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

Abstract

A first problem to be addressed by the present invention is to provide an actinic ray-sensitive or radiation-sensitive resin composition having little dependence on heating temperature after exposure and before development. A second problem to be addressed by the present invention is to provide a resist film, a pattern formation method, and an electronic device production method, which relate to the actinic ray-sensitive or radiation-sensitive resin composition.　An actinic ray-sensitive or radiation-sensitive resin composition according to the present invention contains a resin, a photo-acid-generating agent, and an acid diffusion control agent, wherein at least one of the photo-acid-generating agent and the acid diffusion control agent is a compound represented by formula (1).

Description

Photosensitive or radiation-sensitive resin composition, resist film, pattern forming method, method for manufacturing electronic devices

[0001] The present invention relates to a photosensitive or radiation-sensitive resin composition, a resist film, a pattern forming method, and a method for manufacturing an electronic device.

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

[0003] Furthermore, in addition to excimer laser light, lithography using electron beams (EB), X-rays, and extreme ultraviolet (EUV) light is currently under development. Accordingly, resist compositions that are effectively sensitive to various types of active light or radiation are being developed.

[0004] For example, Patent Document 1 discloses a resist composition containing the following photoacid generator I2.

[0005]

[0006] Japanese Patent Publication No. 2012-121879

[0007] Incidentally, when forming a pattern by exposing and developing a resist film, it is common practice to perform a post-exposure bake (PEB) on the exposed resist film before developing. The inventors investigated the resist composition described in Patent Document 1 and found that the LWR (Line Width Roughness) performance may vary depending on the heating temperature of the post-exposure bake (PEB) during pattern formation. In other words, they found that improvements are needed to reduce the dependence of the resist composition on the heating temperature during post-exposure bake (PEB).

[0008] Therefore, the object of the present invention is to provide a photosensitive or radiation-sensitive resin composition that exhibits little dependence on heating temperature in post-exposure heating (PEB). Furthermore, the object of the present invention is to provide a resist film, a pattern formation method, and a method for manufacturing an electronic device relating to the above-mentioned photosensitive or radiation-sensitive resin composition.

[0009] As a result of diligent research to solve the above problems, the inventors have found that the above problems can be solved by the following configuration.

[0010] [1] A photosensitive or radiation-sensitive resin composition comprising a resin, a photoacid generator, and an acid diffusion control agent, wherein at least one of the photoacid generator and the acid diffusion control agent is a compound represented by formula (1) described later. [2] The photosensitive or radiation-sensitive resin composition according to [1], wherein the resin comprises repeating units having groups that decompose upon the action of an acid and increase in polarity. [3] The photosensitive or radiation-sensitive resin composition according to [1] or [2], wherein the resin comprises repeating units having phenolic hydroxyl groups. [4] The photosensitive or radiation-sensitive resin composition according to [2], wherein the repeating units having groups that decompose upon the action of an acid and increase in polarity comprises repeating units represented by formula (B1) described later. [5] The photoacid generator generates an acid with a pKa of -2.0 or more and 1.5 or less upon irradiation with active light or radiation, the photoacid generator described in any of [1] to [4]. [6] The Z in formula (1) above. － However, the organic anion represented by formula (a-1) described later is the photosensitive or radiation-sensitive resin composition according to any one of [1] to [5]. [7] The above Z in formula (1) above － [1] to [5] The active photosensitive or radiation-sensitive resin composition according to any one of [1] to [5], wherein the active photosensitive or radiation-sensitive resin composition according to any one of [1] to [7] is characterized in that the content of the acid diffusion control agent relative to the photoacid generator is 50 mol% or more. [9] The active photosensitive or radiation-sensitive resin composition according to any one of [1] to [8] is characterized in that the content of the acid diffusion control agent relative to the photoacid generator is 100 mol% or more.

[10] An active photosensitive or radiation-sensitive film formed using the active photosensitive or radiation-sensitive resin composition according to any one of [1] to [9].

[11] A pattern forming method comprising the steps of: forming a resist film on a substrate using the active photosensitive or radiation-sensitive resin composition according to any one of [1] to [9]; exposing the resist film; and developing the exposed resist film using a developer.

[12] A method for manufacturing an electronic device, comprising the pattern forming method described in

[11] .

[0011] According to the present invention, it is possible to provide a photosensitive or radiation-sensitive resin composition that has little dependence on the heating temperature before development after exposure. Therefore, the object of the present invention is to provide a photosensitive or radiation-sensitive resin composition that has little dependence on the heating temperature before development after exposure. Furthermore, according to the present invention, it is possible to provide a resist film, a pattern formation method, and a method for manufacturing an electronic device relating to the above-mentioned photosensitive or radiation-sensitive resin composition.

[0012] The present invention will be described in detail below. The following descriptions of constituent elements may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.

[0013] In this specification, a numerical range expressed using "~" means a range that includes the numbers written before and after "~" as the lower and upper limits. Also in this specification, if there are two or more types of a component, the "content" of that component means the total content of those two or more types of components. In this specification, in numerical ranges described in steps, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in steps. Also, in numerical ranges described in this specification, the upper or lower limit stated in one numerical range may be replaced with the value shown in the example. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment.

[0014] In this specification, "active light" or "radiation" means, for example, the emission spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light (EUV), X-rays, soft X-rays, and electron beams (EB). In this specification, "light" means active light or radiation. In this specification, unless otherwise specified, "exposure" includes not only exposure with emission spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light, and X-rays, but also drawing with particle beams such as electron beams and ion beams.

[0015] In this specification, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity (also called molecular weight distribution) (Mw / Mn) of a resin are defined as polystyrene equivalent values ​​obtained by GPC (Gel Permeation Chromatography) measurement using a GPC (Gel Permeation Chromatography) instrument (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection volume): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40°C, flow rate: 1.0 mL / min, detector: differential refractive index detector).

[0016] In this specification, the acid dissociation constant (pKa) refers to the pKa in aqueous solution, and specifically, it is a value calculated using the software package 1 described below, based on a database of Hammett substituent constants and known literature values. All pKa values ​​described in this specification are values ​​calculated using this software package. Software package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0017] Furthermore, pKa can also be determined by molecular orbital calculations. Specifically, this method involves calculating the H₂ in aqueous solution based on the thermodynamic cycle. ＋ One method is to calculate the dissociation free energy. ＋ The dissociation free energy can be calculated using, for example, the Density Functional Theory (DFT), but various other methods have been reported in the literature and are not limited to this. Several software programs exist that can perform DFT, such as Gaussian 16.

[0018] In this specification, pKa refers to a value calculated using software package 1 based on a database of Hammett substituent constants and known literature values, as described above. However, if pKa cannot be calculated using this method, the value obtained by Gaussian 16 based on DFT (density functional theory) shall be adopted. In this specification, pKa refers to "pKa in aqueous solution" as described above. However, if pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" shall be adopted.

[0019] In this specification, when there are multiple substituents and linking groups (hereinafter referred to as substituents, etc.) indicated by specific symbols, or when multiple substituents, etc. are specified simultaneously, it means that each substituent, etc. may be identical or different from the others. The same applies to the specification of the number of substituents, etc. In this specification, the bonding direction of a divalent group (e.g., -COO-) as expressed is not limited unless otherwise specified. For example, in a compound represented by the formula "X-Y-Z", if Y is -COO-, the compound may be "X-O-CO-Z" or "X-CO-O-Z".

[0020] In this specification, unless otherwise specified, monovalent substituents are preferred. Examples of substituents include monovalent nonmetallic groups excluding hydrogen atoms, and can be selected from the following substituent T, for example. In this specification, when referring to an aromatic ring group, for example, a group obtained by removing one or more hydrogen atoms from an aromatic ring is included. For example, an n-valent aromatic ring group is a group obtained by removing n hydrogen atoms from an aromatic ring. In this specification, when referring to an aromatic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from the above aromatic hydrocarbon ring is included, and when referring to an aromatic heterocyclic group, a group obtained by removing one or more hydrogen atoms from the above aromatic heterocyclic ring is included.

[0021] (Substituent T) Substituents T include halogen atoms such as fluorine, chlorine, bromine, and iodine; alkoxy groups such as methoxy, ethoxy, and tert-butoxy; cycloalkyloxy groups; aryloxy groups such as phenoxy and p-tolyloxy; alkoxycarbonyl groups such as methoxycarbonyl and butoxycarbonyl; cycloalkyloxycarbonyl groups; aryloxycarbonyl groups such as phenoxycarbonyl; acyloxy groups such as acetoxy, propionyloxy, and benzoyloxy; acetyl, benzoyl, isobutyryl, acryloyl, and meta Examples of substituents include acyl groups such as kryloyl 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; hydroxyl groups; carboxyl groups; formyl groups; sulfo groups; cyano groups; alkylaminocarbonyl groups; arylaminocarbonyl groups; sulfonamide groups; silyl groups; amino groups; carbamoyl groups; and so on. Furthermore, if these substituents can have one or more substituents, groups having one or more substituents selected from the substituents listed above as further substituents (for example, monoalkylamino groups, dialkylamino groups, arylamino groups, trifluoromethyl groups, etc.) are also included as examples of substituent T.

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

[0023] In this specification, "solids" refers to the components that form the resist film and does not include solvents. Furthermore, any component that forms the resist film is considered a solid, even if its state is liquid.

[0024] [Photosensitive or Radiation-Sensitive Resin Composition] The photosensitive or radiation-sensitive resin composition of the present invention (hereinafter also referred to as the "resist composition") is a photosensitive or radiation-sensitive resin composition comprising a resin, a photoacid generator, and an acid diffusion control agent, wherein at least one of the photoacid generator and the acid diffusion control agent is a compound represented by formula (1) (hereinafter also referred to as the "specific sulfonium salt compound"). The present inventors have now, through diligent study, clarified that the resist composition of the present invention having the above configuration exhibits a reduced dependence on the heating temperature before development after exposure. Hereinafter, a reduced dependence on the heating temperature before development after exposure of the resist composition of the present invention is also referred to as "the effect of the present invention is superior."

[0025] [Specific Sulfonium Salt Compound] The resist composition of the present invention comprises a photoacid generator and an acid diffusion control agent, wherein at least one of the photoacid generator and the acid diffusion control agent is a compound represented by formula (1) (specific sulfonium salt compound). Hereinafter, the specific sulfonium salt compound that is the photoacid generator will also be referred to as "specific sulfonium salt compound A," and the specific sulfonium salt compound that is the acid diffusion control agent will also be referred to as "specific sulfonium salt compound B." The acid generated from specific sulfonium salt compound A by irradiation (exposure) with active light or radiation (Z in formula (1)) － The upper limit of the pKa of the organic cation represented by (ZH) is preferably 2.0 or less, more preferably 1.5 or less, even more preferably 1.0 or less, and particularly preferably -0.5 or less. The lower limit of the above pKa is preferably -5.0 or more, more preferably -4.5 or more, and even more preferably -2.0 or more. The acid generated from the specific sulfonium salt compound B by irradiation (exposure) with active light or radiation (ZH in formula (1)) － This corresponds to the proton form (ZH) of the organic cation represented by . The lower limit of the pKa is preferably 1.0 or higher, more preferably 2.0 or higher, and even more preferably 2.50 or higher. The upper limit of the above pKa is preferably 15.0 or lower, more preferably 14.0 or lower, and even more preferably 13.0 or lower.

[0026] Hereinafter, the specific sulfonium salt compound will be described in detail. The specific sulfonium salt compound is a compound represented by the following formula (1).

[0027]

[0028] In the formula, Ar １ ~Ar ３ each independently represents a monovalent aromatic ring group which may have a substituent or an alkyl group which may have a substituent. However, at least one of Ar １ ~Ar ３ represents a monovalent nitrogen-containing aromatic ring group which may have a substituent or a group represented by the formula (2). Note that two of Ar １ ~Ar ３ may be bonded to each other via a single bond or a divalent linking group. Z － represents an anion. However, the above anion does not contain *-C(R Ｆ１ )(R Ｆ２ )-SO ３ － . R Ｆ１ and R Ｆ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. * represents the bonding position.

[0029]

[0030] In the formula, Ar ４ represents an l+1-valent aromatic ring group which may have a substituent other than the group represented by -N(R Ｔ３ )(R Ｔ４ ). R Ｔ３ and R Ｔ４ each independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group which may have a substituent other than an acid-decomposable group, a monovalent aromatic ring group which may have a substituent other than an acid-decomposable group, or a monovalent aliphatic heterocyclic group which may have a substituent other than an acid-decomposable group. Note that R Ｔ３ and R Ｔ４ may be bonded to each other to form a ring which may have a substituent. The wavy line represents the bonding position. Note that when there are a plurality of R Ｔ３ , the plurality of R Ｔ３ may be the same as or different from each other. R Ｔ４If there are multiple instances of R, then there are multiple instances of R Ｔ４ The terms may be identical or different from each other. l represents an integer greater than or equal to 1.

[0031] In formula (1), Ar １ ~Ar ３ Each of these independently represents a potentially substituted monovalent aromatic ring group or a potentially substituted alkyl group.

[0032] The above aromatic ring group may be monocyclic or polycyclic, with monocyclic being preferred. The above aromatic ring group may be either an aromatic hydrocarbon group or an aromatic heterocyclic group, with aromatic hydrocarbon groups being preferred. Examples of the above aromatic hydrocarbon group include groups containing aromatic hydrocarbon rings having 6 to 18 carbon atoms, such as benzene, naphthalene, anthracene, and naphthacene. The above aromatic heterocyclic group preferably contains at least one heteroatom selected from nitrogen, oxygen, and sulfur atoms as a ring member atom. Examples of aromatic heterocyclic groups include groups containing aromatic heterocyclic rings having 4 to 20 ring member atoms, such as thiophene, furan, pyridine, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole.

[0033] Ar １ ~Ar ３Examples of substituents that the monovalent aromatic ring group represented by may have include the substituent T mentioned above, alkyl groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), cycloalkyl groups (e.g., 3 to 15 carbon atoms, preferably 3 to 6 carbon atoms), aromatic ring groups (e.g., 3 to 12 carbon atoms; in the case of aromatic heterocyclic groups, specific examples of ring member atoms include sulfur atoms, nitrogen atoms, and oxygen atoms), alkoxy groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), aryloxy groups (e.g., 6 to 14 carbon atoms), alkylthio groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), arylthio groups (e.g., 6 to 14 carbon atoms), 14) Preferred substituents are acyloxy (e.g., 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms), alkoxycarbonyl groups (e.g., 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms), mono or dialkylamino groups (the number of carbon atoms in the alkyl group is, for example, 1 to 15, preferably 1 to 6 carbon atoms), mono or diarylamino groups (the number of carbon atoms in the aryl group is, for example, 6 to 14 carbon atoms), hydroxyl groups, carboxyl groups, cycloalkyloxycarbonyl groups (e.g., 4 to 15 carbon atoms, preferably 4 to 8 carbon atoms), aryloxycarbonyl groups (e.g., 7 to 15 carbon atoms, preferably 7 to 8 carbon atoms), or heteroaryloxy groups (e.g., 5 or 6 ring members). The groups exemplified above as substituents may have further substituents if possible.

[0034] Ar １ ~Ar ３ In an alkyl group which may have substituents represented by , the number of carbon atoms of the alkyl group is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. Furthermore, the alkyl group may be linear, branched, or cyclic.

[0035] Ar １ ~Ar ３Examples of substituents that the alkyl group represented by may have include the substituent T mentioned above, aromatic ring groups (e.g., 3 to 12 carbon atoms; in the case of aromatic heterocyclic groups, specific examples of ring member atoms include sulfur, nitrogen, and oxygen atoms), alkoxy groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), aryloxy groups (e.g., 6 to 14 carbon atoms), alkylthio groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), arylthio groups (e.g., 6 to 14 carbon atoms), and acyloxy groups (e.g., 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms). Preferred substituents are alkoxycarbonyl groups (e.g., 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms), mono- or dialkylamino groups (the number of carbon atoms in the alkyl group is, for example, 1 to 15, preferably 1 to 6), mono- or diarylamino groups (the number of carbon atoms in the aryl group is, for example, 6 to 14), hydroxyl groups, carboxyl groups, cycloalkyloxycarbonyl groups (e.g., 4 to 15 carbon atoms, preferably 4 to 8 carbon atoms), aryloxycarbonyl groups (e.g., 7 to 15 carbon atoms, preferably 7 to 8 carbon atoms), or heteroaryloxy groups (e.g., 5 or 6 ring members). The groups exemplified above as substituents may have further substituents if possible.

[0036] In formula (1), Ar １ ~Ar ３ Preferably, each of these independently represents a monovalent aromatic ring group which may have substituents.

[0037] In formula (1), Ar １ ~Ar ３ Two of these may be bonded to each other via a single bond or a divalent linking group. That is, Ar １ ~Ar ３ Two of these may be bonded to each other via a single bond or a divalent linking group to form a ring which may have substituents. Examples of the divalent linking group include -O-, -S-, -CO-, and -NR Ｘ１ -, -SO-, -SO ２- Examples include 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 and alkenylene groups may have substituents. Examples of the substituents include the substituent T mentioned above. Ｘ１ This represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0038] However, in a specific sulfonium salt compound (a compound represented by formula (1)), Ar １ ~Ar ３ At least one of the groups represents a monovalent nitrogen-containing aromatic ring group or a group represented by formula (2), which may have substituents. The nitrogen-containing aromatic ring group may be monocyclic or polycyclic, with monocyclic being preferred. The nitrogen-containing aromatic ring group may contain heteroatoms other than nitrogen atoms (e.g., oxygen atoms and sulfur atoms) as ring member atoms. The number of nitrogen atoms that the nitrogen-containing aromatic ring group has as ring member atoms may be one or more, with 1 to 4 being preferred. Examples of nitrogen-containing aromatic ring groups include groups containing nitrogen-containing aromatic rings with 4 to 20 ring member atoms, such as pyridine, pyrrole, benzopyrrole, triazine, imidazole, benzimidazole, triazole, and thiadiazole. Substituents that the nitrogen-containing aromatic ring group may have include Ar １ ~Ar ３ Examples of substituents that the monovalent aromatic ring group represented by the above may have include the groups exemplified in the upper section.

