Organic processing liquid

Abstract

To provide a pattern forming method capable of obtaining a pattern excellent in in-plane uniformity of line width.SOLUTION: A pattern forming method including (1) a step of forming a film using an actinic ray-sensitive or radiation-sensitive resin composition including a resin (A) that decomposes by the action of an acid to increase polarity and a compound (B) that generates an acid upon irradiation with actinic rays or radiation, (2) a step of exposing the film, and (3) a step of subjecting the exposed film to at least one of development or rinsing with an organic treatment liquid containing butyl acetate and a hydrocarbon having 11 or more carbon atoms, in which a content of the hydrocarbon having 11 or more carbon atoms in the organic treatment liquid is 1% by mass or more and 35% by mass or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a pattern formation method and an electronic device manufacturing method, and more particularly to an ultra-microlithography process applicable to processes such as the manufacturing process of VLSI (Large Scale Integration) and high-capacity microchips, the manufacturing process of nanoimprint molds, and the manufacturing process of high-density information recording media, as well as other photofabrication processes. [Background technology]

[0002] Traditionally, microfabrication has been performed by lithography using photoresist compositions in the manufacturing process of semiconductor devices such as ICs (Integrated Circuits) and LSIs. In recent years, the increasing integration density of integrated circuits has led to 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 technology 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, chemically amplified resist compositions that are effectively sensitive to various types of radiation and have excellent sensitivity and resolution have been developed.

[0004] For example, Patent Document 1 describes a pattern formation method in which a resist film is developed or washed (rinsed) using an organic processing liquid containing an oxidizing agent within a specific range. Furthermore, Patent Document 2 describes a pattern formation method in which a resist film is formed using a negative-tone chemically amplified resist composition that becomes negative through a crosslinking reaction, and then the resist film is exposed to light and then developed using a developer containing an organic solvent that satisfies specific conditions. Furthermore, Patent Document 3 describes a pattern formation method in which a resist film containing a resin having an acid-decomposable repeating unit that is decomposed by the action of an acid to generate an acid having a pKa in a specific range is exposed to light, and then developed using a developer containing an organic solvent. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2016 / 104565 [Patent Document 2] Japanese Patent Publication No. 2011-065105 [Patent Document 3] International Publication No. 2016 / 158711 Summary of the Invention [Problem to be solved by the invention]

[0006] As described in the aforementioned Patent Documents 1 to 3, it has been known that in pattern formation methods, development or rinsing is performed using an organic solvent. However, the inventors' studies have revealed that there is room for improvement in the in-plane uniformity of the line width of the resulting pattern, particularly when a developer or rinse containing a conventional organic solvent is used for a resist film formed using a polarity conversion resist composition containing an acid-decomposable resin and a photoacid generator.

[0007] Therefore, an object of the present invention is to provide a pattern forming method capable of obtaining a pattern with excellent in-plane uniformity of line width, and a method for manufacturing an electronic device including the pattern forming method. [Means for solving the problem]

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

[0009] [1] (1) forming a film using an actinic ray-sensitive or radiation-sensitive resin composition containing a resin (A) that decomposes under the action of an acid to increase its polarity and a compound (B) that generates an acid upon exposure to actinic rays or radiation; (2) exposing the film to light; (3) A pattern forming method comprising a step of at least one of developing and rinsing the exposed film with an organic processing liquid containing butyl acetate and a hydrocarbon having 11 or more carbon atoms, The pattern formation method, wherein the content of the hydrocarbon having 11 or more carbon atoms in the organic treatment liquid is 1% by mass or more and 35% by mass or less. [2] The pattern formation method according to [1], wherein the hydrocarbon having 11 or more carbon atoms is undecane. [3] The pattern formation method according to [1] or [2], wherein the resin (A) that is decomposed by the action of an acid to increase its polarity comprises at least one selected from the group consisting of a group in which the hydrogen atom of a carboxy group is substituted with a leaving group that is released by the action of an acid, a group in which the hydrogen atom of an alcoholic hydroxyl group is substituted with a leaving group that is released by the action of an acid, and a group in which the hydrogen atom of a phenolic hydroxyl group is substituted with a leaving group that is released by the action of an acid. [4] The pattern forming method according to any one of [1] to [3], wherein the resin (A) that is decomposed by the action of an acid to increase its polarity has a repeating unit represented by the following general formula (AX):

[0010] [ka]

[0011] In the general formula (AX), Xa1 represents a hydrogen atom or an alkyl group. Rx1 to Rx3 each independently represent an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group. Two of Rx1 to Rx3 may be bonded to form a ring. [5] The pattern forming method according to any one of [1] to [4], wherein the resin (A) that is decomposed by the action of an acid to increase its polarity has at least one group selected from the group consisting of a lactone group, a carbonate group, a sultone group, and a cyclic group having a hydroxyl group. [6] The pattern forming method according to any one of [1] to [5], wherein the resin (A) that is decomposed by the action of an acid to increase its polarity has a repeating unit represented by the following general formula (Y):

[0012] [ka]

[0013] In general formula (Y), A represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, or a cyano group. L represents a single bond or a divalent linking group having an oxygen atom. R represents a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an aralkyl group, an alkoxy group, an alkylcarbonyloxy group, an alkylsulfonyloxy group, an alkyloxycarbonyl group, or an aryloxycarbonyl group, and when there are two or more Rs, they may be the same or different. When there are two or more Rs, they may join together to form a ring. a represents an integer of 1 to 3. b represents an integer of 0 to (5-a). [7] The pattern forming method according to any one of [1] to [6], wherein the compound (B) that generates an acid upon irradiation with actinic rays or radiation has a cation represented by the following general formula (ZaI) or a cation represented by the following general formula (ZaII):

[0014] [ka]

[0015] In the general formula (ZaI), R 201 , R 202 , and R 203 each independently represents an organic group. In the general formula (ZaII), R 204 and R 205 each independently represents an organic group. [8] R in the above general formula (ZaI) 201 , R 202 , and R 203 At least one of R in the general formula (ZaII) is an aryl group. 204 and R 205 The pattern forming method according to [7], wherein at least one of the groups is an aryl group. [9] R in the above general formula (ZaI) 201 , R 202 , and R 203 at least one of R in the general formula (ZaII) has an acid-decomposable group, 204 and R 205 The pattern forming method according to [7] or [8], wherein at least one of the above has an acid-decomposable group.

[10] The pattern forming method according to any one of [1] to [9], wherein the compound (B) that generates an acid upon irradiation with actinic rays or radiation has a molecular weight of 250 or more.

[11] The pattern forming method according to any one of [1] to

[10] , wherein the content of the compound (B) that generates an acid upon irradiation with actinic rays or radiation is 10 mass % or more based on the total solid content of the actinic ray-sensitive or radiation-sensitive resin composition.

[12] The pattern forming method according to any one of [1] to

[11] , wherein the actinic ray-sensitive or radiation-sensitive resin composition contains two or more compounds (B) that generate an acid upon irradiation with actinic rays or radiation, or the compound (B) that generates an acid upon irradiation with actinic rays or radiation is at least one selected from the group consisting of the following compound (I) and the following compound (II): Compound (I): A compound having one or more structural moieties X and one or more structural moieties Y, which generates an acid containing a first acidic moiety derived from the structural moiety X and a second acidic moiety derived from the structural moiety Y when irradiated with actinic rays or radiation. Structural site X: Anion site A1 - and cationic moiety M1 + and a structural portion that forms a first acidic site represented by HA1 upon irradiation with actinic rays or radiation. Structural site Y: Anionic site A2 - and cationic moiety M2 + and a structural portion that forms a second acidic site represented by HA2 upon irradiation with actinic rays or radiation. However, compound (I) satisfies the following condition I. Condition I: In the compound (I), the cation moiety M1 in the structural moiety X + and the cationic moiety M2 in the structural moiety Y. + H + The compound PI in which the cationic moiety M1 in the structural moiety X is replaced by + H + and the cationic moiety M2 in the structural moiety Y. + H + and the acid dissociation constant a2 is greater than the acid dissociation constant a1. Compound (II): A compound having two or more of the structural moieties X and one or more of the 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 when irradiated with actinic rays or radiation. Structural site Z: a ​​non-ionic site capable of neutralizing acids

[13] A method for manufacturing an electronic device, comprising the pattern forming method according to any one of [1] to

[12] . [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a pattern forming method capable of obtaining a pattern with excellent in-plane uniformity of line width, and a method for manufacturing an electronic device including the pattern forming method. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below. The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In the present specification, when a group (atomic group) is represented without specifying whether it is substituted or unsubstituted, it encompasses both unsubstituted and substituted groups, unless it is contrary to the spirit of the present invention. For example, the term "alkyl group" encompasses not only unsubstituted alkyl groups (unsubstituted alkyl groups) but also substituted alkyl groups (substituted alkyl groups). Furthermore, in the present specification, the term "organic group" refers to a group containing at least one carbon atom. Unless otherwise specified, the substituent is preferably a monovalent substituent.

[0018] In this specification, "actinic rays" or "radiation" refers to, for example, the bright line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV), X-rays, and electron beams (EB). In this specification, the term "light" means actinic rays or radiation. In this specification, unless otherwise specified, the term "exposure" includes not only exposure using the bright line spectrum of a mercury lamp, far ultraviolet light typified by an excimer laser, extreme ultraviolet light, X-rays, EUV light, and the like, but also drawing using particle beams such as electron beams and ion beams. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0019] 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 "XYZ", Y may be -CO-O- or -O-CO-. In addition, the compound may be "X-CO-OZ" or "XO-CO-Z".

[0020] In this specification, (meth)acrylate refers to acrylate and methacrylate, and (meth)acrylic refers to acrylic and methacrylic. In this specification, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity (hereinafter also referred to as "molecular weight distribution") (Mw / Mn) are defined as polystyrene-equivalent values ​​measured using a Gel Permeation Chromatography (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: refractive index detector).

[0021] In this specification, the acid dissociation constant (pKa) refers to the pKa in an aqueous solution, and specifically, is a value determined by calculation based on a database of Hammett's substituent constants and known literature values ​​using the following software package 1. 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).

[0022] The pKa can also be calculated by molecular orbital calculations. This method is based on the thermodynamic cycle and calculates the pKa of H in aqueous solution. + 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, such as Gaussian 16.

[0023] In this specification, pKa refers to a value calculated using software package 1 based on a database of Hammett's substituent constants and known literature values, as described above. However, if pKa cannot be calculated by this method, a value obtained by Gaussian 16 based on DFT (density functional theory) will be used. In addition, in this specification, pKa refers to "pKa in aqueous solution" as described above, but when pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" will be adopted.

[0024] [Pattern Forming Method] The pattern forming method of the present invention comprises: (1) forming a film using an actinic ray-sensitive or radiation-sensitive resin composition containing a resin (A) that decomposes under the action of an acid to increase its polarity and a compound (B) that generates an acid upon exposure to actinic rays or radiation; (2) exposing the film to light; (3) A pattern forming method comprising a step of at least one of developing and rinsing the exposed film with an organic processing liquid containing butyl acetate and a hydrocarbon having 11 or more carbon atoms, In the pattern formation method, the content of the hydrocarbon having 11 or more carbon atoms in the organic treatment liquid is 1% by mass or more and 35% by mass or less.

[0025] Although the details of the mechanism by which a pattern having excellent in-plane uniformity of line width can be obtained by the pattern forming method of the present invention are not clear, the present inventors speculate as follows. An organic processing solution having a specific composition containing butyl acetate and a hydrocarbon having 11 or more carbon atoms, with the content of the hydrocarbon having 11 or more carbon atoms being 1% by mass or more and 35% by mass or less, has excellent affinity for a film formed from an actinic ray- or radiation-sensitive resin composition containing a resin (A) that decomposes under the action of acid to increase its polarity, and a compound (B) that generates an acid upon irradiation with actinic rays or radiation. Therefore, by performing at least one of development and rinsing using the organic processing solution, the organic processing solution uniformly wets and spreads over the entire wafer, which is thought to improve the in-plane uniformity of line width.

[0026] The procedures for each of the above steps will be described in detail below.

[0027] <Process (1)> Step (1) is a step of forming a film using an actinic ray-sensitive or radiation-sensitive resin composition containing a resin (A) that decomposes under the action of an acid to increase its polarity, and a compound (B) that generates an acid upon irradiation with actinic rays or radiation. The actinic ray-sensitive or radiation-sensitive resin composition used in step (1) is typically a resist composition, and hereinafter the actinic ray-sensitive or radiation-sensitive resin composition is also referred to as a "resist composition." Furthermore, a film formed using the actinic ray-sensitive or radiation-sensitive resin composition is typically a resist film, and hereinafter the film formed using the actinic ray-sensitive or radiation-sensitive resin composition is also referred to as a "resist film." The actinic ray-sensitive or radiation-sensitive resin composition will be described in detail later.

[0028] Step (1) is typically a step of forming a resist film on a substrate using a resist composition.

[0029] An example of a method for forming a resist film on a substrate using a resist composition is a method in which the resist composition is applied onto the substrate. Before coating, the resist composition is preferably filtered as needed. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.05 μm or less, and even more preferably 0.03 μm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

[0030] The resist composition can be applied to a substrate (e.g., silicon, silicon dioxide-coated) such as those used in the manufacture of integrated circuit devices by a suitable application method such as a spinner or coater. Spin application using a spinner is preferred. The rotation speed when spinning using a spinner is preferably 1000 to 3000 rpm (rotations per minute). After coating the resist composition, the substrate may be dried to form a resist film. If necessary, various undercoating films (inorganic films, organic films, anti-reflective films) may be formed under the resist film.

[0031] An example of a drying method is a method of drying by heating. Heating can be performed by means provided in a normal exposure machine and / or developing machine, or may be performed using a hot plate or the like. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, and even more preferably 60 to 600 seconds.

[0032] The thickness of the resist film is not particularly limited, but is preferably 10 to 120 nm, since this allows for the formation of finer patterns with higher precision. In particular, when EUV exposure is used, the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. 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.

[0033] A top coat may be formed on the resist film using a top coat composition. The top coat composition preferably does not mix with the resist film and can be uniformly applied to the upper layer of 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 JP2014-059543A. For example, it is preferable to form a top coat containing a basic compound such as that described in JP 2013-61648 A. Specific examples of the basic compound that the top coat may contain include basic compounds that may be contained in the resist composition. The top coat also preferably contains a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond.

[0034] <Process (2)> Step (2) is a step of exposing the resist film. The exposure method may be a method in which the formed resist film is irradiated 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, preferably far ultraviolet light having 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), F2 excimer laser (157 nm), EUV (13 nm), X-rays, and electron beams.

[0035] After exposure, it is preferable to bake (heat) the film before development, as this promotes the reaction of the exposed areas and improves the sensitivity and pattern shape. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is preferably from 10 to 1000 seconds, more preferably from 10 to 180 seconds, and even more preferably from 30 to 120 seconds. Heating can be carried out by means provided in a normal exposure machine and / or developing machine, and may also be carried out using a hot plate or the like. This step is also called post-exposure baking.

[0036] <Process (3)> Step (3) is a step of at least one of developing and rinsing the resist film exposed in step (2) with an organic processing liquid containing butyl acetate and a hydrocarbon having 11 or more carbon atoms. The content of the hydrocarbon having 11 or more carbon atoms in the organic processing liquid is 1% by mass or more and 35% by mass or less.

[0037] The organic treatment liquid used in step (3) contains butyl acetate and a hydrocarbon having 11 or more carbon atoms. The hydrocarbon having 11 or more carbon atoms is preferably an alkane, more preferably an alkane having 11 to 15 carbon atoms, even more preferably an alkane having 11 to 13 carbon atoms, particularly preferably undecane or dodecane, and most preferably undecane. Note that when structural isomers exist, such as undecane or dodecane, the hydrocarbon having 11 or more carbon atoms may contain the structural isomer. The organic treatment liquid may contain only one type of hydrocarbon having 11 or more carbon atoms, or may contain two or more types of hydrocarbons. The content of hydrocarbons having 11 or more carbon atoms in the organic treatment liquid (the total amount when multiple hydrocarbons having 11 or more carbon atoms are contained) is from 1 to 35% by mass, preferably from 5 to 30% by mass, and more preferably from 10 to 25% by mass, with the entire organic treatment liquid being 100% by mass.

[0038] The organic treatment liquid used in step (3) contains butyl acetate (n-butyl acetate). The content of butyl acetate in the organic treatment liquid is preferably 65% ​​by mass or more and 99% by mass or less, more preferably 70% by mass or more and 95% by mass or less, and even more preferably 75% by mass or more and 90% by mass or less, with the entire organic treatment liquid being 100% by mass.

[0039] The organic treatment liquid may contain other components in addition to butyl acetate and hydrocarbons having 11 or more carbon atoms. Examples of other components include surfactants, antioxidants, and basic compounds. The content of other components in the organic treatment liquid is preferably 0% by mass or more and 5% by mass or less, more preferably 0% by mass or more and 1% by mass or less, even more preferably 0% by mass or more and 0.5% by mass or less, with the entire organic treatment liquid being 100% by mass, and it is particularly preferable for the content to be 0% by mass (i.e., no other components are contained).

