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

Abstract

Provided are: an actinic ray–sensitive or radiation-sensitive resin composition containing a resin (A) having an acid-decomposable group and a salt compound (B) that generates a Lewis acid capable of decomposing the acid-decomposable group when irradiated with actinic rays or radiation; a resist film using the actinic ray–sensitive or radiation-sensitive resin composition; a pattern-forming method; and an electronic device manufacturing method comprising the pattern-forming method.

Description

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

[0001] The present invention relates to an actinic ray- or radiation-sensitive resin composition, an actinic ray- or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device. More specifically, the present invention relates to an actinic ray- or radiation-sensitive resin composition, an actinic ray- or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device that can be suitably used in ultra-microlithography processes applicable to processes for manufacturing VLSI (Large Scale Integration) and high-capacity microchips, processes for creating molds for nanoimprinting, and processes for manufacturing high-density information recording media, as well as other photofabrication processes.

[0002] Conventionally, in the manufacturing process of semiconductor devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration), microfabrication is performed by lithography using resist compositions. In recent years, with the increasing integration density of integrated circuits, there has been a demand for ultrafine pattern formation in the submicron or quarter-micron range. Accordingly, there has been a trend toward shorter exposure wavelengths, from g-line to i-line and then to KrF excimer laser light, and currently, exposure machines using ArF excimer lasers with a wavelength of 193 nm as a light source have been developed. Furthermore, as a technique for further improving resolution, the so-called immersion method, in which a high refractive index liquid (hereinafter also referred to as "immersion liquid") is filled between the projection lens and the sample, has been developed.

[0003] Currently, in addition to excimer laser light, lithography using electron beams (EB), X-rays, extreme ultraviolet rays (EUV), etc. is also being developed. Accordingly, resist compositions that are effectively sensitive to various types of actinic rays or radiation have been developed.

[0004] Patent Document 1 describes a resist composition containing a resin that has an acid-labile group and is insoluble or slightly soluble in an alkaline aqueous solution but becomes soluble in the alkaline aqueous solution by the action of an acid, an acid generator, a basic compound, and a boron-containing compound.

[0005] Japanese Patent Application Publication No. 2011-81358

[0006] Recently, the performance required of resist compositions and pattern forming methods has become increasingly higher. In particular, further improvements are required in terms of resolution and LWR (Line Width Roughness).

[0007] Therefore, an object of the present invention is to provide an actinic ray-sensitive or radiation-sensitive resin composition capable of forming a pattern excellent in resolution and LWR. Another object of the present invention is to provide a resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition, a pattern forming method, and a method for manufacturing an electronic device.

[0008] The present inventors have found that the above problems can be solved by the following configuration.

[0009] [1] An actinic ray-sensitive or radiation-sensitive resin composition comprising: (A) a resin having an acid-decomposable group; and (B) a salt compound that generates a Lewis acid capable of decomposing the acid-decomposable group upon irradiation with actinic rays or radiation.

[0010] [2] The actinic ray-sensitive or radiation-sensitive resin composition according to [1], wherein the salt compound (B) is a salt compound that generates the Lewis acid by decomposition of an anion in the salt compound (B) upon irradiation with actinic rays or radiation.

[0011] [3] The actinic ray-sensitive or radiation-sensitive resin composition according to [1] or [2], wherein the salt compound (B) has at least one iodine atom on the anion. [4] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [3], wherein the salt compound (B) has an anion containing a Group 13 element or a Group 14 element. [5] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [4], wherein the salt compound (B) has an anion containing boron or silicon.

[0012] [6] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [5], wherein the salt compound (B) is an onium salt compound represented by any one of the following general formulas (BI) to (BIII):

[0013]

[0014] In general formulas (BI) to (BIII), R １ ~R ３ R each independently represents an aromatic ring group. ４ ~R １０ R each independently represents an aromatic ring group. １ ~R ３ At least two of R ４ ~R ６ and at least two of R ７ ~R １０ At least two of X may be bonded to each other to form a ring structure. １ ~X ３ Each of Y independently represents a monovalent organic group. １ ＋ ~Y ３ ＋ each independently represents a cation.

[0015] [7] R in the above general formula (BI) １ ~R ３ [8] The actinic ray-sensitive or radiation-sensitive resin composition according to [6], wherein at least one of Y in the above general formulae (BI) to (BIII) has an electron-withdrawing group. １ ＋ ~Y ３ ＋[9] The actinic ray-sensitive or radiation-sensitive resin composition according to [6] or [7], wherein Y in the above general formulas (BI) to (BIII) is a cation that decomposes upon irradiation with actinic rays or radiation. １ ＋ ~Y ３ ＋

[10] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [6] to [8], wherein Y in the above general formulae (BI) to (BIII) is a sulfonium cation or an iodonium cation. １ ＋ ~Y ３ ＋

[10] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [6] to [9], wherein is a triarylsulfonium cation or a diaryliodonium cation.

[0016]

[11] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to

[10] , further comprising a compound other than the salt compound (B) that generates an acid upon irradiation with actinic rays or radiation.

[12] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to

[11] , further comprising a photodegradable base.

[0017]

[13] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to

[12] , further comprising at least one of the following compounds (I) and (II): Compound (I): A compound having one or more structural moieties X and one or more structural moieties Y, which generates an acid containing the following first acidic moiety derived from the structural moiety X and the following second acidic moiety derived from the structural moiety Y upon irradiation with actinic rays or radiation. Structural moiety X: Anionic moiety A １ － and the cationic moiety M １１ ＋ and HA is produced by irradiation with actinic rays or radiation. １ Structural moiety Y: anionic moiety A, which forms a first acidic moiety represented by the formula: ２ － and the cationic moiety M １２ ＋and HA is produced by irradiation with actinic rays or radiation. ２ However, compound (I) satisfies the following condition I. Condition I: In compound (I), the cationic moiety M in the structural moiety X is １１ ＋ and the cationic moiety M in the structural moiety Y １２ ＋ H ＋ The compound PI in which the cation moiety M in the structural moiety X is replaced by １１ ＋ H ＋ HA is replaced by １ and the cationic moiety M in the structural moiety Y. １２ ＋ H ＋ HA is replaced by ２ and the acid dissociation constant a2 is greater than the acid dissociation constant a1. Compound (II): A compound having two or more of the above structural moieties X and one or more of the following structural moieties Z, which generates an acid upon irradiation with actinic rays or radiation, the compound including a compound that generates an acid containing two or more of the first acidic moieties derived from the structural moiety X and the structural moiety Z. Structural moiety Z: a ​​non-ionic moiety capable of neutralizing an acid

[0018]

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

[13] .

[15] A pattern forming method comprising the steps of: forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of items [1] to

[13] ; exposing the resist film; and developing the exposed resist film using a developer.

[16] A method for producing an electronic device, comprising the pattern forming method according to item

[15] .

[0019] The present invention provides an actinic ray-sensitive or radiation-sensitive resin composition capable of forming a pattern excellent in resolution and LWR. The present invention also provides a resist film, a pattern forming method, and a method for manufacturing an electronic device, which use the actinic ray-sensitive or radiation-sensitive resin composition.

[0020] The present invention will be described in detail below. The following description of the components will be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0021] In this specification, "actinic rays" or "radiation" refers to, for example, the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays (EUV), X-rays, soft X-rays, and electron beams (EB). In this specification, "light" refers to actinic rays or radiation. Unless otherwise specified, in this specification, "exposure" includes not only exposure using the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays, X-rays, and EUV, but also drawing using particle beams such as electron beams and ion beams. In this specification, the word "to" is used to mean that the numerical values ​​before and after it are included as the lower and upper limits.

[0022] In this specification, (meth)acrylate refers to at least one of acrylate and methacrylate, and (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid.

[0023] In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (also referred to as molecular weight distribution) (Mw / Mn) of a resin are defined as polystyrene-equivalent values ​​measured by gel permeation chromatography (GPC) using a GPC apparatus (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40° C., flow rate: 1.0 mL / min, detector: differential refractive index detector).

[0024] In the description of groups (atomic groups) in this specification, unless contrary to the spirit of the present invention, notations that do not specify whether they are substituted or unsubstituted include groups that contain a substituent as well as groups that do not have a substituent. For example, the term "alkyl group" includes not only alkyl groups that do not have a substituent (unsubstituted alkyl groups) but also alkyl groups that have a substituent (substituted alkyl groups). Furthermore, the term "organic group" in this specification refers to a group containing at least one carbon atom. Unless otherwise specified, a monovalent substituent is preferred as the substituent. Examples of the substituent include monovalent non-metallic atomic groups excluding hydrogen atoms, which can be selected, for example, from the following substituents T:

[0025] (Substituent T) Examples of the substituent T include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; alkoxy groups such as a methoxy group, an ethoxy group, and a tert-butoxy group; a cycloalkyloxy group; an aryloxy group such as a phenoxy group and a p-tolyloxy group; an alkoxycarbonyl group such as a methoxycarbonyl group and a butoxycarbonyl group; a cycloalkyloxycarbonyl group; an aryloxycarbonyl group such as a phenoxycarbonyl group; an acyloxy group such as an acetoxy group, a propionyloxy group, and a benzoyloxy group; an acetyl group, a benzoyl group, an isobutyryl group, an acryloyl group, a methacrylate group, a methyl ... Examples of the substituent T include acyl groups such as thiazolyl and methoxalyl groups; sulfanyl groups; alkylsulfanyl groups such as methylsulfanyl and tert-butylsulfanyl groups; arylsulfanyl groups such as phenylsulfanyl and p-tolylsulfanyl groups; alkylsulfonyl groups; arylsulfonyl groups; alkyl groups; alkenyl groups; cycloalkyl groups; aryl groups; heteroaryl groups; hydroxy groups; carboxyl groups; formyl groups; sulfo groups; cyano groups; alkylaminocarbonyl groups; arylaminocarbonyl groups; sulfonamide groups; silyl groups; amino groups; carbamoyl groups; etc. In addition, when these substituents can further have one or more substituents, examples of the substituent T also include groups having one or more substituents selected from the above-mentioned substituents as the further substituents (e.g., monoalkylamino groups, dialkylamino groups, arylamino groups, trifluoromethyl groups, etc.).

[0026] In this specification, the bonding direction of a divalent group is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "X-Y-Z", Y may be -CO-O- or -O-CO-. The compound may be either "X-CO-O-Z" or "X-O-CO-Z".

[0027] In this specification, the acid dissociation constant (pKa) refers to the pKa in an aqueous solution, and specifically, is a value determined by calculation using the following software package 1 based on a database of Hammett's substituent constants and known literature values. All pKa values ​​described in this specification are values ​​determined by calculation using this software package. Software package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0028] The pKa can also be calculated by molecular orbital calculation. A specific method for this is to calculate the pKa of H in an aqueous solution based on the thermodynamic cycle. ＋ One method is to calculate the dissociation free energy. ＋ The dissociation free energy can be calculated by, for example, DFT (density functional theory), but various other methods have been reported in the literature, and the method is not limited to these. There are several software programs that can perform DFT, and Gaussian 16 is an example.

[0029] In this specification, pKa refers to a value calculated based on a database of Hammett's substituent constants and publicly known literature values ​​using software package 1, as described above, but if pKa cannot be calculated by this method, a value obtained by Gaussian 16 based on DFT (density functional theory) will be adopted. In this specification, pKa refers to "pKa in aqueous solution" as described above, but if pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" will be adopted.

[0030] In this specification, the term "solid content" refers to components contained in the actinic ray-sensitive or radiation-sensitive resin composition and that form an actinic ray-sensitive or radiation-sensitive film, and does not include solvents. Furthermore, any component contained in the actinic ray-sensitive or radiation-sensitive resin composition and that forms an actinic ray-sensitive or radiation-sensitive film is considered to be a solid content even if it is in a liquid state.

[0031] [Actinic Ray- or Radiation-Sensitive Resin Composition] The actinic ray- or radiation-sensitive resin composition of the present invention (hereinafter also referred to as "resist composition") is an actinic ray- or radiation-sensitive resin composition containing (A) a resin having an acid-decomposable group, and (B) a salt compound that generates a Lewis acid capable of decomposing the acid-decomposable group upon irradiation with actinic rays or radiation.

[0032] Although the reason why a resist composition can form a pattern with excellent resolution and LWR is not entirely clear, the inventors speculate as follows. Compounds (photoacid generators) that generate acid upon exposure to actinic rays or radiation, which are commonly used in resist compositions, generate a Brønsted acid upon exposure. On the other hand, the salt compound (B) contained in the resist composition of the present invention generates a Lewis acid capable of decomposing an acid-labile group upon exposure. The photoacid generator that generates a Lewis acid has high photodecomposition property, and therefore the amount of acid generated in the exposed area increases, further accelerating the decomposition of the acid-labile group contained in the resin (A) in the exposed area. Therefore, the difference in dissolution rate in a developer between the unexposed area and the exposed area (so-called dissolution contrast) increases, enabling the formation of a pattern with excellent resolution and LWR. Furthermore, the inventors speculate that Lewis acids have a larger molecular size than Brønsted acids, which inhibits diffusion, enabling the formation of a pattern with even better resolution and LWR.

[0033] The resist composition may be a positive resist composition or a negative resist composition. Furthermore, the resist composition may be a resist composition for alkali development or a resist composition for organic solvent development. The resist composition may be a chemically amplified resist composition or a non-chemically amplified resist composition, but is preferably a chemically amplified resist composition.

[0034] <Resin (A)> The resist composition contains a resin (A) (also simply referred to as "resin (A)") that has a group whose polarity increases upon the action of acid (acid-decomposable group).

[0035] (Repeating unit having an acid-decomposable group) The resin (A) preferably contains a repeating unit having an acid-decomposable group. The acid-decomposable group is typically a group that decomposes under the action of an acid to generate a polar group. The acid-decomposable group preferably has a structure in which a polar group is protected with a group that leaves under the action of an acid (leaving group). It is preferable that the polarity of the resin (A) increases under the action of an acid, and the solubility in organic solvents decreases. Examples of the polar group include 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, a (alkylsulfonyl) (alkylcarbonyl) methylene group, a (alkylsulfonyl) (alkylcarbonyl) imide group, a bis(alkylcarbonyl) methylene group, a bis(alkylcarbonyl) imide group, a bis(alkylsulfonyl) methylene group, a bis(alkylsulfonyl) imide group, a tris(alkylcarbonyl) methylene group, and a tris(alkylsulfonyl) methylene group, and an acidic group such as an alcoholic hydroxyl group. Among these, 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.

[0036] Examples of the group that is eliminated by the action of an acid include groups represented by formulae (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)

[0037] In formula (Y1) and formula (Y2), Rx １ ~Rx ３ Rx each independently represents 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). １ ~Rx ３ When all of Rx are alkyl groups (linear or branched), １ ~Rx ３ At least two of Rx are preferably methyl groups. １ ~Rx ３ each independently preferably represents a linear or branched alkyl group, and Rx １ ~Rx ３ More preferably, Rx each independently represents a linear alkyl group. １ ~Rx ３ may be bonded to form a monocyclic or polycyclic ring. １ ~Rx ３ The alkyl group of Rx is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. １ ~Rx ３ The cycloalkyl group of Rx is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. １ ~Rx ３ The aryl group in Rx is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. １ ~Rx ３The alkenyl group in Rx is preferably a vinyl group. １ ~Rx ３ The ring formed by combining the two is preferably a cycloalkyl group. １ ~Rx ３ The cycloalkyl group formed by bonding the two is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, and more preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms. １ ~Rx ３ In the cycloalkyl group formed by bonding these two, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. The group represented by formula (Y1) or formula (Y2) can be, for example, Rx １ is a methyl group or an ethyl group, and Rx ２ and Rx ３ and Rx are preferably bonded to form the above-mentioned cycloalkyl group. When the actinic ray-sensitive or radiation-sensitive resin composition is, for example, a resist composition for EUV exposure, １ ~Rx ３ an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group represented by the formula: １ ~Rx ３ The ring formed by bonding these two groups preferably further has a fluorine atom or an iodine atom as a substituent.

[0038] In formula (Y3), R ３６ ~R ３８ R each independently represents a hydrogen atom or a monovalent organic group. ３７ and R ３８ may be bonded to each other to form a ring. Examples of the monovalent organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. ３６is also preferably 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 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. R ３８ may bond with another substituent on the main chain of the repeating unit to form a ring. ３８ The group formed by bonding together R and another substituent on the main chain of the repeating unit is preferably an alkylene group such as a methylene group. ３６ ~R ３８ and a monovalent organic group represented by R ３７ and R ３８ It is also preferable that the ring formed by bonding these groups together further has a fluorine atom or an iodine atom as a substituent.

[0039] Formula (Y3) is preferably a group represented by the following formula (Y3-1).

[0040]

[0041] Here, L Ｙ１ and L Ｙ２ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group formed by combining these (for example, a group formed by combining an alkyl group and an aryl group). Ｙ１ represents a single bond or a divalent linking group. Ｙ１represents an alkyl group which may contain a heteroatom, a cycloalkyl group which may contain a heteroatom, an aryl group which may contain a heteroatom, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group, or a group which combines these (for example, a group which combines an alkyl group and a cycloalkyl group). In the alkyl group and the cycloalkyl group, for example, one of the methylene groups may be replaced with a heteroatom such as an oxygen atom, or a group which contains a heteroatom such as a carbonyl group. Ｙ１ and L Ｙ２ Preferably, one of Q is a hydrogen atom, and the other is an alkyl group, a cycloalkyl group, an aryl group, or a group in which an alkylene group and an aryl group are combined. Ｙ１ , M Ｙ１ , and L Ｙ１ At least two of the groups may be bonded to form a ring (preferably a 5- or 6-membered ring). Ｙ２ is preferably a secondary or tertiary alkyl group, and more preferably a tertiary alkyl group. Examples of secondary alkyl groups include an isopropyl group, a cyclohexyl group, and a norbornyl group, and examples of tertiary alkyl groups include a tert-butyl group and an adamantane group. In these embodiments, the Tg (glass transition temperature) and activation energy are high, thereby ensuring film strength and suppressing fogging. In formula (Y3-1), * represents a bonding position.

[0042] 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 be bonded to each other to form a non-aromatic ring. Ar is preferably an aryl group.