[0039] In formula (2), Ar ４ is -N(R Ｔ３ ) (Caution Ｔ４This represents an l+1 valent aromatic ring group which may have substituents other than the group represented by ). The above aromatic ring group may be monocyclic or polycyclic, with monocyclic being preferred. The above aromatic ring group may be either an aromatic hydrocarbon group or an aromatic heterocyclic group, with aromatic hydrocarbon groups being preferred. Examples of the above aromatic hydrocarbon group include groups containing aromatic hydrocarbon rings having 6 to 18 carbon atoms, such as benzene, naphthalene, anthracene, and naphthacene. The above aromatic heterocyclic group preferably contains at least one heteroatom selected from nitrogen, oxygen, and sulfur atoms as a ring member atom. Examples of aromatic heterocyclic groups include groups containing aromatic heterocyclic rings having 4 to 20 ring member atoms, such as thiophene, furan, pyridine, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole.

[0040] Ar ４ A 1+1 valent aromatic ring group represented by -N(R Ｔ３ ) (Caution Ｔ４ Other substituents besides the group represented by ) include, for example, the substituent T (wherein -N(R) mentioned above. Ｔ３ ) (Caution Ｔ４Excluding groups corresponding to the group represented by ), examples include alkyl groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), cycloalkyl groups (e.g., 3 to 15 carbon atoms, preferably 3 to 6 carbon atoms), aromatic ring groups (e.g., 3 to 12 carbon atoms; in the case of aromatic heterocyclic groups, specific examples of ring member atoms include sulfur atoms, nitrogen atoms, and oxygen atoms), alkoxy groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), aryloxy groups (e.g., 6 to 14 carbon atoms), and alkylthio groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms). Preferably, the substituents are arylthio groups (e.g., 6 to 14 carbon atoms), acyloxy groups (e.g., 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms), alkoxycarbonyl groups (e.g., 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms), hydroxyl groups, carboxyl groups, cycloalkyloxycarbonyl groups (e.g., 4 to 15 carbon atoms, preferably 4 to 8 carbon atoms), aryloxycarbonyl groups (e.g., 7 to 15 carbon atoms, preferably 7 to 8 carbon atoms), or heteroaryloxy groups (e.g., 5 or 6 ring members). The groups exemplified above as substituents may have further substituents if possible. ４ The 1+1 valent aromatic ring group represented by -N(R Ｔ３ ) (Caution Ｔ４ The number of substituents other than the group represented by ) is preferably 0 to 4, and more preferably 0 to 3.

[0041] In formula (2), R Ｔ３ and R Ｔ４ Each of these independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group which may have substituents other than an acid-degradable group, a monovalent aromatic ring group which may have substituents other than an acid-degradable group, or a monovalent aliphatic heterocyclic group which may have substituents other than an acid-degradable group. Here, an acid-degradable group is a group which decomposes upon the action of an acid to produce a polar group. Acid-degradable groups typically have a structure in which the polar group is protected by a leaving group which is eliminated upon the action of an acid. Specific examples of acid-degradable groups are the same as those shown in the description of resins later in this document.

[0042] R Ｔ３ and R Ｔ４The monovalent aliphatic hydrocarbon group represented by [hereinafter referred to as “(wherein, the alkyl group, alkenyl group, and alkynyl group are exemplified, and an alkyl group is preferable)” may be linear, branched, or cyclic. The number of carbon atoms of the monovalent aliphatic hydrocarbon group is preferably 1 to 20, more preferably 1 to 15, still more preferably 1 to 10, and particularly preferably 1 to 6. R Ｔ３ and R Ｔ４ Examples of the substituent other than the acid-decomposable group that the monovalent aliphatic hydrocarbon group represented by may have include, for example, the above-described substituent T (however, excluding the group corresponding to the acid-decomposable group). An aromatic ring group (for example, having 3 to 12 carbon atoms. In the case of an aromatic heterocyclic group, specific examples of the ring member atoms include a sulfur atom, a nitrogen atom, and an oxygen atom), an alkoxy group (for example, having 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), an aryloxy group (for example, having 6 to 14 carbon atoms), an alkylthio group (for example, having 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), an arylthio group (for example, having 6 to 14 carbon atoms), acyloxy (for example, having 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms), an alkoxycarbonyl group (for example, having 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms), a hydroxy group, a carboxy group, a cycloalkyloxycarbonyl group (for example, having 4 to 15 carbon atoms, preferably 4 to 8 carbon atoms), an aryloxycarbonyl group (for example, having 7 to 15 carbon atoms, preferably 7 to 8 carbon atoms), or a heteroaryloxy group (for example, having 5 or 6 ring members) is preferable. The groups exemplified as the above-described substituents may further have the above-described substituents where possible.

[0043] R Ｔ３ and R Ｔ４ Specific examples of the monovalent aromatic ring group represented by are the same as the monovalent aromatic ring group represented by Ar in Formula (1) １ to Ar ３ and have the same preferred embodiments.

[0044] R Ｔ３ and R Ｔ４The monovalent aliphatic heterocyclic group represented by may be either monocyclic or polycyclic, with the monocyclic form being preferred. The above aliphatic heterocyclic group preferably contains at least one heteroatom selected from a nitrogen atom, an oxygen atom, and a sulfur atom as ring members. Examples of the aliphatic heterocyclic group include groups containing aliphatic heterocycles with 4 to 20 ring member atoms such as pyrrolidine, piperidine, piperazine, morpholine, tetrahydrofuran, dioxane, and dioxolane. Note that in the aliphatic heterocycle, a part of the ring member atoms may be substituted with atomic groups such as >C=O and >S(=O). ２ It may also be substituted with atomic groups such as those described above.

[0045] R Ｔ３ and R Ｔ４ Examples of the substituents other than the acid-degradable group that the monovalent aromatic ring group and the monovalent aliphatic heterocyclic group represented by may have include, for example, the above-described substituent T (excluding groups corresponding to the acid-degradable group). Examples include an alkyl group (e.g., having 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), a cycloalkyl group (e.g., having 3 to 15 carbon atoms, preferably 3 to 6 carbon atoms), an aromatic ring group (e.g., having 3 to 12 carbon atoms. In the case of an aromatic heterocyclic group, specific examples of the ring member atoms include a sulfur atom, a nitrogen atom, and an oxygen atom), an alkoxy group (e.g., having 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), an aryloxy group (e.g., having 6 to 14 carbon atoms), an alkylthio group (e.g., having 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), an arylthio group (e.g., having 6 to 14 carbon atoms), an acyloxy (e.g., having 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms), an alkoxycarbonyl group (e.g., having 2 to 15 carbon atoms, preferably 2 to 6 carbon atoms), a hydroxy group, a carboxy group, a cycloalkyloxycarbonyl group (e.g., having 4 to 15 carbon atoms, preferably 4 to 8 carbon atoms), an aryloxycarbonyl group (e.g., having 7 to 15 carbon atoms, preferably 7 to 8 carbon atoms), or a heteroaryloxy group (e.g., having 5 or 6 ring members). The groups exemplified as the above substituents may further have the above substituents where possible.

[0046] In formula (2), R Ｔ３ and R Ｔ４ may be bonded to each other to form a ring that may have a substituent. Here, R Ｔ３ and R Ｔ４The above ring formed by the combination is a ring containing a nitrogen atom (Ar ４ intended to be the nitrogen atom bonded to.) explicitly shown in formula (2) as a ring member atom, and may be either an aromatic ring or a non-aromatic ring. That is, the above ring may be either a nitrogen-containing aromatic ring or a nitrogen-containing aliphatic ring. Further, the above ring may be either a monocyclic ring or a polycyclic ring. Further, the above ring may further contain heteroatoms other than nitrogen atoms (for example, oxygen atoms and sulfur atoms), and part of the ring member atoms are >C=O, and >S(=O) ２ and the like may be substituted with atomic groups. Specific examples of the above nitrogen-containing aromatic ring include rings having 4 to 20 (preferably 5 or 6) ring member atoms such as pyridine, pyrrole, benzopyrrole, triazine, imidazole, benzimidazole, triazole, and thiadiazole. Specific examples of the above nitrogen-containing aliphatic ring include rings having 4 to 20 (preferably 5 or 6) ring member atoms such as pyrrolidine, piperidine, piperazine, and morpholine. Examples of the substituent that the above ring may have include the groups exemplified in the upper part as the substituent that the monovalent aromatic ring group represented by Ar １ to Ar ３ may have.

[0047] In formula (2), when there are a plurality of R Ｔ３ , the plurality of R Ｔ３ may be the same as or different from each other. When there are a plurality of R Ｔ４ , the plurality of R Ｔ４ may be the same as or different from each other.

[0048] In formula (2), R Ｔ３ and R Ｔ４ represent at least one of a monovalent aliphatic hydrocarbon group that may have a substituent other than an acid-decomposable group, a monovalent aromatic ring group that may have a substituent other than an acid-decomposable group, or a monovalent aliphatic heterocyclic group that may have a substituent other than an acid-decomposable group, or R Ｔ３ and R Ｔ４ are preferably bonded to each other to form a ring that may have a substituent.

[0049] In formula (2), l represents an integer of 1 or more. l is preferably an integer of 1 to 3, more preferably 1 or 2, and still more preferably 1.

[0050] Z in formula (1) － represents an anion. The anion represented by Z － will be described in the latter part.

[0051] As an example of a preferred embodiment of the specific sulfonium salt compound (the compound represented by formula (1)), for example, the compound represented by formula (1A) and the compound represented by formula (1B) can be mentioned.

[0052]

[0053] In formula (1A), Ar １Ａ ~Ar ３Ａ each independently represents a monovalent aromatic ring group which may have a substituent. However, at least one of Ar １Ａ ~Ar ３Ａ represents a monovalent nitrogen-containing aromatic ring group which may have a substituent or a group represented by formula (2). Also, Ar １Ａ and Ar ２Ａ , Ar １Ａ and Ar ３Ａ , and Ar ２Ａ and Ar ３Ａ are not bonded to each other via a single bond and a divalent linking group. In formula (1A), Z － is synonymous with Z in formula (1) － and the preferred embodiments are also the same.

[0054] The monovalent aromatic ring group which may have a substituent represented by Ar １Ａ ~Ar ３Ａ in formula (1A) is synonymous with the monovalent aromatic ring group which may have a substituent represented by Ar １ ~Ar ３ in formula (1), and the preferred embodiments are also the same. The monovalent nitrogen-containing aromatic ring group which may have a substituent and the group represented by formula (2) represented by at least one of Ar １Ａ ~Ar ３Ａ in formula (1A) are the same as those represented by at least one of Ar １ ~Ar ３This is synonymous with a monovalent nitrogen-containing aromatic ring group which may have substituents, and a group represented by formula (2), and the preferred embodiments are the same.

[0055]

[0056] In formula (1B), Ar １Ｂ Ar represents a monovalent nitrogen-containing aromatic ring group which may have substituents, or a group represented by formula (2). ２Ｂ and Ar ３Ｂ Each of these independently represents a divalent aromatic ring group which may have substituents. １Ｂ represents a single bond or a divalent linking group. In formula (1B), Z － This is Z in equation (1). － This is synonymous with the same thing, and the preferred embodiment is also the same.

[0057] Ar in equation (1B) １Ｂ The monovalent nitrogen-containing aromatic ring group, which may have substituents, and the group represented by formula (2) are the Ar groups in formula (1). １ ~Ar ３ This is synonymous with a monovalent nitrogen-containing aromatic ring group which may have substituents, and a group represented by formula (2), and the preferred embodiments are the same.

[0058] Ar in equation (1B) ２Ｂ and Ar ３Ｂ A divalent aromatic ring group which may have substituents, represented by the above formula (1), is Ar １ ~Ar ３ Examples of monovalent aromatic ring groups that may have substituents represented by include the group obtained by removing one hydrogen atom from the exemplified group.

[0059] In formula (1B), Y １Ｂ - represents a single bond or a divalent linking group. Examples of the above divalent linking groups are -O-, -S-, -CO-, and -NR. Ｘ１ -, -SO-, -SO ２- Examples include 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 and alkenylene groups may have substituents. Examples of the substituents include the substituent T mentioned above. Ｘ１ Y represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. １Ｂ The bond is preferably a single bond, -O-, -S-, or -NH-.

[0060] In formula (1B), Ar １Ｂ It is preferable that this represents the group represented by formula (2).

[0061] An example of a preferred embodiment of formula (1B) is a compound represented by formula (1B').

[0062]

[0063] In formula (1B'), Z － This is Z in equation (1). － This is synonymous with the same as the preferred embodiment. In formula (1B'), Y ２Ｂ Y in equation (1B) １Ｂ This is synonymous with the same as the preferred embodiment. In formula (1B'), R ２１ ~R ３３ R represents a hydrogen atom or substituent. ２１ ~R ２５ At least one of these (preferably one or two, more preferably one) represents a group represented by formula (2X).

[0064] Formula (2X) *-N(R Ｔ３ ) (Caution Ｔ４ ) R in equation (2X) Ｔ３ and R Ｔ４ R in equation (2) Ｔ３ and R Ｔ４ This is synonymous with the same thing, and the preferred embodiment is also the same.

[0065] R ２１ ~R ３３Other substituents than the group represented by formula (2) include the substituent T mentioned above, which includes alkyl groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), cycloalkyl groups (e.g., 3 to 15 carbon atoms, preferably 3 to 6 carbon atoms), aromatic ring groups (e.g., 3 to 12 carbon atoms; in the case of aromatic heterocyclic groups, specific examples of ring member atoms include sulfur atoms, nitrogen atoms, and oxygen atoms), alkoxy groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), aryloxy groups (e.g., 6 to 14 carbon atoms), and alkylthio groups (e.g., 1 carbon atom). Preferably, R is a hydroxyl group (e.g., 1-15 carbon atoms, preferably 1-6 carbon atoms), an arylthio group (e.g., 6-14 carbon atoms), an acyloxy group (e.g., 2-15 carbon atoms, preferably 2-6 carbon atoms), an alkoxycarbonyl group (e.g., 2-15 carbon atoms, preferably 2-6 carbon atoms), a hydroxyl group, a carboxyl group, a cycloalkyloxycarbonyl group (e.g., 4-15 carbon atoms, preferably 4-8 carbon atoms), an aryloxycarbonyl group (e.g., 7-15 carbon atoms, preferably 7-8 carbon atoms), or a heteroaryloxy group (e.g., 5 or 6 ring members). The groups exemplified above as substituents may have further substituents if possible. In formula (1B'), R ２１ ~R ３３ The adjacent groups may bond to each other to form a ring which may have substituents. The ring may be either an aromatic ring or a non-aromatic ring, and may be monocyclic or polycyclic. The ring may also further contain heteroatoms (e.g., nitrogen, oxygen, and sulfur atoms), and some of the ring member atoms may be >C=O and >S(=O). ２ They may be substituted with atomic groups such as the following.

[0066] Specific examples of sulfonium cations in specific sulfonium salt compounds are given, but the invention is not limited thereto.

[0067]

[0068]

[0069] Below, Z in equation (1) － We will explain the anion represented by equation (1). － This represents an anion. However, Z －is *-C(R Ｆ１ ) (Caution Ｆ２ ) - SO ３ － It does not include the structural part represented by R. Ｆ１ and R Ｆ２ Each of these independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. * indicates the bond position. Z － Furthermore, *-C(R Ｆ３ ) (Caution Ｆ４ ) - SO ３ － It is also preferable that the structural part represented by R is not included. Ｆ３ and R Ｆ４ Each of these independently represents either a fluorine atom or a perfluoroalkyl group. Below, we will explain separately the anions that can constitute specific sulfonium salt compound A and the anions that can constitute specific sulfonium salt compound B.

[0070] (Anions that can constitute specific sulfonium salt compound A) The anions that can constitute specific sulfonium salt compound A may be monovalent or polyvalent (2 or more) anions, but monovalent anions are preferred. The anions that can constitute specific sulfonium salt compound A may be inorganic or organic anions, but organic anions are preferred. The organic anions that can constitute specific sulfonium salt compound A are preferably organic anions with a remarkably low ability to undergo nucleophilic reactions, and non-nucleophilic organic anions (hereinafter also referred to as "non-nucleophilic anions") are more preferred.

[0071] Examples of non-nucleophilic anions include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, and camphor sulfonate anions, etc.), carboxylic acid anions (aliphatic carboxylic acid anions, aromatic carboxylic acid anions, and aralkyl carboxylic acid anions, etc.), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

[0072] The aliphatic moiety in the aliphatic sulfonate anion may be a linear or branched alkyl group or a cycloalkyl group, and a linear or branched alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms is preferred. The above alkyl group and cycloalkyl group may be, for example, a fluoroalkyl group in which a part of the hydrogen atoms is substituted with fluorine atoms.

[0073] The aliphatic moiety in the aliphatic carboxylate anion may be a linear or branched alkyl group or a cycloalkyl group, and a linear or branched alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms is preferred. The above alkyl group and cycloalkyl group may be, for example, a fluoroalkyl group in which part or all of the hydrogen atoms are substituted with fluorine atoms.

[0074] As the aryl group in the aromatic sulfonate anion and the aromatic carboxylate anion, an aryl group having 6 to 14 carbon atoms is preferred, and examples include a phenyl group, a tolyl group, and a naphthyl group.

[0075] The alkyl group, cycloalkyl group, and aryl group mentioned above may have substituents. Examples of the substituents include a nitro group, halogen atoms such as a fluorine atom and a chlorine atom, a carboxy group, a hydroxy 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).

[0076] In aralkyl carboxylate anions, aralkyl groups having 7 to 14 carbon atoms are preferred. Examples of aralkyl groups having 7 to 14 carbon atoms include benzyl, phenethyl, naphthylmethyl, naphthylethyl, and naphthylbutyl groups.

[0077] An example of a sulfonylimid anion is the saccharin anion.

[0078] In bis(alkylsulfonyl)imido anions and tris(alkylsulfonyl)methide anions, alkyl groups having 1 to 5 carbon atoms are preferred. Substituents for these alkyl groups include halogen atoms, halogen-substituted alkyl groups, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, and cycloalkylaryloxysulfonyl groups, with fluorine atoms or fluorine-substituted alkyl groups being preferred. Furthermore, the alkyl groups in bis(alkylsulfonyl)imido anions may be bonded to each other to form a ring structure.

[0079] As a non-nucleophilic anion, the anion represented by the following formula (AN1) is also preferred.

