π conjugation. The so-called nitrogen atom containing a non-shared electron pair that does not contribute to π conjugation is, for example, a nitrogen atom having a partial structure shown in the following formula.

[Chemical formula 18] Unshared electron pairs

Examples of the partial structure of the group capable of electrostatically interacting with protons or the functional group having electrons include crown ether structure, nitrogen-doped crown ether structure, primary to tertiary amine structure, pyridine structure, imidazole structure, and pyrazine structure, among which primary to tertiary amine structure is 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 the photodegradable onium salt compound PG2, the compounds exemplified in paragraphs [0023] to [0095] of International Publication No. 2020/158313 can be cited.

An example of a site other than a cation that the photodegradable onium salt compound PG2 may have is shown below.

[Chemical formula 19]

[Chemical formula 20]

In the photoresist composition of the present invention, the content of the onium salt compound (A) is preferably 0.1 to 20% by mass relative to the total solid content of the photoresist composition. If it is 0.1% by mass or more, the dissolution contrast between the unexposed part and the exposed part due to the presence or absence of interaction with the acidic group having acidic protons in the polymer (B) increases, and the effect of the present invention is easily obtained. The lower limit of the content is preferably 0.5% by mass or more, further preferably 1.0% by mass or more, and particularly preferably 2.0% by mass or more. In addition, if the above content is 20% by mass or less, the unexposed part will have appropriate solubility and better sensitivity, and the effect of the present invention is still easy to obtain. The upper limit of the content is preferably 10.0% by mass or less, and further preferably 5.0% by mass or less. The onium salt (A) may be used alone or in combination of two or more. When two or more are used, it is preferred that the total content thereof be within the above-mentioned preferred content range.

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

The polymer (B) is a so-called main chain-cutting type polymer in which the main chain is decomposed (the main chain is cut) by irradiation with actinic rays or radiation. The polymer (B) is preferably a polymer in which the main chain is decomposed by irradiation with X-rays, electron beams or extreme ultraviolet rays, and more preferably a polymer in which the main chain is decomposed by irradiation with electron beams or extreme ultraviolet rays.

The polymer (B) is preferably a copolymer containing a repeating unit represented by the following general formula (1) and a repeating unit that enables the polymer (B) to function as a main chain cleaving polymer (preferably a repeating unit represented by the following general formula (2)). The polymer (B) may be a random copolymer, a block copolymer, or an alternating copolymer, and is more preferably an alternating copolymer.

<Repeating units containing an acidic group having an acidic proton> The polymer (B) has a repeating unit containing an acidic group having an acidic proton. The acidic group having an acidic proton functions as a group that interacts with the onium salt compound (A). The acidic group having an acidic proton represents at least one group selected from the group consisting of a phenolic hydroxyl group, a carboxyl ^group , _-SO2NHRN ( ^RN 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, and a cyano group), an amide group, a carbonylimide group, a sulfonimide group, a thiol group substituted on a ring member atom of an aromatic ring, and -C(=O) _NHSO2RP ^{(RP represents} an alkyl group or an aryl group). The phenolic hydroxyl group refers to a hydroxyl group substituted on a ring member atom of an aromatic ring.

As the alkyl group of ^RN , the alkyl group exemplified as the organic group W described later is preferred, and a linear or branched alkyl group having 1 to 6 carbon atoms is more preferred, and a methyl group or a tert-butyl group is further preferred, and a methyl group is particularly preferred. As the alkyl group in the alkylcarbonyl group of ^RN , the alkyl group exemplified as the organic group W described later is preferred, and a linear or branched alkyl group having 1 to 6 carbon atoms is more preferred, and a methyl group or a tert-butyl group is further preferred, and a methyl group is particularly preferred. As the aryl group of ^RN, phenyl, naphthyl, anthracenyl, etc. are exemplified, and a phenyl group is particularly preferred. As the aryl group in the arylcarbonyl group of ^RN , phenyl, naphthyl, anthracenyl, etc. are exemplified, and a phenyl group is particularly preferred. As the alkoxycarbonyl group of ^RN , methyl ester and ethyl ester are exemplified, and a methyl ester is particularly preferred. The alkyl group in the alkylsulfonyl group of ^RN is preferably an alkyl group exemplified as the organic group W described later, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, further preferably a methyl group or a tert-butyl group, and particularly preferably a methyl group. The aryl group in the arylsulfonyl group of ^RN includes phenyl, naphthyl, anthracenyl, etc., and particularly preferably a phenyl group.

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

[Chemical formula 21]

In the general formulae (K1) and (K2), * represents each substitution position. In the general formula (K2), R ^K represents an alkyl group or an aryl group.

The alkyl group for R ^K is preferably an alkyl group exemplified as the organic group W described below, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, further preferably a methyl group or a tert-butyl group, and particularly preferably a methyl group. The aryl group for R ^K includes a phenyl group, a naphthyl group, an anthracenyl group, and the like, and particularly preferably a phenyl group. R ^K may further have a substituent. As the substituent, a halogen atom is preferred, and a fluorine atom is more preferred.

Furthermore, the carbonyl imide group is preferably a group represented by the following general formula (M1) or (M2).

[Chemical formula 22]

In the general formulae (M1) and (M2), * represents each substitution position. In the general formula (M2), ^RM represents an alkyl group or an aryl group.

As the alkyl group of ^RM , the alkyl group exemplified as the organic group W described later is preferred, and a linear or branched alkyl group having 1 to 6 carbon atoms is more preferred, and a methyl group or a tert-butyl group is further preferred, and a methyl group is particularly preferred. As the aryl group of ^RM , phenyl, naphthyl, anthracenyl, etc. can be mentioned, and a phenyl group is particularly preferred. ^RM may further have a substituent. As the substituent, a halogen atom is preferred, and a fluorine atom is more preferred.

The aromatic ring to which the thiol group is bonded is not particularly limited, and may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. Furthermore, the aromatic ring may be a monocyclic ring or a polycyclic ring. Specifically, the groups exemplified as the aromatic ring in the aromatic ring group possessed by ^A2 in the general formula (1) described later can be cited. The same applies to the aromatic ring to which the hydroxyl group in the phenolic hydroxyl group is bonded.

The alkyl group represented by ^RP is preferably an alkyl group exemplified as the organic group W described below, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or a tert-butyl group. The aryl group represented by ^RP is preferably an aryl group exemplified as the organic group W described below, more preferably an aryl group having 6 to 10 carbon atoms, and more preferably a phenyl group.

The acidic group having an acidic proton is preferably at least one group selected from a phenolic hydroxyl group, a carboxyl ^group , _-SO2NHRN ( ^RN represents a hydrogen atom, an alkylcarbonyl group, or an arylcarbonyl group), an alkylsulfonyl group, an arylsulfonyl group, and a thiol group substituted on a ring member atom of an aromatic ring, and more preferably at least one group selected from a phenolic hydroxyl group and a carboxyl group.

