Pattern formation method, active light ray-sensitive or radiation-sensitive resin composition, and method for producing electronic device

Abstract

This pattern formation method includes (1) a step for forming a film using an active light ray-sensitive or radiation-sensitive resin composition that contains an acid-dissociable resin (P) and a photo-acid generator, (2) a step for exposing the film to light, and (3) a step for developing the exposed film using an organic processing liquid, wherein the acid-dissociable resin (P) includes at least four types of repeating unit, and among these at least four types of repeating unit, one type is a repeating unit (U1) having a specific structure and at least one type is a repeating unit (U2) having a specific structure, and the organic processing liquid contains butyl acetate and a hydrocarbon having 9-12 carbon atoms. Also provided are the active light ray-sensitive or radiation-sensitive resin composition, and a method for producing an electronic device, the method including the pattern formation method.

Description

Pattern forming method, actinic ray-sensitive or radiation-sensitive resin composition, and method for manufacturing electronic device

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

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

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

[0004] Patent Document 1 describes a method for producing a resist pattern by forming a composition layer using a resist composition containing a specific carboxylic acid generator, exposing the composition layer to electron beams, and developing the composition layer with butyl acetate.

[0005] Japanese Patent Application Publication No. 2023-156260

[0006] Recently, with the trend toward finer patterns, the performance required of resist compositions and pattern forming methods has become increasingly higher.

[0007] An object of the present invention is to provide a pattern forming method and an actinic ray-sensitive or radiation-sensitive resin composition having excellent resolution, and a method for manufacturing an electronic device including the pattern forming method.

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

[0009] [1] A pattern formation method comprising: (1) a step of forming a film using an actinic ray-sensitive or radiation-sensitive resin composition containing an acid-decomposable resin (P) and a photoacid generator; (2) a step of exposing the film to light; and (3) a step of developing the exposed film with an organic treatment liquid, wherein the acid-decomposable resin (P) contains at least four types of repeating units, and of the at least four types of repeating units, one type is a repeating unit (U1) represented by formula (I) and at least one type is a repeating unit (U2) represented by formula (II), and the organic treatment liquid contains butyl acetate and a hydrocarbon having from 9 to 12 carbon atoms.

[0010]

[0011] In formula (II), R １ represents a hydrogen atom, a halogen atom or an alkyl group, R ２represents a group that is cleaved by the action of an acid. [2] The pattern formation method according to [1], wherein the repeating unit having a group that is cleaved by the action of an acid, contained in the acid-decomposable resin (P), is the repeating unit (U2). [3] The pattern formation method according to [1] or [2], wherein the photoacid generator contains an iodine atom. [4] The pattern formation method according to any one of [1] to [3], wherein the photoacid generator is an onium salt, and the onium salt contains a cation having a fluorine atom. [5] The pattern formation method according to any one of [1] to [4], wherein the photoacid generator is an onium salt, and the onium salt contains an anion having an iodine atom. [6] The pattern formation method according to any one of [1] to [5], wherein the acid-decomposable resin (P) contains at least one group selected from the group consisting of a polycyclic lactone group and a polycyclic sultone group. [7] The pattern formation method according to any one of [1] to [6], wherein the acid-decomposable resin (P) contains an alicyclic group having two or more hydroxy groups. [8] The pattern formation method according to any one of [1] to [7], wherein the acid-decomposable resin (P) contains repeating units having a group that is cleaved by the action of an acid in an amount of more than 50 mol % based on all repeating units. [9] The pattern formation method according to any one of [1] to [8], wherein the acid-decomposable resin (P) contains repeating units (U1) in an amount of more than 30 mol % based on all repeating units.

[10] An actinic ray-sensitive or radiation-sensitive resin composition containing an acid-decomposable resin (P) and a photoacid generator, wherein the acid-decomposable resin (P) contains at least four repeating units, one of which is a repeating unit (U1) represented by formula (I) and at least one of which is a repeating unit (U2) represented by formula (II), and the actinic ray-sensitive or radiation-sensitive resin composition is used to form a pattern by development with an organic processing liquid containing butyl acetate and a hydrocarbon having from 9 to 12 carbon atoms.

[0012]

[0013] In formula (II), R １ represents a hydrogen atom, a halogen atom or an alkyl group, R ２represents a group that is eliminated by the action of an acid.

[11] A method for producing an electronic device, comprising the pattern formation method according to any one of [1] to [9].

[0014] The present invention can provide a pattern forming method and an actinic ray-sensitive or radiation-sensitive resin composition having excellent resolution. The present invention can also provide a method for manufacturing an electronic device including the pattern forming method.

[0015] The present invention will be described in detail below. The following description of the components will be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0016] In this specification, "actinic rays" or "radiation" refers to, for example, the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays (EUV), X-rays, soft X-rays, and electron beams (EB). In this specification, "light" refers to actinic rays or radiation. Unless otherwise specified, in this specification, "exposure" includes not only exposure using the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays, X-rays, and EUV, but also drawing using particle beams such as electron beams and ion beams. In this specification, the word "to" is used to mean that the numerical values ​​before and after it are included as the lower and upper limits.

[0017] In this specification, (meth)acrylate refers to at least one of acrylate and methacrylate, and (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid.

[0018] In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (also referred to as molecular weight distribution) (Mw / Mn) of a resin are defined as polystyrene-equivalent values ​​measured by gel permeation chromatography (GPC) using a GPC apparatus (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40° C., flow rate: 1.0 mL / min, detector: differential refractive index detector).

[0019] In the description of groups (atomic groups) in this specification, unless contrary to the spirit of the present invention, notations that do not specify whether they are substituted or unsubstituted include groups that contain a substituent as well as groups that do not have a substituent. For example, the term "alkyl group" includes not only alkyl groups that do not have a substituent (unsubstituted alkyl groups) but also alkyl groups that have a substituent (substituted alkyl groups). Furthermore, the term "organic group" in this specification refers to a group containing at least one carbon atom. Unless otherwise specified, a monovalent substituent is preferred as the substituent. Examples of the substituent include monovalent non-metallic atomic groups excluding hydrogen atoms, which can be selected, for example, from the following substituents T:

[0020] (Substituent T) Examples of the substituent T include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; alkoxy groups such as a methoxy group, an ethoxy group, and a tert-butoxy group; a cycloalkyloxy group; an aryloxy group such as a phenoxy group and a p-tolyloxy group; an alkoxycarbonyl group such as a methoxycarbonyl group and a butoxycarbonyl group; a cycloalkyloxycarbonyl group; an aryloxycarbonyl group such as a phenoxycarbonyl group; an acyloxy group such as an acetoxy group, a propionyloxy group, and a benzoyloxy group; an acetyl group, a benzoyl group, an isobutyryl group, an acryloyl group, a methacrylate group, a methyl ... Examples of the substituent T include acyl groups such as thiazolyl and methoxalyl groups; sulfanyl groups; alkylsulfanyl groups such as methylsulfanyl and tert-butylsulfanyl groups; arylsulfanyl groups such as phenylsulfanyl and p-tolylsulfanyl groups; alkylsulfonyl groups; arylsulfonyl groups; alkyl groups; alkenyl groups; cycloalkyl groups; aryl groups; heteroaryl groups; hydroxy groups; carboxyl groups; formyl groups; sulfo groups; cyano groups; alkylaminocarbonyl groups; arylaminocarbonyl groups; sulfonamide groups; silyl groups; amino groups; carbamoyl groups; etc. In addition, when these substituents can further have one or more substituents, examples of the substituent T also include groups having one or more substituents selected from the above-mentioned substituents as the further substituents (e.g., monoalkylamino groups, dialkylamino groups, arylamino groups, trifluoromethyl groups, etc.).

[0021] In this specification, the bonding direction of a divalent group is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "X-Y-Z", Y may be -CO-O- or -O-CO-. The compound may be either "X-CO-O-Z" or "X-O-CO-Z".

[0022] In this specification, the acid dissociation constant (pKa) refers to the pKa in an aqueous solution, and specifically, is a value determined by calculation using the following software package 1 based on a database of Hammett's substituent constants and known literature values. All pKa values ​​described in this specification are values ​​determined by calculation using this software package. Software package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0023] The pKa can also be calculated by molecular orbital calculation. A specific method for this is to calculate the pKa of H in an aqueous solution based on the thermodynamic cycle. ＋ One method is to calculate the dissociation free energy. ＋ The dissociation free energy can be calculated by, for example, DFT (density functional theory), but various other methods have been reported in the literature, and the method is not limited to these. There are several software programs that can perform DFT, and Gaussian 16 is an example.

[0024] In this specification, pKa refers to a value calculated based on a database of Hammett's substituent constants and publicly known literature values ​​using software package 1, as described above, but if pKa cannot be calculated by this method, a value obtained by Gaussian 16 based on DFT (density functional theory) will be adopted. In this specification, pKa refers to "pKa in aqueous solution" as described above, but if pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" will be adopted.

[0025] In this specification, the term "solid content" refers to components contained in the actinic ray-sensitive or radiation-sensitive resin composition and that form an actinic ray-sensitive or radiation-sensitive film, and does not include solvents. Furthermore, any component contained in the actinic ray-sensitive or radiation-sensitive resin composition and that forms an actinic ray-sensitive or radiation-sensitive film is considered to be a solid content even if it is in a liquid state.

[0026] <Pattern Forming Method> The pattern forming method of the present invention is a pattern forming method comprising: (1) a step of forming a film using an actinic ray-sensitive or radiation-sensitive resin composition containing an acid-decomposable resin (P) and a photoacid generator; (2) a step of exposing the film to light; and (3) a step of developing the exposed film with an organic treatment liquid, in which the acid-decomposable resin (P) contains at least four types of repeating units, and of the at least four types of repeating units, one type is a repeating unit (U1) represented by formula (I) and at least one type is a repeating unit (U2) represented by formula (II), and the organic treatment liquid contains butyl acetate and a hydrocarbon having from 9 to 12 carbon atoms.

[0027]

[0028] In formula (II), R １ represents a hydrogen atom, a halogen atom or an alkyl group, R ２ represents a group that is eliminated by the action of an acid.

[0029] Although the details of the mechanism by which the pattern forming method of the present invention provides excellent resolution are not clear, the present inventors speculate as follows. However, the present invention is not limited in any way by the speculated mechanism below. When forming a pattern by an organic solvent development process using a resist composition containing an acid-decomposable resin, it is believed that the developer may penetrate into and swell the resist film formed using the resist composition, which may result in failure to achieve the expected resolution. In the present invention, by using an organic processing liquid containing butyl acetate and a hydrocarbon having from 9 to 12 carbon atoms as the developer, it is believed that penetration of the developer into the resist film and swelling can be suppressed, thereby improving resolution. Furthermore, in the present invention, it is believed that by using a resin containing at least four types of repeating units, including a repeating unit having a specific structure, as the acid-decomposable resin, it is possible to reduce local bias in the repeating units, reduce areas prone to swelling, and further improve resolution.

[0030] Each of the above steps will be described in detail below.

[0031] [Step (1)] Step (1) is a step of forming a film using an actinic ray-sensitive or radiation-sensitive resin composition containing an acid-decomposable resin (P) and a photoacid generator. The actinic ray-sensitive or radiation-sensitive resin composition used in step (1) is typically a resist composition. The actinic ray-sensitive or radiation-sensitive resin composition used in step (1) is also conveniently referred to as a "resist composition." Furthermore, the film formed in step (1) using the actinic ray-sensitive or radiation-sensitive resin composition is typically a resist film. The film formed using the actinic ray-sensitive or radiation-sensitive resin composition is also conveniently referred to as a "resist film." Details of the actinic ray-sensitive or radiation-sensitive resin composition used in step (1) will be described later.

[0032] Step (1) is preferably a step of forming a resist film on a substrate using a resist composition.

[0033] As a method for forming a resist film on a substrate using a resist composition, for example, a method of coating the resist composition on a substrate can be mentioned. 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 pore size of the filter is not particularly limited, but may be 0.001 μm or more. The material of the filter is not particularly limited. In the case of a polymer, it is preferable to use 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 perfluoroalkoxyalkane; derivatives of the above polymers; etc., and more preferably at least one selected from the group consisting of polyolefins, polyamides, polyimides, polyamideimides, polyesters, polysulfones, cellulose, polyfluorocarbons, and derivatives thereof. In addition to resins, diatomaceous earth, glass, etc. may also be used. The filter used to filter the resist composition may be one filter, or two or more filters may be used in combination. When two or more filters are used, they may be the same filter or different filters.

[0034] The resist composition can be applied onto a substrate (e.g., silicon, silicon coated with silicon dioxide, etc.) such as those used in the manufacture of integrated circuit elements by an appropriate application method such as a spinner or coater. Spin application using a spinner is preferred. The rotation speed when spin application using a spinner is preferably 1000 to 3000 rpm (rotations per minute). After application of the resist composition, the substrate may be dried to form a resist film. If necessary, various undercoating films (inorganic film, organic film, anti-reflective film, etc.) may be formed below the resist film.

[0035] An example of a drying method is a method of drying by heating. Heating can be performed by means provided in at least one of a normal exposure machine and a developing machine, and may be performed 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 1,000 seconds, more preferably 60 to 800 seconds, and even more preferably 60 to 600 seconds.

[0036] The thickness of the resist film is not particularly limited, but is preferably 10 to 120 nm from the viewpoint of forming a finer pattern with higher precision. In particular, when EUV exposure is used, the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. Furthermore, when ArF immersion exposure is used, the thickness of the resist film is more preferably 10 to 120 nm, and even more preferably 15 to 90 nm.

[0037] A top coat may be formed on the resist film using a top coat composition. It is preferable that the top coat composition does not mix with the resist film and can be uniformly applied to the resist film. The top coat is not particularly limited, and a conventionally known top coat can be formed by a conventionally known method. For example, a top coat can be formed based on the description in paragraphs

[0072] to

[0082] of JP 2014-059543 A. For example, a top coat containing a basic compound such as that described in JP 2013-61648 A is preferably formed on the resist film. Specific examples of basic compounds that may be contained in the top coat include basic compounds that may be contained in the resist composition. It is also preferable that the top coat contain a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond.

[0038] [Step (2)] Step (2) is a step of exposing the film (resist film) formed in step (1). Examples of exposure methods include irradiating the formed resist film with actinic rays or radiation through a predetermined mask. Examples of actinic rays or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams, and preferably far ultraviolet light with a wavelength of 250 nm or less, more preferably 220 nm or less, and particularly preferably 1 to 200 nm, specifically KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ２ These include excimer laser (157 nm), EUV (13 nm), X-ray, and electron beam.

[0039] After exposure, it is preferable to bake (heat) the film before developing. Baking promotes the reaction of the exposed areas, resulting in better sensitivity and pattern shape. The heating temperature for baking 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 for baking is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. Heating can be carried out using a means provided in at least one of a conventional exposure machine and a development machine, and may be carried out using a hot plate or the like. This process is also called post-exposure baking.

[0040] [Step (3)] Step (3) is a step of developing the film exposed in step (2) with an organic processing liquid. The organic processing liquid used in step (3) contains butyl acetate and a hydrocarbon having from 9 to 12 carbon atoms. The hydrocarbon having from 9 to 12 carbon atoms contained in the organic processing liquid used in step (3) 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 nonane, decane, undecane, and dodecane, particularly preferably at least one selected from the group consisting of undecane and dodecane, and most preferably undecane. The hydrocarbon having from 9 to 12 carbon atoms may contain a structural isomer when such a structural isomer exists, such as undecane or dodecane. The hydrocarbon having from 9 to 12 carbon atoms contained in the organic processing liquid may contain only one type or two or more types.

