WO2023145564A1

WO2023145564A1 - Active light–sensitive or radiation-sensitive resin composition, active light–sensitive or radiation-sensitive film, pattern formation method, and production method for electronic device

Info

Publication number: WO2023145564A1
Application number: PCT/JP2023/001305
Authority: WO
Inventors: 太朗三好; 修平山口; 寛大本山
Original assignee: 富士フイルム株式会社
Priority date: 2022-01-28
Filing date: 2023-01-18
Publication date: 2023-08-03
Also published as: JPWO2023145564A1; KR20240123376A; TW202340132A

Abstract

The present invention provides an active light–sensitive or radiation-sensitive resin composition that includes (A) a resin that is degraded and increases in polarity under the action of acid and (C) a compound that generates an acid as a result of being irradiated with active light or radiation, the compound being an ionic compound that has an anion portion that is represented by a specific general formula (I), and the HOMO of the acid being at least -6.50 eV. The present invention also provides an active light–sensitive or radiation-sensitive film, a pattern formation method, a production method for an electronic device, and a compound that use the active light–sensitive or radiation-sensitive resin composition.

Description

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

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

Microfabrication by lithography using a photosensitive composition is performed in the manufacturing process of semiconductor devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integrated Circuits).
A method of lithography includes a method of forming a resist film from a photosensitive composition, exposing the obtained film, and then developing it. In particular, in recent years, in addition to the ArF excimer laser, the use of EB (Electron Beam) and EUV (Extreme Ultraviolet) light during exposure has been studied, and actinic ray-sensitive or radiation-sensitive resins suitable for EUV exposure have been developed. Compositions have been developed.

In the formation of resist patterns using EUV (wavelength 13.5 nm) or electron beams for the purpose of fine pattern formation, various performance requirements are higher than when conventional ArF (wavelength 193 nm) light is used. is getting tougher.

For example, Patent Document 1 discloses (A) a sulfonium salt represented by a specific formula, and (B) a repeating unit represented by a specific formula, which is decomposed by the action of an acid and has high solubility in an alkaline developer. Chemically amplified resist compositions are disclosed which are characterized by containing increasing polymeric compounds.
Further, Patent Document 2 discloses a resist material containing a base polymer and a sulfonium salt represented by a specific formula.

Japanese Patent Application Laid-Open No. 2015-232598 Japanese Patent Application Laid-Open No. 2019-74588

In recent years, miniaturization of patterns formed using EUV light or electron beams has progressed, and further improvements in roughness performance and the like are required.

Therefore, the present invention provides an actinic ray-sensitive or radiation-sensitive resin composition that is extremely excellent in roughness performance in ultrafine pattern formation (for example, line-and-space patterns of 40 nm or less, hole patterns of hole diameters of 40 nm or less, etc.). The task is to
Another object of the present invention is to provide an actinic ray-sensitive or radiation-sensitive film, a pattern forming method, and an electronic device manufacturing method using the actinic ray-sensitive or radiation-sensitive resin composition.

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

[1]
(A) a resin that decomposes under the action of an acid to increase its polarity, and (C) a compound that generates an acid upon irradiation with an actinic ray or radiation, the ion having an anion moiety represented by the following general formula (I): Actinic ray-sensitive or radiation-sensitive resin composition containing a chemical compound,
Actinic ray-sensitive or radiation-sensitive resin composition, wherein the acid has a HOMO of -6.50 eV or more.

In general formula (I),
L ¹ represents a single bond or a divalent linking group.
W represents a hydrocarbon ring or a heterocyclic ring.

[2]
The actinic ray-sensitive or radiation-sensitive resin composition according to [1], wherein the anion moiety represented by the general formula (I) does not correspond to the following (1) and (2).
(1) ring W has one or more selected from the group consisting of -OH, ^-COO- and -COOH as ring members adjacent to the carbon atom bonded to -L ¹ C(=O) ^O-; (2) ring W has, as a ring member, -L ¹ C(=O)O ^- in addition to the carbon atoms bonded to -, one or more carbon atoms, and the ring When W has two or more groups selected from the group consisting of —OH and —COO ^— and —COOH via the one or more carbon atoms as the ring members

[3]
The actinic ray-sensitive or radiation-sensitive resin composition according to [1] or [2], wherein the anion moiety is an anion represented by formula (I)-1.

In general formula (I)-1,
R ¹ to R ² each independently represent a hydrogen atom or a substituent.
^R3 represents a hydrogen atom or a substituent.
^L2 represents a single bond or a divalent linking group.
R ¹ and R ² may combine with each other to form a ring. R ³ and L ² may combine with each other to form a ring.

[4]
The actinic ray-sensitive or radiation-sensitive resin composition according to [2], wherein the anion moiety is an anion represented by (I)-2.

In general formula (I)-2,
R ⁴ and R ⁵ each independently represent a hydrogen atom or a substituent other than OH, COO ^{2 —} and COOH.
R ⁶ to R ⁸ each independently represent a hydrogen atom or a substituent. Two or more of R ⁴ to R ⁸ may combine with each other to form a ring.

[5]
In the above general formula (I)-2, the ring to which the COO ^— group is bonded is a benzene ring as a monocyclic ring, or formed by bonding two or more of R ⁴ to R ⁸ to each other (benzene ring The actinic ray-sensitive or radiation-sensitive according to [4], which is polycyclic and has 6 to 14 carbon atoms as ring members constituting the ring to which the COO ^— group is bonded Resin composition.

[6]
The actinic ray-sensitive or radiation-sensitive resin composition according to [5], wherein the ring to which the COO ^{2 —} group is bonded has 6 to 10 carbon atoms as ring members.

[7]
The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [6], wherein the cation moiety of the ionic compound is a sulfonium cation or an iodonium cation.

[8]
The resin (A) is selected from the group consisting of repeating units represented by the following general formula (A1), repeating units represented by the following general formula (A2), and repeating units represented by the following general formula (A3). The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [7], which has at least one

In general formula (A1),
R ^a1 , R ^a2 and R ^a3 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
L ^a1 represents a single bond or a divalent linking group.
Ar ^a1 represents an aromatic ring group.
R ^a4 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
R ^a5 and R ^a6 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
R ^a4 and R ^a5 may combine with each other to form a ring. Ar ^a1 may combine with R ^a3 or R ^a4 to form a ring.
In general formula (A2),
R ^a7 , R ^a8 and R ^a9 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
^La2 represents a single bond or a divalent linking group.
Ar ^a2 represents an aromatic ring group.
R ^a10 , R ^a11 and R ^a12 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group. Two of R ^a10 , R ^a11 and R ^a12 may combine with each other to form a ring.
In the general formula (A3),
R ^a13 , R ^a14 and R ^a15 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
^La3 represents a single bond or a divalent linking group.
Ar ^a3 represents an aromatic ring group.
R ^a16 , R ^a17 and R ^a18 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group. Two of R ^a16 , R ^a17 and R ^a18 may combine with each other to form a ring.

[9]
The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [8], wherein the resin (A) has a repeating unit having a group that generates an acid upon exposure to actinic rays or radiation. .

[10]
The actinic ray-sensitive or sensitive according to any one of [1] to [9], wherein the content of the ionic compound (C) is 10% by mass or more with respect to the total solid content of the composition. A radioactive resin composition.

[11]
An actinic ray- or radiation-sensitive film formed from the actinic ray- or radiation-sensitive resin composition according to any one of [1] to [10].
[12]
forming an actinic ray-sensitive or radiation-sensitive film on a substrate from the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [10];
exposing the actinic ray-sensitive or radiation-sensitive film;
and developing the exposed actinic ray-sensitive or radiation-sensitive film with a developer to form a pattern.

[13]
A method for manufacturing an electronic device, including the pattern forming method according to [12].

According to the present invention, an actinic ray-sensitive or radiation-sensitive resin composition that is extremely excellent in roughness performance in ultrafine pattern formation (for example, a line-and-space pattern of 40 nm or less and a hole pattern of hole diameter of 40 nm or less) is provided. can provide.
Further, according to the present invention, it is possible to provide an actinic ray-sensitive or radiation-sensitive film, a pattern forming method, and an electronic device manufacturing method using the actinic ray-sensitive or radiation-sensitive resin composition.

The present invention will be described in detail below.
The description of the constituent elements described below may be made based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.
Regarding the notation of a group (atomic group) in the present specification, as long as it does not contradict the spirit of the present invention, the notation that does not describe substituted or unsubstituted includes groups containing substituents as well as groups that do not have substituents. do. For example, an "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). In addition, the term "organic group" as used herein refers to a group containing at least one carbon atom.
As a substituent, a monovalent substituent is preferable unless otherwise specified.

(substituent T)
The substituent T includes halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; an alkoxy group such as a methoxy group, an ethoxy group and a tert-butoxy group; an aryloxy group such as a phenoxy group and a p-tolyloxy group; alkoxycarbonyl groups such as methoxycarbonyl group, butoxycarbonyl group and phenoxycarbonyl group; acyloxy groups such as acetoxy group, propionyloxy group and benzoyloxy group; acetyl group, benzoyl group, isobutyryl group, acryloyl group, methacryloyl group and methoxalyl group, etc. Alkylsulfanyl groups such as a methylsulfanyl group and a tert-butylsulfanyl group; Arylsulfanyl groups such as a phenylsulfanyl group and a p-tolylsulfanyl group; Alkyl groups; Cycloalkyl groups; carboxy group; formyl group; sulfo group; cyano group; alkylaminocarbonyl group; arylaminocarbonyl group; sulfonamide group; silyl group; amino group; and combinations thereof.

As used herein, "actinic ray" or "radiation" means, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV light: Extreme Ultraviolet), X-rays, and electron beams ( EB means Electron Beam).
As used herein, "light" means actinic rays or radiation.
In the present specification, the term "exposure" means, unless otherwise specified, not only exposure by the emission line spectrum of mercury lamps, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV: Extreme ultraviolet), and X-rays, It also includes writing with electron beams and particle beams such as ion beams.
As used herein, the term "to" is used to include the numerical values before and after it as lower and upper limits.

In the present specification, the binding direction of the divalent linking groups indicated is not limited unless otherwise specified. For example, in the compound represented by the formula "XYZ", when Y is -COO-, Y may be -CO-O- or -O-CO- good too. The compound may be "X—CO—O—Z" or "X—O—CO—Z."

As used herein, (meth)acrylate refers to acrylate and methacrylate, and (meth)acryl refers to acrylic and methacrylic.
In the present specification, weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (hereinafter also referred to as "molecular weight distribution") (Mw/Mn) are measured by GPC (Gel Permeation Chromatography) equipment (Tosoh Corporation). GPC measurement (solvent: tetrahydrofuran, flow rate (sample injection volume): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40 ° C., flow rate: 1.0 mL / min, detector : Defined as a polystyrene conversion value by a differential refractive index detector (Refractive Index Detector).

As used herein, the acid dissociation constant (pKa) represents the pKa in an aqueous solution. is a calculated value.
Software Package 1: Advanced Chemistry Development (ACD/Labs) Software V8.14 for Solaris (1994-2007 ACD/Labs).

pKa can also be determined by molecular orbital calculation. As a specific method, there is a method of calculating the H 2 ⁺ dissociation free energy in an aqueous solution based on the thermodynamic cycle. The H ⁺ dissociation free energy can be calculated by, for example, DFT (density functional theory), but various other methods have been reported in literature, etc., and the method is not limited to this. Note that there are a plurality of software that can implement DFT, and Gaussian16 is an example.

In the present specification, pKa refers to a value obtained by calculating a value based on Hammett's substituent constant and a database of known literature values using Software Package 1, as described above. cannot be calculated, a value obtained by Gaussian 16 based on DFT (density functional theory) shall be adopted.
In this specification, pKa refers to "pKa in aqueous solution" as described above, but when pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" is adopted. shall be
"Solid content" means the components that form the actinic ray-sensitive film, and does not include solvent. In addition, as long as it is a component that forms an actinic ray-sensitive film, it is regarded as a solid content even if the property is liquid.

[Actinic ray-sensitive or radiation-sensitive resin composition]
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention is
(A) a resin that decomposes under the action of an acid to increase its polarity, and (C) a compound that generates an acid upon exposure to actinic rays or radiation, and is ionic having an anion represented by the following general formula (I): An actinic ray-sensitive or radiation-sensitive resin composition containing a compound,
The actinic ray-sensitive or radiation-sensitive resin composition, wherein the HOMO of the acid is -6.50 eV or more.

In general formula (I),
L ¹ represents a single bond or a divalent linking group.
W represents a hydrocarbon aromatic ring or a heterocyclic ring.

With such a configuration, the mechanism of extremely excellent roughness performance in ultrafine pattern formation (for example, a line and space pattern of 40 nm or less, a hole pattern of hole diameter of 40 nm or less, etc.) is not clear in detail. It is estimated as follows.
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention contains the above-described ionic compound that generates an acid having a HOMO of -6.50 eV or higher upon exposure to actinic rays or radiation. It is considered that an ionic compound that generates an acid having such a HOMO range tends to emit secondary electrons in an exposed area. As a result, sufficient secondary electrons tend to exist in the exposed area, and an environment is created in which the acid that causes the chemical amplification reaction of the resin (A) is sufficiently easily generated from the acid generator present in the exposed area. As a result, the variation in the reaction of the resin (A) in the exposed area can be suppressed to a high level, so it is considered that the roughness performance is extremely excellent in ultrafine pattern formation.

[Components of actinic ray-sensitive or radiation-sensitive resin composition]
Components that may be contained in the actinic ray-sensitive or radiation-sensitive resin composition are described in detail below.
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention (hereinafter also referred to as "the composition of the present invention") is typically a resist composition, even if it is a positive resist composition. , it may be a negative resist composition. Moreover, it may be a resist composition for alkali development or a resist composition for organic solvent development. The composition of the present invention is typically a chemically amplified resist composition.

<(A) Resin>
Actinic ray-sensitive or radiation-sensitive resin composition composition (hereinafter also referred to as "composition") is a resin (A) (hereinafter also referred to as "resin (A)" that is decomposed by the action of an acid to increase polarity ")including.
The resin (A) is typically an acid-decomposable resin, and usually contains a group that is decomposed by the action of an acid to increase its polarity (hereinafter also referred to as an "acid-decomposable group"). It is preferred to include repeating units having
In the pattern forming method of the present specification, typically, when an alkaline developer is used as the developer, a positive pattern is suitably formed, and when an organic developer is used as the developer, A negative pattern is preferably formed.
As the repeating unit having an acid-decomposable group, a repeating unit having an acid-decomposable group containing an unsaturated bond is preferable in addition to the repeating unit having an acid-decomposable group described below.

(Repeating unit having an acid-decomposable group)
An acid-decomposable group is a group that is decomposed by the action of an acid to form a polar group. The acid-decomposable group preferably has a structure in which the polar group is protected with a group that is released by the action of an acid (leaving group). That is, the resin (A) has a repeating unit having a group that is decomposed by the action of an acid to form a polar group. A resin having this repeating unit has an increased polarity under the action of an acid, thereby increasing the solubility in an alkaline developer and decreasing the solubility in an organic solvent.
The polar group is preferably an alkali-soluble group such as a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group, a sulfonic acid group, a phosphoric acid group, a sulfonamide group, a sulfonylimide group, (alkylsulfonyl)(alkylcarbonyl)methylene group, (alkylsulfonyl)(alkylcarbonyl)imide group, bis(alkylcarbonyl)methylene group, bis(alkylcarbonyl)imide group, bis(alkylsulfonyl)methylene group, bis(alkylsulfonyl)imide group, tris(alkylcarbonyl) Methylene groups, acidic groups such as tris(alkylsulfonyl)methylene groups, and alcoholic hydroxyl groups are included.
Among them, the polar group is preferably a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group.

Examples of groups that leave by the action of an acid include groups represented by formulas (Y1) to (Y4).
Formula (Y1): -C(Rx ₁ )(Rx ₂ )(Rx ₃ )
Formula (Y2): -C(=O)OC(Rx ₁ )(Rx ₂ )(Rx ₃ )
Formula (Y3): —C(R ₃₆ )(R ₃₇ )(OR ₃₈ )
Formula (Y4): -C(Rn)(H)(Ar)

In formula (Y1) and formula (Y2), Rx ₁ to Rx ₃ each independently represent a hydrocarbon group, an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic) , an alkenyl group (linear or branched), or an aryl group (monocyclic or polycyclic). When all of Rx ₁ to Rx ₃ are alkyl groups (linear or branched), at least two of Rx ₁ to Rx ₃ are preferably methyl groups.
Among them, Rx ₁ to Rx ₃ preferably each independently represent a linear or branched alkyl group, and Rx ₁ to Rx ₃ each independently represent a linear alkyl group. is more preferred.
Two of Rx ₁ to Rx ₃ may combine to form a monocyclic or polycyclic ring.
The alkyl groups of Rx ₁ to Rx ₃ are alkyl groups having 1 to 5 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. preferable.
The cycloalkyl groups represented by Rx ₁ to Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, norbornyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups. is preferred. In the cycloalkyl group, for example, one of the ring-constituting methylene groups may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a heteroatom-containing group such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.
The aryl group represented by Rx ₁ to Rx ₃ is preferably an aryl group having 6 to 10 carbon atoms, such as phenyl group, naphthyl group and anthryl group.
A vinyl group is preferable as the alkenyl group for Rx ₁ to Rx ₃ .
The ring formed by combining two of Rx ₁ to Rx ₃ is preferably a cycloalkyl group. The cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ includes a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, and a tetracyclododeca. A polycyclic cycloalkyl group such as a nyl group or an adamantyl group is preferable, and a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferable.
In the cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ , one of the methylene groups constituting the ring is a group containing a heteroatom such as an oxygen atom, a heteroatom such as a carbonyl group, or a vinylidene group. may be replaced with In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.
In the group represented by formula (Y1) or formula (Y2), for example, Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ combine to form the above-described cycloalkyl group. is preferred.
For example, when the composition of the present invention is a resist composition for EUV exposure, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group represented by Rx ₁ to Rx ₃ , and 2 of Rx ₁ to Rx ₃ It is also preferred that the ring formed by combining two atoms further has a fluorine atom or an iodine atom as a substituent.