[0043] In terms of excellent acid decomposition properties of the repeating unit, when a non-aromatic ring is directly bonded to the polar group (or a residue thereof) in the leaving group protecting the polar group, it is also preferable that the ring atom in the non-aromatic ring adjacent to the ring atom directly bonded to the polar group (or a residue thereof) does not have a halogen atom such as a fluorine atom as a substituent.

[0044] The group that is eliminated by the action of an acid may also be a 2-cyclopentenyl group having a substituent (such as an alkyl group), such as a 3-methyl-2-cyclopentenyl group, or a cyclohexyl group having a substituent (such as an alkyl group), such as a 1,1,4,4-tetramethylcyclohexyl group.

[0045] The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by formula (A).

[0046]

[0047] L １ represents a divalent linking group which may have a fluorine atom or an iodine atom, R １ represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom; R ２ represents a leaving group which is eliminated by the action of an acid and may have a fluorine atom or an iodine atom. １ , R １ , and R ２ At least one of L has a fluorine atom or an iodine atom. １ Examples of the divalent linking group which may have a fluorine atom or an iodine atom and is represented by the formula: ２ -, hydrocarbon groups which may have a fluorine atom or an iodine atom (for example, alkylene groups, cycloalkylene groups, alkenylene groups, arylene groups, etc.), and linking groups in which a plurality of these groups are linked together. １As the alkylene group, -CO-, an arylene group, or -arylene group-alkylene group having a fluorine atom or an iodine atom- is preferred, and -CO- or -arylene group-alkylene group having a fluorine atom or an iodine atom- is more preferred. As the arylene group, a phenylene group is preferred. The alkylene group may be linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the alkylene group having a fluorine atom or an iodine atom is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0048] R １ The alkyl group represented by R may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. １ The total number of fluorine atoms and iodine atoms contained in the alkyl group having a fluorine atom or an iodine atom, represented by the formula (I), is not particularly limited, but is preferably 1 or more, more preferably 1 to 5, and even more preferably 1 to 3. １ The alkyl group represented by the formula (I) may contain a heteroatom other than a halogen atom, such as an oxygen atom.

[0049] R ２ Examples of the leaving group represented by the formulae (Y1) to (Y4) above and which may have a fluorine atom or an iodine atom include leaving groups represented by the formulae (Y1) to (Y4) above and which have a fluorine atom or an iodine atom.

[0050] The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by formula (AI).

[0051]

[0052] In formula (AI), Xa １ represents a hydrogen atom or an alkyl group which may have a substituent. T represents a single bond or a divalent linking group. Rx １ ~Rx ３each independently represents 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). １ ~Rx ３ When all of Rx are alkyl groups (linear or branched), １ ~Rx ３ Preferably, at least two of Rx are methyl groups. １ ~Rx ３ may be bonded to form a monocyclic or polycyclic ring (such as a monocyclic or polycyclic cycloalkyl group).

[0053] Xa １ Examples of the alkyl group represented by the formula (I) which may have a substituent include a methyl group or a —CH ２ -R １１ Examples of the group include a group represented by the following formula: １１ represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. １１ Examples of the monovalent organic group represented by the formula (I) 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, and an alkyl group having 3 or less carbon atoms is preferred, and a methyl group is more preferred. １ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0054] Examples of the divalent linking group for T include 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, and is preferably a -CH ２ - group, -(CH ２ ) ２ - group or -(CH ２ ) ３ The - group is more preferred.

[0055] Rx １ ~Rx ３The alkyl group of Rx is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. １ ~Rx ３ The cycloalkyl group of Rx is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. １ ~Rx ３ The aryl group in Rx is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. １ ~Rx ３ The alkenyl group in Rx is preferably a vinyl group. １ ~Rx ３ As the cycloalkyl group formed by combining the above two, a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group is preferred. Polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group are also preferred. Among these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is preferred. Rx １ ~Rx ３ The cycloalkyl group formed by bonding these two may have, for example, one of the methylene groups constituting the ring replaced with a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. The repeating unit represented by formula (AI) can be, for example, Rx １ is a methyl group or an ethyl group, and Rx ２ and Rx ３ and are preferably bonded to form the above-mentioned cycloalkyl group.

[0056] When each of the above groups has a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.

[0057] The repeating unit represented by formula (AI) may be an acid-decomposable (meth)acrylic acid tertiary alkyl ester repeating unit (Xa １ represents a hydrogen atom or a methyl group, and T represents a single bond).

[0058] The resin (A) may have a repeating unit having an acid-decomposable group containing an unsaturated bond as a 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 preferred.

[0059]

[0060] In formula (B), Xb represents a hydrogen atom, a halogen atom, or an alkyl group which may have a substituent. L represents a single bond or a divalent linking group which may have a substituent. Ry １ ~Ry ３ each independently represents 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, provided that Ry １ ~Ry ３ At least one of R represents an alkenyl group, an alkynyl group, a monocyclic or polycyclic cycloalkenyl group, or a monocyclic or polycyclic aryl group. １ ~Ry ３ may be bonded to form a monocyclic or polycyclic ring (such as a monocyclic or polycyclic cycloalkyl group or cycloalkenyl group).

[0061] The alkyl group represented by Xb, which may have a substituent, is, for example, a methyl group or —CH ２ -R １１ Examples of the group include a group represented by the following formula: １１represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, and examples thereof 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. Xb is preferably a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0062] Examples of the divalent linking group for L include a -Rt- group, a -CO- group, a -COO-Rt- group, a -COO-Rt-CO- group, a -Rt-CO- group, and a -O-Rt- group. In the formula, Rt represents an alkylene group, a cycloalkylene group, or an aromatic ring group, and an aromatic ring group is preferable. L is preferably a -Rt- group, a -CO- group, a -COO-Rt-CO- group, or a -Rt-CO- group. Rt may have a substituent such as a halogen atom, a hydroxyl group, or an alkoxy group.

[0063] Ry １ ~Ry ３ The alkyl group of Ry is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. １ ~Ry ３ The cycloalkyl group of Ry is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. １ ~Ry ３ The aryl group in Ry is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. １ ~Ry ３ The alkenyl group in Ry is preferably a vinyl group. １ ~Ry ３ The alkynyl group in Ry is preferably an ethynyl group. １ ~Ry ３The cycloalkenyl group of Ry is preferably a monocyclic cycloalkyl group having a structure containing a double bond in a part thereof, such as a cyclopentyl group or a cyclohexyl group. １ ~Ry ３ The cycloalkyl group formed by combining the above two groups is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. Among these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferred. １ ~Ry ３ The cycloalkyl group or cycloalkenyl group formed by bonding two of the above is, for example, a group in which one of the methylene groups constituting the ring is substituted with a heteroatom such as an oxygen atom, a carbonyl group, or —SO ２ - group and -SO ３ The repeating unit represented by formula (B) may be substituted with a group containing a hetero atom such as a - group, a vinylidene group, or a combination thereof. In addition, in these cycloalkyl groups or cycloalkenyl groups, one or more ethylene groups constituting the cycloalkane ring or cycloalkene ring may be substituted with a vinylene group. １ is a methyl group, an ethyl group, a vinyl group, an allyl group, or an aryl group, and Ry ２ and Ry ３ and are bonded to form the above-mentioned cycloalkyl group or cycloalkenyl group.

[0064] When each of the above groups has a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.

[0065] The repeating unit represented by formula (B) is preferably an acid-decomposable (meth)acrylic acid tertiary ester repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a —CO— group), an acid-decomposable hydroxystyrene tertiary alkyl ether repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a phenyl group), or an acid-decomposable styrene carboxylic acid tertiary ester 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)).

[0066] Specific examples of repeating units having an acid-decomposable group containing an unsaturated bond include the repeating units described in paragraphs

[0067] to

[0071] of WO 2022 / 024928. The above descriptions are incorporated herein by reference.

[0067] Specific examples of repeating units having an acid-decomposable group are shown below, but are not limited to these. Furthermore, repeating units having an acid-decomposable group described in the examples below are also preferred.

[0068]

[0069] The content of the repeating unit having an acid-decomposable group is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on the total repeating units in the resin (A). The content of the repeating unit having an acid-decomposable group is preferably 90 mol% or less, more preferably 85 mol% or less, and even more preferably 80 mol% or less, based on the total repeating units in the resin (A). The repeating unit having an acid-decomposable group contained in the resin (A) may be one type or two or more types. When the repeating unit having an acid-decomposable group contained in the resin (A) is two or more types, it is preferable that the total content thereof is within the above-mentioned suitable content range.

[0070] (Repeating unit having an acid group) The resin (A) preferably contains a repeating unit having an acid group. Examples of the acid group include a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, and an isopropanol group. In the hexafluoroisopropanol group, one or more fluorine atoms (preferably one to two) may be substituted with a group other than a fluorine atom (such as an alkoxycarbonyl group). Examples of the acid group include the -C(CF ３ )(OH)—CF ２ In addition, one or more fluorine atoms are substituted with a group other than a fluorine atom to form -C(CF ３ )(OH)—CF ２ - may form a ring containing the same. The repeating unit having an acid group is preferably a repeating unit different from the repeating unit having the acid-decomposable group described above. The repeating unit having an acid group may have a fluorine atom or an iodine atom. Specific examples of the repeating unit having an acid group include the repeating units described in

[0088] to

[0089] and

[0103] to

[0110] of WO 2022 / 024928. The above descriptions are incorporated herein by reference.

[0071] The repeating unit having an acid group is preferably a repeating unit having a phenolic hydroxyl group, and the repeating unit having a phenolic hydroxyl group is preferably a repeating unit different from the repeating unit having an acid-decomposable group described above.

[0072] The repeating unit having an acid group is preferably a repeating unit represented by the following formula (Pa1): The resin (A) preferably contains a repeating unit represented by the following formula (Pa1).

[0073]

[0074] In formula (Pa1), R ａ１ and R ａ２ each independently represents a hydrogen atom or a substituent. ａ１ represents a single bond or a divalent linking group. ａ１represents an aromatic ring group. ａ１ And, R ａ２ or L ａ１ may be bonded to by a single bond or via a linking group. Ｘ represents a substituent other than a hydroxy group. n represents an integer of 1 or more and 9 or less. m represents an integer of 0 or more and 8 or less.

[0075] R in formula (Pa1) ａ１ and R ａ２ R each independently represents a hydrogen atom or a substituent. ａ１ and R ａ２ The substituent represented by is not particularly limited, but is preferably an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. ａ１ and R ａ２ The alkyl group represented by may be either linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The alkyl group may have a substituent. R ａ１ and R ａ２ The number of carbon atoms in the cycloalkyl group represented by is not particularly limited, but is preferably 3 to 20, and more preferably 5 to 15. The cycloalkyl group may be a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. The cycloalkyl group may have a substituent. R ａ１ and R ａ２ Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom or an iodine atom is preferred. ａ１ and R ａ２ The alkyl group contained in the alkoxycarbonyl group represented by the formula (I) may be either linear or branched. The number of carbon atoms in the alkyl group contained in the alkoxycarbonyl group is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 3. The alkoxycarbonyl group may have a substituent.

[0076] L in formula (Pa1) ａ１ represents a single bond or a divalent linking group. ａ１ The divalent linking group represented by is not particularly limited, but examples thereof include —COO—, —CONR ａ３ -, an alkylene group, or a group formed by combining two or more of these groups. ａ３ represents a hydrogen atom or an alkyl group. The alkylene group is not particularly limited, but is preferably an alkylene group having 1 to 8 carbon atoms, such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, or an octylene group. The alkylene group may have a substituent. R ａ３ When represents an alkyl group, examples of the alkyl group include alkyl groups having 20 or less carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, and a dodecyl group, and alkyl groups having 8 or less carbon atoms are preferred.

[0077] Ar in formula (Pa1) ａ１ represents an aromatic ring group, specifically an (m+n+1)-valent aromatic ring group. ａ１ The aromatic ring group represented by may be an aromatic hydrocarbon group or an aromatic heterocyclic group. The aromatic hydrocarbon group is preferably a group containing an aromatic hydrocarbon having 6 to 18 carbon atoms, such as benzene, naphthalene, anthracene, or naphthacene. The aromatic heterocyclic group preferably contains at least one heteroatom selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom as a ring member. The aromatic heterocyclic group is preferably a group containing an aromatic heterocycle having 4 to 20 ring atoms, such as thiophene, furan, pyridine, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, or thiazole.

[0078] Ar ａ１ And, R ａ２ or L ａ１ may be bonded to by a single bond or via a linking group. Examples of the linking group include -O-, -S-, -CO-, -CO ２-, -SO-, -SO ２ -, alkylene groups (preferably having 1 to 5 carbon atoms), alkenylene groups (preferably having 2 to 5 carbon atoms), and groups formed by combining two or more of these. The alkylene groups and alkenylene groups may have a substituent.

[0079] R in formula (Pa1) Ｘ represents a substituent other than a hydroxy group. Ｘ Examples of the substituent represented by R include a carboxyl group, a sulfo group, a cyano group, a halogen atom, a hydrocarbon group, an amino group, a nitro group, and a group formed by combining two or more of these. Ｘ Examples of the hydrocarbon group represented by R include an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 5 to 15 carbon atoms), and an alkenyl group (preferably having 2 to 10 carbon atoms). Ｘ The hydrocarbon group represented by may have a substituent. Ｘ The hydrocarbon group represented by is -CH ２ When it contains -, -CH ２ At least one of - is -O-, -CO-, -S- and -SO ２ - may be replaced with at least one selected from the group consisting of Ｘ The substituent represented by the formula (I) preferably has a halogen atom. The halogen atom is preferably a fluorine atom or an iodine atom, and more preferably an iodine atom.

[0080] In formula (Pa1), n ​​represents an integer of 1 or more and 9 or less, preferably an integer of 1 or more and 5 or less, and more preferably an integer of 1 or more and 4 or less.

[0081] In formula (Pa1), m represents an integer of 0 or more and 8 or less, preferably an integer of 0 or more and 4 or less, and more preferably an integer of 0 or more and 3 or less.

[0082] The repeating unit having an acid group is preferably a repeating unit represented by the following formula (Pa2): The resin (A) preferably contains a repeating unit represented by the following formula (Pa2).

[0083]

[0084] In formula (Pa2), R ａ４ represents a hydrogen atom or an alkyl group. ａ２ represents a single bond or —COO—. Ｘ１ represents a halogen atom, a haloalkyl group or a hydrocarbon group. n1 represents an integer of 1 or more and 5 or less. m1 represents an integer of 0 or more and 4 or less. r represents an integer of 0 or more and 3 or less.

[0085] R in formula (Pa2) ａ４ represents a hydrogen atom or an alkyl group. ａ４ The alkyl group represented by may be either linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The alkyl group may have a substituent.

[0086] L in formula (Pa2) ａ２ represents a single bond or —COO—, and preferably represents a single bond.

[0087] In formula (Pa2), r represents an integer of 0 or more and 3 or less, preferably an integer of 0 or more and 2 or less, more preferably 0 or 1, and even more preferably 0. In formula (Pa2), the aromatic ring is benzene when r represents 0, naphthalene when r represents 1, anthracene when r represents 2, and naphthacene when r represents 3.

[0088] R in formula (Pa2) Ｘ１ represents a halogen atom, a haloalkyl group, or a hydrocarbon group. Ｘ１ The halogen atom represented by R is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. Ｘ１The haloalkyl group represented by is preferably a haloalkyl group having 1 to 10 carbon atoms, more preferably a haloalkyl group having 1 to 5 carbon atoms. The haloalkyl group may be an alkyl group in which some of the hydrogen atoms have been substituted with halogen atoms, or may be a perhaloalkyl group in which all of the hydrogen atoms have been substituted with halogen atoms. The haloalkyl group is preferably a fluoroalkyl group. R Ｘ１ Examples of the hydrocarbon group represented by R include an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 5 to 15 carbon atoms), and an alkenyl group (preferably having 2 to 10 carbon atoms). Ｘ１ The hydrocarbon group and haloalkyl group represented by R may have a substituent. Ｘ１ The hydrocarbon group and haloalkyl group represented by ２ When it contains -, -CH ２ At least one of - is -O-, -CO-, -S- and -SO ２ - may be replaced with at least one selected from the group consisting of

[0089] In formula (Pa2), n1 represents an integer of 1 or more and 5 or less, and preferably represents an integer of 1 or more and 4 or less.

[0090] In formula (Pa2), m1 represents an integer of 0 or more and 4 or less, and preferably represents an integer of 0 or more and 3 or less.

[0091] When the resin (A) contains a repeating unit having an acid group, the content of the repeating unit having an acid group is preferably 10 mol% or more, more preferably 15 mol% or more, based on the total repeating units in the resin (A), and the content of the repeating unit having an acid group is preferably 90 mol% or less, more preferably 80 mol% or less, based on the total repeating units in the resin (A).

[0092] (Repeating units having neither an acid-decomposable group nor an acid group, and having a fluorine atom, a bromine atom, or an iodine atom) In addition to the above-mentioned <repeating units having an acid-decomposable group> and <repeating units having an acid group>, the resin (A) may have 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 (hereinafter also referred to as unit X). The <repeating units 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 preferably different from other types of repeating units belonging to Group A, such as the <repeating units having a lactone group, a sultone group, or a carbonate group> and the <repeating units having a photoacid-generating group> described below.

[0093] The unit X is preferably a repeating unit represented by formula (C).

[0094]

[0095] L ５ represents a single bond or an ester group. ９ represents a hydrogen atom or an alkyl group which may have a fluorine atom or an iodine atom. １０ represents a hydrogen atom, an alkyl group which may have a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, an aryl group which may have a fluorine atom or an iodine atom, or a group combining these. Specific examples of repeating units having a fluorine atom or an iodine atom include the repeating units described in paragraphs

[0116] to

[0117] of WO 2022 / 024928. The above descriptions are incorporated herein by reference.

[0096] The content of units X is preferably 0 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on all repeating units in resin (A), and the upper limit thereof is preferably 80 mol% or less, more preferably 70 mol% or less, based on all repeating units in resin (A).