[0041] The content of hydrocarbons having from 9 to 12 carbon atoms in the organic treatment liquid (the total amount when multiple hydrocarbons having from 9 to 12 carbon atoms are contained) is preferably from 1 to 40 mass %, more preferably from 1 to 35 mass %, even more preferably from 5 to 30 mass %, and particularly preferably from 10 to 25 mass %, based on 100 mass % of the entire organic treatment liquid.

[0042] The organic treatment liquid contains butyl acetate (n-butyl acetate). The content of butyl acetate in the organic treatment liquid is preferably 60% by mass or more and 99% by mass or less, more preferably 65% ​​by mass or more and 99% by mass or less, even more preferably 70% by mass or more and 95% by mass or less, and particularly preferably 75% by mass or more and 90% by mass or less, based on 100% by mass of the entire organic treatment liquid.

[0043] The mass ratio of butyl acetate to hydrocarbons having from 9 to 12 carbon atoms in the organic treatment liquid (butyl acetate content / hydrocarbon content having from 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.

[0044] The organic treatment liquid may contain other components in addition to butyl acetate and hydrocarbons having from 9 to 12 carbon atoms. Examples of other components include water, organic solvents other than butyl acetate and hydrocarbons having from 9 to 12 carbon atoms, surfactants, antioxidants, basic compounds, etc. The content of other components in the organic treatment liquid is preferably from 0 to 5% by mass, more preferably from 0 to 1% by mass, even more preferably from 0 to 0.5% by mass, and particularly preferably 0% by mass (i.e., no other components are contained), based on 100% by mass of the entire organic treatment liquid.

[0045] The developing method in step (3) is not particularly limited, but examples include a method in which the resist film is immersed in a tank filled with a developer (the organic processing liquid) for a certain period of time (dip method), a method in which the developer is raised on the surface of the resist film by surface tension and then left stationary for a certain period of time for development (puddle method), a method in which the developer is sprayed onto the surface of the resist film (spray method), and a method in which the developer is continuously dispensed onto a substrate rotating at a constant speed while a developer dispense nozzle is scanned at a constant speed (dynamic dispense method). Furthermore, after the development step, a step of stopping development while replacing the solvent with another solvent may be carried out. The development time is not particularly limited as long as it is long enough to sufficiently dissolve the resin in the area to be removed, and is preferably 10 to 300 seconds, more preferably 20 to 120 seconds. The temperature of the developer is not particularly limited, but is preferably 0 to 50°C, more preferably 15 to 35°C.

[0046] By carrying out step (3), a resist pattern (also simply referred to as a "pattern") is formed. After carrying out step (3), rinsing may be carried out. Rinsing may be carried out using the organic treatment liquid described above, or a rinse liquid other than the organic treatment liquid described above. The rinse liquid other than the organic treatment liquid described above is not particularly limited as long as it does not dissolve the pattern, and a solution containing a general organic solvent may be used. The rinse liquid other than the organic treatment liquid described above 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.

[0047] The rinsing method is not particularly limited, and examples thereof include a method in which a rinse liquid is continuously discharged onto a substrate rotating at a constant speed (spin coating method), a method in which a substrate is immersed in a tank filled with the rinse liquid for a certain period of time (dip method), and a method in which a rinse liquid is sprayed onto the surface of the substrate (spray method).

[0048] The pattern formation method of the present invention may also include a heating step (post-bake) after step (3). This step removes the developer and rinse solution remaining between and within the pattern. This step also has the effect of annealing 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 10 seconds to 3 minutes (preferably 30 to 120 seconds).

[0049] Alternatively, the substrate may be etched using the formed pattern as a mask. That is, the substrate (or the underlayer film and the substrate) may be processed using the pattern formed in step (3) as a mask to form a pattern on the substrate. The method for processing the substrate (or the underlayer film and the substrate) is not particularly limited, but a method of forming a pattern on the substrate by dry etching the substrate (or the underlayer film and the substrate) using the pattern formed in step (3) as a mask is preferred. The dry etching is not particularly limited, but oxygen plasma etching is preferred.

[0050] The organic processing liquid, resist composition, and other various materials (e.g., solvent, rinse solution, anti-reflective coating composition, top coat composition, etc.) used in the pattern formation method of the present invention preferably do not contain impurities such as metals. The content of impurities contained in these materials is preferably 1 mass ppm (parts per million) or less, more preferably 10 mass ppb (parts per billion) or less, even more preferably 100 mass ppt (parts per trillion) or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. The lower limit of the impurity content is not particularly limited, and may be 0 mass ppt or more. Here, examples of metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn.

[0051] Examples of methods for removing impurities such as metals from various materials include filtration using a filter. Details of filtration using a filter are described in paragraph

[0321] of WO 2020 / 004306.

[0052] Methods for reducing impurities such as metals contained in various materials include, for example, selecting raw materials with a low metal content as raw materials for the various materials, filtering the raw materials for the various materials, and performing distillation under conditions that minimize contamination as much as possible, for example by lining the inside of the apparatus with Teflon (registered trademark).

[0053] In addition to filter filtration, impurities may be removed using an adsorbent, or a combination of filter filtration and an adsorbent may be used. Known adsorbents can be used as the adsorbent, including inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon. In order to reduce impurities such as metals contained in the various materials, it is necessary to prevent the incorporation of metal impurities during the manufacturing process. Whether metal impurities have been sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of metal components contained in the cleaning solution used to clean the manufacturing equipment. The content of metal components contained in the used cleaning solution is preferably 100 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, and a content of 0 ppt by mass or more is preferred.

[0054] A conductive compound may be added to the organic processing solution and rinse solution to prevent breakdown of the chemical solution piping and various parts (filters, O-rings, tubes, etc.) due to static charging and subsequent electrostatic discharge. The conductive compound is not particularly limited, but examples include methanol. The amount added is not particularly limited, but in terms of maintaining favorable development characteristics or rinsing characteristics, it is preferably 10% by mass or less, more preferably 5% by mass or less. The lower limit of the amount of the conductive compound added is not particularly limited, and may be 0.01% by mass or more. For the chemical solution piping, for example, stainless steel (SUS), or various piping coated with antistatically treated polyethylene, polypropylene, or fluororesin (such as polytetrafluoroethylene or perfluoroalkoxy resin), can be used. Similarly, for the filters and O-rings, antistatically treated polyethylene, polypropylene, or fluororesin (such as polytetrafluoroethylene or perfluoroalkoxy resin), can be used.

[0055] [Actinic ray- or radiation-sensitive resin composition] The actinic ray- or radiation-sensitive resin composition used in step (1) will be described. The actinic ray- or radiation-sensitive resin composition (resist composition) used in step (1) contains an acid-decomposable resin (P) and a photoacid generator. The acid-decomposable resin (P) and the photoacid generator may be different compounds or the same compound.

[0056] The resist composition may be a positive resist composition or a negative resist composition, but is preferably a negative resist composition. Furthermore, the resist composition is preferably a resist composition for organic solvent development. The resist composition may be a chemically amplified resist composition or a non-chemically amplified resist composition, but is preferably a chemically amplified resist composition.

[0057] [Acid-Decomposable Resin (P)] The resist composition contains an acid-decomposable resin (P) (also simply referred to as "resin (P)"). The resin (P) contains at least four types of repeating units, one of which is a repeating unit (U1) represented by formula (I) (also simply referred to as "repeating unit (U1)") and at least one of which is a repeating unit (U2) represented by formula (II) (also simply referred to as "repeating unit (U2)").

[0058]

[0059] In formula (II), R １ represents a hydrogen atom, a halogen atom or an alkyl group, R ２ represents a group that is eliminated by the action of an acid.

[0060] The content of the repeating unit (U1) in the resin (P) is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and particularly preferably more than 30 mol%, based on the total repeating units in the resin (P). The content of the repeating unit (U1) in the resin (P) is preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less, based on the total repeating units in the resin (P).

[0061] R in formula (II) １ The halogen atom represented by R is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. １ The alkyl group represented by may be either linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 7, and particularly preferably 1 to 4. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The alkyl group may have a substituent. The substituent is not particularly limited, and examples thereof include the substituent T described above. R １ preferably represents a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group.

[0062] R in formula (II) ２ represents a group that is eliminated by the action of an acid. ２ Examples of the group that is eliminated by the action of an acid, which is represented by the formula (Y1), (Y3) or (Y4), are groups represented by the formula (R ２ represents a group represented by formula (Y1). Formula (Y1): -C(Rx １ ) (Rx ２ ) (Rx ３ ) Formula (Y3): -C(R ３６ ) (R ３７ ) (OR ３８ ) Formula (Y4): -C(Rn)(H)(Ar)

[0063] In formula (Y1), Rx １ ~Rx ３ Rx each independently represents an alkyl group (which may be linear or branched), a cycloalkyl group (which may be monocyclic or polycyclic), an alkenyl group (which may be linear or branched), or an aryl group (which may be monocyclic or polycyclic). １ ~Rx ３ When all of Rx are alkyl groups (which may be linear or branched), １ ~Rx ３ At least two of Rx are preferably methyl groups. １ ~Rx ３each independently preferably represents a linear or branched alkyl group, and Rx １ ~Rx ３ More preferably, Rx each independently represents a linear alkyl group. １ ~Rx ３ may be bonded to form a monocyclic or polycyclic ring. １ ~Rx ３ The alkyl group represented by is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. １ ~Rx ３ The cycloalkyl group represented by Rx may be a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or may be a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. １ ~Rx ３ The aryl group represented by is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. １ ~Rx ３ The alkenyl group represented by Rx is preferably an alkenyl group having 2 to 5 carbon atoms, and more preferably a vinyl group. １ ~Rx ３ The ring formed by combining the two is preferably a cycloalkyl group. １ ~Rx ３ The cycloalkyl group formed by combining the two 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. １ ~Rx ３ The cycloalkyl group formed by combining the above two is preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms. １ ~Rx ３In the cycloalkyl group formed by bonding these two, one or more of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. In addition, in the cycloalkyl group, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. The group represented by formula (Y1) can be, for example, Rx １ is a methyl group or an ethyl group, and Rx ２ and Rx ３ and Rx are preferably bonded to form the above-mentioned cycloalkyl group. When the actinic ray-sensitive or radiation-sensitive resin composition is, for example, a resist composition for EUV exposure, １ ~Rx ３ an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, and Rx １ ~Rx ３ The ring formed by bonding these two groups preferably further has a fluorine atom or an iodine atom as a substituent.

[0064] In formula (Y3), R ３６ ~R ３８ R each independently represents a hydrogen atom or a monovalent organic group. ３７ and R ３８ may be bonded to each other to form a ring. Examples of the monovalent organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. ３６ is also preferably a hydrogen atom. The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a heteroatom such as an oxygen atom and / or a group containing a heteroatom such as a carbonyl group. For example, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, one or more methylene groups may be replaced with a heteroatom such as an oxygen atom and / or a group containing a heteroatom such as a carbonyl group. R ３８ may bond with another substituent on the main chain of the repeating unit to form a ring. ３８The group formed by bonding together R and another substituent on the main chain of the repeating unit is preferably an alkylene group such as a methylene group. ３６ ~R ３８ and a monovalent organic group represented by R ３７ and R ３８ It is also preferable that the ring formed by bonding these groups together further has a fluorine atom or an iodine atom as a substituent.

[0065] Formula (Y3) is preferably a group represented by the following formula (Y3-1).

[0066]

[0067] Here, L Ｙ１ and L Ｙ２ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group formed by combining these (for example, a group formed by combining an alkyl group and an aryl group). Ｙ１ represents a single bond or a divalent linking group. Ｙ１ represents an alkyl group which may contain a heteroatom, a cycloalkyl group which may contain a heteroatom, an aryl group which may contain a heteroatom, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group, or a group which combines these (for example, a group which combines an alkyl group and a cycloalkyl group). In the alkyl group and the cycloalkyl group, for example, one of the methylene groups may be replaced with a heteroatom such as an oxygen atom, or a group which contains a heteroatom such as a carbonyl group. Ｙ１ and L Ｙ２ Preferably, one of Q is a hydrogen atom, and the other is an alkyl group, a cycloalkyl group, an aryl group, or a group in which an alkylene group and an aryl group are combined. Ｙ１ , M Ｙ１ , and L Ｙ１ At least two of the groups may be bonded to form a ring (preferably a 5- or 6-membered ring). Ｙ２is preferably a secondary or tertiary alkyl group, and more preferably a tertiary alkyl group. Examples of secondary alkyl groups include an isopropyl group, a cyclohexyl group, and a norbornyl group, and examples of tertiary alkyl groups include a tert-butyl group and an adamantane group. In these embodiments, the Tg (glass transition temperature) and activation energy are high, thereby ensuring film strength and suppressing fogging. In formula (Y3-1), * represents a bonding position.

[0068] In formula (Y4), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may be bonded to each other to form a non-aromatic ring. Ar is preferably an aryl group.

[0069] The repeating unit (U2) is R ２ The resin (P) preferably has an acid-decomposable group-containing repeating unit, and thus has an acid-decomposable group-containing repeating unit. The resin (P) preferably has an acid-decomposable group-containing repeating unit, and the polarity of the resin (P) is increased by the action of an acid, thereby decreasing the solubility of the resin (P) in organic solvents.

[0070] Specific examples of the monomer corresponding to the repeating unit (U2) (monomer from which the repeating unit (U2) is obtained by polymerization reaction) are shown below, but are not limited to these.

[0071]

[0072] As used herein, the term "monomer corresponding to a repeating unit" refers to a repeating unit whose structure is obtained when the monomer is polymerized (when the polymerizable group of the monomer is polymerized). When a repeating unit contained in a polymer is described as a corresponding monomer, the repeating unit does not necessarily have to have been obtained using the corresponding monomer (for example, the repeating unit may be obtained by modifying the structure through a chemical reaction after performing a polymerization reaction using another monomer). Examples of the polymerizable group of the monomer include groups containing a carbon-carbon double bond, such as a vinyl group, an allyl group, an acryloyl group, and a methacryloyl group. Examples of polymerization reactions include addition polymerization reactions. Examples of repeating units and monomers corresponding to the repeating unit include a repeating unit represented by the following formula (RM-1) and a corresponding monomer represented by the following formula (RM-2). In the above relationship (i.e., when the monomer corresponds to the repeating unit), the repeating unit is also referred to as a "repeating unit derived from a monomer." For example, the repeating unit represented by the following formula (RM-1) is a repeating unit derived from a monomer represented by the following formula (RM-2).

[0073]

[0074] In formulas (RM-1) and (RM-2), R １００ represents a hydrogen atom or a substituent. １０１ represents a substituent. １ and ※ ２ represents the bond position.

[0075] The content of the repeating unit (U2) in the resin (P) is preferably 30 mol% or more, more preferably 40 mol% or more, even more preferably 45 mol% or more, and particularly preferably more than 50 mol%, based on the total repeating units in the resin (P). The content of the repeating unit (U2) in the resin (P) is preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less, based on the total repeating units in the resin (P). The repeating unit (U2) contained in the resin (P) may be one type or two or more types. When the repeating unit (U2) contained in the resin (P) is two or more types, it is preferable that the total content thereof is within the above-mentioned preferred content range.

[0076] The resin (P) preferably contains a repeating unit (also referred to as "repeating unit (U3)") that does not fall under either the repeating unit (U1) or the repeating unit (U2), and more preferably contains two or more types of repeating unit (U3). The repeating unit (U3) is not particularly limited as long as it does not fall under either the repeating unit (U1) or the repeating unit (U2).