In formula (Y3), R ₃₆ to R ₃₈ each independently represent a hydrogen atom or a monovalent organic group. R ₃₇ and R ₃₈ may combine with each other to form a ring. Monovalent organic groups include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, and alkenyl groups. It is also preferred that R ₃₆ is a hydrogen atom.
The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a heteroatom such as an oxygen atom and/or a group containing a heteroatom such as a carbonyl group. For example, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, one or more of the methylene groups may be replaced with a heteroatom such as an oxygen atom and/or a group containing a heteroatom such as a carbonyl group. good.
R ₃₈ may combine with another substituent of the main chain of the repeating unit to form a ring. The group formed by bonding R ₃₈ and another substituent of the main chain of the repeating unit to each other is preferably an alkylene group such as a methylene group.
When the composition of the present invention is, for example, a resist composition for EUV exposure, monovalent organic groups represented by R ₃₆ to R 38 and _{R 37} _and R ₃₈ are formed by binding to each other. The ring also preferably has a fluorine atom or an iodine atom as a substituent.

As the formula (Y3), a group represented by the following formula (Y3-1) is preferable.

Here, L ₁ and L ₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group combining these (e.g., a group combining an alkyl group and an aryl group). .
M represents a single bond or a divalent linking group.
Q is an alkyl group optionally containing a heteroatom, a cycloalkyl group optionally containing a heteroatom, an aryl group optionally containing a heteroatom, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group, or a group combining these (for example, a group combining an alkyl group and a cycloalkyl group).
In alkyl groups and cycloalkyl groups, for example, one of the methylene groups may be replaced by a heteroatom such as an oxygen atom or a heteroatom-containing group such as a carbonyl group.
One of L ₁ and L ₂ is preferably a hydrogen atom, and the other is preferably an alkyl group, a cycloalkyl group, an aryl group, or a combination of an alkylene group and an aryl group.
At least two of Q, M, and _L1 may combine to form a ring (preferably a 5- or 6-membered ring).
From the viewpoint of pattern refinement, _L2 is preferably a secondary or tertiary alkyl group, more preferably a tertiary alkyl group. Secondary alkyl groups include isopropyl, cyclohexyl, and norbornyl groups, and tertiary alkyl groups include tert-butyl and adamantane groups. In these embodiments, the Tg (glass transition temperature) and the activation energy are increased, so that the film strength can be ensured and fogging can be suppressed.

When the composition of the present invention is, for example, a resist composition for EUV exposure, the alkyl group, cycloalkyl group, aryl group, and group combining these represented by L ₁ and L ₂ are further It is also preferable to have a fluorine atom or an iodine atom as a substituent. The alkyl group, cycloalkyl group, aryl group, and aralkyl group preferably contain a heteroatom such as an oxygen atom in addition to the fluorine atom and the iodine atom. Specifically, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, for example, one of the methylene groups is replaced with a heteroatom such as an oxygen atom, or a group containing a heteroatom such as a carbonyl group. may be
For example, when the composition of the present invention is a resist composition for EUV exposure, an alkyl group optionally containing a heteroatom represented by Q, a cycloalkyl group optionally containing a heteroatom, or a heteroatom is In the aryl group, amino group, ammonium group, mercapto group, cyano group, aldehyde group, and groups in which these groups may be combined, the heteroatom is selected from the group consisting of a fluorine atom, an iodine atom and an oxygen atom. It is also preferred that the heteroatom is

In formula (Y4), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may combine with each other to form a non-aromatic ring. Ar is preferably an aryl group.
For example, when the resist composition is a resist composition for EUV exposure, the aromatic ring group represented by Ar and the alkyl group, cycloalkyl group and aryl group represented by Rn have fluorine as a substituent. It is also preferred to have an atom or an iodine atom.

From the viewpoint of excellent acid decomposability of the repeating unit, when a non-aromatic ring is directly bonded to a polar group (or a residue thereof) in a leaving group that protects a polar group, in the non-aromatic ring, It is also preferable that the ring member atoms adjacent to the ring member atoms directly bonded to the polar group (or residue thereof) do not have halogen atoms such as fluorine atoms as substituents.

Groups that can be eliminated by the action of an acid also include a 2-cyclopentenyl group having a substituent (such as an alkyl group) such as a 3-methyl-2-cyclopentenyl group, and a 1,1,4,4 A cyclohexyl group having a substituent (such as an alkyl group) such as a -tetramethylcyclohexyl group may also be used.

As the repeating unit having an acid-decomposable group, a repeating unit represented by formula (A) is also preferable.

L ₁ represents a divalent linking group optionally having a fluorine atom or an iodine atom, and R ₁ is a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group optionally having a fluorine atom or an iodine atom , or represents an aryl group optionally having a fluorine atom or an iodine atom, and R ₂ represents a leaving group optionally having a fluorine atom or an iodine atom which is eliminated by the action of an acid. However, at least one of L ₁ , R ₁ and R ₂ has a fluorine atom or an iodine atom.
The divalent linking group optionally having a fluorine atom or an iodine atom represented by L ₁ includes -CO-, -O-, -S-, -SO-, -SO ₂ -, fluorine atom or a hydrocarbon group optionally having an iodine atom (eg, an alkylene group, a cycloalkylene group, an alkenylene group, an arylene group, etc.), and a linking group in which a plurality of these are linked. Among them, L ₁ is preferably -CO-, an arylene group, or an -arylene group - an alkylene group having a fluorine atom or an iodine atom -, and -CO- or an -arylene group - a fluorine atom or an iodine atom. An alkylene group with - is more preferred.
A phenylene group is preferred as the arylene group.
Alkylene groups may be linear or branched. Although the number of carbon atoms in the alkylene group is not particularly limited, it is preferably 1-10, more preferably 1-3.
The total number of fluorine atoms and iodine atoms contained in the alkylene group having fluorine atoms or iodine atoms is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

The alkyl group represented by R ₁ may be linear or branched. Although the number of carbon atoms in the alkyl group is not particularly limited, it is preferably 1-10, more preferably 1-3.
The total number of fluorine atoms and iodine atoms contained in the alkyl group having a fluorine atom or an iodine atom represented by R ₁ is not particularly limited, but is preferably 1 or more, more preferably 1 to 5, and 1 to 3. More preferred.
The alkyl group represented by R ₁ may contain a heteroatom such as an oxygen atom other than the halogen atom.

The leaving group optionally having a fluorine atom or an iodine atom represented by R ₂ is represented by the above formulas (Y1) to (Y4) and having a fluorine atom or an iodine atom. groups.

As the repeating unit having an acid-decomposable group, a repeating unit represented by formula (AI) is also preferable.

In formula (AI),
Xa ₁ represents a hydrogen atom or an organic group.
T represents a single bond or a divalent linking group.
Rx ₁ to Rx ₃ each independently represent a hydrocarbon group.
Two of Rx ₁ to Rx ₃ may combine to form a ring.

The organic group represented by Xa ₁ is preferably an alkyl group. The alkyl group may be linear or branched. Moreover, the said alkyl group may have a substituent. Examples of alkyl groups include methyl groups and groups represented by —CH ₂ —R ₁₁ . R ₁₁ represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. Examples of the monovalent organic group represented by R ₁₁ include an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, an acyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, preferably an alkyl group having 3 or less carbon atoms, and more preferably a methyl group. Xa ₁ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

The divalent linking group for T includes an alkylene group, an aromatic ring group, a --COO--Rt-- group, and a --O--Rt-- group. In the formula, Rt represents an alkylene group or a cycloalkylene group.
T is preferably a single bond or a -COO-Rt- group. When T represents a -COO-Rt- group, Rt is preferably an alkylene group having 1 to 5 carbon atoms, a -CH ₂ - group, a -(CH ₂ ) ₂ - group, or a -(CH ₂ ) ₃ - groups are more preferred.

The hydrocarbon groups of Rx ₁ to Rx ₃ preferably have 1 to 10 carbon atoms. The hydrocarbon group may have a substituent.
The hydrocarbon groups of Rx ₁ to Rx ₃ are preferably alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, or aralkyl groups.
The alkyl groups of Rx ₁ to Rx ₃ may be linear or branched. Moreover, the said alkyl group may have a substituent. The alkyl groups of Rx ₁ to Rx ₃ include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. preferable.
The cycloalkyl groups of Rx ₁ to Rx ₃ may be monocyclic cycloalkyl groups or polycyclic cycloalkyl groups. Moreover, the cycloalkyl group may have a substituent. Cycloalkyl groups of Rx ₁ to Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. is preferred. In the cycloalkyl group, for example, one of the ring-constituting methylene groups may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a heteroatom-containing group such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

The aryl groups of Rx ₁ to Rx ₃ may be monocyclic aryl groups or polycyclic aryl groups. Moreover, the aryl group may have a substituent. The aryl group represented by Rx ₁ to Rx ₃ is preferably an aryl group having 6 to 10 carbon atoms, such as phenyl group, naphthyl group and anthryl group.
The alkenyl groups of Rx ₁ to Rx ₃ may be linear or branched. Moreover, the said alkenyl group may have a substituent. A vinyl group is preferable as the alkenyl group for Rx ₁ to Rx ₃ .
Aralkyl groups of Rx ₁ to Rx ₃ are preferably aralkyl groups having 7 to 14 carbon atoms. Moreover, the aralkyl group may have a substituent.
Aralkyl groups having 7 to 14 carbon atoms include, for example, benzyl, phenethyl, naphthylmethyl, naphthylethyl and naphthylbutyl groups.

When two of Rx ₁ to Rx ₃ combine to form a ring, the formed ring may be monocyclic or polycyclic. The ring formed is preferably a cycloalkyl group.
The cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is preferably a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group. Polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group are also preferred. Among them, monocyclic cycloalkyl groups having 5 to 6 carbon atoms are preferred.
A cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is, for example, a group in which one of the methylene groups constituting the ring contains a heteroatom such as an oxygen atom, a heteroatom such as a carbonyl group, or It may be substituted with a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.
In the repeating unit represented by formula (AI), for example, Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are preferably combined to form the above-mentioned cycloalkyl group.

When each of the above groups has a substituent, examples of the substituent include an alkyl group (1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group. (2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.

The repeating unit represented by the formula (AI) includes an acid-decomposable (meth)acrylic acid tertiary alkyl ester-based repeating unit (Xa ₁ represents a hydrogen atom or a methyl group, and T represents a single bond. ) is preferred.

Resin (A) may have a repeating unit having an acid-decomposable group containing an unsaturated bond as the repeating unit having an acid-decomposable group.
As the repeating unit having an acid-decomposable group containing an unsaturated bond, a repeating unit represented by formula (B) is preferable.

In formula (B), Xb represents a hydrogen atom, a halogen atom, or an optionally substituted alkyl group. L represents a single bond or a divalent linking group which may have a substituent. Ry ₁ to Ry ₃ each independently represent a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an alkenyl group, an alkynyl group, or a monocyclic or polycyclic aryl group . However, at least one of Ry ₁ to Ry ₃ represents an alkenyl group, an alkynyl group, a monocyclic or polycyclic cycloalkenyl group, or a monocyclic or polycyclic aryl group.
Two of Ry ₁ to Ry ₃ may combine to form a monocyclic or polycyclic ring (a monocyclic or polycyclic cycloalkyl group, cycloalkenyl group, etc.).

The optionally substituted alkyl group represented by Xb includes, for example, a methyl group and a group represented by —CH ₂ —R ₁₁ . R ₁₁ represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, for example, an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, preferably an alkyl group having 3 or less carbon atoms, and more preferably a methyl group. Xb is preferably a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

The divalent linking group of L includes -Rt- group, -CO- group, -COO-Rt- group, -COO-Rt-CO- group, -Rt-CO- group, and -O-Rt- groups. In the formula, Rt represents an alkylene group, a cycloalkylene group, or an aromatic ring group, preferably an aromatic ring group.
L is preferably -Rt-, -CO-, -COO-Rt-CO- or -Rt-CO-. Rt may have substituents such as halogen atoms, hydroxyl groups, and alkoxy groups.

The alkyl groups represented by Ry ₁ to Ry ₃ include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. preferable.
Cycloalkyl groups represented by Ry ₁ to Ry ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group and adamantyl group. Polycyclic cycloalkyl groups are preferred.
The aryl group represented by Ry ₁ to Ry ₃ is preferably an aryl group having 6 to 10 carbon atoms, such as phenyl group, naphthyl group and anthryl group.
A vinyl group is preferable as the alkenyl group for Ry ₁ to Ry ₃ .
An ethynyl group is preferred as the alkynyl group for Ry ₁ to Ry ₃ .
Cycloalkenyl groups represented by Ry ₁ to Ry ₃ are preferably monocyclic cycloalkyl groups such as cyclopentyl groups and cyclohexyl groups, which partially contain a double bond.
The cycloalkyl group formed by combining two of Ry ₁ to Ry ₃ includes a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, and a tetracyclododeca. Polycyclic cycloalkyl groups such as a nyl group and an adamantyl group are preferred. Among them, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferable.
A cycloalkyl group formed by combining two of Ry ₁ to Ry ₃ or a cycloalkenyl group, for example, one of the methylene groups constituting the ring is a hetero atom such as an oxygen atom, a carbonyl group, or —SO ₂ It may be substituted with a group containing a heteroatom such as a - group and a -SO ₃ - group, a vinylidene group, or a combination thereof. In these cycloalkyl groups or cycloalkenyl groups, one or more ethylene groups constituting the cycloalkane ring or cycloalkene ring may be replaced with a vinylene group.
In the repeating unit represented by formula (B), for example, Ry ₁ is a methyl group, an ethyl group, a vinyl group, an allyl group, or an aryl group, and Ry ₂ and Ry ₃ combine to form the above-mentioned cycloalkyl A preferred embodiment forms a group or a cycloalkenyl group.

The repeating unit represented by the formula (B) is preferably an acid-decomposable (meth)acrylic acid tertiary ester-based repeating unit (Xb represents a hydrogen atom or a methyl group, and L represents a —CO— group. repeating unit represented), acid-decomposable hydroxystyrene tertiary alkyl ether-based repeating unit (repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a phenyl group), acid-decomposable styrene carboxylic acid tertiary ester It is a repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a -Rt-CO- group (Rt is an aromatic group)).

The content of the repeating unit having an acid-decomposable group containing an unsaturated bond is preferably 15 mol% or more, more preferably 20 mol% or more, and 30 mol% or more, based on the total repeating units in the resin (A). is more preferred. Moreover, the upper limit thereof is preferably 80 mol % or less, more preferably 70 mol % or less, and even more preferably 60 mol % or less, based on all repeating units in the resin (A).

Specific examples of repeating units having an acid-decomposable group containing an unsaturated bond are shown below, but are not limited thereto. In the formula, Xb and L ₁ represent any of the substituents and linking groups described above, Ar represents an aromatic group, and R represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group. , an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR''' or -COOR''', R''' having 1 to 20 carbon atoms an alkyl group or a fluorinated alkyl group), or a substituent such as a carboxyl group; Alternatively, a monocyclic or polycyclic aryl group is represented, and Q is a heteroatom such as an oxygen atom, a carbonyl group, a heteroatom-containing group such as a —SO ₂ — group and a —SO ₃ — group, a vinylidene group, or any of these represents a combination, and n, m and l represent integers of 0 or more.

The resin (A) is a group consisting of a repeating unit represented by the following general formula (A1), a repeating unit represented by the following general formula (A2), and a repeating unit represented by the following general formula (A3). It is preferable to have at least one more selected.

In general formula (A1),
R ^a1 , R ^a2 and R ^a3 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
L ^a1 represents a single bond or a divalent linking group.
Ar ^a1 represents an aromatic ring group.
R ^a4 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
R ^a5 and R ^a6 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
R ^a4 and R ^a5 may combine with each other to form a ring. Ar ^a1 may combine with R ^a3 or R ^a4 to form a ring.

In general formula (A2),
R ^a7 , R ^a8 and R ^a9 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
^La2 represents a single bond or a divalent linking group.
Ar ^a2 represents an aromatic ring group.
R ^a10 , R ^a11 and R ^a12 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group. Two of R ^a10 , R ^a11 and R ^a12 may combine with each other to form a ring.

In the general formula (A3),
R ^a13 , R ^a14 and R ^a15 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
^La3 represents a single bond or a divalent linking group.
Ar ^a3 represents an aromatic ring group.
R ^a16 , R ^a17 and R ^a18 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group. Two of R ^a16 , R ^a17 and R ^a18 may combine with each other to form a ring.

The alkyl groups of R ^a1 , R ^a2 and R ^a3 may be linear or branched. Moreover, the said alkyl group may have a substituent. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group.

The cycloalkyl groups of R ^a1 , R ^a2 and R ^a3 may be monocyclic cycloalkyl groups or polycyclic cycloalkyl groups. Moreover, the cycloalkyl group may have a substituent. Cycloalkyl groups of Rx ₁ to Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. is preferred. In the cycloalkyl group, for example, one of the ring-constituting methylene groups may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a heteroatom-containing group such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

The alkyl groups in the alkoxycarbonyl groups of R ^a1 , R ^a2 and R ^a3 may be linear or branched. Moreover, the said alkyl group may have a substituent. The alkyl group in the alkoxycarbonyl group is preferably an alkyl group having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group.

Examples of the divalent linking group for L ^a1 include an alkylene group, —COO—, and —COO—Rt— group. In the formula, Rt represents an alkylene group or a cycloalkylene group.
L ^a1 is preferably a single bond or -COO-.
Examples of the aromatic ring group for Ar ^a1 include aromatic ring groups having 6 to 15 carbon atoms. Examples of the aromatic ring constituting the aromatic ring group include a benzene ring and a naphthalene ring, with a benzene ring being preferred. The aromatic ring group may have a substituent.