[0080]

[0081] In formula (AN1), R １ and R ２ Each of these independently represents a hydrogen atom or a substituent. Examples of substituents include hydrocarbon groups, hydroxyl groups, oxy hydrocarbon groups, oxycarbonyl hydrocarbon groups, amino groups, hydrocarbon-substituted amino groups, and hydrocarbon-substituted amide groups, and are -R', -OH, -OR', -OCOR', -NH ２ ,-NR' ２ -NHR' or -NHCOR' is preferred. R' is a monovalent hydrocarbon group. Among them, R １ and R ２ Each of these is independently preferably a hydrocarbon group (cycloalkyl group is preferred) or a hydrogen atom.

[0082] Examples of monovalent hydrocarbon groups represented by R' above include alkyl groups such as methyl, ethyl, propyl, and butyl groups; alkenyl groups such as ethenyl, propenyl, and butenyl groups; monovalent linear or branched hydrocarbon groups such as alkynyl groups such as ethynyl, propynyl, and butynyl groups; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl groups; monovalent alicyclic hydrocarbon groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and norbornenyl groups; aryl groups such as phenyl, tolyl, xylyl, mesityl, naphthyl, methylnaphthyl, anthryl, and methylanthryl groups; and monovalent aromatic hydrocarbon groups such as benzyl, phenethyl, phenylpropyl, naphthylmethyl, and anthrylmethyl groups.

[0083] L represents a divalent linking group. Examples of divalent linking groups include -CO-, -NH-, -O-, -S-, -SO-, and -SO ２ Examples of divalent linking groups include alkylene groups (preferably having 1 to 6 carbon atoms), cycloalkylene groups (preferably having 3 to 15 carbon atoms), alkenylene groups (preferably having 2 to 6 carbon atoms), and divalent linking groups formed by combining multiples thereof. Among these, examples of divalent linking groups include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, and -SO ２ -, -O-CO-O-alkylene group-, -COO-alkylene group-, or -CONH-alkylene group- are preferred, and -O-CO-O-, -O-CO-O-alkylene group-, -COO-, -CONH-, -SO ２ - or -COO-alkylene group- is more preferred.

[0084] For L, a group represented by the following formula (AN1-1) is preferred. * ａ - (CR ２ａ ２ ) Ｘ -Q- (CR ２ｂ ２ ) Ｙ - * ｂ (AN1-1)

[0085] In formula (AN1-1), * ａ R in equation (AN1) ３ This indicates the connection point with [the other element]. * ｂ -C(R) in equation (AN1) １ ) (Caution ２ ) - Represents the connection position with . X and Y each independently represent integers from 0 to 10, preferably integers from 0 to 3. R ２ａ and R ２ｂ Each of these independently represents a hydrogen atom or a substituent. ２ａ and R ２ｂ If there are multiple instances of each, then there are multiple instances of R ２ａ and R ２ｂ These may be the same or different. However, if Y is 1 or greater, -C(R) in equation (AN1) １ ) (Caution ２ )- and CR that bind directly ２ｂ ２ In R ２ｂ is anything 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 This represents the condition that X+Y in equation (AN1-1) is 1 or greater, and R in equation (AN1-1) is greater than or equal to 1. ２ａ and R ２ｂ If all of them are hydrogen atoms, then 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 This represents. * Ａ R in equation (AN1) ３ This indicates the connection position on the side, * Ｂ This is -SO in equation (AN1). ３ － This indicates the connection point on the side.

[0086] In formula (AN1), R ３ R represents an organic group. The above organic group is not particularly limited and may be a linear group (e.g., a linear alkyl group), a branched group (e.g., a branched alkyl group such as a t-butyl group), or a cyclic group. The above organic group may have substituents and may have heteroatoms (oxygen atom, sulfur atom, and / or nitrogen atom, etc.). Among these, R ３ It is preferable that the organic group has a cyclic structure. The cyclic structure may be monocyclic or polycyclic and may have substituents. It is preferable that the ring in the organic group containing the cyclic structure is directly bonded to L in formula (AN1). The organic group having the cyclic structure may have, for example, heteroatoms (oxygen atom, sulfur atom, and / or nitrogen atom). The heteroatoms may be substituted for one or more carbon atoms forming the cyclic structure.

[0087] The organic group having the above-mentioned cyclic structure is preferably a cyclic hydrocarbon group, a lactone ring group, or a sultone ring group, with a cyclic hydrocarbon group being more preferred. The above-mentioned cyclic hydrocarbon group is preferably a monocyclic or polycyclic cycloalkyl group. These groups may have substituents. The above-mentioned cycloalkyl group may be monocyclic (e.g., a cyclohexyl group) or polycyclic (e.g., an adamantyl group), and the number of carbon atoms is preferably 5 to 12.

[0088] R ３ It is preferable that it contains a halogen atom. ３ The halogen atoms included are preferably fluorine atoms or iodine atoms, with iodine atoms being more preferred. If iodine atoms are present, a structure in which they are directly bonded to carbon atoms on the aromatic ring is preferred. When the resist composition of the present invention is used as an EUV resist, a larger number of halogen atoms is preferable from the viewpoint of EUV light absorption efficiency.

[0089] Examples of anions represented by formula (AN1) include those described in

[0040] to

[0044] of Japanese Patent Publication No. 2018-155908,

[0184] to

[0185] and

[0197] to

[0198] of Japanese Patent Publication No. 2021-128331,

[0124] to

[0125] and

[0137] to

[0138] of International Publication No. 2022 / 064863, and

[0056] to

[0061] of Japanese Patent Publication No. 2023-177048, the above descriptions are incorporated herein by reference.

[0090] As a non-nucleophilic anion, the anion represented by the following formula (AN2) is also preferred.

[0091]

[0092] In formula (AN2), o represents an integer from 1 to 3. p represents an integer from 0 to 10. q represents an integer from 0 to 10. L represents a divalent linking group. The definition of L is the same as that of L in formula (AN1).

[0093] Xf represents a hydrogen atom, a fluorine atom, an alkyl group substituted with one or more fluorine atoms, or an organic group without a fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, and more preferably 1 to 4. As the alkyl group substituted with one or more fluorine atoms, a perfluoroalkyl group is preferred. However, -SO as explicitly stated in formula (AN2) ３ － In an adjacent -C(Xf)(Xf)- group, it is not possible for both Xf atoms to simultaneously be a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. In other words, if one of the two Xf atoms represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms, the other represents a group other than a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. -SO as explicitly shown in formula (AN2) ３ － In the adjacent -C(Xf)(Xf)- group, it is also preferable that one Xf represents a hydrogen atom, a fluorine atom, an alkyl group substituted with one or more fluorine atoms, or an organic group without a fluorine atom, while the other represents an organic group without a hydrogen atom or a fluorine atom.

[0094] R４ and R ５ Each of these independently represents a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with one or more fluorine atoms. ４ and R ５ If multiple instances exist, R ４ and R ５ These may be the same or different. ４ and R ５ The alkyl group represented by preferably has 1 to 4 carbon atoms. The alkyl group may have substituents. ４ and R ５ A hydrogen atom is preferred as the element.

[0095] W represents an organic group containing a cyclic structure. Among these, a cyclic organic group is preferred. The carbon atoms constituting the cyclic organic group (carbon atoms contributing to ring formation) may be carbonyl carbons. Examples of cyclic organic groups include alicyclic groups, aryl groups, and heterocyclic groups. Alicyclic groups may be monocyclic or polycyclic. Examples of monocyclic alicyclic groups include monocyclic cycloalkyl groups such as cyclopentyl groups, cyclohexyl groups, and cyclooctyl groups. Examples of polycyclic alicyclic groups include polycyclic cycloalkyl groups such as norbornyl groups, tricyclodecanyl groups, tetracyclodecanyl groups, tetracyclododecanyl groups, and adamantyl groups. Among these, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as norbornyl groups, tricyclodecanyl groups, tetracyclodecanyl groups, tetracyclododecanyl groups, and adamantyl groups, are preferred.

[0096] The aryl group may be monocyclic or polycyclic. Examples of the above aryl group include the phenyl group, naphthyl group, phenanthryl group, and anthryl group. The heterocyclic group may be monocyclic or polycyclic. The heterocyclic group may or may not be aromatic. Examples of aromatic heterocyclic rings include the furan ring, thiophene ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, and pyridine ring. Examples of heterocyclic rings that are not aromatic include the tetrahydropyran ring, lactone ring, sultone ring, and decahydroisoquinoline ring. The heterocyclic ring in the heterocyclic group is preferably a furan ring, thiophene ring, pyridine ring, or decahydroisoquinoline ring.

[0097] The above-mentioned cyclic organic group may have substituents. Examples of substituents include alkyl groups (which may be linear or branched, preferably having 1 to 12 carbon atoms), cycloalkyl groups (which may be monocyclic, polycyclic, or spirocyclic, preferably having 3 to 20 carbon atoms), aryl groups (preferably having 6 to 14 carbon atoms), hydroxyl groups, alkoxy groups, ester groups, amide groups, urethane groups, ureido groups, thioether groups, sulfonamide groups, and sulfonic acid ester groups.

[0098] It is preferable that W contains halogen atoms. Preferably, the halogen atoms in W are fluorine atoms or iodine atoms, with iodine atoms being more preferable. If iodine atoms are present, a structure in which they are directly bonded to carbon atoms on an aromatic ring is preferred. When the resist composition of the present invention is used as an EUV resist, a larger number of halogen atoms is preferable from the viewpoint of EUV light absorption efficiency.

[0099] Anions represented by formula (AN2) include

[0076] in International Publication No. 2023 / 157455,

[0071] to

[0089] in Japanese Patent Publication No. 2021-081708,

[0033] to

[0045] in Japanese Patent Publication No. 2018-005224,

[0031] to

[0039] in Japanese Patent Publication No. 2018-025789, and Japanese Patent Publication No. 2021 Examples include the anions described in

[0176] to

[0183] and

[0186] to

[0196] of Publication No. 128331,

[0116] to

[0123] and

[0126] to

[0136] of International Publication No. 2022 / 064863, and

[0076] of International Publication No. 2023 / 157455, which are incorporated herein by reference.

[0100] As a non-nucleophilic anion, an aromatic sulfonic acid anion represented by the following formula (AN3) is also preferred.

[0101]

[0102] In formula (AN3), Ar represents an aryl group (such as a phenyl group) and may further have substituents other than a sulfonic acid anion and a -(D-B) group. Examples of further substituents include a fluorine atom and a hydroxyl group. n represents an integer of 0 or more. n is preferably 1 to 4, more preferably 2 to 3, and even more preferably 3.

[0103] D represents a single bond or a divalent linking group. Examples of divalent linking groups include ether groups, thioether groups, carbonyl groups, sulfoxide groups, sulfone groups, sulfonic acid ester groups, ester groups, and groups consisting of two or more combinations thereof.

[0104] B represents a hydrocarbon group which may have substituents. B is preferably an aliphatic hydrocarbon group, and more preferably an isopropyl group, a cyclohexyl group, or an aryl group which may have further substituents (such as a tricyclohexylphenyl group).

[0105] It is preferable that B contains halogen atoms. Preferably, the halogen atoms in B are fluorine atoms or iodine atoms, with iodine atoms being more preferable. If iodine atoms are present, a structure in which they are directly bonded to carbon atoms on an aromatic ring is preferred. When the resist composition is used as an EUV resist, a larger number of halogen atoms is preferable from the viewpoint of EUV light absorption efficiency.

[0106] Examples of anions represented by formula (AN3) include those described in

[0029] to

[0034] of Japanese Patent Publication No. 2018-159744,

[0045] of Japanese Patent Publication No. 2018-155908,

[0037] to

[0055] and

[0062] to

[0064] of Japanese Patent Publication No. 2023-177048, the above descriptions are incorporated herein by reference.

[0107] As a non-nucleophilic anion, disulfonamide anions are also preferred. Disulfonamide anions include, for example, N － (SO ２ -R ｑ ) ２ This is an anion represented by R. ｑ R represents an alkyl group which may have substituents, preferably a fluoroalkyl group, and more preferably a perfluoroalkyl group. ｑ They may be joined to each other to form a ring. Two R ｑ The group formed by the bonding of these atoms is preferably an alkylene group, which may have substituents, preferably a fluoroalkylene group, and more preferably a perfluoroalkylene group. The alkylene group preferably has 2 to 4 carbon atoms.

[0108] Furthermore, non-nucleophilic anions include those represented by the following formulas (d1-1) to (d1-4).

[0109]

[0110] In formula (d1-1), R ５１represents a hydrocarbon group (e.g., an aryl group such as a phenyl group) which may have substituents (e.g., a hydroxyl group). Examples of anions represented by formula (d1-1) include

[0041] to

[0047] in JP 2017-219836,

[0026] to

[0028] in JP 2018-155902,

[0040] to

[0041] and

[0128] in JP 2020-154212,

[0049] to

[0061] and

[0278] to

[0279] in JP 2021-091666, and International Publication No. 2022 / Examples of anions described in

[0150] to

[0154] of JP 064863,

[0013] to

[0015] of JP 2022-077505,

[0026] to

[0031] and

[0050] to

[0051] of JP 2022-141598,

[0147] of JP 2023-108593, and

[0088] of International Publication No. 2023 / 157455 are included, and the above descriptions are incorporated herein by reference.

[0111] In formula (d1-2), Z ２ｃ represents a hydrocarbon group having 1 to 30 carbon atoms, which may have substituents (however, carbon atoms adjacent to S are not substituted with fluorine atoms). ２ｃ The hydrocarbon group in the above may be linear, branched, or have a cyclic structure. Furthermore, the carbon atoms in the hydrocarbon group (preferably, the ring member carbon atoms when the hydrocarbon group has a cyclic structure) may be carbonyl carbons (-CO-). Examples of the hydrocarbon group include a group having a norbornyl group which may have substituents. The carbon atoms in the norbornyl group may also be carbonyl carbons.

[0112] The anion represented by formula (d1-2) is preferably different from the anions represented by formulas (AN1) to (AN3) described above. For example, Z ２ｃ A group other than an aryl group is preferred. Also, Z ２ｃ In, -SO ３ － For Z, the atoms at the α and β positions are preferably atoms other than carbon atoms that have a fluorine atom as a substituent. ２ｃ is, -SO ３ －In relation to this, the atom at the α position and / or the atom at the β position are preferably ring member atoms in the cyclic group.

[0113] 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, arylene group, or carbonyl group, and Rf represents a hydrocarbon group. Examples of anions represented by formula (d1-3) include those described in

[0040] to

[0046] of Japanese Patent Publication No. 2019-211751,

[0039] to

[0047] of Japanese Patent Publication No. 2021-128331,

[0043] to

[0060] of Japanese Patent Publication No. 2021-165824, and

[0062] and

[0075] of International Publication No. 2023 / 119910, the above descriptions are incorporated herein by reference.

[0114] In formula (d1-4), R ５３ and R ５４ Each of these independently represents an organic group (preferably a hydrocarbon group having a fluorine atom). ５３ and R ５４ They may be joined to each other to form a ring.

[0115] Furthermore, anion represented by the following formula (b-1) can also be considered a non-nucleophilic anion.

[0116] In the formula, Ar ｂ１ This represents a monovalent aromatic ring group which may have substituents.

[0117] In formula (b-1), Ar ｂ１represents a monovalent aromatic ring group which may have substituents. The aromatic ring group may be monocyclic or polycyclic, with monocyclic being preferred. The aromatic ring group may be either an aromatic hydrocarbon group or an aromatic heterocyclic group, with aromatic hydrocarbon being preferred. Examples of the aromatic hydrocarbon group include groups containing aromatic hydrocarbon rings having 6 to 18 carbon atoms, such as benzene, naphthalene, anthracene, and naphthacene. The aromatic heterocyclic group preferably contains at least one heteroatom selected from nitrogen, oxygen, and sulfur atoms as a ring member atom. Examples of aromatic heterocyclic groups include groups containing aromatic heterocyclic rings having 4 to 20 ring member atoms, such as thiophene, furan, pyridine, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole.

[0118] Ar ａ１ Examples of substituents that the monovalent aromatic ring group represented by (b-1) may have include the substituent T described above. Examples include alkyl groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), cycloalkyl groups (e.g., 3 to 15 carbon atoms, preferably 3 to 6 carbon atoms), aromatic ring groups (e.g., 3 to 12 carbon atoms), alkoxy groups (e.g., 1 to 15 carbon atoms, preferably 1 to 6 carbon atoms), and aryloxy groups (e.g., 6 to 14 carbon atoms). The groups exemplified above as substituents may have further substituents if possible. The lower limit of the molecular weight of the organic anion represented by formula (b-1) is preferably 250 or more, and more preferably 300 or more in terms of superior effects of the present invention. The upper limit is preferably 2000 or less, more preferably 1500 or less, and even more preferably 1000 or less.

[0119] The molecular weight of the specific sulfonium salt A is not particularly limited, but is preferably 100 to 3000, more preferably 150 to 2500, and even more preferably 200 to 2000.

[0120] (Anions that can constitute specific sulfonium salt compound B) The anions that can constitute specific sulfonium salt compound B may be monovalent or polyvalent (2 or more) anions, but monovalent anions are preferred. The anions that can constitute specific sulfonium salt compound B may be inorganic or organic anions, but organic anions are preferred. An example of an organic anion that can constitute specific sulfonium salt compound B is the anion represented by formulas (d1-1) to (d1-4) described above as an organic anion that can constitute specific sulfonium salt compound A, and among these, it is preferable that the compound contains an anion part represented by any of the following formulas (BB-1) to (BB-7).

[0121]

[0122] Specific examples of the above-mentioned organic anions include, for example, the organic anions contained in the compounds described in paragraphs

[0305] to

[0314] of International Publication No. 2020 / 158337, which are incorporated herein by reference.

[0123] As the above organic anion, the anion represented by the following formula (a-1) is preferred.

[0124]

[0125] In the formula, Ar ａ１ Ar represents a monovalent aromatic ring group which may have substituents, or an aliphatic hydrocarbon group which may have substituents. ａ１ The monovalent aromatic ring group represented by is Ar in formula (b-1) above. ｂ１ This is the same as the monovalent aromatic ring group represented by , and the preferred embodiment is also the same.

[0126] Ar ａ１ The monovalent aliphatic hydrocarbon group represented by is preferably a linear or branched alkyl group (for example, having 1 to 30 carbon atoms, preferably 1 to 12 carbon atoms) or a cycloalkyl group (for example, having 3 to 30 carbon atoms, preferably 3 to 10 carbon atoms).