The repeating unit containing an acidic group having an acidic proton may be a repeating unit represented by the general formula (1) described below, a repeating unit represented by the general formula (2), or another repeating unit different from the general formula (1) and the general formula (2). Preferably, it is at least one of the repeating unit represented by the general formula (1) and the repeating unit represented by the general formula (2), and more preferably, it is a repeating unit represented by the general formula (1). The specific structure of the repeating unit will be described later.

In the polymer (B), the content of repeating units containing acidic groups with acidic protons is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 40 mol% or more relative to all repeating units. Moreover, as its upper limit, for example, it is preferably 95 mol% or less, more preferably 90 mol% or less, further preferably 80 mol% or less, and particularly preferably 60 mol% or less relative to all repeating units. In addition, in the polymer (B), the repeating units containing acidic groups with acidic protons may include one type alone or two or more types. When two or more types are included, it is preferred that the total content is within the above-mentioned preferred content range.

<Repeating units represented by general formula (1)>

[Chemical formula 23]

In the general formula (1), Y represents a hydrogen atom or a alkyl group. ^A2 represents an aromatic ring group having an electron donating group. The electron donating group is not equivalent to the acidic group.

In the general formula (1), Y represents a hydrogen atom or a alkyl group. As the alkyl group represented by Y, there can be mentioned a linear or branched alkyl group, a cycloalkyl group, and an aryl group. As the linear or branched alkyl group represented by Y, an alkyl group exemplified as the organic group W described below is preferred, an alkyl group having 1 to 6 carbon atoms is more preferred, and a methyl group or an ethyl group is further preferred. As the cycloalkyl group represented by Y, a cycloalkyl group exemplified as the organic group W described below is preferred, and a cyclopentyl group or a cyclohexyl group is more preferred. As the aryl group represented by Y, an aryl group exemplified as the organic group W described below is preferred, and a phenyl group or a naphthyl group is more preferred.

Y is preferably methyl or ethyl, more preferably methyl.

In the general formula (1), ^A2 represents an aromatic ring group having an electron donating group. The electron donating group is not equivalent to the acidic group. As the aromatic ring in the aromatic ring group possessed by ^A2 , an aromatic hydrocarbon ring and an aromatic heterocyclic ring can be cited. The aromatic ring can be a monocyclic ring or a polycyclic ring. There is no particular limitation on the aromatic hydrocarbon ring, and for example, an aromatic hydrocarbon ring having 6 to 20 carbon atoms can be cited. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, and an acenaphthene ring can be cited, and a benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred. The aromatic heterocyclic ring is not particularly limited, and examples thereof include aromatic heterocyclic rings having 3 to 20 carbon atoms (heteroatoms contained in the ring include oxygen atoms, sulfur atoms, nitrogen atoms, etc.). Specifically, examples thereof include thiophene rings, furan rings, pyridine rings, imidazole rings, benzimidazole rings, benzothiazole rings, etc., preferably thiophene rings, furan rings, benzimidazole rings, benzothiazole rings, and more preferably benzimidazole rings and benzothiazole rings.

The aromatic ring in the aromatic ring group possessed by ^A2 is preferably an aromatic hydrocarbon ring, more preferably a benzene ring.

As the electron donating group possessed by the aromatic ring group, preferably, an electron donating group having a Hammett's substituent constant σp value of less than 0 can be cited.

Here, the Hammett substituent constant σ value is a numerical expression of the effect of the substituent on the acid dissociation equilibrium constant of substituted benzoic acid, and is a parameter indicating the strength of the electron-withdrawing and electron-donating properties of the substituent. In this specification, the Hammett substituent constant σp value (hereinafter also referred to as "σp value") means the substituent constant σ when the substituent is located at the para position of benzoic acid. In this specification, the σp value of each group adopts the value described in the literature "Hansch et al., Chemical Reviews, 1991, Vol. 91, No.2, 165-195". In addition, for groups for which the σp value is not given in the above literature, the σp value can be calculated based on the difference between the pKa of benzoic acid and the pKa of benzoic acid derivatives with substituents 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, more preferably -0.1 or less. The lower limit of the σp value of the electron donating group is not particularly limited, but is preferably -0.9 or more.

As electron-donating groups having a Hammett substituent constant σp value less than 0, for example, alkyl groups, alkoxy groups, alkylthio groups, dialkylamino groups, monoalkylamino groups, etc. can be cited. As the electron-donating group, the alkyl group is preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and preferably a methyl group (σp=-0.17). As the electron-donating group, the alkyl part of the alkoxy group is preferably the above-mentioned alkyl group. The alkoxy group is preferably a methoxy group (σp=-0.27). As the electron-donating group, the alkyl part of the alkylthio group is preferably the above-mentioned alkyl group. The alkylthio group is preferably an ethylthio group (σp=-0.1). As the electron-donating group, the alkyl part of the dialkylamino group is preferably the above-mentioned alkyl group. The two alkyl groups in the dialkylamino group may be the same or different. The dialkylamine group is preferably a dimethylamine group (σp=-0.83).

The electron donating group is preferably at least one group selected from an alkyl group, an alkoxy group, an alkylthio group, a dialkylamino group, and a monoalkylamino group, more preferably at least one group selected from an alkoxy group, an alkylthio group, a dialkylamino group, and a monoalkylamino group, and further preferably at least one group selected from a dialkylamino group and a monoalkylamino group.

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

The above-mentioned aromatic ring group may have a substituent other than the electron-donating group. Among them, it is preferred to further contain an acidic group having the above-mentioned acidic proton. In this case, the repeating unit represented by the general formula (1) is equivalent to the above-mentioned repeating unit containing an acidic group having an acidic proton. The above-mentioned aromatic ring group may be directly bonded to the electron-donating group, or may be bonded to the electron-donating group via a divalent linking group. As a divalent linking group, a divalent linking group as ^L2 in the general formula (1-2) described later can be cited.

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

[Chemical formula 24]

In the general formula (1-2), Y represents a hydrogen atom or a alkyl group. ^R2 represents an acidic group having an acidic proton. When there are multiple ^R2s , the multiple ^R2s may be the same or different. ^R3 represents an electron donating group. When there are multiple ^R3s , the multiple ^R3s may be the same or different. Wherein, the above electron donating group is not equivalent to the above acidic group. ^L2 represents a single bond or a divalent linking group. m represents an integer of 1 to 4. n represents an integer of 1 to 4. Wherein, 1≤m+n≤5 is satisfied.

Y in the general formula (1-2) has the same meaning as Y in the general formula (1), and preferred examples are also the same. As the acidic group having an acidic proton represented by ^R2 in the general formula (1-2), the above-mentioned acidic groups having an acidic proton can be cited, and preferred examples are also the same. As the electron-donating group represented by ^R3 in the general formula (1-2), the above-mentioned electron-donating groups having a Hammett's substituent constant σp value of less than 0 can be cited, and preferred examples are also the same.

The divalent linking group as ^L2 is not particularly limited, and examples thereof include alkylene, -O-, -C(=O)-, -S-, _-SO2- , or a group formed by combining two or more of these. The alkylene may be linear or branched, and examples thereof include alkylene having 1 to 6 carbon atoms.

