Pattern forming methods and electronic component manufacturing methods

Abstract

The present invention provides a pattern forming method that can obtain a pattern with excellent in-plane uniformity of linewidth, and a method for manufacturing an electronic component including the pattern forming method, by means of the following pattern forming method and a method for manufacturing an electronic component including the pattern forming method. The pattern forming method includes: (1) a step of forming a film using a photosensitive or radiosensitive linear resin composition, wherein the photosensitive or radiosensitive linear resin composition includes a resin (A) that decomposes and increases in polarity by the action of acid, and a compound (B) that generates acid by irradiation with photosensitive rays or radiation; (2) a step of exposing the film; and (3) a step of developing and rinsing the exposed film using an organic processing liquid containing butyl acetate and hydrocarbons having 11 or more carbon atoms, wherein the content of the hydrocarbons having 11 or more carbon atoms in the organic processing liquid is 1% by mass or more and 35% by mass or less.

Description

[Technical Field]

[0001] This invention relates to a pattern forming method and a method for manufacturing electronic components. More specifically, this invention relates to a pattern forming method and a method for manufacturing electronic components that can be preferably used in manufacturing processes of very large-scale integrated circuits (LSI) and high-capacity microchips, nanoimprint dies fabrication processes, and high-density information recording media, as well as other photofabrication processes. [Previous Technology]

[0002] Previously, in the manufacturing processes of semiconductor devices such as integrated circuits (ICs) or LSIs, microfabrication has been performed using photoresist compositions. In recent years, with the increasing integration of integrated circuits, there has been a demand for forming ultra-fine patterns in submicron or quarter-micron regions. Along with this, the exposure wavelength has also shown a trend towards shorter wavelengths, from gamma rays to i-rays, and further to KrF excimer laser light. Currently, exposure machines using ArF excimer lasers with a wavelength of 193 nm as the light source are under development. Furthermore, as a technique to further improve resolution, the so-called immersion method, which involves filling the space between the projection lens and the sample with a high-refractive-index liquid (hereinafter also referred to as "immersion liquid"), has been under development for some time.

[0003] In addition, lithography is currently being developed that utilizes electron beams (EB), X-rays, and extreme ultraviolet (EUV) light, in addition to excimer laser light. Along with this, chemically amplified resist compositions that effectively sense various types of radiation and possess excellent sensitivity and resolution are being developed.

[0004] For example, Patent Document 1 describes a pattern forming method that uses an organic processing solution with an oxidant content within a specific range to develop or clean (rinse) a photoresist film. Patent Document 2 describes a pattern forming method that uses a negatively amplified chemical photoresist composition negatively transformed by a crosslinking reaction to form a photoresist film, and after exposure, develops it using a developer containing an organic solvent that meets specific conditions. Furthermore, Patent Document 3 describes a pattern forming method that exposes a photoresist film containing a resin having acid-degradable repeating units, and develops it using a developer containing an organic solvent, wherein the acid-degradable repeating units are decomposed by the action of acid to produce an acid with a pKa within a specific range. [Prior Art Documents] [Patent Documents]

[0005] Patent Document 1: International Publication No. 2016 / 104565; Patent Document 2: Japanese Patent Application Publication No. 2011-065105; Patent Document 3: International Publication No. 2016 / 158711 [Summary of the Invention]

[0006] [Problem to be Solved by the Invention] As described in Patent Documents 1 to 3, the use of organic solvents for developing or rinsing in pattern forming methods has been known for the past. However, according to the research of the inventors, particularly for resist films formed using polar-conversion resist compositions containing acid-degrading resins and photoacid generators, there is room for improvement in the in-plane uniformity of the linewidth of the resulting pattern when using conventional developing or rinsing solutions containing organic solvents.

[0007] Therefore, the object of the present invention is to provide a pattern forming method that can obtain a pattern with excellent in-plane uniformity of linewidth, and a method for manufacturing an electronic component including the pattern forming method. [Means for Solving the Problem]

[0008] The inventors have discovered that the aforementioned problem can be solved by the following structure.

[0009] 〔1〕A pattern forming method comprising: (1) forming a film using a photosensitive or radiosensitive linear resin composition, the photosensitive or radiosensitive linear resin composition comprising a resin (A) that decomposes and increases in polarity by the action of an acid, and a compound (B) that generates an acid by irradiation with photosensitive rays or radiation; (2) exposing the film; and (3) developing and rinsing the exposed film using an organic processing solution containing butyl acetate and a hydrocarbon having 11 or more carbon atoms, wherein the content of the hydrocarbon having 11 or more carbon atoms in the organic processing solution is 1% by mass or more and 35% by mass or less. 〔2〕The pattern forming method of 〔1〕 wherein the hydrocarbon having 11 or more carbon atoms is undecane. [3] The pattern forming method as described in [1] or [2], wherein the resin (A) that decomposes and increases in polarity by the action of acid comprises at least one group selected from the group consisting of a group that substitutes a hydrogen atom of a carboxyl group with a release group that is released by the action of acid, a group that substitutes a hydrogen atom of an alcoholic hydroxyl group with a release group that is released by the action of acid, and a group that substitutes a hydrogen atom of a phenolic hydroxyl group with a release group that is released by the action of acid. [4] The pattern forming method as described in any one of [1] to [3], wherein the resin (A) that decomposes and increases in polarity by the action of acid has repeating units represented by the following general formula (AX).