[0097] Among the repeating units of the resin (A), the total content of repeating units having at least one of a fluorine atom, a bromine atom, and an iodine atom is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, and particularly preferably 40 mol% or more, based on the total repeating units of the resin (A). The upper limit is not particularly limited, but is, for example, 100 mol% or less, based on the total repeating units of the resin (A). Examples of repeating units having at least one of a fluorine atom, a bromine atom, and an iodine atom include repeating units having a fluorine atom, a bromine atom, or an iodine atom and an acid-decomposable group, repeating units having a fluorine atom, a bromine atom, or an iodine atom and an acid group, and repeating units having a fluorine atom, a bromine atom, or an iodine atom.

[0098] (Repeating unit having a lactone group, a sultone group, or a carbonate group) The 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 unit Y does not have a hydroxyl group or an acid group such as a hexafluoropropanol group.

[0099] The lactone group or sultone group may have a lactone structure or a sultone structure. The lactone structure or sultone structure is preferably a 5- to 7-membered cyclic lactone structure or a 5- to 7-membered cyclic sultone structure. Among these, a 5- to 7-membered cyclic lactone structure to which another ring structure is fused in the form of a bicyclo or spiro structure, or a 5- to 7-membered cyclic sultone structure to which another ring structure is fused in the form of a bicyclo or spiro structure, is more preferred. Resin (A) preferably has a repeating unit having a lactone group, sultone group, or carbonate group obtained by removing one or more hydrogen atoms from a ring atom of a lactone structure represented by any one of formulas (LC1-1) to (LC1-22) below, a sultone structure represented by any one of formulas (SL1-1) to (SL1-3) below, or a cyclic carbonate ester structure represented by any one of formulas (CC1-1) to (CC1-2) below, and the lactone group, sultone group, or carbonate group may be directly bonded to the main chain. For example, ring atoms of a lactone group, a sultone group, or a carbonate group may constitute the main chain of the resin (A). The lactone group, the sultone group, and the carbonate group may have a substituent.

[0100] R in the following structural formula Ｌ represents a substituent. Ｌ If there are multiple R Ｌ may be the same or different. Ｌ Examples of R include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 10 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a carboxyl group, a halogen atom, a cyano group, and an acid-decomposable group. e1 represents an integer of 0 to 4. When multiple e1s are present, the multiple e1s may be the same or different. When e1 is 2 or more, the multiple R Ｌ may be the same or different, and multiple R Ｌ They may be bonded to each other to form a ring.

[0101]

[0102] Examples of repeating units having a lactone group, a sultone group, or a carbonate group include repeating units represented by the following formula (AI-2).

[0103]

[0104] In formula (AI-2), Rb ０ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. ０ The alkyl group of Rb may have a substituent. ０ Preferred substituents that the alkyl group of Rb may have include a hydroxyl group and a halogen atom. ０ Examples of the halogen atom in Rb include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. ０ is preferably a hydrogen atom or a methyl group. Ab represents 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 divalent linking group formed by combining these. Among these, Ab is preferably a single bond or -Ab １ -CO ２ A linking group represented by - is preferred. １ is a linear or branched alkylene group, or a monocyclic or polycyclic cycloalkylene group, and is preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group, or a norbornylene group. V is a group obtained by removing one hydrogen atom from a ring member atom of a lactone structure represented by any of formulas (LC1-1) to (LC1-22), a group obtained by removing one hydrogen atom from a ring member atom of a sultone structure represented by any of formulas (SL1-1) to (SL1-3), or a group obtained by removing one hydrogen atom from a ring member atom of a cyclic carbonate structure represented by any of formulas (CC1-1) to (CC1-2).

[0105] When optical isomers exist in the repeating unit having a lactone group or a sultone group, any optical isomer may be used. One optical isomer may be used alone, or multiple optical isomers may be used in combination. When one optical isomer is primarily used, its optical purity (ee) is preferably 90 or more, more preferably 95 or more.

[0106] The carbonate group is preferably a cyclic carbonate ester group. For repeating units having a cyclic carbonate ester group, see, for example, paragraphs

[0127] to

[0133] of WO 2022 / 024928. The above description is incorporated herein by reference.

[0107] When the resin (A) contains the unit Y, the content of the unit Y is preferably 1 mol % or more, more preferably 10 mol % or more, based on all repeating units in the resin (A), and the upper limit thereof is preferably 80 mol % or less, more preferably 70 mol % or less, based on all repeating units in the resin (A).

[0108] (Repeating unit having a photoacid generating group) The resin (A) may contain a repeating unit having a group that generates an acid upon irradiation with actinic rays or radiation (also referred to as a "photoacid generating group"). Examples of the repeating unit having a photoacid generating group include a repeating unit represented by formula (4).

[0109]

[0110] R ４１ represents a hydrogen atom or a methyl group. ４１ represents a single bond or a divalent linking group. ４２ represents a divalent linking group. ４０ represents a structural moiety that decomposes upon irradiation with actinic rays or radiation to generate an acid in the side chain.

[0111] L ４１ represents a single bond or a divalent linking group, and preferably represents a single bond or an ester bond (—COO—).

[0112] L ４２ represents an alkylene group, a cycloalkylene group, an arylene group, —O—, —CO—, —S—, —SO—, —SO ２Preferably, the linking group is at least one selected from the group consisting of - and -NR-. R represents a hydrogen atom or an organic group (preferably an organic group having 1 to 10 carbon atoms, such as an alkyl group, a cycloalkyl group, or an aryl group). The alkylene group may be either linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but preferably 1 to 10. The cycloalkylene group may be a monocyclic cycloalkylene group or a polycyclic cycloalkylene group. The number of carbon atoms in the cycloalkylene group is not particularly limited, but preferably 3 to 20, more preferably 5 to 15. The number of carbon atoms in the arylene group is not particularly limited, but preferably 6 to 20, more preferably 6 to 10. The alkylene group, cycloalkylene group, and arylene group may have a substituent, and examples of the substituent include the substituent T described above.

[0113] R ４０ is preferably a group represented by the following formula (S4-1).

[0114]

[0115] In formula (S4-1), Q － represents an acid residue, M ＋ represents a cation. * represents L ４１ The bond position of the acid residue is a group formed by dissociating a proton from an acid. － is a carboxylate anion group (COO － ), sulfonate anion group (SO ３ － ), or a sulfonamide group (N － -SO ２ R Ｎ１ It is expressed as: R Ｎ１ represents an organic group, and examples thereof include organic groups having 1 to 10 carbon atoms, and an alkyl group, a fluoroalkyl group, or an aryl group is preferred. ) is preferred, and a sulfonate anion group is more preferred. M ＋ The explanation, specific examples and preferred ranges for M in the explanation of the photoacid generator are ＋ is the same as

[0116] Specific examples of repeating units having a photoacid generating group include the repeating units described in

[0094] to

[0105] of JP 2014-041327 A, the repeating unit described in

[0094] of WO 2018 / 193954 A, and the repeating unit described in

[0138] of WO 2022 / 024928 A. The above descriptions are incorporated herein by reference.

[0117] Examples of the repeating unit represented by formula (4) include the repeating units described in paragraphs

[0094] to

[0105] of JP 2014-041327 A and the repeating unit described in paragraph

[0094] of WO 2018 / 193954 A.

[0118] When the resin (A) contains a repeating unit having a photoacid generating group, the content of the repeating unit having a photoacid generating group is preferably 1 mol% or more, more preferably 3 mol% or more, and particularly preferably 5 mol% or more, based on the total repeating units in the resin (A).Furthermore, the content of the repeating unit having a photoacid generating group is preferably 50 mol% or less, more preferably 30 mol% or less, and particularly preferably 20 mol% or less, based on the total repeating units in the resin (A).It is also preferable that the resin (A) does not contain a repeating unit having a photoacid generating group.

[0119] (Repeating unit represented by formula (V-1) or formula (V-2)) The resin (A) may have a repeating unit represented by the following formula (V-1) or formula (V-2). The repeating units represented by the following formula (V-1) and formula (V-2) are preferably repeating units different from the above-mentioned repeating units.

[0120]

[0121] In the formula, R ６ and R ７each independently represents 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 an alkyl group or a fluorinated alkyl group having 1 to 6 carbon atoms), or a carboxyl group. As the alkyl group, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms is preferred. ３ represents an integer of 0 to 6. ４ represents an integer of 0 to 4. ４ is a methylene group, an oxygen atom, or a sulfur atom. Examples of repeating units represented by formula (V-1) or (V-2) are shown below. Examples of repeating units represented by formula (V-1) or (V-2) include the repeating units described in paragraph

[0100] of WO 2018 / 193954.

[0122] (Repeating Unit for Reducing Mobility of Main Chain) Resin (A) preferably has a high glass transition temperature (Tg) in order to suppress excessive diffusion of generated acid or pattern collapse during development. Tg is preferably higher than 90°C, more preferably higher than 100°C, even more preferably higher than 110°C, and particularly preferably higher than 125°C. In order to achieve an excellent dissolution rate in a developer, Tg is preferably 400°C or lower, more preferably 350°C or lower. In this specification, the glass transition temperature (Tg) of a polymer such as resin (A) (hereinafter referred to as "Tg of repeating unit") is calculated by the following method. First, the Tg of a homopolymer consisting of only each repeating unit contained in the polymer is calculated using the Bicerano method. Next, the mass proportion (%) of each repeating unit relative to all repeating units in the polymer is calculated. Next, the Tg at each mass ratio is calculated using the Fox formula (described in Materials Letters 62 (2008) 3152, etc.), and the sum of these values ​​is used to determine 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 polymer property estimation software MDL Polymer (MDL Information Systems, Inc.).

[0123] For the repeating units for reducing the mobility of the main chain, the contents of paragraphs

[0144] to

[0160] of WO 2022 / 024928 are incorporated herein by reference.

[0124] (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) The resin (A) may have 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. Examples of the repeating unit having a lactone group, a sultone group, or a carbonate group contained in the resin (A) include the repeating units described above in <Repeating unit having a lactone group, a sultone group, or a carbonate group>. The preferred content is also as described above in <Repeating unit having a lactone group, a sultone group, or a carbonate group>.

[0125] The resin (A) may have a repeating unit having a hydroxyl group or a cyano group. This improves substrate adhesion. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having a saturated hydrocarbon group having a hydroxyl group or a cyano group (substituted with a hydroxyl group or a cyano group). It may also be a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The 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 2014-098921 A.

[0126] The resin (A) may have a repeating unit having an alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bissulfonylimide group, and an aliphatic alcohol group (e.g., a hexafluoroisopropanol group) substituted at the α-position with an electron-withdrawing group, with a carboxyl group being preferred. When the resin (A) contains a repeating unit having an alkali-soluble group, the resolution in contact hole applications is improved. Examples of repeating units having an alkali-soluble group include those described in paragraphs

[0085] and

[0086] of JP 2014-098921 A.

[0127] (Repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability) Resin (A) may have a repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability. This can reduce elution of low molecular weight components from the resist film into the immersion liquid during immersion exposure. Examples of repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposability include repeating units derived from 1-adamantyl(meth)acrylate, diamantyl(meth)acrylate, tricyclodecanyl(meth)acrylate, or cyclohexyl(meth)acrylate.

[0128] (Repeating Unit Represented by Formula (III) Having Neither a Hydroxyl Group nor a Cyano Group) The resin (A) may have a repeating unit represented by formula (III) having neither a hydroxyl group nor a cyano group.

[0129]

[0130] In formula (III), R ５ 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 represents a group. ２ represents a hydrogen atom, an alkyl group, or an acyl group. Examples of the repeating unit represented by formula (III) that does not have either a hydroxyl group or a cyano group include those described in paragraphs

[0087] to

[0094] of JP 2014-098921 A.

[0131] (Other Repeating Units) Furthermore, the resin (A) may have a repeating unit other than the repeating units described above. For example, the resin (A) may have a repeating unit selected from the group consisting of a repeating unit having an oxathiane ring group, a repeating unit having an oxazolone ring group, a repeating unit having a dioxane ring group, and a repeating unit having a hydantoin ring group.

[0132] In addition to the repeating structural units described above, the resin (A) may have various repeating structural units for the purpose of adjusting dry etching resistance, suitability for a standard developer, substrate adhesion, resist profile, resolution, heat resistance, sensitivity, and the like.

[0133] As the resin (A), particularly when the resist composition is used as an ArF actinic ray-sensitive or radiation-sensitive resin composition, it is preferable that all of the repeating units are composed of repeating units derived from a compound having an ethylenically unsaturated bond.In particular, it is also preferable 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, any of those in which all of the repeating units are methacrylate repeating units, all of the repeating units are acrylate repeating units, or all of the repeating units are a combination of methacrylate repeating units and acrylate repeating units can be used, and it is preferable that the acrylate repeating units account for 50 mol% or less of the total repeating units.

[0134] Resin (A) can be synthesized according to a conventional method (e.g., radical polymerization). The weight average molecular weight (Mw) of resin (A), as measured by GPC in terms of polystyrene, is preferably 30,000 or less, more preferably 1,000 to 30,000, even more preferably 3,000 to 30,000, and particularly preferably 5,000 to 15,000. The dispersity (molecular weight distribution, Mw / Mn) of resin (A) is preferably 1.0 to 5, more preferably 1.0 to 3, even more preferably 1.1 to 2.0, and particularly preferably 1.1 to 1.5. The smaller the dispersity, the better the resolution and resist shape, and furthermore, the smoother the sidewalls of the resist pattern and the better the roughness.

[0135] The content of resin (A) in the resist composition is preferably 30.0 to 99.9 mass%, more preferably 40.0 to 99.9 mass%, and even more preferably 60.0 to 90.0 mass%, based on the total solids content of the resist composition. Resin (A) may be used alone, or two or more types may be used. When two or more types are used, it is preferable that the total content falls within the above-mentioned suitable content range.

[0136] <Salt Compound (B)> The resist composition contains a salt compound (B) that generates a Lewis acid capable of decomposing an acid-decomposable group upon irradiation with actinic rays or radiation (hereinafter, also simply referred to as "salt compound (B)" or "photoacid generator (B)").

[0137] The photoacid generator (B) may be in the form of a low molecular weight compound or may be incorporated into a polymer. Furthermore, both the low molecular weight compound and the polymer 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 not particularly limited, but is preferably 100 to 3,000, more preferably 150 to 2,500, and even more preferably 200 to 2,000. When the photoacid generator (B) is incorporated into a polymer, it may be incorporated into the resin (A) or into a resin different from the resin (A). When the resin (A) does not contain the repeating unit having a photoacid-generating group described above, the resist composition preferably contains a photoacid generator that is a compound different from the resin (A). When the resin (A) contains a repeating unit having a photoacid-generating group, the resist composition may or may not contain a separate photoacid generator. The photoacid generator is preferably in the form of a low molecular weight compound.

[0138] The term "Lewis acid" as used herein refers to an acid that accepts an electron pair, rather than an acid that donates a proton (Brønsted acid). Whether or not a generated acid is a Brønsted acid as used herein can be confirmed by identifying the structure of the generated acid using methods such as NMR (nuclear magnetic resonance) and LC / MS (liquid chromatography mass spectrometry).

[0139] In this specification, the term "Lewis acid capable of decomposing an acid-decomposable group" refers to a Lewis acid that decomposes 20% or more of the acid-decomposable groups (groups in which carboxy groups are protected with cyclopentylmethyl groups) in compound (Q) when the following compound (Q) is dissolved in toluene to a concentration of 0.33 M, 0.1 eq of a Lewis acid compound is added to the solution, and the mixture is heated at 90°C for 90 minutes (i.e., the cyclopentylmethyl groups, which are protecting groups, are deprotected to produce methacrylic acid). The decomposition rate of the acid-decomposable groups in compound (Q) was measured using deuterated DMSO (deuterated dimethyl sulfoxide) as a deuterated solvent. １ This can be done by H-NMR (nuclear magnetic resonance) measurement.

[0140]

[0141] The Lewis acid compound refers to a Lewis acid compound that is generated by irradiating a salt compound that generates a Lewis acid when irradiated with actinic rays or radiation.

[0142] In addition, in this specification, "a salt compound that generates a Lewis acid when irradiated with actinic rays or radiation" refers to a salt compound that generates 30 mol% or more of Lewis acid relative to the amount of the salt compound, as calculated by the following procedure. 1. A salt compound is added at 0.3 mmol / g to a parahydroxystyrene (PHS) homopolymer (VP-2500 (manufactured by Nippon Soda Co., Ltd.)) and dissolved in a solvent (propylene glycol monomethyl ether (PGME) / propylene glycol monomethyl ether acetate (PGMEA) = 1.1 (mass ratio)) to prepare a solution with a solids concentration of 3 mass%. The solids refer to components other than the solvent. 2. This solution is applied to a silicon wafer and dried by heating at 90°C to form a resist film with a thickness of 60 nm. 3. EB exposure (2000 kGy) is performed on the entire surface. 4. A 10 cm 2 portion of the exposed film is ２ The resulting solution is extracted with DMSO (2 ml) and subjected to HPLC analysis. The amount of Lewis acid generated is determined by comparing the unexposed sample with the 2000 kGy exposed sample. 5. The amount of Lewis acid generated relative to the amount of salt compound added is calculated.

[0143] The HPLC measurement conditions are as follows. 1 mL of DMSO was added to 1 mg of substrate samples coated with a resist film (for each of "unexposed sample" and "2000 kGy exposed sample") (1.3 cm x 0.8 cm x 9 sheets) or a standard sample, and ultrasonic waves were applied at 25°C for 15 minutes. After thorough mixing, HPLC measurement was performed under the following conditions. Apparatus: Prominence (Shimadzu Corporation), Column: Mightysil RP-18 (4.6 mmφ x 250 mm), Solution A: acetonitrile, Solution B: water (0.1 vol% acetic acid + 0.1 vol% triethylamine), Flow rate: 1.0 mL / min, A conc. : 5% (0 min) → 100% (28 min) → 100% (40 min) → 5% (40.1 min) → 5% (50 min), Column oven: 40°C, Detector: PDA, Injection volume: 10 μL

[0144] Lewis acid generation amount (mol %)=(1−(area of ​​salt compound in exposed film / area of ​​salt compound in unexposed film)×100

[0145] The salt compound (B) generates the Lewis acid by decomposing at least one of an anion and a cation in the salt compound (B) upon irradiation with actinic rays or radiation. The salt compound (B) is preferably a salt compound that generates the Lewis acid by decomposing an anion in the salt compound (B) upon irradiation with actinic rays or radiation.