[0040] Step (3) is a step of developing and / or rinsing (cleaning) the resist film exposed in step (2) with the organic treatment liquid. In step (3), only development may be performed, only rinsing may be performed, or both development and rinsing may be performed. Below, we will explain the case where development is performed in step (3) (hereinafter, the step of developing using the organic processing liquid will also be referred to as step (3A)), and the case where rinsing is performed in step (3) (hereinafter, the step of rinsing using the organic processing liquid will also be referred to as step (3B)). Step (3) may be a step including only step (3A), or may be a step including only step (3B), or may be a step including steps (3A) and (3B). When step (3) includes steps (3A) and (3B), the organic processing liquid used as the developer in step (3A) and the organic processing liquid used as the rinse liquid in step (3B) may be the same or different. A particularly preferred embodiment of the present invention is an embodiment in which an organic processing liquid containing butyl acetate and undecane, with a mass ratio of "butyl acetate / undecane" of "90 / 10", is used as the rinse liquid.

[0041] [Process (3A)] The case where development is carried out using the organic processing liquid in step (3) (step (3A)) will be described below: In step (3A), the organic processing liquid is used as a developer.

[0042] Examples of development methods include a method in which a substrate is immersed in a tank filled with developer for a certain period of time (dip method), a method in which developer is piled up on the surface of the substrate by surface tension and left stationary for a certain period of time for development (puddle method), a method in which developer is sprayed onto the surface of the substrate (spray method), and a method in which developer is continuously dispensed onto a substrate rotating at a constant speed while a developer dispensing nozzle is scanned at a constant speed (dynamic dispense method). After the development step, a step of stopping the development while replacing the solvent with another solvent may be carried out. The developing 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 preferably from 0 to 50°C, more preferably from 15 to 35°C.

[0043] By carrying out the step (3A), a resist pattern (also simply referred to as a "pattern") is formed. After step (3A), it is preferable to perform rinsing. Rinsing can be performed in step (3B) described below, or can be performed using a rinsing liquid other than the organic processing liquid. The rinse liquid other than the organic treatment liquid is not particularly limited as long as it does not dissolve the pattern, and a solution containing a general organic solvent can be used. The rinse liquid other than the organic treatment liquid 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. Even when rinsing is performed using a rinse liquid other than the organic treatment liquid, the rinsing method can be the same as the rinsing method in step (3B) described below.

[0044] [Process (3B)] The case where development is carried out using the organic processing liquid in step (3) (step (3B)) will be described below: In step (3B), the organic processing liquid is used as a rinse liquid.

[0045] The rinsing method is not particularly limited, and examples thereof include a method in which a rinsing 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 rinsing liquid for a certain period of time (dip method), and a method in which the rinsing liquid is sprayed onto the surface of the substrate (spray method).

[0046] It is preferable to carry out development before carrying out step (3B). Development can be carried out by the above-mentioned step (3A), or can be carried out using a developer other than the above organic processing liquid. As a developer other than the organic processing liquid, it is preferable to use an organic developer. Even when development is carried out using a developer other than the above organic processing liquid, the development method can be the same as the development method in the above-mentioned step (3A).

[0047] The organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents.

[0048] The organic solvents may be mixed in combination with one another, or may be mixed with water or a solvent other than the above. The water content of the developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, and even more preferably less than 10% by mass, and particularly preferably substantially free of water. The content of the organic solvent in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, still more preferably 90% by mass or more and 100% by mass or less, and particularly preferably 95% by mass or more and 100% by mass or less, based on the total amount of the developer.

[0049] The pattern formation method of the present invention may also include a heating step (post-bake) after the rinsing step. This step removes the developer and rinsing solution remaining between and within the pattern. This step also has the effect of annealing the resist pattern and improving the surface roughness of the pattern. The heating step after the rinsing step is usually performed at 40 to 250°C (preferably 90 to 200°C) for usually 10 seconds to 3 minutes (preferably 30 to 120 seconds).

[0050] Alternatively, the substrate may be etched using the formed pattern as a mask. That is, the substrate (or the underlayer film and the substrate) may be processed using the pattern formed in step (3) as a mask to form a pattern on the substrate. The method for processing the substrate (or the underlayer film and the substrate) is not particularly limited, but a method of forming a pattern on the substrate by dry etching the substrate (or the underlayer film and the substrate) using the pattern formed in step (3) as a mask is preferred. The dry etching is preferably oxygen plasma etching.

[0051] The organic processing solution, resist composition, and other materials (e.g., solvent, developer, rinse, 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. There is no particular lower limit, and 0 mass ppt or more is preferred. 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.

[0052] 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.

[0053] 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).

[0054] In addition to filtration, impurities may be removed using an adsorbent, or a combination of 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 0 ppt by mass or more is preferred.

[0055] A conductive compound may be added to an organic processing liquid such as a rinse liquid to prevent breakdown of chemical piping and various parts (filters, O-rings, tubes, etc.) due to static charging and subsequent static discharge. The conductive compound is not particularly limited, but examples include methanol. The amount added is not particularly limited, but in order to maintain favorable development or rinsing properties, it is preferably 10% by mass or less, more preferably 5% by mass or less. There is no particular lower limit, but 0.01% by mass or more is preferred. For example, SUS (stainless steel), or various pipes coated with antistatically treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) can be used for the chemical liquid piping. Similarly, antistatically treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) can be used for the filter and O-ring.

[0056] [Actinic ray-sensitive or radiation-sensitive resin composition] The actinic ray-sensitive or radiation-sensitive resin composition used in the present invention will now be described. The actinic ray-sensitive or radiation-sensitive resin composition (also referred to as a "resist composition") used in the present invention contains a resin (A) that decomposes under the action of an acid to increase its polarity (also referred to as an "acid-decomposable resin" or "resin (A)"), and a compound (B) that generates an acid upon irradiation with actinic rays or radiation (also referred to as a "photoacid generator" or "compound (B)").

[0057] The resist composition is preferably a negative resist composition and is also preferably a resist composition for organic solvent development. The resist composition is typically a chemically amplified resist composition.

[0058] [Acid-decomposable resin (resin (A))] The resist composition contains a resin (A). In the pattern forming method of the present invention, typically, when an organic developer is used as the developer, a negative pattern is suitably formed. The resin (A) usually contains a group that decomposes under the action of an acid to increase its polarity (also referred to as an "acid-decomposable group"), and preferably contains a repeating unit having an acid-decomposable group. As the repeating unit having an acid-decomposable group, in addition to the repeating unit having an acid-decomposable group described below, a repeating unit having an acid-decomposable group containing an unsaturated bond is preferred.

[0059] <Repeating Unit Having an Acid-Decomposable Group> (Repeating unit having an acid-decomposable group) The acid-decomposable group is preferably a group that decomposes under the action of an acid to generate a polar group. The acid-decomposable group preferably has a structure in which a polar group is protected by a leaving group that is released by the action of an acid. That is, the resin (A) preferably has a repeating unit having a group that is decomposed by the action of an acid to generate a polar group. The polarity of the resin having this repeating unit increases under the action of an acid, increasing its solubility in alkaline developers and decreasing its solubility in organic solvents. The polar group is preferably an alkali-soluble group, and examples thereof include acidic groups such as a carboxy group, a phenolic hydroxyl group, a fluorinated alcohol group, a sulfonic acid group, a phosphate group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl)(alkylcarbonyl)methylene group, an (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, as well as alcoholic hydroxyl groups. The polar group is preferably a carboxy group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group.

[0060] Examples of the leaving group that is eliminated by the action of an acid include groups represented by formulae (Y1) to (Y4). Formula (Y1):-C(Rx1)(Rx2)(Rx3) Formula (Y2):-C(=O)OC(Rx1)(Rx2)(Rx3) Formula (Y3):-C(R 36 )(R 37 )(OR 38 ) Formula (Y4):-C(Rn)(H)(Ar)

[0061] In formula (Y1) and formula (Y2), Rx1 to Rx3 each independently represent an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), or an aryl group (monocyclic or polycyclic). When all of Rx1 to Rx3 are alkyl groups (linear or branched), it is preferable that at least two of Rx1 to Rx3 are methyl groups. In particular, it is preferable that Rx1 to Rx3 each independently represent a linear or branched alkyl group, and it is more preferable that Rx1 to Rx3 each independently represent a linear alkyl group. Two of Rx1 to Rx3 may be bonded to form a monocycle or polycycle. The alkyl group represented by Rx1 to Rx3 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. The cycloalkyl groups of Rx1 to Rx3 are preferably monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. The aryl group of Rx1 to Rx3 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. The alkenyl group of Rx1 to Rx3 is preferably a vinyl group. The ring formed by combining two of Rx1 to Rx3 is preferably a cycloalkyl group. The cycloalkyl group formed by combining two of Rx1 to Rx3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, and more preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms. In the cycloalkyl group formed by combining two of Rx1 to Rx3, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. In the group represented by formula (Y1) or formula (Y2), for example, Rx1 is preferably a methyl group or an ethyl group, and Rx2 and Rx3 are bonded to form the above-mentioned cycloalkyl group. When the resist composition is, for example, a resist composition for EUV exposure, it is also preferable that the alkyl group, cycloalkyl group, alkenyl group, or aryl group represented by Rx1 to Rx3, and the ring formed by bonding two of Rx1 to Rx3, further have a fluorine atom or an iodine atom as a substituent.

[0062] 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. R 36 is also preferably a hydrogen atom. The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a group containing a heteroatom such as an oxygen atom and / or a heteroatom such as a carbonyl group. For example, the alkyl group, cycloalkyl group, aryl group, and aralkyl group may have one or more methylene groups replaced with a group containing a heteroatom such as an oxygen atom and / or a heteroatom such as a carbonyl group. Also, R 38 may bond with another substituent on the main chain of the repeating unit to form a ring. 38 The group formed by bonding together the repeating unit and another substituent carried by the main chain of the repeating unit is preferably an alkylene group such as a methylene group. When the resist composition is, for example, a resist composition for EUV exposure, R 36 ~R 38 and a monovalent organic group represented by R 37 and R 38 The ring formed by bonding these groups together preferably further has a fluorine atom or an iodine atom as a substituent.

[0063] Formula (Y3) is preferably a group represented by the following formula (Y3-1).

[0064] [ka]

[0065] Here, L1 and L2 each independently represent 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). M represents a single bond or a divalent linking group. Q 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 combining these (for example, a group combining an alkyl group and a cycloalkyl group). The alkyl and cycloalkyl groups may, for example, have one methylene group replaced with a heteroatom such as an oxygen atom or a group containing a heteroatom such as a carbonyl group. Preferably, one of L1 and L2 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. At least two of Q, M, and L1 may be bonded to form a ring (preferably a 5- or 6-membered ring). From the viewpoint of pattern miniaturization, L2 is preferably a secondary or tertiary alkyl group, 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, Tg (glass transition temperature) and activation energy are increased, thereby ensuring film strength and suppressing fogging.

[0066] When the resist composition is, for example, a resist composition for EUV exposure, the alkyl groups, cycloalkyl groups, aryl groups, and groups combining these represented by L1 and L2 preferably further contain a fluorine atom or an iodine atom as a substituent. Furthermore, the alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups preferably contain a heteroatom such as an oxygen atom in addition to the fluorine atom or iodine atom (i.e., the alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups preferably have, for example, one methylene group replaced with a heteroatom such as an oxygen atom, or a group containing a heteroatom such as a carbonyl group). Furthermore, when the resist composition is, for example, a resist composition for EUV exposure, in the alkyl group which may contain a heteroatom, the cycloalkyl group which may contain a heteroatom, the aryl group which may contain a heteroatom, the amino group, the ammonium group, the mercapto group, the cyano group, the aldehyde group, and groups combining these, represented by Q, the heteroatom is preferably a heteroatom selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom.

[0067] 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. When the resist composition is, for example, a resist composition for EUV exposure, the aromatic ring group represented by Ar and the alkyl group, cycloalkyl group, and aryl group represented by Rn preferably have a fluorine atom and an iodine atom as a substituent.

[0068] In terms of excellent acid decomposition properties of the repeating unit, when a non-aromatic ring is directly bonded to the polar group (or a residue thereof) in the leaving group protecting the polar group, it is also preferable that the ring atom in the non-aromatic ring adjacent to the ring atom directly bonded to the polar group (or a residue thereof) does not have a halogen atom such as a fluorine atom as a substituent.

[0069] The leaving 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.

[0070] The resin (A) preferably contains at least one selected from the group consisting of a group in which the hydrogen atom of a carboxy group is substituted with a leaving group that leaves under the action of an acid, a group in which the hydrogen atom of an alcoholic hydroxyl group is substituted with a leaving group that leaves under the action of an acid, and a group in which the hydrogen atom of a phenolic hydroxyl group is substituted with a leaving group that leaves under the action of an acid.

[0071] The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by formula (A).

[0072] [ka]

[0073] L1 represents a divalent linking group which may have a fluorine atom or an iodine atom, R1 represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom, and R2 represents a leaving group which is eliminated by the action of an acid and which may have a fluorine atom or an iodine atom, provided that at least one of L1, R1, and R2 has a fluorine atom or an iodine atom. L1 represents a divalent linking group which may have a fluorine atom or an iodine atom. Examples of the divalent linking group which may have a fluorine atom or an iodine atom include -CO-, -O-, -S-, -SO-, -SO2-, hydrocarbon groups which may have a fluorine atom or an iodine atom (for example, an alkylene group, a cycloalkylene group, an alkenylene group, an arylene group, etc.), and linking groups in which a plurality of these groups are linked together. Among these, L1 is preferably -CO-, an arylene group, or -arylene group-alkylene group having a fluorine atom or an iodine atom-, and more preferably -CO- or -arylene group-alkylene group having a fluorine atom or an iodine atom-. The arylene group is preferably a phenylene group. The alkylene group may be linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the alkylene group having a fluorine atom or an iodine atom is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0074] R1 represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom. The alkyl group may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the alkyl group having a fluorine atom or an iodine atom is not particularly limited, but is preferably 1 or more, more preferably 1 to 5, and even more preferably 1 to 3. The alkyl group may contain a heteroatom other than a halogen atom, such as an oxygen atom.

[0075] R2 represents a leaving group which is eliminated by the action of an acid and which may have a fluorine atom or an iodine atom. Examples of the leaving group which may have a fluorine atom or an iodine atom include the leaving groups represented by the above formulae (Y1) to (Y4) and which have a fluorine atom or an iodine atom.

[0076] The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by the following general formula (AI).

[0077] [ka]

[0078] In general formula (AI), Xa1 represents a hydrogen atom or an alkyl group. T represents a single bond or a divalent linking group. Rx1 to Rx3 each independently represent an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group. Two of Rx1 to Rx3 may be bonded to form a ring.

[0079] The alkyl group represented by Xa1 may be linear or branched. The alkyl group may have a substituent. Examples of the alkyl group include a methyl group or -CH2-R 11 Examples of such groups include groups represented by R 11 represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, and examples thereof include an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, an acyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, with an alkyl group having 3 or less carbon atoms being preferred, and a methyl group being more preferred. Xa1 is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0080] Examples of the divalent linking group for T include an alkylene group, an aromatic ring group, a -COO-Rt- group, and a -O-Rt- group, where Rt represents an alkylene group or a cycloalkylene group. T is preferably a single bond or a -COO-Rt- group, more preferably a single bond. When T represents a -COO-Rt- group, Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a -CH2- group, a -(CH2)2- group, or a -(CH2)3- group.

[0081] The alkyl groups of Rx1 to Rx3 may be linear or branched. The alkyl groups may have a substituent. The alkyl groups are preferably alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl. The cycloalkyl groups Rx1 to Rx3 may be monocyclic cycloalkyl groups or polycyclic cycloalkyl groups. The cycloalkyl groups may have a substituent. The cycloalkyl groups are preferably monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, or polycyclic cycloalkyl groups such as norbornyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups. The cycloalkyl groups may have, for example, one methylene group substituted with a heteroatom such as an oxygen atom or a sulfur atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. The cycloalkyl groups may have one or more ethylene groups substituted with a vinylene group in the cycloalkane ring. The aryl groups of Rx1 to Rx3 may be monocyclic aryl groups or polycyclic aryl groups. The aryl groups may have a substituent. The aryl groups are preferably aryl groups having 6 to 10 carbon atoms, such as phenyl, naphthyl, and anthryl. The alkenyl groups of Rx1 to Rx3 may be linear or branched. The alkenyl groups may have a substituent. The alkenyl groups are preferably vinyl groups. When two of Rx1 to Rx3 are bonded to form a ring, the ring formed may be monocyclic or polycyclic. The ring formed is preferably a cycloalkyl group. As the cycloalkyl group, monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group are preferred. Polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group are also preferred. Among these, monocyclic cycloalkyl groups having 5 to 6 carbon atoms are preferred. In the cycloalkyl group formed by combining two of Rx1 to Rx3, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom or a sulfur atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

[0082] When each of the above groups has a substituent, the substituent is not particularly limited, and examples thereof include an alkyl group (e.g., having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (e.g., having 1 to 4 carbon atoms), an alkylthio group (e.g., having 1 to 4 carbon atoms), a carboxy group, and an alkoxycarbonyl group (e.g., having 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.

[0083] The repeating unit represented by general formula (AI) is preferably a repeating unit represented by the following general formula (AX).