[0077] (Repeating unit having an acid group (repeating unit (U3a))) The repeating unit (U3) may be a repeating unit having an acid group. A repeating unit having an acid group that does not fall into either the repeating unit (U1) or the repeating unit (U2) is also referred to as a "repeating unit (U3a)". Preferred examples of the acid group contained in the repeating unit (U3a) include a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, and an isopropanol group. The hexafluoroisopropanol group may have one or more fluorine atoms (preferably one or two) substituted with a group other than a fluorine atom (such as an alkoxycarbonyl group). Examples of the acid group include the -C(CF) formed in this way. ３ )(OH)—CF ２ In addition, one or more fluorine atoms are substituted with a group other than a fluorine atom to form -C(CF ３ )(OH)—CF ２- may form a ring containing the same. The repeating unit having an acid group is preferably a repeating unit different from the repeating unit having an acid-decomposable group. The repeating unit having an acid group may have a fluorine atom or an iodine atom. Specific examples of the repeating unit having an acid group include the repeating units described in

[0088] to

[0089] and

[0103] to

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

[0078] The repeating unit having an acid group is preferably a repeating unit having a phenolic hydroxyl group.

[0079] The repeating unit having an acid group may be a repeating unit represented by the following formula (Pa1).

[0080]

[0081] In formula (Pa1), R ａ１ and R ａ２ each independently represents a hydrogen atom or a substituent. ａ１ represents a single bond or a divalent linking group. ａ１ represents an aromatic ring group. ａ１ And, R ａ２ or L ａ１ may be bonded to by a single bond or via a linking group. Ｘ represents a substituent other than a hydroxy group. n represents an integer of 1 or more and 9 or less. m represents an integer of 0 or more and 8 or less.

[0082] R in formula (Pa1) ａ１ and R ａ２ R each independently represents a hydrogen atom or a substituent. ａ１ and R ａ２ The substituent represented by is not particularly limited, but is preferably an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. ａ１ and R ａ２The alkyl group represented by may be either linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The alkyl group may have a substituent. R ａ１ and R ａ２ The number of carbon atoms in the cycloalkyl group represented by is not particularly limited, but is preferably 3 to 20, and more preferably 5 to 15. The cycloalkyl group may be a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. The cycloalkyl group may have a substituent. R ａ１ and R ａ２ Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom or an iodine atom is preferred. ａ１ and R ａ２ The alkyl group contained in the alkoxycarbonyl group represented by the formula (I) may be either linear or branched. The number of carbon atoms in the alkyl group contained in the alkoxycarbonyl group is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 3. The alkoxycarbonyl group may have a substituent.

[0083] L in formula (Pa1) ａ１ represents a single bond or a divalent linking group. ａ１ The divalent linking group represented by is not particularly limited, but examples thereof include —COO—, —CONR ａ３ -, an alkylene group, or a group formed by combining two or more of these groups. ａ３ represents a hydrogen atom or an alkyl group. The alkylene group is not particularly limited, but is preferably an alkylene group having 1 to 8 carbon atoms, such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, or an octylene group. The alkylene group may have a substituent. R ａ３When represents an alkyl group, examples of the alkyl group include alkyl groups having 20 or less carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, and a dodecyl group, and alkyl groups having 8 or less carbon atoms are preferred.

[0084] Ar in formula (Pa1) ａ１ represents an aromatic ring group, specifically an (m+n+1)-valent aromatic ring group. ａ１ The aromatic ring group represented by may be an aromatic hydrocarbon group or an aromatic heterocyclic group. The aromatic hydrocarbon group is preferably a group containing an aromatic hydrocarbon having 6 to 18 carbon atoms, such as benzene, naphthalene, anthracene, or naphthacene. The aromatic heterocyclic group preferably contains at least one heteroatom selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom as a ring member. The aromatic heterocyclic group is preferably a group containing an aromatic heterocycle having 4 to 20 ring atoms, such as thiophene, furan, pyridine, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, or thiazole.

[0085] Ar ａ１ And, R ａ２ or L ａ１ may be bonded to by a single bond or via a linking group. Examples of the linking group include -O-, -S-, -CO-, -CO ２ -, -SO-, -SO ２ -, alkylene groups (preferably having 1 to 5 carbon atoms), alkenylene groups (preferably having 2 to 5 carbon atoms), and groups formed by combining two or more of these. The alkylene groups and alkenylene groups may have a substituent.

[0086] R in formula (Pa1) Ｘ represents a substituent other than a hydroxy group. Ｘ Examples of the substituent represented by R include a carboxyl group, a sulfo group, a cyano group, a halogen atom, a hydrocarbon group, an amino group, a nitro group, and a group formed by combining two or more of these. ＸExamples of the hydrocarbon group represented by R include an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 5 to 15 carbon atoms), and an alkenyl group (preferably having 2 to 10 carbon atoms). Ｘ The hydrocarbon group represented by may have a substituent. Ｘ The hydrocarbon group represented by is -CH ２ When it contains -, -CH ２ At least one of - is -O-, -CO-, -S- and -SO ２ - may be replaced with at least one selected from the group consisting of Ｘ The substituent represented by the formula (I) preferably has a halogen atom. The halogen atom is preferably a fluorine atom or an iodine atom, and more preferably an iodine atom.

[0087] In formula (Pa1), n ​​represents an integer of 1 or more and 9 or less, preferably an integer of 1 or more and 5 or less, and more preferably an integer of 1 or more and 4 or less.

[0088] In formula (Pa1), m represents an integer of 0 or more and 8 or less, preferably an integer of 0 or more and 4 or less, and more preferably an integer of 0 or more and 3 or less.

[0089] The repeating unit having an acid group may be a repeating unit represented by the following formula (Pa2).

[0090]

[0091] In formula (Pa2), R ａ４ represents a hydrogen atom or an alkyl group. ａ２ represents a single bond or —COO—. Ｘ１ represents a halogen atom or a hydrocarbon group. n1 represents an integer of 1 or more and 5 or less. m1 represents an integer of 0 or more and 4 or less. r represents an integer of 0 or more and 3 or less.

[0092] R in formula (Pa2) ａ４ represents a hydrogen atom or an alkyl group. ａ４The alkyl group represented by may be either linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The alkyl group may have a substituent.

[0093] L in formula (Pa2) ａ２ represents a single bond or —COO—, and preferably represents a single bond.

[0094] In formula (Pa2), r represents an integer of 0 or more and 3 or less, preferably an integer of 0 or more and 2 or less, more preferably 0 or 1, and even more preferably 0. In formula (Pa2), the aromatic ring is benzene when r represents 0, naphthalene when r represents 1, anthracene when r represents 2, and naphthacene when r represents 3.

[0095] R in formula (Pa2) Ｘ１ represents a halogen atom or a hydrocarbon group. Ｘ１ The halogen atom represented by R is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, more preferably a fluorine atom or an iodine atom, and even more preferably an iodine atom. Ｘ１ Examples of the hydrocarbon group represented by R include an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 5 to 15 carbon atoms), and an alkenyl group (preferably having 2 to 10 carbon atoms). Ｘ１ The hydrocarbon group represented by may have a substituent. Ｘ１ The hydrocarbon group represented by is -CH ２ When it contains -, -CH ２ At least one of - is -O-, -CO-, -S- and -SO ２ - may be replaced with at least one selected from the group consisting of Ｘ１ The hydrocarbon group represented by the formula (I) preferably contains a halogen atom. The halogen atom is preferably a fluorine atom or an iodine atom, and more preferably an iodine atom.

[0096] In formula (Pa2), n1 represents an integer of 1 or more and 5 or less, and preferably represents an integer of 1 or more and 4 or less.

[0097] In formula (Pa2), m1 represents an integer of 0 or more and 4 or less, and preferably represents an integer of 0 or more and 3 or less.

[0098] Specific examples of the monomer corresponding to the repeating unit (U3a) (monomer from which the repeating unit (U3a) is obtained by polymerization reaction) are shown below, but are not limited to these.

[0099]

[0100] When the resin (P) contains the repeating unit (U3a), the content of the repeating unit (U3a) may be 1 mol% or more, 3 mol% or more, or 5 mol% or more, based on the total repeating units in the resin (P). Furthermore, the content of the repeating unit (U3a) may be 40 mol% or less, 35 mol% or less, or 30 mol% or less, based on the total repeating units in the resin (P). When the resin (P) contains the repeating unit (U3a), the repeating unit (U3a) may be one type, or two or more types. When the resin (P) contains two or more types of repeating units (U3a), the total content thereof is preferably within the above range.

[0101] (Repeating unit having at least one selected from the group consisting of a lactone group, a sultone group, a carbonate group, a sulfonyl group, and a saturated hydrocarbon group having a hydroxy group (repeating unit (U3b))) The repeating unit (U3) may be a repeating unit having at least one selected from the group consisting of a lactone group, a sultone group, a carbonate group, a sulfonyl group, and a saturated hydrocarbon group having a hydroxy group. A repeating unit that does not fall under either the repeating unit (U1) or the repeating unit (U2) and has at least one selected from the group consisting of a lactone group, a sultone group, a carbonate group, a sulfonyl group, and a saturated hydrocarbon group having a hydroxy group is also referred to as a "repeating unit (U3b)."

[0102] The lactone group or sultone group may have a lactone structure or a sultone structure. The lactone structure or sultone structure is preferably a 5- to 7-membered lactone structure or a 5- to 7-membered sultone structure. Among these, a 5- to 7-membered lactone structure to which another ring structure is fused in the form of a bicyclo or spiro structure, or a 5- to 7-membered sultone structure to which another ring structure is fused in the form of a bicyclo or spiro structure, is more preferred. Examples of lactone groups include lactone groups obtained by removing one or more hydrogen atoms from ring atoms of a lactone structure represented by any of the following formulae (LC1-1) to (LC1-22). The lactone group is preferably a polycyclic lactone group. Examples of sultone groups include sultone groups obtained by removing one or more hydrogen atoms from ring atoms of a sultone structure represented by any of the following formulae (SL1-1) to (SL1-3). The sultone group is preferably a polycyclic sultone group. Examples of the carbonate group include carbonate groups obtained by removing one or more hydrogen atoms from ring atoms of a cyclic carbonate ester structure represented by any one of the following formulae (CC1-1) and (CC1-2): The lactone group, sultone group, and carbonate group may have a substituent.

[0103] R in the following structural formula Ｌ represents a substituent. Ｌ If there are multiple R Ｌ may be the same or different. Ｌ Examples of R include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 10 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a carboxyl group, a halogen atom, a cyano group, and an acid-decomposable group. e1 represents an integer of 0 to 4. When multiple e1s are present, the multiple e1s may be the same or different. When e1 is 2 or more, the multiple R Ｌ may be the same or different, and multiple R Ｌ They may be bonded to each other to form a ring.

[0104]

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

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

[0127] to

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

[0107] The saturated hydrocarbon group having a hydroxy group is preferably a saturated hydrocarbon group having 3 to 20 carbon atoms and having a hydroxy group, and more preferably a saturated hydrocarbon group having 4 to 15 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic, but is preferably a cyclic (alicyclic) group. When the saturated hydrocarbon group is linear or branched, it may contain a heteroatom such as an oxygen atom or a group containing a heteroatom such as a carbonyl group in the chain. When the saturated hydrocarbon group is an alicyclic group, at least one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom or a group containing a heteroatom such as a carbonyl group. The saturated hydrocarbon group having a hydroxy group is preferably an alicyclic group having a hydroxy group, and more preferably an alicyclic group having two or more hydroxy groups.

[0108] Examples of the repeating unit (U3b) include a repeating unit represented by the following formula (AI-2).

[0109]

[0110] In formula (AI-2), Rb ０ represents a hydrogen atom, a halogen atom or an alkyl group. ０ The alkyl group represented by Rb may have a substituent. ０ The substituents that the alkyl group represented by Rb may have are preferably a hydroxyl group and a halogen atom. ０Examples of the halogen atom represented by Rb include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. ０ Preferably, Ab represents a hydrogen atom or a methyl group. Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent linking group formed by combining these. Among these, Ab is preferably a single bond or -Ab １ -CO ２ A linking group represented by - is preferred. １ is a linear or branched alkylene group, or a monocyclic or polycyclic cycloalkylene group, and is preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group, or a norbornylene group. V is a lactone group, a sultone group, a carbonate group, a group containing a sulfonyl group, or a saturated hydrocarbon group having a hydroxy group.

[0111] The sulfonyl group-containing group represented by V is preferably an aliphatic group containing a sulfonyl group, more preferably a group in which one or more methylene groups in an alkyl group or cycloalkyl group are replaced with sulfonyl groups, and even more preferably a group in which one or more methylene groups in a cycloalkyl group are replaced with sulfonyl groups. The number of carbon atoms in the sulfonyl group-containing aliphatic group is not particularly limited, but is preferably 1 to 20, more preferably 1 to 10. The sulfonyl group-containing group may contain one or more heteroatoms other than the sulfonyl group. Furthermore, the sulfonyl group-containing group may have a substituent. R ｍ４ Examples of the group containing a sulfonyl group represented by the formula (SN1-1) to (SN1-5) include groups obtained by removing one or more hydrogen atoms from the structure represented by the formula (SN1-1) to (SN1-5). Ｌ represents a substituent. Ｌ If there are multiple R Ｌ may be the same or different. ＬExamples of R include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 10 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a halogen atom, and a cyano group. e1 represents an integer of 0 to 4. When e1 is 2 or more, multiple R Ｌ may be the same or different, and multiple R Ｌ They may be bonded to each other to form a ring.

[0112]

[0113] Specific examples of the monomer corresponding to the repeating unit (U3b) (monomer from which the repeating unit (U3b) is obtained by polymerization reaction) are shown below, but are not limited to these.

[0114]

[0115] When the resin (P) contains the repeating unit (U3b), the content of the repeating unit (U3b) may be 1 mol% or more, 3 mol% or more, or 5 mol% or more, based on the total repeating units in the resin (P). Furthermore, the content of the repeating unit (U3b) may be 40 mol% or less, 35 mol% or less, or 30 mol% or less, based on the total repeating units in the resin (P). When the resin (P) contains the repeating unit (U3b), the repeating unit (U3b) may be one type, or two or more types. When the resin (P) contains two or more types of repeating units (U3b), the total content thereof is preferably within the above range.

[0116] (Repeating unit having a group that leaves by the action of acid (repeating unit (U3c))) The repeating unit (U3) may be a repeating unit having a group that leaves by the action of acid. A repeating unit that does not fall into either the repeating unit (U1) or the repeating unit (U2) and has a group that leaves by the action of acid is also referred to as a "repeating unit (U3c)". The repeating unit (U3c) is preferably a repeating unit having an acid-decomposable group. The acid-decomposable group is a group that decomposes under the action of acid to increase its polarity. The acid-decomposable group preferably has a structure in which a polar group is protected by a group that leaves under the action of acid (leaving group). The acid-decomposable group is preferably a group that decomposes under the action of acid to generate a polar group. Examples of the polar group include a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group, a sulfonic acid group, a phosphoric acid group, a sulfonamide group, a sulfonylimide group, a (alkylsulfonyl) (alkylcarbonyl) methylene group, a (alkylsulfonyl) (alkylcarbonyl) imide group, a bis(alkylcarbonyl) methylene group, a bis(alkylcarbonyl) imide group, a bis(alkylsulfonyl) methylene group, a bis(alkylsulfonyl) imide group, a tris(alkylcarbonyl) methylene group, and a tris(alkylsulfonyl) methylene group, and an acidic group such as an alcoholic hydroxyl group. Among these, the polar group is preferably a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group.

[0117] Examples of the group that is eliminated by the action of an acid include the groups represented by the above formulae (Y1) to (Y4).

[0118] The group that is eliminated by the action of an acid may also be a 2-cyclopentenyl group having a substituent (such as an alkyl group), such as a 3-methyl-2-cyclopentenyl group, or a cyclohexyl group having a substituent (such as an alkyl group), such as a 1,1,4,4-tetramethylcyclohexyl group.