[0146] From the viewpoint of improving the effects of the present invention, the salt compound (B) preferably has at least one iodine atom on the anion. The number of iodine atoms is preferably 2 to 20, more preferably 3 to 10.

[0147] From the viewpoint of improving the effects of the present invention, the salt compound (B) preferably has an anion containing a Group 13 element or a Group 14 element, more preferably has an anion containing boron, silicon, or aluminum, and further preferably has an anion containing boron or silicon.

[0148] The photoacid generator (B) is Ｂ ＋ X Ｂ－ It is preferable that the compound is a compound represented by the formula:

[0149] "Y Ｂ ＋ X Ｂ － In the compound represented by the formula ", Y Ｂ ＋ represents a cation, and the valence of the cation may be monovalent or divalent or more. The cation is not particularly limited, and may be a cation that does not decompose when irradiated with actinic rays or radiation, or may be a cation that decomposes when irradiated with actinic rays or radiation. Ｂ ＋ Preferably, represents an organic cation.

[0150] Examples of cations that do not decompose when irradiated with actinic rays or radiation include alkali metal cations, ammonium cations, pyridinium cations, imidazolium cations, phosphonium cations, and carbocations.

[0151] Examples of the alkali metal cation include sodium cation, lithium cation, and potassium cation.

[0152] The ammonium cation is preferably a cation represented by the following general formula (A1).

[0153]

[0154] In general formula (A1), R ａ１ ~R ａ４ R each independently represents an alkyl group or an alkoxy group. ａ１ ~R ａ４ The alkyl group represented by R is preferably a linear or branched alkyl group having 1 to 8 carbon atoms, more preferably a methyl group, an ethyl group, or a butyl group, and even more preferably a methyl group. ａ１ ~R ａ４ The alkoxy group represented by is not particularly limited, but is preferably a straight or branched alkoxy group having 1 to 8 carbon atoms, such as a methoxy group.

[0155] R ａ１ ~R ａ４ may further have a substituent.

[0156] R ａ１ ~R ａ４ are preferably all alkyl groups having 1 to 4 carbon atoms, and more preferably all methyl groups.

[0157] The pyridinium cation is preferably a cation represented by the following general formula (A2).

[0158]

[0159] In general formula (A2), R ａ５ represents a hydrogen atom, an alkyl group, or an alkynyl group. ａ６ represents an alkyl group or an alkynyl group. p1 represents an integer of 0 to 5. When p1 represents an integer of 2 to 5, a plurality of R ａ６ may be the same or different.

[0160] R ａ５ and R ａ６ The alkyl group represented by is R ａ１ ~R ａ４ and R ａ５ and R ａ６ The alkynyl group represented by the formula (I) includes an alkynyl group having 2 to 6 carbon atoms.

[0161] R ａ５ and R ａ６ may further have a substituent.

[0162] R ａ５ is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably a methyl group. ａ６ is preferably an alkyl group having 1 to 4 carbon atoms.

[0163] p1 represents an integer of 0 to 5, preferably an integer of 0 to 2, and more preferably 0.

[0164] The imidazolium cation is preferably a cation represented by the following general formula (A3).

[0165]

[0166] In general formula (A3), R ａ７ and R ａ８ R each independently represents a hydrogen atom, an alkyl group, or an alkoxy group. ａ９ represents an alkyl group or an alkoxy group. p2 represents an integer of 0 to 3. When p2 represents an integer of 2 or 3, a plurality of R ａ９ may be the same or different.

[0167] R ａ７ ~R ａ９ The alkyl group and alkoxy group represented by R in the above general formula (A1) are ａ１ ~R ａ４ The preferred examples are also the same.

[0168] R ａ７ ~R ａ９ may further have a substituent.

[0169] R ａ７ and R ａ８ is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably a methyl group. ａ９ is preferably an alkyl group having 1 to 4 carbon atoms.

[0170] p2 represents an integer of 0 to 4, preferably an integer of 0 to 2, and more preferably 0.

[0171] The phosphonium cation is preferably a cation represented by the following general formula (A4).

[0172]

[0173] In general formula (A4), R ａ１０ ~R ａ１３ R each independently represents an alkyl group or an alkoxy group. ａ１０ ~R ａ１３ The alkyl group and alkoxy group represented by R in the above general formula (A1) are ａ１ ~R ａ４ Examples of the alkyl group and alkoxy group include those represented by the following formula:

[0174] R ａ１０ ~R ａ１３may further have a substituent.

[0175] R ａ１０ ~R ａ１３ are preferably all alkyl groups having 1 to 8 carbon atoms, and more preferably all methyl groups.

[0176] Examples of the cation that decomposes upon irradiation with actinic rays or radiation include sulfonium cations and iodonium cations. Specific examples thereof include, for example, a cation represented by the following formula (ZaI) (hereinafter also referred to as "cation (ZaI)") or a cation represented by the following formula (ZaII) (hereinafter also referred to as "cation (ZaII)"):

[0177]

[0178] In the above formula (ZaI), R ２０１ , R ２０２ , and R ２０３ R each independently represents an organic group. ２０１ , R ２０２ , and R ２０３ The number of carbon atoms in the organic group represented by R is preferably 1 to 30, and more preferably 1 to 20. ２０１ ~R ２０３ Two of these may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ２０１ ~R ２０３ Examples of groups formed by combining two of these include alkylene groups (e.g., butylene and pentylene groups) and -CH ２ -CH ２ -O-CH ２ -CH ２ - are some examples.

[0179] Suitable embodiments of the cation represented by formula (ZaI) include cation (ZaI-1), cation (ZaI-2), cation (ZaI-3b), and cation (ZaI-4b) described below.

[0180] First, the cation (ZaI-1) will be described. The cation (ZaI-1) is R in the above formula (ZaI). ２０１ ~R ２０３is an arylsulfonium cation, in which at least one of R is an aryl group. ２０１ ~R ２０３ may all be aryl groups, or R ２０１ ~R ２０３ A part of R may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group. ２０１ ~R ２０３ is an aryl group, and R ２０１ ~R ２０３ The remaining two of R may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ２０１ ~R ２０３ Examples of groups formed by combining two of the above include alkylene groups in which one or more methylene groups may be substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and / or a carbonyl group (e.g., butylene group, pentylene group, and —CH ２ -CH ２ -O-CH ２ -CH ２ The arylsulfonium cations include triarylsulfonium cations, diarylalkylsulfonium cations, aryldialkylsulfonium cations, diarylcycloalkylsulfonium cations, and aryldicycloalkylsulfonium cations.

[0181] The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of heterocyclic structures include pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, 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 contained in the arylsulfonium cation is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, or a cyclohexyl group.

[0182] R ２０１ ~R ２０３ Preferred substituents that the aryl group, alkyl group, and cycloalkyl group may have include alkyl groups (e.g., having 1 to 15 carbon atoms), cycloalkyl groups (e.g., having 3 to 15 carbon atoms), aryl groups (e.g., having 6 to 14 carbon atoms), alkoxy groups (e.g., having 1 to 15 carbon atoms), cycloalkylalkoxy groups (e.g., having 1 to 15 carbon atoms), halogen atoms (e.g., fluorine and iodine), hydroxyl groups, carboxyl groups, ester groups, sulfinyl groups, sulfonyl groups, alkylthio groups, and phenylthio groups. The above substituents may further have substituents if possible, and it is also preferred that the alkyl group has a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group. It is also preferred that the above substituents form an acid-decomposable group in any combination. Note that the acid-decomposable group is intended to be a group that decomposes under the action of acid to generate a polar group, and is preferably a structure in which the polar group is protected with a group that leaves under the action of acid. The above polar groups and leaving groups are as described above.

[0183] Next, the cation (ZaI-2) will be described. The cation (ZaI-2) is a cation represented by the formula (ZaI) R ２０１ ~R ２０３ are each independently a cation representing an organic group that does not have an aromatic ring. The aromatic ring also includes an aromatic ring containing a heteroatom. ２０１ ~R ２０３ The number of carbon atoms of the organic group not having an aromatic ring as R is preferably 1 to 30, and more preferably 1 to 20. ２０１ ~R ２０３ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and still more preferably a linear or branched 2-oxoalkyl group.

[0184] R ２０１ ~R ２０３ Examples of the alkyl group and cycloalkyl group in R include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl groups), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl groups). ２０１ ~R ２０３ may be further substituted with a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. ２０１ ~R ２０３ It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0185] Next, the cation (ZaI-3b) will be described. The cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).

[0186]

[0187] In formula (ZaI-3b), R １ｃ ~R ５ｃR each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group. ６ｃ and R ７ｃ R each independently represents a hydrogen atom, an alkyl group (for example, a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group. ｘ and R ｙ R each independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group. １ｃ ~R ７ｃ , and R ｘ and R ｙ It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0188] R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ , R ５ｃ and R ｘ , and R ｘ and R ｙ may be bonded to each other to form a ring, and each of these rings may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the ring include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterocycles, and polycyclic fused rings formed by combining two or more of these rings. Examples of the ring include 3- to 10-membered rings, preferably 4- to 8-membered rings, and more preferably 5- or 6-membered rings.

[0189] R １ｃ ~R ５ｃ Two or more of the following, R ６ｃ and R ７ｃ , and R ｘ and R ｙExamples of the group formed by bonding of R include alkylene groups such as butylene and pentylene. A methylene group in this alkylene group may be substituted with a heteroatom such as an oxygen atom. ５ｃ and R ６ｃ , and R ５ｃ and R ｘ The group formed by bonding is preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group.

[0190] R １ｃ ~R ５ｃ , R ６ｃ , R ７ｃ , R ｘ , R ｙ , and R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ , R ５ｃ and R ｘ , and R ｘ and R ｙ The ring formed by bonding together may have a substituent.

[0191] Next, the cation (ZaI-4b) will be described. The cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).

[0192]

[0193] In formula (ZaI-4b), l represents an integer of 0 to 2, and r represents an integer of 0 to 8. １３ represents a hydrogen atom, a halogen atom (for example, a fluorine atom or an iodine atom), a hydroxyl group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a group containing a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent. R １４represents a hydroxyl group, a halogen atom (for example, a fluorine atom or an iodine atom), an alkyl group, a halogenated alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group containing a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent. R １４ When a plurality of R are present, each independently represents the above group such as a hydroxyl group. １５ each independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. １５ may be bonded to each other to form a ring. １５ When two R are bonded to each other to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom. １５ are preferably alkylene groups and bonded to each other to form a ring structure. １５ The ring formed by bonding together may have a substituent.

[0194] In formula (ZaI-4b), R １３ , R １４ , and R １５ The alkyl group in R may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1 to 10. The alkyl group is preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like. １３ ~R １５ , and R ｘ and R ｙ It is also preferred that each of the substituents independently form an acid-decomposable group by any combination of the substituents.

[0195]

[0196] In formula (ZaII), R ２０４ and R ２０５ R each independently represents an aryl group, an alkyl group, or a cycloalkyl group. ２０４ and R ２０５The aryl group in R is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. ２０４ and R ２０５ The aryl group in R may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. ２０４ and R ２０５ The alkyl group and cycloalkyl group are preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, or pentyl), or a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, or norbornyl).

[0197] R ２０４ and R ２０５ The aryl group, alkyl group, and cycloalkyl group in R may each independently have a substituent. ２０４ and R ２０５ Examples of the substituents that the aryl group, alkyl group, and cycloalkyl group may have include alkyl groups (e.g., having 1 to 15 carbon atoms), cycloalkyl groups (e.g., having 3 to 15 carbon atoms), aryl groups (e.g., having 6 to 15 carbon atoms), alkoxy groups (e.g., having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups. ２０４ and R ２０５ It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0198] Y Ｂ ＋ is preferably a cation that decomposes upon irradiation with actinic rays or radiation, more preferably a sulfonium cation or an iodonium cation, and even more preferably a triarylsulfonium cation or a diaryliodonium cation.

[0199] "Y Ｂ ＋ X Ｂ －In the compound represented by the formula "X Ｂ － represents an organic anion. Examples of the organic anion include monovalent and divalent or higher valent organic anions.

[0200] X Ｂ － The number of iodine atoms is preferably 2 to 20, and more preferably 3 to 10.

[0201] X Ｂ － preferably contains a Group 13 element or a Group 14 element, more preferably contains boron, silicon, or aluminum, and further preferably contains boron or silicon.

[0202] The salt compound (B) is preferably an onium salt compound, and more preferably an onium salt compound represented by any one of the following general formulas (BI) to (BIII).

[0203]

[0204] In general formulas (BI) to (BIII), R １ ~R ３ R each independently represents an aromatic ring group. ４ ~R １０ R each independently represents an aromatic ring group. １ ~R ３ At least two of R ４ ~R ６ and at least two of R ７ ~R １０ At least two of X may be bonded to each other to form a ring structure. １ ~X ３ Each of Y independently represents a monovalent organic group. １ ＋ ~Y ３ ＋ each independently represents a cation.

[0205] In general formula (BI), R １ ~R ３ represents an aromatic ring group. １ ~R ３The aromatic ring in the aromatic ring group represented by the formula (I) includes an aromatic hydrocarbon ring or an aromatic heterocyclic ring.

[0206] The aromatic hydrocarbon ring may be a monocyclic ring or a polycyclic ring. The number of ring atoms is preferably 6 to 15, more preferably 6 to 10. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring. Of these, a benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.

[0207] The aromatic heterocycle may be a monocycle or a polycycle. The number of ring atoms is preferably 5 to 15. Examples of the heterocycle having aromaticity include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, an imidazole ring, a triazole ring, a pyridine ring, an indole ring, a benzodiazole ring, a benzotriazole ring, and a carbazole ring.

[0208] R １ ~R ３ preferably each independently represents a benzene ring, an imidazole ring, a triazole ring, a benzotriazole ring, a pyridine ring, a pyrimidine ring, or a triazine ring, more preferably represents a benzene ring, an imidazole ring, a triazole ring, or a benzotriazole ring, and still more preferably represents a benzene ring.

[0209] R １ ~R ３ may have a substituent, and among them, it is preferable that R has an electron-withdrawing group. １ ~R ３ It is preferred that at least one of them has an electron-withdrawing group.

[0210] Examples of the electron-withdrawing group include a group selected from the group consisting of a halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), a halogenated hydrocarbon group, an alkoxycarbonyl group, an acyl group, an acyloxy group, a cyano group, a nitro group, and a heterocyclic group, or an aryl group substituted with a group selected from the above group. Among these, a halogen atom or a halogenated hydrocarbon group is preferred, a halogen atom is more preferred, a fluorine atom or an iodine atom is even more preferred, and an iodine atom is particularly preferred.

[0211] In general formulas (BII) to (BIII), R ４ ~R １０ R each independently represents an aromatic ring group. ４ ~R １０ The aromatic ring in the aromatic ring group represented by the above R １ ~R ３ Examples of aromatic rings include those in the aromatic ring group represented by R ４ ~R １０ preferably each independently represents a benzene ring, an imidazole ring, or a triazole ring, and more preferably represents a benzene ring.

[0212] R ４ ~R １０ may have a substituent, and among them, it is preferable that the group has an electron-withdrawing group. １ ~R ３ The preferred examples are also the same.

[0213] In general formulas (BI) to (BIII), X １ ~X ３ Each of X independently represents a monovalent organic group. １ ~X ３ The monovalent organic group represented by is not particularly limited, and examples thereof include the groups exemplified as organic group W below.

[0214] (Organic Group W) Examples of the organic group W include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a cycloalkynyl group, an aryl group, a heteroaryl group, an aralkyl group, a cyano group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an acyl group (an alkylcarbonyl group or an arylcarbonyl group), an acyloxy group (an alkylcarbonyloxy group or an arylcarbonyloxy group), a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an alkyl or arylsulfinyl group, an alkyl or arylsulfonyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, an aryl or heterocyclic azo group, a sulfonamide group, an imido group, an acylamino group, a carbamoyl group, and a lactone group.

[0215] The number of carbon atoms in the alkyl group exemplified as the organic group W is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6. The alkyl group may be either linear or branched. Examples of the alkyl group include linear or branched alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, and n-hexyl.

[0216] As the alkyl group moiety in the alkoxy group (including the alkoxy group moiety in a substituent containing an alkoxy group (for example, an alkoxycarbonyloxy group)) exemplified in the organic group W, the alkyl group moiety in the aralkyl group, the alkyl group moiety in the alkylcarbonyl group, the alkyl group moiety in the alkylcarbonyloxy group, the alkyl group moiety in the alkylthio group, the alkyl group moiety in the alkylsulfinyl group, and the alkyl group moiety in the alkylsulfonyl group, the above-mentioned alkyl groups are preferred.

[0217] Examples of the cycloalkyl group for the organic group W include monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, etc. The cycloalkyl group preferably has 5 to 20 carbon atoms, and more preferably 5 to 15 carbon atoms.

[0218] The alkenyl group exemplified as the organic group W may be either linear or branched. The number of carbon atoms in the alkenyl group is preferably 2 to 20. The number of carbon atoms in the cycloalkenyl group exemplified as the organic group W is preferably 5 to 20.

[0219] The alkynyl group exemplified as the organic group W may be either linear or branched. The number of carbon atoms in the alkynyl group is preferably 2 to 20. The number of carbon atoms in the cycloalkynyl group exemplified as the organic group W is preferably 5 to 20.

[0220] The aryl group exemplified in the organic group W may be either a monocyclic or polycyclic (for example, 2 to 6 rings, etc.) unless otherwise specified. The number of ring atoms in the aryl group is preferably 6 to 15, more preferably 6 to 10. The aryl group is preferably a phenyl group, a naphthyl group, or an anthryl group, and more preferably a phenyl group. Furthermore, among the groups exemplified in the organic group W, the aryl group moiety in a substituent containing an aryl group (for example, an aryloxy group) can be exemplified by the same examples as the aryl group exemplified in the organic group W.