The alkyl groups of R ^a4 to R ^a6 may be linear or branched. Moreover, the said alkyl group may have a substituent. The alkyl groups of R ^a4 to R ^a6 include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. preferable.
The cycloalkyl groups of R ^a4 to R ^a6 may be monocyclic cycloalkyl groups or polycyclic cycloalkyl groups. Moreover, the cycloalkyl group may have a substituent. Cycloalkyl groups of R ^a4 to R ^a6 include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. is preferred. In the cycloalkyl group, for example, one of the ring-constituting methylene groups may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a heteroatom-containing group such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

The aryl groups of R ^a4 to R ^a6 may be monocyclic aryl groups or polycyclic aryl groups. Moreover, the aryl group may have a substituent. The aryl group represented by R ^a4 to R ^a6 is preferably an aryl group having 6 to 10 carbon atoms, such as phenyl group, naphthyl group and anthryl group.
Aralkyl groups of R ^a4 to R ^a6 are preferably aralkyl groups having 7 to 14 carbon atoms. Moreover, the aralkyl group may have a substituent.
Aralkyl groups having 7 to 14 carbon atoms include, for example, benzyl, phenethyl, naphthylmethyl, naphthylethyl and naphthylbutyl groups.
The alkenyl groups of R ^a4 to R ^a6 may be linear or branched. Moreover, the said alkenyl group may have a substituent. A vinyl group is preferable as the alkenyl group of R ^a4 to R ^a6 .

R ^a4 and R ^a5 may combine with each other to form a ring. Ar ^a1 may combine with R ^a3 or R ^a4 to form a ring.
When R ^a4 and R ^a5 combine to form a ring, the ring formed may be monocyclic or polycyclic. The ring formed is preferably a cycloalkyl group.

Examples of the alkyl groups for R ^a7 , R ^a8 and R ^a9 include the same alkyl groups as those for R ^a1 , R ^a2 and R ^a3 , and the preferred ranges are also the same.
As the cycloalkyl groups for R ^a7 , R ^a8 and R ^a9 , the same cycloalkyl groups as those for R ^a1 , R ^a2 and R ^a3 can be mentioned, and the preferred ranges are also the same.
The cycloalkyl groups for R ^a7 , R ^a8 and R ^a9 include monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, norbornyl, tetracyclodecanyl, tetracyclododecanyl, and A polycyclic cycloalkyl group such as an adamantyl group is preferred. In the cycloalkyl group, for example, one of the ring-constituting methylene groups may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a heteroatom-containing group such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

Examples of the aryl groups for R ^a7 , R ^a8 and R ^a9 include the same aryl groups as those for R ^a1 , R ^a2 and R ^a3 , and the preferred ranges are also the same.
Examples of the alkyl groups in the alkoxycarbonyl groups of R ^a7 , R ^a8 and R ^a9 include the same alkyl groups as the alkyl groups in the alkoxycarbonyl groups of R ^a1 , R ^a2 and R ^a3 , and the preferred ranges are also the same.

The divalent linking group for L ^a2 includes an alkylene group, —COO—, and —COO—Rt— group. In the formula, Rt represents an alkylene group or a cycloalkylene group.
L ^a2 is preferably a single bond or -COO-.
Examples of the aromatic ring group for Ar ^a2 include aromatic ring groups having 6 to 15 carbon atoms. Examples of the aromatic ring constituting the aromatic ring group include a benzene ring and a naphthalene ring, with a benzene ring being preferred. The aromatic ring group may have a substituent.

Examples of the alkyl groups for R ^a10 , R ^a11 and R ^a12 include the same alkyl groups as those for R ^a4 , R ^a5 and R ^a6 , and the preferred ranges are also the same.
As the cycloalkyl groups for R ^a10 , R ^a11 and R ^a12 , the same cycloalkyl groups as those for R ^a4 , R ^a5 and R ^a6 can be mentioned, and the preferred ranges are also the same. The cycloalkyl groups for R ^a10 , R ^a11 and R ^a12 include monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl, norbornyl, tetracyclodecanyl, tetracyclododecanyl, and A polycyclic cycloalkyl group such as an adamantyl group is preferred. In the cycloalkyl group, for example, one of the ring-constituting methylene groups may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a heteroatom-containing group such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

Examples of the aryl groups for R ^a10 , R ^a11 and R ^a12 include the same aryl groups as those for R ^a4 , R ^a5 and R ^a6 , and the preferred ranges are also the same.
Examples of the aralkyl groups for R ^a10 , R ^a11 and R ^a12 include the same aralkyl groups as the aralkyl groups for R ^a4 , R ^a5 and R ^a6 , and the preferred ranges are also the same.
Examples of the alkenyl groups for R ^a10 , R ^a11 and R ^a12 include the same alkenyl groups as the alkenyl groups for R ^a4 , R ^a5 and R ^a6 , and the preferred ranges are also the same.

Two of R ^a10 , R ^a11 and R ^a12 may combine with each other to form a ring.
When two of R ^a10 , R ^a11 and R ^a12 combine with each other to form a ring, the formed ring may be monocyclic or polycyclic. The ring formed is preferably a cycloalkyl group.
The cycloalkyl group formed by combining two of R ^a10 , R ^a11 and R ^a12 with each other is preferably a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group. Polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group are also preferred. Among them, monocyclic cycloalkyl groups having 5 to 6 carbon atoms are preferred.
In the cycloalkyl group formed by combining two of R ^a10 , R ^a11 and R ^a12 , for example, one of the methylene groups constituting the ring contains a hetero atom such as an oxygen atom or a hetero atom such as a carbonyl group may be substituted with a group or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

Examples of the alkyl groups for R ^a13 , R ^a14 and R ^a15 include the same alkyl groups as those for R ^a1 , R ^a2 and R ^a3 , and the preferred ranges are also the same.
Examples of the cycloalkyl groups for R ^a13 , R ^a14 and R ^a15 include the same cycloalkyl groups as those for R ^a1 , R ^a2 and R ^a3 , and the preferred ranges are also the same. The cycloalkyl groups of R ^a13 , R ^a14 and R ^a15 include monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, norbornyl, tetracyclodecanyl, tetracyclododecanyl, and A polycyclic cycloalkyl group such as an adamantyl group is preferred. In the cycloalkyl group, for example, one of the ring-constituting methylene groups may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a heteroatom-containing group such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

Examples of the aryl group for R ^a13 , R ^a14 and R ^a15 include the same aryl groups as those for R ^a1 , R ^a2 and R ^a3 , and the preferred ranges are also the same.
Examples of the alkyl groups in the alkoxycarbonyl groups of R ^a13 , R ^a14 and R ^a15 include the same alkyl groups as the alkyl groups in the alkoxycarbonyl groups of R ^a1 , R ^a2 and R ^a3 , and the preferred ranges are also the same.

Examples of the divalent linking group for L ^a3 include an alkylene group, —COO—, and —COO—Rt— group. In the formula, Rt represents an alkylene group or a cycloalkylene group.
L ^a3 is preferably a single bond or -COO-.
Examples of the aromatic ring group for Ar ^a3 include aromatic ring groups having 6 to 15 carbon atoms. Examples of the aromatic ring constituting the aromatic ring group include a benzene ring and a naphthalene ring, with a benzene ring being preferred. The aromatic ring group may have a substituent.

Examples of the alkyl groups for R ^a16 , R ^a17 and R ^a18 include the same alkyl groups as those for R ^a4 , R ^a5 and R ^a6 , and the preferred ranges are also the same.
As the cycloalkyl groups for R ^a16 , R ^a17 and R ^a18 , the same cycloalkyl groups as those for R ^a4 , R ^a5 and R ^a6 can be mentioned, and the preferred ranges are also the same. The cycloalkyl groups for R ^a16 , R ^a17 and R ^a18 include monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, norbornyl, tetracyclodecanyl, tetracyclododecanyl, and A polycyclic cycloalkyl group such as an adamantyl group is preferred. In the cycloalkyl group, for example, one of the ring-constituting methylene groups may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a heteroatom-containing group such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

Examples of the aryl group for R ^a16 , R ^a17 and R ^a18 include the same aryl groups as those for R ^a4 , R ^a5 and R ^a6 , and the preferred ranges are also the same.
Examples of the aralkyl group for R ^a16 , R ^a17 and R ^a18 include the same aralkyl groups as those for R ^a4 , R ^a5 and R ^a6 , and the preferred ranges are also the same.
Examples of the alkenyl groups for R ^a16 , R ^a17 and R ^a18 include the same alkenyl groups as those for R ^a4 , R ^a5 and R ^a6 , and the preferred ranges are also the same.

Two of R ^a16 , R ^a17 and R ^a18 may combine with each other to form a ring.
When two of R ^a16 , R ^a17 and R ^a18 combine with each other to form a ring, the formed ring may be monocyclic or polycyclic. The ring formed is preferably a cycloalkyl group.
The cycloalkyl group formed by combining two of R ^a16 , R ^a17 and R ^a18 with each other is preferably a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group. Polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group are also preferred. Among them, monocyclic cycloalkyl groups having 5 to 6 carbon atoms are preferred.
In the cycloalkyl group formed by bonding two of R ^a16 , R ^a17 and R ^a18 together, for example, one of the methylene groups constituting the ring may be a hetero atom such as an oxygen atom or a hetero atom such as a carbonyl group. containing group or may be substituted with a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

The content of repeating units having an acid-decomposable group is preferably 15 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, relative to all repeating units in the resin (A). The upper limit is preferably 90 mol% or less, more preferably 80 mol% or less, still more preferably 70 mol% or less, and particularly 60 mol% or less, relative to all repeating units in the resin (A). preferable.

The resin (A) may contain at least one repeating unit selected from the group consisting of Group A below and/or at least one repeating unit selected from the group consisting of Group B below. good.
Group A: A group consisting of the following repeating units (20) to (25).
(20) a repeating unit having an acid group, which will be described later; A repeating unit having a lactone group, a sultone group, or a carbonate group (23), a repeating unit having a photoacid-generating group (24), which will be described later, represented by the formula (V-1) or the following formula (V-2) (25) a repeating unit for reducing the mobility of the main chain The repeating units represented by formulas (A) to (E), which will be described later, are (25) reducing the mobility of the main chain corresponds to a repeating unit for
Group B: A group consisting of the following repeating units (30) to (32).
(30) A repeating unit having at least one group selected from a lactone group, a sultone group, a carbonate group, a hydroxyl group, a cyano group, and an alkali-soluble group, which will be described later (31) Having an alicyclic hydrocarbon structure, which will be described later and a repeating unit (32) that does not exhibit acid decomposability, and a repeating unit represented by the formula (III) having neither a hydroxyl group nor a cyano group, which will be described later.

The resin (A) preferably has an acid group, and preferably contains a repeating unit having an acid group, as described later. The definition of the acid group will be explained later along with preferred embodiments of repeating units having an acid group. When the resin (A) has an acid group, the interaction between the resin (A) and the acid generated from the photoacid generator is more excellent. As a result, diffusion of acid is further suppressed, and the cross-sectional shape of the formed pattern can be made more rectangular.

The resin (A) may have at least one type of repeating unit selected from the group consisting of the A group. When the composition of the present invention is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV exposure, the resin (A) has at least one repeating unit selected from the group consisting of Group A above. is preferred.
Resin (A) may contain at least one of a fluorine atom and an iodine atom. When the composition of the present invention is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV exposure, the resin (A) preferably contains at least one of a fluorine atom and an iodine atom. When the resin (A) contains both a fluorine atom and an iodine atom, the resin (A) may have one repeating unit containing both a fluorine atom and an iodine atom, and the resin (A) It may contain two types of a repeating unit containing a fluorine atom and a repeating unit containing an iodine atom.
Resin (A) may have a repeating unit having an aromatic group. When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV exposure, it is also preferred that the resin (A) has a repeating unit having an aromatic group.
The resin (A) may have at least one type of repeating unit selected from the group consisting of Group B above. When the composition of the present invention is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF, the resin (A) may have at least one repeating unit selected from the group consisting of Group B above. preferable.
When the composition of the present invention is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF, the resin (A) preferably contains neither fluorine atoms nor silicon atoms.
When the composition of the present invention is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF, the resin (A) preferably has no aromatic group.

(Repeating unit having an acid group)
Resin (A) may have a repeating unit having an acid group.
As the acid group, an acid group having a pKa of 13 or less is preferable. The acid dissociation constant of the acid group is preferably 13 or less, more preferably 3-13, even more preferably 5-10.
When the resin (A) has an acid group with a pKa of 13 or less, the content of the acid group in the resin (A) is not particularly limited, but is often 0.2 to 6.0 mmol/g. Among them, 0.8 to 6.0 mmol/g is preferable, 1.2 to 5.0 mmol/g is more preferable, and 1.6 to 4.0 mmol/g is even more preferable. If the content of the acid group is within the above range, the development proceeds satisfactorily, the formed pattern shape is excellent, and the resolution is also excellent.
The acid group is preferably, for example, a carboxyl group, a phenolic hydroxyl group, a fluoroalcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group.
In the hexafluoroisopropanol group, one or more (preferably 1 to 2) fluorine atoms may be substituted with a group other than a fluorine atom (such as an alkoxycarbonyl group).
Also preferred as the acid group is -C(CF ₃ )(OH)-CF ₂ - thus formed. Also, one or more of the fluorine atoms may be substituted with a group other than a fluorine atom to form a ring containing -C(CF ₃ )(OH)-CF ₂ -.
The repeating unit having an acid group is different from the repeating unit having a structure in which the polar group is protected by a group that leaves under the action of an acid, and the repeating unit having a lactone group, a sultone group, or a carbonate group, which will be described later. It is preferably a repeating unit.
A repeating unit having an acid group may have a fluorine atom or an iodine atom.

As the repeating unit having an acid group, a repeating unit represented by the following formula (1) is preferable.

In formula (1), A represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, or a cyano group. R represents a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an aralkyl group, an alkoxy group, an alkylcarbonyloxy group, an alkylsulfonyloxy group, an alkyloxycarbonyl group, or an aryloxycarbonyl group; In some cases they may be the same or different. When it has a plurality of R, they may jointly form a ring. A hydrogen atom is preferred as R. a represents an integer of 1 to 3; b represents an integer from 0 to (5-a).

The content of repeating units having an acid group is preferably 10 mol% or more, more preferably 15 mol% or more, relative to all repeating units in the resin (A). Moreover, the upper limit thereof is preferably 70 mol % or less, more preferably 65 mol % or less, and still more preferably 60 mol % or less, based on all repeating units in the resin (A).

(Repeating unit having neither an acid-decomposable group nor an acid group and having a fluorine atom, a bromine atom, or an iodine atom)
The resin (A) has neither an acid-decomposable group nor an acid group, apart from the above-described <repeating unit having an acid-decomposable group> and <repeating unit having an acid group>, and contains a fluorine atom and a bromine atom. Alternatively, it may have a repeating unit having an iodine atom (hereinafter also referred to as unit X). The <repeating unit having neither an acid-decomposable group nor an acid group and having a fluorine atom, a bromine atom, or an iodine atom> referred to here is a <repeating unit having a lactone group, a sultone group, or a carbonate group> described later. , and <repeating unit having photoacid-generating group>.

As the unit X, a repeating unit represented by formula (C) is preferable.

_L5 represents a single bond or an ester group. _R9 represents a hydrogen atom or an alkyl group optionally having a fluorine atom or an iodine atom. R ₁₀ may have a hydrogen atom, an alkyl group optionally having a fluorine atom or an iodine atom, a cycloalkyl group optionally having a fluorine atom or an iodine atom, a fluorine atom or an iodine atom represents an aryl group or a group combining these;

The content of the unit X is preferably 0 mol% or more, more preferably 5 mol% or more, and still more preferably 10 mol% or more, relative to all repeating units in the resin (A). Moreover, the upper limit thereof is preferably 50 mol % or less, more preferably 45 mol % or less, and still more preferably 40 mol % or less, relative to all repeating units in the resin (A).

Among the repeating units of the resin (A), the total content of repeating units containing at least one of a fluorine atom, a bromine atom and an iodine atom is preferably 10 mol% or more with respect to all repeating units of the resin (A). , more preferably 20 mol % or more, still more preferably 30 mol % or more, and particularly preferably 40 mol % or more. Although the upper limit is not particularly limited, it is, for example, 100 mol % or less with respect to all repeating units of the resin (A).
The repeating unit containing at least one of a fluorine atom, a bromine atom and an iodine atom includes, for example, a repeating unit having a fluorine atom, a bromine atom or an iodine atom and having an acid-decomposable group, a fluorine atom, a bromine repeating units having an acid group, and repeating units having a fluorine atom, a bromine atom, or an iodine atom.

(Repeating unit having a lactone group, a sultone group, or a carbonate group)
Resin (A) may have a repeating unit (hereinafter also referred to as “unit Y”) having at least one selected from the group consisting of a lactone group, a sultone group and a carbonate group.
It is also preferable that the unit Y does not have a hydroxyl group and an acid group such as a hexafluoropropanol group.

The lactone group or sultone group may have a lactone structure or sultone structure. The lactone structure or sultone structure is preferably a 5- to 7-membered ring lactone structure or a 5- to 7-membered ring sultone structure. Among them, a 5- to 7-membered ring lactone structure in which a bicyclo structure or spiro structure is formed and another ring structure is condensed with another ring structure, or a 5- to 7-membered ring sultone in a form to form a bicyclo structure or spiro structure. More preferably, the structure is condensed with another ring structure.
The resin (A) has a lactone structure represented by any one of the following formulas (LC1-1) to (LC1-21), or any one of the following formulas (SL1-1) to (SL1-3). It preferably has a repeating unit having a lactone group or a sultone group obtained by removing one or more hydrogen atoms from a ring member atom of a sultone structure, and the lactone group or sultone group may be directly bonded to the main chain. For example, ring member atoms of a lactone group or a sultone group may constitute the main chain of resin (A).

The lactone structure or sultone structure may have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 4 to 7 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkoxycarbonyl groups having 1 to 8 carbon atoms, and carboxyl groups. , halogen atoms, cyano groups, and acid-labile groups. n2 represents an integer of 0-4. When n2 is 2 or more, multiple Rb ₂ may be different, and multiple Rb ₂ may combine to form a ring.

Repeat having a group containing a lactone structure represented by any one of formulas (LC1-1) to (LC1-21) or a sultone structure represented by any one of formulas (SL1-1) to (SL1-3) Examples of units include repeating units represented by the following formula (AI).

In formula (AI), Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferred substituents that the alkyl group of Rb ₀ may have include a hydroxyl group and a halogen atom.
A halogen atom for Rb ₀ includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb ₀ is preferably a hydrogen atom or a methyl group.
Ab is a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a combination of these divalent linkages represents a group. Among them, Ab is preferably a single bond or a linking group represented by -Ab ₁ -CO ₂ -. Ab ₁ is a linear or branched alkylene group or a monocyclic or polycyclic cycloalkylene group, preferably a methylene group, ethylene group, cyclohexylene group, adamantylene group or norbornylene group.
V is a group obtained by removing one hydrogen atom from a ring member atom of a lactone structure represented by any one of formulas (LC1-1) to (LC1-21), or formulas (SL1-1) to (SL1- 3) represents a group obtained by removing one hydrogen atom from a ring member atom of the sultone structure represented by any one of 3).