[0119] The repeating unit (U3c) may be at least one selected from the group consisting of a repeating unit represented by formula (M-1), a repeating unit represented by formula (M-2), a repeating unit represented by formula (M-3), and a repeating unit represented by formula (M-4). The repeating unit represented by formula (M-1), a repeating unit represented by formula (M-2), a repeating unit represented by formula (M-3), and a repeating unit represented by formula (M-4) are repeating units having a group that is eliminated by the action of an acid.

[0120]

[0121] In formula (M-1), R １１ , R １２ and R １３ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. Ｍ１ represents a divalent linking group. １４ , R １５ and R １６ R each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. １４ , R １５ and R １６ In formula (M-2), two of R may be bonded to form a ring. ２１ , R ２２ and R ２３ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. Ｍ２ represents a divalent linking group. ２４ , R ２５ and R ２６ R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. ２５ and R ２６ may be bonded to form a ring. Ｍ２ The aromatic group contained in R ２２ or R ２４ In formula (M-3), R ３１ , R ３２ and R ３３each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. Ｍ３ represents a divalent linking group. ３４ and R ３５ R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. ３６ represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. ３５ and R ３６ may be bonded to form a ring. ４１ , R ４２ and R ４３ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. Ｍ４ represents a divalent linking group. ４４ , R ４５ and R ４６ R each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. ４４ , R ４５ and R ４６ Two of these may be bonded to form a ring.

[0122] The repeating unit represented by formula (M-1) will be described. １１ , R １２ and R １３ The alkyl group represented by R may be either linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 3. １１ , R １２ and R １３The cycloalkyl group represented by the formula (I) 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. In the cycloalkyl group, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group having a heteroatom such as a carbonyl group, or a vinylidene group. In addition, in the cycloalkyl group, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. １１ , R １２ and R １３ Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom or an iodine atom is preferred. １１ , R １２ and R １３ The alkyl group contained in the alkoxycarbonyl group represented by the formula (I) may be either linear or branched. The number of carbon atoms in the alkyl group contained in the alkoxycarbonyl group is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 3.

[0123] L Ｍ１ represents a divalent linking group. Ｍ１ as an aromatic group, —CO—, —O—, —S—, —SO—, —SO ２ -, alkylene groups (for example, linear or branched alkylene groups having 1 to 10 carbon atoms), cycloalkylene groups (for example, monocyclic or polycyclic cycloalkylene groups having 3 to 20 carbon atoms), alkenylene groups (for example, linear or branched alkylene groups having 2 to 10 carbon atoms), and groups in which a plurality of these groups are linked together. Ｍ１ A preferred embodiment of the formula is L Ｍ１ In this embodiment, L contains an aromatic group. The aromatic group may be an aromatic hydrocarbon group or an aromatic heterocyclic group. Ｍ１ When contains an aromatic group and another divalent group, the other divalent group is preferably located closer to the main chain of the resin (P) than the aromatic group.

[0124] L Ｍ１When contains an aromatic hydrocarbon group, the aromatic hydrocarbon group may be either monocyclic or polycyclic. The number of carbon atoms in the aromatic hydrocarbon group is not particularly limited, but is, for example, preferably 6 to 20, more preferably 6 to 14. The aromatic hydrocarbon group is preferably a phenylene group or a naphthylene group, and more preferably a phenylene group. The aromatic hydrocarbon group may also be a group obtained by removing two hydrogen atoms from a fused ring compound having a structure in which an aromatic hydrocarbon (e.g., benzene, naphthalene, etc.) is condensed with a cycloalkane (e.g., cyclopentane, cyclohexane, etc.).

[0125] L Ｍ１When the aromatic heterocyclic group contains an aromatic heterocyclic group, the aromatic heterocyclic group may be either monocyclic or polycyclic. The aromatic heterocyclic group preferably contains at least one heteroatom selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom as a ring member. The number of carbon atoms in the aromatic heterocyclic group is not particularly limited, but is preferably, for example, 2 to 18, more preferably 3 to 12, and even more preferably 4 to 12. The number of ring atoms in the aromatic heterocyclic group is not particularly limited, but is, for example, preferably 5 to 20, and more preferably 6 to 15. Examples of aromatic heterocyclic groups include groups obtained by removing two hydrogen atoms from five-membered aromatic heterocyclic compounds such as pyrrole, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, triazole, thiophene, and furan, or six-membered aromatic heterocyclic compounds such as pyridine, pyrazine, pyrimidine, pyridazine, triazine, thiazine, and oxazine. The aromatic heterocyclic group may also be a group obtained by removing two hydrogen atoms from a fused ring compound (e.g., indole, quinoline, isoquinoline, etc.) having a structure in which the five-membered aromatic heterocyclic compound or the six-membered aromatic heterocyclic compound is condensed with at least one selected from the group consisting of the five-membered aromatic heterocyclic compound, the six-membered aromatic heterocyclic compound, aromatic hydrocarbons (e.g., benzene, naphthalene, etc.), cycloalkanes (e.g., cyclopentane, cyclohexane, etc.), and non-aromatic heterocyclic compounds (e.g., five-membered non-aromatic heterocyclic compounds such as pyrrolidine, pyrroline, 2-oxazolidone, tetrahydrofuran, tetrahydrothiophene, and six-membered non-aromatic heterocyclic compounds such as morpholine, piperidine, piperazine, tetrahydropyran, etc.).

[0126] R １４ , R １５ and R １６ The alkyl group represented by R may be either linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 3. １４ , R １５ and R １６ In the alkyl group represented by the formula (I), the methylene group may be substituted with at least one of —CO— and —O—. １４, R １５ and R １６ The cycloalkyl group represented by the formula (R) may be a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or may be a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. １４ , R １５ and R １６ The number of carbon atoms in the aryl group represented by R is not particularly limited, but is preferably 6 to 20, and more preferably 6 to 14. １４ , R １５ and R １６ The aryl group represented by R is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. １４ , R １５ and R １６ The aralkyl group represented by the formula (I) is the same as the above-mentioned R １４ , R １５ and R １６ One hydrogen atom in the alkyl group represented by the formula １４ , R １５ and R １６ Preferred are groups substituted with an aryl group (preferably a phenyl group) represented by the following formula: and examples thereof include a benzyl group. １４ , R １５ and R １６ The alkenyl group represented by the formula (I) may be either linear or branched. The number of carbon atoms in the alkenyl group is not particularly limited, but is preferably 2 to 5, and more preferably 2 to 3. The alkenyl group is preferably a vinyl group.

[0127] R １４ , R １５ and R １６ Two of R may be bonded to form a ring. １４ , R １５ and R １６The ring formed by bonding two of these is preferably a cycloalkyl ring. The cycloalkane ring may be a monocyclic cycloalkane ring or a polycyclic cycloalkane ring. The cycloalkane ring is preferably a monocyclic cycloalkane ring having 5 to 6 carbon atoms. In the cycloalkane ring, one or more of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group having a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

[0128] Each of the above groups in formula (M-1) may have a substituent, and examples of the substituent include the above-mentioned substituent T.

[0129] The repeating unit represented by formula (M-2) will be described. ２１ , R ２２ and R ２３ The explanation, specific examples and preferred ranges of R in the above formula (M-1) are １１ , R １２ and R １３ It is the same as L Ｍ２ The explanation, specific examples and preferred ranges of L in the above formula (M-1) Ｍ１ It is the same as R ２４ , R ２５ and R ２６ The explanation, specific examples and preferred ranges of the alkyl group, cycloalkyl group, aryl group, aralkyl group and alkenyl group represented by the formula (M-1) are as follows: １４ , R １５ and R １６ It is the same as R ２５ and R ２６ may be bonded to form a ring. ２５ and R ２６ The ring formed by bonding of L is preferably a non-aromatic ring, more preferably a non-aromatic ring having 5 to 8 ring atoms. Ｍ２ The aromatic group contained in R ２２ or R ２４ may be bonded to form a ring. Ｍ２ The aromatic group contained in R ２２ or R ２４The ring formed by bonding is preferably a non-aromatic ring, more preferably a non-aromatic ring having 5 to 8 ring atoms.

[0130] Each of the above groups in formula (M-2) may have a substituent, and examples of the substituent include the above-mentioned substituent T.

[0131] The repeating unit represented by formula (M-3) will be described. ３１ , R ３２ and R ３３ The explanation, specific examples and preferred ranges of R in the above formula (M-1) are １１ , R １２ and R １３ It is the same as L Ｍ３ The explanation, specific examples and preferred ranges of L in the above formula (M-1) Ｍ１ It is the same as R ３４ , R ３５ and R ３６ The explanation, specific examples and preferred ranges of the alkyl group, cycloalkyl group, aryl group, aralkyl group and alkenyl group represented by the formula (M-1) are as follows: １４ , R １５ and R １６ It is the same as R ３５ and R ３６ may be bonded to form a ring. ３５ and R ３６ The ring formed by bonding is preferably a non-aromatic ring, more preferably a non-aromatic ring having 5 to 8 ring atoms.

[0132] Each of the above groups in formula (M-3) may have a substituent, and examples of the substituent include the above-mentioned substituent T.

[0133] The repeating unit represented by formula (M-4) will be described. ４１ , R ４２ and R ４３ The explanation, specific examples and preferred ranges of R in the above formula (M-1) are １１ , R １２ and R １３ It is the same as L Ｍ４The explanation, specific examples and preferred ranges of L in the above formula (M-1) Ｍ１ It is the same as R ４４ , R ４５ and R ４６ The explanation, specific examples and preferred ranges of the alkyl group, cycloalkyl group, aryl group, aralkyl group and alkenyl group represented by the formula (M-1) are as follows: １４ , R １５ and R １６ It is the same as R ４４ , R ４５ and R ４６ Two of R may be bonded to form a ring. ４４ , R ４５ and R ４６ The ring formed by combining two of these is preferably a non-aromatic ring, more preferably a non-aromatic ring having 5 to 8 ring atoms.

[0134] Each of the above groups in formula (M-4) may have a substituent, and examples of the substituent include the above-mentioned substituent T.

[0135] Specific examples of the monomer corresponding to the repeating unit (U3c) (monomer from which the repeating unit (U3c) is obtained by polymerization reaction) are shown below, but are not limited to these.

[0136]

[0137] When the resin (P) contains the repeating unit (U3c), the content of the repeating unit (U3c) may be 1 mol% or more, 3 mol% or more, or 5 mol% or more, based on the total repeating units in the resin (P). Furthermore, the content of the repeating unit (U3c) may be 45 mol% or less, 40 mol% or less, or 35 mol% or less, based on the total repeating units in the resin (P). When the resin (P) contains the repeating unit (U3c), the repeating unit (U3c) may be one type, or two or more types. When the resin (P) contains two or more types of repeating units (U3c), it is preferable that the total content thereof is within the above range.

[0138] It is also preferred that the resin (P) does not contain the repeating unit (U3c).

[0139] (Repeating unit having a photoacid generating group (repeating unit (U3d))) The repeating unit (U3) may be a repeating unit having a photoacid generating group. A repeating unit having a photoacid generating group that does not fall into either the repeating unit (U1) or the repeating unit (U2) is also referred to as a "repeating unit (U3d)". The photoacid generating group is a group that generates an acid when irradiated with actinic rays or radiation. The resin (P) containing the repeating unit (U3d) can function as a photoacid generator or as an acid diffusion controller, depending on the strength of the acid generated from the photoacid generating group. An example of a repeating unit having a photoacid generating group is a repeating unit represented by formula (4).

[0140]

[0141] R ４１ represents a hydrogen atom or an alkyl group (preferably a methyl group). ４１ represents a single bond or a divalent linking group. ４２ represents a divalent linking group. ４０ represents a structural moiety that decomposes upon irradiation with actinic rays or radiation to generate an acid in the side chain.

[0142] L ４１ represents a single bond or a divalent linking group, and preferably represents a single bond or an ester bond (—COO—).

[0143] L ４２ represents an alkylene group, a cycloalkylene group, an arylene group, —O—, —CO—, —S—, —SO—, —SO ２Preferably, the linking group is at least one selected from the group consisting of - and -NR-. R represents a hydrogen atom or an organic group (preferably an organic group having 1 to 10 carbon atoms, such as an alkyl group, a cycloalkyl group, or an aryl group). The alkylene group may be either linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but preferably 1 to 10. The cycloalkylene group may be a monocyclic cycloalkylene group or a polycyclic cycloalkylene group. The number of carbon atoms in the cycloalkylene group is not particularly limited, but preferably 3 to 20, more preferably 5 to 15. The number of carbon atoms in the arylene group is not particularly limited, but preferably 6 to 20, more preferably 6 to 10. The alkylene group, cycloalkylene group, and arylene group may have a substituent, and examples of the substituent include the substituent T described above.

[0144] R ４０ is preferably a group represented by the following formula (S4-1).

[0145]

[0146] In formula (S4-1), Q － represents an acid residue, M ＋ represents a cation. * represents L ４１ The bond position of the acid residue is a group formed by dissociating a proton from an acid. － is a carboxylate anion group (COO － ), sulfonate anion group (SO ３ － ), or a sulfonamide group (N － -SO ２ R Ｎ１ It is expressed as: R Ｎ１ represents an organic group, and examples thereof include organic groups having 1 to 10 carbon atoms, and an alkyl group, a fluoroalkyl group, or an aryl group is preferred. ＋ The explanation, specific examples and preferred ranges of M in the explanation of the photoacid generator to be described later ＋ is the same as

[0147] Specific examples of repeating units having a photoacid generating group include the repeating units described in

[0094] to

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

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

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

[0148] Examples of the repeating unit represented by formula (4) include the repeating units described in paragraphs

[0094] to

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

[0094] of WO 2018 / 193954 A.

[0149] Specific examples of the monomer corresponding to the repeating unit (U3d) (monomer from which the repeating unit (U3d) is obtained by polymerization reaction) are shown below, but are not limited to these.

[0150]

[0151] When the resin (P) contains the repeating unit (U3d), the content of the repeating unit (U3d) may be 1 mol% or more, 3 mol% or more, or 5 mol% or more, based on the total repeating units in the resin (P). Furthermore, the content of the repeating unit (U3d) may be 40 mol% or less, 35 mol% or less, or 30 mol% or less, based on the total repeating units in the resin (P). When the resin (P) contains the repeating unit (U3d), the repeating unit (U3d) may be one type, or two or more types. When the resin (P) contains two or more types of repeating units (U3d), the total content thereof is preferably within the above range.

[0152] (Repeating Unit Having Neither an Acid-Decomposable Group nor an Acid Group, and Having a Fluorine Atom, a Bromine Atom, or an Iodine Atom) The repeating unit (U3) may be a repeating unit having neither an acid-decomposable group nor an acid group, and having a fluorine atom, a bromine atom, or an iodine atom (hereinafter also referred to as "unit X").

[0153] The unit X is preferably a repeating unit represented by formula (C).

[0154]

[0155] L ５ represents a single bond or an ester group. ９ represents a hydrogen atom or an alkyl group which may have a fluorine atom, a bromine atom or an iodine atom. １０ represents a hydrogen atom, an alkyl group which may have a fluorine atom, a bromine atom, or an iodine atom, a cycloalkyl group which may have a fluorine atom, a bromine atom, or an iodine atom, an aryl group which may have a fluorine atom, a bromine atom, or an iodine atom, or a group combining these. Specific examples of repeating units having a fluorine atom, a bromine atom, or an iodine atom include the repeating units described in paragraphs

[0116] to

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

[0156] When the resin (P) contains the unit X, the content of the unit X may be 1 mol% or more, 5 mol% or more, or 10 mol% or more, based on all repeating units in the resin (P). Furthermore, the content of the unit X may be 40 mol% or less, 35 mol% or less, or 30 mol% or less, based on all repeating units in the resin (P). When the resin (P) contains the unit X, the unit X may be one type, or two or more types. When the resin (P) contains two or more types of the unit X, the total content thereof is preferably within the above range.