[0084] [ka]

[0085] In the general formula (AX), Xa1 represents a hydrogen atom or an alkyl group. Rx1 to Rx3 each independently represent an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group. Two of Rx1 to Rx3 may be bonded to form a ring.

[0086] Xa1 in general formula (AX) has the same meaning as Xa1 in general formula (AI) above, and specific examples and preferred ranges are also the same. Rx1 to Rx3 in general formula (AX) have the same meanings as Rx1 to Rx3 in general formula (AI) described above, and specific examples and preferred ranges are also the same.

[0087] As the repeating unit having an acid-decomposable group, a repeating unit represented by the following general formula (AX2) is also preferred.

[0088] [ka]

[0089] In the general formula (AX2), Xa1 represents a hydrogen atom or an alkyl group. Rx1 to Rx3 each independently represent an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group. Two of Rx1 to Rx3 may be bonded to form a ring. Ar represents a divalent aromatic hydrocarbon group.

[0090] Xa1 in general formula (AX2) has the same meaning as Xa1 in general formula (AI) above, and specific examples and preferred ranges are also the same. Rx1 to Rx3 in general formula (AX2) have the same meanings as Rx1 to Rx3 in the above-mentioned general formula (AI), and specific examples and preferred ranges are also the same. In general formula (AX2), Ar is preferably an arylene group, more preferably an arylene group having 6 to 20 carbon atoms, still more preferably an arylene group having 6 to 10 carbon atoms, and particularly preferably a phenylene group. Ar may have a substituent, and examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms), and those having 8 or less carbon atoms are preferred.

[0091] When the resin (A) contains a group in which the hydrogen atom of a phenolic hydroxyl group is substituted with a leaving group that leaves under the action of an acid, the resin (A) preferably has a repeating unit having a structure in which the hydrogen atom of the phenolic hydroxyl group is protected by a group represented by any of the formulae (Y1) to (Y4).

[0092] As a repeating unit containing a group in which the hydrogen atom of a phenolic hydroxyl group is substituted with a leaving group which is eliminated by the action of an acid, a repeating unit represented by the following general formula (AII) is preferred.

[0093] [ka]

[0094] In the general formula (AII), R 61 , R 62 and R 63 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. 62 may be bonded to Ar6 to form a ring, in which case R 62 represents a single bond or an alkylene group. X6 is a single bond, -COO-, or -CONR 64 - represents R 64 represents a hydrogen atom or an alkyl group. L6 represents a single bond or an alkylene group. Ar6 represents an (n+1)-valent aromatic hydrocarbon group, and R 62 When it is bonded to form a ring, it represents an (n+2)-valent aromatic hydrocarbon group. When n≧2, each Y2 independently represents a hydrogen atom or a group which is eliminated by the action of an acid, provided that at least one Y2 represents a group which is eliminated by the action of an acid. The group Y2 that is eliminated by the action of an acid is preferably a group represented by any of the above formulae (Y1) to (Y4). n represents an integer of 1 to 4. Each of the above groups may have a substituent, and examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms), and those having 8 or less carbon atoms are preferred.

[0095] The content of the repeating units having an acid-decomposable group is preferably 15 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total repeating units in the resin (A), and the upper limit thereof is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and particularly preferably 60 mol% or less, based on the total repeating units in the resin (A).

[0096] Specific examples of repeating units having an acid-decomposable group are shown below, but the present invention is not limited thereto. In the formula, Xa1 represents any one of H, CH3, CF3, and CH2OH, and Rxa and Rxb each represent a linear or branched alkyl group having 1 to 5 carbon atoms.

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] [ka]

[0102] [ka]

[0103] (Repeating unit having an acid-decomposable group containing an unsaturated bond) The resin (A) may have a repeating unit having an acid-decomposable group containing an unsaturated bond. The repeating unit having an acid-decomposable group containing an unsaturated bond is preferably a repeating unit represented by formula (B). Formula (B):

[0104] [ka]

[0105] In formula (B), Xb represents a hydrogen atom, a halogen atom, or an alkyl group which may have a substituent. L represents a single bond or a divalent linking group which may have a substituent. Ry1 to Ry3 each independently represent a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an alkenyl group, an alkynyl group, or a monocyclic or polycyclic aryl group, provided that at least one of Ry1 to Ry3 represents an alkenyl group, an alkynyl group, a monocyclic or polycyclic cycloalkenyl group, or a monocyclic or polycyclic aryl group. Two of Ry1 to Ry3 may be bonded to form a monocyclic or polycyclic ring (such as a monocyclic or polycyclic cycloalkyl group or cycloalkenyl group).

[0106] The alkyl group represented by Xb, which may have a substituent, is, for example, a methyl group or -CH2-R 11 Examples of such groups include groups represented by R 11represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, and examples thereof include an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, an acyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, with an alkyl group having 3 or less carbon atoms being preferred, and a methyl group being more preferred. Xb is preferably a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0107] Examples of the divalent linking group for L include a -Rt- group, a -CO- group, a -COO-Rt- group, a -COO-Rt-CO- group, a -Rt-CO- group, and a -O-Rt- group, where Rt represents an alkylene group, a cycloalkylene group, or an aromatic ring group, and an aromatic ring group is preferred. L is preferably a -Rt- group, a -CO- group, a -COO-Rt-CO- group, or a -Rt-CO- group. Rt may have a substituent such as a halogen atom, a hydroxyl group, or an alkoxy group. An aromatic group is preferred.

[0108] The alkyl groups Ry1 to Ry3 are preferably alkyl groups having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The cycloalkyl groups of Ry1 to Ry3 are preferably monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, or polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. The aryl group of Ry1 to Ry3 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. The alkenyl group of Ry1 to Ry3 is preferably a vinyl group. The alkynyl group of Ry1 to Ry3 is preferably an ethynyl group. The cycloalkenyl groups of Ry1 to Ry3 are preferably monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, which have a structure containing a double bond in part thereof. The cycloalkyl group formed by combining two of Ry1 to Ry3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. Also, a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group is preferred. Of these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferred. In the cycloalkyl group or cycloalkenyl group formed by combining two of Ry1 to Ry3, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a carbonyl group, a group containing a heteroatom such as a -SO2- group or a -SO3- group, a vinylidene group, or a combination thereof. Furthermore, in these cycloalkyl groups or cycloalkenyl groups, one or more of the ethylene groups constituting the cycloalkane ring or cycloalkene ring may be replaced with a vinylene group. In the repeating unit represented by formula (B), for example, Ry1 is a methyl group, ethyl group, vinyl group, allyl group, or aryl group, and Ry2 and Ry3 are bonded to form the above-mentioned cycloalkyl group or cycloalkenyl group.

[0109] When each of the above groups has a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxy group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms).The number of carbon atoms in the substituent is preferably 8 or less.

[0110] The repeating unit represented by formula (B) is preferably an acid-decomposable (meth)acrylic acid tertiary ester repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a -CO- group), an acid-decomposable hydroxystyrene tertiary alkyl ether repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a phenyl group), or an acid-decomposable styrene carboxylic acid tertiary ester repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a -Rt-CO- group (Rt is an aromatic group)).

[0111] The content of the repeating units having an acid-decomposable group containing an unsaturated bond is preferably 15 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total repeating units in the resin (A), and the upper limit thereof is preferably 80 mol% or less, more preferably 70 mol% or less, and particularly preferably 60 mol% or less, based on the total repeating units in the resin (A).

[0112] Specific examples of repeating units having an acid-decomposable group containing an unsaturated bond are shown below, but the present invention is not limited to these. In the formula, Xb and L1 represent any of the substituents and linking groups described above, Ar represents an aromatic group, R represents a substituent such as a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR''' or -COOR''': R''' represents an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxy group, R' represents a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an alkenyl group, an alkynyl group, or a monocyclic or polycyclic aryl group, Q represents a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, a -SO2- group, or a -SO3- group, or a vinylidene group, or a combination thereof, and l, n, and m represent integers of 0 or greater.

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] (Repeating unit having a polar group) The resin (A) may have a repeating unit having a polar group. Examples of the polar group include a hydroxyl group, a cyano group, and a carboxyl group. The repeating unit having a polar group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. Furthermore, the repeating unit having a polar group preferably does not have an acid-decomposable group. The alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group or a norbornyl group.

[0118] Specific examples of monomers corresponding to repeating units having a polar group are listed below, but the present invention is not limited to these specific examples. Furthermore, although the following specific examples are described as methacrylic acid ester compounds, they may also be acrylic acid ester compounds.

[0119] [ka]

[0120] Other specific examples of repeating units having a polar group include the structural units disclosed in paragraphs 0415 to 0433 of US Patent Application Publication No. 2016 / 0070167. The resin (A) may contain only one type of repeating unit having a polar group, or may contain two or more types in combination. When the resin (A) contains a repeating unit having a polar group, the content thereof is preferably from 0.1 mol % to 40 mol %, more preferably from 1 to 30 mol %, based on all repeating units in the resin (A).

[0121] The resin (A) may contain repeating units other than the repeating units mentioned above. For example, the resin (A) may contain at least one repeating unit selected from the group consisting of Group A below, and / or at least one repeating unit selected from the group consisting of Group B below. Group A: A group consisting of the following repeating units (20) to (29). (20) A repeating unit having an acid group, as described below (21) A repeating unit having a fluorine atom or an iodine atom, as described below. (22) A repeating unit having a lactone group, a sultone group, or a carbonate group, as described below. (23) A repeating unit having a photoacid generating group, which will be described later (24) A repeating unit represented by formula (V-1) or formula (V-2) described below: (25) A repeating unit represented by formula (A) described below (26) A repeating unit represented by formula (B) described below (27) A repeating unit represented by formula (C) described below (28) A repeating unit represented by formula (D) described below (29) A repeating unit represented by formula (E) described below Group B: A group consisting of the following repeating units (30) to (32). (30) A repeating unit having at least one group selected from a lactone group, a sultone group, a carbonate group, a hydroxyl group, a cyano group, and an alkali-soluble group, as described below. (31) A repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposition, as described below. (32) A repeating unit represented by formula (III) described below, which does not have either a hydroxyl group or a cyano group.

[0122] The resin (A) preferably has an acid group, and as described below, preferably contains a repeating unit having an acid group. The definition of the acid group will be explained later together with preferred embodiments of the repeating unit having an acid group. When the resin (A) has an acid group, the interaction between the resin (A) and the acid generated from the compound (B) is more excellent. As a result, the diffusion of the acid is further suppressed, and the cross-sectional shape of the formed pattern can become more rectangular.

[0123] When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV, the resin (A) preferably has at least one repeating unit selected from the group consisting of Group A above. Furthermore, when the resist composition is used as an actinic ray- or radiation-sensitive resin composition for EUV, the resin (A) preferably contains at least one of a fluorine atom and an iodine atom. When the resin (A) contains both a fluorine atom and an iodine atom, the resin (A) may have one repeating unit containing both a fluorine atom and an iodine atom, or the resin (A) may contain both a repeating unit containing a fluorine atom and a repeating unit containing an iodine atom. Furthermore, when the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV, it is also preferable that the resin (A) has a repeating unit having an aromatic group. When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF, the resin (A) preferably has at least one repeating unit selected from the group consisting of Group B above. When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF, it is preferable that the resin (A) contains neither fluorine atoms nor silicon atoms. Furthermore, when the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF, it is preferable that the resin (A) does not have an aromatic group.

[0124] Resin (A) preferably has at least one selected from the group consisting of a lactone group, a carbonate group, a sultone group, and a cyclic group having a hydroxyl group. Lactone groups, carbonate groups, and sultone groups will be described later. The cyclic group having a hydroxyl group is preferably an alicyclic group having a hydroxyl group, and specific examples include those exemplified in the repeating unit having an acid group described later.

[0125] <Repeating Unit Having an Acid Group> The resin (A) preferably has a repeating unit having an acid group. The acid group is preferably an acid group having a pKa of not more than 13. The acid dissociation constant of the acid group is preferably not more than 13, more preferably 3 to 13, and even more preferably 5 to 10, as described above. When the resin (A) has an acid group with a pKa of 13 or less, the content of the acid group in the resin (A) is not particularly limited, but is often 0.2 to 6.0 mmol / g. Among these, 0.8 to 6.0 mmol / g is preferred, 1.2 to 5.0 mmol / g is more preferred, and 1.6 to 4.0 mmol / g is even more preferred. When the acid group content is within the above range, development proceeds well, and the formed pattern shape is excellent, and the resolution is also excellent. The acid group is preferably, for example, a carboxy group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group. In addition, one or more (preferably one to two) fluorine atoms of the hexafluoroisopropanol group may be substituted with a group other than a fluorine atom (such as an alkoxycarbonyl group). The acid group thus formed, -C(CF3)(OH)-CF2-, is also preferred. In addition, one or more fluorine atoms may be substituted with a group other than a fluorine atom to form a ring containing -C(CF3)(OH)-CF2-. The repeating unit having an acid group is preferably a repeating unit different from the repeating unit having a structure in which a polar group is protected with a leaving group that is released by the action of an acid, and a repeating unit having a lactone group, a sultone group, or a carbonate group, which will be described later.

[0126] The repeating unit having an acid group may have a fluorine atom or an iodine atom.

[0127] Examples of the repeating unit having an acid group include the following repeating units.

[0128] [ka]

[0129] The repeating unit having an acid group is preferably a repeating unit represented by the following formula (Y). The resin (A) preferably has a repeating unit represented by the following general formula (Y).

[0130] [ka]

[0131] In general formula (Y), A represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, or a cyano group. L represents a single bond or a divalent linking group having an oxygen atom. R represents a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an aralkyl group, an alkoxy group, an alkylcarbonyloxy group, an alkylsulfonyloxy group, an alkyloxycarbonyl group, or an aryloxycarbonyl group, and when there are multiple Rs, they may be the same or different. When there are multiple Rs, they may combine with each other to form a ring. R is preferably a hydrogen atom. a represents an integer of 1 to 3. b represents an integer of 0 to (5-a).

[0132] In general formula (Y), R is preferably a hydrogen atom, and L is preferably a single bond.

[0133] Examples of repeating units having an acid group are shown below: wherein a represents 1 or 2.

[0134] [ka]

[0135] [ka]

[0136] [ka]

[0137] Among the above repeating units, the repeating units specifically described below are preferred: In the formula, R represents a hydrogen atom or a methyl group, and a represents 2 or 3.

[0138] [ka]

[0139] [ka]

[0140] The content of the repeating units having an acid group is preferably 10 mol% or more, more preferably 15 mol% or more, based on all repeating units in the resin (A), and the upper limit thereof is preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less, based on all repeating units in the resin (A).

[0141] <Repeating Unit Having a Fluorine Atom, a Bromine Atom, or an Iodine Atom> The resin (A) may contain a repeating unit having a fluorine atom, a bromine atom, or an iodine atom, in addition to the above-mentioned <repeating unit having an acid-decomposable group> and <repeating unit having an acid group>. Furthermore, the <repeating unit having a fluorine atom, a bromine atom, or an iodine atom> referred to here is preferably different from other types of repeating units belonging to Group A, such as the <repeating unit having a lactone group, a sultone group, or a carbonate group> and the <repeating unit having a photoacid-generating group> described below.

[0142] The repeating unit having a fluorine atom, a bromine atom or an iodine atom is preferably a repeating unit represented by formula (C).

[0143] [ka]

[0144] L5 represents a single bond or an ester group. R9 represents a hydrogen atom or an alkyl group which may have a fluorine atom, a bromine atom or an iodine atom. R 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 which is a combination of these.

[0145] Examples of repeating units having a fluorine atom or an iodine atom are shown below.

[0146] [ka]

[0147] The content of repeating units having a fluorine atom, a bromine atom, or an iodine atom is preferably 0 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on all repeating units in the resin (A), and the upper limit thereof is preferably 50 mol% or less, more preferably 45 mol% or less, and even more preferably 40 mol% or less, based on all repeating units in the resin (A). As mentioned above, the repeating units having a fluorine atom, a bromine atom, or an iodine atom do not include <repeating units having an acid-decomposable group> and <repeating units having an acid group>. Therefore, the content of the repeating units having a fluorine atom, a bromine atom, or an iodine atom also refers to the content of repeating units having a fluorine atom, a bromine atom, or an iodine atom excluding <repeating units having an acid-decomposable group> and <repeating units having an acid group>.

[0148] The total content of repeating units containing at least one of a fluorine atom, a bromine atom, and an iodine atom in the repeating units of the resin (A) is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, and particularly preferably 40 mol% or more, based on all repeating units of the resin (A). There is no particular upper limit, but it is, for example, 100 mol% or less based on all repeating units of the resin (A). Examples of the repeating unit containing at least one of a fluorine atom, a bromine atom, and an iodine atom include a repeating unit having a fluorine atom, a bromine atom, or an iodine atom and an acid-decomposable group, a repeating unit having a fluorine atom, a bromine atom, or an iodine atom and an acid group, and a repeating unit having a fluorine atom, a bromine atom, or an iodine atom.