[0010] [Chemical 1]

[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. The two Rx1 to Rx3 groups can be bonded to form a ring. [5] The pattern forming method according to any one of [1] to [4], wherein the resin (A) that decomposes and becomes more polar by the action of an acid has at least one selected from the group consisting of lactone groups, carbonate groups, sulopentalide groups, and cyclic groups having hydroxyl groups. [6] The pattern forming method according to any one of [1] to [5], wherein the resin (A) that decomposes and becomes more polar by the action of an acid has a repeating unit represented by the following general formula (Y).

[0012] [Chemical 2]

[0013] In general formula (Y), A represents a hydrogen atom, alkyl, cycloalkyl, halogen atom, or cyano. L represents a single bond or a divalent linkage having an oxygen atom. R represents a halogen atom, alkyl, cycloalkyl, aryl, alkenyl, aralkyl, alkoxy, alkylcarbonyloxy, alkylsulfonyloxy, alkyloxycarbonyl, or aryloxycarbonyl, which may be the same or different when multiple are present. When multiple R are present, they may form a ring together. a represents an integer from 1 to 3. b represents an integer from 0 to (5-a). 〔7〕The pattern forming method as described in any one of 〔1〕 to 〔6〕, wherein the compound (B) that produces an acid by irradiation with photochemical rays or radiation has a cation represented by the following general formula (ZaI) or a cation represented by the following general formula (ZaII).

[0014] [Chemical 3]

[0015] In general formula (ZaI), R201, R202, and R203 each independently represent an organic group. In general formula (ZaII), R204 and R205 each independently represent an organic group. [8] The pattern forming method as described in [7], wherein at least one of R201, R202, and R203 in general formula (ZaI) is an aryl group, or at least one of R204 and R205 in general formula (ZaII) is an aryl group. [9] The pattern forming method as described in [7] or [8], wherein at least one of R201, R202, and R203 in general formula (ZaI) has an acid-decomposable group, or at least one of R204 and R205 in general formula (ZaII) has an acid-decomposable group.

[10] The pattern forming method according to any one of [1] to [9], wherein the molecular weight of the acid produced by the compound (B) that produces acid by irradiation with photochemical rays or radiation is 250 or more.

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

[10] , wherein the content of the compound (B) that produces acid by irradiation with photochemical rays or radiation is 10% by mass or more relative to all solid components of the photosensitive or radiosensitive linear resin composition.

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

[11] , wherein the photosensitive or radiosensitive linear resin composition contains two or more of the compounds (B) that produce acid by irradiation with photochemical rays or radiation, or the compound (B) that produces acid by irradiation with photochemical rays or radiation is at least one selected from the group consisting of the following compounds (I) and the following compounds (II). Compound (I): A compound having one or more structural sites X and one or more structural sites Y, and which produces an acid upon irradiation by photochemical rays or radiation, wherein the acid comprises a first acidic site derived from structural site X and a second acidic site derived from structural site Y. Structural site X: A structural site comprising an anionic site A1- and a cation site M1+, and which forms a first acidic site represented by HA1 upon irradiation by photochemical rays or radiation. Structural site Y: A structural site comprising an anionic site A2- and a cation site M2+, and which forms a second acidic site represented by HA2 upon irradiation by photochemical rays or radiation. Wherein, compound (I) satisfies the following condition I.Condition I: In the compound (I), the compound PI formed by replacing the cation M1+ in the structural site X and the cation M2+ in the structural site Y with H+ has an acid dissociation constant a1 derived from the acidic site represented by HA1, which is formed by replacing the cation M1+ in the structural site X with H+, and an acid dissociation constant a2 derived from the acidic site represented by HA2, which is formed by replacing the cation M2+ in the structural site Y with 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 sites X and one or more of the following structural sites Z and producing an acid by irradiation with photochemical rays or radiation, the acid comprising two or more of the first acidic sites derived from the structural sites X and the structural sites Z. Structural site Z: A site capable of neutralizing the nonionic nature of an acid

[13] A method for manufacturing an electronic component, comprising a pattern forming method as described in any one of [1] to

[12] . [Effects of the invention].