[0221] The heteroaryl group exemplified as the organic group W may be either a monocyclic or polycyclic (e.g., 2 to 6 rings, etc.) unless otherwise specified. The number of heteroatoms contained in the heteroaryl group as ring atoms is, for example, 1 to 10. Examples of the heteroatom include a nitrogen atom, a sulfur atom, an oxygen atom, a selenium atom, a tellurium atom, a phosphorus atom, a silicon atom, and a boron atom. The number of ring atoms in the heteroaryl group is preferably 5 to 15.

[0222] The heterocycle exemplified in the organic group W is intended to be a ring containing a heteroatom as a ring member atom, and unless otherwise specified, may be either an aromatic heterocycle or an aliphatic heterocycle, and may be either a monocycle or a polycycle (e.g., 2 to 6 rings, etc.). The number of heteroatoms contained as ring members in the heterocycle is, for example, 1 to 10. Examples of the heteroatom include a nitrogen atom, a sulfur atom, an oxygen atom, a selenium atom, a tellurium atom, a phosphorus atom, a silicon atom, and a boron atom. The number of ring members in the heterocycle is preferably 5 to 15.

[0223] The lactone group exemplified as the organic group W is preferably a 5- to 7-membered lactone group, and more preferably a 5- to 7-membered lactone ring to which another ring structure is condensed in the form of a bicyclo structure or a spiro structure.

[0224] X １ ~X ３ The monovalent organic group represented by is preferably an alkyl group, an aryl group, an aryloxy group, or a heteroaryl group.

[0225] X １ ~X ３ The monovalent organic group represented by may further have a substituent, if possible. The substituent is preferably an electron-donating group such as a methoxy group, a methyl group, or a t-butyl group, and more preferably a methoxy group.

[0226] In general formulas (BI) to (BIII), Y １ ＋ ~Y ３ ＋ Each of Y independently represents a cation. １ ＋ ~Y ３ ＋ The cation represented by the above-mentioned Y Ｂ ＋ Among the cations represented by Y, cations corresponding to onium ions can be mentioned, and the same applies to preferred examples. １ ＋ ~Y ３ ＋is preferably a cation that decomposes upon irradiation with actinic rays or radiation, more preferably a sulfonium cation or an iodonium cation, and even more preferably a triarylsulfonium cation or a diaryliodonium cation.

[0227] The onium salt compounds represented by the above general formulas (BI) to (BIII) are more preferably onium salt compounds represented by the following general formulas (BI-2) to (BIII-2), respectively.

[0228]

[0229] In general formula (BI-2), R １ａ ~R ３ａ R each independently represents an electron-withdrawing group. １ｂ ~R ３ｂ each independently represents a substituent other than an electron-withdrawing group. c1 to c3 each independently represents an integer of 0 to 5, provided that at least one of c1 to c3 represents an integer of 1 or more. d1 to d3 each independently represents an integer of 0 to 5, provided that 0≦c1+d1≦5, 0≦c2+d2≦5, and 0≦c3+d3≦5 are satisfied. X １１ represents a monovalent organic group that is different from the other substituents linked to the boron atom. １ ＋ represents a cation. １ｂ ~R ３ｂ may be bonded to each other to form a ring structure, in which case R １ｂ ~R ３ｂ may be a single bond.

[0230] R １ａ ~R ３ａ each independently represents an electron-withdrawing group. Examples of the electron-withdrawing group include R １ ~R ３ The substituents that may be possessed by the group include electron-withdrawing groups, and preferred examples are also the same.

[0231] R １ｂ ~R ３ｂeach independently represents a substituent other than an electron-withdrawing group. Examples of the substituent other than an electron-withdrawing group include an alkyl group.

[0232] R １ｂ ~R ３ｂ The alkyl group represented by may be linear or branched, and is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably a methyl group.

[0233] c1 to c3 each independently represent an integer of 0 to 5. However, at least one of c1 to c3 represents an integer of 1 or greater. It is preferable that all of c1 to c3 represent an integer of 1 or greater, more preferably all of c1 to c3 represent an integer of 2 or greater, even more preferably all of c1 to c3 represent an integer of 3 or greater, particularly preferably all of c1 to c3 represent an integer of 4 or greater, and most preferably all of c1 to c3 represent 5.

[0234] d1 to d3 each independently represent an integer of 0 to 5, provided that 0≦c1+d1≦5, 0≦c2+d2≦5, and 0≦c3+d3≦5 are satisfied. d1 to d3 each preferably represent 0 or 1, and more preferably 0.

[0235] X １１ represents boron (B in general formula (BI-2)) － represents a monovalent organic group that is different from the other substituents connected to X. １１ As the organic group, the above-mentioned organic group W can be mentioned. １１ is different from other substituents attached to the boron. １１ can be a group different from the other substituents linked to boron in the organic group W.

[0236] In a preferred embodiment, for example, boron (B in general formula (BI-2)) － Of the four substituents bonded to X, three are the same and one (X １１ In such a compound, a structure in which the three substituents are different from each other (X １１) is assumed to be easily cleaved by irradiation with actinic rays or radiation. The same applies to the onium salt represented by general formula (BII-2) described below. For example, tris(pentafluorophenyl)borane, a Lewis acid, is detected by HPLC as described above.

[0237] Y in general formula (BI-2) １ ＋ represents Y in general formula (BI). １ ＋ The same applies to preferred examples.

[0238]

[0239] In general formula (BII-2), R ４ａ ~R ６ａ R each independently represents an electron-withdrawing group. ４ｂ ~R ６ｂ each independently represents a substituent other than an electron-withdrawing group. c4 to c6 each independently represent an integer of 0 to 5, provided that at least one of c4 to c6 represents an integer of 1 or more. d4 to d6 each independently represent an integer of 0 to 5, provided that 0≦c4+d4≦5, 0≦c5+d5≦5, and 0≦c6+d6≦5 are satisfied. X ２２ represents a monovalent organic group that is different from other substituents linked to boron. ２ ＋ represents a cation. ４ｂ ~R ６ｂ may be bonded to each other to form a ring structure, in which case R ４ｂ ~R ６ｂ may be a single bond.

[0240] R ４ａ ~R ６ａ each independently represents an electron-withdrawing group. Examples of the electron-withdrawing group include R ４ ~R ６ The substituents that may be possessed by the group include electron-withdrawing groups, and preferred examples are also the same.

[0241] R ４ｂ ~R ６ｂeach independently represents a substituent other than an electron-withdrawing group. Examples of the substituent other than an electron-withdrawing group include the above-mentioned R １ｂ ~R ３ｂ Examples of substituents other than electron-withdrawing groups include:

[0242] c4 to c6 each independently represent an integer of 0 to 5. However, at least one of c4 to c6 represents an integer of 1 or greater. It is preferable that all of c4 to c6 represent an integer of 1 or greater, more preferably all of c4 to c6 represent an integer of 2 or greater, even more preferably all of c4 to c6 represent an integer of 3 or greater, particularly preferably all of c4 to c6 represent an integer of 4 or greater, and most preferably all of c4 to c6 represent 5.

[0243] d4 to d6 each independently represent an integer of 0 to 5, provided that 0≦c4+d4≦5, 0≦c5+d5≦5, and 0≦c6+d6≦5 are satisfied. d4 to d6 preferably represent 0 or 1. X ２２ represents boron (B in general formula (BII-2) － represents a monovalent organic group that is different from the other substituents connected to X. ２２ As the organic group, the above-mentioned organic group W can be mentioned. ２２ is different from other substituents attached to the boron. ２２ can be a group different from the other substituents linked to boron in the organic group W.

[0244] Y in general formula (BII-2) ２ ＋ represents Y in general formula (BII). ２ ＋ The same applies to preferred examples.

[0245]

[0246] In general formula (BIII-2), R ７ａ ~R １０ａ R each independently represents an electron-withdrawing group. ７ｂ ~R １０ｂeach independently represents a substituent other than an electron-withdrawing group. c7 to c10 each independently represent an integer of 0 to 5. However, at least one of c7 to c10 represents an integer of 1 or more. d7 to d10 each independently represent an integer of 0 to 5. However, the following conditions are satisfied: 0≦c7+d7≦5, 0≦c8+d8≦5, 0≦c9+d9≦5, and 0≦c10+d10≦5. X ３３ represents a monovalent organic group that is different from other silicon-bonded substituents. ３ ＋ represents a cation. ７ｂ ~R １０ｂ may be bonded to each other to form a ring structure, in which case R ７ｂ ~R １０ｂ may be a single bond.

[0247] R ７ａ ~R １０ａ each independently represents an electron-withdrawing group. Examples of the electron-withdrawing group include R ７ ~R １０ The substituents that may be possessed by the group include electron-withdrawing groups, and preferred examples are also the same.

[0248] R ７ｂ ~R １０ｂ each independently represents a substituent other than an electron-withdrawing group. Examples of the substituent other than an electron-withdrawing group include the above-mentioned R １ｂ ~R ３ｂ Examples of substituents other than electron-withdrawing groups include:

[0249] c7 to c10 each independently represent an integer of 0 to 5. However, at least one of c7 to c10 represents an integer of 1 or greater. It is preferable that all of c7 to c10 represent an integer of 1 or greater, more preferably all of c7 to c10 represent an integer of 2 or greater, even more preferably all of c7 to c10 represent an integer of 3 or greater, particularly preferably all of c7 to c10 represent an integer of 4 or greater, and most preferably all of c7 to c10 represent 5.

[0250] d7 to d10 each independently represent an integer of 0 to 5, provided that 0≦c7+d7≦5, 0≦c8+d8≦5, 0≦c9+d9≦5, and 0≦c10+d10≦5 are satisfied. d7 to d10 each preferably represent 0 or 1, and more preferably 0.

[0251] X ３３ represents silicon (Si in general formula (BIII-2) － represents a monovalent organic group that is different from the other substituents connected to X. ３３ As the organic group, the above-mentioned organic group W can be mentioned. ３３ is different from other silicon-linked substituents. ３３ can be a group different from the other substituents bonded to silicon in the organic group W.

[0252] Y in general formula (BIII-2) ３ ＋ represents Y in general formula (BIII). ３ ＋ The same applies to preferred examples.

[0253] Examples of anions in the salt compound (B) are shown below, but the present invention is not limited to these. Me represents a methyl group.

[0254]

[0255]

[0256]

[0257]

[0258] Examples of cations in the salt compound (B) are shown below, but the present invention is not limited to these. Me represents a methyl group.

[0259]

[0260]

[0261]

[0262]

[0263]

[0264] The content of the salt compound (B) in the resist composition is not particularly limited, but is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 5.0% by mass or more, based on the total solid content of the resist composition. Furthermore, the content of the salt compound (B) 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, based on the total solid content of the resist composition. Only one type of salt compound (B) may be used, or two or more types may be used. When two or more types of salt compounds (B) are used, the total content thereof is preferably within the above-mentioned preferred content range.

[0265] <Photoacid Generator Other Than Salt Compound (B)> In addition to the salt compound (B), the resist composition may contain a compound (photoacid generator) that generates an acid upon irradiation with actinic rays or radiation. Examples of the photoacid generator include "M ＋ X － ", and it is preferably a compound that generates an organic acid upon exposure. Examples of the organic acid include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphorsulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, aralkyl carboxylic acids, etc.), carbonylsulfonylimido acids, bis(alkylsulfonyl)imido acids, and tris(alkylsulfonyl)methido acids.

[0266] "M ＋ X － In the compound represented by the formula ", M ＋ represents a cation, preferably an organic cation. The cation is not particularly limited. The cation may have a valence of 1 or 2 or more. The cation is preferably a cation represented by the above formula (ZaI) or a cation represented by the above formula (ZaII).

[0267] "M ＋ X － In the compound represented by the formula "X －represents an anion, preferably an organic anion. The anion is not particularly limited, and examples thereof include monovalent or divalent or higher anions. The anion is preferably an anion having a significantly low ability to cause a nucleophilic reaction, and more preferably a non-nucleophilic anion.

[0268] Examples of non-nucleophilic anions include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, camphorsulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, aralkyl carboxylate anions, etc.), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

[0269] 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 is preferably a linear or branched alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms. 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).

[0270] The aryl group in the aromatic sulfonate anion and aromatic carboxylate anion is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a tolyl group, and a naphthyl group.

[0271] The alkyl group, cycloalkyl group, and aryl group mentioned above may have a substituent. The substituent is not particularly limited, but examples thereof include a nitro group, a halogen atom such as a fluorine atom or a chlorine atom, a carboxyl group, a hydroxyl group, an amino group, a cyano group, an alkoxy group (preferably having 1 to 15 carbon atoms), an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 3 to 15 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably having 2 to 7 carbon atoms), an acyl group (preferably having 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), an alkylthio group (preferably having 1 to 15 carbon atoms), an alkylsulfonyl group (preferably having 1 to 15 carbon atoms), an alkyliminosulfonyl group (preferably having 1 to 15 carbon atoms), and an aryloxysulfonyl group (preferably having 6 to 20 carbon atoms).

[0272] The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 7 to 14 carbon atoms. Examples of the aralkyl group having 7 to 14 carbon atoms include a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylbutyl group.

[0273] An example of the sulfonylimide anion is a saccharin anion.

[0274] The alkyl group in the bis(alkylsulfonyl)imide anion and the tris(alkylsulfonyl)methide anion is preferably an alkyl group having 1 to 5 carbon atoms. Substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, and cycloalkylaryloxysulfonyl groups, with fluorine atoms or alkyl groups substituted with fluorine atoms being preferred. Furthermore, the alkyl groups in the bis(alkylsulfonyl)imide anion may be bonded to each other to form a ring structure, which increases the acid strength.

[0275] Other non-nucleophilic anions include, for example, phosphorus fluorides (e.g., PF ６－ ), boron fluorides (e.g., BF ４ － ), and antimony fluorides (e.g., SbF ６ － ) are listed.

[0276] Preferred non-nucleophilic anions include aliphatic sulfonate anions in which at least the α-position of the sulfonic acid is substituted with a fluorine atom, aromatic sulfonate anions substituted with a fluorine atom or a group having a fluorine atom, bis(alkylsulfonyl)imide anions in which an alkyl group is substituted with a fluorine atom, and tris(alkylsulfonyl)methide anions in which an alkyl group is substituted with a fluorine atom. Among these, perfluoroaliphatic sulfonate anions (preferably having 4 to 8 carbon atoms) and benzenesulfonate anions having a fluorine atom are more preferred, and nonafluorobutanesulfonate anions, perfluorooctanesulfonate anions, pentafluorobenzenesulfonate anions, and 3,5-bis(trifluoromethyl)benzenesulfonate anions are even more preferred.

[0277] The non-nucleophilic anion is also preferably an anion represented by the following formula (AN1).

[0278]

[0279] In formula (AN1), R １ and R ２ each independently represents a hydrogen atom or a substituent. The substituent is not particularly limited, but 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. Examples of groups that are not electron-withdrawing groups include, each independently, -R', -OH, -OR', -OCOR', -NH ２ , -NR' ２ , —NHR′, or —NHCOR′ is preferred, where R′ is a monovalent hydrocarbon group.

[0280] Examples of the monovalent hydrocarbon group represented by R' include monovalent linear or branched hydrocarbon groups such as alkyl groups such as methyl, ethyl, propyl, and butyl; alkenyl groups such as ethenyl, propenyl, and butenyl; alkynyl groups such as ethynyl, propynyl, and butynyl; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl; monovalent alicyclic hydrocarbon groups such as cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and norbornenyl; aryl groups such as phenyl, tolyl, xylyl, mesityl, naphthyl, methylnaphthyl, anthryl, and methylanthryl; and aralkyl groups such as benzyl, phenethyl, phenylpropyl, naphthylmethyl, and anthrylmethyl. Among these, R １ and R ２ are each independently preferably a hydrocarbon group (preferably a cycloalkyl group) or a hydrogen atom.

[0281] L represents a divalent linking group. When a plurality of L's are present, they may be the same or different. Examples of the divalent linking group include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -S-, -SO-, and -SO ２ Examples of the divalent linking group include -, an alkylene group (preferably having 1 to 6 carbon atoms), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), and a divalent linking group formed by combining a plurality of these groups. Among these, examples of the divalent linking group include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, and -SO ２ -, -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-, or -SO ２ - or -COO-alkylene group- is more preferred.

[0282] As L, for example, a group represented by the following formula (AN1-1) is preferable: ａ - (CR２ａ ２ ) Ｘ -Q-(CR ２ｂ ２ ) Ｙ -* ｂ (AN1-1)

[0283] In formula (AN1-1), * ａ is R in formula (AN1). ３ Represents the bonding position with * ｂ represents -C(R １ ) (R ２ X and Y each independently represent an integer of 0 to 10, preferably an integer of 0 to 3. R ２ａ and R ２ｂ R each independently represents a hydrogen atom or a substituent. ２ａ and R ２ｂ When there are multiple R ２ａ and R ２ｂ may be the same or different, provided that when Y is 1 or more, -C(R １ ) (R ２ )- and CR directly bonded ２ｂ ２ R in ２ｂ 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 -SO ２ -* Ｂ where X+Y in formula (AN1-1) is 1 or more, and R ２ａ and R ２ｂ are all hydrogen atoms, Q is * Ａ -O-CO-O-* Ｂ , * Ａ -CO-*Ｂ , * Ａ -O-CO-* Ｂ , * Ａ -O-* Ｂ , * Ａ -S-* Ｂ , or * Ａ -SO ２ -* Ｂ Represents. Ａ is R in formula (AN1). ３ represents the bonding position on the side, and * Ｂ represents -SO in formula (AN1). ３ － represents the bonding position on the side.

[0284] In formula (AN1), R ３ represents an organic group. The organic group is not particularly limited as long as it has one or more carbon atoms, and may be a linear group (for example, a linear alkyl group), a branched group (for example, a branched alkyl group such as a t-butyl 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 (such as an oxygen atom, a sulfur atom, and / or a nitrogen atom).

[0285] Among them, R ３is 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 having 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.). The heteroatom may be substituted for one or more of the carbon atoms forming the cyclic 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 these, the organic group having a cyclic structure is preferably a hydrocarbon group having a cyclic structure. The 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 (e.g., a cyclohexyl group) or polycyclic (e.g., an adamantyl group), and preferably has 5 to 12 carbon atoms. As the lactone group and sultone group, for example, a group in which one hydrogen atom has been removed from a ring atom constituting the lactone structure or sultone structure in any of the structures represented by the above-mentioned formulae (LC1-1) to (LC1-22) and the structures represented by the above-mentioned formulae (SL1-1) to (SL1-3) is preferred.