When an optical isomer exists in the repeating unit having a lactone group or a sultone group, any optical isomer may be used. Moreover, one optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, its optical purity (ee) is preferably 90 or more, more preferably 95 or more.

As the carbonate group, a cyclic carbonate group is preferred.
As the repeating unit having a cyclic carbonate group, a repeating unit represented by the following formula (A-1) is preferable.

In formula (A-1), R _A ¹ represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably a methyl group). n represents an integer of 0 or more. _RA2 represents ^a substituent. When n is 2 or more, a plurality of R _A ² may be the same or different. A represents a single bond or a divalent linking group. The divalent linking group includes an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a combination of these. A valent linking group is preferred. Z represents an atomic group forming a monocyclic or polycyclic ring together with the group represented by -O-CO-O- in the formula.

The content of the unit Y is preferably 1 mol% or more, more preferably 10 mol% or more, relative to all repeating units in the resin (A). The upper limit is preferably 85 mol% or less, more preferably 80 mol% or less, still more preferably 70 mol% or less, and particularly 60 mol% or less, relative to all repeating units in the resin (A). preferable.

(Repeating unit having a photoacid-generating group)
The resin (A) may have, as a repeating unit other than the above, a repeating unit having a group that generates an acid upon exposure to actinic rays or radiation (hereinafter also referred to as a "photoacid-generating group").
The resin (A) preferably has a repeating unit having a group that generates an acid upon exposure to actinic rays or radiation.
Repeating units having a photoacid-generating group include repeating units represented by formula (4).

^R41 represents a hydrogen atom or a methyl group. ^L41 represents a single bond or a divalent linking group. ^L42 represents a divalent linking group. ^R40 represents a structural site that is decomposed by exposure to actinic rays or radiation to generate an acid in the side chain.
Examples of repeating units having a photoacid-generating group are shown below.

In addition, the repeating unit represented by formula (4) includes, for example, repeating units described in paragraphs [0094] to [0105] of JP-A-2014-041327, and International Publication No. 2018/193954. Examples include repeating units described in paragraph [0094].

The content of the repeating unit having a photoacid-generating group is preferably 1 mol % or more, more preferably 5 mol % or more, relative to all repeating units in the resin (A). Moreover, the upper limit thereof is preferably 40 mol % or less, more preferably 35 mol % or less, and still more preferably 30 mol % or less, based on all repeating units in the resin (A).

(Repeating unit represented by formula (V-1) or formula (V-2) below)
Resin (A) may have a repeating unit represented by the following formula (V-1) or the following formula (V-2).
Repeating units represented by the following formulas (V-1) and (V-2) below are preferably different repeating units from the repeating units described above.

During the ceremony,
R ₆ and R ₇ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR or -COOR: R is the number of carbon atoms; 1 to 6 alkyl groups or fluorinated alkyl groups), or a carboxyl group. The alkyl group is preferably a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms.
_n3 represents an integer of 0-6.
_n4 represents an integer of 0-4.
_X4 is a methylene group, an oxygen atom, or a sulfur atom.
The repeating units represented by formula (V-1) or (V-2) are exemplified below.
Examples of the repeating unit represented by formula (V-1) or (V-2) include repeating units described in paragraph [0100] of WO 2018/193954.

(Repeating unit for reducing the mobility of the main chain)
The resin (A) preferably has a high glass transition temperature (Tg) from the viewpoint of suppressing excessive diffusion of generated acid or pattern collapse during development. Tg is preferably greater than 90°C, more preferably greater than 100°C, even more preferably greater than 110°C, and particularly preferably greater than 125°C. The Tg is preferably 400° C. or less, more preferably 350° C. or less, from the viewpoint of excellent dissolution rate in the developer.
In the present specification, the glass transition temperature (Tg) of a polymer such as resin (A) (hereinafter "Tg of repeating unit") is calculated by the following method. First, the Tg of a homopolymer consisting only of each repeating unit contained in the polymer is calculated by the Bicerano method. Next, the mass ratio (%) of each repeating unit to all repeating units in the polymer is calculated. Next, the Fox formula (described in Materials Letters 62 (2008) 3152, etc.) is used to calculate the Tg at each mass ratio, and these are totaled to obtain the Tg (°C) of the polymer.
The Bicerano method is described in Prediction of polymer properties, Marcel Dekker Inc, New York (1993). Calculation of Tg by the Bicerano method can be performed using a polymer physical property estimation software MDL Polymer (MDL Information Systems, Inc.).

In order to increase the Tg of the resin (A) (preferably to make the Tg higher than 90°C), it is preferable to reduce the mobility of the main chain of the resin (A). Methods for reducing the mobility of the main chain of the resin (A) include the following methods (a) to (e).
(a) introduction of bulky substituents into the main chain (b) introduction of multiple substituents into the main chain (c) introduction of substituents that induce interaction between the resin (A) into the vicinity of the main chain ( d) Main Chain Formation in Cyclic Structure (e) Linking of Cyclic Structure to Main Chain The resin (A) preferably has a repeating unit exhibiting a homopolymer Tg of 130° C. or higher.
The type of repeating unit exhibiting a homopolymer Tg of 130° C. or higher is not particularly limited as long as it is a repeating unit having a homopolymer Tg of 130° C. or higher as calculated by the Bicerano method. Depending on the type of functional group in the repeating units represented by the formulas (A) to (E) described below, the homopolymers correspond to repeating units exhibiting a homopolymer Tg of 130° C. or higher.

A specific example of means for achieving the above (a) is a method of introducing a repeating unit represented by the formula (A) into the resin (A).

Formula (A), _RA represents a group containing a polycyclic structure. R _x represents a hydrogen atom, a methyl group, or an ethyl group. A group containing a polycyclic structure is a group containing multiple ring structures, and the multiple ring structures may or may not be condensed.
Specific examples of the repeating unit represented by formula (A) include those described in paragraphs [0107] to [0119] of WO2018/193954.

A specific example of means for achieving the above (b) is a method of introducing a repeating unit represented by the formula (B) into the resin (A).

In formula (B), R _b1 to R _b4 each independently represent a hydrogen atom or an organic group, and at least two or more of R _b1 to R _b4 represent an organic group.
When at least one of the organic groups is a group in which a ring structure is directly linked to the main chain in the repeating unit, the type of other organic group is not particularly limited.
Further, when none of the organic groups is a group in which the ring structure is directly linked to the main chain in the repeating unit, at least two of the organic groups have three or more constituent atoms excluding hydrogen atoms. is a substituent.
Specific examples of the repeating unit represented by formula (B) include those described in paragraphs [0113] to [0115] of WO2018/193954.

A specific example of means for achieving the above (c) is a method of introducing a repeating unit represented by the formula (C) into the resin (A).

In formula (C), R _c1 to R _c4 each independently represent a hydrogen atom or an organic group, and at least one of R _c1 to R _c4 is hydrogen bonding hydrogen within 3 atoms from the main chain carbon It is a group containing atoms. Above all, it is preferable to have a hydrogen-bonding hydrogen atom within 2 atoms (closer to the main chain side) in order to induce interaction between the main chains of the resin (A).
Specific examples of the repeating unit represented by formula (C) include those described in paragraphs [0119] to [0121] of WO2018/193954.

A specific example of means for achieving (d) above is a method of introducing a repeating unit represented by the formula (D) into the resin (A).

In formula (D), "Cyclic" represents a group forming a main chain with a cyclic structure. The number of constituent atoms of the ring is not particularly limited.
Specific examples of the repeating unit represented by formula (D) include those described in paragraphs [0126] to [0127] of WO2018/193954.

A specific example of means for achieving (e) above is a method of introducing a repeating unit represented by formula (E) into the resin (A).

In formula (E), each Re independently represents a hydrogen atom or an organic group. Examples of organic groups include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, and alkenyl groups, which may have substituents.
A "Cyclic" is a cyclic group containing carbon atoms in the main chain. The number of atoms contained in the cyclic group is not particularly limited.
Specific examples of the repeating unit represented by formula (E) include those described in paragraphs [0131] to [0133] of WO2018/193954.

(Repeating unit having at least one group selected from lactone group, sultone group, carbonate group, hydroxyl group, cyano group, and alkali-soluble group)
The resin (A) may have repeating units having at least one group selected from lactone groups, sultone groups, carbonate groups, hydroxyl groups, cyano groups, and alkali-soluble groups.
Examples of the repeating unit having a lactone group, a sultone group, or a carbonate group that the resin (A) has include the repeating units described in the above <Repeating unit having a lactone group, sultone group, or carbonate group>. The preferable content is also as described in <Repeating unit having lactone group, sultone group, or carbonate group>.

Resin (A) may have a repeating unit having a hydroxyl group or a cyano group. This improves the adhesion to the substrate and the compatibility with the developer.
A repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group.
A repeating unit having a hydroxyl group or a cyano group preferably does not have an acid-decomposable group. Examples of repeating units having a hydroxyl group or a cyano group include those described in paragraphs [0081] to [0084] of JP-A-2014-098921.

Resin (A) may have a repeating unit having an alkali-soluble group.
The alkali-soluble group includes a carboxyl group, a sulfonamide group, a sulfonylimide group, a bissulfonylimide group, and an aliphatic alcohol group substituted with an electron-withdrawing group at the α-position (e.g., hexafluoroisopropanol group). , is preferably a carboxyl group. When the resin (A) contains a repeating unit having an alkali-soluble group, the resolution for contact holes is increased. Repeating units having an alkali-soluble group include those described in paragraphs [0085] and [0086] of JP-A-2014-098921.

(Repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid-decomposability)
Resin (A) may have a repeating unit that has an alicyclic hydrocarbon structure and does not exhibit acid decomposability. This can reduce the elution of low-molecular-weight components from the resist film into the immersion liquid during immersion exposure. Repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposability include, for example, 1-adamantyl (meth)acrylate, diamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate, or cyclohexyl (meth) Examples include repeating units derived from acrylates.

(Repeating unit represented by formula (III) having neither hydroxyl group nor cyano group)
Resin (A) may have a repeating unit represented by formula (III) that has neither a hydroxyl group nor a cyano group.

In formula (III), _R5 represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Ra represents a hydrogen atom, an alkyl group or a --CH ₂ --O--Ra ₂ group. In the formula, _Ra2 represents a hydrogen atom, an alkyl group or an acyl group.
Examples of the repeating unit represented by formula (III) having neither a hydroxyl group nor a cyano group include those described in paragraphs [0087] to [0094] of JP-A-2014-098921.

(Other repeating units)
Furthermore, the resin (A) may have repeating units other than the repeating units described above.
For example, the resin (A) has repeating units selected from the group consisting of repeating units having an oxathian ring group, repeating units having an oxazolone ring group, repeating units having a dioxane ring group, and repeating units having a hydantoin ring group. You may have

In addition to the repeating structural units described above, the resin (A) may contain various repeating structural units for the purpose of adjusting dry etching resistance, suitability for standard developer, substrate adhesion, resist profile, resolution, heat resistance, sensitivity, and the like. may have

As the resin (A), in particular, when the composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF, all of the repeating units are repeating units derived from a compound having an ethylenically unsaturated bond. It is preferably composed of In particular, it is also preferred that all of the repeating units are composed of (meth)acrylate repeating units. When all of the repeating units are composed of (meth)acrylate repeating units, all of the repeating units are methacrylate repeating units, all of the repeating units are acrylate repeating units, and all of the repeating units are methacrylates. It is possible to use either one based on repeating units and acrylate repeating units, and it is preferable that the acrylate repeating units be 50 mol % or less of the total repeating units.

Resin (A) can be synthesized according to a conventional method (for example, radical polymerization).
The weight average molecular weight of the resin (A) is preferably 30,000 or less, more preferably 1,000 to 30,000, still more preferably 3,000 to 30,000, further preferably 5,000 as a polystyrene equivalent value by GPC method. ~15,000 is particularly preferred.
The dispersity (molecular weight distribution) of the resin (A) is preferably 1 to 5, more preferably 1 to 3, still more preferably 1.2 to 3.0, and particularly preferably 1.2 to 2.0. The smaller the degree of dispersion, the better the resolution and resist shape, the smoother the side walls of the resist pattern, and the better the roughness.

In the composition of the present invention, the content of the resin (A) is preferably 40.0 to 99.9% by mass, more preferably 60.0 to 90.0% by mass, based on the total solid content of the composition. .
The resin (A) may be used singly or in combination.

<(C) compound>
The composition of the present invention is a compound that generates an acid upon irradiation with actinic rays or radiation, and is an ionic compound having an anion represented by the following general formula (I) (hereinafter referred to as "compound (C)", or Also referred to as "ionic compound (C)").

The divalent linking group for L ¹ is not particularly limited, but examples include an alkylene group, an alkenylene group, —O—, —CO—, —COO—, and a group formed by combining two or more of these.
The alkylene group may be linear or branched. Examples of the alkylene group include those having 1 to 10 carbon atoms.
The alkenylene group may be linear or branched. The alkenylene group includes an alkylene group having 1 to 15 carbon atoms. As the alkenylene group, an alkenylene group having 1 to 10 carbon atoms is preferred.
The alkylene group and alkenylene group may further have a substituent.

The hydrocarbon ring as W may be monocyclic or polycyclic. The hydrocarbon ring is not particularly limited as long as it is a ring composed of hydrocarbon, and examples thereof include hydrocarbon rings having 6 to 20 carbon atoms.
Specific examples include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, naphthacene ring, pyrene ring, cyclohexene ring, and the like.
In addition to these, an acenaphthylene ring can also be mentioned.
The above hydrocarbon ring may be an aromatic ring or a non-aromatic ring. The aromatic ring may be monocyclic or polycyclic. Examples of aromatic rings include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, naphthacene ring, pyrene ring, and acenaphthylene ring.

A heterocyclic ring as W may be monocyclic or polycyclic.
The heterocyclic ring is not particularly limited, and may be an aromatic heterocyclic ring or a non-aromatic heterocyclic ring.
The heterocyclic ring is not particularly limited, but includes, for example, a heterocyclic ring having 3 to 20 carbon atoms.
As a preferred embodiment, the heterocyclic ring as W is preferably a heterocyclic ring represented below. Note that the structure on the left below is tetrathiafulvalene.

Each of the hydrocarbon ring and heterocyclic ring of W may independently have one or more substituents.
The substituent is not particularly limited as long as it is a monovalent substituent, and examples thereof include an alkyl group, an alkoxy group, an aryl group, an aromatic heterocyclic group, an aryloxy group, an alkylthio group, an arylthio group, a hydroxy group, a carboxy, and the like. can be mentioned.
Alkyl groups may be linear or branched. Examples of alkyl groups include alkyl groups having 1 to 10 carbon atoms.
The alkyl group in the alkoxy group may be linear or branched. Examples of the alkyl group in the alkoxy group include alkyl groups having 1 to 10 carbon atoms.
The aryl group may be a monocyclic aryl group or a polycyclic aryl group. Examples of aryl groups include aryl groups having 6 to 10 carbon atoms.
The aromatic heterocyclic group may be a monocyclic aromatic heterocyclic group or a polycyclic aromatic heterocyclic group. The aromatic heterocyclic ring constituting the aromatic heterocyclic group is preferably an aromatic heterocyclic ring having 3 to 10 carbon atoms, such as thiophene.
The aryl group in the aryloxy group may be a monocyclic aryl group or a polycyclic aryl group. Examples of the aryl group in the aryloxy group include aryl groups having 6 to 10 carbon atoms.
The alkyl group in the alkylthio group may be linear or branched. Examples of the alkyl group in the alkylthio group include alkyl groups having 1 to 10 carbon atoms.
The aryl group in the arylthio group may be a monocyclic aryl group or a polycyclic aryl group. Examples of the aryl group in the arylthio group include aryl groups having 6 to 10 carbon atoms.

When each of the hydrocarbon ring and heterocyclic ring of W independently has two or more substituents, the two or more substituents may be the same or different.
In the hydrocarbon ring of W, two or more substituents may combine with each other to form a ring.
In addition, in the heterocyclic ring of W, two or more substituents may combine with each other to form a ring.

The ionic compound (C) is a compound having an anion portion and a cation portion, and is an ionic compound in which the anion portion is an anion represented by the general formula (I).
The cation moiety is not particularly limited, but organic cations can be mentioned.
The cation moiety of the ionic compound (C) is preferably a sulfonium cation or an iodonium cation.
Examples of the cation portion of the ionic compound (C) include the organic cation M ^{2 +} in the photoacid generator (B) described below.
The ionic compound (C) is typically an onium salt such as a sulfonium salt and an iodonium salt.

The ionic compound (C) has an acid HOMO of −6.50 eV or more generated upon exposure to actinic rays or radiation. As described above, by setting the HOMO of the generated acid to −6.50 eV or more, excellent roughness performance can be achieved in ultrafine pattern formation.
The above HOMO represents the energy value of the highest occupied orbital of the acid generated from the compound (C) by irradiation with actinic rays or radiation.
The HOMO value of each compound is calculated using the currently widely used quantum chemical calculation program Gaussian09 Revision A.M. 02, calculated by the density functional theory. B3LYP was used as the functional. A basis function of 6-31+G(d, p) was used.
In addition, according to this method, the LUMO value was calculated for the structure with the minimum formation energy by performing the structure optimization calculation.

HOMO is −6.50 ev or more, preferably −6.30 ev or more, more preferably −6.10 ev or more.
Although the upper limit of HOMO is not particularly limited, it is usually −4.00 ev.
As a preferred embodiment, the HOMO is preferably −6.50 ev or more and −4.00 ev or less, more preferably −6.30 ev or more and −4.00 ev or less, and −6.10 ev or more and −4.00 ev or less. is more preferable.