[0127] Ar ａ１ A monovalent aromatic ring group and Ar represented by ａ１Examples of substituents that the monovalent aliphatic hydrocarbon group represented by may have include the substituent T mentioned above, which includes hydroxyl groups, amino groups, cyano groups, alkoxy groups (preferably having 1 to 15 carbon atoms), alkyl groups (preferably having 1 to 10 carbon atoms), cycloalkyl groups (preferably having 3 to 15 carbon atoms), aryl groups (preferably having 6 to 14 carbon atoms), alkoxycarbonyl groups (preferably having 2 to 7 carbon atoms), acyl groups (preferably having 2 to 12 carbon atoms), alkoxycarbonyloxy groups (preferably having 2 to 7 carbon atoms), and alkylthio groups (preferably having 1 to 15 carbon atoms).

[0128] The molecular weight of the specific sulfonium salt B is not particularly limited, but is preferably 100 to 3000, more preferably 150 to 2500, and even more preferably 200 to 2000.

[0129] [Various Components of the Resist Composition] <<Resin>> The resist composition contains a resin. The resin is preferably one whose polarity changes due to the action of an acid (hereinafter also referred to as "acid-degradable resin"). The acid-degradable resin is preferably one whose polarity increases due to the action of an acid, thereby increasing its solubility in an alkaline developer. It is also preferable that the acid-degradable resin's polarity increases due to the action of an acid, thereby decreasing its solubility in an organic solvent. The acid-degradable resin is preferably one that has a group that decomposes and changes polarity due to the action of an acid (hereinafter also referred to as "acid-degradable group"), and more preferably one that has a repeating unit having an acid-degradable group.

[0130] <Repeating Unit Having an Acid-Decomposing Group> <Acid-Decomposing Group> The acid-decomposing group may be either a group that decomposes upon the action of an acid, increasing its polarity or decreasing it, but it is preferable that it is a group that decomposes upon the action of an acid, increasing its polarity, and typically it is a group that decomposes upon the action of an acid to produce a polar group. The acid-decomposing group preferably has a structure in which the polar group is protected by a group that is left behind upon the action of an acid (leaving group). Examples of the polar groups mentioned above include acidic groups such as carboxyl groups, phenolic hydroxyl groups, fluorinated alcohol groups, sulfonic acid groups, phosphoric acid groups, sulfonamide groups, sulfonylimide groups, (alkylsulfonyl)(alkylcarbonyl)methylene groups, (alkylsulfonyl)(alkylcarbonyl)imide groups, bis(alkylcarbonyl)methylene groups, bis(alkylcarbonyl)imide groups, bis(alkylsulfonyl)methylene groups, bis(alkylsulfonyl)imide groups, tris(alkylcarbonyl)methylene groups, and tris(alkylsulfonyl)methylene groups, as well as alcoholic hydroxyl groups. Among these, carboxyl groups, phenolic hydroxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), or sulfonic acid groups are preferred as polar groups.

[0131] Examples of groups that are eliminated by the action of an acid include the group represented by any of the following formulas: (Y1), (Y2), and (Y3). Formula (Y1): -C(Rx １ ) (Rx ２ ) (Rx ３ ) Formula (Y2): -C(R ３６ ) (Caution ３７ ) ( OR ３８ ) Formula (Y3): -C(Rn)(H)(Ar)

[0132] In formula (Y1), Rx １ ~Rx ３ Each of these independently represents an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), an alkynyl group, or an aryl group (monocyclic or polycyclic). １ ~Rx ３ If all of them are alkyl groups (linear or branched), then Rx １ ~Rx３ Preferably, at least two of them are methyl groups. Among them, Rx １ ~Rx ３ Each preferably independently represents a linear or branched alkyl group, and Rx １ ~Rx ３ It is more preferable that each of these independently represents a linear alkyl group. １ ~Rx ３ These two may combine to form a monocycle or polycycle. Rx １ ~Rx ３ Preferred alkyl groups include C1-C5 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups. １ ~Rx ３ Preferred cycloalkyl groups include monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, and polycyclic cycloalkyl groups such as norbornyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups. １ ~Rx ３ A vinyl group is preferred as the alkenyl group. Rx １ ~Rx ３ The alkynyl group is preferably an ethynyl group or a propargyl group. Rx １ ~Rx ３ The aryl group is preferably an aryl group having 6 to 10 carbon atoms, such as a phenyl group, a naphthyl group, and an anthyl group.

[0133] Rx １ ~Rx ３ A cycloalkyl group is preferred as the ring formed by the bonding of these two. Rx １ ~Rx ３ The cycloalkyl group formed by the bonding of these 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, with a monocyclic cycloalkyl group having 5 to 6 carbon atoms being more preferred. １ ~Rx３ The cycloalkyl group formed by the bonding of these two groups may have one of the methylene groups constituting the ring replaced by 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 by vinylene groups. The group represented by formula (Y1) is, for example, Rx １ is a methyl group or an ethyl group, and Rx ２ and Rx ３ A preferred embodiment is one in which the two are bonded together to form the aforementioned cycloalkyl group.

[0134] When the resist composition of the present invention is used as an EUV resist, Rx １ ~Rx ３ Alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, and Rx are represented by １ ~Rx ３ The ring formed by the bonding of these two elements may further preferably have a fluorine atom or an iodine atom as a substituent.

[0135] In formula (Y2), R ３６ ~R ３８ Each of these independently represents a hydrogen atom or a monovalent organic group. ３７ and R ３８ These may bond to each other to form a ring. Examples of monovalent organic groups include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, alkenyl groups, and alkynyl groups. ３６ It is also preferable that it be a hydrogen atom. Furthermore, the alkyl group, cycloalkyl group, aryl group, alkenyl group, and alkynyl group may include groups containing heteroatoms such as oxygen atoms and / or carbonyl groups. For example, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, one or more methylene groups may be replaced with groups containing heteroatoms such as oxygen atoms and / or carbonyl groups. ３８ R may bond with other substituents on the repeating main chain to form a ring. ３８The group formed by the bonding of the repeating unit main chain with another substituent is preferably an alkylene group such as a methylene group. When the resist composition of the present invention is used as an EUV resist, R ３６ ~R ３８ A monovalent organic group represented by, and R ３７ and R ３８ The ring formed by the bonding of these elements may further preferably have a fluorine atom or an iodine atom as a substituent.

[0136] In formula (Y3), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may bond to each other to form a non-aromatic ring. An aryl group is preferred as Ar. When the resist composition of the present invention is used as an EUV resist, it is also preferable that the aromatic ring group represented by Ar, and the alkyl group, cycloalkyl group, and aryl group represented by Rn, have a fluorine atom or an iodine atom as a substituent.

[0137] From the standpoint of excellent acid decomposition properties of repeating units, in a leaving group that protects a polar group, if a non-aromatic ring is directly bonded to the polar group (or its residue), it is preferable that the ring member atoms in the non-aromatic ring adjacent to the ring member atom directly bonded to the polar group (or its residue) do not have halogen atoms such as fluorine atoms as substituents.

[0138] Other groups that may be removed by the action of an acid include a 2-cyclopentenyl group having a substituent (such as an alkyl group), such as a 3-methyl-2-cyclopentenyl group, and a cyclohexyl group having a substituent (such as an alkyl group), such as a 1,1,4,4-tetramethylcyclohexyl group.

[0139] As a repeating unit having an acid-degradable group, the repeating unit represented by formula (B1) is preferred.

[0140]

[0141] In formula (B1), R ｂ１ and R ｂ２ Each of these independently represents a hydrogen atom or an alkyl group which may have a substituent. ｂ１Ar represents a single bond or a -COO- bond. ｂ１ This represents an s+t+1 valent aromatic ring group. ｂ１ is, -OR ｂ or -COOR ｂ Represents R ｂ R represents a leaving group. ｂ３ is, -OR ｂ and -COOR ｂ Represents a substituent different from the given one. s represents an integer greater than or equal to 1. t represents an integer greater than or equal to 0. R ｂ１ and Ar ｂ１ They may be bonded to each other via single bonds or divalent linking groups to form a ring, R ｂ and R ｂ３ They may be bonded to each other via single bonds or divalent linking groups to form a ring, R ｂ３ They may be bonded to each other via single bonds or divalent linking groups to form a ring, R ｂ These elements may be linked to each other via single bonds or divalent linking groups to form a ring.

[0142] In formula (B1), R ｂ１ and R ｂ２ Each of these independently represents a hydrogen atom or an alkyl group which may have substituents. ｂ１ and R ｂ２ Examples of alkyl groups that may have the above substituents represented by include a methyl group or -CH ２ -R １１ The group represented by R is an example. １１ R represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. １１ Examples of monovalent organic groups represented by include alkyl groups having 5 or fewer carbon atoms that may be substituted with halogen atoms, acyl groups having 5 or fewer carbon atoms that may be substituted with halogen atoms, and alkoxy groups having 5 or fewer carbon atoms that may be substituted with halogen atoms, with alkyl groups having 3 or fewer carbon atoms being preferred, and methyl groups being more preferred. ｂ１ A hydrogen atom is preferred as the component. ｂ２ Preferably, the group is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0143] In formula (B1), Ar ｂ１ represents an s+t+1 valent aromatic ring group. The above aromatic ring group may be monocyclic or polycyclic. The above aromatic ring group may be either an aromatic hydrocarbon group or an aromatic heterocyclic group, with aromatic hydrocarbon groups being preferred. As the above aromatic hydrocarbon group, groups containing aromatic hydrocarbon rings having 6 to 18 carbon atoms, such as benzene, naphthalene, anthracene, and naphthacene, are preferred. As the heteroatoms of the above aromatic heterocyclic group, nitrogen atoms, oxygen atoms, or sulfur atoms are preferred. As the aromatic heterocyclic group, groups containing aromatic heterocyclic rings with 4 to 20 ring member atoms, such as thiophene, furan, pyridine, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole, are preferred. The number of ring member atoms of the above aromatic ring group is preferably 6 to 18, and more preferably 6 to 10.

[0144] In formula (B1), Y ｂ１ is, -OR ｂ or -COOR ｂ Represents R ｂ R represents a leaving group. ｂ The definition and preferred embodiment of the leaving group represented by are as described above, and the group represented by formulas (Y1) to (Y3) is preferred. When s is an integer of 2 or more, there are multiple Y ｂ１ They may be the same or different from one another.

[0145] In formula (B1), R ｂ３ is, -OR ｂ and -COOR ｂ Represents a different substituent. ｂ３ It is also preferable that the group does not contain an acid-degradable group. ｂ３ Examples of groups represented by include halogen atoms, alkyl groups, cycloalkyl groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, aryl groups, heteroaryl groups, ester groups, carboxyl groups, and groups formed by combining two or more of these. When t is an integer of 2 or more, there are multiple R groups. ｂ３ They may be identical or different to each other.

[0146] In formula (B1), s represents an integer of 1 or more, preferably an integer between 1 and 4, and more preferably 1 or 2. t represents an integer of 0 or more, preferably an integer between 0 and 4, and more preferably an integer between 0 and 2.

[0147] In formula (B1), R ｂ１ and Ar ｂ１ They may be linked to each other via single bonds or divalent linking groups to form a ring. When t represents an integer of 1 or more, R ｂ and R ｂ３ They may be linked to each other via single bonds or divalent linking groups to form a ring. When s represents an integer of 2 or more, R ｂ They may be linked to each other via single bonds or divalent linking groups to form a ring, and when t represents an integer of 2 or more, R ｂ３ These elements may be bonded to each other via single bonds or divalent linking groups to form a ring. Examples of the divalent linking groups include -O-, -S-, -CO-, and -CO ２ -, -SO-, -SO ２ - Examples include 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 substituents.

[0148] As a repeating unit having an acid-degradable group, the repeating unit represented by formula (A) is also preferred.

[0149]

[0150] L １ R represents a divalent linking group which may have a fluorine atom or an iodine atom. １ R 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. ２ This represents a leaving group that is removed by the action of an acid and may have a fluorine atom or an iodine atom. However, L １ , R １ and R ２ At least one of them has a fluorine atom or an iodine atom.１ Divalent linking groups that may have a fluorine atom or an iodine atom, represented by -CO-, -O-, -S-, -SO-, -SO ２ - Hydrocarbon groups which may have a fluorine atom or an iodine atom (for example, alkylene groups, cycloalkylene groups, alkenylene groups, and arylene groups, etc.), and linked groups formed by linking multiple thereof. Among these, L １ The alkylene group is preferably -CO-, an arylene group, or an -arylene group-an alkylene group having a fluorine or iodine atom, and more preferably -CO-, or an -arylene group-an alkylene group having a fluorine or iodine atom. The arylene group is preferably a phenylene group. 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 and iodine atoms in the alkylene group having a fluorine or iodine atom is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0151] R １ The alkyl group represented by may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but 1 to 10 is preferred, and 1 to 3 is more preferred. 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 R, 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 may contain heteroatoms other than halogen atoms, such as oxygen atoms.

[0152] R ２ Examples of leaving groups that may have a fluorine atom or an iodine atom, represented by formula (Y1), formula (Y2), and formula (Y3) above, include leaving groups that have a fluorine atom or an iodine atom.

[0153] As a repeating unit having an acid-degradable group, a repeating unit represented by formula (AI) is also preferred.

[0154]

[0155] In equation (AI), Xa １ Rx represents a hydrogen atom or an optionally substituted alkyl group. T represents a single bond or a divalent linking group. １ ~Rx ３ The definition and preferred embodiment of Rx in formula (Y1) １ ~Rx ３ They are the same.

[0156] Xa １ Examples of alkyl groups that may have substituents, represented by , include a methyl group or -CH ２ -R １１ The group represented by R is an example. １１ R represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. １１ Examples of monovalent organic groups represented by include alkyl groups having 5 or fewer carbon atoms that may be substituted with halogen atoms, acyl groups having 5 or fewer carbon atoms that may be substituted with halogen atoms, and alkoxy groups having 5 or fewer carbon atoms that may be substituted with halogen atoms, with alkyl groups having 3 or fewer carbon atoms being preferred and methyl groups being more preferred. １ Preferably, the group is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0157] Examples of divalent linking groups for T include alkylene groups, aromatic ring groups, -COO-Rt- groups, and -O-Rt- groups. 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 -CH ２ -, - (CH ２ ) ２ - or - (CH ２ ) ３ - is preferable.

[0158] When each of the above groups has substituents, examples of substituents include alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, and alkoxycarbonyl groups (2 to 6 carbon atoms). The number of carbon atoms of the substituent is preferably 8 or less.

[0159] The repeating unit represented by formula (AI) is an acid-degradable (meth)acrylate tertiary alkyl ester repeating unit (Xa １ A repeating unit in which represents a hydrogen atom or a methyl group, and T represents a single bond, is preferred.

[0160] The repeating unit having an acid-degradable group may have an acid-degradable group containing an unsaturated bond. The repeating unit represented by formula (B) is preferred as the repeating unit having an acid-degradable group containing an unsaturated bond.

[0161]

[0162] In formula (B), Xb represents a hydrogen atom, a halogen atom, or an optionally substituted alkyl group. L represents a single bond or an optionally substituted divalent linking group. １ ~Ry ３ Each of these 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. However, Ry １ ~Ry ３ At least one of these represents an alkenyl group, an alkynyl group, a monocyclic or polycyclic cycloalkenyl group, or a monocyclic or polycyclic aryl group. １ ~Ry ３ These two may combine to form a monocyclic or polycyclic (monocyclic or polycyclic cycloalkyl group, cycloalkenyl group, etc.) structure.

[0163] In formula (B), the optionally substituted alkyl group represented by Xb is, for example, a methyl group or -CH ２ -R １１ The group represented by R is an example. １１Xa is as described above. For Xb, a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group is preferred.

[0164] In formula (B), the divalent linking group represented by L includes -Rt-, -CO-, -COO-Rt-, -COO-Rt-CO-, -Rt-CO-, and -O-Rt-. Rt represents an alkylene group, a cycloalkylene group, or an aromatic ring group, with an aromatic ring group being preferred. Rt may have substituents such as a halogen atom, a hydroxyl group, or an alkoxy group. As for L, -Rt-, -CO-, -COO-Rt-CO-, or -Rt-CO- are preferred.

[0165] In formula (B), Ry １ ~Ry ３ The alkyl group represented is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, or t-butyl group. １ ~Ry ３ The cycloalkyl group represented by is preferably a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. １ ~Ry ３ A vinyl group is preferred as the alkenyl group represented by Ry. １ ~Ry ３ As the alkynyl group represented by , an ethynyl group is preferred. １ ~Ry ３ The cycloalkenyl group represented by is preferably a cyclopentyl group and a monocyclic cycloalkyl group such as a cyclohexyl group that contains a double bond in part. １ ~Ry ３ The aryl group represented by is preferably an aryl group having 6 to 10 carbon atoms, such as a phenyl group, a naphthyl group, and an anthyl group.

[0166] Ry １ ~Ry ３The cycloalkyl group formed by the bonding of these two groups is preferably a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Among these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferred. １ ~Ry ３ A cycloalkyl group or cycloalkenyl group formed by the bonding of these two elements may, for example, have one of the methylene groups constituting the ring be a heteroatom such as an oxygen atom, a carbonyl group, or -SO ２ -Base and -SO ３ - These groups may be replaced by groups containing heteroatoms such as - groups, vinylidene groups, or combinations thereof. Furthermore, in these cycloalkyl or cycloalkenyl groups, one or more ethylene groups constituting the cycloalkane or cycloalkene ring may be replaced by vinylene groups. The repeating unit represented by formula (B) is, for example, Ry １ is a methyl group, ethyl group, vinyl group, allyl group, or aryl group, R ２ and Ry ３ A preferred embodiment is one in which the two are bonded together to form the aforementioned cycloalkyl group or cycloalkenyl group.

[0167] When each of the above groups has substituents, examples of substituents include alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, and alkoxycarbonyl groups (2 to 6 carbon atoms). The number of carbon atoms of the substituent is preferably 8 or less.

[0168] The repeating units represented by formula (B) are preferably acid-degradable (meth)acrylic acid tertiary ester repeating units (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a -CO- group), acid-degradable hydroxystyrene tertiary alkyl ether repeating units (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a phenyl group), or acid-degradable styrene carboxylic acid tertiary ester repeating units (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)).