[0016] According to the present invention, a pattern forming method that can obtain a pattern with excellent in-plane uniformity of line width and a method for manufacturing an electronic component including the pattern forming method can be provided.

Implementation Method

[0017] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below is sometimes based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. Regarding the use of the term "base group" in this specification, without departing from the spirit of the present invention, the terms "unsubstituted" and "unsubstituted" also include base groups without substituents and base groups containing substituents. For example, the term "alkyl" includes not only unsubstituted alkyl groups (unsubstituted alkyl groups) but also substituted alkyl groups (substituted alkyl groups). Furthermore, in this specification, the term "organic group" refers to a group containing at least one carbon atom. Unless otherwise specified, monovalent substituents are preferred as substituents.

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

[0019] Unless otherwise specified, the bonding orientation of the divalent groups described in this specification is not limited. For example, in the case where Y in the compound represented by the formula "XYZ" is -COO-, Y can be -CO-O- or -O-CO-. In addition, the compound can be "X-CO-OZ" or "XO-CO-Z".

[0020] In this specification, (meth)acrylate refers to acrylate and methacrylate, and (meth)acrylic acid refers to acrylic acid and methacrylic acid. In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersion (hereinafter also referred to as "molecular weight distribution") (Mw / Mn) are defined as the polystyrene conversion values ​​obtained by GPC determination using a gel permeation chromatography (GPC) apparatus (Tosoh HLC-8120GPC, solvent: tetrahydrofuran, flow rate (sample injection volume): 10 μL, column: Tosoh TSK gel Multipore HXL-M, 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 aqueous solution, specifically a value obtained by calculation using the software package described below, based on a database of Hammett substituent constants and known literature values. All pKa values ​​described in this specification represent values ​​obtained by calculation using the software package described above. Software package 1: Advanced Chemistry Development (ACD / Labs) Solaris System Software V8.14 (1994-2007 ACD / Labs).

[0022] Alternatively, pKa can also be determined using molecular orbital calculations. One specific method is the calculation of the H+ dissociation free energy in aqueous solution based on thermodynamic cycles. Methods for calculating the H+ dissociation free energy include density functional theory (DFT), and various other methods have been reported in the literature; we are not limited to any particular method. Furthermore, several software programs exist that can perform DFT, such as Gaussian16.

[0023] In this specification, pKa generally refers to the value obtained by using software package 1 and calculating a database of substituent constants based on Hammett and known literature values. If pKa cannot be calculated using this method, it is assumed to be the value obtained using density functional theory (DFT) and Gaussian 16. Furthermore, in this specification, pKa generally refers to "pKa in aqueous solution." If pKa in aqueous solution cannot be calculated, it is assumed to be "pKa in dimethyl sulfoxide (DMSO) solution."

[0024] 〔Pattern Forming Method〕 The pattern forming method of the present invention includes: (1) a step of forming a film using a photosensitive or radiosensitive linear resin composition, wherein the photosensitive or radiosensitive linear resin composition comprises a resin (A) that decomposes and increases in polarity by the action of an acid, and a compound (B) that generates an acid by irradiation with photosensitive rays or radiation; (2) a step of exposing the film; (3) a step of developing and rinsing the exposed film using an organic processing liquid containing butyl acetate and hydrocarbons having 11 or more carbon atoms, wherein the content of the hydrocarbons having 11 or more carbon atoms in the organic processing liquid is 1% by mass or more and 35% by mass or less.

[0025] While the details of the mechanism by which the pattern forming method of the present invention can obtain patterns with excellent in-plane uniformity of linewidth are not clear, the inventors speculate as follows. Compared to films formed from photosensitive or radiosensitive linear resin compositions comprising a resin (A) that decomposes under the action of acid and increases in polarity, and a compound (B) that generates acid upon irradiation by photochemical rays or radiation, organic processing solutions containing a specific structure having a content of butyl acetate and hydrocarbons having 11 or more carbon atoms of 1% by mass or more and 35% by mass or less of such hydrocarbons are considered to have excellent affinity. Therefore, it is believed that by using the organic processing solution for at least one of development and rinsing, the organic processing solution uniformly wets and diffuses across the entire wafer, thereby improving the in-plane uniformity of linewidth.

[0026] The process of each step is described in detail below.

[0027] <Step (1)> Step (1) is a step of forming a film using a photosensitive or radiosensitive linear resin composition, which includes a resin (A) that decomposes and increases in polarity by the action of acid, and a compound (B) that generates acid by irradiation with photosensitive rays or radiation. The photosensitive or radiosensitive linear resin composition used in step (1) is typically a photoresist composition, and will be referred to as a "photoresist composition" below. In addition, the film formed using the photosensitive or radiosensitive linear resin composition is typically a photoresist film, and will be referred to as a "photoresist film" below. Details about the photosensitive or radiosensitive linear resin composition will be described later.