The anion moiety represented by the above general formula (I) preferably does not correspond to the following (1) and (2), whereby after storing the actinic ray-sensitive or radiation-sensitive resin composition over time, the pattern Roughness performance (hereinbelow, roughness performance in this case is also referred to as "roughness performance after aging") can be greatly improved even when forming is performed.
(1) Ring W has one or more selected from the group consisting of —OH, —COO ^— and —COOH as ring members adjacent to the carbon atom bonded to —L ¹ C(=O)O ^— (2) ring W has, as a ring member, -L ¹ C(=O)O ^- in addition to the carbon atoms bonded to -, one or more carbon atoms, and the ring When W has two or more groups selected from the group consisting of —OH and —COO ^— and —COOH via the one or more carbon atoms as the ring members

As in (1) above, ring W is selected from the group consisting of OH, COOH, or COO- as the ring member adjacent to the carbon atom bonded to -L ¹ C(=O ⁾ O- does not have a ^carbon atom bonded to a group ^having more than In addition, it has one or more carbon atoms, and ring W is selected from the group consisting of -OH and -COO ^- and -COOH via the one or more carbon atoms as the ring members By not having two or more groups, aggregation of the ionic compound (C) can be avoided during storage of the actinic ray-sensitive or radiation-sensitive composition. It is considered that the roughness performance is also excellent.

A carbon atom bonded to a group having at least one selected from the group consisting of —OH and —COO ^— and —COOH as a ring member adjacent to the carbon atom bonded to —L ¹ C(=O)O ^— Specifically, corresponds to C ₁ in the following general formula (X) or C ₂ and C ₃ in the following general formula (Y).

In general formula (X), C ₁ represents a carbon atom and X ₁ represents an atom other than a carbon atom. W and _L1 are the same as W and _L1 in the general formula (I).
In general formula (Y), _C2 and _C3 represent carbon atoms. W and _L1 are the same as W and _L1 in the general formula (I).

In (2) above, the "one or more carbon atoms" as ring members other than the carbon atoms bonded to -L ¹ C(=O ⁾ O- may, for example, satisfy (A) and (B) below. Aspects are included.
(A) "one or more carbon atoms" as the ring member, one carbon atom bonded to a group having two or more groups selected from the group consisting of -OH and -COO ^- and -COOH if it contains .
(B) the "one or more carbon atoms" as the ring members are -OH and -COO ^- and -COOH one carbon atom bonded to a group having one group selected from the group consisting of When including multiple items.

The anion moiety is preferably an anion represented by general formula (I)-1.

Substituents for R ¹ and R ² are not particularly limited, but include alkyl groups, alkoxy groups, alkylthio groups, and the like.
Alkyl groups may be linear or branched. Examples of alkyl groups include alkyl groups having 1 to 10 carbon atoms.
The alkyl group in the alkoxy group may be linear or branched. Examples of the alkyl group in the alkoxy group include alkyl groups having 1 to 10 carbon atoms.
The alkyl group in the alkylthio group may be linear or branched. Examples of the alkyl group in the alkylthio group include alkyl groups having 1 to 10 carbon atoms.
The above alkyl group, alkoxy group, alkylthio group and the like may further have a substituent.
R ¹ is preferably a hydrogen atom. Also, R ² is preferably a hydrogen atom.

The substituent of ^R3 is not particularly limited, but examples thereof include an alkyl group, an alkoxy group, an alkylthio group and the like.
Alkyl groups may be linear or branched. Examples of alkyl groups include alkyl groups having 1 to 10 carbon atoms.
The alkyl group in the alkoxy group may be linear or branched. Examples of the alkyl group in the alkoxy group include alkyl groups having 1 to 10 carbon atoms.
The alkyl group in the alkylthio group may be linear or branched. Examples of the alkyl group in the alkylthio group include alkyl groups having 1 to 10 carbon atoms.
The above alkyl group, alkoxy group, alkylthio group and the like may further have a substituent. The substituent is not particularly limited.
^R3 is preferably a hydrogen atom.

The divalent linking group for L ² is not particularly limited, but may include an alkylene group, an alkenylene group, —O—, —CO—, —COO—, and a group formed by combining two or more of these.
The alkylene group may be linear or branched. Examples of the alkylene group include those having 1 to 10 carbon atoms.
The alkenylene group may be linear or branched. The alkenylene group includes an alkylene group having 1 to 15 carbon atoms. As the alkenylene group, an alkenylene group having 1 to 10 carbon atoms is preferred.
The alkylene group and alkenylene group may further have a substituent.

R ¹ and R ² may combine with each other to form a ring. Although the ring formed by combining R ¹ and R ² is not particularly limited, it is preferably a 6- to 10-membered ring.
R ³ and L ² may combine with each other to form a ring. Although the ring formed by combining R ³ and L ² is not particularly limited, it is preferably a 6- to 10-membered ring.

Further, the anion portion is preferably an anion represented by general formula (I)-2.

In general formula (I)-2,
R ⁴ and R ⁵ each independently represent a hydrogen atom or a substituent other than OH, COO ⁻ and COOH.
R ⁶ to R ⁸ each independently represent a hydrogen atom or a substituent. Two or more of R ⁴ to R ⁸ may combine with each other to form a ring.

The substituents of R ⁴ and R ⁵ are not particularly limited as long as they are substituents other than OH, COO ⁻ and COOH. groups, arylthio groups, and the like.
Alkyl groups may be linear or branched. Examples of alkyl groups include alkyl groups having 1 to 10 carbon atoms.
An alkenyl group may be linear or branched. Alkenyl groups include, for example, alkenyl groups having 2 to 10 carbon atoms.
The alkyl group in the alkoxy group may be linear or branched. Examples of the alkyl group in the alkoxy group include alkyl groups having 1 to 10 carbon atoms.
The aryl group may be a monocyclic aryl group or a polycyclic aryl group. Examples of aryl groups include aryl groups having 6 to 10 carbon atoms.
The aromatic heterocyclic group may be a monocyclic aromatic heterocyclic group or a polycyclic aromatic heterocyclic group. The aromatic heterocyclic ring constituting the aromatic heterocyclic group is preferably an aromatic heterocyclic ring having 3 to 10 carbon atoms, such as thiophene.

The aryl group in the aryloxy group may be a monocyclic aryl group or a polycyclic aryl group. Examples of the aryl group in the aryloxy group include aryl groups having 6 to 10 carbon atoms.
The aryl group in the arylthio group may be a monocyclic aryl group or a polycyclic aryl group. Examples of the aryl group in the arylthio group include aryl groups having 6 to 10 carbon atoms.
The alkyl group, alkenyl group, alkoxy group, aryl group, aromatic heterocyclic group, aryloxy group, and arylthio group may further have a substituent. The substituent is not particularly limited as long as it is a group other than OH, COO ⁻ and COOH.
^R4 is preferably a hydrogen atom or an alkoxy group.
^R5 is preferably a hydrogen atom or an alkoxy group.

Substituents for R ⁶ to R ⁸ are not particularly limited, but examples thereof include alkyl groups, alkenyl groups, alkoxy groups, aryl groups, aromatic heterocyclic groups, aryloxy groups, arylthio groups, and hydroxy groups. .
Alkyl groups may be linear or branched. Examples of alkyl groups include alkyl groups having 1 to 10 carbon atoms.
An alkenyl group may be linear or branched. Alkenyl groups include, for example, alkenyl groups having 2 to 10 carbon atoms.
The alkyl group in the alkoxy group may be linear or branched. Examples of the alkyl group in the alkoxy group include alkyl groups having 1 to 10 carbon atoms.
The aryl group may be a monocyclic aryl group or a polycyclic aryl group. Examples of aryl groups include aryl groups having 6 to 10 carbon atoms.
The aromatic heterocyclic group may be a monocyclic aromatic heterocyclic group or a polycyclic aromatic heterocyclic group. The aromatic heterocyclic ring constituting the aromatic heterocyclic group is preferably an aromatic heterocyclic ring having 3 to 10 carbon atoms, such as thiophene.

The aryl group in the aryloxy group may be a monocyclic aryl group or a polycyclic aryl group. Examples of the aryl group in the aryloxy group include aryl groups having 6 to 10 carbon atoms.
The aryl group in the arylthio group may be a monocyclic aryl group or a polycyclic aryl group. Examples of the aryl group in the arylthio group include aryl groups having 6 to 10 carbon atoms.
^R6 is preferably a hydrogen atom, an alkoxy group, an aryl group, or an aromatic heterocyclic group.
^R7 is preferably a hydrogen atom, an alkoxy group, an aryl group, or an aromatic heterocyclic group.
^R8 is preferably a hydrogen atom, an alkoxy group, an aryl group, or an aromatic heterocyclic group.

Two or more of R ⁴ to R ⁸ may combine with each other to form a ring.
A ring formed by combining two or more of R ⁴ to R ⁸ may be monocyclic or polycyclic.
When two or more of R ⁴ to R ⁸ are bonded together to form a ring, examples of the ring to which the COO ^— group is bonded include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, naphthacene ring, or a pyrene ring, etc. In addition to these, an acenaphthylene ring can also be exemplified.
The ring may further have a substituent.

In general formula (I)-2 above, the ring to which the COO ^— group is bonded is a benzene ring as a monocyclic ring, or a benzene ring formed by bonding two or more of R ⁴ to R ⁸ to each other. It is a polycyclic ring containing 6 to 14 carbon atoms, and more preferably 6 to 10 carbon atoms as ring members constituting the ring to which the COO 2 ^— group is bonded.

As a preferred embodiment, substituents other than OH, COO ⁻ , and COOH are preferred as substituents for R ³ in general formula (I)-1 above.
The general formula (I)-1 preferably has at most one group selected from the group consisting of -OH, -COO ^- and -COOH in addition to -L ¹ C(=O)O ^- .
The general formula (I)-2 preferably has at most one group selected from the group consisting of -OH, -COO ^- and -COOH in addition to -C(=O)O ^- .

Specific examples of the ionic compound (C) are shown below, but are not limited thereto. Me represents a methyl group.

The HOMO value of the acid generated from each compound is shown below.

As a preferred embodiment, the ionic compound (C) is a citric acid compound that generally traps acid generated from a photoacid generator or the like during exposure and suppresses the reaction of the acid-decomposable resin in the unexposed area due to excess generated acid. Acts as a char.

The content of the ionic compound (C) is 3.0% by mass or more, preferably 5.0% by mass or more, and 10.0% by mass or more, relative to the total solid content of the composition. is more preferable.
The upper limit of the content of the ionic compound (C) is not particularly limited. It is preferably 20.0% by mass or less, and more preferably 20.0% by mass or less.
The ionic compound (C) may be used alone or in combination of two or more.

<Compound that generates acid upon exposure to actinic rays or radiation>
The composition of the present invention contains a compound (also referred to as a photoacid generator or a photoacid generator (B)) that generates an acid upon exposure to actinic rays or radiation, which is different from the ionic compound (C). good too.
The photoacid generator (B) may be in the form of a low-molecular-weight compound, or may be in the form of being incorporated into a part of a polymer (for example, a resin (A) described below). Moreover, the form of a low-molecular-weight compound and the form incorporated into a part of a polymer (for example, the resin (A) described later) may be used in combination.
When the photoacid generator (B) is in the form of a low-molecular-weight compound, the molecular weight of the photoacid generator is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less. Although the lower limit is not particularly limited, 100 or more is preferable.
When the photoacid generator (B) is in the form of being incorporated into a part of the polymer, it may be incorporated into a part of the resin (A), or may be incorporated into a resin different from the resin (A). good.
In this specification, the photoacid generator (B) is preferably in the form of a low molecular weight compound.

Examples of the photoacid generator (B) include compounds (onium salts) represented by “M ⁺ X ⁻ ”, and compounds that generate an organic acid upon exposure are preferred.
Examples of the organic acid include sulfonic acid (aliphatic sulfonic acid, aromatic sulfonic acid, camphorsulfonic acid, etc.), carboxylic acid (aliphatic carboxylic acid, aromatic carboxylic acid, aralkylcarboxylic acid, etc.), carbonylsulfonylimide, acids, bis(alkylsulfonyl)imidic acids, and tris(alkylsulfonyl)methide acids.

In the compound represented by "M ⁺ X ^- ", M ⁺ represents an organic cation.
There are no particular restrictions on the organic cation. The valence of the organic cation may be 1 or 2 or more.
As the organic cation, a sulfonium cation or an iodonium cation is preferable.
Among them, as the organic cation, a cation represented by the formula (ZaI) (hereinafter also referred to as "cation (ZaI)"), or a cation represented by the formula (ZaII) (hereinafter referred to as "cation (ZaII)" Also called.) is preferable.

In formula (ZaI) above, R ²⁰¹ , R ²⁰² and R ²⁰³ each independently represent an organic group.
The number of carbon atoms in the organic groups for R ²⁰¹ , R ²⁰² and R ²⁰³ is preferably 1-30, more preferably 1-20. Two of R ²⁰¹ to R ²⁰³ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. Examples of the group formed by combining two of R ²⁰¹ to R ²⁰³ include an alkylene group (eg, a butylene group and a pentylene group) and —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —. mentioned.

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

First, the cation (ZaI-1) will be described.
Cation (ZaI-1) is an arylsulfonium cation in which at least one of R ²⁰¹ to R ²⁰³ in formula (ZaI) above is an aryl group.
In the arylsulfonium cation, all of R ₂₀₁ to R ₂₀₃ may be aryl groups, or part of R ₂₀₁ to R ₂₀₃ may be aryl groups and the rest may be alkyl groups or cycloalkyl groups.
One of R ₂₀₁ to R ₂₀₃ is an aryl group, and the remaining two of R ²⁰¹ to R ²⁰³ may combine to form a ring structure, in which an oxygen atom, a sulfur atom and an ester group , an amide group, or a carbonyl group. The group formed by bonding two of R ²⁰¹ to R ²⁰³ includes, for example, one or more methylene groups substituted with an oxygen atom, a sulfur atom, an ester group, an amide group and/or a carbonyl group. alkylene groups (eg, butylene group, pentylene group, and —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —).
Arylsulfonium cations include triarylsulfonium cations, diarylalkylsulfonium cations, aryldialkylsulfonium cations, diarylcycloalkylsulfonium cations, and aryldicycloalkylsulfonium cations.

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

Examples of substituents that the aryl group, alkyl group and cycloalkyl group of R ²⁰¹ to R ²⁰³ may have include an alkyl group (eg, 1 to 15 carbon atoms), a cycloalkyl group (eg, 3 to 3 carbon atoms). 15), aryl groups (eg, 6 to 14 carbon atoms), alkoxy groups (eg, 1 to 15 carbon atoms), cycloalkylalkoxy groups (eg, 1 to 15 carbon atoms), halogen atoms (eg, fluorine and iodine) , hydroxyl group, carboxyl group, ester group, sulfinyl group, sulfonyl group, alkylthio group or phenylthio group.
If possible, the substituent may further have a substituent, and the alkyl group preferably has a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group.
It is also preferable to form an acid-decomposable group by any combination of the above substituents.
The acid-decomposable group is intended to be a group that is decomposed by the action of an acid to generate a polar group, and preferably has a structure in which the polar group is protected by a group that is eliminated by the action of an acid. The polar group and leaving group are as described above.

Next, the cation (ZaI-2) will be explained.
Cation (ZaI-2) is a cation in which R ²⁰¹ to R ²⁰³ in formula (ZaI) each independently represents an organic group having no aromatic ring. Aromatic rings also include aromatic rings containing heteroatoms.
The number of carbon atoms in the organic group having no aromatic ring as R ²⁰¹ to R ²⁰³ is preferably 1-30, more preferably 1-20.
R ²⁰¹ to R ²⁰³ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, and a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, or An alkoxycarbonylmethyl group is more preferred, and a linear or branched 2-oxoalkyl group is even more preferred.

The alkyl groups and cycloalkyl groups of R ²⁰¹ to R ²⁰³ are, for example, linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, , butyl group, and pentyl group), and cycloalkyl groups having 3 to 10 carbon atoms (eg, cyclopentyl group, cyclohexyl group, and norbornyl group).
R ²⁰¹ to R ²⁰³ may be further substituted with a halogen atom, an alkoxy group (eg, 1-5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.
It is also preferred that the substituents of R ²⁰¹ to R ²⁰³ each independently form an acid-decomposable group by any combination of substituents.

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

In formula (ZaI-3b), R _1c to R _5c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkyl represents a carbonyloxy 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 (eg, t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group.
R _x and R _y each independently represent an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.
It is also preferred that the substituents of R _1c to R _7c , R _x and R _y independently form an acid-decomposable group by any combination of substituents.

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 combine with each other to form a ring. The rings may each independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
Examples of the ring include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic hetero rings, and polycyclic condensed rings in which two or more of these rings are combined. The ring includes a 3- to 10-membered ring, preferably a 4- to 8-membered ring, more preferably a 5- or 6-membered ring.

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

R _1c to R _5c , R _6c , R _7c , R _x , R _y , and two or _more of R _1c to R 5c , R _5c and R _6c , R _6c and R _7c , R _5c and R _x , and the ring formed by combining each other with R _x and R _y may have a substituent.

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

In formula (ZaI-4b), l represents an integer of 0-2 and r represents an integer of 0-8.
R ₁₃ is a hydrogen atom, a halogen atom (e.g., fluorine atom, 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 (cycloalkyl may be the group itself, or may be a group partially containing a cycloalkyl group). These groups may have a substituent.
R ₁₄ is a hydroxyl group, a halogen atom (e.g., fluorine atom, 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 cycloalkyl represents a group containing a group (either a cycloalkyl group itself or a group partially containing a cycloalkyl group). These groups may have a substituent. When two or more R ₁₄ are present, each independently represents the above group such as a hydroxyl group.
Each R ₁₅ independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. Two R ₁₅ may be joined together to form a ring. When two R ₁₅ are combined to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom.
In one aspect, two R ₁₅ are alkylene groups, preferably joined together to form a ring structure. The ring formed by combining the alkyl group, the cycloalkyl group, the naphthyl group, and the two R ₁₅ groups may have a substituent.

In formula (ZaI-4b), the alkyl groups of R ₁₃ , R ₁₄ and R ₁₅ may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1-10. The alkyl group is preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like.
It is also preferred that each of the substituents of R ₁₃ to R ₁₅ , R _x and R _y independently forms an acid-decomposable group by any combination of substituents.