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

Specific examples of monomers constituting the repeating unit represented by the general formula (1) are given below, but the present invention is not limited thereto.

[Chemical formula 25]

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 further preferably 40 mol% or more relative to all repeating units. Moreover, as an upper limit, for example, it is preferably 95 mol% or less, more preferably 90 mol% or less, further preferably 80 mol% or less, and particularly preferably 60 mol% or less relative to all repeating units. In addition, in the polymer (B), the repeating unit represented by the general formula (1) may contain one type alone or two or more types. When containing two or more types, it is preferred that the total content is within the above-mentioned preferred content range.

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

[Chemical formula 26]

In the general formula (2), X represents a halogen atom. ^L1 represents -O- or ^-NR1- . ^R1 represents a hydrogen atom or an organic group. ^A1 represents a hydrogen atom or an organic group. ^R0 represents a hydrogen atom or an organic group. ^R0 may be linked to ^A1 or ^R1 to form a ring.

In the general formula (2), X represents a halogen atom. As the halogen atom represented by X, there can be cited fluorine atom, chlorine atom, bromine atom, and iodine atom. Among them, as the halogen atom represented by X, from the viewpoint of better effect of the present invention, a chlorine atom, a bromine atom, or an iodine atom is preferred, and a chlorine atom is more preferred.

The organic group represented by R ¹ , R ⁰ and A ¹ is not particularly limited, and examples thereof include the groups exemplified in the organic group W described below. (Organic group W) Examples of the organic group W include alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, heteroaryl, aralkyl, cyano, alkoxy, aryloxy, heterocyclic oxy, acyl (alkylcarbonyl or arylcarbonyl), acyloxy (alkylcarbonyloxy or arylcarbonyloxy), carbamoyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, alkylthio, arylthio, heterocyclic thio, alkyl or arylsulfinyl, alkyl or arylsulfonyl, aryloxycarbonyl, alkoxycarbonyl, aryl or heterocyclic azo, sulfonamide, imide, amide, carbamoyl, and lactone. If possible, each of the above groups may further have a substituent. For example, as one form of the organic group W, an alkyl group that may have a substituent is also included. The substituent is not particularly limited, and examples thereof include one or more of the groups represented by the organic group W, a halogen atom, a nitro group, a primary to a tertiary amine group, a phosphine group, a phosphine group, a phosphineoxy group, a phosphineamine group, a phosphonyl group, a silane group, a hydroxyl group, a carboxyl group, a sulfonic acid group, and a phosphoric acid group (hereinafter, these are also referred to as "substituents T"). The number of carbon atoms in the organic group W is, for example, 1 to 20. The number of atoms other than hydrogen atoms in the organic group W is, for example, 1 to 30.

In addition, the carbon number of the alkyl group exemplified as the organic group W is preferably 1 to 20, more preferably 1 to 10, and further preferably 1 to 6. The alkyl group may be any of a linear chain and a branched chain. As the alkyl group, for example, a linear chain or branched chain alkyl group such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, and an n-hexyl group may be cited. Among the alkyl groups that may have a substituent, the substituent that the alkyl group may have is not particularly limited, and for example, the groups exemplified by the substituent T mentioned above may be cited.

As the alkyl moiety in the alkoxy group (including the alkoxy moiety in the substituent group containing the alkoxy group (for example, alkoxycarbonyloxy group)), the alkyl moiety in the aralkyl group, the alkyl moiety in the alkylcarbonyl group, the alkyl moiety in the alkylcarbonyloxy group, the alkyl moiety in the alkylthio group, the alkyl moiety in the alkylsulfinyl group, and the alkyl moiety in the alkylsulfonyl group exemplified in the organic group W, the above-mentioned alkyl groups are preferred. In addition, in the alkoxy group which may have a substituent, the aralkyl group which may have a substituent, the alkylcarbonyloxy group which may have a substituent, the alkylthio group which may have a substituent, the alkylsulfinyl group which may have a substituent, and the alkylsulfonyl group which may have a substituent, the same substituent as the substituent in the alkyl group which may have a substituent can be cited.

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

The alkenyl group exemplified in the organic group W may be any of a linear and branched chain. The carbon number of the alkenyl group is preferably 2 to 20. In the alkenyl group which may have a substituent, the substituent that the alkenyl group may have may be the same as the substituent in the alkyl group which may have a substituent. The cycloalkenyl group exemplified in the organic group W preferably has 5 to 20 carbon atoms. In the cycloalkenyl group which may have a substituent, the substituent that the cycloalkenyl group may have may be the same as the substituent in the alkyl group which may have a substituent. The alkynyl group exemplified in the organic group W may be any of a linear, branched chain and cyclic chain. The carbon number of the alkynyl group is preferably 2 to 20. In the alkynyl group which may have a substituent, the substituent that the alkynyl group may have may be the same as the substituent in the alkyl group which may have a substituent. The carbon number of the cycloalkynyl group exemplified in the organic group W is preferably 5 to 20. In the cycloalkynyl group which may have a substituent, the substituents which the cycloalkynyl group may have can be the same as the substituents in the alkyl group which may have a substituent.

Unless otherwise specified, the aryl group exemplified in the organic group W may be either monocyclic or polycyclic (e.g., 2-6 rings, etc.). The number of ring member atoms of the above aryl group is preferably 6-15, more preferably 6-10. As the above aryl group, phenyl, naphthyl or anthracenyl is preferred, and phenyl is more preferred. In the aryl group that may have a substituent, the substituent that the aryl group may have can be the same as the substituent in the alkyl group that may have a substituent. In addition, in the group exemplified in the organic group W, the aryl part in the substituent containing an aryl group (e.g., aryloxy group) can also be the same as the aryl group exemplified in the above organic group W.

Unless otherwise specified, the heteroaryl group exemplified in the organic group W may be either monocyclic or polycyclic (e.g., 2 to 6 rings, etc.). The number of heteroatoms that the heteroaryl group has as ring member atoms is, for example, 1 to 10. As the above-mentioned heteroatoms, for example, nitrogen atoms, sulfur atoms, oxygen atoms, selenium atoms, tellurium atoms, phosphorus atoms, silicon atoms, and boron atoms can be cited. The number of ring member atoms of the above-mentioned heteroaryl group is preferably 5 to 15. In the heteroaryl group that may have a substituent, the substituent that the heteroaryl group may have can be the same as the substituent in the alkyl group that may have a substituent.

The heterocyclic ring exemplified in the organic group W means a ring containing a heteroatom as a ring member atom, and unless otherwise specified, it may be any of an aromatic heterocyclic ring and an aliphatic heterocyclic ring, and may be any of a monocyclic ring and a polycyclic ring (for example, 2 to 6 rings, etc.). The number of heteroatoms that the heterocyclic ring has as a ring member atom is, for example, 1 to 10. As the above-mentioned heteroatoms, for example, nitrogen atoms, sulfur atoms, oxygen atoms, selenium atoms, tellurium atoms, phosphorus atoms, silicon atoms, and boron atoms can be cited. The number of ring member atoms of the above-mentioned heterocyclic ring is preferably 5 to 15. In the heterocyclic ring that may have a substituent, the substituent that the heterocyclic ring may have can be the same as the substituent in the alkyl group that may have a substituent.