[0149] <Repeating Unit Having at Least One Group Selected from Lactone Group, Sultone Group, Carbonate Group, Hydroxyl Group, Cyano Group, and Alkali-Soluble Group> The resin (A) may have a repeating unit having at least one group selected from a lactone group, a sultone group, a carbonate group, a hydroxyl group, a cyano group, and an alkali-soluble group. First, a repeating unit having at least one selected from the group consisting of a lactone group, a sultone group, and a carbonate group (hereinafter also collectively referred to as a "repeating unit having a lactone group, a sultone group, or a carbonate group") will be described. It is also preferred that the repeating unit having a lactone group, a sultone group, or a carbonate group does not have a hydroxyl group or an acid group such as a hexafluoropropanol group.

[0150] The lactone group or sultone group may have a lactone structure or a sultone structure. The lactone structure or the sultone structure is preferably a 5- to 7-membered cyclic lactone structure or a 5- to 7-membered cyclic sultone structure. Among these, a 5- to 7-membered cyclic lactone structure fused with another ring structure to form a bicyclo structure or a spiro structure, or a 5- to 7-membered cyclic sultone structure fused with another ring structure to form a bicyclo structure or a spiro structure, is more preferred. Resin (A) preferably has a repeating unit having a lactone group or sultone group formed by removing one or more hydrogen atoms from a ring member atom of a lactone structure represented by any one of the following formulae (LC1-1) to (LC1-21) or a sultone structure represented by any one of the following formulae (SL1-1) to (SL1-3). Furthermore, the lactone group or sultone group may be directly bonded to the main chain, for example, the ring atoms of the lactone group or sultone group may constitute the main chain of the resin (A).

[0151] [ka]

[0152] The lactone structure or sultone structure portion may have a substituent (Rb2). Preferred examples of the substituent (Rb2) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, a carboxy group, a halogen atom, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or greater, multiple Rb2s may be different from each other, or multiple Rb2s may be bonded to each other to form a ring.

[0153] Examples of repeating units having a group containing a lactone structure represented by any one of formulas (LC1-1) to (LC1-21) or a sultone structure represented by any one of formulas (SL1-1) to (SL1-3) include repeating units represented by the following formula (AI):

[0154] [ka]

[0155] In formula (AI), Rb0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferred substituents that the alkyl group of Rb0 may have include a hydroxyl group and a halogen atom. Examples of the halogen atom of Rb0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb0 is preferably a hydrogen atom or a methyl group. Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxy group, or a divalent group combining these. Among these, a single bond or a linking group represented by -Ab1-CO2- is preferred. Ab1 represents 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 represents a group obtained by removing one hydrogen atom from a ring member atom of a lactone structure represented by any one of formulae (LC1-1) to (LC1-21), or a group obtained by removing one hydrogen atom from a ring member atom of a sultone structure represented by any one of formulae (SL1-1) to (SL1-3).

[0156] 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.

[0157] The carbonate group is preferably a cyclic carbonate group. The repeating unit having a cyclic carbonate group is preferably a repeating unit represented by the following formula (A-1).

[0158] [ka]

[0159] In formula (A-1), R A 1 represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably a methyl group). n represents an integer of 0 or greater. R A 2 represents a substituent. When n is 2 or more, multiple R A 2 may be the same or different. A represents a single bond or a divalent linking group. The divalent linking group is preferably 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 carboxy group, or a divalent group formed by combining these groups. Z represents an atomic group which forms a monocyclic or polycyclic ring together with the group represented by -O-CO-O- in the formula.

[0160] Examples of repeating units having a lactone group, a sultone group, or a carbonate group are shown below.

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] Next, the repeating unit having a hydroxyl group or a cyano group will be described. The resin (A) may contain a repeating unit having a hydroxyl group or a cyano group, which improves the adhesion to the substrate and the affinity for the developer. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The repeating unit having a hydroxyl group or a cyano group preferably does not have an acid-decomposable group. Examples of the repeating unit having a hydroxyl group or a cyano group include those described in paragraphs

[0081] to

[0084] of JP 2014-98921 A.

[0165] Next, the repeating unit having an alkali-soluble group will be described. The resin (A) may have a repeating unit having an alkali-soluble group. Examples of alkali-soluble groups include carboxy groups, sulfonamide groups, sulfonylimide groups, bisulfonylimide groups, and aliphatic alcohols substituted at the α-position with an electron-withdrawing group (e.g., hexafluoroisopropanol groups), with carboxy groups being preferred. Resin (A) containing a repeating unit having an alkali-soluble group enhances resolution in contact hole applications. Examples of repeating units having an alkali-soluble group include those described in paragraphs

[0085] and

[0086] of JP 2014-98921 A.

[0166] The content of repeating units having at least one group selected from lactone, sultone, carbonate, hydroxyl, cyano, and alkali-soluble groups is preferably 1 mol% or more, more preferably 10 mol% or more, based on all repeating units in resin (A), and the upper limit is preferably 85 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and particularly preferably 60 mol% or less, based on all repeating units in resin (A).

[0167] <Repeating Unit Having a Photoacid-Generating Group> The resin (A) may contain, as a repeating unit other than those mentioned above, a repeating unit having a group that generates an acid upon irradiation with actinic rays or radiation (hereinafter also referred to as a "photoacid-generating group"). In this case, the repeating unit having the photoacid generating group can be considered to correspond to the above-mentioned photoacid generator (B). An example of such a repeating unit is a repeating unit represented by the following formula (4).

[0168] [ka]

[0169] R 41 represents a hydrogen atom or a methyl group. 41 represents a single bond or a divalent linking group. 42 represents a divalent linking group. 40represents a structural moiety that is decomposed by irradiation with actinic rays or radiation to generate an acid in the side chain. Examples of repeating units having a photoacid generating group are shown below.

[0170] [ka]

[0171] Other 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.

[0172] The content of the repeating unit having a photoacid generating group is preferably 1 mol% or more, more preferably 5 mol% or more, based on all repeating units in the resin (A), and the upper limit thereof is preferably 40 mol% or less, more preferably 35 mol% or less, and even more preferably 30 mol% or less, based on all repeating units in the resin (A).

[0173] <Repeating unit represented by formula (V-1) or the following formula (V-2)> The resin (A) may have a repeating unit represented by the following formula (V-1) or the following formula (V-2). The repeating units represented by the following formula (V-1) and the following formula (V-2) are preferably repeating units different from the repeating units described above.

[0174] [ka]

[0175] During the ceremony, R6 and R7 each independently represent a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR or -COOR: R is an alkyl group or a fluorinated alkyl group having 1 to 6 carbon atoms), or a carboxy group. The alkyl group is preferably a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. n3 represents an integer of 0 to 6. n4 represents an integer of 0 to 4. X4 is a methylene group, an oxygen atom, or a sulfur atom. Examples of the repeating unit represented by formula (V-1) or (V-2) are shown below. 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.

[0176] <Repeating units for reducing main chain mobility> Resin (A) preferably has a high glass transition temperature (Tg) from the viewpoint of suppressing excessive diffusion of generated acid or pattern collapse during development. Tg is preferably higher than 90°C, more preferably higher than 100°C, even more preferably higher than 110°C, and particularly preferably higher than 125°C. Note that an excessively high Tg leads to a decrease in the dissolution rate in a developer, so Tg is preferably 400°C or lower, more preferably 350°C or lower. In this specification, the glass transition temperature (Tg) of a polymer such as resin (A) (hereinafter referred to as "Tg of a repeating unit") is calculated by the following method. First, the Tg of a homopolymer consisting of each repeating unit contained in the polymer is calculated using the Bicerano method. Next, the mass proportion (%) of each repeating unit relative to all repeating units in the polymer is calculated. Next, the Tg for each mass proportion is calculated using the Fox formula (described in Materials Letters 62 (2008) 3152, etc.), and these values ​​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.).

[0177] In order to increase the Tg of the resin (A) (preferably to make the Tg exceed 90°C), it is preferable to reduce the mobility of the main chain of the resin (A). Methods for reducing the mobility of the main chain of the resin (A) include the following methods (a) to (e). (a) Introduction of bulky substituents into the main chain (b) Introduction of multiple substituents into the main chain (c) Introduction of a substituent group that induces interactions between resins (A) near the main chain (d) Main chain formation in a cyclic structure (e) Linking of cyclic structures to the main chain The resin (A) preferably has a repeating unit that exhibits a homopolymer Tg of 130° C. or higher. The repeating units exhibiting a homopolymer Tg of 130° C. or higher are not particularly limited as long as they are repeating units exhibiting a homopolymer Tg of 130° C. or higher as calculated by the Bicerano method. Depending on the type of functional group in the repeating units represented by formulas (A) to (E) described below, they may be considered as repeating units exhibiting a homopolymer Tg of 130° C. or higher.

[0178] (Repeating unit represented by formula (A)) One example of a specific means for achieving the above (a) is to introduce a repeating unit represented by formula (A) into resin (A).

[0179] [ka]

[0180] Formula (A), R Arepresents a group containing a polycyclic structure. x represents a hydrogen atom, a methyl group, or an ethyl group. The group containing a polycyclic structure is a group containing a plurality of ring structures, and the plurality of ring structures may or may not be condensed. Specific examples of the repeating unit represented by formula (A) include those described in paragraphs

[0107] to

[0119] of WO 2018 / 193954.

[0181] (Repeating unit represented by formula (B)) One example of a specific means for achieving the above (b) is a method of introducing a repeating unit represented by formula (B) into resin (A).

[0182] [ka]

[0183] In formula (B), R b1 ~R b4 each independently represents a hydrogen atom or an organic group, R b1 ~R b4 At least two of these represent organic groups. In addition, when at least one of the organic groups is a group in which a ring structure is directly linked to the main chain in the repeating unit, the types of the other organic groups are not particularly limited. Furthermore, when none of the organic groups has a ring structure directly connected to the main chain in the repeating unit, at least two of the organic groups are substituents having three or more constituent atoms excluding hydrogen atoms. Specific examples of the repeating unit represented by formula (B) include those described in paragraphs

[0113] to

[0115] of WO 2018 / 193954.

[0184] (Repeating unit represented by formula (C)) One example of a specific means for achieving the above (c) is a method of introducing a repeating unit represented by formula (C) into resin (A).

[0185] [ka]

[0186] In formula (C), R c1 ~R c4 each independently represents a hydrogen atom or an organic group, R c1 ~R c4 At least one of the groups is a group containing a hydrogen-bonding hydrogen atom within three atoms from the main chain carbon. In particular, in order to induce interaction between the main chains of the resin (A), it is preferable to have a hydrogen-bonding hydrogen atom within two atoms (closer to the main chain). Specific examples of the repeating unit represented by formula (C) include those described in paragraphs

[0119] to

[0121] of WO 2018 / 193954.

[0187] (Repeating unit represented by formula (D)) One example of a specific means for achieving the above (d) is to introduce a repeating unit represented by formula (D) into resin (A).

[0188] [ka]

[0189] In formula (D), "cylic" represents a group that forms a main chain with a cyclic structure. The number of atoms constituting the ring is not particularly limited. Specific examples of the repeating unit represented by formula (D) include those described in paragraphs

[0126] to

[0127] of WO 2018 / 193954.

[0190] (Repeating unit represented by formula (E)) One example of a specific means for achieving the above (e) is to introduce a repeating unit represented by formula (E) into resin (A).

[0191] [ka]

[0192] In formula (E), each Re independently represents a hydrogen atom or an organic group, such as an optionally substituted alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. "Cylic" refers to a cyclic group containing carbon atoms in the main chain. There are no particular restrictions on the number of atoms contained in the cyclic group. Specific examples of the repeating unit represented by formula (E) include those described in paragraphs

[0131] to

[0133] of WO 2018 / 193954.

[0193] <Repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposition> Resin (A) may have an alicyclic hydrocarbon structure and a repeating unit that is not acid-decomposable. This reduces the elution of low-molecular-weight components from the resist film into the immersion liquid during immersion exposure. Examples of such a repeating unit include repeating units derived from 1-adamantyl(meth)acrylate, diamantyl(meth)acrylate, tricyclodecanyl(meth)acrylate, or cyclohexyl(meth)acrylate.

[0194] <Repeating unit represented by formula (III) having neither a hydroxyl group nor a cyano group> The resin (A) may have a repeating unit represented by formula (III) that has neither a hydroxyl group nor a cyano group.

[0195] [ka]

[0196] In formula (III), R5 represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group. Ra represents a hydrogen atom, an alkyl group, or a -CH2-O-Ra2 group, where Ra2 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-A No. 2014-98921.

[0197] <Other repeating units> Furthermore, the resin (A) may have a repeating unit other than the repeating units described above. For example, the resin (A) may have a repeating unit selected from the group consisting of a repeating unit having an oxathiane ring group, a repeating unit having an oxazolone ring group, a repeating unit having a dioxane ring group, and a repeating unit having a hydantoin ring group. Examples of such repeating units are shown below.

[0198] [ka]

[0199] In addition to the repeating structural units described above, the resin (A) may have various repeating structural units for the purpose of adjusting dry etching resistance, suitability for a standard developer, substrate adhesion, resist profile, resolution, heat resistance, sensitivity, and the like.

[0200] It is preferable that all of the repeating units of the resin (A) be composed of repeating units derived from a compound having an ethylenically unsaturated bond (particularly when the composition is used as an actinic ray- or radiation-sensitive resin composition for ArF). It is also particularly preferable that all of the repeating units be composed of (meth)acrylate repeating units. In this case, any of the repeating units may be used, all of which are methacrylate repeating units, all of which are acrylate repeating units, or all of which are a mixture of methacrylate repeating units and acrylate repeating units, and it is preferable that the acrylate repeating units account for 50 mol % or less of all the repeating units.

[0201] The resin (A) can be synthesized by a conventional method (for example, radical polymerization). The weight average molecular weight of the resin (A), as measured by GPC in terms of polystyrene, is preferably 30,000 or less, more preferably from 1,000 to 30,000, more preferably from 3,000 to 30,000, and even more preferably from 5,000 to 15,000. The polydispersity (molecular weight distribution) of the resin (A) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0. The smaller the polydispersity, the better the resolution and resist shape, and further the smoother the sidewalls of the resist pattern and the better the roughness.

[0202] In the resist composition, the content of the resin (A) is preferably from 40.0 to 99.9 mass %, and more preferably from 60.0 to 90.0 mass %, based on the total solid content of the composition. The resin (A) may be used alone or in combination of two or more.

[0203] [Solvent (F)] The resist composition preferably contains a solvent (preferably an organic 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).

[0204] Details of the components (M1) and (M2) are described in paragraphs

[0218] to

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

[0205] 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 % relative to the total amount of the solvent.

[0206] The content of the solvent in the resist composition is preferably set 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. The solid content means all components other than the solvent.

[0207] [Compound (B) that generates an acid upon exposure to actinic rays or radiation (photoacid generator)] The resist composition contains a compound (B) (photoacid generator) that generates an acid upon irradiation with actinic rays or radiation.

[0208] The compound (B) may be in the form of a low molecular weight compound, or may be incorporated into a part of a polymer (for example, the above-mentioned resin (A)). In addition, the form of a low molecular weight compound and the form of being incorporated into a part of a polymer (for example, the above-mentioned resin (A)) may be used in combination. When compound (B) is in the form of a low molecular weight compound, the molecular weight of compound (B) is preferably 3000 or less, more preferably 2000 or less, and even more preferably 1000 or less. There is no particular lower limit, but a molecular weight of 100 or more is preferred. When the compound (B) is in a form in which it is incorporated into a part of a polymer, it may be incorporated into a part of the resin (A) or into a resin different from the resin (A). The compound (B) is preferably a low molecular weight compound.

[0209] Examples of the compound (B) include "M + X - The compound is preferably a compound that generates an organic acid upon exposure to light. 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.), carbonylsulfonylimide acids, bis(alkylsulfonyl)imide acids, and tris(alkylsulfonyl)methide acids.

[0210] The molecular weight of the acid generated by compound (B) is preferably 240 or more, more preferably 250 or more, even more preferably 260 or more, particularly preferably 270 or more, and most preferably 280 or more.

[0211] <Organic cation> "M + X - In the compound represented by ", M + represents an organic cation. The structure of the organic cation is not particularly limited, and the valence of the organic cation may be monovalent or divalent or higher. The organic cation is preferably a cation represented by the following general formula (ZaI) (hereinafter also referred to as "cation (ZaI)") or a cation represented by the following general formula (ZaII) (hereinafter also referred to as "cation (ZaII)"):

[0212] [ka]

[0213] In the general formula (ZaI), R 201 , R 202 , and R 203 each independently represents an organic group. In the general formula (ZaII), R 204 and R 205 each independently represents an organic group. The above general formulae (ZaI) and (ZaII) will be described in detail below. 201 , R 202 , and R 203 At least one of R in the general formula (ZaII) is an aryl group. 204 and R 205 It is preferable that at least one of the following is an aryl group. The aryl group may have a substituent, and the substituent is preferably a halogen atom (preferably a fluorine atom or an iodine atom) or an organic group. In addition, R in the above general formula (ZaI) 201 , R 202, and R 203 at least one of R in the general formula (ZaII) has an acid-decomposable group, 204 and R 205 It is also preferable that at least one of R in the general formula (ZaI) has an acid-decomposable group. The acid-decomposable group is the same as that in the resin (A). 201 , R 202 , and R 203 In the embodiment in which at least one of R has an acid-decomposable group, 201 , R 202 , and R 203 At least one of R in the above general formula (ZaII) is preferably an aryl group substituted with an organic group containing an acid-decomposable group. 204 and R 205 In the embodiment in which at least one of R has an acid-decomposable group, 204 and R 205 At least one of these is preferably an aryl group substituted with an organic group containing an acid-decomposable group.