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

The aryl group, alkyl group and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ may each independently have a substituent. Examples of substituents that the aryl group, alkyl group and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ may have include an alkyl group (eg, 1 to 15 carbon atoms) and a cycloalkyl group (eg, 3 to 15), aryl groups (eg, 6 to 15 carbon atoms), alkoxy groups (eg, 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups. It is also preferred that the substituents of R ²⁰⁴ and R ²⁰⁵ each independently form an acid-decomposable group by any combination of substituents.

Specific examples of organic cations are shown below, but the present invention is not limited thereto.

In the compound represented by “M ⁺ X ⁻ ”, X ⁻ represents an organic anion.
The organic anion is not particularly limited, and includes organic anions having a valence of 1, 2 or more.
As the organic anion, an anion having a significantly low ability to cause a nucleophilic reaction is preferred, and a non-nucleophilic anion is more preferred.

Examples of non-nucleophilic anions include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, camphorsulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, and aralkyl carboxylic acid anions), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

The aliphatic moiety in the aliphatic sulfonate anion and the aliphatic carboxylate anion may be a linear or branched alkyl group or a cycloalkyl group, and may be a straight chain having 1 to 30 carbon atoms. Alternatively, a branched alkyl group or a cycloalkyl group having 3 to 30 carbon atoms is preferred.
The alkyl group may be, for example, a fluoroalkyl group (which may have a substituent other than a fluorine atom, or may be a perfluoroalkyl group).

The aryl group in the aromatic sulfonate anion and the aromatic carboxylate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.

The alkyl group, cycloalkyl group, and aryl group listed above may have a substituent. The substituents are not particularly limited, but examples include nitro groups, halogen atoms such as fluorine atoms and chlorine atoms, carboxyl groups, hydroxyl groups, amino groups, cyano groups, alkoxy groups (preferably having 1 to 15 carbon atoms), alkyl groups ( preferably 1 to 10 carbon atoms), a cycloalkyl group (preferably 3 to 15 carbon atoms), an aryl group (preferably 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably 2 to 7 carbon atoms), an acyl group ( preferably 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), alkylthio group (preferably 1 to 15 carbon atoms), alkylsulfonyl group (preferably 1 to 15 carbon atoms), alkylimino A sulfonyl group (preferably having 1 to 15 carbon atoms) and an aryloxysulfonyl group (preferably having 6 to 20 carbon atoms) can be mentioned.

As the aralkyl group in the aralkylcarboxylate anion, an aralkyl group having 7 to 14 carbon atoms is preferred.
Aralkyl groups having 7 to 14 carbon atoms include, for example, benzyl, phenethyl, naphthylmethyl, naphthylethyl and naphthylbutyl groups.

　Sulfonylimide anions include, for example, saccharin anions.

As the alkyl group in the bis(alkylsulfonyl)imide anion and the tris(alkylsulfonyl)methide anion, an alkyl group having 1 to 5 carbon atoms is preferable. Examples of substituents of these alkyl groups include halogen atoms, halogen-substituted alkyl groups, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, and cycloalkylaryloxysulfonyl groups. A fluorine atom or an alkyl group substituted with a fluorine atom is preferred.
In addition, the alkyl groups in the bis(alkylsulfonyl)imide anion may combine with each other to form a ring structure. This increases the acid strength.

Other non-nucleophilic anions include, for example, phosphorous fluorides (eg, PF ₆ ⁻ ), boron fluorides (eg, BF ₄ ⁻ ), and antimony fluorides (eg, SbF ₆ ⁻ ).

Examples of non-nucleophilic anions include aliphatic sulfonate anions in which at least the α-position of sulfonic acid is substituted with fluorine atoms, aromatic sulfonate anions in which fluorine atoms or groups having fluorine atoms are substituted, and alkyl groups in which fluorine atoms are present. A bis(alkylsulfonyl)imide anion substituted with or a tris(alkylsulfonyl)methide anion in which an alkyl group is substituted with a fluorine atom is preferred. Among them, perfluoroaliphatic sulfonate anions (preferably having 4 to 8 carbon atoms) or benzenesulfonate anions having a fluorine atom are more preferable, nonafluorobutanesulfonate anions, perfluorooctanesulfonate anions, pentafluoro A benzenesulfonate anion or a 3,5-bis(trifluoromethyl)benzenesulfonate anion is more preferred.

As the non-nucleophilic anion, an anion represented by the following formula (AN1) is also preferable.

In formula (AN1), R ¹ and R ² each independently represent a hydrogen atom or a substituent.
Although the substituent is not particularly limited, a group that is not an electron-withdrawing group is preferred. Examples of groups that are not electron-withdrawing groups include hydrocarbon groups, hydroxyl groups, oxyhydrocarbon groups, oxycarbonyl hydrocarbon groups, amino groups, hydrocarbon-substituted amino groups, and hydrocarbon-substituted amide groups.
Groups that are not electron-withdrawing groups are preferably -R', -OH, -OR', -OCOR', -NH ₂ , -NR' ₂ , -NHR' or -NHCOR' each independently. . R' is a monovalent hydrocarbon group.

Examples of the monovalent hydrocarbon group represented by R' include alkyl groups such as methyl, ethyl, propyl, and butyl; alkenyl groups such as ethenyl, propenyl, and butenyl; ethynyl monovalent linear or branched hydrocarbon groups such as alkynyl groups such as groups, propynyl groups, and butynyl groups; cyclopropyl groups, cyclobutyl groups, cyclopentyl groups, cyclohexyl groups, norbornyl groups, and adamantyl groups Cycloalkyl group; monovalent alicyclic hydrocarbon group such as cycloalkenyl group such as cyclopropenyl group, cyclobutenyl group, cyclopentenyl group, and norbornenyl group; phenyl group, tolyl group, xylyl group, mesityl group, naphthyl group, methyl aryl groups such as naphthyl group, anthryl group and methylanthryl group; monovalent aromatic hydrocarbon groups such as aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group and anthrylmethyl group; mentioned.
Among them, R ¹ and R ² are each independently preferably a hydrocarbon group (preferably a cycloalkyl group) or a hydrogen atom.

L represents a divalent linking group.
When there are multiple L's, each L may be the same or different.
Examples of divalent linking groups include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -S-, -SO-, -SO ₂ -, alkylene groups ( preferably 1 to 6 carbon atoms), a cycloalkylene group (preferably 3 to 15 carbon atoms), an alkenylene group (preferably 2 to 6 carbon atoms), and a divalent linking group combining a plurality of these. . Among them, the divalent linking group includes -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -SO ₂ -, and -O-CO-O-alkylene group- , -COO-alkylene group-, or -CONH-alkylene group- is preferred, and -O-CO-O-, -O-CO-O-alkylene group-, -COO-, -CONH-, -SO ₂ - , or -COO-alkylene group- is more preferable.

As L, for example, a group represented by the following formula (AN1-1) is preferable.
* ^a - (CR ^2a ₂ ) _X - Q- (CR ^2b ₂ ) _Y - * ^b (AN1-1)

In formula (AN1-1), * ^a represents the bonding position with ^R3 in formula (AN1).
* ^b represents the bonding position with -C(R ¹ )(R ² )- in formula (AN1).
X and Y each independently represent an integer of 0-10, preferably an integer of 0-3.
R ^2a and R ^2b each independently represent a hydrogen atom or a substituent.
When multiple R ^2a and R ^2b are present, the multiple R ^2a and R ^2b may be the same or different.
However, when Y is 1 or more, R ^2b in CR ^2b ₂ directly bonded to —C(R ¹ )(R ² )— in formula (AN1) is other than a fluorine atom.
Q is * ^A -O-CO-O-* ^B , * ^A -CO-* ^B , * ^A -CO-O-* ^B , * ^A -O-CO-* ^B , * ^A -O-* ^B , * ^A -S-* ^B or * ^A - _SO2- * ^B .
However, when X + Y in formula (AN1-1) is 1 or more, and both R ^2a and R ^2b in formula (AN1-1) are hydrogen atoms, Q is * ^A —O—CO -O-* ^B , * ^A -CO-* ^B , * ^A -O-CO-* ^B , * ^A -O-* ^B , * ^A -S-* ^B , or * ^A - _SO2- * ^B represents
* ^A represents the bonding position on the R ³ side in formula (AN1), and * ^B represents the bonding position on the —SO ₃ ^— side in formula (AN1).

In formula (AN1), ^R3 represents an organic group.
The organic group is not particularly limited as long as it has 1 or more carbon atoms. branched chain alkyl group) or a cyclic group. The organic group may or may not have a substituent. The organic group may or may not have a heteroatom (oxygen atom, sulfur atom, and/or nitrogen atom, etc.).

Among them, R ³ is preferably an organic group having a cyclic structure. The cyclic structure may be monocyclic or polycyclic, and may have a substituent. The ring in the organic group containing a cyclic structure is preferably directly bonded to L in formula (AN1).
The organic group having a cyclic structure may or may not have a heteroatom (oxygen atom, sulfur atom, and/or nitrogen atom, etc.), for example. Heteroatoms may replace one or more of the carbon atoms that form the ring structure.
The organic group having a cyclic structure is preferably, for example, a hydrocarbon group having a cyclic structure, a lactone ring group, or a sultone ring group. Among them, the organic group having a cyclic structure is preferably a hydrocarbon group having a cyclic structure.
The above hydrocarbon group having a cyclic structure is preferably a monocyclic or polycyclic cycloalkyl group. These groups may have a substituent.
The cycloalkyl group may be monocyclic (such as cyclohexyl group) or polycyclic (such as adamantyl group), and preferably has 5 to 12 carbon atoms.
Examples of the lactone group and sultone group include structures represented by the above formulas (LC1-1) to (LC1-21) and structures represented by formulas (SL1-1) to (SL1-3). , preferably a group obtained by removing one hydrogen atom from a ring member atom constituting a lactone structure or a sultone structure.

The non-nucleophilic anion may be a benzenesulfonate anion, preferably a benzenesulfonate anion substituted with a branched alkyl group or cycloalkyl group.

As the non-nucleophilic anion, an anion represented by the following formula (AN2) is also preferable.

In formula (AN2), o represents an integer of 1-3. p represents an integer from 0 to 10; q represents an integer from 0 to 10;

Xf represents a hydrogen atom, a fluorine atom, an alkyl group substituted with at least one fluorine atom, or an organic group having no fluorine atom. The number of carbon atoms in this alkyl group is preferably 1-10, more preferably 1-4. A perfluoroalkyl group is preferred as the alkyl group substituted with at least one fluorine atom.
Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, more preferably a fluorine atom or CF ₃ , and even more preferably both Xf are fluorine atoms.

^R4 and ^R5 each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom. When multiple R ⁴ and R ⁵ are present, each of R ⁴ and R ⁵ may be the same or different.
The alkyl groups represented by R ⁴ and R ⁵ preferably have 1 to 4 carbon atoms. The above alkyl group may have a substituent. Hydrogen atoms are preferred as R ₄ and R ₅ .

　L represents a divalent linking group. The definition of L is synonymous with L in formula (AN1).

W represents an organic group containing a cyclic structure. Among them, a cyclic organic group is preferable.
Cyclic organic groups include, for example, alicyclic groups, aryl groups, and heterocyclic groups.
The alicyclic group may be monocyclic or polycyclic. Monocyclic alicyclic groups include, for example, monocyclic cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. The polycyclic alicyclic group includes, for example, a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and a polycyclic cycloalkyl group such as an adamantyl group. Among them, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as norbornyl, tricyclodecanyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups, are preferred.

Aryl groups may be monocyclic or polycyclic. Examples of the aryl group include phenyl group, naphthyl group, phenanthryl group, and anthryl group.
A heterocyclic group may be monocyclic or polycyclic. Especially, when it is a polycyclic heterocyclic group, diffusion of acid can be further suppressed. A heterocyclic group may or may not have an aromatic character. Heterocyclic rings having aromaticity include, for example, furan ring, thiophene ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, and pyridine ring. Non-aromatic heterocycles include, for example, a tetrahydropyran ring, a lactone ring, a sultone ring, and a decahydroisoquinoline ring. The heterocyclic ring in the heterocyclic group is preferably a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring.

The cyclic organic group may have a substituent. Examples of the substituents include alkyl groups (either linear or branched, preferably having 1 to 12 carbon atoms), cycloalkyl groups (monocyclic, polycyclic, and spirocyclic). any group, preferably having 3 to 20 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), hydroxyl group, alkoxy group, ester group, amide group, urethane group, ureido group, thioether group, sulfonamide and sulfonate ester groups. In addition, carbonyl carbon may be sufficient as carbon (carbon which contributes to ring formation) which comprises a cyclic|annular organic group.

Examples of anions represented by formula (AN2) include SO ₃ ⁻ —CF ₂ —CH ₂ —OCO-(L) _q′ —W, SO ₃ ⁻ —CF ₂ —CHF—CH ₂ —OCO-(L) _{q '} -W, SO ₃ ^- -CF ₂ -COO-(L) _q' -W, SO ₃ ^- -CF ₂ -CF ₂ _{-CH 2} -CH ₂ -(L) _q -W, or SO ₃ ^- - CF ₂ —CH(CF ₃ )—OCO—(L) _q′ —W is preferred. Here, L, q and W are the same as in formula (AN2). q' represents an integer from 0 to 10;

As the non-nucleophilic anion, an aromatic sulfonate anion represented by the following formula (AN3) is also preferable.

In formula (AN3), Ar represents an aryl group (such as a phenyl group) and may further have a substituent other than the sulfonate anion and -(D-B) group. Substituents which may be further included include, for example, a fluorine atom and a hydroxyl group.
n represents an integer of 0 or more. n is preferably 1 to 4, more preferably 2 to 3, and still more preferably 3.

D represents a single bond or a divalent linking group. Divalent linking groups include ether groups, thioether groups, carbonyl groups, sulfoxide groups, sulfone groups, sulfonate ester groups, ester groups, and groups consisting of combinations of two or more thereof.

B represents a hydrocarbon group.
B is preferably an aliphatic hydrocarbon group, more preferably an isopropyl group, a cyclohexyl group, or an optionally substituted aryl group (such as a tricyclohexylphenyl group).

Disulfonamide anions are also preferred as non-nucleophilic anions.
A disulfonamide anion is, for example, an anion represented by N ⁻ (SO ₂ —R ^q ) ₂ .
Here, R ^q represents an optionally substituted alkyl group, preferably a fluoroalkyl group, more preferably a perfluoroalkyl group. Two R ^q may combine with each other to form a ring. The group formed by bonding two R ^q together is preferably an optionally substituted alkylene group, preferably a fluoroalkylene group, more preferably a perfluoroalkylene group. The alkylene group preferably has 2 to 4 carbon atoms.

Non-nucleophilic anions also include anions represented by the following formulas (d1-1) to (d1-4).

In formula (d1-1), R ⁵¹ represents a hydrocarbon group (eg, an aryl group such as a phenyl group) optionally having a substituent (eg, hydroxyl group).

In formula (d1-2), Z ^2c represents an optionally substituted hydrocarbon group having 1 to 30 carbon atoms (provided that the carbon atom adjacent to S is not substituted with a fluorine atom).
The above hydrocarbon group for Z ^2c may be linear or branched, and may have a cyclic structure. In addition, the carbon atom in the hydrocarbon group (preferably the carbon atom that is a ring member atom when the hydrocarbon group has a cyclic structure) may be carbonyl carbon (--CO--). Examples of the hydrocarbon group include a group having an optionally substituted norbornyl group. A carbon atom forming the norbornyl group may be a carbonyl carbon.
“Z ^2c —SO ₃ ⁻ ” in formula (d1-2) is preferably different from the anions represented by formulas (AN1) to (AN3) above. For example, Z ^2c is preferably other than an aryl group. For example, the α-position and β-position atoms with respect to —SO ₃ ^— in Z ^2c are preferably atoms other than carbon atoms having a fluorine atom as a substituent. For example, in Z ^2c , the α-position atom and/or the β-position atom with respect to —SO ₃ ^— is preferably a ring member atom in a cyclic group.

In formula (d1-3), R ⁵² represents an organic group (preferably a hydrocarbon group having a fluorine atom), Y ³ represents a linear, branched or cyclic alkylene group, an arylene group, or represents a carbonyl group, and Rf represents a hydrocarbon group.

In formula (d1-4), R ⁵³ and R ⁵⁴ each independently represent an organic group (preferably a hydrocarbon group having a fluorine atom). R ⁵³ and R ⁵⁴ may combine with each other to form a ring.

The organic anions may be used singly or in combination of two or more.

The photoacid generator is also preferably at least one selected from the group consisting of compounds (I) to (II).

(Compound (I))
Compound (I) is a compound having one or more structural moieties X shown below and one or more structural moieties Y shown below, wherein the first acidic It is a compound that generates an acid containing a site and a second acidic site described below derived from the structural site Y described below.
Structural site X: Structural site consisting of an anionic site A ₁ ⁻ and a cation site M ₁ ⁺ and forming a first acidic site represented by HA ₁ upon exposure to actinic rays or radiation Structural site Y: anionic site A structural site consisting of A ₂ ^- and a cationic site M ₂ ⁺ and forming a second acidic site represented by HA ₂ upon exposure to actinic rays or radiation. The compound (I) satisfies the following condition I. .

Condition I: A compound PI obtained by replacing the cation site M ₁ ⁺ in the structural site X and the cation site M ₂ ⁺ in the structural site Y in the compound (I) with H ⁺ in the structural site X and an acid dissociation constant a1 derived from the acidic site represented by HA ₁ obtained by replacing the cation site M 1 ⁺ with H ⁺ , and replacing the cation site M ₂ ⁺ in the structural site _Y with H ⁺ It has an acid dissociation constant a2 derived from the acidic site represented by _HA2 , and the acid dissociation constant a2 is greater than the acid dissociation constant a1.

Condition I will be described in more detail below.
When the compound (I) is, for example, an acid-generating compound having one first acidic site derived from the structural site X and one second acidic site derived from the structural site Y , compound PI corresponds to "a compound having HA ₁ and HA ₂ ".
More specifically, the acid dissociation constant a1 and the acid dissociation constant a2 of compound PI are defined as "a compound having A ₁ ^- and HA ₂ " when the acid dissociation constant of compound PI is determined. is the acid dissociation constant a1, and the pKa when the "compound having A ₁ ^- and HA ₂ " becomes the "compound having A ₁ ^- and A ₂ ^- " is the acid dissociation constant a2 be.