[0157] (Repeating Unit Represented by Formula (V-1) or Formula (V-2)) The repeating unit (U3) may be a repeating unit represented by the following formula (V-1) or (V-2).

[0158]

[0159] In the formula, R ６ and R ７each independently represents an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR or -COOR: R is an alkyl group or a fluorinated alkyl group having 1 to 6 carbon atoms), or a carboxyl group. As the alkyl group, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms is preferred. ３ represents an integer of 0 to 6. ４ represents an integer of 0 to 4. ４ is a methylene group, an oxygen atom, or a sulfur atom. Examples of the repeating unit represented by formula (V-1) or (V-2) include the repeating units described in paragraph

[0100] of WO 2018 / 193954.

[0160] (Repeating unit for reducing main chain mobility) The repeating unit (U3) may be a repeating unit for reducing the mobility of the main chain. For repeating units for reducing the mobility of the main chain, the contents of

[0144] to

[0160] of WO 2022 / 024928 are incorporated by reference. The resin (P) preferably has a high glass transition temperature (Tg) in order to suppress excessive diffusion of the generated acid or pattern collapse during development. The Tg is preferably greater than 90°C, more preferably greater than 100°C, even more preferably greater than 110°C, and particularly preferably greater than 125°C. In addition, in terms of excellent dissolution rate in the developer, the Tg is preferably 400°C or less, more preferably 350°C or less. In this specification, the glass transition temperature (Tg) of a polymer such as the resin (P) (hereinafter referred to as "Tg of the repeating unit") is calculated by the following method. First, the Tg of a homopolymer consisting of only each repeating unit contained in the polymer is calculated by the Bicerano method. Next, the mass proportion (%) of each repeating unit relative to all repeating units in the polymer is calculated. Next, the Tg at each mass proportion is calculated using the Fox formula (described in Materials Letters 62 (2008) 3152, etc.), and these are summed to obtain the Tg (°C) of the polymer. The Bicerano method is described in "Prediction of polymer properties," Marcel Dekker Inc., New York (1993). Calculation of Tg by the Bicerano method can be performed using polymer property estimation software MDL Polymer (MDL Information Systems, Inc.).

[0161] (Repeating unit having at least one group selected from a cyano group and an alkali-soluble group) The repeating unit (U3) may be a repeating unit having at least one group selected from a cyano group and an alkali-soluble group. The repeating unit having a cyano group is preferably a repeating unit having a saturated hydrocarbon group having a cyano group (substituted with a cyano group). It may also be a repeating unit having an alicyclic group substituted with a cyano group. The repeating unit having a cyano group preferably does not have an acid-decomposable group. Examples of repeating units having a cyano group include those described in paragraphs

[0081] to

[0084] of JP 2014-098921 A.

[0162] Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bissulfonylimide group, and an aliphatic alcohol group substituted at the α-position with an electron-withdrawing group (e.g., a hexafluoroisopropanol group), and a carboxyl group is preferred. Examples of the repeating unit having an alkali-soluble group include those described in paragraphs

[0085] and

[0086] of JP 2014-098921 A.

[0163] (Repeating Unit Having an Alicyclic Group and Not Exhibiting Acid Decomposability) The repeating unit (U3) may be a repeating unit having an alicyclic group and not exhibiting acid decomposability. Examples of repeating units having an alicyclic group and not exhibiting acid decomposability include repeating units derived from 1-adamantyl(meth)acrylate, diamantyl(meth)acrylate, tricyclodecanyl(meth)acrylate, or cyclohexyl(meth)acrylate.

[0164] (Repeating Unit Represented by Formula (III) Having Neither a Hydroxyl Group nor a Cyano Group) The repeating unit (U3) may be a repeating unit represented by formula (III) having neither a hydroxyl group nor a cyano group.

[0165]

[0166] In formula (III), R ５represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group. Ra represents a hydrogen atom, an alkyl group, or a —CH ２ -O-Ra ２ represents a group. ２ represents a hydrogen atom, an alkyl group, or an acyl group. Examples of the repeating unit represented by formula (III) that does not have either a hydroxyl group or a cyano group include those described in paragraphs

[0087] to

[0094] of JP 2014-098921 A.

[0167] (Other Repeating Units) The repeating unit (U3) may be a repeating unit other than the repeating units described above. The other repeating unit may be, for example, a repeating unit selected from the group consisting of a repeating unit having an oxathiane ring group, a repeating unit having an oxazolone ring group, a repeating unit having a dioxane ring group, and a repeating unit having a hydantoin ring group.

[0168] In addition to the above repeating structural units, the repeating unit (U3) may be a repeating unit that can adjust dry etching resistance, suitability for a standard developer, substrate adhesion, resist profile, resolution, heat resistance, sensitivity, and the like.

[0169] In one preferred embodiment of the present invention, the repeating unit (U2) is the only repeating unit contained in the resin (P) that has a group that is cleaved by the action of an acid.

[0170] In a preferred embodiment of the present invention, the resin (P) contains at least one group selected from the group consisting of a polycyclic lactone group and a polycyclic sultone group.

[0171] In one preferred embodiment of the present invention, the resin (P) contains an alicyclic group having two or more hydroxy groups.

[0172] In one preferred embodiment of the present invention, the resin (P) contains repeating units having a group that is cleaved by the action of an acid in an amount of more than 50 mol % based on the total repeating units.

[0173] In a preferred embodiment of the present invention, the resin (P) contains the repeating unit (U1) in an amount of more than 30 mol % based on the total repeating units.

[0174] Resin (P) can be synthesized according to a conventional method (e.g., radical polymerization). The weight average molecular weight (Mw) of resin (P), as a polystyrene equivalent value measured by GPC, is preferably 30,000 or less, more preferably 1,000 to 30,000, even more preferably 3,000 to 30,000, and particularly preferably 5,000 to 15,000. The dispersity (molecular weight distribution, Mw / Mn) of resin (P) 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 1.5. The smaller the dispersity, the better the resolution and resist shape, and furthermore, the smoother the sidewalls of the resist pattern and the better the roughness.

[0175] The content of resin (P) in the resist composition is preferably 30.0 to 99.9 mass%, more preferably 40.0 to 99.9 mass%, and even more preferably 60.0 to 90.0 mass%, based on the total solid content of the resist composition. Resin (P) may be used alone, or two or more types may be used. When two or more types are used, it is preferable that the total content falls within the above-mentioned suitable content range.

[0176] [Photoacid Generator] The resist composition contains a photoacid generator. The photoacid generator is a compound that generates an acid upon irradiation with actinic rays or radiation. The photoacid generator may be a compound different from the resin (P), or may be the same compound. The photoacid generator is preferably a compound that generates an acid having a pKa of less than 0 upon irradiation with actinic rays or radiation. The pKa of the acid generated from the photoacid generator upon irradiation with actinic rays or radiation is preferably −0.1 or less, more preferably −0.2 or less. Furthermore, the pKa of the acid generated from the photoacid generator upon irradiation with actinic rays or radiation is preferably −1.5 or more, more preferably −1.0 or more.

[0177] The photoacid generator may be in the form of a low molecular weight compound or may be incorporated into a polymer. Furthermore, a photoacid generator in the form of a low molecular weight compound and a photoacid generator in the form of a polymer may be used in combination. When the photoacid generator is in the form of a low molecular weight compound, the molecular weight of the photoacid generator is not particularly limited, but is preferably 100 to 3,000, more preferably 150 to 2,500, and even more preferably 200 to 2,000. When the photoacid generator is incorporated into a polymer, it may be incorporated into the resin (P) or into a resin different from the resin (P). When the resin (P) does not have the repeating unit having a photoacid-generating group described above, the resist composition preferably contains a photoacid generator that is a compound different from the resin (P). When the resin (P) contains a repeating unit having a photoacid-generating group, the resist composition may or may not contain a separate photoacid generator. The photoacid generator is preferably in the form of a low molecular weight compound. The photoacid generator is preferably an onium salt.

[0178] Examples of the photoacid generator include "M ＋ X － ", and it is preferably a compound that generates an organic acid upon exposure. Examples of the organic acid include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphorsulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, aralkyl carboxylic acids, etc.), carbonylsulfonylimido acids, bis(alkylsulfonyl)imido acids, and tris(alkylsulfonyl)methido acids.

[0179] "M ＋ X － In the compound represented by the formula ", M ＋ represents a cation, preferably an organic cation. The cation is not particularly limited. The cation may have a valence of 1 or 2 or more. The cation is preferably a cation represented by formula (ZaI) (hereinafter also referred to as "cation (ZaI)") or a cation represented by formula (ZaII) (hereinafter also referred to as "cation (ZaII)").

[0180]

[0181] In the above formula (ZaI), R ２０１ , R ２０２ , and R ２０３ R each independently represents an organic group. ２０１ , R ２０２ , and R ２０３ The number of carbon atoms in the organic group represented by R is preferably 1 to 30, and more preferably 1 to 20. ２０１ ~R ２０３ Two of these may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ２０１ ~R ２０３ Examples of groups formed by combining two of these include alkylene groups (e.g., butylene and pentylene groups) and —CH ２ -CH ２ -O-CH ２ -CH ２ - are some examples.

[0182] Suitable embodiments of the organic cation in formula (ZaI) include cation (ZaI-1), cation (ZaI-2), cation (ZaI-3b), and cation (ZaI-4b) described below.

[0183] First, the cation (ZaI-1) will be described. The cation (ZaI-1) is R in the above formula (ZaI). ２０１ ~R ２０３ is an arylsulfonium cation, in which at least one of R is an aryl group. ２０１ ~R ２０３ may all be aryl groups, or R ２０１ ~R ２０３ A part of R may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group. ２０１ ~R ２０３ is an aryl group, and R ２０１ ~R ２０３ The remaining two of R may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ２０１ ~R ２０３Examples of groups formed by combining two of the above include alkylene groups in which one or more methylene groups may be substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and / or a carbonyl group (e.g., butylene group, pentylene group, and —CH ２ -CH ２ -O-CH ２ -CH ２ The arylsulfonium cations include triarylsulfonium cations, diarylalkylsulfonium cations, aryldialkylsulfonium cations, diarylcycloalkylsulfonium cations, and aryldicycloalkylsulfonium cations.

[0184] The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of heterocyclic structures include pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, and benzothiophene residues. When the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different. The alkyl group or cycloalkyl group optionally contained in the arylsulfonium cation is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, or a cyclohexyl group.

[0185] R ２０１ ~R ２０３Preferred substituents that the aryl group, alkyl group, and cycloalkyl group may have include alkyl groups (e.g., having 1 to 15 carbon atoms), cycloalkyl groups (e.g., having 3 to 15 carbon atoms), aryl groups (e.g., having 6 to 14 carbon atoms), alkoxy groups (e.g., having 1 to 15 carbon atoms), cycloalkylalkoxy groups (e.g., having 1 to 15 carbon atoms), halogen atoms (e.g., fluorine and iodine), hydroxyl groups, carboxyl groups, ester groups, sulfinyl groups, sulfonyl groups, alkylthio groups, and phenylthio groups. The above substituents may further have substituents if possible, and it is also preferred that the alkyl group has a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group. It is also preferred that the above substituents form an acid-decomposable group in any combination. The acid-decomposable group is intended to be a group that decomposes under the action of acid to generate a polar group, and preferably has a structure in which the polar group is protected by a group that leaves under the action of acid. The above polar groups and leaving groups are as described above.

[0186] Next, the cation (ZaI-2) will be described. The cation (ZaI-2) is a cation represented by the formula (ZaI) R ２０１ ~R ２０３ are each independently a cation representing an organic group that does not have an aromatic ring. The aromatic ring also includes an aromatic ring containing a heteroatom. ２０１ ~R ２０３ The number of carbon atoms of the organic group not having an aromatic ring as R is preferably 1 to 30, and more preferably 1 to 20. ２０１ ~R ２０３ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and still more preferably a linear or branched 2-oxoalkyl group.

[0187] R ２０１ ~R ２０３Examples of the alkyl group and cycloalkyl group in R include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl groups), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl groups). ２０１ ~R ２０３ may be further substituted with a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. ２０１ ~R ２０３ It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0188] Next, the cation (ZaI-3b) will be described. The cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).

[0189]

[0190] In formula (ZaI-3b), R １ｃ ~R ５ｃ R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group. ６ｃ and R ７ｃ R each independently represents a hydrogen atom, an alkyl group (for example, a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group. ｘ and R ｙ R each independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group. １ｃ ~R ７ｃ , and R ｘ and R ｙ It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0191] R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ , R ５ｃ and R ｘ , and R ｘ and R ｙ may be bonded to each other to form a ring, and each of these rings may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the ring include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterocycles, and polycyclic fused rings formed by combining two or more of these rings. Examples of the ring include 3- to 10-membered rings, preferably 4- to 8-membered rings, and more preferably 5- or 6-membered rings.

[0192] R １ｃ ~R ５ｃ Two or more of the following, R ６ｃ and R ７ｃ , and R ｘ and R ｙ Examples of the group formed by bonding of R include alkylene groups such as butylene and pentylene. The methylene group in this alkylene group may be substituted with a heteroatom such as an oxygen atom. ５ｃ and R ６ｃ , and R ５ｃ and R ｘ The group formed by bonding is preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group.

[0193] 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 ｙThe ring formed by bonding together may have a substituent.

[0194] Next, the cation (ZaI-4b) will be described. The cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).

[0195]

[0196] In formula (ZaI-4b), l represents an integer of 0 to 2, and r represents an integer of 0 to 8. １３ represents a hydrogen atom, a halogen atom (for example, a fluorine atom or an iodine atom), a hydroxyl group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a group containing a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent. R １４ represents a hydroxyl group, a halogen atom (for example, a fluorine atom or an iodine atom), an alkyl group, a halogenated alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group containing a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent. R １４ When a plurality of R are present, each independently represents the above group such as a hydroxyl group. １５ each independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. １５ may be bonded to each other to form a ring. １５ When two R are bonded to each other to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom. １５ are preferably alkylene groups and bonded to each other to form a ring structure. １５ The ring formed by bonding together may have a substituent.

[0197] In formula (ZaI-4b), R １３ , R１４ , and R １５ The alkyl group in R may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1 to 10. The alkyl group is preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like. １３ ~R １５ , and R ｘ and R ｙ It is also preferred that each of the substituents independently form an acid-decomposable group by any combination of the substituents.

[0198] Next, formula (ZaII) will be described. In formula (ZaII), R ２０４ and R ２０５ R each independently represents an aryl group, an alkyl group, or a cycloalkyl group. ２０４ and R ２０５ The aryl group in R is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. ２０４ and R ２０５ The aryl group in R may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. ２０４ and R ２０５ The alkyl group and cycloalkyl group are preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, or pentyl), or a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, or norbornyl).

[0199] R ２０４ and R ２０５ The aryl group, alkyl group, and cycloalkyl group in R may each independently have a substituent. ２０４ and R ２０５Examples of the substituents that the aryl group, alkyl group, and cycloalkyl group may have include alkyl groups (e.g., having 1 to 15 carbon atoms), cycloalkyl groups (e.g., having 3 to 15 carbon atoms), aryl groups (e.g., having 6 to 15 carbon atoms), alkoxy groups (e.g., having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups. ２０４ and R ２０５ It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0200] Specific examples of organic cations are shown below, but are not limited to these.

[0201]

[0202]

[0203]

[0204]

[0205] "M ＋ X － In the compound represented by the formula "X － represents an anion, preferably an organic anion. The anion is not particularly limited, and examples thereof include monovalent or divalent or higher anions. The anion is preferably an anion having a significantly low ability to cause a nucleophilic reaction, and more preferably a non-nucleophilic anion.