[0214] The cation (ZaI) will be explained. R 201 , R 202 , and R 203 The number of carbon atoms in the organic group represented by R is usually 1 to 30, and 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 (such as butylene and pentylene groups) and -CH2-CH2-O-CH2-CH2-.

[0215] Suitable embodiments of the organic cation in formula (ZaI) include the cation (ZaI-1), cation (ZaI-2), the organic cation represented by formula (ZaI-3b) (cation (ZaI-3b)), and the organic cation represented by formula (ZaI-4b) (cation (ZaI-4b)), which will be described later.

[0216] First, the cation (ZaI-1) will be explained. The cation (ZaI-1) is R in the above formula (ZaI). 201 ~R 203 is an arylsulfonium cation, in which at least one of the groups is an aryl group. The arylsulfonium cation is R 201 ~R 203 All of R may be aryl groups, or 201 ~R 203 A part of the group may be an aryl group, and the remainder may be an alkyl group or a cycloalkyl group. Also, R 201 ~R 203 one of which is an aryl group, and R 201 ~R 203 The remaining two of R may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. 201 ~R 203 Examples of groups formed by combining two of these include alkylene groups in which one or more methylene groups may be substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and / or a carbonyl group (e.g., butylene group, pentylene group, and -CH2-CH2-O-CH2-CH2-). Examples of arylsulfonium cations include triarylsulfonium cations, diarylalkylsulfonium cations, aryldialkylsulfonium cations, diarylcycloalkylsulfonium cations, and aryldicycloalkylsulfonium cations.

[0217] The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, a sulfur atom, or the like. 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 that the arylsulfonium cation optionally has 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.

[0218] R 201 ~R 203 The substituents that the aryl group, alkyl group, and cycloalkyl group may have are each independently preferably an alkyl group (e.g., having 1 to 15 carbon atoms), a cycloalkyl group (e.g., having 3 to 15 carbon atoms), an aryl group (e.g., having 6 to 14 carbon atoms), an alkoxy group (e.g., having 1 to 15 carbon atoms), a cycloalkylalkoxy group (e.g., having 1 to 15 carbon atoms), a halogen atom (e.g., fluorine and iodine), a hydroxyl group, a carboxy group, an ester group, a sulfinyl group, a sulfonyl group, an alkylthio group, or a phenylthio group. The above-mentioned substituent may further have a substituent if possible, and it is also preferred that the above-mentioned 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 are combined in any desired manner to form an acid-decomposable group. The acid-decomposable group is intended to be a group that decomposes under the action of an acid to generate a polar group, and preferably has a structure in which the polar group is protected with a leaving group that is released under the action of an acid. The polar group and leaving group are as described above.

[0219] Next, the cation (ZaI-2) will be explained. The cation (ZaI-2) is R in formula (ZaI). 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. R 201 ~R 203 The organic group having no aromatic ring as the aromatic ring generally has 1 to 30 carbon atoms, and preferably has 1 to 20 carbon atoms. R 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.

[0220] R 201 ~R 203 Examples of the alkyl group and cycloalkyl group include a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl), and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl). R 201 ~R 203 may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. Also, R 201 ~R 203 It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0221] Next, the cation (ZaI-3b) will be explained. The cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).

[0222] [ka]

[0223] In the formula (ZaI-3b), R 1c ~R 5c 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. R 6c and R 7c 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. R x and R y 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. Also, R 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.

[0224] 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.

[0225] 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 include alkylene groups such as butylene and pentylene, in which the methylene group may be substituted with a heteroatom such as an oxygen atom. R 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.

[0226] R 1c ~R 5c , R 6c , R 7c , R x , R y , and R 1c ~R 5c Two or more of the following, R 5c and R 6c , R 6c and R 7c , R 5c and R x , and R x and R y The ring formed by bonding together may have a substituent.

[0227] Next, the cation (ZaI-4b) will be explained. The cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).

[0228] [ka]

[0229] In the formula (ZaI-4b), l represents an integer of 0 to 2. r represents an integer of 0 to 8. R 13 represents a hydrogen atom, a halogen atom (for example, a fluorine atom or an iodine atom), a hydroxyl group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxy 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 (e.g., 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 groups are present, each independently represents the above group such as a hydroxyl group. R 15 Each of R 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 bond together to form a ring structure. 15 The ring formed by bonding together may have a substituent.

[0230] In formula (ZaI-4b), R 13 , R 14 , and R 15The alkyl group may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1 to 10. The alkyl group is more preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like. Also, R 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.

[0231] Next, formula (ZaII) will be explained. In formula (ZaII), R 204 and R 205 each independently represents an organic group, and preferably represents an aryl group, an alkyl group, or a cycloalkyl group. R 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 may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, a sulfur atom, etc. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. R 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 (for example, a methyl group, an ethyl group, a propyl group, a butyl group, or a pentyl group), or a cycloalkyl group having 3 to 10 carbon atoms (for example, a cyclopentyl group, a cyclohexyl group, or a norbornyl group).

[0232] 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.

[0233] M + Specific examples of the organic cation represented by the formula (I) are shown below, but the present invention is not limited to these.

[0234] [ka]

[0235] [ka]

[0236] [ka]

[0237] [ka]

[0238] <Organic anion> "M + X - In the compound represented by ", X - represents an organic anion. The organic anion is not particularly limited, and examples thereof include monovalent or divalent or higher organic anions. As the organic anion, an anion having a significantly low ability to cause a nucleophilic reaction is preferred, and a non-nucleophilic anion is more preferred.

[0239] 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.

[0240] 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).

[0241] 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.

[0242] The alkyl group, cycloalkyl group, and aryl group mentioned above may have a substituent. The substituent is not particularly limited, but specific examples thereof include a nitro group, a halogen atom such as a fluorine atom or a chlorine atom, a carboxy 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).

[0243] 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.

[0244] An example of the sulfonylimide anion is a saccharin anion.

[0245] 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 a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, an alkyloxysulfonyl group, an aryloxysulfonyl group, and a cycloalkylaryloxysulfonyl group, and a fluorine atom or an alkyl group substituted with a fluorine atom is 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.

[0246] Other non-nucleophilic anions include, for example, fluorinated phosphorus (e.g., PF6 - ), boron fluorides (e.g., BF4 - ), and antimony fluorides (e.g., SbF6 - ) are mentioned.

[0247] The non-nucleophilic anion is preferably an aliphatic sulfonate anion in which at least the α-position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, a bis(alkylsulfonyl)imide anion in which an alkyl group is substituted with a fluorine atom, or a tris(alkylsulfonyl)methide anion in which an alkyl group is substituted with a fluorine atom. Among these, a perfluoroaliphatic sulfonate anion (preferably having 4 to 8 carbon atoms) or a benzenesulfonate anion having a fluorine atom is more preferred, and a nonafluorobutanesulfonate anion, a perfluorooctane sulfonate anion, a pentafluorobenzenesulfonate anion, or a 3,5-bis(trifluoromethyl)benzenesulfonate anion is even more preferred.

[0248] A preferred example of the non-nucleophilic anion is an anion represented by the following formula (AN4).

[0249] [ka]

[0250] In formula (AN4), R 1 ~R 3 each independently represents an organic group or a hydrogen atom, and L represents a divalent linking group.

[0251] In formula (AN4), L represents a divalent linking group. When a plurality of L's are present, each L may be the same or different. Examples of the divalent linking group include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -S-, -SO-, -SO2-, alkylene groups (preferably having 1 to 6 carbon atoms), cycloalkylene groups (preferably having 3 to 15 carbon atoms), alkenylene groups (preferably having 2 to 6 carbon atoms), and divalent linking groups combining a plurality of these. Among these, the divalent linking group is preferably -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -SO2-, -O-CO-O-alkylene group-, -COO-alkylene group-, or -CONH-alkylene group-, and more preferably -O-CO-O-, -O-CO-O-alkylene group-, -COO-, -CONH-, -SO2-, or -COO-alkylene group-.

[0252] L is preferably, for example, a group represented by the following formula (AN4-2). * a -(CR 2a 2) X -Q-(CR 2b 2) Y -* b (AN4-2)

[0253] In formula (AN4-2), * a is R in formula (AN4) 3 represents the bonding position with * b is -C(R 1 )(R 2 )- represents the bonding position. X and Y each independently represent an integer of 0 to 10, and preferably an integer of 0 to 3. R 2a and R 2b each independently represents a hydrogen atom or a substituent. R 2a and R 2b If there are multiple instances of each, there are multiple instances of R 2a and R 2b may be the same or different. However, when Y is 1 or more, -C(R 1 )(R 2)- and CR 2b R in 2 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 -SO2-* B Represents. However, X+Y in formula (AN4-2) is 1 or more, and R in formula (AN4-2) 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 -SO2-* B Represents. * A is R in formula (AN4) 3 represents the bond position on the side, and * B is -SO3 in formula (AN4) - represents the bonding position on the side.

[0254] In formula (AN4), R 1 ~R 3 each independently represents an organic group. The organic group is not limited as long as it has one or more carbon atoms, and may be a linear group (e.g., a linear alkyl group), a branched group (e.g., a branched alkyl group such as a t-butyl group), or a cyclic group. The organic group may or may not have a substituent. The organic group may or may not have a heteroatom (e.g., an oxygen atom, a sulfur atom, and / or a nitrogen atom). Examples of the organic group also include substituents that are not electron-withdrawing groups. Examples of the substituent that is not an electron-withdrawing group include a hydrocarbon group, a hydroxyl group, an oxyhydrocarbon group, an oxycarbonyl hydrocarbon group, an amino group, a hydrocarbon-substituted amino group, and a hydrocarbon-substituted amide group. Furthermore, the substituents that are not electron-withdrawing groups are preferably each independently -R', -OH, -OR', -OCOR', -NH2, -NR'2, -NHR', or -NHCOR', where R' is a monovalent hydrocarbon group.

[0255] 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 monovalent aromatic hydrocarbon groups such as aralkyl groups such as benzyl, phenethyl, phenylpropyl, naphthylmethyl, and anthrylmethyl. Among them, R 1 and R 2 are each independently preferably a hydrocarbon group (preferably a cycloalkyl group) or a hydrogen atom.

[0256] Among them, R 3 is preferably an organic group having a cyclic structure. The cyclic structure may be monocyclic or polycyclic, and may have a substituent. The ring in the organic group having a cyclic structure is preferably directly bonded to L in formula (AN4). The organic group having a cyclic structure may or may not have a heteroatom (such as an oxygen atom, a sulfur atom, and / or a nitrogen atom), and the heteroatom may substitute 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, and 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, which may have a substituent. The cycloalkyl group may be monocyclic (such as a cyclohexyl group) or polycyclic (such as an adamantyl group), and preferably has 5 to 12 carbon atoms. As the lactone group and sultone group, for example, a group obtained by removing one hydrogen atom from a ring member atom constituting the lactone structure or sultone structure in any of the structures represented by the above formulae (LC1-1) to (LC1-21) and (SL1-1) to (SL1-3) is preferred.

[0257] The non-nucleophilic anion is also preferably an anion represented by the following formula (AN1).

[0258] [ka]

[0259] In formula (AN1), o represents an integer of 1 to 3. p represents an integer of 0 to 10. q represents an integer of 0 to 10.

[0260] Xf represents a fluorine atom or an organic group. The organic group may be an organic group substituted with at least one fluorine atom, or may be an organic group having no fluorine atoms. The number of carbon atoms in the organic group (preferably an alkyl group) is preferably 1 to 10, more preferably 1 to 4. Furthermore, the organic group (preferably an alkyl group) substituted with at least one fluorine atom is preferably a perfluoroalkyl group. At least one Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, more preferably a fluorine atom or CF3, and further preferably both Xf are fluorine atoms.

[0261] R4 and R5 each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom. When a plurality of R4s and R5s are present, they may be the same or different. The alkyl group represented by R4 and R5 preferably has 1 to 4 carbon atoms. The alkyl group may have a substituent. R4 and R5 are preferably hydrogen atoms. Specific examples and preferred embodiments of the alkyl group substituted with at least one fluorine atom are the same as the specific examples and preferred embodiments of Xf in formula (AN1).

[0262] L represents a divalent linking group. When a plurality of L's are present, each L may be the same or different. Examples of the divalent linking group include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -S-, -SO-, -SO2-, alkylene groups (preferably having 1 to 6 carbon atoms), cycloalkylene groups (preferably having 3 to 15 carbon atoms), alkenylene groups (preferably having 2 to 6 carbon atoms), and divalent linking groups combining a plurality of these. Among these, the divalent linking group is preferably -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -SO2-, -O-CO-O-alkylene group-, -COO-alkylene group-, or -CONH-alkylene group-, and more preferably -O-CO-O-, -O-CO-O-alkylene group-, -COO-, -CONH-, -SO2-, or -COO-alkylene group-.

[0263] W represents an organic group containing a cyclic structure, and is preferably a cyclic organic group. 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 monocyclic alicyclic groups include monocyclic cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of polycyclic alicyclic groups include polycyclic cycloalkyl groups 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.

[0264] The aryl group may be monocyclic or polycyclic, and 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, polycyclic heterocyclic groups can better suppress acid diffusion. 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.

[0265] The cyclic organic group may have a substituent. Examples of the substituent include an alkyl group (which may be linear or branched, and preferably has 1 to 12 carbon atoms), a cycloalkyl group (which may be 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 atoms constituting the cyclic organic group (carbon atoms contributing to ring formation) may be carbonyl carbons. Two or more substituents may be bonded to each other to form a ring. For example, two alkoxy groups, or a hydroxyl group and an alkoxy group may be bonded to each other to form a ring having a cyclic acetal structure. This ring may have a substituent. Examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms).

[0266] The anion represented by formula (AN1) is SO3 - -CF2-CH2-OCO-(L) q’ -W, SO3 - -CF2-CHF-CH2-OCO-(L) q’ -W, SO3 - -CF2-COO-(L) q’-W, SO3 - -CF2-CF2-CH2-CH2-(L) q -W or SO3 - -CF2-CH(CF3)-OCO-(L) q’ -W is preferred. Here, L, q and W are the same as those in formula (AN1). q' represents an integer of 0 to 10.

[0267] As the anion represented by formula (AN1), the following embodiments (AN2) and (AN3) are also preferred. Embodiment (AN2): In formula (AN1), o represents 2, p represents 0, and -SO3 - Two Xf bonded to the carbon atom directly bonded to (hereinafter, this carbon atom will also be referred to as "carbon atom Z1") each independently represent a hydrogen atom or an organic group having no fluorine atoms, and two Xf bonded to the carbon atom adjacent to the above carbon atom (hereinafter, this carbon atom will also be referred to as "carbon atom Z2") each independently represent a hydrogen atom or an organic group. Preferred aspects of q, L, and W are the same as those described above. The two Xf bonded to the carbon atom Z1 are preferably hydrogen atoms. At least one of the two Xf bonded to the carbon atom Z2 is preferably a fluorine atom or an organic group having a fluorine atom, more preferably both are fluorine atoms or organic groups having a fluorine atom, and further preferably both are alkyl groups substituted with fluorine.

[0268] Aspect (AN3): In formula (AN1), one of the two Xfs each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom, and the others each independently represent a hydrogen atom or an organic group having no fluorine atoms. Preferred aspects of o, p, q, R4, R5, L, and W are the same as those described above.

[0269] 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.

[0270] The non-nucleophilic anion is also preferably an aromatic sulfonate anion represented by the following formula (AN5).

[0271] [ka]

[0272] In formula (AN5), Ar represents an aryl group (e.g., a phenyl group) and may further have a substituent other than the sulfonate anion and the -(DB) group, such as a fluorine atom or a hydroxyl group.

[0273] n represents an integer of 0 or greater. n is preferably 1 to 4, more preferably 2 or 3, and even more preferably 3.

[0274] 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.

[0275] B represents a hydrocarbon group.

[0276] B is preferably an aliphatic hydrocarbon structure, and more preferably an isopropyl group, a cyclohexyl group, or an aryl group which may further have a substituent (such as a tricyclohexylphenyl group). Furthermore, B further states, "-(L) q -W”. L, q and W have the same meanings as L, q and W in the above formula (AN1), and specific examples and preferred ranges are also the same.

[0277] The non-nucleophilic anion is also preferably a disulfonamide anion. Disulfonamide anions are, for example, N - (SO2-R q )2 is an anion. where Rq 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.

[0278] Further, examples of the non-nucleophilic anion include anions represented by the following formulas (d1-1) to (d1-4).

[0279] [ka]

[0280] [ka]

[0281] 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).

[0282] 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). Z 2c The hydrocarbon group in the formula (I) may be linear or branched, or may have a cyclic structure. Furthermore, 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. Also, "Z" in formula (d1-2) 2c-SO3 - " is preferably different from the anion represented by the above formula (AN4), (AN1) or (AN5). For example, Z 2c is preferably other than an aryl group. 2c In -SO3 - 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 -SO3 - The atom at the α-position and / or the atom at the β-position to the is preferably a ring atom in a cyclic group.

[0283] 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.

[0284] In formula (d1-4), R 53 ~R 54 represents an organic group (preferably a hydrocarbon group having a fluorine atom). 53 ~R 54 may be bonded to each other to form a ring.