When compound (I) is, for example, an acid-generating compound having two first acidic sites derived from the structural site X and one second acidic site derived from the structural site Y , compound PI corresponds to "a compound having two HA ₁ and one HA ₂ ".
When the acid dissociation constant of compound PI is obtained, the acid dissociation constant when compound PI becomes "a compound having one A ₁ ^- , one HA ₁ and one HA ₂ " and "one A ₁ ^- and one HA ₁ and one HA ₂ ” becomes a “compound having two A ₁ ^- and one HA ₂ ” corresponds to the acid dissociation constant a1 described above. . The acid dissociation constant when "a compound having two A ₁ ^- and one HA _{2 -} " becomes "a compound having two A ₁ ^- and A ₂ ^- " corresponds to the acid dissociation constant a2. That is, in the case of the compound PI, when it has a plurality of acid dissociation constants derived from the acidic site represented by HA ₁ obtained by replacing the cation site M ₁ ⁺ in the structural site X with H ⁺ , a plurality of acid dissociation constants The value of the acid dissociation constant a2 is larger than the largest value of a1. The acid dissociation constant when the compound PI becomes "a compound having one A ₁ ^- , one HA ₁ and one HA ₂ " is aa, and "one A ₁ ^- and one HA ₁ and 1 The relationship ^between aa and ab satisfies aa<ab, where ab is the acid dissociation constant when a compound having two _HA2 's becomes _a compound having two A1- and one _HA2 . .

The acid dissociation constant a1 and the acid dissociation constant a2 are determined by the method for measuring the acid dissociation constant described above.
The above compound PI corresponds to an acid generated when compound (I) is irradiated with actinic rays or radiation.
When compound (I) has two or more structural moieties X, the structural moieties X may be the same or different. Two or more of A ₁ ⁻ and two or more of M ₁ ⁺ may be the same or different.
In compound (I), A ₁ ^- and A ₂ ^- , and M ₁ ⁺ and M ₂ ⁺ may be the same or different, but A ₁ ^- and A ₂ ^- are preferably different.

In the compound PI, the difference (absolute value) between the acid dissociation constant a1 (the maximum value when there are multiple acid dissociation constants a1) and the acid dissociation constant a2 is preferably 0.1 or more, and preferably 0.5 or more. More preferably, 1.0 or more is even more preferable. The upper limit of the difference (absolute value) between the acid dissociation constant a1 (the maximum value if there are a plurality of acid dissociation constants a1) and the acid dissociation constant a2 is not particularly limited, but is, for example, 16 or less.

In the compound PI, the acid dissociation constant a2 is preferably 20 or less, more preferably 15 or less. The lower limit of the acid dissociation constant a2 is preferably -4.0 or more.

In the above compound PI, the acid dissociation constant a1 is preferably 2.0 or less, more preferably 0 or less. The lower limit of the acid dissociation constant a1 is preferably −20.0 or more.

The anion site A ₁ ^- and the anion site A ₂ ^- are structural sites containing negatively charged atoms or atomic groups, for example, formulas (AA-1) to (AA-3) and formula (BB -1) to (BB-6).
The anion site A ₁ ^- is preferably one capable of forming an acidic site with a small acid dissociation constant, and more preferably one of the formulas (AA-1) to (AA-3). AA-1) and (AA-3) are more preferred.
Further, the anion site A ₂ ^- is preferably one capable of forming an acidic site with a larger acid dissociation constant than the anion site A ₁ ^- , and is any of the formulas (BB-1) to (BB-6). is more preferred, and either formula (BB-1) or (BB-4) is even more preferred.
In formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6) below, * represents a bonding position.
In formula (AA-2), ^RA represents a monovalent organic group. Although the monovalent organic group represented by ^RA is not particularly limited, examples thereof include a cyano group, a trifluoromethyl group and a methanesulfonyl group.

The cation site M ₁ ⁺ and the cation site M ₂ ⁺ are structural sites containing positively charged atoms or atomic groups, such as monovalent organic cations. Examples of organic cations include organic cations represented by M ⁺ described above.

(Compound (II))
Compound (II) is a compound having two or more of the above structural moieties X and one or more of the following structural moieties Z, wherein the first acidic It is a compound that generates an acid containing two or more sites and the structural site Z described above.
Structural site Z: nonionic site capable of neutralizing acid

The definition of structural site X and the definitions of A ₁ ^- and M ₁ ⁺ in compound (II) are the same as the definitions of structural site X and the definitions of A ₁ ^- and M ₁ ⁺ in compound (I) above. is synonymous with and preferred embodiments are also the same.

HA ₁ obtained by replacing the cation site M ₁ ⁺ in the structural site X with H ⁺ in the compound PII, which is obtained by replacing the cation site M ₁ ⁺ in the structural site X with H ⁺ in the compound (II). The preferred range of the acid dissociation constant a1 derived from the acidic site represented by is the same as the acid dissociation constant a1 in the above compound PI.
In addition, for example, when the compound (II) is a compound that generates an acid having two of the first acidic sites derived from the structural site X and the structural site Z, the compound PII is "two HA ₁ It corresponds to "a compound having When the acid dissociation constant of this compound PII is determined, the acid dissociation constant when the compound PII is "a compound having one A ₁ ^- and one HA ₁ " and "one A ₁ ^- and one HA The acid dissociation constant when the "compound having ₁ " becomes "the compound having two A ₁ ^- " corresponds to the acid dissociation constant a1.

The acid dissociation constant a1 is obtained by the method for measuring the acid dissociation constant described above.
The above compound PII corresponds to an acid generated when compound (II) is irradiated with actinic rays or radiation.
The two or more structural sites X may be the same or different. Two or more of A ₁ ⁻ and two or more of M ₁ ⁺ may be the same or different.

The nonionic site capable of neutralizing the acid in the structural site Z is not particularly limited. For example, a site containing a group capable of electrostatically interacting with protons or a functional group having electrons is preferred.
A group capable of electrostatically interacting with protons or a functional group having electrons is a functional group having a macrocyclic structure such as a cyclic polyether, or a lone pair of electrons that does not contribute to π conjugation. A functional group having a nitrogen atom is included. A nitrogen atom having a lone pair of electrons that does not contribute to π-conjugation is, for example, a nitrogen atom having a partial structure represented by the following formula.

Partial structures of functional groups having electrons or groups capable of electrostatically interacting with protons include, for example, a crown ether structure, an azacrown ether structure, a primary to tertiary amine structure, a pyridine structure, an imidazole structure, and a pyrazine structure. Among them, primary to tertiary amine structures are preferred.

Examples of moieties other than cations that compound (I) and compound (II) may have.

Specific examples of the photoacid generator are shown below, but are not limited to these.

When the composition of the present invention contains a photoacid generator (B), its content is not particularly limited, but is preferably 5.0% by mass or more, and 10.0% by mass, based on the total solid content of the composition. The above is more preferable. The above content is preferably 50.0% by mass or less, more preferably 30.0% by mass or less, and even more preferably 25.0% by mass or less, relative to the total solid content of the resist composition.
The photoacid generator (B) may be used alone or in combination of two or more.

<Acid diffusion control agent (C1)>
The composition of the present invention may contain an acid diffusion controller (hereinafter also referred to as "acid diffusion controller (C1)" or "acid diffusion controller") different from the ionic compound (C).
The acid diffusion control agent (C1) traps the acid generated from the photoacid generator or the like during exposure and acts as a quencher that suppresses the reaction of the acid-decomposable resin in the unexposed area due to excess generated acid.
The type of the acid diffusion controller (C1) is not particularly limited. Examples thereof include compounds (CC) whose ability to control acid diffusion decreases or disappears upon exposure to light or radiation.
As the compound (CC), an onium salt compound (CD), which becomes a relatively weak acid with respect to the photoacid generator, and a basic compound (CE), whose basicity is reduced or lost by irradiation with actinic rays or radiation. mentioned.
Specific examples of the basic compound (CA) include, for example, those described in paragraphs [0132] to [0136] of WO2020/066824, and the basicity is reduced or reduced by exposure to actinic rays or radiation. Specific examples of the disappearing basic compound (CE) include those described in paragraphs [0137] to [0155] of WO 2020/066824, have a nitrogen atom, and are eliminated by the action of an acid. Specific examples of the low-molecular-weight compound having a group (CB) include those described in paragraphs [0156] to [0163] of WO 2020/066824, and basicity is obtained by irradiation with actinic rays or radiation. Specific examples of the basic compound (CE) that decreases or disappears include those described in paragraph [0164] of WO2020/066824.
Specific examples of the onium salt compound (CD), which is a relatively weak acid with respect to the photoacid generator, include those described in paragraphs [0305] to [0314] of International Publication No. 2020/158337. .

In addition to the above, for example, paragraphs [0627] to [0664] of US Patent Application Publication No. 2016/0070167A1, paragraphs [0095] to [0187] of US Patent Application Publication No. 2015/0004544A1, US Patent Application Publication No. 2016/0237190A1 and paragraphs [0259] to [0328] of US Patent Application Publication No. 2016/0274458A1 can be suitably used as acid diffusion control agents.

When the composition of the present invention contains the acid diffusion control agent (C1), the content of the acid diffusion control agent (C1) (if multiple types are present, the total) is, relative to the total solid content of the composition, 0.1 to 15.0% by mass is preferable, and 1.0 to 15.0% by mass is more preferable.
In the composition of the present invention, the acid diffusion controller (C1) may be used singly or in combination of two or more.

<Hydrophobic resin (D)>
The composition of the invention may further comprise a hydrophobic resin different from resin (A).
Hydrophobic resins are preferably designed to be unevenly distributed on the surface of the resist film. may not contribute to
The effects of adding a hydrophobic resin include control of the static and dynamic contact angles of the resist film surface with respect to water, and suppression of outgassing.

From the viewpoint of uneven distribution on the film surface layer, the hydrophobic resin preferably has one or more of a fluorine atom, a silicon atom, and a _CH3 partial structure contained in the side chain portion of the resin. It is more preferable to have The hydrophobic resin preferably has a hydrocarbon group with 5 or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted on the side chain.
Hydrophobic resins include compounds described in paragraphs [0275] to [0279] of WO2020/004306.

When the composition of the present invention contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01 to 20.0% by mass, and 0.1 to 15.0% by mass, based on the total solid content of the composition. % by mass is more preferred.

<Surfactant (E)>
The composition of the invention may contain a surfactant. When a surfactant is contained, it is possible to form a pattern with excellent adhesion and fewer development defects.
The surfactant is preferably a fluorine-based and/or silicon-based surfactant.
Fluorinated and/or silicon-based surfactants include surfactants disclosed in paragraphs [0218] and [0219] of WO2018/193954.

One type of these surfactants may be used alone, or two or more types may be used.

When the composition of the present invention contains a surfactant, the content of the surfactant is preferably 0.0001 to 2.0% by mass, preferably 0.0005 to 1.0%, based on the total solid content of the composition. % by mass is more preferred, and 0.1 to 1.0% by mass is even more preferred.

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

A combination of the above-described solvent and the above-described resin is preferable from the viewpoint of improving the coatability of the resist composition and reducing the number of development defects in the pattern. Since the solvent described above has a good balance of solubility, boiling point, and viscosity of the resin described above, it is possible to suppress unevenness in the thickness of the resist film and generation of deposits during spin coating.
Details of component (M1) and component (M2) are described in paragraphs [0218] to [0226] of WO2020/004306, the contents of which are incorporated herein.

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

The content of the solvent in the composition of the present invention is preferably determined so that the solid content concentration is 0.5 to 30% by mass, more preferably 1 to 20% by mass. By doing so, the coatability of the resist composition can be further improved.

The solid content means all components other than the solvent, and as described above, it means the components that form the actinic ray-sensitive or radiation-sensitive film.
The solid content concentration is the mass percentage of the mass of other components excluding the solvent relative to the total mass of the composition of the present invention.
"Total solid content" refers to the total mass of components excluding the solvent from the total composition of the composition of the present invention. Moreover, as described above, the “solid content” is a component excluding the solvent, and may be solid or liquid at 25° C., for example.

<Other additives>
The composition of the present invention contains a dissolution-inhibiting compound, a dye, a plasticizer, a photosensitizer, a light-absorbing agent, and/or a compound that promotes solubility in a developer (for example, a phenolic compound having a molecular weight of 1000 or less, or An alicyclic or aliphatic compound containing a carboxyl group) may further be included.

The "dissolution-inhibiting compound" is a compound with a molecular weight of 3000 or less, which is decomposed by the action of an acid to reduce its solubility in an organic developer.

The composition of the specification is suitably used as a photosensitive composition for EUV exposure.
EUV light has a wavelength of 13.5 nm, which is shorter than ArF (wavelength 193 nm) light and the like, so the number of incident photons is smaller when exposed with the same sensitivity. Therefore, the influence of "photon shot noise", in which the number of photons stochastically varies, is large, leading to deterioration of LER and bridge defects. To reduce the photon shot noise, there is a method of increasing the number of incident photons by increasing the amount of exposure, but this is a trade-off with the demand for higher sensitivity.

<Actinic ray-sensitive or radiation-sensitive film, pattern forming method>
Although the procedure of the pattern forming method using the above composition is not particularly limited, it preferably includes the following steps.
Step 1: A step of forming an actinic ray-sensitive or radiation-sensitive film on a substrate using an actinic ray-sensitive or radiation-sensitive resin composition Step 2: A step of exposing the actinic ray-sensitive or radiation-sensitive film 3: Step of developing the exposed actinic ray-sensitive or radiation-sensitive film with a developer Below, the procedure of each of the above steps will be described in detail.

(Step 1: actinic ray-sensitive or radiation-sensitive film forming step)
Step 1 is a step of forming an actinic ray-sensitive or radiation-sensitive film on a substrate using an actinic ray-sensitive or radiation-sensitive resin composition.

A method for forming an actinic ray-sensitive or radiation-sensitive film (preferably a resist film) on a substrate from the actinic ray-sensitive or radiation-sensitive resin composition includes, for example, coating the composition of the present invention on the substrate. method.
In addition, it is preferable to filter the composition of the present invention before application, if necessary. The pore size of the filter is preferably 0.1 µm or less, more preferably 0.05 µm or less, and even more preferably 0.03 µm or less. Filters are preferably made of polytetrafluoroethylene, polyethylene, or nylon.

The compositions of the present invention can be applied onto substrates such as those used in the manufacture of integrated circuit devices (eg, silicon, silicon dioxide coatings) by any suitable coating method such as a spinner or coater. The coating method is preferably spin coating using a spinner. The rotation speed for spin coating using a spinner is preferably 1000 to 3000 rpm.
After application of the composition of the present invention, the substrate may be dried to form an actinic ray-sensitive or radiation-sensitive film. If necessary, various undercoat films (inorganic film, organic film, antireflection film) may be formed under the actinic ray-sensitive or radiation-sensitive film.

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

Although the film thickness of the actinic ray-sensitive or radiation-sensitive film is not particularly limited, it is preferably 10 to 120 nm from the viewpoint of forming finer patterns with higher precision. In particular, when EUV exposure is used, the film thickness of the actinic ray-sensitive or radiation-sensitive film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. In the case of ArF liquid immersion exposure, the thickness of the actinic ray-sensitive or radiation-sensitive film is more preferably 10 to 120 nm, still more preferably 15 to 90 nm.

A topcoat composition may be used to form a topcoat on the upper layer of the actinic ray-sensitive or radiation-sensitive film.
Preferably, the topcoat composition does not mix with the actinic ray-sensitive or radiation-sensitive film and can be uniformly applied over the actinic ray- or radiation-sensitive film. The topcoat is not particularly limited, and a conventionally known topcoat can be formed by a conventionally known method. can be formed.
For example, it is preferable to form a topcoat containing a basic compound as described in JP-A-2013-61648 on the actinic ray-sensitive or radiation-sensitive film. Specific examples of basic compounds that the topcoat may contain include basic compounds that the resist composition may contain.
The topcoat also preferably contains a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond.

(Step 2: Exposure step)
Step 2 is the step of exposing the actinic ray-sensitive or radiation-sensitive film.
Examples of the exposure method include a method of irradiating the formed actinic ray-sensitive or radiation-sensitive film with actinic rays or radiation through a predetermined mask.
Actinic rays or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams, preferably 250 nm or less, more preferably 220 nm or less, 1 to 200 nm Particularly preferred are wavelengths of deep UV light, specifically KrF excimer lasers (248 nm), ArF excimer lasers (193 nm), _F2 excimer lasers (157 nm), EUV (13.5 nm), X-rays, and electron beams.

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

(Step 3: Development step)
Step 3 is a step of developing the exposed actinic ray-sensitive or radiation-sensitive film using a developer to form a pattern.
The developer may be an alkaline developer or a developer containing an organic solvent (hereinafter also referred to as an organic developer).

Examples of the developing method include a method of immersing the substrate in a tank filled with a developer for a certain period of time (dip method), and a method of developing by standing the developer on the surface of the substrate for a certain period of time by raising the developer by surface tension (puddle method). method), a method of spraying the developer onto the substrate surface (spray method), and a method of continuously discharging the developer while scanning the developer discharge nozzle at a constant speed onto the substrate rotating at a constant speed (dynamic dispensing method). ).
Further, after the step of developing, a step of stopping development may be performed while replacing the solvent with another solvent.
The development time is not particularly limited as long as the resin in the unexposed area is sufficiently dissolved, and is preferably 10 to 300 seconds, more preferably 20 to 120 seconds.
The temperature of the developer is preferably 0 to 50°C, more preferably 15 to 35°C.

It is preferable to use an alkaline aqueous solution containing alkali as the alkaline developer. Although the type of alkaline aqueous solution is not particularly limited, for example, quaternary ammonium salts represented by tetramethylammonium hydroxide, inorganic alkalis, primary amines, secondary amines, tertiary amines, alcohol amines, or cyclic amines. and an alkaline aqueous solution containing Among them, the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt represented by tetramethylammonium hydroxide (TMAH). Suitable amounts of alcohols, surfactants and the like may be added to the alkaline developer. The alkali concentration of the alkali developer is usually preferably 0.1 to 20% by mass. The pH of the alkaline developer is preferably 10.0 to 15.0.