As the lactone group exemplified in the organic group W, a lactone group having 5 to 7 ring members is preferred, and a lactone group having 5 to 7 ring members and having another ring structure condensed on the lactone ring to form a bicyclic structure or a spirocyclic structure is more preferred. In the lactone group which may have a substituent, the substituents which the lactone group may have may be the same as those in the alkyl group which may have a substituent.

As R ⁰ , a hydrogen atom is preferred. As R ¹ , a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred.

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

^R0 can be linked to ^A1 or ^R1 to form a ring. The ring formed by ^R0 and ^A1 or ^R1 is not particularly limited, and can be any of a monocyclic ring and a polycyclic ring. The above ring can contain a heteroatom such as an oxygen atom, a nitrogen atom, and a sulfur atom, and/or a carbonyl carbon as a ring member atom. The above ring is preferably a 5- or 6-membered alicyclic ring.

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

[Chemical formula 27]

In the general formula (2-2), X represents a halogen atom. ^A1 represents a hydrogen atom or an organic group. ^R0 represents a hydrogen atom or an organic group. ^R0 may be linked to ^A1 to form a ring.

X, ^A1 and ^R0 in the general formula (2-2) have the same meanings as X, ^A1 and ^R0 in the above general formula (2), and preferred embodiments are also the same.

Specific examples of monomers constituting the repeating unit represented by the general formula (2) are listed below, but the present invention is not limited thereto.

[Chemical formula 28]

[Chemical formula 29]

In polymer (B), the content of the repeating unit represented by general formula (2) is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 40 mol% or more relative to all repeating units. Moreover, as its upper limit, it is preferably 90 mol% or less, more preferably 80 mol% or less, further preferably 70 mol% or less, and particularly preferably 60 mol% or less relative to all repeating units. In polymer (B), the repeating unit represented by general formula (2) may contain one type alone or two or more types. When containing two or more types, it is preferred that the total content is within the above-mentioned preferred content range.

<Other repeating units> The polymer (B) may also contain other repeating units other than the above-mentioned repeating units within the range that does not affect the effect of the present invention. Specifically, for example, it may contain repeating units represented by the following general formula (3). In addition, among the repeating units represented by the general formula (3), those equivalent to the repeating units represented by the above-mentioned general formula (1) are regarded as the repeating units represented by the general formula (1).

[Chemical formula 30]

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

Examples of the alkyl group represented by Y ³ in the general formula (3) include the alkyl groups represented by Y in the general formula (1). Y ³ is preferably a methyl group or an ethyl group, and more preferably a methyl group.

In the general formula (3), Ar represents an aryl group which may have a substituent. As the aryl group which may have a substituent, the aryl group exemplified as the organic group W is preferred, and the phenyl group which may have a substituent is more preferred. As the substituent which the aryl group may have, for example, the same substituent as the alkyl group which may have a substituent as the organic group W can be cited. Ar preferably represents an aryl group which has a substituent, and the substituent contains a halogen atom. In other words, Ar is preferably an aryl group which has a substituent containing a halogen atom. When the aryl group has a halogen atom as a substituent, the number of halogen atoms is not particularly limited, and for example, 1 to 5 are preferred, and 1 to 3 are more preferred.

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

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

[Chemical formula 31]

When the polymer (B) contains other repeating units, the content thereof is preferably 30 mol % or less, more preferably 15 mol % or less, relative to all repeating units.

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

The weight average molecular weight of the polymer (B) is preferably 5,000 or more, more preferably 10,000 or more, and further preferably 20,000 or more. In addition, the weight average molecular weight of the polymer (B) is preferably 200,000 or less, more preferably 150,000 or less, further preferably 100,000 or less, and particularly preferably 85,000 or less. The above weight average molecular weight value is a value obtained by the GPC method as a polystyrene conversion value. The dispersity (molecular weight distribution) of the polymer (B) is usually 1.0 to 3.0, preferably 1.0 to 2.0, more preferably 1.0 to 1.8, and further preferably 1.0 to 1.6. When the dispersity is within the above range, the resolution and resist shape tend to be more excellent.

The polymer (B) can be synthesized by conventional methods (e.g., free radical polymerization). Details of the synthesis are shown in the Examples.

In the photoresist composition of the present invention, the content of polymer (B) relative to the total solid content of the composition is preferably 50.0 mass % or more, more preferably 60.0 mass % or more, and further preferably 70.0 mass % or more. In addition, the upper limit is 100 mass % or less, preferably 99.9 mass % or less. Polymer (B) can be used alone or in combination. When two or more types are used, it is preferred that their total content is within the above-mentioned preferred content range.

<Solvent> The photoresist composition of the present invention preferably contains a solvent. The solvent preferably includes at least one of (M1) and (M2), wherein (M1) is propylene glycol monoalkyl ether carboxylate, and (M2) is at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate, acetate, alkoxy propionate, chain ketone, cyclic ketone, lactone and alkyl carbonate. In addition, the solvent may further contain components other than components (M1) and (M2).

When such a solvent and a polymer (B) are used in combination, the coating property of the photoresist composition can be improved, and a pattern with a small number of development defects can be easily formed. The reason for this is presumably that such a solvent is excellent in the balance of solubility, boiling point and viscosity of the polymer (B), and thus can suppress the unevenness of the film thickness of the photoresist film as a composition film of the photoresist composition and the generation of precipitates during spin coating.

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

As component (M2), the following components are preferred. As propylene glycol monoalkyl ether, propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether (PGEE) are preferred. As lactic acid ester, ethyl lactate, butyl lactate or propyl lactate is preferred. As acetate, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate or 3-methoxybutyl acetate is preferred. In addition, butyl butyrate is also preferred. As 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, propiophenone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetone alcohol, acetylmethanol, acetophenone, methyl naphthyl ketone, or methyl amyl ketone are preferred. As the cyclic ketone, methyl cyclohexanone, isophorone, cyclopentanone, or cyclohexanone are preferred. As the lactone, γ-butyrolactone is preferred. As the alkyl carbonate, propyl carbonate is preferred.

As the component (M2), propylene glycol monomethyl ether (PGME), ethyl lactate, ethyl 3-ethoxypropionate, methyl amyl ketone, cyclohexanone, butyl acetate, amyl acetate, γ-butyrolactone, or propylene carbonate is more preferred.

As a solvent, in addition to the above components, it is also preferred to contain an ester solvent having a carbon number of 7 or more (preferably 7 to 14, more preferably 7 to 12, and further preferably 7 to 10) and a heteroatom number of 2 or less. As an ester solvent having a carbon number of 7 or more and a heteroatom number of 2 or less, amyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, amyl propionate, hexyl propionate, butyl propionate, isobutyl isobutyrate, heptyl propionate, or butyl butyrate is preferred, and isoamyl acetate is more preferred.