[0285] The organic anions may be used alone or in combination of two or more.

[0286] It is also preferable that the resist composition contains two or more types of compound (B), or that compound (B) is at least one type selected from the group consisting of the following compound (I) and the following compound (II).

[0287] <Compound (I) and Compound (II)> It is also preferable that the compound (B) is at least one selected from the group consisting of the following compound (I) and the following compound (II).

[0288] (Compound (I)) Compound (I) is a compound having one or more structural moieties X and one or more structural moieties Y, which, upon irradiation with actinic rays or radiation, generates an acid containing a first acidic moiety derived from the structural moiety X and a second acidic moiety derived from the structural moiety Y: Structural site X: Anion site A1 - and cationic moiety M1 + and a structural moiety that forms a first acidic moiety represented by HA1 upon irradiation with actinic rays or radiation. Structural site Y: Anionic site A2 - and cationic moiety M2 + and a structural portion that forms a second acidic site represented by HA2 upon irradiation with actinic rays or radiation. Cationic moiety M1 + and cationic moiety M2 + Each of M and M preferably independently represents an organic cation, and specific examples and preferred ranges are the same as those of M + It is the same as the organic cation represented by the formula: Furthermore, the compound (I) satisfies the following condition I.

[0289] Condition I: In the compound (I), the cation moiety M1 in the structural moiety X + and the cationic moiety M2 in the structural moiety Y. + H + The compound PI in which the cationic moiety M1 in the structural moiety X is replaced by + H + and the cationic moiety M2 in the structural moiety Y. + H + and an acid dissociation constant a2 derived from the acidic site represented by HA2 in which the acid dissociation constant a1 is replaced by the acid dissociation constant a2, which is greater than the acid dissociation constant a1.

[0290] 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 moieties derived from the structural moiety X and one of the second acidic moieties derived from the structural moiety Y, compound PI corresponds to a "compound having HA1 and HA2." More specifically, the acid dissociation constant a1 and the acid dissociation constant a2 of the compound PI are determined by determining whether the compound PI is "A1 - The pKa at which the compound is formed is the acid dissociation constant a1, and the above "A1 - and HA2" is "A1 - and A2 - The pKa at which the compound becomes "a compound having the above formula" is the acid dissociation constant a2.

[0291] Furthermore, when compound (I) is, for example, an acid-generating compound having two 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 corresponds to a "compound having two HA1s and one HA2." When the acid dissociation constant of such a compound PI is calculated, it is found that the compound PI is "one A1 - and one HA1 and one HA2,” and the acid dissociation constant when “one A1 - and one HA1 and one HA2" is "a compound with two A1 - The acid dissociation constant when "a compound having two A1 - and one HA2" is "a compound with two A1 - and A2 - In other words, in the case of such a compound PI, the acid dissociation constant when the compound becomes a compound having the cationic moiety M1 in the structural moiety X corresponds to the acid dissociation constant a2. + H + When the compound PI has a plurality of acid dissociation constants derived from the acidic moiety represented by HA1, the value of the acid dissociation constant a2 is greater than the largest value of the plurality of acid dissociation constants a1. -Let the acid dissociation constant when it becomes "a compound having one HA1 and one HA2" be aa, and "one A1" - Let the acid dissociation constant when the "compound having one A1, one HA1, and one HA2" becomes "a compound having two A1s" - and one HA2 be ab. When the relationship between aa and ab is considered, aa < ab is satisfied.

[0292] The acid dissociation constant a1 and the acid dissociation constant a2 are determined by the measurement method of the acid dissociation constant described above. The above compound PI corresponds to the acid generated when the compound (I) is irradiated with actinic rays or radiation. When the compound (I) has two or more structural sites X, the structural sites X may be the same or different from each other. Also, two or more of the above A1s - , and two or more of the above M1s + may be the same or different from each other. Also, in the compound (I), the above A1 - and the above A2 - , as well as the above M1 + and the above M2 + may be the same or different from each other, but the above A1 - and the above A2 - are preferably different from each other.

[0293] In the above compound PI, the difference (absolute value) between the acid dissociation constant a1 (when there are multiple acid dissociation constants a1, the maximum value thereof) and the acid dissociation constant a2 is preferably 0.1 or more, more preferably 0.5 or more, and still more preferably 1.0 or more. The upper limit value of the difference (absolute value) between the acid dissociation constant a1 (when there are multiple acid dissociation constants a1, the maximum value thereof) and the acid dissociation constant a2 is not particularly limited, but for example, it is 16 or less.

[0294] In the above compound PI, the acid dissociation constant a2 is, for example, 20 or less, and preferably 15 or less. As the lower limit value of the acid dissociation constant a2, -4.0 or more is preferable.

[0295] In the compound PI, the acid dissociation constant a1 is preferably not more than 2.0, more preferably not more than 0. The lower limit of the acid dissociation constant a1 is preferably not less than −20.0.

[0296] Anionic site A1 - and anionic site A2 - 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. Anionic site A1 - As the acid group, those capable of forming an acidic site 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. In addition, the anionic site A2 - As the anion moiety A1 - Preferably, it is one that can form an acidic site with a larger acid dissociation constant than the above, more preferably any one of formulas (BB-1) to (BB-6), and even more preferably any one of formulas (BB-1) and (BB-4). In the following formulae (AA-1) to (AA-3) and (BB-1) to (BB-6), * represents a bonding position. In formula (AA-2), R A each independently represents a monovalent organic group.

[0297] [ka]

[0298] [ka]

[0299] The specific structure of compound (I) is not particularly limited, and examples thereof include compounds represented by formulae (Ia-1) to (Ia-5) described below.

[0300] -Compound represented by formula (Ia-1)- First, the compound represented by formula (Ia-1) will be described below.

[0301] M 11 + A 11 - -L1-A 12 - M 12 + (Ia-1)

[0302] The compound represented by formula (Ia-1) can be irradiated with actinic rays or radiation to form HA. 11 -L1-A 12 It generates an acid represented by H.

[0303] In formula (Ia-1), M 11 + and M 12 + each independently represents an organic cation. A 11 - and A 12 - each independently represents a monovalent anionic functional group. L1 represents a divalent linking group. M 11 + and M 12 + may be the same or different. A 11 - and A 12 - may be the same or different, but are preferably different from each other. However, in the above formula (Ia-1), M 11 + and M 12 + The cation represented by H + Compound PIa (HA 11 -L1-A 12 In H), A 12 The acid dissociation constant a2 derived from the acidic site represented by H is HA 11The acid dissociation constant a1 is larger than the acid dissociation constant a1 derived from the acidic moiety represented by the formula (Ia-1). The preferred values ​​of the acid dissociation constant a1 and the acid dissociation constant a2 are as described above. The acid generated from the compound PIa and the compound represented by the formula (Ia-1) upon irradiation with actinic rays or radiation is the same. Also, M 11 + , M 12 + , A 11 - , A 12 - At least one of L1 and L2 may have an acid-decomposable group as a substituent.

[0304] In formula (Ia-1), M 11 + and M 12 + The organic cation represented by the formula + is the same as

[0305] A 11 - The monovalent anionic functional group represented by the formula (I) is the anionic moiety A1 - Also, A is intended to be a monovalent group containing 12 - The monovalent anionic functional group represented by the formula (I) is the anionic moiety A2 - is intended to mean a monovalent radical comprising: A 11 - and A 12 - The monovalent anionic functional group represented by the formula (AA-1) to (AA-3) and the formula (BB-1) to (BB-6) is preferably a monovalent anionic functional group containing an anionic moiety, and more preferably a monovalent anionic functional group selected from the group consisting of the formula (AX-1) to (AX-3) and the formula (BX-1) to (BX-7). 11 - Among them, the monovalent anionic functional group represented by formula (AX-1) to (AX-3) is preferable. 12 -Of the monovalent anionic functional groups represented by formula (BX-1), a monovalent anionic functional group represented by any one of formulas (BX-1) to (BX-7) is preferred, and a monovalent anionic functional group represented by any one of formulas (BX-1) to (BX-6) is more preferred.

[0306] [ka]

[0307] In formulas (AX-1) to (AX-3), R A1 and R A2 each independently represents a monovalent organic group. * represents a bonding position.

[0308] R A1 Examples of the monovalent organic group represented by the formula include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

[0309] R A2 The monovalent organic group represented by the formula (I) is preferably a linear, branched, or cyclic alkyl group or an aryl group. The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms. The alkyl group may have a substituent. The substituent is preferably a fluorine atom or a cyano group, more preferably a fluorine atom. When the alkyl group has a fluorine atom as a substituent, it may be a perfluoroalkyl group.

[0310] The aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may have a substituent. The substituent is preferably a fluorine atom, an iodine atom, a perfluoroalkyl group (for example, preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), or a cyano group, and more preferably a fluorine atom, an iodine atom, or a perfluoroalkyl group.

[0311] In formulas (BX-1) to (BX-4) and (BX-6), RB represents a monovalent organic group. * represents a bonding position. R B The monovalent organic group represented by the formula (I) is preferably a linear, branched, or cyclic alkyl group or an aryl group. The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms. The alkyl group may have a substituent. The substituent is not particularly limited, but is preferably a fluorine atom or a cyano group, more preferably a fluorine atom. When the alkyl group has a fluorine atom as a substituent, it may be a perfluoroalkyl group. In addition, the carbon atom that is the bonding position in the alkyl group (for example, in the case of formulas (BX-1) and (BX-4), the carbon atom that is directly bonded to -CO- specified in the formula in the alkyl group corresponds to this, in the case of formulas (BX-2) and (BX-3), the carbon atom that is directly bonded to -SO2- specified in the formula in the alkyl group corresponds to this, and in the case of formula (BX-6), the carbon atom that is directly bonded to -SO2- specified in the formula in the alkyl group corresponds to this - When ) has a substituent, the substituent is preferably a fluorine atom or a cyano group. In addition, the alkyl group may have a carbon atom substituted with a carbonyl carbon.

[0312] The aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may have a substituent. The substituent is preferably a fluorine atom, an iodine atom, a perfluoroalkyl group (for example, preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), a cyano group, an alkyl group (for example, preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), an alkoxy group (for example, preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), or an alkoxycarbonyl group (for example, preferably having 2 to 10 carbon atoms, more preferably having 2 to 6 carbon atoms), and more preferably a fluorine atom, an iodine atom, a perfluoroalkyl group, an alkyl group, an alkoxy group, or an alkoxycarbonyl group.

[0313] In formula (Ia-1), the divalent linking group represented by L1 is not particularly limited, and may be -CO-, -NR-, -CO-, -O-, -S-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms, which may be linear or branched), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), a divalent aliphatic heterocyclic group (having at least one N atom, O atom, S atom, or Se atom in the ring structure), or Examples of the R include a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, preferably a 5- to 7-membered ring, more preferably a 5- to 6-membered ring, divalent aromatic heterocyclic group (a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, preferably a 5- to 7-membered ring, more preferably a 5- to 6-membered ring), divalent aromatic hydrocarbon ring group (a 6- to 10-membered ring, more preferably a 6-membered ring), and a divalent linking group combining two or more of these. The R is, for example, a hydrogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but an alkyl group (preferably having 1 to 6 carbon atoms) is preferable. The alkylene group, the cycloalkylene group, the alkenylene group, the divalent aliphatic heterocyclic group, the divalent aromatic heterocyclic group, and the divalent aromatic hydrocarbon ring group may have a substituent, such as a halogen atom (preferably a fluorine atom).

[0314] Among these, the divalent linking group represented by L1 is preferably a divalent linking group represented by formula (L1).

[0315] [ka]

[0316] In formula (L1), L 111 represents a single bond or a divalent linking group. L 111The divalent linking group represented by the formula (I) is not particularly limited, and examples thereof include -CO-, -NH-, -O-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms, and more preferably having a straight chain or branched chain), an optionally substituted cycloalkylene group (preferably having 3 to 15 carbon atoms), an optionally substituted aryl group (preferably having 6 to 10 carbon atoms), and a divalent linking group formed by combining two or more of these. The substituent is not particularly limited, and examples thereof include a halogen atom. p represents an integer of 0 to 3, and preferably an integer of 1 to 3. v represents an integer of 0 or 1. Each Xf1 independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. Furthermore, the alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group. Each Xf2 independently represents a hydrogen atom, an alkyl group which may have a fluorine atom as a substituent, or a fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. Among these, Xf2 preferably represents a fluorine atom or an alkyl group substituted with at least one fluorine atom, and more preferably a fluorine atom or a perfluoroalkyl group. Among these, Xf1 and Xf2 are preferably each independently a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, and more preferably a fluorine atom or CF3. In particular, it is even more preferable that both Xf1 and Xf2 are fluorine atoms. * indicates the bond position. L in formula (Ia-1) 11 represents a divalent linking group represented by formula (L1), L in formula (L1) 111 The bond (*) on the side of the A 12 - It is preferred to combine with

[0317] -Compounds represented by formulae (Ia-2) to (Ia-4)- Next, the compounds represented by formulae (Ia-2) to (Ia-4) will be described.

[0318] [ka]

[0319] In formula (Ia-2), A 21a - and A 21b - Each independently represents a monovalent anionic functional group. 21a - and A 21b - The monovalent anionic functional group represented by the formula (I) is the anionic moiety A1 - A is intended to be a monovalent radical containing 21a - and A 21b - The monovalent anionic functional group represented by the formula (AX-1) is not particularly limited, and examples thereof include monovalent anionic functional groups selected from the group consisting of the above formulas (AX-1) to (AX-3). A 22 - represents a divalent anionic functional group. 22 - The divalent anionic functional group represented by the formula (I) is the anionic moiety A2 - A divalent group containing 22 - Examples of the divalent anionic functional group represented by the formula (BX-8) to (BX-11) shown below can be given.

[0320] [ka]

[0321] M 21a + , M 21b + , and M 22 + Each independently represents an organic cation.21a + , M 21b + , and M 22 + As the organic cation represented by the formula, the above-mentioned M1 + The same definition and preferred embodiments are also the same. L 21 and L 22 each independently represents a divalent organic group.

[0322] In addition, in the above formula (Ia-2), M 21a + , M 21b + , and M 22 + The organic cation represented by H + In compound PIa-2, A is replaced by 22 The acid dissociation constant a2 derived from the acidic site represented by H is A 21a Acid dissociation constants a1-1 and A1 derived from H 21b It is larger than the acid dissociation constant a1-2 derived from the acidic site represented by H. The acid dissociation constant a1-1 and the acid dissociation constant a1-2 correspond to the acid dissociation constant a1 described above. In addition, A 21a - and A 21b - may be the same or different. 21a + , M 21b + , and M 22 + may be the same or different from each other. Also, M 21a + , M 21b + , M 22 + , A 21a - , A 21b - , L 21 , and L 22 At least one of them may have an acid-decomposable group as a substituent.

[0323] In formula (Ia-3), A 31a - and A 32 - Each independently represents a monovalent anionic functional group. 31a - The definition of the monovalent anionic functional group represented by A in the above formula (Ia-2) is 21a - and A 21b - The same definition and preferred embodiments are also the same. A 32 - The monovalent anionic functional group represented by the above-mentioned anionic moiety A2 - A is intended to be a monovalent radical containing 32 - The monovalent anionic functional group represented by the formula (BX-1) is not particularly limited, and examples thereof include monovalent anionic functional groups selected from the group consisting of the above formulas (BX-1) to (BX-7). A 31b - represents a divalent anionic functional group. 31b - The divalent anionic functional group represented by the formula (I) is the anionic moiety A1 - A divalent group containing 31b - Examples of the divalent anionic functional group represented by formula (AX-4) include divalent anionic functional groups represented by formula (AX-4) shown below.

[0324] [ka]

[0325] M 31a + , M 31b + , and M 32 + Each independently represents a monovalent organic cation. 31a + , M 31b + , and M 32 +As the organic cation represented by the formula, the above-mentioned M1 + The same definition and preferred embodiments are also the same. L 31 and L 32 each independently represents a divalent organic group.

[0326] In addition, in the above formula (Ia-3), M 31a + , M 31b + , and M 32 + The organic cation represented by H + In compound PIa-3, A is replaced by 32 The acid dissociation constant a2 derived from the acidic site represented by H is A 31a Acid dissociation constants a1-3 and A2 derived from the acidic site represented by H 31b It is larger than the acid dissociation constant a1-4 derived from the acidic site represented by H. The acid dissociation constant a1-3 and the acid dissociation constant a1-4 correspond to the acid dissociation constant a1 described above. In addition, A 31a - and A 32 - may be the same or different. 31a + , M 31b + , and M 32 + may be the same or different from each other. Also, M 31a + , M 31b + , M 32 + , A 31a - , A 32 - , L 31 , and L 32 At least one of them may have an acid-decomposable group as a substituent.

[0327] In formula (Ia-4), A 41a - , A 41b - , and A42 - Each independently represents a monovalent anionic functional group. 41a - and A 41b - The definition of the monovalent anionic functional group represented by A in the above formula (Ia-2) is 21a - and A 21b - Also, A 42 - The definition of the monovalent anionic functional group represented by A in the above formula (Ia-3) is 32 - The same definition and preferred embodiments are also the same. M 41a + , M 41b + , and M 42 + each independently represents an organic cation. L 41 represents a trivalent organic group.