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

A plurality of the above solvents may be mixed, or may be mixed with a solvent 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, even more preferably less than 10% by mass, and particularly preferably substantially free of water.
The content of the organic solvent in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, and 90% by mass or more and 100% by mass with respect to the total amount of the developer. The following are more preferable, and 95% by mass or more and 100% by mass or less are particularly preferable.

(Other processes)
The pattern forming method preferably includes a step of washing with a rinse after step 3.

Pure water is an example of the rinse solution used in the rinse step after the step of developing with an alkaline developer. An appropriate amount of surfactant may be added to pure water.
An appropriate amount of surfactant may be added to the rinse solution.

The rinse solution used in the rinse step after the development step using the 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 should contain at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. is preferred.

The method of the rinsing step is not particularly limited. For example, a method of continuously discharging the rinsing liquid onto the substrate rotating at a constant speed (rotation coating method), or a method of immersing the substrate in a tank filled with the rinsing liquid for a certain period of time. a method (dip method) and a method of spraying a rinse liquid onto the substrate surface (spray method).
Also, the pattern forming method may include a heating step (Post Bake) after the rinsing step. In this step, the developing solution and the rinse solution remaining between the patterns and inside the patterns due to baking are removed. In addition, this process smoothes the resist pattern, and has the effect of improving the roughness of the surface of the pattern. The heating step after the rinsing step is usually carried out at 40 to 250° C. (preferably 90 to 200° C.) for 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

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

Various materials used in the composition of the present invention and the pattern forming method of the present specification (e.g., solvent, developer, rinse, composition for forming an antireflection film, composition for forming a topcoat, etc.) It is preferable not to contain impurities such as The content of impurities contained in these materials is preferably 1 mass ppm or less, more preferably 10 mass ppb or less, still more preferably 100 mass ppt or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. The lower limit is not particularly limited, and is preferably 0 mass ppt or more. Here, examples of metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn.

　An example of a method for removing impurities such as metals from various materials is filtration using a filter. Details of filtration using filters are described in paragraph [0321] of WO2020/004306.

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

In addition to filter filtration, impurities may be removed with an adsorbent, or filter filtration and adsorbent may be used in combination. As the adsorbent, known adsorbents can be used. For example, inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon can be used. In order to reduce impurities such as metals contained in the various materials described above, it is necessary to prevent metal impurities from entering during the manufacturing process. Whether the metal impurities are sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of the metal component contained in the cleaning liquid used for cleaning the manufacturing equipment. The content of the metal component contained in the cleaning liquid after use is preferably 100 mass ppt (parts per trillion) or less, more preferably 10 mass ppt or less, and even more preferably 1 mass ppt or less. The lower limit is not particularly limited, and is preferably 0 mass ppt or more.

Organic processing liquids such as rinsing liquids should contain conductive compounds to prevent damage to chemical piping and various parts (filters, O-rings, tubes, etc.) due to electrostatic charging and subsequent electrostatic discharge. may be added. The conductive compound is not particularly limited, and examples thereof include methanol. The amount added is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, from the viewpoint of maintaining preferable developing properties or rinsing properties. The lower limit is not particularly limited, and is preferably 0.01% by mass or more.
As the chemical liquid pipe, for example, SUS (stainless steel), antistatic treated polyethylene, polypropylene, or various pipes coated with fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) can be used. Antistatic treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) can also be used for filters and O-rings.

<Method for manufacturing electronic device>
The present specification also relates to an electronic device manufacturing method, including the pattern forming method described above, and an electronic device manufactured by this manufacturing method.
A preferred embodiment of the electronic device of the present specification includes a mode in which it is installed in electric/electronic equipment (household appliances, OA (Office Automation), media-related equipment, optical equipment, communication equipment, etc.).

The present invention will be described in more detail below based on examples. The materials, amounts used, ratios, processing details, and processing procedures shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limited by the examples shown below.

[Various Components of Actinic Ray-Sensitive or Radiation-Sensitive Resin Composition]
[Resin (A)]
Resins A-1 to A-10 were used as the resin (A).
Table 2 shows the content (mol %), weight average molecular weight (Mw), and degree of dispersion (Mw/Mn) of each repeating unit contained in each resin. The content of repeating units is the ratio (molar ratio) of each repeating unit to all repeating units contained in each resin. Each repeating unit is indicated by the structure of the corresponding monomer.
The weight average molecular weight (Mw) and the degree of dispersion (Mw/Mn) of the resin were measured by GPC (carrier: tetrahydrofuran (THF)) (in terms of polystyrene). The content of repeating units was measured by ¹³ C-NMR (nuclear magnetic resonance).

The structural formulas of the monomers (monomers corresponding to each repeating unit) listed in Table 2 are shown below. Me represents a methyl group.

[Synthesis of resin A-1]
Cyclohexanone (62 g) was heated to 85° C. under a stream of nitrogen. While stirring this liquid, the monomer represented by the formula (M-2) (25 g), the monomer represented by the formula (MP-1) (8.6 g), cyclohexanone (78.4 g) and 2,2' A mixed solution (33.6 g) of a cyclohexanone solution (10% by mass) of dimethyl azobisisobutyrate (V-601, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added dropwise over 3 hours to obtain a reaction solution. After the dropwise addition was completed, the reaction solution was stirred at 85° C. for another 3 hours. After allowing the obtained reaction solution to cool, reprecipitating using a large amount of a mixed solvent of ethyl acetate / heptane = 1/9 (mass ratio), filtering, and vacuum drying the obtained solid to obtain a resin A-1 (28 g) was obtained.

Other resins (A) used in Examples were synthesized in the same manner as above.

[Compound (C)]
The structures of compounds C-1 through C-22, CC-1 through CC-2 are described below. Although compounds CC-1 and CC-2 are outside the scope of compound (C), they are described as compound (C) for convenience. Me represents a methyl group.
Table 3 also shows the HOMO value of the acid generated from each compound. The HOMO value was determined by the method described above.

<Synthesis Example 1: Synthesis of Compound (C-1)>
To 20.0 g of 2,4,6-trimethoxybenzoic acid were added 530 g of methylene chloride and then 160 g of a 20% aqueous solution of triphenylsulfonium carbonate, followed by stirring at room temperature (23° C.) for 30 minutes. After removing the aqueous layer, 80.0 g of distilled water was added, and the liquid separation operation was repeated four times. The solvent in the organic layer was distilled off under reduced pressure, and 150 g of acetonitrile was added and dissolved. 400 g of isopropyl ether was added, the mixture was stirred at room temperature, and the resulting solid was filtered to obtain 29.9 g of compound (C-1).

Compounds C-2 to C-22 and CC-1 to CC-2 were synthesized in the same manner.

<Photoacid generator (B)>
The structure of the photoacid generator (B) used is shown below.

<Surfactant>
W-1 to W-4 below were used as surfactants.
W-1: Megafac R08 (manufactured by DIC Corporation; fluorine and silicon type)
W-2: Megaface F176 (manufactured by Dainippon Ink and Chemicals Co., Ltd.; fluorine-based)
W-3: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.; fluorine-based)
W-4: PF656 (manufactured by OMNOVA; fluorine-based)

<Solvent>
The solvents used are shown below.
S-1: Propylene glycol monomethyl ether acetate (PGMEA: 1-methoxy-2-acetoxypropane)
S-2: propylene glycol monomethyl ether (PGME: 1-methoxy-2-propanol)
S-3: Cyclohexanone S-4: Ethyl lactate S-5: γ-butyrolactone

(Examples 1-1 to 1-25, 2-1 to 2-25, 3-1 to 3-25, 4-1 to 4-25, Comparative Examples 1-1 to 1-2, 2-1 to 2 -2, 3-1 to 3-2, and 4-1 to 4-2)
<Preparation of resist composition>
The components shown in Table 4 were dissolved in the solvent shown in Table 4 to prepare a solution having a solid concentration of 3.0% by mass. prepared.
In addition, solid content means all the components other than a solvent. The resulting resist compositions were used in Examples and Comparative Examples.
In the table, the "Amount" column shows the content (% by mass) of each component with respect to the total solid content in the resist composition. In addition, the amounts (mass parts) of the solvents used are shown in the table.

<Examples 1-1 to 1-25, Comparative Examples 1-1 to 1-2>
[Pattern formation method (1): EB exposure, alkali development (positive)]
The above resist composition is coated on a 6-inch Si wafer that has been previously treated with hexamethyldisilazane (HMDS) using a Tokyo Electron spin coater Mark 8, and dried on a hot plate at 100° C. for 60 seconds. A resist film having a thickness of 100 nm was obtained. Here, 1 inch is 0.0254 m.
Similar results can be obtained by replacing the Si wafer with a chromium substrate.
The wafer coated with the resist film obtained above was subjected to pattern irradiation using an electron beam lithography system (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). At this time, drawing was performed so as to form a line and space of 1:1. After electron beam lithography, the film was heated on a hot plate at 100° C. for 60 seconds, developed with a 2.38% by mass tetramethylammonium hydroxide aqueous solution for 30 seconds, rinsed with pure water, and rotated at 4000 rpm. After rotating the wafer for 30 seconds, it was heated at 95° C. for 60 seconds to obtain a 1:1 line-and-space resist pattern with a line width of 35 nm.

<Performance evaluation>
[Roughness performance]
Roughness performance was evaluated by LER (Line Edge Roughness).
A 1:1 line-and-space pattern with a line width of 35 nm prepared by the above method was observed using a scanning electron microscope (S-4300 manufactured by Hitachi, Ltd.). Then, the distance between the reference line where the edge should be and the actual edge was measured for 30 equally spaced points included in the length direction of 35 μm. Then, the standard deviation of this distance was obtained to calculate 3σ. This 3σ was defined as "LER (nm)".
Using the resist composition (resist composition (A)) within one week after production in an environment of 4° C., the pattern was formed as described above, and the LER (nm) was calculated. The smaller the value, the better the performance.

We also evaluated "changes in roughness performance over time" as follows.

[Change in roughness performance over time]
Changes in roughness performance over time were evaluated by changes in LER (Line Edge Roughness) over time.
As described above, the resist composition (resist composition (A)) manufactured within one week in an environment of 4° C. was used to form a pattern as described above, and the LER (nm) was calculated.
After production, the resist composition (resist composition (B)) after being left for 3 months in an environment of 4 ° C. is used to form a pattern as described above, LER (nm) (roughness after aging performance) was calculated.
The difference (nm) between the LER based on the resist composition (A) and the LER based on the resist composition (B) was defined as variation in roughness performance over time (also referred to as "variation in roughness performance"). A smaller value indicates better performance.

Table 5 shows the obtained evaluation results.

<Examples 2-1 to 2-25, Comparative Examples 2-1 to 2-2>
[Pattern formation method (2): EB exposure, organic solvent development (negative)]
The above resist composition is coated on a 6-inch Si wafer that has been previously treated with hexamethyldisilazane (HMDS) using a Tokyo Electron spin coater Mark 8, and dried on a hot plate at 100° C. for 60 seconds. A resist film having a thickness of 100 nm was obtained.
Similar results can be obtained by replacing the Si wafer with a chromium substrate.

The wafer coated with the resist film obtained above was subjected to pattern irradiation using an electron beam lithography system (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). At this time, drawing was performed so as to form a line and space of 1:1. After electron beam lithography, it was heated at 100° C. for 60 seconds on a hot plate, developed with n-butyl acetate for 30 seconds, spin-dried, and heated at 95° C. for 60 seconds to obtain a line width of 35 nm. A resist pattern of 1:1 line and space pattern was obtained.

We also evaluated "changes in roughness performance over time" as follows.

Table 6 shows the obtained evaluation results.

(EUV exposure)
<Examples 3-1 to 3-25, Comparative Examples 3-1 to 3-2>
[Pattern formation method (3): EUV exposure, alkali development (positive)]
An underlayer film forming composition AL412 (manufactured by Brewer Science) was applied onto a silicon wafer and baked at 205° C. for 60 seconds to form an underlayer film having a thickness of 20 nm. A resist composition shown in Table 7 was applied thereon and baked at 100° C. for 60 seconds to form a resist film having a thickness of 40 nm.
Using an EUV exposure apparatus (Exitech, Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36), pattern irradiation was performed on the silicon wafer having the obtained resist film. rice field. As a reticle, a mask having a line size of 35 nm and a line:space ratio of 1:1 was used.
The exposed resist film was baked at 90° C. for 60 seconds, developed with a tetramethylammonium hydroxide aqueous solution (2.38 mass %) for 30 seconds, and then rinsed with pure water for 30 seconds. After that, it was spin-dried to obtain a positive pattern.

We also evaluated "changes in roughness performance over time" as follows.

Table 7 shows the obtained evaluation results.

<Examples 4-1 to 4-25, Comparative Examples 4-1 to 4-2>
<Pattern Forming Method (4): EUV Exposure, Organic Solvent Development (Negative)>
An underlayer film forming composition AL412 (manufactured by Brewer Science) was applied onto a silicon wafer and baked at 205° C. for 60 seconds to form an underlayer film having a thickness of 20 nm. A resist composition shown in Table 8 was applied thereon and baked at 100° C. for 60 seconds to form a resist film having a thickness of 40 nm.
Using an EUV exposure apparatus (Exitech, Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36), pattern irradiation was performed on the silicon wafer having the obtained resist film. rice field. As a reticle, a mask having a line size of 35 nm and a line:space ratio of 1:1 was used.
The exposed resist film was baked at 90° C. for 60 seconds, developed with n-butyl acetate for 30 seconds, and spin-dried to obtain a negative pattern.

We also evaluated "changes in roughness performance over time" as follows.

Table 8 shows the obtained evaluation results.

As shown in Tables 5 to 8 above, it was confirmed that the resist composition of the present invention was extremely excellent in roughness performance when a fine pattern was formed by alkali development or organic solvent development. On the other hand, the resist compositions of Comparative Examples were insufficient in this performance.
Further, as shown in Tables 5 to 8, when the anion portion in the ionic compound (C) contained in the resist composition of the present invention does not correspond to the above (1) and (2), the roughness performance over time is further improved. It was confirmed that fluctuations were suppressed.

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 invention.
This application is based on a Japanese patent application (Japanese Patent Application No. 2022-012434) filed on January 28, 2022, the contents of which are incorporated herein by reference.

Claims

(A) a resin that decomposes under the action of an acid to increase its polarity, and (C) a compound that generates an acid upon irradiation with an actinic ray or radiation, the ion having an anion moiety represented by the following general formula (I): Actinic ray-sensitive or radiation-sensitive resin composition containing a chemical compound,
Actinic ray-sensitive or radiation-sensitive resin composition, wherein the HOMO of the acid is -6.50 eV or more.

In general formula (I),
L 1 represents a single bond or a divalent linking group.
W represents a hydrocarbon ring or a heterocyclic ring.
The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, wherein the anion moiety represented by the general formula (I) does not correspond to the following (1) and (2).
(1) ring W has one or more selected from the group consisting of -OH, -COO- and -COOH as ring members adjacent to the carbon atom bonded to -L 1 C(=O) O- ; (2) ring W has, as a ring member, -L 1 C(=O)O - in addition to the carbon atoms bonded to -, one or more carbon atoms, and the ring When W has two or more groups selected from the group consisting of —OH and —COO — and —COOH via said one or more carbon atoms as said ring members
2. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, wherein the anion moiety is an anion represented by formula (I)-1.

In general formula (I)-1,
R 1 to R 2 each independently represent a hydrogen atom or a substituent.
R3 represents a hydrogen atom or a substituent.
L2 represents a single bond or a divalent linking group.
R 1 and R 2 may combine with each other to form a ring. R 3 and L 2 may combine with each other to form a ring.
3. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 2, wherein the anion portion is an anion represented by (I)-2.

In general formula (I)-2,
R 4 and R 5 each independently represent a hydrogen atom or a substituent other than OH, COO 2 — and COOH.
R 6 to R 8 each independently represent a hydrogen atom or a substituent. Two or more of R 4 to R 8 may combine with each other to form a ring.
In the general formula (I)-2, the ring to which the COO — group is bonded is a benzene ring as a monocyclic ring, or formed by bonding two or more of R 4 to R 8 to each other (benzene ring The actinic ray-sensitive or radiation-sensitive according to claim 4, which is polycyclic and has 6 to 14 carbon atoms as ring members constituting the ring to which the COO 2 — group is bonded. Resin composition.
6. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 5, wherein the ring to which the COO 2 — group is bonded has 6 to 10 carbon atoms as ring members.
The actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1 to 6, wherein the cation moiety of the ionic compound is a sulfonium cation or an iodonium cation.
The resin (A) is selected from the group consisting of repeating units represented by the following general formula (A1), repeating units represented by the following general formula (A2), and repeating units represented by the following general formula (A3). The actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1 to 6, which has at least one

In general formula (A1),
R a1 , R a2 and R a3 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
L a1 represents a single bond or a divalent linking group.
Ar a1 represents an aromatic ring group.
R a4 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
R a5 and R a6 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
R a4 and R a5 may combine with each other to form a ring. Ar a1 may combine with R a3 or R a4 to form a ring.
In general formula (A2),
R a7 , R a8 and R a9 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
La2 represents a single bond or a divalent linking group.
Ar a2 represents an aromatic ring group.
R a10 , R a11 and R a12 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group. Two of R a10 , R a11 and R a12 may combine with each other to form a ring.
In general formula (A3),
R a13 , R a14 and R a15 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
La3 represents a single bond or a divalent linking group.
Ar a3 represents an aromatic ring group.
R a16 , R a17 and R a18 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group. Two of R a16 , R a17 and R a18 may combine with each other to form a ring.
The actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1 to 6, wherein the resin (A) has a repeating unit having a group that generates an acid upon exposure to actinic rays or radiation.
The actinic ray-sensitive or radiation-sensitive according to any one of claims 1 to 6, wherein the content of the ionic compound (C) is 10% by mass or more relative to the total solid content of the composition. Resin composition.
An actinic ray-sensitive or radiation-sensitive film formed from the actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1 to 6.
A step of forming an actinic ray-sensitive or radiation-sensitive film on a substrate from the actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1 to 6;
exposing the actinic ray-sensitive or radiation-sensitive film;
and developing the exposed actinic ray-sensitive or radiation-sensitive film with a developer to form a pattern.
A method for manufacturing an electronic device, including the pattern forming method according to claim 12.