[0286] R ３ Preferably, R contains a halogen atom. ３ The halogen atom contained in is preferably a fluorine atom or an iodine atom, and more preferably an iodine atom. When the resist composition is used as an EUV resist, the number of halogen atoms is preferably as large as possible from the viewpoint of the efficiency of absorbing EUV light. When an iodine atom is contained, a structure in which the iodine atom is directly bonded to a carbon atom on an aromatic ring is preferred.

[0287] As the anion represented by formula (AN1), the anions described in

[0040] to

[0044] of JP-A-2018-155908 are also preferred.

[0288] The non-nucleophilic anion may be a benzenesulfonate anion, and is preferably a benzenesulfonate anion substituted with a branched alkyl group or a cycloalkyl group.

[0289] The non-nucleophilic anion is also preferably an anion represented by the following formula (AN2).

[0290]

[0291] In formula (AN2), o represents an integer of 1 to 3. p represents an integer of 0 to 10. q represents an integer of 0 to 10.

[0292] 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 atoms. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. The alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group. Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, and is preferably a fluorine atom or CF ３ It is more preferable that both Xf's are fluorine atoms.

[0293] R ４ and R ５ R each independently represents a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom. ４ and R ５ If there are multiple R ４ and R ５ may be the same or different. ４ and R ５ The alkyl group represented by the formula (I) preferably has 1 to 4 carbon atoms. The alkyl group may have a substituent. ４ and R ５ is preferably a hydrogen atom.

[0294] L represents a divalent linking group, and is defined the same as L in formula (AN1).

[0295] W represents an organic group containing a cyclic structure. Among these, a cyclic organic group is preferred. Examples of the cyclic organic group include an alicyclic group, an aryl group, and a heterocyclic group. The alicyclic group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include a monocyclic cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic group include a polycyclic cycloalkyl group such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Among these, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group, are preferred.

[0296] The aryl group may be monocyclic or polycyclic. Examples of the aryl group include a phenyl group, a naphthyl group, a phenanthryl group, and an anthryl group. The heterocyclic group may be monocyclic or polycyclic. In particular, a polycyclic heterocyclic group can further suppress the diffusion of acid. The heterocyclic group may or may not have aromaticity. Examples of heterocyclic rings having aromaticity include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and a pyridine ring. Examples of heterocyclic rings having no aromaticity include 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.

[0297] The cyclic organic group may have a substituent. Examples of the substituent include an alkyl group (which may be either linear or branched, and preferably has 1 to 12 carbon atoms), a cycloalkyl group (which may be either monocyclic, polycyclic, or spirocyclic, and preferably has 3 to 20 carbon atoms), an aryl group (which preferably has 6 to 14 carbon atoms), a hydroxyl group, an alkoxy group, an ester group, an amide group, a urethane group, a ureido group, a thioether group, a sulfonamide group, and a sulfonate ester group. The carbon constituting the cyclic organic group (the carbon that contributes to ring formation) may be a carbonyl carbon.

[0298] The anion represented by formula (AN2) is 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 those in formula (AN2). q' represents an integer of 0 to 10.

[0299] W preferably contains a halogen atom. The halogen atom contained in W is preferably a fluorine atom or an iodine atom, and more preferably an iodine atom. When the resist composition is used as an EUV resist, the greater the number of halogen atoms, the better from the viewpoint of the absorption efficiency of EUV light. When an iodine atom is contained, a structure in which the iodine atom is directly bonded to a carbon atom on an aromatic ring is preferred.

[0300] As the anion represented by formula (AN2), the anions described in

[0076] of WO 2023 / 157455,

[0071] to

[0089] of JP-A 2021-81708,

[0033] to

[0045] of JP-A 2018-5224, and

[0031] to

[0039] of JP-A 2018-25789 are also preferred.

[0301] The non-nucleophilic anion is also preferably an aromatic sulfonate anion represented by the following formula (AN3).

[0302]

[0303] 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 the -(D-B) group. Examples of the substituent that may further be had include a fluorine atom and a hydroxyl group. n represents an integer of 0 or greater. n is preferably 1 to 4, more preferably 2 to 3, and even more preferably 3.

[0304] D represents a single bond or a divalent linking group. Examples of the divalent linking group include an ether group, a thioether group, a carbonyl group, a sulfoxide group, a sulfone group, a sulfonate ester group, an ester group, and a group formed by combining two or more of these groups.

[0305] B represents a hydrocarbon group. B is preferably an aliphatic hydrocarbon group, more preferably an isopropyl group, a cyclohexyl group, or an aryl group which may further have a substituent (such as a tricyclohexylphenyl group).

[0306] B preferably contains a halogen atom. The halogen atom contained in B is preferably a fluorine atom or an iodine atom, and more preferably an iodine atom. When the resist composition is used as an EUV resist, the greater the number of halogen atoms, the better, from the viewpoint of the absorption efficiency of EUV light. When an iodine atom is contained, a structure in which the iodine atom is directly bonded to a carbon atom on an aromatic ring is preferred.

[0307] As the anion represented by formula (AN3), the anions described in

[0029] to

[0034] of JP-A No. 2018-159744 and

[0045] of JP-A No. 2018-155908 are also preferred.

[0308] As the non-nucleophilic anion, a disulfonamide anion is also preferred. The disulfonamide anion is, for example, N － (SO ２ -R ｑ ) ２ where R ｑ represents an alkyl group which may have a substituent, preferably a fluoroalkyl group, more preferably a perfluoroalkyl group. ｑ may be bonded to each other to form a ring. ｑ The group formed by bonding together is preferably an alkylene group which may have a substituent, more preferably a fluoroalkylene group, and even more preferably a perfluoroalkylene group. The alkylene group preferably has 2 to 4 carbon atoms.

[0309] Further, examples of the non-nucleophilic anion include anions represented by the following formulas (d1-1) to (d1-4).

[0310]

[0311] In formula (d1-1), R ５１ represents a hydrocarbon group (for example, an aryl group such as a phenyl group) which may have a substituent (for example, a hydroxyl group).

[0312] In formula (d1-2), Z ２ｃ represents a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (provided that the carbon atom adjacent to S is not substituted with a fluorine atom). ２ｃThe hydrocarbon group in the formula (d1-2) may be linear or branched, or may have a cyclic structure. In addition, a carbon atom in the hydrocarbon group (preferably, a carbon atom that is a ring atom when the hydrocarbon group has a cyclic structure) may be a carbonyl carbon (-CO-). Examples of the hydrocarbon group include a group having a norbornyl group that may have a substituent. The carbon atom forming the norbornyl group may be a carbonyl carbon. ２ｃ -SO ３ － " is preferably different from the anions represented by the above formulae (AN1) to (AN3). For example, Z ２ｃ is preferably other than an aryl group. For example, Z ２ｃ In the -SO ３ － The atoms at the α-position and β-position to Z are preferably atoms other than carbon atoms having a fluorine atom as a substituent. ２ｃ is -SO ３ － The atom at the α-position and / or the atom at the β-position to the aryl group is preferably a ring atom in a cyclic group.

[0313] 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 a carbonyl group, and Rf represents a hydrocarbon group.

[0314] In formula (d1-4), R ５３ and R ５４ R each independently represents an organic group (preferably a hydrocarbon group having a fluorine atom). ５３ and R ５４ may be bonded to each other to form a ring.

[0315] The organic anions may be used alone or in combination of two or more.

[0316] The photoacid generator may be at least one selected from the group consisting of compounds (I) to (II). That is, it is also preferable that the resist composition further contains at least one of the following compounds (I) and (II).

[0317] (Compound (I)) Compound (I) is a compound having one or more structural moieties X and one or more structural moieties Y, which generates an acid containing the first acidic moiety derived from the structural moiety X and the second acidic moiety derived from the structural moiety Y when irradiated with actinic rays or radiation. Structural moiety X: Anionic moiety A １ － and the cationic moiety M １１ ＋ and by irradiation with actinic rays or radiation, HA １ Structural moiety Y: anionic moiety A, which forms a first acidic moiety represented by the formula: ２ － and the cationic moiety M １２ ＋ and by irradiation with actinic rays or radiation, HA ２ The compound (I) satisfies the following condition I:

[0318] Condition I: In the compound (I), the cationic moiety M in the structural moiety X １１ ＋ and the cationic moiety M in the structural moiety Y １２ ＋ H ＋ The compound PI in which the cation moiety M in the structural moiety X is replaced by １１ ＋ H ＋ HA is replaced by １ and the cationic moiety M in the structural moiety Y. １２ ＋ H ＋ HA is replaced by ２ and an acid dissociation constant a2 derived from the acidic site represented by the formula (I), and the acid dissociation constant a2 is greater than the acid dissociation constant a1.

[0319] Condition I will be explained in more detail below. For example, when compound (I) is an acid-generating compound having one of the first acidic sites derived from the structural moiety X and one of the second acidic sites derived from the structural moiety Y, compound PI is "HA １ and H.A. ２ The acid dissociation constant a1 and the acid dissociation constant a2 of the compound PI correspond to "a compound having the following structure." More specifically, when the acid dissociation constant of the compound PI is calculated, the acid dissociation constant a1 and the acid dissociation constant a2 of the compound PI correspond to "a compound having the following structure." １ － and H.A. ２ The pKa at which the compound becomes "a compound having the above formula (A)" is the acid dissociation constant a1, １ － and H.A. ２ "A compound having １ － and A ２ － The pKa at which the compound becomes "a compound having the above formula (I)" is the acid dissociation constant a2.

[0320] For example, when compound (I) is an acid-generating compound having two of the first acidic sites derived from the structural site X and one of the second acidic sites derived from the structural site Y, compound PI is a compound having two HAs. １ and one HA ２ When the acid dissociation constant of compound PI is calculated, compound PI corresponds to "a compound having one A １ － and one HA １ and one HA ２ and the acid dissociation constant when "a compound having one A １ － and one HA １ and one HA ２ "Compound having two A １ － and one HA ２ The acid dissociation constant when the compound is a compound having two A's corresponds to the acid dissociation constant a1. １ － and one HA ２ "Compound having two A １ － and A ２－ In other words, in the case of compound PI, the acid dissociation constant when the compound becomes a compound having the cation moiety M in the structural moiety X corresponds to the acid dissociation constant a2. １１ ＋ H ＋ HA is replaced by １ When the compound PI has a plurality of acid dissociation constants derived from the acidic moiety represented by the formula (I), the value of the acid dissociation constant a2 is larger than the largest value of the plurality of acid dissociation constants a1. １ － and one HA １ and one HA ２ The acid dissociation constant when the compound is aa is defined as "a compound having one A １ － and one HA １ and one HA ２ "Compound having two A １ － and one HA ２ When the acid dissociation constant when the compound becomes "a compound having the formula (I)" is ab, the relationship between aa and ab satisfies aa<ab.

[0321] The acid dissociation constants a1 and a2 are determined by the above-mentioned method for measuring an acid dissociation constant. The compound PI corresponds to the 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. In addition, when two or more of the above A １ － and two or more of the above M １１ ＋ In compound (I), the above A １ － and the above A ２ － , and the above M １１ ＋ and the above M １２ ＋ may be the same or different, but １ － and the above A ２ － are preferably different from each other.

[0322] 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, more preferably 0.5 or more, and even more preferably 1.0 or more. The upper limit of 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 not particularly limited, but is, for example, 16 or less.

[0323] In the compound PI, the acid dissociation constant a2 is preferably not more than 20, more preferably not more than 15. The lower limit of the acid dissociation constant a2 is preferably not less than −4.0.

[0324] In the compound PI, the acid dissociation constant a1 is preferably 2.0 or less, and more preferably 0 or less. The lower limit of the acid dissociation constant a1 is preferably −20.0 or more.

[0325] Anion site A １ － and anionic moiety A ２ － is a structural moiety containing a negatively charged atom or atomic group, and examples thereof include structural moieties selected from the group consisting of formulae (AA-1) to (AA-3) and formulae (BB-1) to (BB-6) shown below. １ － As the anionic moiety A, those capable of forming an acidic moiety with a small acid dissociation constant are preferred, and among these, any of formulas (AA-1) to (AA-3) is more preferred, and any of formulas (AA-1) and (AA-3) is even more preferred. ２ － As the anion moiety A １ － Preferably, it is one that can form an acidic site with a larger acid dissociation constant than the above, more preferably any of formulas (BB-1) to (BB-6), and even more preferably any of formulas (BB-1) and (BB-4). In the following formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6), * represents a bonding position. In formula (AA-2), R Ａ represents a monovalent organic group. ＡThe monovalent organic group represented by the formula (I) is not particularly limited, but examples thereof include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

[0326]

[0327]

[0328] Cationic moiety M １１ ＋ and cationic moiety M １２ ＋ is a structural moiety containing a positively charged atom or atomic group, and examples thereof include organic cations having a monovalent charge. ＋ Examples of the organic cation include those represented by the following formula:

[0329] (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, which generates an acid containing two or more of the first acidic moieties derived from the structural moiety X and the structural moiety Z upon irradiation with actinic rays or radiation. Structural moiety Z: a ​​nonionic moiety capable of neutralizing an acid

[0330] In compound (II), the definition of the structural moiety X and A １ － and M １１ ＋ The definition of the structural moiety X in compound (I) and A １ － and M １１ ＋ The definition and preferred embodiments are also the same.

[0331] In the compound (II), the cation moiety M in the structural moiety X １１ ＋ H ＋ In the compound PII, the cationic moiety M in the structural moiety X is replaced by １１ ＋ H ＋ HA is replaced by １The preferred range of the acid dissociation constant a1 derived from the acidic moiety represented by the formula (I) is the same as the acid dissociation constant a1 in the compound PI. In addition, when the compound (II) is, for example, a compound that generates an acid having two of the first acidic moieties derived from the structural moiety X and the structural moiety Z, the compound PII is a compound that generates an acid having two HAs. １ When the acid dissociation constant of this compound PII was calculated, it was found that the compound PII has "one A １ － and one HA １ and the acid dissociation constant when "a compound having one A １ － and one HA １ "Compound having two A １ － The acid dissociation constant when the compound becomes "a compound having the formula (I)" corresponds to the acid dissociation constant a1.

[0332] The acid dissociation constant a1 can be determined by the above-mentioned method for measuring an acid dissociation constant. The compound PII corresponds to the acid generated when compound (II) is irradiated with actinic rays or radiation. The two or more structural moieties X may be the same or different. １ － and two or more of the above M １１ ＋ may be the same or different.

[0333] The nonionic moiety capable of neutralizing an acid in the structural moiety Z is not particularly limited, and is preferably, for example, a moiety containing a group capable of electrostatically interacting with a proton or a functional group having electrons. Examples of the group capable of electrostatically interacting with a proton or the functional group having electrons include functional groups having a macrocyclic structure such as cyclic polyethers, and functional groups having a nitrogen atom with an unshared electron pair that does not contribute to π-conjugation. The nitrogen atom with an unshared electron pair that does not contribute to π-conjugation is, for example, a nitrogen atom having a partial structure shown in the following formula:

[0334]

[0335] Examples of the partial structure of a functional group having a group or electron capable of electrostatically interacting with a proton include a crown ether structure, an azacrown ether structure, a primary amine structure, a secondary amine structure, a tertiary amine structure, a pyridine structure, an imidazole structure, and a pyrazine structure. Of these, a primary amine structure, a secondary amine structure, a tertiary amine structure, and a tertiary amine structure are preferred.

[0336] Examples of moieties other than cations that Compound (I) and Compound (II) may have are shown below.

[0337]

[0338]

[0339] The photoacid generator may be an inner salt.

[0340] The content of the photoacid generator other than the salt compound (B) in the resist composition is not particularly limited, but the total content of the salt compound (B) and the photoacid generator other than the salt compound (B) is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 5.0% by mass or more, based on the total solid content of the resist composition. Furthermore, the total content of the salt compound (B) and the photoacid generator other than the salt compound (B) 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, based on the total solid content of the resist composition. Only one photoacid generator other than the salt compound (B) may be used, or two or more may be used. When two or more photoacid generators are used, the total content is preferably within the above-mentioned preferred content range.

[0341] <Acid Diffusion Controller> The resist composition preferably contains an acid diffusion controller. The acid diffusion controller can act as a quencher that traps acid generated from, for example, a photoacid generator during exposure and suppresses a reaction of the resin (A) in unexposed areas due to excess generated acid.

[0342] The type of acid diffusion controller is not particularly limited, and examples thereof include a basic compound (DA), a low-molecular-weight compound (DB) having a nitrogen atom and a group that is cleaved by the action of an acid, and a compound (DC) whose acid diffusion control ability is reduced or eliminated by irradiation with actinic rays or radiation. Examples of the compound (DC) include an onium salt compound (DD) of an acid that is relatively weaker than the acid generated from the photoacid generator, and a basic compound (DE) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation.

[0343] (Basic Compound (DA)) As the basic compound (DA), compounds having structures represented by the following formulae (A) to (E) are preferred.

[0344]

[0345] In formulas (A) and (E), R ２００ , R ２０１ and R ２０２ may be the same or different, and each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms), or an aryl group (preferably having 6 to 20 carbon atoms). ２００ , R ２０１ and R ２０２ At least two of R may be bonded to form a ring. ２０３ , R ２０４ , R ２０５ and R ２０６ may be the same or different, and each independently represents an alkyl group having 1 to 20 carbon atoms. In formulas (B), (C), (D), and (E), * represents a bonding position.

[0346] R in formulas (A) and (E) ２００ , R ２０１ , R ２０２ , R ２０３ , R ２０４ , R ２０５ and R ２０６The alkyl group or cycloalkyl group represented by may have a substituent or may be unsubstituted. With regard to the alkyl group, the alkyl group having a substituent is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms. R in formulas (A) and (E) ２００ , R ２０１ , R ２０２ , R ２０３ , R ２０４ , R ２０５ and R ２０６ The alkyl group or cycloalkyl group represented by is more preferably unsubstituted.