As component (M2), preferably, the flash point (hereinafter, also referred to as fp) is 37°C or above. As such component (M2), preferably, 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), amyl acetate (fp: 45°C), methyl 2-hydroxyisobutyrate (fp: 45°C), γ-butyrolactone (fp: 101°C), or propylene carbonate (fp: 132°C). Among them, more preferably, propylene glycol monoethyl ether, ethyl lactate, amyl acetate or cyclohexanone, and more preferably, propylene glycol monoethyl ether or ethyl lactate. In addition, the so-called "flash point" here refers to the value listed in the reagent catalog of Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Corporation.

The solvent preferably contains component (M1). The solvent preferably consists essentially of component (M1) alone, or is a mixed solvent of component (M1) and other components. In the latter case, the solvent more preferably contains both component (M1) and component (M2). The mass ratio (M1/M2) of component (M1) to 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 further preferably in the range of "100/0" to "60/40". That is, the solvent preferably contains only component (M1), or contains both component (M1) and component (M2), and the mass ratio is as shown below. That is, in the latter case, the mass ratio of component (M1) to component (M2) is preferably 15/85 or more, more preferably 40/60 or more, and further preferably 60/40 or more. By adopting this structure, the number of development defects can be further reduced.

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

When 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 photoresist composition of the present invention is preferably set to a solid component concentration of 0.5 to 30 mass %, more preferably 1 to 20 mass %, from the viewpoint of having better coating properties.

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

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

When the photoresist composition of the present invention contains a surfactant, the content of the surfactant is preferably 0.0001 to 2% by mass, more preferably 0.0005 to 1% by mass, relative to the total solid content of the photoresist composition.

Furthermore, the present invention relates to an actinic radiation-sensitive or radiation-sensitive resin composition, comprising: (A) an onium salt compound; and (B1) a polymer, wherein the polymer has repeating units containing at least one group selected from the group consisting of a phenolic hydroxyl group, a carboxyl group, _-SO2NHRN ^{(RN represents} a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group), an amide group, a carbonylimide group, a sulfonimide group, a thiol group substituted on a ^{ring member atom of an aromatic ring, and/or -C(=O)NHSO2RP (RP} _represents ^an alkyl group or an aryl group), wherein the polymer has repeating units represented by the following general formula (1) and repeating units represented by the following general formula (2).

[Chemical formula 32]

In the general formula (1), Y represents a hydrogen atom or a alkyl group. ^A2 represents an aromatic ring group having an electron-donating group. The electron-donating group is not equivalent to the at least one group mentioned above.

[Chemical formula 33]

In the general formula (2), X represents a halogen atom. ^L1 represents -O- or ^-NR1- . ^R1 represents a hydrogen atom or an organic group. ^A1 represents a hydrogen atom or an organic group. ^R0 represents a hydrogen atom or an organic group. ^R0 may be linked to ^A1 or ^R1 to form a ring.

(A) The onium salt compound is as described above. The polymer (B1) is a preferred embodiment of the polymer (B). At least one group selected from the group consisting ^of a phenolic hydroxyl group, a carboxyl group, _-SO2NHRN ( ^RN represents a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl ^group , an arylsulfonyl group, a cyano group), an amide group, a carbonylimide group, a sulfonimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O) _NHSO2RP ( ^RP represents an alkyl group or an aryl group) is the "acidic group having an acidic proton" in the polymer (B). In addition, each group in the general formula (1) and the general formula (2) has the same meaning as each group in the general formula (1) and the general formula (2) of the polymer (B). The repeating unit containing an acidic group having an acidic proton may be a repeating unit represented by the general formula (1) or a repeating unit represented by the general formula (2), or may be another repeating unit different from the general formulas (1) and (2). Preferably, it is at least one of the repeating unit represented by the general formula (1) and the repeating unit represented by the general formula (2), and more preferably, it is a repeating unit represented by the general formula (1).

The polymer preferably contains a repeating unit represented by the general formula (1-2) and a repeating unit represented by the general formula (2-2). The polymer may contain other repeating units other than the above-mentioned repeating units within the range that does not affect the effect of the present invention. As other repeating units, the same as other repeating units that the polymer (B) may contain can be cited. The content of the repeating unit represented by the general formula (1) and the content of the repeating unit represented by the general formula (2) are the same as the content of the repeating unit represented by the general formula (1) and the content of the repeating unit represented by the general formula (2) in the polymer (B). In addition, the content of other repeating units is also the same as the content of other repeating units in the polymer (B).

[Photoresist film, pattern forming method] The present invention also relates to a photoresist film formed using an actinic radiation-sensitive or radiation-sensitive resin composition. Furthermore, the present invention also relates to a pattern forming method, which comprises: a process of forming a photoresist film on a substrate using the actinic radiation-sensitive or radiation-sensitive resin composition; a process of exposing the photoresist film; and a process of developing the exposed photoresist film using a developer.

The steps of the pattern forming method using the above-mentioned photoresist composition are not particularly limited, and preferably have the following processes. Process 1: Process of forming a photoresist film on a substrate using a photoresist composition Process 2: Process of exposing the photoresist film Process 3: Process of developing the above-mentioned exposed photoresist film using a developer The steps of each of the above processes will be described in detail below.

<Process 1: Photoresist film forming process> Process 1 is a process for forming a photoresist film on a substrate using a photoresist composition. The definition of the photoresist composition is as described above.

As a method of forming a photoresist film on a substrate using a photoresist composition, for example, a method of coating the photoresist composition on a substrate can be cited. In addition, it is preferred to filter the photoresist composition with a filter as needed before coating. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.05 μm or less, and further preferably 0.03 μm or less. In addition, the filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

The photoresist composition can be applied to a substrate (e.g., coated with silicon or silicon dioxide) such as that used to manufacture integrated circuit components by an appropriate coating method such as a spin coater or a coater. The coating method is preferably rotary coating using a spin coater. The rotation speed when using a spinner for rotary coating is preferably 1000 to 3000 rpm. After applying the photoresist composition, the substrate can be dried and a photoresist film can be formed. In addition, various base coating films (inorganic films, organic films, anti-reflective films) can be formed on the lower layer of the photoresist film as needed.

As a drying method, for example, a method of drying by heating can be cited. Heating can be implemented by a device equipped in a common exposure machine and/or developer, or can be implemented using a hot plate or the like. The heating temperature is preferably 80 to 150° C., more preferably 80 to 140° C., and further preferably 80 to 130° C. The heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, and further preferably 60 to 600 seconds.

The thickness of the photoresist film is not particularly limited, but from the perspective of forming a fine pattern with higher precision, it is preferably 10 to 120 nm. In the case of EUV exposure and EB exposure, the thickness of the photoresist film is more preferably 10 to 65 nm, and more preferably 15 to 50 nm. In the case of ArF immersion exposure, the thickness of the photoresist film is more preferably 10 to 120 nm, and more preferably 15 to 90 nm.