[0169] Specific examples of repeating units having an acid-degradable group containing an unsaturated bond include, for example, the repeating units described in

[0067] to

[0071] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0170] Specific examples of repeating units having acid-degradable groups are shown below, but are not limited to these. Repeating units having acid-degradable groups described in the examples later are also preferred. Furthermore, for repeating units having acid-degradable groups, one can refer to, for example, the descriptions in

[0029] to

[0071] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0171]

[0172] The repeating unit having an acid-degradable group preferably includes at least one repeating unit selected from the group consisting of the repeating unit represented by formula (B1) and the repeating unit represented by formula (AI) described above, and more preferably includes the repeating unit represented by formula (B1) described above.

[0173] The repeating units having acid-degradable groups may be used individually or in combination of two or more types. The content of the repeating units having acid-degradable groups is preferably 5 to 100 mol%, more preferably 10 to 80 mol%, and even more preferably 15 to 70 mol%, relative to the total repeating units in the acid-degradable resin.

[0174] <Repeating units having acidic groups> The resin preferably contains repeating units having acidic groups. The repeating units having acidic groups are preferably different from the repeating units having acid-degradable groups. The repeating units having acidic groups may also have fluorine atoms or iodine atoms. Preferred acidic groups are carboxyl groups, phenolic hydroxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), sulfonic acid groups, sulfonamide groups, or isopropanol groups, with phenolic hydroxyl groups being more preferred. In other words, the resin preferably contains repeating units having phenolic hydroxyl groups (phenolic hydroxyl groups). The hexafluoroisopropanol group may have one or more fluorine atoms (preferably one to two) substituted with groups other than fluorine atoms (such as alkoxycarbonyl groups). As for the acidic groups, the -C(CF) formed in this way is preferred. ３ ) (OH)-CF ２ - is also preferable. In addition, one or more fluorine atoms are substituted with a group other than a fluorine atom, -C(CF ３ ) (OH)-CF ２ A ring containing - may be formed.

[0175] As the repeating unit having an acid group, the repeating unit represented by the following formula (Pa1) is preferred; that is, the resin preferably contains the repeating unit represented by the following formula (Pa1).

[0176]

[0177] In formula (Pa1), R ａ１ and R ａ２ Each of these independently represents a hydrogen atom or a substituent. ａ１ Ar represents a single bond or a divalent linking group. ａ１ Ar represents an aromatic ring group with (m+n+1) valency. ａ１ And, R ａ２ or L ａ１ This may be a single bond or a bond via a linking group. Ｘ represents a substituent other than a hydroxyl group. n represents an integer between 1 and 9 (inclusive). m represents an integer between 0 and 8 (inclusive).

[0178] In the above formula (Pa1), R ａ１ and R ａ２ Each of these independently represents a hydrogen atom or a substituent. ａ１ and R ａ２ The substituent represented 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 linear or branched, and may have substituents. 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 even more preferably 1 to 3. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups. 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 substituents. ａ１ and R ａ２ Examples of halogen atoms represented by include fluorine, chlorine, bromine, and iodine atoms, with fluorine or iodine atoms being preferred. ａ１ and R ａ２ The alkyl group contained in the alkoxycarbonyl group represented by may be linear or branched. The number of carbon atoms in the alkyl group contained in the alkoxycarbonyl group is not particularly limited, but 1 to 5 is preferred, and 1 to 3 is more preferred. The alkoxycarbonyl group may have substituents.

[0179] In the above formula (Pa1), L ａ１ L represents a single bond or a divalent linking group. ａ１ Examples of divalent linking groups represented by include -COO- and -CONR ａ３ -, alkylene groups, or groups formed by combining two or more of these groups.ａ３ R represents a hydrogen atom or an alkyl group. Preferred alkylene groups include C1-C8 alkylene groups such as methylene, ethylene, propylene, butylene, hexylene, and octylene. The alkylene group may have substituents. ａ３ Examples of alkyl groups that represent an alkyl group include alkyl groups having 20 or fewer carbon atoms, such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, hexyl group, 2-ethylhexyl group, octyl group, and dodecyl group, with alkyl groups having 8 or fewer carbon atoms being preferred.

[0180] In the above formula (Pa1), Ar ａ１ Ar represents an aromatic ring group with (m+n+1) valency. ａ１ The aromatic ring group represented by may be either an aromatic hydrocarbon group or an aromatic heterocyclic group. Preferred aromatic hydrocarbon groups include groups containing aromatic hydrocarbons having 6 to 18 carbon atoms, such as benzene, naphthalene, anthracene, and naphthacene. Preferred aromatic heterocyclic groups include groups containing aromatic heterocyclic rings with 4 to 20 ring member atoms, such as thiophene, furan, pyridine, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole.

[0181] Ar ａ１ And, R ａ２ or L ａ１ These may be bonded via single bonds or linking groups. Examples of linking groups include -O-, -S-, -CO-, and -CO ２ -, -SO-, -SO ２ - Examples include 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 substituents.

[0182] In the above formula (Pa1), R Ｘ R represents substituents other than hydroxyl groups. ＸExamples of substituents represented by include carboxyl groups, sulfo groups, cyano groups, halogen atoms, hydrocarbon groups, amino groups, nitro groups, and groups formed by combining two or more of these. Ｘ Examples of hydrocarbon groups represented by include alkyl groups (preferably having 1 to 10 carbon atoms), cycloalkyl groups (preferably having 5 to 15 carbon atoms), and alkenyl groups (preferably having 2 to 10 carbon atoms). Ｘ The hydrocarbon group represented by may have substituents. Also, R Ｘ The hydrocarbon group represented is -CH ２ If it contains -, -CH ２ At least one of the following is -O-, -CO-, -S-, and -SO ２ - May be replaced by at least one selected from the group consisting of -. Ｘ The substituent represented by preferably has a halogen atom. The halogen atom is preferably a fluorine atom or an iodine atom.

[0183] In the above formula (Pa1), n ​​represents an integer between 1 and 9, preferably between 1 and 5, and more preferably between 1 and 4. m represents an integer between 0 and 8, preferably between 0 and 4, and more preferably between 0 and 3.

[0184] The repeating unit having an acid group is preferably a repeating unit represented by the following formula (Pa2), that is, the resin preferably contains a repeating unit represented by the following formula (Pa2).

[0185]

[0186] In formula (Pa2), R ａ４ L represents a hydrogen atom or an alkyl group. ａ２ represents a single join or -COO-. r represents an integer between 0 and 3 (inclusive). Ｘ１ represents a halogen atom or hydrocarbon group. n1 represents an integer between 1 and 5. m1 represents an integer between 0 and 4.

[0187] In the above formula (Pa2), R ａ４ R represents a hydrogen atom or an alkyl group.ａ４ The alkyl group represented by may be linear or branched and may have substituents. 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 alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups.

[0188] In the above formula (Pa2), L ａ２ represents a single bond or -COO-, with a single bond being preferred. r represents an integer between 0 and 3, preferably between 0 and 2, more preferably 0 or 1, and even more preferably 0. In formula (Pa2), the aromatic ring is benzene when r is 0, naphthalene when r is 1, anthracene when r is 2, and naphthacene when r is 3. n1 represents an integer between 1 and 5, preferably between 1 and 4. m1 represents an integer between 0 and 4, preferably between 0 and 3.

[0189] In the above formula (Pa2), R Ｘ１ R represents a halogen atom or hydrocarbon group. Ｘ１ The halogen atom represented is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and more preferably a fluorine atom or an iodine atom. Ｘ１ Examples of hydrocarbon groups represented by include alkyl groups (preferably having 1 to 10 carbon atoms), cycloalkyl groups (preferably having 5 to 15 carbon atoms), and alkenyl groups (preferably having 2 to 10 carbon atoms). Ｘ１ The hydrocarbon group represented by may have substituents. Also, R Ｘ１ The hydrocarbon group represented is -CH ２ If it contains -, -CH ２ At least one of the following is -O-, -CO-, -S-, and -SO ２ - May be replaced by at least one selected from the group consisting of -. Ｘ１ The hydrocarbon group represented by preferably has a halogen atom. The halogen atom is preferably a fluorine atom or an iodine atom.

[0190] Specific examples of repeating units having an acid group include, for example, the repeating units described in

[0079] to

[0110] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0191] The repeating units having acidic groups may be used alone or in combination of two or more types. The content of repeating units having acidic groups is preferably 5 to 90 mol%, more preferably 10 to 90 mol%, and even more preferably 20 to 80 mol%, relative to the total repeating units of the resin.

[0192] <Other Repeating Units> The resin may contain other repeating units other than those described above. The content of other repeating units is preferably 0 to 50 mol%, and more preferably 0 to 30 mol%, relative to the total repeating units of the resin.

[0193] 《Repeating units that do not have either an acid-degradable group or an acid group, but have a fluorine atom, a bromine atom, or an iodine atom》 The resin may have repeating units (hereinafter also simply referred to as "repeating unit X") that do not have either an acid-degradable group or an acid group, but have a fluorine atom, a bromine atom, or an iodine atom. It is preferable that repeating unit X is different from repeating unit Y and repeating unit P, which will be described later. The repeating unit X is preferably a repeating unit represented by formula (C).

[0194]

[0195] In formula (C), L ５ R represents a single bond or an ester group. ９ R represents an alkyl group which may have a hydrogen atom, or a fluorine atom or an iodine atom. １０ This represents an alkyl group which may have a hydrogen atom, 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 which is a combination thereof.

[0196] The content of repeating unit X is preferably 0 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, relative to the total repeating units in the resin. Furthermore, the upper limit is preferably less than 40 mol%, and more preferably 35 mol% or less, relative to the total repeating units in the resin.

[0197] Furthermore, the resin may have repeating units having at least one of a fluorine atom, a bromine atom, and an iodine atom. 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 having an acid-degradable group, repeating units having a fluorine atom, a bromine atom, or an iodine atom and having an acidic group, and repeating units having a fluorine atom, a bromine atom, or an iodine atom. The total content of repeating units having at least one of a fluorine atom, a bromine atom, and an iodine atom among the repeating units of the resin 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, relative to the total repeating units of the resin. There is no particular upper limit, but for example, it is 100 mol% or less relative to the total repeating units of the resin.

[0198] Specific examples of repeating units having fluorine atoms or iodine atoms include, for example, the repeating units described in

[0116] to

[0117] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0199] Repeating units having lactone groups, sultone groups, or carbonate groups The resin may have repeating units (hereinafter also simply referred to as "repeating unit Y") having at least one selected from the group consisting of lactone groups, sultone groups, and carbonate groups. It is also preferable that repeating unit Y does not have acidic groups such as hydroxyl groups and hexafluoropropanol groups.

[0200] The lactone group or sultone group may have a lactone structure or a sultone structure. The lactone structure or sultone structure is preferably a 5-7 membered ring lactone structure or a 5-7 membered ring sultone structure. More preferably, the 5-7 membered ring lactone structure is fused with another ring structure in the form of a bicyclo or spiro structure, or the 5-7 membered ring sultone structure is fused with another ring structure in the form of a bicyclo or spiro structure. For units containing a lactone group or sultone group, refer to, for example, the descriptions in International Publication No. 2022 / 024928

[0119] to

[0126] and

[0132] to

[0133] , which are incorporated herein by reference.

[0201] A cyclic carbonate ester group is preferred as the carbonate group. For repeating units having a cyclic carbonate ester group, see, for example, the descriptions in

[0127] to

[0133] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0202] When the resin contains repeating units Y, the content of repeating units Y is preferably 1 mol% or more, and more preferably 10 mol% or more, relative to the total repeating units in the resin. Furthermore, the upper limit is preferably less than 40 mol%, and more preferably 35 mol% or less, relative to the total repeating units in the resin.

[0203] <Repeating units having photoacid-generating groups> The resin may contain repeating units (hereinafter simply referred to as "repeating units P") that have groups that generate acid upon irradiation with active light or radiation (also called "photoacid-generating groups"), but it is also preferable that the resin does not contain repeating units P. An example of repeating units P is the repeating unit represented by formula (4).

[0204]

[0205] In formula (4), R ４１ L represents a hydrogen atom or a methyl group. ４１ L represents a single bond or a divalent linking group. ４２ R represents a divalent linking group. ４０ This represents a structural site that decomposes upon irradiation with active light or radiation, generating acid in the side chain.

[0206] In formula (4), L ４１ represents a single bond or a divalent linking group, and a single bond or -COO- is preferred. ４２ The symbols represent divalent linking groups, including alkylene groups, cycloalkylene groups, arylene groups, -O-, -CO-, -S-, -SO-, and -SO ２ A linking group consisting of at least one selected from the group consisting of - and -NR- is preferred. R represents a hydrogen atom or an organic group (preferably an organic group having 1 to 10 carbon atoms, such as an alkyl group, cycloalkyl group, or aryl group). The alkylene group may be linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but 1 to 10 is preferred. The cycloalkylene group may be monocyclic or polycyclic. The number of carbon atoms in the cycloalkylene group is not particularly limited, but 3 to 20 is preferred, and 5 to 15 is more preferred. The number of carbon atoms in the arylene group is not particularly limited, but 6 to 20 is preferred, and 6 to 10 is more preferred. The alkylene group, cycloalkylene group and arylene group may have substituents, and the substituent T mentioned above is an example of a substituent.

[0207] In formula (4), R ４０ The group is preferably represented by the following formula (S4-1).

[0208]

[0209] In equation (S4-1), Q － represents an acid residue, M ＋ * represents a cation. * represents L ４１ This indicates the bonding position. An acid residue is a group formed when a proton dissociates from an acid. Q － is a carboxylate anion group (COO － ), sulfonate anion group (SO ３ － ), or sulfonamide group (N － -SO ２ R Ｎ１ It is represented by R Ｎ１represents an organic group, and examples include organic groups having 1 to 10 carbon atoms, with alkyl groups, fluoroalkyl groups, or aryl groups being preferred. A sulfonate anion group is more preferred. ＋ Examples of cations represented by this formula include the specific sulfonium salts mentioned above and cations contained in other photoacid generators described later.

[0210] Specific examples of repeating units P include, for example, the repeating units described in paragraphs

[0094] to

[0105] of Japanese Patent Publication No. 2014-041327, the repeating units described in paragraph

[0094] of International Publication No. 2018 / 193954, and the repeating units described in paragraph

[0138] of International Publication No. 2022 / 024928, and these descriptions are incorporated herein by reference. Furthermore, examples of repeating units represented by formula (4) include, for example, the repeating units described in paragraphs

[0094] to

[0105] of Japanese Patent Publication No. 2014-041327, and the repeating units described in paragraph

[0094] of International Publication No. 2018 / 193954, and these descriptions are incorporated herein by reference.

[0211] When the resin contains repeating units P, the content of repeating units P is preferably 1 mol% or more, more preferably 3 mol% or more, and even more preferably 5 mol% or more, relative to the total repeating units in the resin. Furthermore, the content of repeating units P is preferably less than 40 mol%, more preferably 30 mol% or less, and even more preferably 20 mol% or less, relative to the total repeating units in the resin.

[0212] (Repeating units represented by formula (V-1) or formula (V-2)) The resin may have repeating units represented by the following formula (V-1) or formula (V-2). It is preferable that the repeating units represented by formula (V-1) and the following formula (V-2) are different from the repeating units described above.

[0213]

[0214] In equation (V-1) and equation (V-2) below, R ６ and R ７Each of these 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 fluorinated alkyl group having 1 to 6 carbon atoms), or a carboxyl group. As the alkyl group, linear, branched, or cyclic alkyl groups having 1 to 10 carbon atoms are preferred. ３ n represents an integer between 0 and 6. ４ X represents an integer between 0 and 4. ４ represents a methylene group, an oxygen atom, or a sulfur atom. Examples of repeating units represented by formula (V-1) or (V-2) include the repeating units described in paragraph

[0100] of International Publication No. 2018 / 193954, which are incorporated herein by reference.

[0215] 《Repeating units to reduce the mobility of the main chain》 A resin is preferable to have a high glass transition temperature (Tg) in order to suppress excessive diffusion of generated acid or pattern breakdown during development. The resin may have repeating units to reduce the mobility of the main chain in order to adjust the glass transition temperature. For repeating units to reduce the mobility of the main chain, refer to the contents of

[0144] to

[0160] of International Publication No. 2022 / 024928.

[0216] Repeating units having at least one group selected from lactone groups, sultone groups, carbonate groups, hydroxyl groups, cyano groups, and alkali-soluble groups. The resin may have repeating units having at least one group selected from lactone groups, sultone groups, carbonate groups, hydroxyl groups, cyano groups, and alkali-soluble groups. Examples of repeating units having lactone groups, sultone groups, or carbonate groups include the repeating units described for repeating unit Y above. The preferred content is also as described for repeating unit Y.

[0217] The resin may have repeating units having a hydroxyl group or a cyano group. This improves substrate adhesion. The repeating units having a hydroxyl group or a cyano group are preferably repeating units having saturated hydrocarbon groups (substituted with a hydroxyl group or a cyano group) that have a hydroxyl group or a cyano group. Alternatively, they may be repeating units having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The repeating units having a hydroxyl group or a cyano group are preferably not having acid-degradable groups. Examples of repeating units having a hydroxyl group or a cyano group include the repeating units described in paragraphs

[0081] to

[0084] of Japanese Patent Application Publication No. 2014-098921, and the above description is incorporated herein by reference.

[0218] The resin may have repeating units having alkali-soluble groups. The inclusion of repeating units having alkali-soluble groups in the resin increases resolution in contact hole applications. Examples of alkali-soluble groups include carboxyl groups, sulfonamide groups, sulfonylimide groups, bissulfonylimide groups, and aliphatic alcohol groups (e.g., hexafluoroisopropanol group) whose α-position is substituted with an electron-withdrawing group, with carboxyl groups being preferred. Examples of repeating units having alkali-soluble groups include the repeating units described in paragraphs

[0085] and

[0086] of Japanese Patent Application Publication No. 2014-098921, which are incorporated herein by reference.

[0219] 《Repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposition》 The resin may have repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposition. This reduces the 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 decomposition include repeating units derived from 1-adamantyl (meth)acrylate, diamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate, or cyclohexyl (meth)acrylate.