[0347] Examples of the basic compound (DA) include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine. The basic compound (DA) may be a compound having at least one structure selected from the group consisting of an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure, and a pyridine structure. The basic compound (DA) may be an alkylamine derivative having at least one structure selected from the group consisting of a hydroxyl group and an ether bond, or an aniline derivative having at least one structure selected from the group consisting of a hydroxyl group and an ether bond.

[0348] The difference between the pKa of the conjugate acid of the basic compound (DA) and the pKa of the acid generated from the photoacid generator (the value obtained by subtracting the pKa of the acid generated from the photoacid generator from the pKa of the conjugate acid of the basic compound (DA)) is preferably 1.00 or more, more preferably 1.00 to 14.00, and even more preferably 2.00 to 13.00. The pKa of the conjugate acid of the basic compound (DA) varies depending on the type of photoacid generator used, but is, for example, preferably 1.00 to 14.00, more preferably 3.00 to 13.00, and even more preferably 3.50 to 12.50.

[0349] (Onium Salt Compound (DD) of an Acid that is Relatively Weaker than the Acid Generated from a Photoacid Generator) The compound (DD) may be a compound that generates an acid upon irradiation with actinic rays or radiation. The compound (DD) is preferably a compound that generates an acid that has a pKa that is 1.00 or more higher than that of the acid generated from the photoacid generator. The difference between the pKa of the acid generated from the compound (DD) and the pKa of the acid generated from the photoacid generator (the value obtained by subtracting the pKa of the acid generated from the photoacid generator from the pKa of the acid generated from the compound (DD)) is preferably 1.00 or more, more preferably 1.00 to 10.00, even more preferably 1.00 to 5.00, and particularly preferably 1.00 to 3.00. The pKa of the acid generated from compound (DD) varies depending on the type of photoacid generator used, but is preferably, for example, 0.50 to 10.00, more preferably 0.80 to 5.00, and even more preferably 1.00 to 5.00.

[0350] Compound (DD) is preferably an onium salt compound consisting of an anion and a cation. Examples of compound (DD) include "M ＋ X － Examples of compounds include compounds (onium salts) represented by the formula "M ＋ represents a cation, and X － represents an anion. ＋ As the cation, an organic cation is preferred, and M ＋ The same as above can be mentioned. － is preferably an organic anion, and examples thereof include the anions represented by formulas (d1-1) to (d1-4) described in the description of the photoacid generator, and an anion represented by formula (d1-1) or an anion represented by formula (d1-2) is preferred.

[0351] Specific examples of the basic compound (DA) include those described in paragraphs

[0132] to

[0136] of WO 2020 / 066824, and specific examples of the basic compound (DE) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation include those described in paragraphs

[0137] to

[0155] of WO 2020 / 066824, and those described in paragraph

[0164] of WO 2020 / 066824, and specific examples of the low molecular weight compound (DB) having a nitrogen atom and having a group that leaves under the action of an acid include those described in paragraphs

[0156] to

[0163] of WO 2020 / 066824. Specific examples of the onium salt compound (DD) that is a weaker acid than the acid generated from a photoacid generator or the like include those described in paragraphs

[0305] to

[0314] of WO 2020 / 158337.

[0352] In addition to the above, for example, known compounds disclosed in paragraphs

[0627] to

[0664] of U.S. Patent Application Publication No. 2016 / 0070167A1, paragraphs

[0095] to

[0187] of U.S. Patent Application Publication No. 2015 / 0004544A1, paragraphs

[0403] to

[0423] of U.S. Patent Application Publication No. 2016 / 0237190A1, and paragraphs

[0259] to

[0328] of U.S. Patent Application Publication No. 2016 / 0274458A1 can be suitably used as the acid diffusion controller.

[0353] Among the acid diffusion controllers, the compound (DC) is also referred to as a photodegradable base. It is also preferable that the resist composition further contains a photodegradable base.

[0354] The molecular weight of the acid diffusion controller is not particularly limited, but is preferably 100 to 3,000, more preferably 150 to 2,500, and even more preferably 200 to 2,000.

[0355] The acid diffusion controller is also preferably a compound that generates an acid having a pKa of 0 or more upon irradiation with actinic rays or radiation.

[0356] The acid diffusion controller may be an inner salt.

[0357] The content of the acid diffusion controller in the resist composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, based on the total solid content of the resist composition. Furthermore, the content of the acid diffusion controller is preferably 50.0% by mass or less, more preferably 40.0% by mass or less, and even more preferably 30.0% by mass or less, based on the total solid content of the resist composition. Only one acid diffusion controller may be used, or two or more may be used. When two or more types are used, the total content thereof is preferably within the above-mentioned preferred content range.

[0358] <Hydrophobic Resin> The resist composition may further contain a hydrophobic resin different from the resin (A). The hydrophobic resin is preferably designed so that it is unevenly distributed on the surface of the resist film, but unlike surfactants, it does not necessarily have to have a hydrophilic group in its molecule, and it does not necessarily have to contribute to uniform mixing of the polar substance and the non-polar substance.

[0359] The hydrophobic resin contains fluorine atoms, silicon atoms, and CH atoms contained in the side chain portion of the resin in order to be unevenly distributed on the surface layer of the film. ３ It is preferable to have one or more of the partial structures, and more preferably two or more. The hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted on a side chain. Examples of hydrophobic resins include the compounds described in paragraphs

[0275] to

[0279] of WO 2020 / 004306.

[0360] When the resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01 to 20.0 mass%, and more preferably 0.1 to 15.0 mass%, based on the total solids content of the resist composition. Only one type of hydrophobic resin may be used, or two or more types may be used. When two or more types are used, the total content thereof preferably falls within the above-mentioned preferred content range.

[0361] <Surfactant> The resist composition may contain a surfactant. When the resist composition contains a surfactant, it is possible to form a pattern with better adhesion and fewer development defects. The surfactant is preferably a fluorine-based and / or silicon-based surfactant. Examples of the fluorine-based and / or silicon-based surfactant include the surfactants disclosed in paragraphs

[0218] and

[0219] of WO 2018 / 193954.

[0362] When the resist composition contains a surfactant, the content of the surfactant is preferably 0.0001 to 2.0 mass%, more preferably 0.0005 to 1.0 mass%, and even more preferably 0.1 to 1.0 mass%, relative to the total solids content of the resist composition. One type of surfactant may be used, or two or more types may be used. When two or more types are used, it is preferable that the total content thereof is within the above-mentioned preferred content range.

[0363] <Solvent> The resist composition contains a solvent. The solvent preferably contains (M1) propylene glycol monoalkyl ether carboxylate and (M2) at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate ester, acetate ester, alkoxypropionate ester, chain ketone, cyclic ketone, lactone, and alkylene carbonate. The solvent may further contain components other than components (M1) and (M2).

[0364] Combining the above-mentioned solvent with the above-mentioned resin is preferable in terms of improving the coatability of the resist composition and reducing the number of development defects in the pattern. The above-mentioned solvent has a good balance of the solubility, boiling point, and viscosity of the above-mentioned resin, so it is possible to suppress unevenness in the film thickness of the resist film and the occurrence of precipitates during spin coating. Details of component (M1) and component (M2) are described in paragraphs

[0218] to

[0226] of WO 2020 / 004306, the contents of which are incorporated herein by reference.

[0365] When the solvent further contains components other than the components (M1) and (M2), the content of the components other than the components (M1) and (M2) is preferably 5 to 30 mass % based on the total amount of the solvent.

[0366] The content of the solvent in the resist composition is preferably determined so that the solids concentration is from 0.5 to 30 mass %, and more preferably from 1 to 20 mass %, which further improves the coatability of the resist composition.

[0367] <Other Additives> The resist composition may further contain at least one selected from the group consisting of a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and a compound that promotes solubility in a developer (for example, a phenol compound having a molecular weight of 1000 or less, or an alicyclic or aliphatic compound containing a carboxyl group). The "dissolution inhibiting compound" is a compound having a molecular weight of 3000 or less that decomposes under the action of an acid and thereby reduces its solubility in an organic developer.

[0368] The content of the other additives is not particularly limited, but may be 20.0% by mass or less, 10.0% by mass or less, or 5.0% by mass or less, based on the total solid content of the resist composition. Only one type of other additive may be used, or two or more types may be used. When two or more types are used, it is preferable that the total content thereof is within the above-mentioned preferred content range.

[0369] The resist composition may also contain water as an impurity. When water is contained as an impurity, the lower the content of water, the more preferable, but the resist composition may contain 1 to 30,000 ppm by mass of water relative to the total solid content of the resist composition. The resist composition may also contain residual monomers as impurities (for example, monomers derived from the raw material monomers used in the synthesis of the resin (A)). When water is contained as an impurity, the lower the content of residual monomers, the more preferable, but the resist composition may contain 1 to 30,000 ppm by mass of water relative to the total solid content of the resist composition.

[0370] [Resist Film and Pattern Forming Method] The present invention also relates to a resist film formed from the above-mentioned actinic ray-sensitive or radiation-sensitive resin composition. The present invention also relates to a pattern forming method comprising the steps of forming a resist film on a substrate using the above-mentioned actinic ray-sensitive or radiation-sensitive resin composition, exposing the resist film to light, and developing the exposed resist film using a developer.

[0371] The procedure for the pattern formation method using the resist composition is not particularly limited, but preferably includes the following steps: Step 1: Forming a resist film on a substrate using the resist composition, Step 2: Exposing the resist film to light, and Step 3: Developing the exposed resist film using a developer. The procedure for each of the above steps will now be described in detail.

[0372] <Step 1: Resist Film Forming Step> Step 1 is a step of forming a resist film on a substrate using a resist composition. The definition of the resist composition is as described above.

[0373] A method for forming a resist film on a substrate using a resist composition includes, for example, applying the resist composition to the substrate. It is preferable to filter the resist composition 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. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

[0374] The resist composition can be applied onto a substrate (e.g., silicon, silicon dioxide coated) such as those used in the manufacture of integrated circuit elements by an appropriate application method such as a spinner or coater. Spin application using a spinner is preferred. The rotation speed when spin application using a spinner is preferably 1000 to 3000 rpm. After application of the resist composition, the substrate may be dried to form a resist film. If necessary, various undercoating films (inorganic film, organic film, anti-reflective film) may be formed below the resist film.

[0375] An example of a drying method is a method of drying by heating. Heating can be performed by means provided in a normal exposure machine and / or developing machine, and may also be performed using a hot plate or the like. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is preferably 30 to 1,000 seconds, more preferably 60 to 800 seconds, and even more preferably 60 to 600 seconds.

[0376] The thickness of the resist film is not particularly limited, but is preferably 10 to 120 nm from the viewpoint of forming a finer pattern with higher precision. In particular, when EUV exposure and EB exposure are used, the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. Furthermore, when ArF immersion exposure is used, the thickness of the resist film is more preferably 10 to 120 nm, and even more preferably 15 to 90 nm.

[0377] A top coat may be formed on the resist film using a top coat composition. It is preferable that the top coat composition does not mix with the resist film and can be uniformly applied to the resist film. The top coat is not particularly limited, and a conventionally known top coat can be formed by a conventionally known method. For example, a top coat can be formed based on the description in paragraphs

[0072] to

[0082] of JP 2014-059543 A. For example, a top coat containing a basic compound such as that described in JP 2013-061648 A is preferably formed on the resist film. Specific examples of basic compounds that may be contained in the top coat include basic compounds that may be contained in the resist composition. It is also preferable that the top coat contain 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.

[0378] <Step 2: Exposure Step> Step 2 is a step of exposing the resist film. Examples of exposure methods include irradiating the formed resist film with actinic rays or radiation through a predetermined mask. Examples of actinic rays or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams, and preferably far ultraviolet light with a wavelength of 250 nm or less, more preferably 220 nm or less, and particularly preferably 1 to 200 nm, specifically KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ２ These include excimer laser (157 nm), EUV (13 nm), X-ray, and electron beam.

[0379] After exposure, it is preferable to perform post-exposure heat treatment (also referred to as post-exposure baking) before development. Post-exposure heat treatment promotes the reaction of 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, and even more preferably 80 to 130°C. The heating time is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. Heating can be performed using means provided in a typical exposure machine and / or development machine, and may also be performed using a hot plate or the like.

[0380] <Step 3: Development Step> Step 3 is a step of developing the exposed resist 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).

[0381] Examples of development methods include a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which a developer is piled up on the surface of a substrate by surface tension and then left stationary for a certain period of time for development (puddle method), a method in which a developer is sprayed onto the surface of the substrate (spray method), and a method in which a developer is continuously dispensed onto a substrate rotating at a constant speed while a developer dispense nozzle is scanned at a constant speed (dynamic dispense method). After the development step, a step of stopping development while replacing the solvent with another solvent may be carried out. The development time is not particularly limited as long as it is long enough to sufficiently dissolve the resin in the unexposed areas, 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.

[0382] The alkaline developer is preferably an aqueous alkaline solution containing an alkali. The type of alkaline aqueous solution is not particularly limited, but examples include aqueous alkaline solutions containing a quaternary ammonium salt, such as tetramethylammonium hydroxide, an inorganic alkali, a primary amine, a secondary amine, a tertiary amine, an alcohol amine, or a cyclic amine. Of these, the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt, such as tetramethylammonium hydroxide (TMAH). Appropriate amounts of alcohols, surfactants, and the like may be added to the alkaline developer. The alkaline concentration of the alkaline developer is usually preferably 0.1 to 20% by mass. The pH of the alkaline developer is usually preferably 10.0 to 15.0.

[0383] The organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents.

[0384] The above-mentioned solvents may be mixed in plural, 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, even more preferably 90% by mass or more and 100% by mass or less, and particularly preferably 95% by mass or more and 100% by mass or less, based on the total amount of the developer.

[0385] Preferred embodiments of the organic developer include the following embodiments (OD1) and (OD2). (OD1) An embodiment in which the organic developer is n-butyl acetate. (OD2) An embodiment in which the organic developer is a mixed solvent of n-butyl acetate and a hydrocarbon having 11 or more carbon atoms. The mixed solvent of (OD2) above is also referred to as mixed solvent (OD2). The hydrocarbon having 11 or more carbon atoms in mixed solvent (OD2) is preferably an alkane, more preferably an alkane having 11 to 15 carbon atoms, even more preferably an alkane having 11 to 13 carbon atoms, particularly preferably undecane or dodecane, and most preferably undecane. Note that when structural isomers exist, such as undecane and dodecane, the hydrocarbon having 11 or more carbon atoms may contain the structural isomer. The hydrocarbon having 11 or more carbon atoms contained in mixed solvent (OD2) may be one type or two or more types. The content of hydrocarbons having 11 or more carbon atoms in the mixed solvent (OD2) (the total amount when multiple hydrocarbons having 11 or more carbon atoms are contained) is preferably 1% by mass or more and 35% by mass or less, more preferably 5% by mass or more and 30% by mass or less, and even more preferably 10% by mass or more and 25% by mass or less, based on 100% by mass of the entire mixed solvent (OD2).

[0386] The content of n-butyl acetate in the mixed solvent (OD2) is preferably 65% ​​by mass or more and 99% by mass or less, more preferably 70% by mass or more and 95% by mass or less, and even more preferably 75% by mass or more and 90% by mass or less, with the entire mixed solvent (OD2) being 100% by mass.

[0387] A particularly preferred embodiment of the mixed solvent (OD2) is one containing n-butyl acetate and undecane, with the mass ratio of "n-butyl acetate / undecane" being "90 / 10".

[0388] The developer may contain other components in addition to the components described above. Examples of other components include surfactants, antioxidants, basic compounds, etc. The content of other components in the developer is preferably 0% by mass or more and 5% by mass or less, more preferably 0% by mass or more and 1% by mass or less, even more preferably 0% by mass or more and 0.5% by mass or less, based on 100% by mass of the entire developer, and particularly preferably 0% by mass (i.e., no other components are contained).

[0389] <Other Steps> The pattern formation method preferably includes, after step 3, a step of cleaning with a rinse liquid.

[0390] The rinse liquid used in the rinse step after the development step using an alkaline developer can be, for example, pure water. A suitable amount of surfactant may be added to the pure water. A suitable amount of surfactant may be added to the rinse liquid.

[0391] The rinse liquid used in the rinse step after the development step using an organic developer is not particularly limited as long as it does not dissolve the pattern, and a solution containing a general organic solvent can be used. The rinse liquid is preferably a rinse liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

[0392] The method for the rinsing step is not particularly limited, and examples include a method in which a rinsing solution is continuously discharged onto a substrate rotating at a constant speed (spin coating method), a method in which a substrate is immersed in a tank filled with the rinsing solution for a certain period of time (dipping method), and a method in which the rinsing solution is sprayed onto the surface of the substrate (spray method). The pattern formation method of the present invention may also include a heating step (post-bake) after the rinsing step. This step removes the developer and rinsing solution remaining between and within the pattern by baking. This step also has the effect of annealing the resist pattern and improving the surface roughness of the pattern. The heating step after the rinsing step is typically performed at 40 to 250°C (preferably 90 to 200°C) for typically 10 seconds to 3 minutes (preferably 30 to 120 seconds).

[0393] Alternatively, the substrate may be etched using the formed pattern as a mask. That is, the substrate (or the underlayer film and the substrate) may be processed using the pattern formed in step 3 as a mask to form a pattern on the substrate. The method for processing the substrate (or the underlayer film and the substrate) is not particularly limited, but a method of forming a pattern on the substrate by dry etching the substrate (or the underlayer film and the substrate) using the pattern formed in step 3 as a mask is preferred. The dry etching is preferably oxygen plasma etching.

[0394] The resist composition and various materials used in the pattern formation method of the present invention (e.g., solvent, developer, rinse, anti-reflective coating composition, top coat composition, etc.) preferably do not contain impurities such as metals. The content of impurities contained in these materials is preferably 1 mass ppm or less, more preferably 10 mass ppb or less, even more preferably 100 mass ppt or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. Here, examples of metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn.

[0395] Examples of methods for removing impurities such as metals from various materials include filtration using a filter. Details of filtration using a filter are described in paragraph

[0321] of WO 2020 / 004306.

[0396] Methods for reducing impurities such as metals contained in various materials include, for example, selecting raw materials with a low metal content as raw materials for the various materials, filtering the raw materials for the various materials, and performing distillation under conditions that minimize contamination as much as possible, for example by lining the inside of the apparatus with Teflon (registered trademark).