[0328] In addition, in the above formula (Ia-4), M 41a + , M 41b + , and M 42 + The organic cation represented by H + In compound PIa-4, A is replaced by 42 The acid dissociation constant a2 derived from the acidic site represented by H is A 41a Acid dissociation constants a1-5 and A2 derived from the acidic site represented by H 41b It is larger than the acid dissociation constant a1-6 derived from the acidic site represented by H. The acid dissociation constant a1-5 and the acid dissociation constant a1-6 correspond to the acid dissociation constant a1 described above. In addition, A 41a - , A 41b - , and A 42 - may be the same or different. 41a + , M 41b+ , and M 42 + may be the same or different from each other. Also, M 41a + , M 41b + , M 42 + , A 41a - , A 41b - , A 42 - , and L 41 At least one of them may have an acid-decomposable group as a substituent.

[0329] L in formula (Ia-2) 21 and L 22 and L in formula (Ia-3). 31 and L 32 The divalent organic group represented by the formula (I) is not particularly limited, and examples thereof include -CO-, -NR-, -O-, -S-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms, which may be linear or branched), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), a divalent aliphatic heterocyclic group (preferably a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, more preferably a 5- to 7-membered ring, and even more preferably a 5- to 6-membered ring), a divalent aromatic heterocyclic group (preferably a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, more preferably a 5- to 7-membered ring, and even more preferably a 5- to 6-membered ring), a divalent aromatic hydrocarbon ring group (preferably a 6- to 10-membered ring, and even more preferably a 6-membered ring), and a divalent organic group formed by combining two or more of these. The above R may be a hydrogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but is preferably, for example, an alkyl group (preferably having 1 to 6 carbon atoms). The alkylene group, the cycloalkylene group, the alkenylene group, the divalent aliphatic heterocyclic group, the divalent aromatic heterocyclic group, and the divalent aromatic hydrocarbon ring group may have a substituent, such as a halogen atom (preferably a fluorine atom).

[0330] L in formula (Ia-2) 21 and L 22 and L in formula (Ia-3). 31 and L 32 The divalent organic group represented by the formula (L1) is preferably, for example, a divalent organic group represented by the following formula (L2).

[0331] [ka]

[0332] In formula (L2), q represents an integer of 1 to 3. * represents a bonding position. Each Xf independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. Furthermore, 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, more preferably a fluorine atom or CF3, and particularly preferably both Xf are fluorine atoms.

[0333] L A represents a single bond or a divalent linking group. L A The divalent linking group represented by the formula (I) is not particularly limited, and examples thereof include -CO-, -O-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms, which may be linear or branched), a cycloalkylene group (preferably having 3 to 15 carbon atoms), a divalent aromatic hydrocarbon ring group (preferably a 6- to 10-membered ring, more preferably a 6-membered ring), and a divalent linking group formed by combining two or more of these. The alkylene group, the cycloalkylene group, and the divalent aromatic hydrocarbon ring group may have a substituent, such as a halogen atom (preferably a fluorine atom).

[0334] Examples of the divalent organic group represented by formula (L2) include *-CF2-*, *-CF2-CF2-*, *-CF2-CF2-CF2-*, *-Ph-O-SO2-CF2-*, *-Ph-O-SO2-CF2-CF2-*, *-Ph-O-SO2-CF2-CF2-CF2-*, and *-Ph-OCO-CF2-*. Ph represents a phenylene group which may have a substituent, and is preferably a 1,4-phenylene group. The substituent is not particularly limited, but is preferably an alkyl group (e.g., preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), an alkoxy group (e.g., preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), or an alkoxycarbonyl group (e.g., preferably having 2 to 10 carbon atoms, more preferably having 2 to 6 carbon atoms). L in formula (Ia-2) 21 and L 22 represents a divalent organic group represented by formula (L2), L in formula (L2) A The bond (*) on the side of the A 21a - and A 21b - It is preferred to combine with Furthermore, L in formula (Ia-3) 31 and L 32 represents a divalent organic group represented by formula (L2), L in formula (L2) A The bond (*) on the side of the A 31a - and A 32 - It is preferred to combine with

[0335] -Compound represented by formula (Ia-5)- Next, formula (Ia-5) will be described.

[0336] [ka]

[0337] In formula (Ia-5), A 51a - , A 51b -, and A 51c - Each independently represents a monovalent anionic functional group. 51a - , A 51b - , and A 51c - The monovalent anionic functional group represented by the formula (I) is the anionic moiety A1 - A is intended to be a monovalent radical containing 51a - , A 51b - , and A 51c - The monovalent anionic functional group represented by the formula (AX-1) is not particularly limited, and examples thereof include monovalent anionic functional groups selected from the group consisting of the above formulas (AX-1) to (AX-3). A 52a - and A 52b - represents a divalent anionic functional group. 52a - and A 52b - The divalent anionic functional group represented by the formula (I) is the anionic moiety A2 - A divalent group containing 52a - and A 52b - Examples of the divalent anionic functional group represented by the formula (BX-8) to (BX-11) include divalent anionic functional groups selected from the group consisting of the above formulas (BX-8) to (BX-11).

[0338] M 51a + , M 51b + , M 51c + , M 52a + , and M 52b + Each independently represents an organic cation. 51a + , M 51b + , M 51c + , M 52a+ , and M 52b + As the organic cation represented by the formula, the above-mentioned M1 + The same definition and preferred embodiments are also the same. L 51 and L 53 L each independently represents a divalent organic group. 51 and L 53 Examples of the divalent organic group represented by the formula (Ia-2) include L 21 and L 22 The same definition and preferred embodiments are also the same. L 52 represents a trivalent organic group. 52 The trivalent organic group represented by the formula (Ia-4) is L 41 The same definition and preferred embodiments are also the same.

[0339] In addition, in the above formula (Ia-5), M 51a + , M 51b + , M 51c + , M 52a + , and M 52b + The organic cation represented by H + In compound PIa-5, A is replaced by 52a The acid dissociation constants a2-1 and A2-1 derived from the acidic site represented by H 52b The acid dissociation constant a2-2 derived from the acidic site represented by H is A 51a Acid dissociation constant a1-1, A 51b The acid dissociation constants a1-2 and A2 are derived from the acidic sites represented by H. 51c It is larger than the acid dissociation constant a1-3 derived from the acidic site represented by H. The acid dissociation constants a1-1 to a1-3 correspond to the above-mentioned acid dissociation constant a1, and the acid dissociation constants a2-1 and a2-2 correspond to the above-mentioned acid dissociation constant a2. In addition, A 51a - , A 51b - , and A 51c -may be the same or different. 52a - and A 52b - may be the same or different. 51a + , M 51b + , M 51c + , M 52a + , and M 52b + may be the same or different from each other. Also, M 51b + , M 51c + , M 52a + , M 52b + , A 51a - , A 51b - , A 51c - , L 51 , L 52 , and L 53 At least one of them may have an acid-decomposable group as a substituent.

[0340] (Compound (II)) Compound (II) is a compound having two or more of the structural moieties X described above and one or more of the structural moieties Z described below, and is a compound that generates an acid containing two or more of the first acidic moieties derived from the structural moiety X and the structural moiety Z when irradiated with actinic rays or radiation. Structural site Z: a ​​non-ionic site capable of neutralizing acids

[0341] In compound (II), the definition of the structural moiety X and A1 - and M1 + The definition of the structural moiety X in the compound (I) and A1 - and M1 + The definition and preferred embodiments are also the same.

[0342] In the compound (II), the cation moiety M1 in the structural moiety X + H + In the compound PII, the cationic moiety M1 in the structural moiety X is replaced by + H + The preferred range of the acid dissociation constant a1 derived from the acidic moiety represented by HA1 in which the acid dissociation constant a1 is substituted with HA1 is the same as the acid dissociation constant a1 in the compound PI. In addition, when compound (II) is, for example, a compound that generates an acid having two of the first acidic sites derived from the structural site X and the structural site Z, compound PII corresponds to a "compound having two HA1s." When the acid dissociation constant of this compound PII is calculated, it is considered that compound PII has "one A1 - and one HA1" and the acid dissociation constant when "a compound having one A1" - and one HA1" is "a compound with two A1 - The acid dissociation constant when the compound becomes "a compound having the formula (I)" corresponds to the acid dissociation constant a1.

[0343] The acid dissociation constant a1 can be determined by the above-mentioned method for measuring an acid dissociation constant. The compound PII corresponds to an 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. - , and two or more of the above M1 + may be the same or different.

[0344] 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 an electron. Examples of the group capable of electrostatically interacting with a proton or the functional group having an electron include a functional group having a macrocyclic structure such as a cyclic polyether, or a functional group 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:

[0345] [ka]

[0346] 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 to tertiary amine structure, a pyridine structure, an imidazole structure, and a pyrazine structure, and among these, a primary to tertiary amine structure is preferred.

[0347] Compound (II) is not particularly limited, but examples thereof include compounds represented by the following formula (IIa-1) and formula (IIa-2).

[0348] [ka]

[0349] In the above formula (IIa-1), A 61a - and A 61b - are A in the above formula (Ia-1), respectively. 11 - The same definition and preferred embodiments are also the same. 61a + and M 61b + are the M in the above formula (Ia-1), 11 + The same definition and preferred embodiments are also the same. In the above formula (IIa-1), L 61 and L 62 have the same meanings as L1 in the above formula (Ia-1), and the preferred embodiments are also the same.

[0350] In formula (IIa-1), R 2X represents a monovalent organic group. 2X The monovalent organic group represented by the formula (I) is not particularly limited, and examples thereof include an alkyl group (preferably having 1 to 10 carbon atoms, which may be linear or branched), a cycloalkyl group (preferably having 3 to 15 carbon atoms), or an alkenyl group (preferably having 2 to 6 carbon atoms), in which -CH2- may be substituted with one or a combination of two or more selected from the group consisting of -CO-, -NH-, -O-, -S-, -SO-, and -SO2-. The alkylene group, cycloalkylene group, and alkenylene group may have a substituent. The substituent is not particularly limited, but examples thereof include a halogen atom (preferably a fluorine atom).

[0351] In addition, in the above formula (IIa-1), M 61a + and M 61b + The organic cation represented by H + In the compound PIIa-1, A is replaced by 61a Acid dissociation constants a1-7 and A2 derived from the acidic site represented by H 61b The acid dissociation constant a1-8 derived from the acidic site represented by H corresponds to the above-mentioned acid dissociation constant a1. In the compound (IIa-1), the cationic moiety M in the structural moiety X 61a + and M 61b + H + Compound PIIa-1, which is substituted with HA 61a -L 61 -N(R 2X )-L 62 -A 61b The compound PIIa-1 corresponds to H. The acid generated from the compound represented by formula (IIa-1) upon irradiation with actinic rays or radiation is the same as that generated from the compound PIIa-1. Also, M 61a + , M 61b + , A61a - , A 61b - , L 61 , L 62 , and R 2X At least one of them may have an acid-decomposable group as a substituent.

[0352] In the above formula (IIa-2), A 71a - , A 71b - , and A 71c - are A in the above formula (Ia-1), respectively. 11 - The same definition and preferred embodiments are also the same. 71a + , M 71b + , and M 71c + are the M in the above formula (Ia-1), 11 + The same definition and preferred embodiments are also the same. In the above formula (IIa-2), L 71 , L 72 , and L 73 have the same meanings as L1 in the above formula (Ia-1), and the preferred embodiments are also the same.

[0353] In addition, in the above formula (IIa-2), M 71a + , M 71b + , and M 71c + The organic cation represented by H + In the compound PIIa-2, A is replaced by 71a Acid dissociation constant a1-9, A, derived from the acidic site represented by H 71b The acid dissociation constant a1-10 derived from the acidic site represented by H, and A 71c The acid dissociation constant a1-11 derived from the acidic site represented by H corresponds to the acid dissociation constant a1 described above. In the compound (IIa-1), the cationic moiety M in the structural moiety X 71a +, M 71b + , and M 71c + H + Compound PIIa-2, which is substituted with HA 71a -L 71 -N(L 73 -A 71c H)-L 72 -A 71b The compound PIIa-2 corresponds to H. The acid generated from the compound represented by formula (IIa-2) upon irradiation with actinic rays or radiation is the same as that generated from the compound PIIa-2. Also, M 71a + , M 71b + , M 71c + , A 71a - , A 71b - , A 71c - , L 71 , L 72 , and L 73 At least one of them may have an acid-decomposable group as a substituent.

[0354] Examples of anionic moieties that Compound (I) and Compound (II) may have are shown below, but the present invention is not limited to these.

[0355] [ka]

[0356] [ka]

[0357] As the compound (B), it is also preferable to use the photoacid generators disclosed in, for example, paragraphs

[0135] to

[0171] of WO 2018 / 193954, paragraphs

[0077] to

[0116] of WO 2020 / 066824, and paragraphs

[0018] to

[0075] and

[0334] to

[0335] of WO 2017 / 154345.

[0358] The content of compound (B) in the resist composition is not particularly limited, but in order to form a more rectangular cross-sectional pattern, it is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total solid content of the resist composition. Furthermore, the content of compound (B) is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, based on the total solid content of the resist composition. The compound (B) may be used alone or in combination of two or more.

[0359] The compound (B) may also be the following compound (X).

[0360] <Compound (X)> The compound (X) is a salt containing a cation (specific cation) represented by the following formula (X).

[0361] [ka]

[0362] In formula (X), Ar X represents an aryl group substituted with a group containing a halogen atom. Ar x The aryl group represented by the formula (I) may be monocyclic or polycyclic. The aryl group may also be a heterocyclic group containing an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the hetero ring include a pyrrole ring, a furan ring, a thiophene ring, an indole ring, a benzofuran ring, and a benzothiophene ring. The number of carbon atoms in the aryl group (Ar X The number of carbon atoms in the alkyl group is preferably 6 to 20, more preferably 6 to 15, and even more preferably 6 to 10.

[0363] The group containing a halogen atom means a halogen atom itself and a group containing a halogen atom as part of a substituent. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine and iodine atoms being preferred. Examples of groups containing a halogen atom include a halogen atom, a halogenated alkyl group, a halogenated alkoxy group, and a halogenated aryl group. The number of halogen atoms contained in the aryl group is preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 10. The number of halogen atom-containing groups contained in the aryl group is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3. The aryl group may be substituted with a group not containing a halogen atom in addition to the group containing a halogen atom. The group not containing a halogen atom is preferably an alkyl group (preferably having 1 to 6 carbon atoms), an alkoxy group, or an alkoxycarbonyl group, more preferably an alkyl group (preferably having 1 to 6 carbon atoms) or an alkoxy group (preferably having 1 to 6 carbon atoms). The aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group.

[0364] R X11 ~R X16 each independently represents a hydrogen atom or a hydrocarbon group. R X11 ~R X12 At least one of R is preferably a hydrocarbon group. X13 ~R X16 preferably represents a hydrogen atom. The hydrocarbon group may be linear, branched, or cyclic. Examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an alkenyl group, and an aryl group, with an alkyl group being preferred. The hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms. R X11 and R X12 may be bonded to each other to form a ring, and R X11 and R X13~R X16 and at least one of, or R X12 and R X13 ~R X16 may be bonded to each other to form a ring.

[0365] n and m each independently represent an integer of 1 or more. n and m are preferably 1 to 10, more preferably 1 to 5, still more preferably 1 to 3, and particularly preferably 2. Furthermore, n and m preferably represent the same integer. When n is an integer of 2 or more, two or more R X13 R and two or more X14 When m is an integer of 2 or more, two or more R X15 R and two or more X16 They may be the same or different.

[0366] L X represents a divalent linking group. Examples of the divalent linking group include -CO- and -NR A -, -O-, -S-, -SO-, -SO2-, -N(SO2-R A )-, an alkylene group, a cycloalkylene group, an alkenylene group, and a divalent linking group formed by combining a plurality of these groups, and a divalent linking group containing an oxygen atom is preferred. Examples of the divalent linking group containing an oxygen atom include -CO-, -O-, -SO-, -SO2-, and -N(SO2-R A )-, and divalent linking groups formed by combining a plurality of these. A Examples of the alkyl group include a hydrogen atom and an alkyl group having 1 to 6 carbon atoms. Among them, the divalent linking group containing an oxygen atom is -O-, -CO-, or -N(SO2-R A )- is preferred, and -O- or -CO- is more preferred. The divalent linking group containing an oxygen atom means an oxygen atom itself, and a divalent linking group containing an oxygen atom as part of the divalent linking group. The number of oxygen atoms contained in the divalent linking group containing an oxygen atom is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1.

[0367] The specific cation is preferably a cation represented by formula (X-1).

[0368] [ka]

[0369] In formula (X-1), X1 represents a group containing a halogen atom. X1 is Ar in the above formula (X). x The meaning and preferred range of the halogen atom-containing group are the same as those of the halogen atom-containing group.

[0370] Y1 represents a group containing no halogen atoms. The group not containing a halogen atom is preferably an alkyl group (preferably having 1 to 6 carbon atoms), an alkoxy group, or an alkoxycarbonyl group, more preferably an alkyl group (preferably having 1 to 6 carbon atoms) or an alkoxy group. The group not containing a halogen atom means a group not containing a halogen atom as a part of a substituent, that is, Y1 represents a group other than the group containing a halogen atom represented by X1.