[0206] Examples of non-nucleophilic anions include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, camphorsulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, aralkyl carboxylate anions, etc.), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

[0207] The aliphatic moiety in the aliphatic sulfonate anion and the aliphatic carboxylate anion may be a linear or branched alkyl group or a cycloalkyl group, and is preferably a linear or branched alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms. The alkyl group may be, for example, a fluoroalkyl group (which may have a substituent other than a fluorine atom, or may be a perfluoroalkyl group).

[0208] The aryl group in the aromatic sulfonate anion and aromatic carboxylate anion is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a tolyl group, and a naphthyl group.

[0209] The alkyl group, cycloalkyl group, and aryl group mentioned above may have a substituent. The substituent is not particularly limited, but examples thereof include a nitro group, a halogen atom such as a fluorine atom or a chlorine atom, a carboxyl group, a hydroxyl group, an amino group, a cyano group, an alkoxy group (preferably having 1 to 15 carbon atoms), an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 3 to 15 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably having 2 to 7 carbon atoms), an acyl group (preferably having 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), an alkylthio group (preferably having 1 to 15 carbon atoms), an alkylsulfonyl group (preferably having 1 to 15 carbon atoms), an alkyliminosulfonyl group (preferably having 1 to 15 carbon atoms), and an aryloxysulfonyl group (preferably having 6 to 20 carbon atoms).

[0210] The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 7 to 14 carbon atoms. Examples of the aralkyl group having 7 to 14 carbon atoms include a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylbutyl group.

[0211] An example of the sulfonylimide anion is a saccharin anion.

[0212] The alkyl group in the bis(alkylsulfonyl)imide anion and the tris(alkylsulfonyl)methide anion is preferably an alkyl group having 1 to 5 carbon atoms. Substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, and cycloalkylaryloxysulfonyl groups, with fluorine atoms or alkyl groups substituted with fluorine atoms being preferred. Furthermore, the alkyl groups in the bis(alkylsulfonyl)imide anion may be bonded to each other to form a ring structure, which increases the acid strength.

[0213] Other non-nucleophilic anions include, for example, phosphorus fluorides (e.g., PF ６ － ), boron fluorides (e.g., BF ４ － ), and antimony fluorides (e.g., SbF ６ － ) are listed.

[0214] Preferred non-nucleophilic anions include aliphatic sulfonate anions in which at least the α-position of the sulfonic acid is substituted with a fluorine atom, aromatic sulfonate anions substituted with a fluorine atom or a group having a fluorine atom, bis(alkylsulfonyl)imide anions in which an alkyl group is substituted with a fluorine atom, and tris(alkylsulfonyl)methide anions in which an alkyl group is substituted with a fluorine atom. Among these, perfluoroaliphatic sulfonate anions (preferably having 4 to 8 carbon atoms) and benzenesulfonate anions having a fluorine atom are more preferred, and nonafluorobutanesulfonate anions, perfluorooctanesulfonate anions, pentafluorobenzenesulfonate anions, and 3,5-bis(trifluoromethyl)benzenesulfonate anions are even more preferred.

[0215] The non-nucleophilic anion is also preferably an anion represented by the following formula (AN1).

[0216]

[0217] In formula (AN1), R１ and R ２ each independently represents a hydrogen atom or a substituent. The substituent is not particularly limited, but a group that is not an electron-withdrawing group is preferred. Examples of groups that are not electron-withdrawing groups include hydrocarbon groups, hydroxyl groups, oxyhydrocarbon groups, oxycarbonyl hydrocarbon groups, amino groups, hydrocarbon-substituted amino groups, and hydrocarbon-substituted amide groups. Examples of groups that are not electron-withdrawing groups include, each independently, -R', -OH, -OR', -OCOR', -NH ２ , -NR' ２ , —NHR′, or —NHCOR′ is preferred, where R′ is a monovalent hydrocarbon group.

[0218] Examples of the monovalent hydrocarbon group represented by R' include monovalent linear or branched hydrocarbon groups such as alkyl groups such as methyl, ethyl, propyl, and butyl; alkenyl groups such as ethenyl, propenyl, and butenyl; alkynyl groups such as ethynyl, propynyl, and butynyl; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl; monovalent alicyclic hydrocarbon groups such as cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and norbornenyl; aryl groups such as phenyl, tolyl, xylyl, mesityl, naphthyl, methylnaphthyl, anthryl, and methylanthryl; and aralkyl groups such as benzyl, phenethyl, phenylpropyl, naphthylmethyl, and anthrylmethyl. Among these, R １ and R ２ are each independently preferably a hydrocarbon group (preferably a cycloalkyl group) or a hydrogen atom.

[0219] L represents a divalent linking group. When a plurality of L's are present, they may be the same or different. Examples of the divalent linking group include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -S-, -SO-, and -SO ２Examples of the divalent linking group include -, an alkylene group (preferably having 1 to 6 carbon atoms), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), and a divalent linking group formed by combining a plurality of these groups. Among these, examples of the divalent linking group include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, and -SO ２ -, -O-CO-O-alkylene group-, -COO-alkylene group-, or -CONH-alkylene group- is preferred, and -O-CO-O-, -O-CO-O-alkylene group-, -COO-, -CONH-, or -SO ２ - or -COO-alkylene group- is more preferred.

[0220] As L, for example, a group represented by the following formula (AN1-1) is preferable: ａ - (CR ２ａ ２ ) Ｘ -Q-(CR ２ｂ ２ ) Ｙ -* ｂ (AN1-1)

[0221] In formula (AN1-1), * ａ is R in formula (AN1). ３ Represents the bonding position with * ｂ represents -C(R １ ) (R ２ X and Y each independently represent an integer of 0 to 10, preferably an integer of 0 to 3. R ２ａ and R ２ｂ R each independently represents a hydrogen atom or a substituent. ２ａ and R ２ｂ When there are multiple R ２ａ and R ２ｂ may be the same or different, provided that when Y is 1 or more, -C(R １ ) (R ２ )- and CR directly bonded ２ｂ ２ R in ２ｂ is other than a fluorine atom. Q is * Ａ -O-CO-O-*Ｂ , * Ａ -CO-* Ｂ , * Ａ -CO-O-* Ｂ , * Ａ -O-CO-* Ｂ , * Ａ -O-* Ｂ , * Ａ -S-* Ｂ , or * Ａ -SO ２ -* Ｂ where X+Y in formula (AN1-1) is 1 or more, and R ２ａ and R ２ｂ are all hydrogen atoms, Q is * Ａ -O-CO-O-* Ｂ , * Ａ -CO-* Ｂ , * Ａ -O-CO-* Ｂ , * Ａ -O-* Ｂ , * Ａ -S-* Ｂ , or * Ａ -SO ２ -* Ｂ Represents. Ａ is R in formula (AN1). ３ represents the bonding position on the side, and * Ｂ represents -SO in formula (AN1). ３ － represents the bonding position on the side.

[0222] In formula (AN1), R ３ represents an organic group. The organic group is not particularly limited as long as it has one or more carbon atoms, and may be a linear group (for example, a linear alkyl group), a branched group (for example, a branched alkyl group such as a t-butyl group), or a cyclic group. The organic group may or may not have a substituent. The organic group may or may not have a heteroatom (such as an oxygen atom, a sulfur atom, and / or a nitrogen atom).

[0223] Among them, R ３is preferably an organic group having a cyclic structure. The cyclic structure may be monocyclic or polycyclic and may have a substituent. The ring in the organic group having a cyclic structure is preferably directly bonded to L in formula (AN1). The organic group having a cyclic structure may or may not have a heteroatom (oxygen atom, sulfur atom, and / or nitrogen atom, etc.). The heteroatom may be substituted for one or more of the carbon atoms forming the cyclic structure. The organic group having a cyclic structure is preferably, for example, a hydrocarbon group having a cyclic structure, a lactone ring group, or a sultone ring group. Among these, the organic group having a cyclic structure is preferably a hydrocarbon group having a cyclic structure. The hydrocarbon group having a cyclic structure is preferably a monocyclic or polycyclic cycloalkyl group. These groups may have a substituent. The cycloalkyl group may be monocyclic (e.g., a cyclohexyl group) or polycyclic (e.g., an adamantyl group), and preferably has 5 to 12 carbon atoms. As the lactone group and sultone group, for example, a group in which one hydrogen atom has been removed from a ring atom constituting the lactone structure or sultone structure in any of the structures represented by the above-mentioned formulae (LC1-1) to (LC1-22) and the structures represented by the above-mentioned formulae (SL1-1) to (SL1-3) is preferred.

[0224] R ３ Preferably, R contains a halogen atom. ３ The halogen atom contained in is preferably a fluorine atom or an iodine atom, and more preferably an iodine atom. When the resist composition is used as an EUV resist, the number of halogen atoms is preferably as large as possible from the viewpoint of the efficiency of absorbing EUV light. When an iodine atom is contained, a structure in which the iodine atom is directly bonded to a carbon atom on an aromatic ring is preferred.

[0225] As the anion represented by formula (AN1), the anions described in

[0040] to

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

[0226] The non-nucleophilic anion may be a benzenesulfonate anion, and is preferably a benzenesulfonate anion substituted with a branched alkyl group or a cycloalkyl group.

[0227] The non-nucleophilic anion is also preferably an anion represented by the following formula (AN2).

[0228]

[0229] In formula (AN2), o represents an integer of 1 to 3. p represents an integer of 0 to 10. q represents an integer of 0 to 10.

[0230] Xf represents a hydrogen atom, a fluorine atom, an alkyl group substituted with at least one fluorine atom, or an organic group having no fluorine atoms. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. The alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group. Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, and is preferably a fluorine atom or CF ３ It is more preferable that both Xf's are fluorine atoms.

[0231] R ４ and R ５ R each independently represents a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom. ４ and R ５ If there are multiple ４ and R ５ may be the same or different. ４ and R ５ The alkyl group represented by the formula (I) preferably has 1 to 4 carbon atoms. The alkyl group may have a substituent. ４ and R ５ is preferably a hydrogen atom.

[0232] L represents a divalent linking group, and is defined the same as L in formula (AN1).

[0233] W represents an organic group containing a cyclic structure. Among these, a cyclic organic group is preferred. Examples of the cyclic organic group include an alicyclic group, an aryl group, and a heterocyclic group. The alicyclic group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include a monocyclic cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic group include a polycyclic cycloalkyl group such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Among these, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group, are preferred.

[0234] The aryl group may be monocyclic or polycyclic. Examples of the aryl group include a phenyl group, a naphthyl group, a phenanthryl group, and an anthryl group. The heterocyclic group may be monocyclic or polycyclic. In particular, a polycyclic heterocyclic group can further suppress the diffusion of acid. The heterocyclic group may or may not have aromaticity. Examples of heterocyclic rings having aromaticity include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and a pyridine ring. Examples of heterocyclic rings having no aromaticity include a tetrahydropyran ring, a lactone ring, a sultone ring, and a decahydroisoquinoline ring. The heterocyclic ring in the heterocyclic group is preferably a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring.

[0235] The cyclic organic group may have a substituent. Examples of the substituent include an alkyl group (which may be either linear or branched, and preferably has 1 to 12 carbon atoms), a cycloalkyl group (which may be either monocyclic, polycyclic, or spirocyclic, and preferably has 3 to 20 carbon atoms), an aryl group (which preferably has 6 to 14 carbon atoms), a hydroxyl group, an alkoxy group, an ester group, an amide group, a urethane group, a ureido group, a thioether group, a sulfonamide group, and a sulfonate ester group. The carbon constituting the cyclic organic group (the carbon that contributes to ring formation) may be a carbonyl carbon.

[0236] W preferably contains a halogen atom. The halogen atom contained in W is preferably a fluorine atom or an iodine atom, and more preferably an iodine atom. When the resist composition is used as an EUV resist, the greater the number of halogen atoms, the better from the viewpoint of the absorption efficiency of EUV light. When an iodine atom is contained, a structure in which the iodine atom is directly bonded to a carbon atom on an aromatic ring is preferred.

[0237] As the anion represented by formula (AN2), the anions described in

[0076] of WO 2023 / 157455,

[0071] to

[0089] of JP-A 2021-81708,

[0033] to

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

[0031] to

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

[0238] The anion represented by formula (AN2) is SO ３ － -CF ２ -CH ２ -OCO-(L) ｑ’ -W, SO ３ － -CF ２ -CHF-CH ２ -OCO-(L) ｑ’ -W, SO ３ － -CF ２ -COO-(L) ｑ’ -W, SO ３ － -CF ２ -CF ２ -CH ２ -CH２ - (L) ｑ -W or SO ３ － -CF ２ -CH(CF ３ ) -OCO-(L) ｑ’ -W is preferred. Here, L, q and W are the same as those in formula (AN2). q' represents an integer of 0 to 10.

[0239] The non-nucleophilic anion is also preferably an aromatic sulfonate anion represented by the following formula (AN3).

[0240]

[0241] In formula (AN3), Ar represents an aryl group (such as a phenyl group) and may further have a substituent other than the sulfonate anion and the -(D-B) group. Examples of the substituent that may further be had include a fluorine atom and a hydroxyl group. n represents an integer of 0 or greater. n is preferably 1 to 4, more preferably 2 to 3, and even more preferably 3.

[0242] D represents a single bond or a divalent linking group. Examples of the divalent linking group include an ether group, a thioether group, a carbonyl group, a sulfoxide group, a sulfone group, a sulfonate ester group, an ester group, and a group formed by combining two or more of these groups.

[0243] B represents a hydrocarbon group. B is preferably an aliphatic hydrocarbon group, and more preferably an isopropyl group, a cyclohexyl group, or an aryl group which may further have a substituent (such as a tricyclohexylphenyl group).

[0244] B preferably contains a halogen atom. The halogen atom contained in B is preferably a fluorine atom or an iodine atom, and more preferably an iodine atom. When the resist composition is used as an EUV resist, the greater the number of halogen atoms, the better, from the viewpoint of the absorption efficiency of EUV light. When an iodine atom is contained, a structure in which the iodine atom is directly bonded to a carbon atom on an aromatic ring is preferred.

[0245] As the anion represented by formula (AN3), the anions described in

[0029] to

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

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

[0246] As the non-nucleophilic anion, a disulfonamide anion is also preferred. The disulfonamide anion is, for example, N － (SO ２ -R ｑ ) ２ where R ｑ represents an alkyl group which may have a substituent, preferably a fluoroalkyl group, more preferably a perfluoroalkyl group. ｑ may be bonded to each other to form a ring. ｑ The group formed by bonding together is preferably an alkylene group which may have a substituent, more preferably a fluoroalkylene group, and even more preferably a perfluoroalkylene group. The alkylene group preferably has 2 to 4 carbon atoms.

[0247] Further, examples of the non-nucleophilic anion include anions represented by the following formulas (d1-1) to (d1-4).

[0248]

[0249] In formula (d1-1), R ５１ represents a hydrocarbon group (for example, an aryl group such as a phenyl group) which may have a substituent (for example, a hydroxyl group).

[0250] In formula (d1-2), Z ２ｃ represents a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (provided that the carbon atom adjacent to S is not substituted with a fluorine atom). ２ｃThe hydrocarbon group in the formula (d1-2) may be linear or branched, or may have a cyclic structure. In addition, a carbon atom in the hydrocarbon group (preferably, a carbon atom that is a ring atom when the hydrocarbon group has a cyclic structure) may be a carbonyl carbon (-CO-). Examples of the hydrocarbon group include a group having a norbornyl group that may have a substituent. The carbon atom forming the norbornyl group may be a carbonyl carbon. ２ｃ -SO ３ － " is preferably different from the anions represented by the above formulae (AN1) to (AN3). For example, Z ２ｃ is preferably other than an aryl group. For example, Z ２ｃ In the -SO ３ － The atoms at the α-position and β-position to Z are preferably atoms other than carbon atoms having a fluorine atom as a substituent. ２ｃ is -SO ３ － The atom at the α-position and / or the atom at the β-position to the aryl group is preferably a ring atom in a cyclic group.