[0397] In addition to filter filtration, impurities may be removed using an adsorbent, or a combination of filter filtration and an adsorbent may be used. Known adsorbents can be used as the adsorbent, including inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon. In order to reduce impurities such as metals contained in the various materials, it is necessary to prevent the incorporation of metal impurities during the manufacturing process. Whether metal impurities have been sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of metal components contained in the cleaning solution used to clean the manufacturing equipment. The content of metal components contained in the used cleaning solution is preferably 100 parts per trillion (ppt) by mass or less, more preferably 10 ppt by mass or less, and even more preferably 1 ppt by mass or less.

[0398] The resist composition may also contain water as an impurity. When water is contained as an impurity, the lower the content of water, the more preferable, but the resist composition may contain 1 to 30,000 ppm by mass of water relative to the entire resist composition. The resist composition may also contain residual monomers as impurities (for example, monomers derived from the raw material monomers used in the synthesis of resin (X)). When residual monomers are contained as impurities, the lower the content of residual monomers, the more preferable, but the resist composition may contain 1 to 30,000 ppm by mass of water relative to the entire solid content of the resist composition.

[0399] A conductive compound may be added to an organic processing liquid such as a rinse solution to prevent breakdown of the chemical solution piping and various parts (filters, O-rings, tubes, etc.) due to static charging and subsequent electrostatic discharge. The conductive compound is not particularly limited, but examples include methanol. The amount added is not particularly limited, but in order to maintain favorable development or rinsing characteristics, it is preferably 10% by mass or less, and more preferably 5% by mass or less. For the chemical solution piping, for example, stainless steel (SUS), or various piping coated with antistatically treated polyethylene, polypropylene, or fluororesin (such as polytetrafluoroethylene or perfluoroalkoxy resin), can be used. Similarly, for the filters and O-rings, polyethylene, polypropylene, or fluororesin (such as polytetrafluoroethylene or perfluoroalkoxy resin) that have been antistatically treated can be used.

[0400] [Method for Manufacturing an Electronic Device] The present specification also relates to a method for manufacturing an electronic device, including the above-mentioned pattern formation method, and an electronic device manufactured by this manufacturing method. Preferred embodiments of the electronic device of the present specification include those installed in electrical and electronic devices (such as home appliances, office automation (OA), media-related devices, optical devices, and communication devices).

[0401] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

[0402] The various components used in the resist compositions of the examples and comparative examples are shown below.

[0403] <Resin> P-1 to P-20 were used as resin (A). The structures of P-1 to P-20 are shown below. The content ratio of the following repeating units (content relative to all repeating units in the resin) is a molar ratio. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the resin were measured by GPC (carrier: tetrahydrofuran (THF)) (amounts converted into polystyrene). The content of the repeating units was １３ Measurement was performed by C-NMR (nuclear magnetic resonance).

[0404]

[0405]

[0406]

[0407] <Salt Compound (B)> B-1 to B-27 were used as salt compounds (B). H-1 to H-3 were used as comparative compounds. Me represents a methyl group.

[0408]

[0409]

[0410]

[0411]

[0412]

[0413]

[0414]

[0415] (Decomposition rate of acid-decomposable groups) As described above, in this specification, the term "Lewis acid capable of decomposing acid-decomposable groups" refers to a Lewis acid that decomposes 20% or more of the acid-decomposable groups (groups in which carboxy groups are protected with cyclopentylmethyl groups) in compound (Q) when compound (Q) below is dissolved in toluene to a concentration of 0.33 M, 0.1 eq of a Lewis acid compound is added to the solution, and the mixture is heated at 90°C for 90 minutes (i.e., the cyclopentylmethyl groups, which are protecting groups, are deprotected to produce methacrylic acid). The decomposition rate of the acid-decomposable groups in compound (Q) was measured using deuterated DMSO (deuterated dimethyl sulfoxide) as a deuterated solvent. １ This can be done by H-NMR (nuclear magnetic resonance) measurement.

[0416]

[0417] The Lewis acid compound refers to a Lewis acid compound generated by irradiating a salt compound that generates a Lewis acid when irradiated with actinic rays or radiation. For the above compounds B-1 to B-27 and H-1 to H-3, Lewis acids were obtained by purchasing commercially available products or by the synthesis described below. These were used as Lewis acid compounds. <Synthesis> 1 g of a salt compound that generates a Lewis acid was dissolved in 10 ml of toluene, to which 1 g of trifluoromethanesulfonic acid was added, followed by stirring at 80°C for 6 hours. The reaction solution was quenched with 10 ml of saturated aqueous sodium bicarbonate, and after separation, the toluene layer was concentrated. The resulting mixture was purified by column chromatography to obtain the desired Lewis acid compound.

[0418] The decomposition rates of the Lewis acids generated from B-1 to B-27 were all 20% or higher, whereas the Lewis acids generated from H-1 to H-3 were either not generated or were less than 20%.

[0419] Furthermore, for the salt compounds (B-1 to B-27), the amount of Lewis acid generated relative to the amount of salt compound calculated by the following procedure was calculated.

[0420] 1. A salt compound is added at 0.3 mmol / g to parahydroxystyrene (PHS) homopolymer (VP-2500 (manufactured by Nippon Soda Co., Ltd.)) and dissolved in a solvent (propylene glycol monomethyl ether (PGME) / propylene glycol monomethyl ether acetate (PGMEA) = 1.1 (mass ratio)) to prepare a solution with a solids concentration of 3 mass %. The solids refer to components other than the solvent. 2. This solution is applied to a silicon wafer and dried by heating at 90°C to form a resist film with a thickness of 60 nm. 3. EB exposure (2000 kGy) is performed on the entire surface. 4. A 10 cm 2 portion of the exposed film is ２ The resulting solution is extracted with DMSO (2 ml) and subjected to HPLC analysis. The amount of Lewis acid generated is determined by comparing the unexposed sample with the 2000 kGy exposed sample. 5. The amount of Lewis acid generated relative to the amount of salt compound added is calculated.

[0421] The HPLC measurement conditions are as follows: 1 mL of DMSO was added to 1 mg of substrate samples coated with a resist film (for each of "unexposed sample" and "2000 kGy exposed sample") (1.3 cm x 0.8 cm x 9 sheets) or a standard sample, and ultrasonic waves were applied at 25°C for 15 minutes. After thorough mixing, HPLC measurement was performed under the following conditions: Apparatus: Prominence (Shimadzu Corporation), Column: Mightysil RP-18 (4.6 mmφ x 250 mm), Solution A: acetonitrile, Solution B: water (0.1 vol% acetic acid + 0.1 vol% triethylamine), Flow rate: 1.0 mL / min, A conc. : 5% (0 min) → 100% (28 min) → 100% (40 min) → 5% (40.1 min) → 5% (50 min), Column oven: 40°C, Detector: PDA, Injection volume: 10 μL

[0422] Lewis acid generation amount (mol %)=(1−(area of ​​salt compound in exposed film / area of ​​salt compound in unexposed film)×100

[0423] In B-1 to B-27, the amount of Lewis acid generated relative to the amount of salt compound was 30 mol % or more in all cases.

[0424] <Photoacid Generators Other Than Salt Compound (B)> S-1 to S-12 were used as photoacid generators other than salt compound (B), where Me represents a methyl group.

[0425]

[0426]

[0427] <Acid Diffusion Controller> Q-1 to Q-7 were used as the acid diffusion controller, all of which are photodegradable bases.

[0428]

[0429] <Solvents> The solvents used are as follows: D-1: Propylene glycol monomethyl ether acetate (PGMEA) D-2: Propylene glycol monomethyl ether (PGME) D-3: Cyclohexanone D-4: Ethyl lactate D-5: γ-butyrolactone D-6: Diacetone alcohol

[0430] <Preparation of Resist Compositions> The components shown in Tables 1 and 2 below were dissolved in the solvents shown in the tables to prepare solutions, and these were then filtered through a polyethylene filter with a pore size of 0.02 μm to prepare resist compositions (Re-1 to Re-57, and Hre-1 to Hre-3). In the tables, the column titled "Content" indicates the content (mass %) of each component relative to the total solids content in the resist composition. The solids content refers to components other than the solvent. Furthermore, in the tables, the column titled "Content (relative to total amount of resin)" indicates the content (mass %) of each resin relative to the total amount of resin. The mixing ratio of the solvents refers to the proportion (mass ratio) of each solvent when the total amount of solvent is taken as 100.

[0431]

[0432]

[0433] [Pattern Formation and Evaluation] <Pattern Formation Method (1): EUV Exposure, Alkali Development (Positive)> An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a film with a thickness of 5 nm. Each resist composition shown in Tables 3 and 4 was applied thereon and baked (PB) at 90°C for 60 seconds to form a resist film with a thickness of 45 nm. The wafer on which the resist film obtained above was formed was subjected to pattern irradiation with the same uniform exposure dose over the entire wafer surface using an EUV exposure device (Micro Exposure Tool manufactured by Exitech, NA (numerical aperture) 0.3, Quadruple, outer sigma 0.68, inner sigma 0.36) as an exposure source and an exposure mask (line / space = 1 / 1). After the exposure, the resist was baked (PEB) on a hot plate at 90° C. for 60 seconds, then developed with an aqueous solution of tetramethylammonium hydroxide (2.38% by mass) for 30 seconds, and spin-dried to obtain a positive pattern.

[0434] [Evaluation] The obtained patterns were evaluated for resolution and LWR performance by the following methods. The results are shown in Tables 3 and 4.

[0435] The irradiation energy required to resolve a 1:1 line and space pattern with a line width of 50 nm was taken as the sensitivity (Eop).

[0436] <L / S Resolution> The limiting resolving power (the minimum line width at which a line and a space (line:space = 1:1) are separately resolved) at the exposure dose that indicates the above sensitivity (Eop) was defined as the resolving power (nm). A smaller value indicating the resolution indicates that a finer pattern can be resolved, and indicates a higher resolving power. More specifically, the resolution is preferably 15 nm or less, more preferably 14 nm or less, and even more preferably 13 nm or less.

[0437] <Evaluation of LWR> At an exposure dose such that the line width of a line and space pattern with a line:space = 1:1 ratio was 20 nm, the pattern was observed from above using a critical dimension scanning electron microscope (SEM (Hitachi, Ltd. S-9380II)), and 100 line widths in each line pattern were measured. The LWR (nm) was evaluated by determining three times the standard deviation (σ) of the average value calculated from the measurement results (3σ). The LWR (3σ) values ​​are shown in Table 5. The smaller the 3σ value, the better the LWR performance. The LWR (nm) expressed as 3σ is preferably 4.2 nm or less, more preferably 3.8 nm or less, and even more preferably 3.5 nm or less.

[0438]

[0439]

[0440] <Pattern Forming Method (2): EUV Exposure, Organic Solvent Development (Negative)> An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a film with a thickness of 5 nm. Each resist composition shown in Tables 5 and 6 was applied thereon and baked (PB) at 90°C for 60 seconds to form a resist film with a thickness of 45 nm. The wafer on which the resist film was formed was subjected to pattern irradiation with a uniform exposure dose over the entire wafer surface using an EUV exposure device (Micro Exposure Tool manufactured by Exitech, NA (numerical aperture) 0.3, Quadruple, outer sigma 0.68, inner sigma 0.36) as an exposure source and an exposure mask (line / space = 1 / 1). After exposure, the wafer was baked (PEB) at 90°C for 60 seconds on a hot plate. Thereafter, the resist was developed with butyl acetate for 30 seconds and then spin-dried to obtain a negative pattern.

[0441] [Evaluation] The obtained patterns were evaluated for resolution and LWR performance in the same manner as above. The results are shown in Tables 5 and 6.

[0442]

[0443]

[0444] <Pattern formation method (3): ArF exposure, alkali development (positive)> The same steps as in the pattern formation method (1) were performed, except that each resist composition shown in Tables 7 and 8 was used, and an ArF excimer laser scanner (manufactured by ASML, PAS5500 / 1500, wavelength 193 nm, NA 0.50) was used instead of the EUV exposure device.

[0445] [Evaluation] The obtained patterns were evaluated for resolution and LWR performance by the following methods. The results are shown in Tables 7 and 8.

[0446] The irradiation energy required to resolve a 1:1 line and space pattern with a line width of 80 nm was taken as sensitivity (Eop).

[0447] <L / S Resolution> The limiting resolving power (the minimum line width at which a line and a space (line:space = 1:1) are separately resolved) at the exposure dose that indicates the above sensitivity (Eop) was defined as the resolving power (nm). A smaller value indicating the resolution indicates that a finer pattern can be resolved, and indicates a higher resolving power. More specifically, the resolution is preferably 60 nm or less, more preferably 58 nm or less, and even more preferably 56 nm or less.

[0448] <Evaluation of LWR> At an exposure dose such that the line width of a line and space pattern with a line:space = 1:1 ratio was 80 nm, the pattern was observed from above using a critical dimension scanning electron microscope (SEM (Hitachi, Ltd. S-9380II)), and 100 line widths in each line pattern were measured. The LWR (nm) was evaluated by determining three times the standard deviation (σ) of the average value calculated from the measurement results (3σ). The LWR (3σ) values ​​are shown in Table 5. The smaller the 3σ value, the better the LWR performance. The LWR (nm) expressed by 3σ is preferably 6.2 nm or less, more preferably 5.8 nm or less, and even more preferably 5.6 nm or less.

[0449]

[0450]

[0451] <Pattern formation method (4): ArF exposure, organic solvent development (negative)> The same steps as in the pattern formation method (2) were performed, except that each resist composition shown in Tables 9 and 10 was used, and an ArF excimer laser scanner (manufactured by ASML, PAS5500 / 1500, wavelength 193 nm, NA 0.50) was used instead of the EUV exposure device.

[0452] [Evaluation] The obtained patterns were evaluated for resolution and LWR in the same manner as in the evaluation of the pattern formation method (3). The results are shown in Tables 9 and 10.

[0453]

[0454]

[0455] From the above results, it was found that the resist compositions used in the examples were excellent in resolution and LWR performance.

[0456] The present invention provides an actinic ray-sensitive or radiation-sensitive resin composition capable of forming a pattern excellent in resolution and LWR. The present invention also provides a resist film, a pattern forming method, and a method for manufacturing an electronic device, which use the actinic ray-sensitive or radiation-sensitive resin composition.

[0457] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2024-089325) filed on May 31, 2024, the contents of which are incorporated herein by reference.

Claims

1. An actinic ray- or radiation-sensitive resin composition comprising: (A) a resin having an acid-decomposable group; and (B) a salt compound that generates a Lewis acid capable of decomposing the acid-decomposable group upon irradiation with actinic rays or radiation.

2. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, wherein the salt compound (B) is a salt compound that generates the Lewis acid upon decomposition of an anion in the salt compound (B) upon irradiation with actinic rays or radiation.

3. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the salt compound (B) has at least one iodine atom on the anion.

4. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the salt compound (B) has an anion containing a Group 13 element or a Group 14 element.

5. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the salt compound (B) has an anion containing boron or silicon.

6. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the salt compound (B) is an onium salt compound represented by any one of the following general formulas (BI) to (BIII): In general formulas (BI) to (BIII), R １ ~R ３ R each independently represents an aromatic ring group. ４ ~R １０ R each independently represents an aromatic ring group. １ ~R ３ At least two of R ４ ~R ６ and at least two of R ７ ~R １０ At least two of X may be bonded to each other to form a ring structure. １ ~X ３ Each of Y independently represents a monovalent organic group. １ ＋ ~Y ３ ＋ each independently represents a cation.

7. R in the general formula (BI) １ ~R ３ The actinic ray-sensitive or radiation-sensitive resin composition according to claim 6 , wherein at least one of the following has an electron-withdrawing group.

8. Y in the general formulae (BI) to (BIII) １ ＋ ~Y ３ ＋ The actinic ray-sensitive or radiation-sensitive resin composition according to claim 6, wherein is a cation that decomposes upon irradiation with actinic rays or radiation.

9. Y in the general formulae (BI) to (BIII) １ ＋ ~Y ３ ＋ The actinic ray-sensitive or radiation-sensitive resin composition according to claim 6 , wherein is a sulfonium cation or an iodonium cation.

10. Y in the general formulae (BI) to (BIII) １ ＋ ~Y ３ ＋ 7. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 6, wherein is a triarylsulfonium cation or a diaryliodonium cation.

11. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, further comprising a compound other than the salt compound (B) that generates an acid upon irradiation with actinic rays or radiation.

12. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, further comprising a photodegradable base.

13. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, further comprising at least one of the following compounds (I) and (II): Compound (I): A compound having one or more structural moieties X and one or more structural moieties Y, which generates an acid containing the following first acidic moiety derived from the structural moiety X and the following second acidic moiety derived from the structural moiety Y upon irradiation with actinic rays or radiation. Structural moiety X: Anionic moiety A １ － and the cationic moiety M １１ ＋ and HA is produced by irradiation with actinic rays or radiation. １ Structural moiety Y: anionic moiety A, which forms a first acidic moiety represented by the formula: ２ － and the cationic moiety M １２ ＋ and HA is produced by irradiation with actinic rays or radiation. ２ However, compound (I) satisfies the following condition I. Condition I: In compound (I), the cationic moiety M in the structural moiety X is １１ ＋ and the cationic moiety M in the structural moiety Y １２ ＋ H ＋ The compound PI in which the cationic moiety M in the structural moiety X is replaced by １１ ＋ H ＋ HA is replaced by １ and the cationic moiety M in the structural moiety Y. １２ ＋ H ＋ HA is replaced by ２ and the acid dissociation constant a2 is greater than the acid dissociation constant a1. Compound (II): A compound having two or more of the structural moieties X and one or more of the following structural moieties Z, which generates an acid upon irradiation with actinic rays or radiation, the compound including two or more of the first acidic moieties derived from the structural moiety X and the structural moiety Z. Structural moiety Z: a ​​non-ionic moiety capable of neutralizing an acid 14. A resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2.

15. A pattern forming method comprising the steps of: forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2; exposing the resist film; and developing the exposed resist film using a developer.

16. A method for manufacturing an electronic device, comprising the pattern formation method according to claim 15.

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