[0371] a represents an integer of 1 to 5, b represents an integer of 0 to 4, and a+b is 1 to 5. a is preferably 1 to 4. b is preferably 1 to 4.

[0372] R X20 ~R X29 each independently represents a hydrogen atom or a hydrocarbon group. R X20 ~R X21 is R in the above formula (X). X11 ~R X12 The same definition and preferred range are also the same. R X22 ~R X29The hydrocarbon group represented by may be linear, branched, or cyclic. R X22 ~R X29 Examples of the hydrocarbon group represented by the formula (I) include an alkyl group, a cycloalkyl group, an alkenyl group, and an aryl group, and an alkyl group is preferred. R X22 ~R X29 The hydrocarbon group represented by the formula (I) preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms. R X20 and R X21 may be bonded to each other to form a ring, and R 20 and R X22 ~R X25 and at least one of, or R X21 and R X26 ~R X29 may be bonded to each other to form a ring.

[0373] The specific cations may be used alone or in combination of two or more.

[0374] The molecular weight of the compound (X) is preferably 100 to 10,000, more preferably 100 to 2,500, and even more preferably 100 to 1,500.

[0375] The preferred range of the content of the compound (X) is the same as the preferred range of the content of the compound (B) described above. The compound (X) may be used alone or in combination of two or more. When two or more compounds are used, the total content thereof is preferably within the above-mentioned preferred content range.

[0376] Specific examples of compound (X) are shown below, but the present invention is not limited to these.

[0377] [ka]

[0378] [ka]

[0379] [Acid diffusion controller] The resist composition may contain an acid diffusion controller. The acid diffusion controller acts as a quencher that traps the acid generated from the photoacid generator or the like during exposure and inhibits the reaction of the acid-decomposable resin in the unexposed areas caused by excess acid generated. Examples of acid diffusion controllers include basic compounds (CA), low molecular weight compounds (CB) having a nitrogen atom and a group that is cleaved by the action of an acid, and compounds (CC) whose acid diffusion control ability is reduced or lost upon irradiation with actinic rays or radiation. Examples of the compound (CC) include an onium salt compound (CD) that is a weak acid relative to the photoacid generator, and a basic compound (CE) that loses or loses basicity upon irradiation with actinic rays or radiation. As the acid diffusion controller, known acid diffusion controllers can be used appropriately. For example, known compounds disclosed in U.S. Patent Application Publication No. 2016 / 0070167A1, paragraphs

[0627] to

[0664] , U.S. Patent Application Publication No. 2015 / 0004544A1, paragraphs

[0095] to

[0187] , U.S. Patent Application Publication No. 2016 / 0237190A1, paragraphs

[0403] to

[0423] , and U.S. Patent Application Publication No. 2016 / 0274458A1, paragraphs

[0259] to

[0328] can be suitably used as the acid diffusion controller. Further, for example, specific examples of basic compounds (CA) include those described in paragraphs

[0132] to

[0136] of WO 2020 / 066824, specific examples of basic compounds (CD) 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, specific examples of low molecular weight compounds (CB) having a nitrogen atom and a group that is released by the action of an acid include those described in paragraphs

[0156] to

[0163] of WO 2020 / 066824, and specific examples of onium salt compounds (CE) having a nitrogen atom in the cation moiety include those described in paragraph

[0164] of WO 2020 / 066824. Specific examples of onium salt compounds (CDs) that are relatively weakly acidic compared to photoacid generators include those described in paragraphs

[0305] to

[0314] of WO 2020 / 158337, paragraphs

[0455] to

[0464] of WO 2020 / 158467, paragraphs

[0298] to

[0307] of WO 2020 / 158366, and paragraphs

[0357] to

[0366] of WO 2020 / 158417.

[0380] When the resist composition contains an acid diffusion controller, the content of the acid diffusion controller (the total content if multiple types are present) is preferably 0.1 to 15.0 mass %, and more preferably 1.0 to 15.0 mass %, relative to the total solid content of the composition. In the resist composition, the acid diffusion controller may be used alone or in combination of two or more types.

[0381] [Hydrophobic resin (D)] The resist composition may further contain a hydrophobic resin that is different from the resin (A). The hydrophobic resin is preferably designed to be 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 polar and non-polar substances. The effects of adding a hydrophobic resin include control of the static and dynamic contact angle of water on the surface of the resist film and suppression of outgassing.

[0382] From the viewpoint of uneven distribution in the film surface layer, the hydrophobic resin preferably has one or more of a fluorine atom, a silicon atom, and a CH3 partial structure contained in a side chain portion of the resin, and more preferably has two or more of these. Furthermore, the hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be contained in the main chain of the resin or may be substituted on the side chain. Examples of hydrophobic resins include the compounds described in paragraphs

[0275] to

[0279] of WO 2020 / 004306.

[0383] When the resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably from 0.01 to 20.0 mass %, and more preferably from 0.1 to 15.0 mass %, relative to the total solid content of the resist composition.

[0384] [Surfactant (E)] The resist composition may contain a surfactant, which can provide superior adhesion and allow the formation of a pattern with fewer development defects. The surfactant is preferably a fluorine-based and / or silicon-based surfactant. Examples of fluorine-based and / or silicone-based surfactants include surfactants disclosed in paragraphs

[0218] and

[0219] of WO 2018 / 19395.

[0385] These surfactants may be used alone or in combination of two or more.

[0386] When the resist composition contains a surfactant, the content of the surfactant is preferably from 0.0001 to 2.0 mass %, more preferably from 0.0005 to 1.0 mass %, and even more preferably from 0.1 to 1.0 mass %, relative to the total solid content of the composition.

[0387] [Other additives] The resist composition may further contain a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and / or a compound that promotes solubility in a developer (for example, a phenol compound having a molecular weight of 1000 or less, or an alicyclic or aliphatic compound containing a carboxy group).

[0388] The resist composition may further contain a dissolution inhibiting compound. Here, the term "dissolution inhibiting compound" refers to a compound with a molecular weight of 3000 or less that decomposes under the action of acid and reduces its solubility in an organic developer.

[0389] The resist composition of the present invention is suitably used as an EUV light-sensitive composition. EUV light has a wavelength of 13.5 nm, which is shorter than ArF light (wavelength 193 nm), and therefore the number of incident photons is smaller when exposed at the same sensitivity. As a result, the effect of "photon shot noise," which is the stochastic variation in the number of photons, is significant, leading to deterioration of LER and bridge defects. One way to reduce photon shot noise is to increase the exposure dose and the number of incident photons, but this comes at a trade-off with the demand for higher sensitivity.

[0390] When the value A calculated by the following formula (1) is high, the resist film formed from the resist composition will have a high absorption efficiency of EUV light and electron beams, which is effective in reducing photon shot noise. The value A represents the absorption efficiency of EUV light and electron beams by mass of the resist film. Formula (1): A=([H]×0.04+[C]×1.0+[N]×2.1+[O]×3.6+[F]×5.6+[S]×1.5+[I]×39.5) / ([H]×1+[C]×12+[N]×14+[O]×16+[F]×19+[S]×32+[I]×127) The value A is preferably 0.120 or more. Although there is no particular upper limit, if the value A is too large, the EUV light and electron beam transmittance of the resist film decreases, deteriorating the optical image profile in the resist film and making it difficult to obtain a good pattern shape. Therefore, the value A is preferably 0.240 or less, and more preferably 0.220 or less.

[0391] In formula (1), [H] represents the molar ratio of hydrogen atoms derived from all solids to all atoms in all solids in the actinic ray-sensitive or radiation-sensitive resin composition, [C] represents the molar ratio of carbon atoms derived from all solids to all atoms in all solids in the actinic ray-sensitive or radiation-sensitive resin composition, [N] represents the molar ratio of nitrogen atoms derived from all solids to all atoms in all solids in the actinic ray-sensitive or radiation-sensitive resin composition, and [O] represents the molar ratio of 0 to 10 atoms in the actinic ray-sensitive or radiation-sensitive resin composition. [F] represents the molar ratio of oxygen atoms derived from all solids to all atoms in all solids, [F] represents the molar ratio of fluorine atoms derived from all solids to all atoms in all solids in the actinic ray-sensitive or radiation-sensitive resin composition, [S] represents the molar ratio of sulfur atoms derived from all solids to all atoms in all solids in the actinic ray-sensitive or radiation-sensitive resin composition, and [I] represents the molar ratio of iodine atoms derived from all solids to all atoms in all solids in the actinic ray-sensitive or radiation-sensitive resin composition. For example, when a resist composition contains a resin whose polarity increases under the action of acid (acid-decomposable resin), a photoacid generator, an acid diffusion controller, and a solvent, the resin, the photoacid generator, and the acid diffusion controller correspond to the solid content. In other words, the total atoms of the total solid content correspond to the sum of all atoms derived from the resin, all atoms derived from the photoacid generator, and all atoms derived from the acid diffusion controller. For example, [H] represents the molar ratio of hydrogen atoms derived from all solid content to all atoms of the total solid content. Based on the above example, [H] represents the molar ratio of the sum of hydrogen atoms derived from the resin, the photoacid generator, and the acid diffusion controller to the sum of all atoms derived from the resin, the photoacid generator, and the acid diffusion controller.

[0392] The A value can be calculated by calculating the atomic ratio of the components contained in the resist composition when the structure and content of all solid components in the resist composition are known. Even when the components are unknown, the atomic ratio of the components can be calculated by analytical techniques such as elemental analysis of the resist film obtained by evaporating the solvent component of the resist composition.

[0393] [Electronic device manufacturing method] The present invention also relates to a method for manufacturing an electronic device, which includes the above-described pattern formation method, and an electronic device manufactured by this manufacturing method. A preferred embodiment of the electronic device of the present invention is one in which it is installed in electrical and electronic equipment (such as home appliances, OA (Office Automation), media-related equipment, optical equipment, and communication equipment). [Example]

[0394] 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.

[0395] [Various components of resist composition] 〔resin〕 Resins Pol-1 to Pol-32 were synthesized according to known methods. Tables 1 and 2 show the ratio (content (mol%)) of each repeating unit, weight average molecular weight (Mw), and dispersity (Mw / Mn). The weight average molecular weight (Mw) and dispersity (Mw / Mn) of resins Pol-01 to Pol-32 were measured by GPC (carrier: tetrahydrofuran (THF)) (amounts calculated as polystyrene). 13 Measurement was performed by C-NMR (nuclear magnetic resonance).

[0396] [Table 1]

[0397] [Table 2]

[0398] The structural formulas of the repeating units shown in Tables 1 and 2 are shown below.

[0399] [ka]

[0400] [ka]

[0401] [Photoacid generator] The structures of the photoacid generators (PAG-1 to PAG-27) used are shown below.

[0402] [ka]

[0403] [ka]

[0404] [ka]

[0405] [ka]

[0406] Tables 3 and 4 below show the molecular weights of the acids generated by the photoacid generators.

[0407] [Table 3]

[0408] [Table 4]

[0409] [Acid diffusion controller and other additives] The structures of the acid diffusion controllers (PQ-01 to PQ-08, Q-01 to Q-04) and the other additive (CL-1) used are shown below. E-3 is PF656 (a fluorosurfactant manufactured by OMNOVA).

[0410] [ka]

[0411] [ka]

[0412] [Hydrophobic resin] Hydrophobic resins D-1 to D-3 were synthesized according to known methods. Table 5 shows the ratio (content (mol%)) of each repeating unit, weight average molecular weight (Mw), and dispersity (Mw / Mn). The weight average molecular weight (Mw) and dispersity (Mw / Mn) of hydrophobic resins D-1 to D-3 were measured by GPC (carrier: tetrahydrofuran (THF)) (amounts converted into polystyrene). The composition ratio (molar ratio) of the resins was 13 Measurement was performed by C-NMR (nuclear magnetic resonance).

[0413] [Table 5]

[0414] The structural formulas of the repeating units shown in Table 5 are shown below.

[0415] [ka]

[0416] 〔solvent〕 The solvents used are shown below. 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

[0417] [Preparation of Resist Composition] Resist compositions (Res-01 to Res-52) were prepared by dissolving the components shown in Tables 6, 7, and 8 in the solvents shown in Tables 6, 7, and 8, and filtering the resulting solution through a polyethylene filter with a pore size of 0.03 μm. The content (parts by mass) of each component and solvent in the resist compositions is shown in Tables 6, 7, and 8.

[0418] [Table 6]

[0419] [Table 7]

[0420] [Table 8]

[0421] [Preparation of organic processing solution] Organic processing solutions (R-01 to R-19) were prepared by mixing the organic solvents shown in Table 9 below to obtain the contents shown in Table 9. The obtained organic processing solutions were used as the developing solutions or rinsing solutions described below.

[0422] [Table 9]

[0423] [Formation of Resist Film, Pattern Formation and Development] An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a film with a thickness of 5 nm. Each resist composition prepared as shown in Tables 10 and 11 was applied thereon and baked (PB) for 60 seconds at the temperature shown in Tables 10 and 11 to form a resist film with a thickness of 40 nm. Using an EUV exposure system (Exitech, Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36), the entire surface of the silicon wafer bearing the resulting resist film was subjected to pattern irradiation at the same exposure dose. A mask with a line size of 20 nm and a line:space ratio of 1:1 was used as the reticle. After irradiation, the wafer was baked (PEB) for 60 seconds on a hot plate at the temperature listed in Tables 10 and 11. The wafer was then puddled with a developer listed in Tables 10 and 11 for 30 seconds, and the rinse solution listed in Tables 10 and 11 was poured onto the wafer. The wafer was then rotated and baked at 100°C for 60 seconds, yielding a 1:1 line-and-space pattern with a line width of 20 nm.

[0424] [Evaluation of in-plane line width uniformity] The line widths of the obtained line-and-space patterns were measured using a critical dimension scanning electron microscope (SEM, Hitachi S-9380II). The standard deviation (σ) of the measured line widths was tripled (3σ), which was calculated as an index of the in-plane uniformity of the line widths. Specifically, exposure was performed on the wafer with 8 columns in the x direction and 29 rows in the y direction, for a total of 232 shots, with 3.5 mm vertically (y-axis direction) and 6.5 mm horizontally (x-axis direction) as one shot. Ten critical dimension photographs (5 lines per photograph) were measured for each shot, and the average of the 10 measurement values ​​was used as the critical dimension for that shot. The standard deviation of the measurement values ​​for the 232 shots was tripled to obtain 3σ. The results are shown in Tables 10 and 11. The unit of in-plane line width uniformity in Tables 10 and 11 below is "nm."

[0425] [Table 10]

[0426] [Table 11]

[0427] The evaluation results in Tables 10 and 11 show that the pattern forming methods of the examples provide excellent in-plane uniformity of the line width of the patterns obtained. Both Example 5 and Comparative Example 1 were developed using the organic treatment liquid R-05, but Example 5 had better in-plane line width uniformity than Comparative Example 1. This is thought to be because Comparative Example 1 used a negative-tone chemically amplified resist composition (Res-46) that becomes negative through a crosslinking reaction, and therefore the organic treatment liquid R-05 did not wet and spread uniformly over the resist film. In both Example 27 and Comparative Examples 2 to 5, development was performed using organic treatment liquid R-12, but Example 27 exhibited better in-plane line width uniformity than Comparative Examples 2 to 5. This is thought to be because the rinse liquids used in Comparative Examples 2 to 5 were not the specific organic treatment liquids defined in the present invention and therefore did not wet and spread uniformly over the resist film. [Industrial Applicability]

[0428] According to the present invention, it is possible to provide a pattern forming method capable of obtaining a pattern with excellent in-plane uniformity of line width, and a method for manufacturing an electronic device including the pattern forming method.

[0429] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on January 22, 2021 (Patent Application No. 2021-9169) and a Japanese patent application filed on July 21, 2021 (Patent Application No. 2021-120391), the contents of which are incorporated herein by reference.

Claims

1. An organic treatment liquid containing butyl acetate and a hydrocarbon having 11 or more carbon atoms, the content of the butyl acetate in the organic treatment liquid is 65% by mass or more and 95% by mass or less, and the content of the hydrocarbon having 11 or more carbon atoms is 5% by mass or more and 35% by mass or less, The organic processing liquid, wherein the hydrocarbon having 11 or more carbon atoms is an alkane having 11 to 15 carbon atoms.

2. 2. The organic processing liquid according to claim 1, wherein the hydrocarbon having 11 or more carbon atoms is undecane or dodecane.

3. 2. The organic processing liquid according to claim 1, wherein the organic processing liquid contains two or more types of hydrocarbons having 11 or more carbon atoms.

4. 2. The organic treatment liquid according to claim 1, wherein the content of the butyl acetate in the organic treatment liquid is 80% by mass or more and 95% by mass or less, and the content of the hydrocarbon having 11 or more carbon atoms in the organic treatment liquid is 5% by mass or more and 20% by mass or less.

5. 2. The organic processing liquid according to claim 1, wherein the organic processing liquid is used for developing or rinsing a resist film.

6. 2. The organic processing liquid according to claim 1, wherein the organic processing liquid is used for developing a resist film.

7. 2. The organic processing liquid according to claim 1, wherein the content of impurities contained in the organic processing liquid is 1 mass ppm (parts per million) or less.

8. 2. The organic processing liquid according to claim 1, wherein the organic processing liquid contains a conductive compound.

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