[0220] 《Repeating units represented by formula (III) that do not have either a hydroxyl group or a cyano group》 The resin may have repeating units represented by formula (III) that do not have either a hydroxyl group or a cyano group.

[0221]

[0222] In formula (III), R ５ represents a hydrocarbon group having at least one cyclic structure and lacking both a hydroxyl group and a cyano group. Ra represents a hydrogen atom, an alkyl group, or -CH ２ -O-Ra ２ It represents the base. In the formula, Ra ２ represents a hydrogen atom, an alkyl group, or an acyl group. Examples of repeating units represented by formula (III) that do not have either a hydroxyl group or a cyano group include the repeating units described in paragraphs

[0087] to

[0094] of Japanese Patent Application Publication No. 2014-098921, which are incorporated herein by reference.

[0223] Other Repeating Units The resin may have other repeating units other than those described above. For other repeating units, see, for example, the descriptions in

[0141] to

[0143] and

[0169] to

[0170] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0224] In addition to the repeating structural units described above, the resin may have various repeating structural units for the purpose of adjusting dry etching resistance, suitability for standard developers, substrate adhesion, resist profile, resolution, heat resistance, and sensitivity.

[0225] A preferred embodiment of the present invention is that the resin has at least one selected from the group consisting of lactone groups, carbonate groups, sultone groups, and saturated hydrocarbon groups having hydroxyl groups. Having at least one selected from the group consisting of lactone groups, carbonate groups, sultone groups, and saturated hydrocarbon groups having hydroxyl groups further improves etching resistance and LWR performance.

[0226] In a preferred embodiment of the present invention, the resin contains repeating units having iodine atoms. By including repeating units having iodine atoms in the acid-degradable resin, the absorption rate of EUV light and the like is increased, the effects of shot noise can be reduced, and the LWR performance is further improved.

[0227] The resin can be synthesized according to conventional methods (e.g., radical polymerization). According to the GPC method, the weight-average molecular weight (Mw) of the resin, expressed as polystyrene equivalent, is preferably 30,000 or less, more preferably 1,000 to 30,000, even more preferably 3,000 to 30,000, and particularly preferably 3,500 to 15,000. The polydispersity (molecular weight distribution, Mw / Mn) of the resin is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, even more preferably 1.1 to 2.0, and particularly preferably 1.1 to 1.8. A lower polydispersity results in better resolution and resist shape, smoother sidewalls of the resist pattern, and superior roughness.

[0228] The resin content is preferably 30.0 to 99.9% by mass, more preferably 40.0 to 99.9% by mass, and even more preferably 60.0 to 90.0% by mass, based on the total solid content of the resist composition. Only one type of resin may be used, or two or more types may be used. When two or more types are used, it is preferable that their total content is within the above preferred content range.

[0229] <<Photoacid Generator>> The resist composition contains a photoacid generator. Examples of the photoacid generator include the specified sulfonium salt compound A and other photoacid generators other than the specified sulfonium salt compound A. The resist composition preferably contains the specified sulfonium salt compound A as the photoacid generator, as this provides superior effects of the present invention. The photoacid generator is not particularly limited as long as it is a compound that generates acid upon irradiation (exposure) with active light or radiation.

[0230] The following describes other photoacid generators. <Other Photoacid Generators> The upper limit of the pKa of the acid generated by exposure from other photoacid generators is preferably 2.0 or less, more preferably 1.5 or less, even more preferably 1.0 or less, and particularly preferably -0.5 or less. The lower limit of the above pKa is more preferably -5.0 or higher, even more preferably -4.5 or higher, and even more preferably -2.0 or higher.

[0231] Other photoacid generators may be in the form of low molecular weight compounds or incorporated into a part of the resin. Alternatively, both low molecular weight compounds and incorporated into a part of the resin may be used in combination. The photoacid generator is preferably in the form of a low molecular weight compound. If the other photoacid generator is in the form of a low molecular weight compound, its molecular weight is not particularly limited, but is preferably 500 to 3000, more preferably 600 to 2500, and even more preferably 700 to 2000. If the other photoacid generator is incorporated into a part of the resin, it may be incorporated into a part of the acid-degradable resin or into a resin different from the acid-degradable resin.

[0232] Other photoacid generators include, for example, "M ＋ X － Examples of compounds represented by '' (onium salts) include compounds that generate organic acids upon exposure. Examples of organic acids include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, and camphor sulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, and aralkyl carboxylic acids, etc.), carbonylsulfonylimide acid, bis(alkylsulfonyl)imide acid, and tris(alkylsulfonyl)methidic acid.

[0233] "M ＋ X － In the compound represented by ", M ＋ The symbol represents a cation, preferably an organic cation. The valency of the cation may be monovalent or divalent or higher. The cation is preferably a cation represented by formula (ZaI) (hereinafter also referred to as "cation (ZaI)") or a cation represented by formula (ZaII) (hereinafter also referred to as "cation (ZaII)").

[0234]

[0235] In the above formula (ZaI), R ２０１ , R ２０２ , and R ２０３ Each of these independently represents an organic group. ２０１ , R ２０２ , and R ２０３ The number of carbon atoms in the organic group is preferably 1 to 30, and more preferably 1 to 20. ２０１ ~R ２０３ Two of these may bond 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 the bonding of two of these include alkylene groups (e.g., butylene and pentylene groups) and -CH ２ -CH ２ -O-CH ２ -CH ２ - is an example. When the resist composition of the present invention is used as an EUV resist, R ２０１ ~R ２０５ Preferably, the cation contains a fluorine atom or an iodine atom as a substituent. Preferred embodiments of the cation represented by formula (ZaI) include cation (ZaI-1), cation (ZaI-2), cation (ZaI-3b), and cation (ZaI-4b), which will be described later.

[0236] First, let's explain the cation (ZaI-1). The cation (ZaI-1) is R in the above formula (ZaI). ２０１ ~R ２０３ It is an arylsulfonium cation in which at least one of the groups is an aryl group. ２０１ ~R ２０３ All of them may be aryl groups, or R ２０１ ~R ２０３ A portion of it may be an aryl group, and the remainder may be an alkyl group or a cycloalkyl group. ２０１ ~R ２０３ One of them is an aryl group, R ２０１ ~R ２０３The remaining two of these may bond 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 the bonding of two of these 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 Examples of arylsulfonium cations include triarylsulfonium cation, diarylalkylsulfonium cation, diarylcycloalkylsulfonium cation, aryldialkylsulfonium cation, and aryldicycloalkylsulfonium cation.

[0237] The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, with the phenyl group being more preferred. When the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different. The aryl group may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, or a sulfur atom, etc. Examples of heterocyclic structures include pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, and benzothiophene residues. The alkyl or cycloalkyl group that the arylsulfonium cation may have 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, with methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, or cyclohexyl group being more preferred.

[0238] The above aryl group may have substituents, and preferred substituents are alkyl groups (e.g., C1-C15), cycloalkyl groups (e.g., C3-C15), aryl groups (e.g., C6-C14), alkoxy groups (e.g., C1-C15), cycloalkylalkoxy groups (e.g., C1-C15), halogen atoms (e.g., fluorine and iodine), hydroxyl groups, carboxyl groups, ester groups, sulfinyl groups, sulfonyl groups, alkylthio groups, phenylthio groups, or alkyloxycarbonylalkyleneoxy groups. The above substituents may have further substituents if possible, and it is also preferable 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 preferable that the above substituents form an acid-degradable group in any combination. An acid-degradable group is a group that decomposes and increases in polarity upon the action of an acid, and it is preferable that the polar group is protected by a group that is eliminated upon the action of an acid.

[0239] Next, we will explain the cation (ZaI-2). The cation (ZaI-2) is R in formula (ZaI). ２０１ ~R ２０３ However, each of these independently represents a cation that does not have an aromatic ring. The term "aromatic ring" also includes aromatic rings containing heteroatoms. R ２０１ ~R ２０３ The number of carbon atoms in the organic group that does not have an aromatic ring is preferably 1 to 30, and more preferably 1 to 20. ２０１ ~R ２０３ The members are preferably alkyl groups, cycloalkyl groups, allyl groups, or vinyl groups, more preferably linear or branched 2-oxoalkyl groups, 2-oxocycloalkyl groups, or alkoxycarbonylmethyl groups, and even more preferably linear or branched 2-oxoalkyl groups.

[0240] R ２０１ ~R ２０３Examples of alkyl and cycloalkyl groups represented by include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, and pentyl group), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl group, cyclohexyl group, and norbornyl group). ２０１ ~R ２０３ This 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.

[0241] Next, we will explain the cation (ZaI-3b). The cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).

[0242]

[0243] In formula (ZaI-3b), R １ｃ ~R ５ｃ Each of these 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 Each of these independently represents a hydrogen atom, an alkyl group (e.g., a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group. ｘ and R ｙ Each of these 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.

[0244] 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 ｙThese elements 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 above rings include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterorings, and polycyclic fused rings formed by the combination of two or more of these rings. Examples of rings include 3 to 10-membered rings, preferably 4 to 8-membered rings, and more preferably 5 or 6-membered rings.

[0245] R １ｃ ~R ５ｃ Two or more of the following, R ６ｃ and R ７ｃ , and R ｘ and R ｙ Examples of groups formed by the bonding include alkylene groups such as butylene and pentylene groups. The methylene group in the alkylene group may be substituted with a heteroatom such as an oxygen atom. ５ｃ and R ６ｃ , and R ５ｃ and R ｘ The groups formed by the bonding of these elements are preferably single bonds or alkylene groups. Examples of alkylene groups include methylene groups and ethylene groups.

[0246] 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 rings formed by the bonding of these elements to each other may have substituents.

[0247] Next, we will explain the cation (ZaI-4b). The cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).

[0248]

[0249] In equation (ZaI-4b), l represents an integer from 0 to 2, and r represents an integer from 0 to 8. １３ R represents a group containing a hydrogen atom, a halogen atom (e.g., a fluorine atom and an iodine atom), a hydroxyl group, an alkyl group, an alkyl halide, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as part). These groups may have substituents. １４ R represents a hydroxyl group, a halogen atom (e.g., a fluorine atom and an iodine atom), an alkyl group, an alkyl halide, 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 in part). These groups may have substituents. １４ The fields in which multiple instances exist may be independent or distinct from each other. １５ Each of these independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. １５ They may bond to each other to form a ring. Two R １５ When these atoms bond to each other to form a ring, the ring may contain heteroatoms such as oxygen atoms or nitrogen atoms. In one embodiment, two R １５ It is preferable that the alkyl group is an alkylene group and that they bond to each other to form a ring structure. The alkyl group, cycloalkyl group and naphthyl group and the two R １５ The ring formed by the bonding of these elements may have substituents.

[0250] In formula (ZaI-4b), R １３ , R １４ and R １５ The alkyl group may be linear or branched. The alkyl group preferably has 1 to 10 carbon atoms. The alkyl group is preferably a methyl group, ethyl group, n-butyl group, or t-butyl group.

[0251] Next, we will explain equation (ZaII). In equation (ZaII), R ２０４ and R２０５ Each of these independently represents an aryl group, an alkyl group, or a cycloalkyl group. ２０４ and R ２０５ The aryl group is preferably a phenyl group or a naphthyl group, with the phenyl group being more preferred. Alternatively, it may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of heterocycle aryl group skeletons include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. ２０４ and R ２０５ The alkyl and cycloalkyl groups are preferably linear alkyl groups having 1 to 10 carbon atoms, branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, or pentyl group), or cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl group, cyclohexyl group, or norbornyl group).

[0252] R ２０４ and R ２０５ The aryl group, alkyl group, and cycloalkyl group may each independently have substituents. ２０４ and R ２０５ Examples of 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.

[0253] Specific examples of organic cations are shown below, but the present invention is not limited thereto.

[0254]

[0255]

[0256] "M ＋ X － In the compound represented by ", X －The symbol represents an anion, preferably an organic anion. The valency of the anion may be monovalent or divalent or more. Examples of organic anions include those similar to those contained in specific sulfonium salt compound A. Organic anions may be used individually or in combination of two or more.

[0257] The other photoacid generator is preferably at least one selected from the group consisting of compounds (I) to (II).

[0258] (Compound (I)) Compound (I) is a compound having one or more of the following structural sites X and one or more of the following structural sites Y, which generates an acid containing the following first acidic site derived from the following structural site X and the following second acidic site derived from the following structural site Y upon irradiation with active light or radiation. Structural site X: Anionic site A １ － and cation site M １ ＋ It consists of and is irradiated with active light or radiation, HA １ Structural site that forms the first acidic site represented by Structural site Y: Anionic site A ２ － and cation site M ２ ＋ It consists of and is irradiated with active light or radiation, HA ２ The structural site (I) that forms the second acidic site represented by satisfies the following condition I.

[0259] Condition I: In the above compound (I), the above cation site M in the above structural site X. １ ＋ and the cation portion M in the structural portion Y. ２ ＋ to H ＋ The compound PI obtained by replacing the above structural site X is the cation site M １ ＋ to H ＋ HA is obtained by replacing it with １ The acid dissociation constant a1 originates from the acidic site represented by the above structure site Y, and the cation site M in the above structural site Y. ２ ＋ to H ＋HA is obtained by replacing it with ２ It has an acid dissociation constant a2 derived from the acidic site represented by the above, and the acid dissociation constant a2 is greater than the acid dissociation constant a1.

[0260] Condition I will be explained in more detail below. If compound (I) is a compound that generates an acid having, for example, one first acidic site derived from structural site X and one second acidic site derived from structural site Y, then compound PI is "HA １ and HA ２ This falls under the category of "compounds having the above characteristics". More specifically, when the acid dissociation constants a1 and a2 of compound PI are determined, compound PI is "A １ － and HA ２ The pKa at which the compound becomes "a compound having " is the acid dissociation constant a1, and the above "A １ － and HA ２ Compounds having "A" １ － and A ２ － The pKa value at which the compound becomes "a compound having the above characteristics" is the acid dissociation constant a2.

[0261] If compound (I) is a compound that generates an acid having, for example, two first acidic sites derived from structural site X and one second acidic site derived from structural site Y, then compound PI is "two HA １ and one HA ２ This falls under the category of "compounds having one A". When the acid dissociation constant of compound PI is determined, compound PI is "a compound having one A １ － and one HA １ and one HA ２ The acid dissociation constant when a compound having " and " is formed, and " １ － and one HA １ and one HA ２ Compounds having "two A １ － and one HA ２The acid dissociation constant when a compound having the two A's is obtained corresponds to the aforementioned acid dissociation constant a1. １ － and one HA ２ Compounds having "two A １ － and A ２ － The acid dissociation constant when a compound has the above-mentioned structure corresponds to the acid dissociation constant a2. In other words, in the case of compound PI, the above-mentioned cation site M in the above-mentioned structural site X. １ ＋ to H ＋ HA is obtained by replacing it with １ When a compound has multiple acid dissociation constants originating from the acidic site represented by , the value of acid dissociation constant a2 is greater than the largest of the multiple acid dissociation constants a1. １ － and one HA １ and one HA ２ Let aa be the acid dissociation constant when a compound having " １ － and one HA １ and one HA ２ Compounds having "two A １ － and one HA ２ When the acid dissociation constant for a compound having the above is denoted as ab, the relationship between aa and ab satisfies aa < ab.

[0262] The acid dissociation constants a1 and a2 are determined by the acid dissociation constant measurement method described above. The compound PI mentioned above corresponds to the acid generated when compound (I) is irradiated with active light or radiation. If compound (I) has two or more structural sites X, the structural sites X may be the same or different. Also, two or more of the above A １ － , and two or more of the above M １ ＋ These may be the same or different. In compound (I), the above A １ － and A above ２ － , and the above M １ ＋and the above M ２ ＋ These may be the same or different, but A above １ － and A above ２ － It is preferable that they are all different.

[0263] In the above compound PI, the difference (absolute value) between the acid dissociation constant a1 (the maximum value if 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. There is no particular upper limit to the difference (absolute value) between the acid dissociation constant a1 (the maximum value if there are multiple acid dissociation constants a1) and the acid dissociation constant a2, but for example, it is 16 or less.

[0264] In the above compound PI, the acid dissociation constant a2 is preferably 20 or less, and more preferably 15 or less. The lower limit of the acid dissociation constant a2 is preferably -4.0 or higher.

[0265] In the above 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 higher.

[0266] Anion part A １ － and anion part A ２ － This is a structural site containing a negatively charged atom or group of atoms, and examples include structural sites selected from the group consisting of formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6) shown below. Anion site A １ － As such, those that can form an acidic moiety with a small acid dissociation constant are preferred, and among these, those of formula (AA-1) to (AA-3) are more preferred, and those of formula (AA-1) and (AA-3) are even more preferred. Also, anion moiety A ２ － For example, Anion part A １ －It is preferable that the acidic site can form an acidic site with a larger acid dissociation constant than the above, more preferably one of formulas (BB-1) to (BB-6), and even more preferably one of formulas (BB-1) and (BB-4). In formulas (AA-1) to (AA-3) and (BB-1) to (BB-6) below, * represents the bond position. In formula (AA-2), R Ａ R represents a monovalent organic group. Ａ The monovalent organic group represented by is not particularly limited, but examples include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

[0267]

[0268]

[0269] Cation site M １ ＋ and cation site M ２ ＋ This is a structural site containing a positively charged atom or group of atoms, for example, a monovalent organic cation. Examples of organic cations include M, as described in the description of other photoacid generators above. ＋ Examples include the same organic cations represented by [the formula shown].

[0270] (Compound (II)) Compound (II) is a compound having two or more of the above-mentioned structural sites X and one or more of the following structural sites Z, which generates an acid containing two or more of the above-mentioned first acidic sites derived from the above-mentioned structural sites X and the above-mentioned structural sites Z upon irradiation with active light or radiation. Structural site Z: A nonionic site capable of neutralizing acid

[0271] Definition of structural site X in compound (II), and A １ － and M １ ＋ The definition of is the definition of structural site X in compound (I) as described above, and A １ － and M １ ＋ This is synonymous with the definition of [the specified term], and the preferred embodiment is also the same.