In addition, a top coating composition can be used to form a top coating on the upper layer of the photoresist film. The top coating composition is preferably not mixed with the photoresist film and can be evenly coated on the upper layer of the photoresist film. The top coating is not particularly limited, and a previously known top coating can be formed by a previously known method. For example, the top coating can be formed based on the description of paragraphs [0072] to [0082] of Japanese Patent Publication No. 2014-059543. For example, it is preferred to form a top coating containing an alkaline compound as described in Japanese Patent Publication No. 2013-61648 on the photoresist film. Specific examples of alkaline compounds that can be included in the top coating include alkaline compounds that can be included in the photoresist composition. In addition, the top coating is also preferably a compound containing at least one group or bond selected from the group consisting of ether bonds, thioether bonds, hydroxyl groups, thiol groups, carbonyl bonds, and ester bonds.

<Process 2: Exposure process> Process 2 is a process for exposing the photoresist film. As a method of exposure, a method of irradiating the formed photoresist film through a prescribed mask can be cited. As actinic rays or radiation, infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams can be cited. Far ultraviolet light with a wavelength of less than 250nm is preferred, less than 220nm is more preferred, and particularly preferably 1 to 200nm is preferred. Specifically, KrF excimer laser (248nm), ArF excimer laser (193nm), _F2 excimer laser (157nm), EUV (13nm), X-rays, and electron beams can be cited.

After exposure, it is preferred to perform post-exposure heat treatment (also called post-exposure baking) before development. Post-exposure heat treatment can promote the reaction of the exposed part, thereby making the sensitivity and pattern shape better. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and more preferably 80 to 130°C. The heating time is preferably 10 to 1000 seconds, more preferably 10 to 180 seconds, and more preferably 30 to 120 seconds. Heating can be implemented by a device equipped in a conventional exposure machine and/or developer, or by using a hot plate, etc.

<Process 3: Development process> Process 3 is a process for developing the exposed photoresist film using a developer to form a pattern. The developer is preferably a developer containing an organic solvent (hereinafter also referred to as an organic developer).

As developing methods, for example, there can be cited a method of immersing a substrate in a tank filled with developer for a certain period of time (immersion method), a method of developing by accumulating developer on the substrate surface by surface tension and allowing it to stand for a certain period of time (liquid coating method), a method of spraying developer on the substrate surface (spraying method), and a method of continuously spraying developer while scanning a developer discharge nozzle at a certain speed on a substrate rotating at a certain speed (dynamic distribution method). In addition, after the development process, a process of stopping the development while replacing with another solvent can also be implemented. The development time is not particularly limited as long as it is a time for the resin in the unexposed part to be fully dissolved, and is preferably 10 to 300 seconds, and more preferably 20 to 120 seconds. The temperature of the developer is preferably 0-50°C, more preferably 15-35°C.

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

The above solvents may be mixed in multiple forms, or may be mixed with solvents other than the above or water. The water content of the developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, further preferably less than 10% by mass, and particularly preferably substantially free of water. The content of the organic solvent relative to 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, further 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, relative to the total amount of the developer.

<Other processes> The above-mentioned pattern forming method is preferably a process including a cleaning process with a rinse solution after process 3.

The rinse solution used in the rinse process after the development process 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. The rinse solution is preferably a rinse solution 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 process is not particularly limited. For example, there can be cited a method of continuously spraying a rinsing liquid onto a substrate rotating at a certain speed (spin coating method), a method of immersing a substrate in a tank filled with a rinsing liquid for a certain period of time (immersion method), and a method of spraying a rinsing liquid onto the surface of a substrate (spraying method). In addition, the pattern forming method of the present invention can include a heating process (Post Bake) after the rinsing process. By this process, the developer and rinsing liquid remaining between and inside the patterns are removed by baking. In addition, by this process, the photoresist pattern is annealed and the surface roughness of the pattern is improved. The heating process after the rinsing process is usually carried out at 40-250℃ (preferably 90-200℃) for 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

Furthermore, the formed pattern can be used as a mask to perform etching processing on the substrate. That is, the pattern formed in process 3 can be used as a mask to process the substrate (or the lower film and the substrate) to form a pattern on the substrate. The processing method of the substrate (or the lower film and the substrate) is not particularly limited, but it is preferably a method of forming a pattern on the substrate by dry etching the substrate (or the lower film and the substrate) using the pattern formed in process 3 as a mask. Dry etching is preferably oxygen plasma etching.

The various materials used in the photoresist composition and the pattern forming method of the present invention (e.g., solvent, developer, rinse solution, anti-reflection film forming composition, top coating forming composition, etc.) are preferably free of impurities such as metal. The content of impurities contained in these materials is preferably 1 mass ppm or less, more preferably 10 mass ppb or less, further preferably 100 mass ppt or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. Here, as metal impurities, for example, Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn can be cited.

As a method for removing impurities such as metal from various materials, for example, filtration using a filter can be cited. Details of filtration using a filter are described in paragraph [0321] of International Publication No. 2020/004306.

In addition, as a method for reducing impurities such as metals contained in various materials, for example, there are a method of selecting raw materials with a low metal content as raw materials constituting various materials, a method of filtering the raw materials constituting various materials with a filter, and a method of forming an inner lining in an apparatus using Teflon (TEFLON, registered trademark) to perform distillation under conditions that suppress contamination as much as possible.

In addition to filter filtration, impurities can be removed by using adsorbent materials, or filter filtration and adsorbent materials can be used in combination. As adsorbent materials, known adsorbent materials can be used, for example, inorganic adsorbent materials such as silica gel and zeolite, and organic adsorbent materials such as activated carbon can be used. In order to reduce impurities such as metals contained in the above-mentioned materials, it is necessary to prevent the mixing of metal impurities in the manufacturing process. Whether the metal impurities have been fully removed from the manufacturing device can be confirmed by measuring the content of metal components contained in the cleaning solution used to clean the manufacturing device. The content of metal components contained in the cleaning solution after use is preferably less than 100 mass ppt (parts per trillion), more preferably less than 10 mass ppt, and further preferably less than 1 mass ppt.

In addition, the photoresist composition sometimes contains water as an impurity. When containing water as an impurity, the content of water is preferably as small as possible, and may also contain 1 to 30,000 mass ppm relative to the entire photoresist composition. In addition, the photoresist composition sometimes contains residual monomers (for example, monomers derived from raw material monomers used to synthesize polymer (B)) as impurities. When containing residual monomers as impurities, the content of residual monomers is preferably as small as possible, and may also contain 1 to 30,000 mass ppm relative to the total solid content of the photoresist composition.

Conductive compounds can be added to organic treatment liquids such as rinse liquids to prevent electrostatic charging and subsequent electrostatic discharge, and prevent malfunctions in liquid piping and various components (filters, O-rings, tubes, etc.). There are no particular restrictions on the conductive compound, and methanol can be cited as an example. There are no particular restrictions on the amount of addition, but from the perspective of maintaining better developing characteristics or cleaning characteristics, it is preferably 10% by mass or less, and more preferably 5% by mass or less. As liquid piping, for example, SUS (stainless steel) or various piping coated with polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene or perfluoroalkoxy resin, etc.) that has been treated with anti-static treatment can be used. Similarly, for filters and O-rings, polyethylene, polypropylene or fluororesins (polytetrafluoroethylene or perfluoroalkoxy resins, etc.) that have been treated with antistatic agents can also be used.