[0251] In formula (d1-3), R ５２ represents an organic group (preferably a hydrocarbon group having a fluorine atom), Y ３ represents a linear, branched, or cyclic alkylene group, an arylene group, or a carbonyl group, and Rf represents a hydrocarbon group.

[0252] In formula (d1-4), R ５３ and R ５４ R each independently represents an organic group (preferably a hydrocarbon group having a fluorine atom). ５３ and R ５４ may be bonded to each other to form a ring.

[0253] The organic anions may be used alone or in combination of two or more.

[0254] It is also preferable that the photoacid generator is at least one selected from the group consisting of compounds (I) to (II).

[0255] (Compound (I)) Compound (I) is a compound having one or more structural moieties X and one or more structural moieties Y, which generates an acid containing the first acidic moiety derived from the structural moiety X and the second acidic moiety derived from the structural moiety Y when irradiated with actinic rays or radiation. Structural moiety X: Anionic moiety A １ － and the cationic moiety M １ ＋ and by irradiation with actinic rays or radiation, HA １ Structural moiety Y: anionic moiety A, which forms a first acidic moiety represented by the formula: ２ － and the cationic moiety M ２ ＋ and by irradiation with actinic rays or radiation, HA ２ The compound (I) satisfies the following condition I:

[0256] Condition I: In the compound (I), the cationic moiety M in the structural moiety X １ ＋ and the cationic moiety M in the structural moiety Y ２ ＋ H ＋ The compound PI in which the cation moiety M in the structural moiety X is replaced by １ ＋ H ＋ HA is replaced by １ and the cationic moiety M in the structural moiety Y. ２ ＋ H ＋ HA is replaced by ２ and an acid dissociation constant a2 derived from the acidic site represented by the formula (I), and the acid dissociation constant a2 is greater than the acid dissociation constant a1.

[0257] Condition I will be explained in more detail below. For example, when compound (I) is an acid-generating compound having one of the first acidic sites derived from the structural moiety X and one of the second acidic sites derived from the structural moiety Y, compound PI is "HA １ and H.A.２ The acid dissociation constant a1 and the acid dissociation constant a2 of the compound PI correspond to "a compound having the following structure." More specifically, when the acid dissociation constant of the compound PI is calculated, the acid dissociation constant a1 and the acid dissociation constant a2 of the compound PI correspond to "a compound having the following structure." １ － and H.A. ２ The pKa at which the compound becomes "a compound having the above formula (A)" is the acid dissociation constant a1, １ － and H.A. ２ "A compound having １ － and A ２ － The pKa at which the compound becomes "a compound having the above formula (I)" is the acid dissociation constant a2.

[0258] For example, when compound (I) is an acid-generating compound having two of the first acidic sites derived from the structural site X and one of the second acidic sites derived from the structural site Y, compound PI is a compound having two HAs. １ and one HA ２ When the acid dissociation constant of compound PI is calculated, compound PI corresponds to "a compound having one A １ － and one HA １ and one HA ２ and the acid dissociation constant when "a compound having one A １ － and one HA １ and one HA ２ "Compound having two A １ － and one HA ２ The acid dissociation constant when the compound is a compound having two A's corresponds to the acid dissociation constant a1. １ － and one HA ２ "Compound having two A １ － and A ２ － In other words, in the case of compound PI, the acid dissociation constant when the compound becomes a compound having the cation moiety M in the structural moiety X corresponds to the acid dissociation constant a2. １ ＋ H ＋ HA is replaced by１ When the compound PI has a plurality of acid dissociation constants derived from the acidic moiety represented by the formula (I), the value of the acid dissociation constant a2 is larger than the largest value of the plurality of acid dissociation constants a1. １ － and one HA １ and one HA ２ The acid dissociation constant when the compound is aa is defined as "a compound having one A １ － and one HA １ and one HA ２ "Compound having two A １ － and one HA ２ When the acid dissociation constant when the compound becomes "a compound having the formula (I)" is ab, the relationship between aa and ab satisfies aa<ab.

[0259] The acid dissociation constants a1 and a2 are determined by the above-mentioned method for measuring an acid dissociation constant. The compound PI corresponds to an acid generated when compound (I) is irradiated with actinic rays or radiation. When compound (I) has two or more structural moieties X, the structural moieties X may be the same or different. In addition, when two or more of the above A １ － and two or more of the above M １ ＋ In compound (I), the above A １ － and the above A ２ － , and the above M １ ＋ and the above M ２ ＋ may be the same or different, but １ － and the above A ２ － are preferably different from each other.

[0260] In the compound PI, the difference (absolute value) between the acid dissociation constant a1 (the maximum value when there are multiple acid dissociation constants a1) and the acid dissociation constant a2 is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 1.0 or more. The upper limit of the difference (absolute value) between the acid dissociation constant a1 (the maximum value when there are multiple acid dissociation constants a1) and the acid dissociation constant a2 is not particularly limited, but is, for example, 16 or less.

[0261] In the compound PI, the acid dissociation constant a2 is preferably not more than 20, more preferably not more than 15. The lower limit of the acid dissociation constant a2 is preferably not less than −4.0.

[0262] In the compound PI, the acid dissociation constant a1 is preferably 2.0 or less, and more preferably 0 or less. The lower limit of the acid dissociation constant a1 is preferably −20.0 or more.

[0263] Anion site A １ － and anionic moiety A ２ － is a structural moiety containing a negatively charged atom or atomic group, and examples thereof include structural moieties selected from the group consisting of formulae (AA-1) to (AA-3) and formulae (BB-1) to (BB-6) shown below. １ － As the anionic moiety A, those capable of forming an acidic moiety with a small acid dissociation constant are preferred, and among these, any of formulas (AA-1) to (AA-3) is more preferred, and any of formulas (AA-1) and (AA-3) is even more preferred. ２ － As the anion moiety A １ － Preferably, it is one that can form an acidic site with a larger acid dissociation constant than the above, more preferably any of formulas (BB-1) to (BB-6), and even more preferably any of formulas (BB-1) and (BB-4). In the following formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6), * represents a bonding position. In formula (AA-2), R Ａ represents a monovalent organic group. ＡThe monovalent organic group represented by the formula (I) is not particularly limited, but examples thereof include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

[0264]

[0265]

[0266] Cationic moiety M １ ＋ and cationic moiety M ２ ＋ is a structural moiety containing a positively charged atom or atomic group, and examples thereof include organic cations having a monovalent charge. ＋ Examples of the organic cation include those represented by the following formula:

[0267] (Compound (II)) Compound (II) is a compound having two or more of the above structural moieties X and one or more of the following structural moieties Z, which generates an acid containing two or more of the first acidic moieties derived from the structural moiety X and the structural moiety Z upon irradiation with actinic rays or radiation. Structural moiety Z: a ​​nonionic moiety capable of neutralizing an acid

[0268] In compound (II), the definition of the structural moiety X and A １ － and M １ ＋ The definition of the structural moiety X in compound (I) and A １ － and M １ ＋ The definition and preferred embodiments are also the same.

[0269] In the compound (II), the cation moiety M in the structural moiety X １ ＋ H ＋ In the compound PII, the cationic moiety M in the structural moiety X is replaced by １ ＋ H ＋ HA is replaced by １The preferred range of the acid dissociation constant a1 derived from the acidic moiety represented by the formula (I) is the same as the acid dissociation constant a1 in the compound PI. In addition, when the compound (II) is, for example, a compound that generates an acid having two of the first acidic moieties derived from the structural moiety X and the structural moiety Z, the compound PII is a compound that generates an acid having two HAs. １ When the acid dissociation constant of this compound PII was calculated, it was found that the compound PII has "one A １ － and one HA １ and the acid dissociation constant when "a compound having one A １ － and one HA １ "Compound having two A １ － The acid dissociation constant when the compound becomes "a compound having the formula (I)" corresponds to the acid dissociation constant a1.

[0270] The acid dissociation constant a1 can be determined by the above-mentioned method for measuring an acid dissociation constant. The compound PII corresponds to the acid generated when compound (II) is irradiated with actinic rays or radiation. The two or more structural moieties X may be the same or different. １ － and two or more of the above M １ ＋ may be the same or different.

[0271] The nonionic moiety capable of neutralizing an acid in the structural moiety Z is not particularly limited, and is preferably, for example, a moiety containing a group capable of electrostatically interacting with a proton or a functional group having electrons. Examples of the group capable of electrostatically interacting with a proton or the functional group having electrons include functional groups having a macrocyclic structure such as cyclic polyethers, and functional groups having a nitrogen atom with an unshared electron pair that does not contribute to π-conjugation. The nitrogen atom with an unshared electron pair that does not contribute to π-conjugation is, for example, a nitrogen atom having a partial structure shown in the following formula:

[0272]

[0273] Examples of the partial structure of a functional group having a group or electron capable of electrostatically interacting with a proton include a crown ether structure, an azacrown ether structure, a primary amine structure, a secondary amine structure, a tertiary amine structure, a pyridine structure, an imidazole structure, and a pyrazine structure. Of these, a primary amine structure, a secondary amine structure, a tertiary amine structure, and a tertiary amine structure are preferred.

[0274] Examples of moieties other than cations that Compound (I) and Compound (II) may have are shown below.

[0275]

[0276]

[0277] In a preferred embodiment of the present invention, the photoacid generator contains an iodine atom.

[0278] In a preferred embodiment of the present invention, the photoacid generator is an onium salt, and the onium salt contains a cation having a fluorine atom.

[0279] In a preferred embodiment of the present invention, the photoacid generator is an onium salt, and the onium salt contains an anion having an iodine atom.

[0280] 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, based on 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 30.0% by mass or less, and even more preferably 25.0% by mass or less, based on the total solid content of the resist composition. Only one photoacid generator may be used, or two or more types may be used. When two or more photoacid generators are used, the total content thereof is preferably within the above-mentioned preferred content range.

[0281] [Acid Diffusion Controller] The resist composition may further contain an acid diffusion controller. The acid diffusion controller can act as a quencher that traps acid generated, for example, from a photoacid generator during exposure and suppresses reaction of the resin (P) in unexposed areas due to excess generated acid. The acid diffusion controller may be a compound different from the resin (P) or the same compound. The acid diffusion controller may be a compound different from the photoacid generator or the same compound. The acid diffusion controller may be in the form of a low molecular weight compound or may be incorporated into a part of a polymer. Alternatively, an acid diffusion controller in the form of a low molecular weight compound and an acid diffusion controller in the form of an acid diffusion controller incorporated into a part of a polymer may be used in combination. When the acid diffusion controller is incorporated into a part of a polymer, it may be incorporated into a part of the resin (P) or into a resin different from the resin (P). When the resin (P) does not have the repeating unit having a photoacid generating group that functions as the acid diffusion controller, the resist composition preferably contains an acid diffusion controller that is a compound different from the resin (P). When the resin (P) contains a repeating unit having a photoacid-generating group that functions as an acid diffusion controller, the resist composition may or may not contain a separate acid diffusion controller.

[0282] The type of acid diffusion controller is not particularly limited, and examples thereof include a basic compound (DA), a low-molecular-weight compound (DB) having a nitrogen atom and a group that is cleaved by the action of an acid, and a compound (DC) whose acid diffusion control ability is reduced or eliminated by irradiation with actinic rays or radiation. Examples of the compound (DC) include an onium salt compound (DD) of an acid that is relatively weaker than the acid generated from the photoacid generator, and a basic compound (DE) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation.

[0283] (Basic Compound (DA)) As the basic compound (DA), compounds having structures represented by the following formulae (A) to (E) are preferred.

[0284]

[0285] In formulas (A) and (E), R ２００ , R２０１ and R ２０２ may be the same or different, and each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms), or an aryl group (preferably having 6 to 20 carbon atoms). ２００ , R ２０１ and R ２０２ At least two of R may be bonded to form a ring. ２０３ , R ２０４ , R ２０５ and R ２０６ may be the same or different, and each independently represents an alkyl group having 1 to 20 carbon atoms. In formulas (B), (C), (D), and (E), * represents a bonding position.

[0286] R in formulas (A) and (E) ２００ , R ２０１ , R ２０２ , R ２０３ , R ２０４ , R ２０５ and R ２０６ The alkyl group or cycloalkyl group represented by may have a substituent or may be unsubstituted. With regard to the alkyl group, the alkyl group having a substituent is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms. R in formulas (A) and (E) ２００ , R ２０１ , R ２０２ , R ２０３ , R ２０４ , R ２０５ and R ２０６ The alkyl group or cycloalkyl group represented by is more preferably unsubstituted.

[0287] Examples of the basic compound (DA) include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine. The basic compound (DA) may be a compound having at least one structure selected from the group consisting of an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure, and a pyridine structure. The basic compound (DA) may be an alkylamine derivative having at least one structure selected from the group consisting of a hydroxyl group and an ether bond, or an aniline derivative having at least one structure selected from the group consisting of a hydroxyl group and an ether bond.

[0288] The difference between the pKa of the conjugate acid of the basic compound (DA) and the pKa of the acid generated from the photoacid generator (the value obtained by subtracting the pKa of the acid generated from the photoacid generator from the pKa of the conjugate acid of the basic compound (DA)) is preferably 1.00 or more, more preferably 1.00 to 14.00, and even more preferably 2.00 to 13.00. The pKa of the conjugate acid of the basic compound (DA) varies depending on the type of photoacid generator used, but is, for example, preferably 1.00 to 14.00, more preferably 3.00 to 13.00, and even more preferably 3.50 to 12.50.

[0289] (Onium Salt Compound (DD) of an Acid that is Relatively Weaker than the Acid Generated from a Photoacid Generator) The compound (DD) may be a compound that generates an acid upon irradiation with actinic rays or radiation. The compound (DD) is preferably a compound that generates an acid that has a pKa that is 1.00 or more higher than that of the acid generated from the photoacid generator. The difference between the pKa of the acid generated from the compound (DD) and the pKa of the acid generated from the photoacid generator (the value obtained by subtracting the pKa of the acid generated from the photoacid generator from the pKa of the acid generated from the compound (DD)) is preferably 1.00 or more, more preferably 1.00 to 10.00, even more preferably 1.00 to 5.00, and particularly preferably 1.00 to 3.00. The pKa of the acid generated from compound (DD) varies depending on the type of photoacid generator used, but is preferably, for example, 0.50 to 10.00, more preferably 0.80 to 5.00, and even more preferably 1.00 to 5.00.

[0290] Compound (DD) is preferably an onium salt compound consisting of an anion and a cation. Examples of compound (DD) include "M ＋ X － " (preferably an onium salt). ＋ represents a cation, and preferably represents an organic cation. － represents an anion, and preferably represents an organic anion. ＋ As the photoacid generator, M ＋ The same as above can be mentioned. － Examples of the anion include the anions represented by formulas (d1-1) to (d1-4) described in the description of the photoacid generator, and the anion represented by formula (d1-1) or the anion represented by formula (d1-2) is preferred.

[0291] Specific examples of the basic compound (DA) include those described in paragraphs

[0132] to

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

[0137] to

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

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

[0156] to

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

[0305] to

[0314] of WO 2020 / 158337.

[0292] In addition to the above, for example, known compounds disclosed in paragraphs

[0627] to

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

[0095] to

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

[0403] to

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

[0259] to

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

[0293] The molecular weight of the acid diffusion controller is not particularly limited, but is preferably from 100 to 3,000, more preferably from 150 to 2,500, and even more preferably from 200 to 2,000.