[0272] In the above compound (II), the above cation moiety M in the above structural moiety X. １ ＋ to H ＋ In compound PII, which is obtained by replacing the above structural site X, the above cation site M １ ＋ to H ＋ HA is obtained by replacing it with １ The preferred range for the acid dissociation constant a1 derived from the acidic site represented by is the same as the acid dissociation constant a1 in compound PI. Note that if compound (II) is, for example, a compound that generates an acid having two of the first acidic sites derived from the structural site X and the structural site Z, then compound PII is "two HA １ This falls under the category of "a compound having one A". When the acid dissociation constant of this compound PII is determined, compound PII is "a compound having one A １ － and one HA １ The acid dissociation constant when a compound having " and " is formed, and " １ － and one HA １ Compounds having "two A １ － The acid dissociation constant when the compound becomes "a compound having " corresponds to the acid dissociation constant a1.

[0273] The acid dissociation constant a1 is determined by the acid dissociation constant measurement method described above. Compound PII refers to the acid generated when compound (II) is irradiated with active light or radiation. The two or more structural sites X may be the same or different. Two or more of the above A １ － , and two or more of the above M １ ＋ These may be the same or different.

[0274] The nonionic site in structural site Z that can neutralize the acid is not particularly limited, and is preferably a site containing a group that can electrostatically interact with a proton, or a functional group having electrons. Examples of groups that can electrostatically interact with a proton, or functional groups having electrons, include functional groups having a macrocyclic structure such as a cyclic polyether, or functional groups having a nitrogen atom with a lone pair of electrons that does not contribute to π-conjugation. A nitrogen atom having a lone pair of electrons that does not contribute to π-conjugation is, for example, a nitrogen atom having the substructure shown in the following formula.

[0275]

[0276] Examples of substructures of functional groups having a group or electron that can electrostatically interact with a proton include crown ether structures, azacrown ether structures, primary to tertiary amine structures, pyridine structures, imidazole structures, and pyrazine structures, among which primary to tertiary amine structures are preferred.

[0277] Examples of non-cationic moieties that compound (I) and compound (II) may have include the anions described in International Publication No. 2022 / 024928, paragraphs

[0277] to

[0280] , which are incorporated herein by reference.

[0278] The content of the photoacid generator 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, relative to the total solid content of the resist composition. Furthermore, the content of the photoacid generator is preferably 50.0% by mass or less, more preferably 45.0% by mass or less, even more preferably 40.0% by mass or less, particularly preferably 30.0% by mass or less, and most preferably 25.0% by mass or less, relative to the total solid content of the resist composition. Only one type of photoacid generator may be used, or two or more types may be used. When two or more types of photoacid generators are used, it is preferable that their total content is within the range of the above preferred content.

[0279] <<Acid Diffusion Control Agent>> The resist composition contains an acid diffusion control agent. The acid diffusion control agent can act as a quencher to trap excess acid generated from, for example, the photoacid generator described above by irradiation (exposure) with active light or radiation, and to suppress the reaction of the acid-degradable resin in the unexposed areas due to the excess acid. Note that the acid diffusion control agent is a different compound from the photoacid generator described above. Examples of the acid diffusion control agent include the specified sulfonium salt compound B described above and other acid diffusion control agents other than the specified sulfonium salt compound B. The resist composition preferably contains the specified sulfonium salt compound B as the acid diffusion control agent in terms of superior effects of the present invention.

[0280] <Other Acid Diffusion Controlling Agents> The types of other acid diffusion controlling agents are not particularly limited, but examples include compounds selected from basic compounds (CA), low molecular weight compounds (CB) having a nitrogen atom and a group that is eliminated by the action of an acid, and compounds (CC) whose acid diffusion controlling ability is reduced or lost by irradiation with active light or radiation.

[0281] Basic Compounds (CA) As basic compounds (CA), compounds having a structure represented by any of the following formulas (A) to (E) are preferred. In formulas (B), (C), (D), and (E), * indicates a bond position.

[0282]

[0283] In formula (A), R ２００ ~R ２０２ Each of these 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 (6 to 20 carbon atoms). ２００ ~R ２０２ At least two of them may be joined to form a ring. In formula (E), R ２０３ ~R ２０６ Each of these independently represents an alkyl group having 1 to 20 carbon atoms.

[0284] R in equations (A) and (E) ２００ , R ２０１ , R ２０２ , R ２０３ , R ２０４ , R２０５ and R ２０６ The alkyl group or cycloalkyl group represented by may have substituents. Preferred substituent alkyl groups include C1-C20 aminoalkyl groups, C1-C20 hydroxyalkyl groups, or C1-C20 cyanoalkyl groups. In formulas (A) and (E), R ２００ , R ２０１ , R ２０２ , R ２０３ , R ２０４ , R ２０５ and R ２０６ The alkyl group or cycloalkyl group represented by is preferably unsubstituted.

[0285] Examples of basic compounds (CA) include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine. The basic compound (CA) may also be a compound having at least one 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 (CA) may also be an alkylamine derivative having at least one selected from the group consisting of a hydroxyl group and an ether bond, or an aniline derivative having at least one selected from the group consisting of a hydroxyl group and an ether bond.

[0286] The difference between the pKa of the conjugate acid of the basic compound (CA) 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 (CA)) is preferably 1.00 or higher, more preferably 1.00 to 14.00, and even more preferably 2.00 to 13.00. Furthermore, the pKa of the conjugate acid of the basic compound (CA) is preferably, for example, 1.00 to 14.00, more preferably 3.00 to 13.00, and even more preferably 3.50 to 12.50.

[0287] Specific examples of basic compounds (CA) include, for example, the compounds described in paragraphs

[0132] to

[0136] of International Publication No. 2020 / 066824, which are incorporated herein by reference. Specific examples of low molecular weight compounds (CB) having a nitrogen atom and a group that is eliminated by the action of an acid include the compounds described in paragraphs

[0156] to

[0163] of International Publication No. 2020 / 066824, which are incorporated herein by reference.

[0288] Compounds (CC) whose acid diffusion control ability is reduced or lost by irradiation with active light or radiation. Specifically, examples of compounds (CC) include onium salts (CD) of acids that are relatively weak acids with respect to the acid generated from the above-mentioned photoacid generator, and basic compounds (CE) whose basicity is reduced or lost by irradiation with active light or radiation.

[0289] Compound (CD) may be a compound that generates acid upon exposure. Preferably, compound (CD) is a compound that generates an acid with a pKa of 1.00 or more greater than the acid generated from the photoacid generator. The difference between the pKa of the acid generated from compound (CD) and the pKa of the acid generated from the photoacid generator (the value obtained by subtracting the pKa of the acid generated from compound (N) or the photoacid generator from the pKa of the acid generated from compound (CD)) 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. Furthermore, the pKa of the acid generated from compound (CD) 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.

[0290] The compound (CD) is preferably an onium salt consisting of an anion and a cation. Examples of the compound (CD) include "M ＋ X － Examples include compounds represented by " (onium salts). ＋ represents a cation, preferably an organic cation. ＋ Examples include the same cations described above in relation to other photoacid generators. －X represents an anion, preferably an organic anion. － Examples include the anion described in the above-mentioned specific sulfonium salt compound B.

[0291] In particular, when the above compound (CC) is an onium salt (CD) that is relatively weak acid with respect to the acid generated from the above photoacid generator, it is preferable that the above onium salt (CD) is a compound containing an anion part represented by any of the following formulas (BB-1) to (BB-7).

[0292]

[0293] Specific examples of onium salts (CD) include, for example, the compounds described in paragraphs

[0305] to

[0314] of International Publication No. 2020 / 158337, which are incorporated herein by reference. Specific examples of basic compounds (CE) include those described in paragraphs

[0137] to

[0155] and paragraph

[0164] of International Publication No. 2020 / 066824, which are incorporated herein by reference.

[0294] In addition to the compounds described above, other known compounds disclosed in paragraphs

[0627] to

[0664] of U.S. Patent Application Publication 2016 / 0070167A1, paragraphs

[0095] to

[0187] of U.S. Patent Application Publication 2015 / 0004544A1, paragraphs

[0403] to

[0423] of U.S. Patent Application Publication 2016 / 0237190A1, and paragraphs

[0259] to

[0328] of U.S. Patent Application Publication 2016 / 0274458A1 can also be suitably used as acid diffusion control agents, and such descriptions are incorporated herein by reference.

[0295] The molecular weight of the other acid diffusion control agent is not particularly limited, but is preferably 100 to 3000, more preferably 150 to 2500, and even more preferably 200 to 2000.

[0296] The content of the acid diffusion control agent in the resist composition is 1.0% by mass or more, preferably 1.0 to 40.0% by mass, more preferably 1.0 to 30.0% by mass, and even more preferably 2.0 to 25.0% by mass, based on the total solid content of the resist composition. Only one type of acid diffusion control agent may be used, or two or more types may be used. When two or more types are used, it is preferable that their total content is within the range of the above preferred content.

[0297] In the resist composition, the content of the acid diffusion control agent relative to the photoacid generator (acid diffusion control agent / photoacid generator) is preferably 50 mol% or more, and more preferably 100 mol% or more, in terms of achieving superior effects of the present invention. The upper limit is preferably 500 mol% or less, and more preferably 300 mol% or less.

[0298] <<Hydrophobic Resin>> The resist composition may also contain a hydrophobic resin, which is a resin different from the acid-degradable resin described above. The hydrophobic resin is preferably designed to be unevenly distributed on the surface of the resist film, but unlike surfactants, it does not necessarily need to have hydrophilic groups in its molecule and does not need to contribute to the uniform mixing of polar and nonpolar substances.

[0299] Hydrophobic resins, in terms of their uneven distribution on the film surface, contain fluorine atoms, silicon atoms, and CH4 atoms in the side chain portion of the resin. ３ It is preferable that the substructure has one or more of these substructures, and more preferably two or more. Furthermore, 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 substituted in the side chain. Examples of hydrophobic resins include the compounds described in paragraphs

[0275] to

[0279] of International Publication No. 2020 / 004306, which are incorporated herein by reference.

[0300] When the resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01 to 20.0% by mass, more preferably 0.1 to 10.0% by mass, and even more preferably 0.1 to 5.0% by mass, based on the total solid 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, it is preferable that their total content is within the range of the above preferred content.

[0301] <<Surfactants>> The resist composition of the present invention may contain surfactants. By including surfactants, it is possible to form patterns with better adhesion and fewer development defects. Fluorine-based and / or silicone-based surfactants are preferred. Examples of fluorine-based and / or silicone-based surfactants include those disclosed in paragraphs

[0218] and

[0219] of International Publication No. 2018 / 193954.

[0302] If the resist composition contains a surfactant, the surfactant content is preferably 0.0001 to 2.0% by mass, more preferably 0.0005 to 1.0% by mass, and even more preferably 0.01 to 1.0% by mass, relative to the total solid content of the resist composition. One type of surfactant may be used, or two or more types may be used. If two or more types are used, it is preferable that their total content is within the above preferred content range.

[0303] <<Solvent>> The resist composition preferably contains a solvent. The solvent preferably contains (M1) propylene glycol monoalkyl ether carboxylate and (M2) at least one selected from the group consisting of propylene glycol monoalkyl ether, lactic acid ester, acetate ester, alkoxypropionic acid ester, linear ketone, cyclic ketone, lactone, and alkylene carbonate. The solvent may further contain components other than components (M1) and (M2). Details of components (M1) and (M2) are described in paragraphs

[0218] to

[0226] of International Publication No. 2020 / 004306, and these contents are incorporated herein by reference. The solvent content in the resist composition is preferably set so that the solid content concentration is 0.5 to 30% by mass, and more preferably 1 to 20% by mass. If the solvent further contains components other than components (M1) and (M2), the content of the components other than components (M1) and (M2) is preferably 5 to 30% by mass relative to the total amount of the solvent.

[0304] <<Other Additives>> The resist composition may further contain, as other additives, at least one selected from the group consisting of dissolution-inhibiting compounds, dyes, plasticizers, photosensitizers, light absorbers, and compounds that promote solubility in the developer (for example, phenol compounds with a molecular weight of 1000 or less, or alicyclic or aliphatic compounds containing a carboxyl group). The above-mentioned "dissolution-inhibiting compounds" are compounds with a molecular weight of 3000 or less that decompose due to the action of acid, thereby reducing their solubility in organic developers.

[0305] The content of 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, relative to 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 their total content is within the range of the above preferred content.

[0306] Furthermore, the resist composition may contain water as an impurity. When water is present as an impurity, a lower water content is preferable, but it may be present in an amount of 1 to 30,000 ppm by mass relative to the total resist composition. Furthermore, the resist composition may contain residual monomers as impurities (for example, monomers derived from raw material monomers used in the synthesis of the resin). When residual monomers are present as impurities, a lower residual monomer content is preferable, but it may be present in an amount of 1 to 30,000 ppm by mass relative to the total solid content of the resist composition.

[0307] [Pattern Forming Method and Resist Film] The pattern forming method of the present invention is not particularly limited as long as it is a method of forming a pattern using the resist composition of the present invention, but a preferred pattern forming method comprises the steps of (1) forming a resist film on a substrate with the resist composition of the present invention, (2) exposing the resist film, and (3) developing the exposed resist film using a developer. Each of the above steps will be described in detail below.

[0308] [Step (1)] Step (1) is a step of forming a resist film on a substrate using the resist composition of the present invention. Details of the resist composition used in Step (1) are as described above.

[0309] One method for forming a resist film on a substrate using a resist composition is to coat the resist composition onto the substrate. If necessary, it is preferable to filter the resist composition before coating. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.03 μm or less, even more preferably 0.01 μm or less, and particularly preferably 0.005 μm or less. The lower limit of the filter pore size is not particularly limited, but may be 0.001 μm or more. The material of the filter is not particularly limited, but if it is a polymer, it is preferably made of polyolefins such as polyethylene (PE) and polypropylene (PP) (including high density and ultra-high molecular weight); polyamides such as nylon 6 and nylon 66; polyimide (PI); polyamideimide; polyesters such as polyethylene terephthalate; polyethersulfone; cellulose; polyfluorocarbons such as polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkanes; derivatives of the above polymers; and more preferably at least one selected from the group consisting of polyolefins, polyamides, polyimides, polyamideimide, polyesters, polysulfones, cellulose, polyfluorocarbons and their derivatives. In addition to resins, diatomaceous earth, glass, etc. may also be used.

[0310] The resist composition may be filtered using one filter or a combination of two or more filters. If two or more filters are used, they may be the same filter or different filters. The resist composition may also be circulated and filtered repeatedly using the same filter.

[0311] The resist composition can be applied to a substrate (e.g., silicon, silicon coated with silicon dioxide, etc.) used in the manufacture of integrated circuit elements by a suitable coating method such as a spinner or coater. Spin coating using a spinner is preferred. The preferred rotation speed when spin coating using a spinner is 1000 to 3000 rpm (rotations per minute). After applying the resist composition, the substrate may be dried to form a resist film. If necessary, various undercoats (inorganic films, organic films, anti-reflective films, etc.) may be formed in the layer below the resist film.

[0312] As for drying methods, one example is drying by heating. Heating can be carried out using means provided in at least one of a normal exposure machine and a developer machine, and may also be carried out using a hot plate or the like. The heating temperature is not particularly limited, but is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is not particularly limited, but is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, and even more preferably 60 to 600 seconds.

[0313] The present invention also includes a resist film obtained in step (1). The thickness of the resist film is not particularly limited, but 10 to 120 nm is preferred in that it is possible to form finer patterns with higher precision. In particular, when EUV exposure is used, the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. 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.

[0314] A topcoat may be formed on the upper layer of the resist film using a topcoat composition. For example, it is preferable to form a topcoat containing a basic compound, such as that described in Japanese Patent Application Publication No. 2013-61648, on the resist film. Specific examples of basic compounds that the topcoat may contain include basic compounds that may be contained in the resist composition.

[0315] [Step (2)] Step (2) is a step of exposing the resist film formed in step (1). Methods of exposure include irradiating the formed resist film with active light or radiation through a predetermined mask. Examples of active light or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams, preferably with a wavelength of 250 nm or less, more preferably 220 nm or less, and particularly preferably far ultraviolet light with a wavelength of 1 to 200 nm, specifically KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ２ Examples include excimer lasers (157 nm), EUV (13.5 nm), X-rays, and electron beams. The resist composition of the present invention is particularly suitable for pattern formation by EUV exposure or electron beam (EB) exposure. In other words, step (2) above is preferably a step of exposing the resist film with extreme ultraviolet light or an electron beam.

[0316] It is preferable to bake (heat) the image after exposure but before developing. This step is also called post-exposure baking (PEB). Baking promotes the reaction of the exposed area, resulting in better sensitivity and pattern shape. The baking temperature is not particularly limited, but is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The baking time is not particularly limited, but is preferably 10 to 1000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. Heating can be carried out using means provided in at least one of a normal exposure machine and a developer, and may also be done using a hot plate or the like.

[0317] [Step (3)] Step (3) is a step in which the resist film exposed in step (2) is developed using a developer. By performing step (3), a resist pattern (also simply called a "pattern") is formed. The developer used in step (3) may be an alkaline developer or a developer containing an organic solvent (hereinafter also called an organic developer). Examples of development methods include immersing the substrate in a tank filled with developer for a certain period of time (dip method), puddling the developer on the substrate surface using surface tension and letting it stand for a certain period of time to develop (paddle method), spraying the developer onto the substrate surface (spray method), and continuously dispensing the developer while scanning a developer dispensing nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispensing method). The development time is preferably 10 to 300 seconds, and more preferably 20 to 120 seconds. The temperature of the developer is preferably 0 to 50°C, and more preferably 15 to 35°C. In step (3), a step of stopping development while substituting with another solvent may be performed.

[0318] It is preferable to use an alkaline aqueous solution containing alkali as the alkaline developer. The type of alkaline aqueous solution is not particularly limited, but examples include alkaline aqueous solutions containing quaternary ammonium salts represented by tetramethylammonium hydroxide, inorganic alkalis, primary amines, secondary amines, tertiary amines, alcohol amines, or cyclic amines. Among these, it is preferable that the alkaline developer be an aqueous solution of a quaternary ammonium salt represented by tetramethylammonium hydroxide (TMAH). Appropriate amounts of alcohols, surfactants, etc., may be added to the alkaline developer. The alkali 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.

[0319] The organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents.

[0320] The above organic solvents may be mixed in multiple quantities, or mixed with solvents other than the above organic solvents or with water. The water content of the organic 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 water-free. 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 organic developer.