[Manufacturing method of electronic device] In addition, the present invention also relates to a manufacturing method of an electronic device including the above-mentioned pattern forming method, and an electronic device manufactured by the manufacturing method. The electronic device of the present invention can be preferably mounted on electrical and electronic equipment (home appliances, OA (Office Automation), media-related equipment, optical equipment, communication equipment, etc.).

[Polymer] The present invention also relates to a polymer having a repeating unit as a preferred embodiment of the polymer (B), wherein the repeating unit contains an acidic group having an acidic proton, and the polymer comprises a repeating unit represented by the general formula (1) and a repeating unit represented by the general formula (2), wherein the acidic group represents at least one group selected from the group consisting ^{of a phenolic hydroxyl group, a carboxyl group, -SO2NHRN (RN} _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, a carbonylimide group, a sulfonimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O) _NHSO2RP ^{( RP} represents an alkyl group or an aryl group).

The repeating unit containing an acidic group having an acidic proton may be a repeating unit represented by the general formula (1) or a repeating unit represented by the general formula (2), or may be another repeating unit different from the general formulas (1) and (2). Preferably, it is at least one of the repeating unit represented by the general formula (1) and the repeating unit represented by the general formula (2), and more preferably, it is a repeating unit represented by the general formula (1).

The polymer preferably contains a repeating unit represented by the general formula (1-2) and a repeating unit represented by the general formula (2-2). The polymer may contain other repeating units other than the above-mentioned repeating units within the scope that does not affect the effect of the present invention. As other repeating units, the same as other repeating units that the polymer (B) may contain can be cited. The content of the repeating unit represented by the general formula (1) and the content of the repeating unit represented by the general formula (2) are the same as the content of the repeating unit represented by the general formula (1) and the content of the repeating unit represented by the general formula (2) in the polymer (B). In addition, the content of other repeating units is also the same as the content of other repeating units in the polymer (B). [Example]

The present invention is described in more detail below based on the embodiments. The materials, usage amounts, ratios, processing contents, and processing steps shown in the following embodiments can be appropriately changed as long as they do not deviate from the main purpose of the present invention. Therefore, the scope of the present invention should not be interpreted in a restrictive manner by the embodiments shown below.

[Various components of the photosensitive or radiation-sensitive resin composition] [Polymer (B)] The polymers (B-1 to B-23 and RB-1 to RB-3) shown in Table 2 are as follows. B-3 is synthesized by the synthesis method (Synthesis Example 1) described later. B-1 to 2, B-4 to B-23, and RB-1 to RB-3 are synthesized according to Synthesis Example 1 or a known method. In addition, polymers RB-1 to RB-3 are equivalent to comparative polymers. Table 1 shows the compositions of polymers B-1 to B-23 and RB-1 to RB-3 (type of raw material monomers, composition ratio of repeating units (mol%), weight average molecular weight (Mw), and dispersion (Mw/Mn). The weight average molecular weight (Mw) and dispersion (Mw/Mn) of polymers B-1 to B-23 and RB-1 to RB-3 were measured by GPC (carrier: tetrahydrofuran (THF)) (polystyrene equivalent). The composition ratio (mol%) of the polymers was measured by ¹³ C-NMR (Nuclear Magnetic Resonance).

[Table 1]

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

[Chemical formula 34]

[Chemical formula 35]

[Chemical formula 36]

In addition, in M-1 to M-20, the σp value of each group showing an electron donating group is less than 0.

<Synthesis Example 1: Synthesis of polymer B-3>

[Chemical formula 37]

Under a nitrogen flow, 5.33 g of cyclohexanone was placed in a three-necked flask and heated to 85°C. Next, a mixed solution of 11.92 g of monomer M-3, 6.08 g of monomer Ma-1, 0.58 g of a 20 mass% cyclohexanone solution of polymerization initiator V-601 (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.), and 21.1 g of cyclohexanone was added dropwise to the three-necked flask over 4 hours. After the addition was completed, the mixture was further reacted at 85°C for 2 hours. After the reaction was completed, the reaction solution was cooled. Next, the cooled reaction solution was added dropwise to 300 g of stirred heptane/ethyl acetate (9/1), and the powder precipitated by the addition was collected by filtration and dried to obtain resin B-3 (7.5 g).

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

[Onium salt compound (A)] The structures of the onium salt compounds (A-1 to A-12) shown in Table 2 are as follows. In addition, the onium salt compounds (A-1 to A-12) are all equivalent to photodegradable onium salt compounds.

[Chemical formula 38]

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

[Preparation of photosensitive radiation or radiation-sensitive resin composition] The components other than the solvent shown in Table 2 were mixed so that the solid component concentration was 1.3% by mass. Next, the obtained mixed solution was filtered with a polyethylene filter with a pore size of 0.03μm to prepare a photoresist composition. Here, the so-called solid component means all components except the solvent. The obtained photoresist composition was used in the examples and comparative examples.

[Pattern formation and evaluation] 〔Pattern formation and evaluation by EUV exposure: Examples 1 to 24, Comparative Examples 1 to 5〕 ＜Pattern formation＞ The composition for forming an underlayer film SHB-A940 (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to a silicon wafer and baked at 205°C for 60 seconds to form an underlayer film with a thickness of 20 nm. On top of it, the photoresist composition shown in Table 2 was applied and baked at 100°C for 60 seconds to form a photoresist film with a thickness of 30 nm. In this way, a silicon wafer with a photoresist film was formed. The silicon wafer with the photoresist film obtained by the above steps was pattern irradiated using an EUV exposure device (manufactured by Exitech, Micro Exposure Tool, NA0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36). Here, a mask with line:space=1:1 was used as a reticle. The exposed photoresist film was baked at 90°C for 60 seconds, developed with butyl acetate for 30 seconds, further rinsed with butyl acetate, and spin-dried to obtain a pattern.

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

＜LWR performance＞ Using a scanning electron microscope (SEM (S-9380II manufactured by Hitachi Ltd.)), a 14nm (1:1) line and space pattern was observed from above the pattern and analyzed with the exposure amount showing the above sensitivity (EOP). The line width of the pattern was observed at any 100 points, and its standard deviation (σ) was calculated. The measured deviation of the line width was evaluated with 3σ (nm). The smaller the value, the better the performance.

[Table 2]

From the results shown in Table 2, it can be seen that the photoresist composition of the embodiment has excellent sensitivity and the LWR performance of the formed pattern is excellent.