[0294] The acid diffusion controller is also preferably a compound that generates an acid having a pKa of 0 or more upon irradiation with actinic rays or radiation.

[0295] When the resist composition contains an acid diffusion controller, the content of the acid diffusion controller is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, based on the total solid content of the resist composition. Furthermore, the content of the acid diffusion controller is preferably 50.0% by mass or less, more preferably 40.0% by mass or less, and even more preferably 30.0% by mass or less, based on the total solid content of the resist composition. Only one acid diffusion controller may be used, or two or more may be used. When two or more types are used, the total content is preferably within the above-mentioned preferred content range.

[0296] [Hydrophobic Resin] The resist composition may further contain a hydrophobic resin different from the resin (P). The hydrophobic resin is preferably designed so that it is unevenly distributed on the surface of the resist film, but unlike surfactants, it does not necessarily have to have a hydrophilic group in its molecule, and it does not necessarily have to contribute to uniform mixing of the polar substance and the non-polar substance.

[0297] The hydrophobic resin contains fluorine atoms, silicon atoms, and CH atoms contained in the side chain portion of the resin in order to be unevenly distributed on the surface layer of the film. ３ It is preferable to have one or more of the partial structures, and more preferably two or more. The hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted on a side chain. Examples of hydrophobic resins include the compounds described in paragraphs

[0275] to

[0279] of WO 2020 / 004306.

[0298] When the resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01 to 20.0 mass%, and more preferably 0.1 to 15.0 mass%, based on the total solids content of the resist composition. Only one type of hydrophobic resin may be used, or two or more types may be used. When two or more types are used, the total content thereof preferably falls within the above-mentioned preferred content range.

[0299] [Surfactant] The resist composition may contain a surfactant. When the resist composition contains a surfactant, it is possible to form a pattern with better adhesion and fewer development defects. The surfactant is preferably a fluorine-based and / or silicon-based surfactant. Examples of the fluorine-based and / or silicon-based surfactant include the surfactants disclosed in paragraphs

[0218] and

[0219] of WO 2018 / 193954.

[0300] When the resist composition contains a surfactant, the content of the surfactant is preferably 0.0001 to 2.0 mass%, more preferably 0.0005 to 1.0 mass%, and even more preferably 0.1 to 1.0 mass%, relative to the total solids content of the resist composition. One type of surfactant may be used, or two or more types may be used. When two or more types are used, it is preferable that the total content thereof is within the above-mentioned preferred content range.

[0301] [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, lactate ester, acetate ester, alkoxypropionate ester, chain ketone, cyclic ketone, lactone, and alkylene carbonate. The solvent may further contain components other than components (M1) and (M2).

[0302] Combining the above-mentioned solvent with the above-mentioned resin is preferable in terms of improving the coatability of the resist composition and reducing the number of development defects in the pattern. The above-mentioned solvent has a good balance of the solubility, boiling point, and viscosity of the above-mentioned resin, so it is possible to suppress unevenness in the film thickness of the resist film and the occurrence of precipitates during spin coating. Details of component (M1) and component (M2) are described in paragraphs

[0218] to

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

[0303] When the solvent further contains components other than the components (M1) and (M2), the content of the components other than the components (M1) and (M2) is preferably 5 to 30 mass % based on the total amount of the solvent.

[0304] The content of the solvent in the resist composition is preferably determined so that the solids concentration is 0.5 to 30 mass %, and more preferably 1 to 20 mass %, which further improves the coatability of the resist composition.

[0305] [Other Additives] The resist composition may further contain at least one selected from the group consisting of a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and a compound that promotes solubility in a developer (for example, a phenolic compound having a molecular weight of 1000 or less, or an alicyclic or aliphatic compound containing a carboxyl group). The "dissolution inhibiting compound" is a compound having a molecular weight of 3000 or less that decomposes under the action of an acid and thereby reduces its solubility in an organic developer.

[0306] The content of the other additives is not particularly limited, but may be 20.0% by mass or less, 10.0% by mass or less, or 5.0% by mass or less, based on the total solid content of the resist composition. Only one type of other additive may be used, or two or more types may be used. When two or more types are used, it is preferable that the total content thereof is within the above-mentioned preferred content range.

[0307] The resist composition may also contain water as an impurity. When water is contained as an impurity, the lower the content of water, the more preferable, but the resist composition may contain 1 to 30,000 ppm by mass of water relative to the entire resist composition. The resist composition may also contain residual monomers as impurities (for example, monomers derived from the raw material monomers used in the synthesis of the resin (P)). When water is contained as an impurity, the lower the content of residual monomers, the more preferable, but the resist composition may contain 1 to 30,000 ppm by mass of water relative to the entire solid content of the resist composition.

[0308] <Actinic ray-sensitive or radiation-sensitive resin composition> The present invention also relates to an actinic ray-sensitive or radiation-sensitive resin composition containing an acid-decomposable resin (P) and a photoacid generator, wherein the acid-decomposable resin (P) contains at least four types of repeating units, one of which is a repeating unit (U1) represented by formula (I) and at least one of which is a repeating unit (U2) represented by formula (II), and the actinic ray-sensitive or radiation-sensitive resin composition (also referred to as "the composition of the present invention") is used to form a pattern by development with an organic processing liquid containing butyl acetate and a hydrocarbon having from 9 to 12 carbon atoms.

[0309]

[0310] In formula (II), R １ represents a hydrogen atom, a halogen atom or an alkyl group, R ２ represents a group that is eliminated by the action of an acid.

[0311] The composition of the present invention is the same as the actinic ray- or radiation-sensitive resin composition used in step (1) of the pattern formation method of the present invention described above. Furthermore, the organic treatment liquid containing butyl acetate and a hydrocarbon having from 9 to 12 carbon atoms is the same as the organic treatment liquid used in step (3) of the pattern formation method of the present invention described above.

[0312] <Method for manufacturing an electronic device> This specification also relates to a method for manufacturing an electronic device, including the above-mentioned pattern formation method, and an electronic device manufactured by this manufacturing method. Preferred embodiments of the electronic device of this specification include those installed in electrical and electronic devices (such as home appliances, office automation (OA), media-related devices, optical devices, and communication devices).

[0313] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

[0314] The various components used in the resist compositions of the examples and comparative examples are shown below.

[0315] <Resin (P)> P-1 to P-32 were used as resins (P). CP-1 to CP-3 were also used as resins other than resin (P). However, in the tables below, CP-1 to CP-3 are listed in the "Resin (P)" column for convenience. P-1 to P-32 and CP-1 to CP-3 contain the repeating units shown in Tables 1 and 2 below in the amounts shown in the tables. In Tables 1 and 2, the "Type" column for the repeating unit represented by formula (II), the third repeating unit, the fourth repeating unit, and the fifth repeating unit lists the corresponding monomer. A "-" in the "Type" and "Content" columns indicates that the repeating unit is not contained. The tables also list the weight average molecular weight (Mw) and dispersity (Mw / Mn) of each resin. The content of each repeating unit is the content ratio (molar ratio) of each repeating unit to all repeating units contained in each resin. In the table, when two or more repeating units represented by formula (II) are contained, the type and content of each are expressed by separating them with " / ". The order of the types and contents separated by " / " corresponds to each other. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the resin were measured by GPC (carrier: tetrahydrofuran (THF)) (in terms of polystyrene). The content of the repeating unit is １３ Measurement was performed by C-NMR (nuclear magnetic resonance).

[0316]

[0317]

[0318] The repeating unit represented by formula (I) is a repeating unit represented by the following structural formula, as described above.

[0319]

[0320] The structural formulae of the monomers corresponding to the repeating units other than the repeating unit represented by formula (I) are shown below.

[0321]

[0322]

[0323]

[0324]

[0325]

[0326] P-14 to P-16 contain repeating units having a group that generates an acid upon irradiation with actinic rays or radiation, and are therefore also photoacid generators. That is, P-14 to P-16 serve as both resins (P) and photoacid generators. However, for convenience, in the table below, P-14 to P-16 are listed only in the "Resin (P)" column and not in the "Photoacid Generator" column. Furthermore, although P-18 also functions as an acid diffusion controller, for convenience, in the table below, P-18 is listed only in the "Resin (P)" column and not in the "Acid Diffusion Controller" column.

[0327] <Photoacid Generator> As the photoacid generator, A-1 to A-17 were used.

[0328]

[0329]

[0330]

[0331] <Acid Diffusion Controller> As the acid diffusion controller, B-1 to B-15 and C-1 to C-5 were used.

[0332]

[0333]

[0334]

[0335] <Hydrophobic Resin> D-1 to D-8 were used as hydrophobic resins. The structural formula of each repeating unit contained in D-1 to D-8 is shown below. For each resin, the content (mass %; corresponding in order from left to right) of each repeating unit relative to the total repeating units contained, the weight average molecular weight (Mw), and the dispersity (Mw / Mn) are shown in Table 3 below. The content of each repeating unit is the content ratio (molar ratio) of each repeating unit relative to the total repeating units contained in each resin. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the resin were measured by GPC (carrier: tetrahydrofuran (THF)) (amounts calculated as polystyrene). The content of the repeating unit was １３ Measurement was performed by C-NMR.

[0336]

[0337]

[0338] <Surfactants> The surfactants used are as follows: E-1: Megafac F176 (manufactured by DIC Corporation, fluorochemical surfactant) E-2: Megafac R08 (manufactured by DIC Corporation, fluorine and silicon surfactant) E-3: PF656 (manufactured by OMNOVA, fluorochemical surfactant)

[0339] <Solvents> The solvents used are as follows: F-1: Propylene glycol monomethyl ether acetate (PGMEA) F-2: Propylene glycol monomethyl ether (PGME) F-3: Propylene glycol monoethyl ether (PGEE) F-4: Cyclohexanone F-5: Cyclopentanone F-6: 2-heptanone F-7: Ethyl lactate F-8: γ-butyrolactone F-9: Propylene carbonate

[0340] <Organic Treatment Liquid> The organic treatment liquids used are shown in Table 4 below. The contents of the first solvent and the second solvent in Table 4 below are the mass ratios of each solvent to the total organic treatment liquid.

[0341]

[0342] <Preparation of Resist Compositions> The components shown in Tables 5 to 6 below were dissolved in the solvents shown in Tables 5 to 6 to prepare solutions, which were then filtered through a polyethylene filter with a pore size of 0.02 μm to prepare resist compositions (Re-1 to Re-36, Re-C1 to Re-C3) with a solids concentration of 2.0 mass %. In Tables 5 to 6, the column "Content (mass %)" indicates the content (mass %) of each component relative to the total solids in the resist composition. The solids refer to components other than the solvent. In Tables 5 to 6, when two or more types of each component were used, the type and content of each component are separated by a " / ". The order of the types and contents separated by a " / " corresponds to the order in which they are listed. In Tables 5 to 6, the "Mixing Ratio" column for "Solvent" indicates the mixing ratio (mass ratio) of each solvent.

[0343]

[0344]

[0345] As mentioned above, P-14 to P-16 also fall under the category of photoacid generators, and P-18 also falls under the category of acid diffusion controller.

[0346] [Pattern Formation and Evaluation by EUV Exposure] <Pattern Formation> An underlayer film-forming composition AL412 (manufactured by Brewer Science) was applied to a silicon wafer having a diameter of 12 inches and baked at 205°C for 60 seconds to form an underlayer film having a thickness of 20 nm. A resist composition shown in Table 7 was applied to the underlayer film and baked at 100°C for 60 seconds to form a resist film having a thickness of 30 nm. Using an EUV exposure device (manufactured by Exitech, Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36), a pattern was irradiated onto the silicon wafer having the resulting resist film so that the average line width of the resulting pattern was 20 nm. Note that a mask with a line size of 20 nm and a line:space ratio of 1:1 was used as the reticle. The exposed resist film was baked at 90° C. for 60 seconds, then developed for 30 seconds with the developer shown in Table 7, and spin-dried to obtain a negative pattern.

[0347] <Resolution Evaluation (Limiting Resolution, nm)> In the above <Pattern Formation>, the exposure was performed at an optimum exposure dose Eop (mJ / cm ２ ) (the exposure dose when a pattern formed using the resist composition reproduces the pattern of the mask used for exposure). Next, a test was conducted to form a line and space pattern by gradually changing the exposure dose from the optimum exposure dose Eop. In this case, the minimum dimension of the pattern that could be resolved without collapsing was determined using a critical dimension scanning electron microscope (SEM (Hitachi, Ltd. S-9380II)), and this was taken as the "resolution (nm)." The smaller the resolution value, the better the resolution. The resolution is preferably 15.0 nm or less, more preferably 13.0 nm or less, and most preferably 11.0 nm or less.

[0348]

[0349] From the above results, it was found that the resist compositions and pattern forming methods used in the examples were excellent in resolution.

[0350] The present invention can provide a pattern forming method and an actinic ray-sensitive or radiation-sensitive resin composition having excellent resolution. The present invention can also provide a method for manufacturing an electronic device including the pattern forming method.

[0351] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2024-093263) filed on June 7, 2024, the contents of which are incorporated herein by reference.

Claims

1. A pattern formation method comprising the steps of: (1) forming a film using an actinic ray- or radiation-sensitive resin composition containing an acid-decomposable resin (P) and a photoacid generator; (2) exposing the film to light; and (3) developing the exposed film with an organic processing liquid, wherein the acid-decomposable resin (P) contains at least four types of repeating units, one of which is a repeating unit (U1) represented by formula (I) and at least one of which is a repeating unit (U2) represented by formula (II), and the organic processing liquid contains butyl acetate and a hydrocarbon having from 9 to 12 carbon atoms. In formula (II), R １ represents a hydrogen atom, a halogen atom or an alkyl group, R ２ represents a group that is eliminated by the action of an acid.

2. The pattern formation method according to claim 1, wherein the repeating unit (U2) is the only repeating unit contained in the acid-decomposable resin (P) that has a group that is cleaved by the action of an acid.

3. The pattern formation method according to claim 1, wherein the photoacid generator contains an iodine atom.

4. The pattern formation method according to claim 1, wherein the photoacid generator is an onium salt, and the onium salt contains a cation having a fluorine atom.

5. The pattern formation method according to claim 1, wherein the photoacid generator is an onium salt, and the onium salt contains an anion having an iodine atom.

6. The pattern forming method according to claim 1, wherein the acid-decomposable resin (P) contains at least one group selected from the group consisting of a polycyclic lactone group and a polycyclic sultone group.

7. The pattern forming method according to claim 1, wherein the acid-decomposable resin (P) contains an alicyclic group having two or more hydroxy groups.

8. The pattern forming method according to claim 1, wherein the acid-decomposable resin (P) contains repeating units having a group that is cleaved by the action of an acid in an amount of more than 50 mol % based on the total repeating units.

9. The pattern forming method according to claim 1, wherein the acid-decomposable resin (P) contains the repeating unit (U1) in an amount of more than 30 mol % based on the total repeating units.

10. An actinic ray-sensitive or radiation-sensitive resin composition containing an acid-decomposable resin (P) and a photoacid generator, wherein the acid-decomposable resin (P) contains at least four types of repeating units, one of which is a repeating unit (U1) represented by formula (I) and at least one of which is a repeating unit (U2) represented by formula (II), and the actinic ray-sensitive or radiation-sensitive resin composition is used to form a pattern by developing with an organic processing liquid containing butyl acetate and a hydrocarbon having from 9 to 12 carbon atoms. In formula (II), R １ represents a hydrogen atom, a halogen atom or an alkyl group, R ２ represents a group that is eliminated by the action of an acid.

11. A method for manufacturing an electronic device, comprising the pattern formation method according to any one of claims 1 to 9.

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