[0321] The organic developer preferably contains butyl acetate (n-butyl acetate), and more preferably contains butyl acetate and a hydrocarbon having 9 to 12 carbon atoms. The hydrocarbon having 9 to 12 carbon atoms contained in the organic developer may be just one type or two or more types. The hydrocarbon having 9 to 12 carbon atoms is preferably at least one selected from the group consisting of alkanes, alkenes, alkynes and cycloalkanes, more preferably an alkane, even more preferably at least one selected from the group consisting of nonanes, decanes, undecanes and dodecanes, particularly preferably at least one selected from the group consisting of undecanes and dodecanes, and most preferably undecanes. The hydrocarbon having 9 to 12 carbon atoms may also contain structural isomers.

[0322] The butyl acetate content in the organic developer is preferably 65% ​​to 99% by mass, more preferably 70% to 95% by mass, and even more preferably 75% to 90% by mass, based on 100% by mass of the entire organic developer. The hydrocarbon content (total amount if multiple hydrocarbons with 9 to 12 carbon atoms are included) in the organic developer is preferably 1% to 35% by mass, more preferably 5% to 30% by mass, and even more preferably 10% to 25% by mass, based on 100% by mass of the entire organic developer.

[0323] The mass ratio of butyl acetate to hydrocarbons having 9 to 12 carbon atoms in the organic developer (butyl acetate content / hydrocarbon content having 9 to 12 carbon atoms) is preferably 60 / 40 to 95 / 5, more preferably 70 / 30 to 95 / 5, even more preferably 80 / 20 to 90 / 10, and particularly preferably 90 / 10.

[0324] Organic developers may contain other components in addition to butyl acetate and hydrocarbons having 9 to 12 carbon atoms. Examples of other components include water, organic solvents other than butyl acetate and hydrocarbons having 9 to 12 carbon atoms, surfactants, antioxidants, and basic compounds.

[0325] [Other steps] The pattern forming method of the present invention may include other steps other than those described above.

[0326] <Rinsing Step> After step (3), rinsing may be performed. The rinsing solution is not particularly limited as long as it does not dissolve the pattern, and a solution containing a general solvent can be used. The rinsing solution preferably contains at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

[0327] The rinsing method is not particularly limited and includes, for example, a method in which rinsing liquid is continuously discharged onto a substrate rotating at a constant speed (rotary coating method), a method in which the substrate is immersed in a tank filled with rinsing liquid for a certain period of time (dip method), and a method in which rinsing liquid is sprayed onto the surface of the substrate (spray method).

[0328] Furthermore, the pattern formation method of the present invention may include a heating step (PB; Post Bake) after step (3). This step removes any developer and rinse solution remaining between and inside the patterns. This step also has the effect of mellowing the resist pattern and improving the surface roughness of the pattern. The heating step after step (3) may be performed, for example, at 40 to 250°C (preferably 90 to 200°C) for, for example, 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

[0329] Alternatively, the formed pattern may be used as a mask to perform an etching process on the substrate. In other words, the pattern formed in step (3) may be used as a mask to process the substrate (or the underlying film and substrate) to form a pattern on the substrate. The method of processing the substrate (or the underlying film and substrate) is not particularly limited, but a preferred method is to form a pattern on the substrate by performing dry etching on the substrate (or the underlying film and substrate) using the pattern formed in step (3) as a mask. Dry etching is not particularly limited, but oxygen plasma etching is preferred.

[0330] In the pattern forming method of the present invention, the developer, resist composition, and other various materials (e.g., solvent, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) used are preferably free of impurities such as metals. The impurity content in these materials is preferably 1 ppm (parts per million) or less, more preferably 10 ppb (parts per billion) or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably 1 ppt or less. The lower limit of the impurity content is not particularly limited and may be 0 ppt or more. 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.

[0331] Methods for reducing impurities such as metals contained in various materials include, for example, selecting raw materials with a low metal content as constituent materials for various materials, performing filter filtration on the constituent materials of various materials, and performing distillation under conditions that suppress contamination as much as possible, such as by lining the inside of the apparatus with Teflon®. Details of filtration using filters are described in paragraph

[0321] of International Publication No. 2020 / 004306.

[0332] In addition to filter filtration, impurities may be removed using adsorbents, or a combination of filter filtration and adsorbents may be used. Known adsorbents can be used, such as inorganic adsorbents like silica gel and zeolite, and organic adsorbents like activated carbon. To reduce impurities such as metals contained in the above materials, it is necessary to prevent the introduction 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 in the cleaning solution used to clean the equipment. The content of metal components in the cleaning solution after use is preferably 100 ppt by mass or less, more preferably 10 ppt by mass or less, and even more preferably 1 ppt by mass or less. There is no particular lower limit, but 0 ppt by mass or more is preferred.

[0333] [Method for Manufacturing Electronic Devices] This specification relates to a method for manufacturing electronic devices, including the pattern forming method of the present invention described above, and to electronic devices manufactured by this manufacturing method. Preferred embodiments of the electronic devices of this specification include those mounted on electrical and electronic equipment (home appliances, OA (Office Automation), media-related equipment, optical equipment, and communication equipment, etc.).

[0334] The present invention will be described in more detail below based on the following examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples.

[0335] [Various Components of Photosensitive or Radiation-Sensitive Resin Compositions] [Resins] The resins (resins MP-1 to MP-10) shown in Table 2 are described below. The resins used are MP-1 to MP-10 synthesized according to known methods. Table 1 shows the composition ratio, weight-average molecular weight (Mw), and dispersion (Mw / Mn) of each repeating unit. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) of resins MP-1 to MP-10 can be measured by GPC (carrier: tetrahydrofuran (THF)) (in polystyrene equivalent). The composition ratio (weight % ratio) of the resins is as follows: １３It can be measured using C-NMR (nuclear magnetic resonance).

[0336]

[0337] The structures of the repeating units M-1 to M-10 shown in Table 1 are shown below.

[0338]

[0339] [Photoacid Generator] The photoacid generator shown in Table 2 is an onium salt compound composed of a cationic part and an anionic part shown in Table 2. The cationic part (catenic parts C-1 to C-14, RC-1 to RC-2) and anionic part (anionic parts RA-1 to RA-3, RRA-1 to RRA-2) that constitute the photoacid generator shown in Table 2 are shown below. <Cationic part>

[0340]

[0341]

[0342] <Anime Club>

[0343] The pKa values ​​of the proton adducts of each of the above anionic parts (RA-1 to RA-3, RRA-1, RRA-2) are as follows. Note that the proton adduct of each anionic part corresponds to the acid produced from the photoacid generator having each anionic part upon exposure. For example, the photoacid generator having anionic part RA-1 produces an acid with a pKa of -0.22 upon exposure. pKa of the proton adduct of the anionic part of RA-1: -0.22 pKa of the proton adduct of the anionic part of RA-2: -0.20 pKa of the proton adduct of the anionic part of RA-3: -0.63 pKa of the proton adduct of the anionic part of RRA-1: -3.30 pKa of the proton adduct of the anionic part of RRA-2: -3.91

[0344] 《Synthesis of Cation C-6》 Cation C-6 was synthesized based on the following scheme.

[0345]

[0346] Magnesium (1.26 g) was added to tetrahydrofuran (45 mL) to obtain a mixture. 4-bromo-N,N-dimethylaniline (8.90 g) was added dropwise to the mixture. The mixture was then stirred for 1 hour to prepare Grignard Reagent A. The resulting mixture was cooled to 0°C, diphenyl sulfoxide (3.0 g) was added to the THF solution of Grignard Reagent A prepared above, and trimethylsilyl chloride (4.0 g) was added dropwise to the mixture. The resulting mixture was heated to room temperature and stirred for 1.5 hours. 1.0 mol / L hydrobromic acid aqueous solution (60 mL) was added to the mixture while maintaining the temperature of the mixture at 0°C. The resulting mixture was washed with diisopropyl ether (80 mL) and ethyl acetate (50 mL), and then extracted with methylene chloride (100 mL) to obtain cation C-6.

[0347] 《Synthesis of cation moieties other than cation C-6》 Other cations other than cation C-6 can be synthesized by the same procedure as the synthesis method described above.

[0348] [Acid Diffusion Control Agents] The acid diffusion control agents shown in Table 2 are onium salt compounds composed of a cationic part and an anionic part shown in Table 2. The cationic part (catenic parts C-1 to C-14, RC-1 to RC-2) and anionic part (anionic parts RQ-1 to RQ-2) that constitute the acid diffusion control agents shown in Table 2 are shown below.

[0349] <Cation part> The cation part is the same as the cation parts (cation parts C-1 to C-14, RC-1 to RC-2) that make up the photoacid generator described above. <Anion part>

[0350]

[0351] [Hydrophobic Resins] The hydrophobic resins (Resin AP-1) shown in Table 2 are described below. In the structural formulas of the hydrophobic resins shown below, the content of each repeating unit is the content ratio (mol%) of each repeating unit to the total number of repeating units.

[0352]

[0353] [Surfactants] The surfactants shown in Table 2 are listed below. W-1: Megafac R08 (manufactured by Dainippon Ink and Chemicals, Inc.)

[0354] [Solvents] S-1: Propylene glycol monomethyl ether acetate (PGMEA: 1-methoxy-2-acetoxypropane) S-2: Propylene glycol monomethyl ether (PGME: 1-methoxy-2-propanol) S-3: Ethyl lactate S-4: γ-butyrolactone

[0355] [Preparation of Resist Compositions] The components shown in Table 2 below are dissolved in the solvents shown in the table to prepare solutions at the solid content concentrations shown in Table 2. These solutions are then filtered through a polyethylene filter with a pore size of 0.02 μm to prepare the resist compositions (R-1 to R-28, RR-1 to RR-4). In the table, the "Content (mass %)" column indicates the content (mass ratio) of each component relative to the total solid content in the resist composition. Solid content refers to components other than the solvent. In resist compositions using surfactants, the surfactant content is set to 0.1 mass %. The "mass ratio" of the solvent is the content of each solvent listed in the "Type" column relative to the total solvent (total content of the solvents listed in the "Type" column). In Table 2, the "Molar Ratio (%)" column indicates the molar ratio (%) of the acid diffusion control agent content to the photoacid generator content in each resist composition. The molar ratio (%) was calculated as (amount of substance of acid diffusion control agent / amount of substance of photoacid generator) × 100 (%).

[0356]

[0357]

[0358] [Evaluation 1] [Pattern Formation Method (EB Exposure)] A resist composition is applied to a 6-inch Si wafer that has been pre-treated with hexamethyldisilazane (HMDS) using a Tokyo Electron Mark 8 spin coater, and dried on a hot plate at 100°C for 60 seconds to obtain a resist film with a thickness of 100 nm. Here, 1 inch is 0.0254 m. Similar results can be obtained by changing the Si wafer to a chromium substrate. The wafer coated with the resist film obtained above is subjected to pattern irradiation using an electron beam lithography system (Hitachi Ltd. HL750, acceleration voltage 50 keV). At this time, drawing is performed so that a 1:1 line and space pattern is formed. After electron beam lithography, post-exposure heating (PEB) is performed by heating on a hot plate at 110°C for 60 seconds, developing with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide for 30 seconds, rinsing with pure water, rotating the wafer at 4000 rpm for 30 seconds, and then heating at 95°C for 60 seconds to obtain a resist pattern with a 1:1 line-and-space pattern and a line width of 50 nm.

[0359] [LWR Evaluation Method] A line-and-space pattern with a line width of 50 nm (line / space = 1 / 1) resolved by the method described above is observed from above using a length-measuring scanning electron microscope (SEM (Hitachi S-9380II)). The line width of the pattern is observed at arbitrary points (160 points), and the measurement variability of 3σ (nm) is evaluated as the LWR value. A smaller value indicates better performance.

[0360] [Bake Temperature Dependence] In the pattern formation method described above, after irradiation with the optimal exposure dose, post-exposure heating is performed at two temperatures: +5°C and -5°C (i.e., 115°C and 105°C) relative to the post-exposure heating temperature. The resulting line and space patterns are measured, and their line widths L1 and L2 are determined. The bake temperature dependence is defined as the change in line width per 1°C temperature change during baking, and is calculated using the following formula (1). Formula (1) Bake temperature dependence (nm / °C) = |L1 - L2| / 10 Next, the calculated values ​​are evaluated against the following evaluation criteria. Note that a smaller bake temperature dependence value indicates smaller and better performance, and for practical purposes, a value of "B" or higher is preferable. A: 0.2 or less B: Greater than 0.2, 0.4 or less C: Greater than 0.4, 0.8 or less D: Greater than 0.8

[0361]

[0362] The results in Table 3 clearly show that the resist compositions of the examples exhibit little dependence on the heating temperature after exposure. Furthermore, the results of the examples confirm that when the content (mol% ratio) of the acid diffusion control agent relative to the photoacid generator is 50 mol% or more, the dependence on the heating temperature after exposure becomes even smaller, and the LWR of the formed pattern is even better (see the results of Examples 1-12 and 1-13 in particular).

[0363] [Evaluation 2] [Pattern Formation Method (EUV Exposure)] A base layer formation composition AL412 (manufactured by Brewer Science) is applied to a silicon wafer and baked at 205°C for 60 seconds to form a base layer with a thickness of 20 nm. A resist composition shown in Table 2 is then applied on top of this and baked at 100°C for 60 seconds to form a resist film with a thickness of 50 nm. Pattern irradiation is performed on the silicon wafer having the obtained resist film using an EUV exposure apparatus (Exitech, Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36). A mask with a line size of 50 nm and a line:space ratio of 1:1 is used as the rectil. After exposure, the resist film is baked at 100°C for 60 seconds, then developed with an aqueous solution of tetramethylammonium hydroxide (2.38% by mass) for 30 seconds, followed by rinsing with pure water for 30 seconds. Finally, it is spin-dried to obtain a positive-type pattern.

[0364] The evaluation is performed using the same method as described in [Evaluation 1] [LWR Evaluation Method] and [Bake Temperature Dependence] above. The evaluation results are shown in Table 4.

[0365]

[0366] The results in Table 4 clearly show that the resist compositions of the examples exhibit little dependence on the heating temperature after exposure. Furthermore, the results of the examples confirm that when the content (mol% ratio) of the acid diffusion control agent relative to the photoacid generator is 50 mol% or more, the dependence on the heating temperature after exposure becomes even smaller, and the LWR of the formed pattern is even better (see the results of Examples 2-12 and 2-13 in particular).

Claims

1. A photosensitive or radiation-sensitive resin composition comprising a resin, a photoacid generator, and an acid diffusion controller, wherein at least one of the photoacid generator and the acid diffusion controller is a compound represented by formula (1). In the formula, Ar １ to Ar ３ each independently represents a monovalent aromatic ring group which may have a substituent or an alkyl group which may have a substituent. However, at least one of Ar １ to Ar ３ represents a monovalent nitrogen-containing aromatic ring group which may have a substituent or a group represented by formula (2). Incidentally, two of Ar １ to Ar ３ may be bonded to each other via a single bond or a divalent linking group. Z － represents an anion. However, the anion does not contain *-C(R Ｆ１ )(R Ｆ２ )-SO ３ － . R Ｆ１ and R Ｆ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. * represents a bonding position. In the formula, Ar ４ represents an l + 1-valent aromatic ring group which may have a substituent other than a group represented by -N(R Ｔ３ )(R Ｔ４ ). R Ｔ３ and R Ｔ４ each independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group which may have a substituent other than an acid-decomposable group, a monovalent aromatic ring group which may have a substituent other than an acid-decomposable group, or a monovalent aliphatic heterocyclic group which may have a substituent other than an acid-decomposable group. Incidentally, R Ｔ３ and R Ｔ４ may be bonded to each other to form a ring which may have a substituent. The wavy line represents a bonding position. Incidentally, when there are a plurality of R Ｔ３ , the plurality of R Ｔ３ may be the same as or different from each other. When there are a plurality of R Ｔ４ , the plurality of R Ｔ４ The terms may be identical or different from each other. l represents an integer greater than or equal to 1.

2. The light-sensitive or radiation-sensitive resin composition according to claim 1, wherein the resin comprises repeating units having groups that decompose upon the action of an acid and increase in polarity.

3. The photosensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the resin comprises repeating units having phenolic hydroxyl groups.

4. The photosensitive or radiation-sensitive resin composition according to claim 2, wherein the repeating unit having a group that decomposes and increases in polarity due to the action of the acid includes a repeating unit represented by formula (B1). In formula (B1), R ｂ１ and R ｂ２ Each of these independently represents a hydrogen atom or an alkyl group which may have a substituent. ｂ１ Ar represents a single bond or a -COO- bond. ｂ１ This represents an s+t+1 valent aromatic ring group. ｂ１ is, -OR ｂ or -COOR ｂ Represents R ｂ R represents a leaving group. ｂ３ is, -OR ｂ and -COOR ｂ Represents a substituent different from the given one. s represents an integer greater than or equal to 1. t represents an integer greater than or equal to 0. R ｂ１ and Ar ｂ１ They may be bonded to each other via single bonds or divalent linking groups to form a ring, R ｂ and R ｂ３ They may be bonded to each other via single bonds or divalent linking groups to form a ring, R ｂ３ They may be bonded to each other via single bonds or divalent linking groups to form a ring, R ｂ These elements may be linked to each other via single bonds or divalent linking groups to form a ring.

5. The photoacid generator generates an acid with a pKa of -2.0 or more and 1.5 or less upon irradiation with active light or radiation, the photoacid generator according to claim 1 or 2.

6. The Z in formula (1) － The photosensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the organic anion is represented by formula (a-1). In the formula, Ar ａ１ This represents a monovalent aromatic ring group which may have substituents, or a monovalent aliphatic hydrocarbon group which may have substituents.

7. The Z in formula (1) － The photosensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the organic anion is represented by formula (b-1). In the formula, Ar ｂ１ This represents a monovalent aromatic ring group which may have substituents.

8. The photosensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the content of the acid diffusion control agent relative to the photoacid generator is 50 mol% or more.

9. The photosensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the content of the acid diffusion control agent relative to the photoacid generator is 100 mol% or more.

10. A photosensitive or radiation-sensitive film formed using the photosensitive or radiation-sensitive resin composition according to claim 1 or 2.

11. A pattern forming method comprising the steps of: forming a resist film on a substrate using the photosensitive or radiation-sensitive resin composition described in claim 1 or 2; exposing the resist film; and developing the exposed resist film using a developer.

12. A method for manufacturing an electronic device, comprising the pattern forming method described in claim 11.

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