[Pattern formation and evaluation by EB exposure: Examples 1A to 24A] Even when the photoresist film is formed using each photoresist composition of the examples and pattern formation is performed by electron beam exposure, the same results as those obtained when pattern formation is performed by EUV exposure are obtained. [Industrial applicability]

According to the present invention, a photosensitive or radiation-sensitive resin composition can be provided, which can form a pattern with excellent sensitivity and excellent LWR performance in ultrafine pattern formation (for example, a line and space pattern with a line width of less than 15nm or a hole pattern with a hole diameter of less than 15nm). In addition, according to the present invention, a photoresist film, a pattern forming method, and a method for manufacturing an electronic device using the above-mentioned photosensitive or radiation-sensitive resin composition can be provided. In addition, according to the present invention, a polymer useful for the above-mentioned photosensitive or radiation-sensitive resin composition can be provided.

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 without departing from the spirit and scope of the present invention. This application is based on the Japanese patent application (Japanese Patent Application No. 2022-138712) filed on August 31, 2022, the contents of which are incorporated herein by reference.

without

without

Claims (11)

A photosensitive or radiation-sensitive resin composition comprises: (A) an onium salt compound; and (B) a polymer, wherein the polymer has a repeating unit and the main chain is decomposed by irradiation with actinic rays or radiation, wherein the repeating unit contains an acidic group having an acidic proton, wherein the polymer has a ^{repeating unit represented by the following general formula (1), wherein the acidic group is selected from a phenolic hydroxyl group, a carboxyl group, -SO2NHRN (RN} _represents ^a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group), an amide group, a carbonylimide group, a sulfonimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O) _NHSO2RP ⁽ R ^P represents at least one group in the group consisting of an alkyl group or an aryl group, [Chemical Formula 1] In the general formula (1), Y represents a hydrogen atom or a alkyl group, and ^A2 represents an aromatic ring group having an electron-donating group, wherein the electron-donating group is not equivalent to the acidic group. The actinic radiation-sensitive or radiation-sensitive resin composition as described in claim 1, wherein the polymer has a repeating unit represented by the following general formula (2): [Chemical formula 2] In the general formula (2), X represents a halogen atom, ^L1 represents -O- or ^-NR1- , ^R1 represents a hydrogen atom or an organic group, ^A1 represents a hydrogen atom or an organic group, ^R0 represents a hydrogen atom or an organic group, and ^R0 may be linked to ^A1 or ^R1 to form a ring. The actinic radiation-sensitive or radiation-sensitive resin composition as claimed in claim 1 or 2, wherein the polymer comprises a repeating unit represented by the following general formula (1-2) and a repeating unit represented by the following general formula (2-2), [Chemical Formula 3] In the general formula (1-2), Y represents a hydrogen atom or a alkyl group, ^R2 represents the acidic group having an acidic proton, and when there are multiple ^R2s , the multiple ^R2s may be the same or different, ^R3 represents an electron donating group, and when there are multiple ^R3s , the multiple ^R3s may be the same or different, wherein the electron donating group is not equivalent to the acidic group, ^L2 represents a single bond or a divalent linking group, m represents an integer of 1 to 4, n represents an integer of 1 to 4, wherein 1≤m+n≤5 is satisfied, [Chemical Formula 4] In the general formula (2-2), X represents a halogen atom, ^A1 represents a hydrogen atom or an organic group, ^R0 represents a hydrogen atom or an organic group, and ^R0 may be linked to ^A1 to form a ring. The actinic radiation-sensitive or radiation-sensitive resin composition as described in claim 1 or 2, wherein the electron-donating group is at least one group selected from alkyl, alkoxy, alkylthio, dialkylamino, and monoalkylamino. The actinic ray or radiation-sensitive resin composition as described in claim 1 or 2, wherein the content of the onium salt compound is 0.1 to 20 mass % relative to the total solid content of the actinic ray or radiation-sensitive resin composition. A polymer having a repeating unit, wherein the repeating unit contains an acidic group having an acidic proton, wherein the polymer comprises a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2), wherein the acidic group represents at least one group selected from the group consisting of a phenolic hydroxyl group, a carboxyl ^group , _-SO2NHRN ( ^RN represents a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group), an amide group, a ^{carbonylimide} group, a sulfonimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O) _NHSO2RP ( ^RP represents an alkyl group or an aryl group), [Chemical Formula 5] In the general formula (1), Y represents a hydrogen atom or a alkyl group, ^A2 represents an aromatic ring group having an electron-donating group, wherein the electron-donating group is not equivalent to the acidic group, [Chemical Formula 6] In the general formula (2), X represents a halogen atom, ^L1 represents -O- or ^-NR1- , ^R1 represents a hydrogen atom or an organic group, ^A1 represents a hydrogen atom or an organic group, ^R0 represents a hydrogen atom or an organic group, and ^R0 may be linked to ^A1 or ^R1 to form a ring. The polymer as claimed in claim 6, comprising a repeating unit represented by the following general formula (1-2) and a repeating unit represented by the following general formula (2-2), [Chemical Formula 7] In the general formula (1-2), Y represents a hydrogen atom or a alkyl group, ^R2 represents the acidic group having an acidic proton, and when there are multiple ^R2s , the multiple ^R2s may be the same or different, ^R3 represents an electron donating group, and when there are multiple ^R3s , the multiple ^R3s may be the same or different, wherein the electron donating group is not equivalent to the acidic group, ^L2 represents a single bond or a divalent linking group, m represents an integer of 1 to 4, n represents an integer of 1 to 4, wherein 1≤m+n≤5 is satisfied, [Chemical Formula 8] In the general formula (2-2), X represents a halogen atom, ^A1 represents a hydrogen atom or an organic group, ^R0 represents a hydrogen atom or an organic group, and ^R0 may be linked to ^A1 to form a ring. A photosensitive or radiation-sensitive resin composition comprising: (A) an onium salt compound; and (B1) ^a polymer having repeating units containing at least one group selected from the group consisting of a phenolic hydroxyl group, a carboxyl group, _-SO2NHRN ( ^RN represents a hydrogen atom, an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group), an amide group, a carbonylimide group, a sulfonimide group, a thiol group substituted on a ring member atom of an aromatic ring, and/or -C(=O) _NHSO2RP ^{(RP represents} an alkyl group or an aryl group), wherein the polymer has repeating units represented by the following general formula (1) and repeating units represented by the following general formula (2), [Chemical Formula 9] In the general formula (1), Y represents a hydrogen atom or a alkyl group, ^A2 represents an aromatic ring group having an electron-donating group, wherein the electron-donating group is not equivalent to the at least one group, [Chemical Formula 10] In the general formula (2), X represents a halogen atom, ^L1 represents -O- or ^-NR1- , ^R1 represents a hydrogen atom or an organic group, ^A1 represents a hydrogen atom or an organic group, ^R0 represents a hydrogen atom or an organic group, and ^R0 may be linked to ^A1 or ^R1 to form a ring. A photoresist film formed using the photosensitive or radiation-sensitive resin composition as described in any one of claims 1 to 5 and 8. A pattern forming method comprising: a process of forming a photoresist film on a substrate using a photosensitive ray or radiation-sensitive resin composition as described in any one of claims 1 to 5 and 8; a process of exposing the photoresist film; and a process of developing the exposed photoresist film using a developer. A method for manufacturing an electronic device, comprising the pattern forming method as described in claim 10.