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

[0029] As a method for forming a resist film on a substrate using a resist composition, a method of coating the resist composition on the substrate can be cited as an example. Furthermore, it is preferable to filter the resist composition as needed before coating. 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. Additionally, 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) used in the manufacture of integrated circuit devices by a suitable coating method such as a spin coater or a coating machine. Spin coating using a spin coater is preferred. The rotation speed when using a spin coater is preferably 1000 rpm to 3000 rpm. After the resist composition is applied, the substrate can be dried to form a resist film. Furthermore, various substrate films (inorganic films, organic films, anti-reflective films) can be formed on the underside of the resist film as needed.

[0031] As a drying method, methods of drying by heating can be listed, for example. Heating can be carried out by a mechanism equipped in a conventional exposure machine and / or developing machine, or by using a heating plate, etc. The heating temperature is preferably 80°C to 150°C, more preferably 80°C to 140°C, and even more preferably 80°C to 130°C. The heating time is preferably 30 seconds to 1000 seconds, more preferably 60 seconds to 800 seconds, and even more preferably 60 seconds to 600 seconds.

[0032] The thickness of the resist film is not particularly limited, but it is preferably 10 nm to 120 nm in order to form finer patterns with higher precision. Specifically, when using EUV exposure, the thickness of the resist film is more preferably 10 nm to 65 nm, and even more preferably 15 nm to 50 nm. Furthermore, when using ArF immersion exposure, the thickness of the resist film is more preferably 10 nm to 120 nm, and even more preferably 15 nm to 90 nm.

[0033] Furthermore, a topcoat can be formed on the top of the resist film using a topcoat composition. Preferably, the topcoat composition is unmixed with the resist film, thus allowing for uniform coating on the top of the resist film. The topcoat is not particularly limited, and can be formed using previously known methods, for example, based on paragraphs

[0072] to

[0082] of Japanese Patent Application Publication No. 2014-059543. For example, it is preferable to form a topcoat on the resist film containing an alkaline compound as described in Japanese Patent Application Publication No. 2013-61648. Specific examples of alkaline compounds that may be contained in the topcoat include alkaline compounds that may be contained in the resist composition. Additionally, the topcoat is also preferably a compound containing at least one group or bond selected from the group consisting of ether bonds, thioether bonds, hydroxyl groups, thiols, carbonyl bonds, and ester bonds.

[0034] <Step (2)> Step (2) is a step of exposing the resist film. As an exposure method, a method of irradiating the formed resist film with photochemical rays or radiation through a specified mask can be listed. As photochemical rays or radiation, the following can be listed: infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. Far ultraviolet light with a wavelength of less than 250 nm, more preferably less than 220 nm, and particularly preferably 1 nm to 200 nm can be listed. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm), EUV (13 nm), X-rays, and electron beams can be listed.

[0035] It is preferable to perform baking (heating) after exposure and before development. Baking promotes the reaction of the exposed part, resulting in better sensitivity and pattern shape. The heating temperature is preferably 80°C to 150°C, more preferably 80°C to 140°C, and even more preferably 80°C to 130°C. The heating time is preferably 10 seconds to 1000 seconds, more preferably 10 seconds to 180 seconds, and even more preferably 30 seconds to 120 seconds. Heating can be performed using a mechanism equipped in a conventional exposure machine and / or developing machine, or using a heating plate, etc. This step is also called post-exposure baking.

[0036] <Step (3)> Step (3) is a step of developing and rinsing the resist film exposed in step (2) using an organic processing solution containing butyl acetate and hydrocarbons having 11 or more carbon atoms. The content of the hydrocarbons having 11 or more carbon atoms in the organic processing solution 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 hydrocarbons with 11 or more carbon atoms. The hydrocarbons with 11 or more carbon atoms are preferably alkanes, more preferably alkanes with 11 to 15 carbon atoms, and even more preferably alkanes with 11 to 13 carbon atoms, particularly undecane or dodecane, and most preferably undecane. Furthermore, if structural isomers of hydrocarbons with 11 or more carbon atoms, such as undecane or dodecane, exist, structural isomers may also be included. The organic treatment liquid may contain only one type of hydrocarbon with 11 or more carbon atoms, or it may contain two or more types. Taking the total organic treatment liquid as 100% by mass, the content of hydrocarbons with 11 or more carbon atoms in the organic treatment liquid (in the case of multiple hydrocarbons with 11 or more carbon atoms, this is the total amount) is 1% by mass or more and 35% by mass or less, preferably 5% by mass or more and 30% by mass or less, and even more preferably 10% by mass or more and 25% by mass or less.

[0038] The organic treatment liquid used in step (3) contains butyl acetate (n-butyl acetate). The total organic treatment liquid is set to 100% by mass. 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.

[0039] The organic treatment liquid may also contain other components besides butyl acetate and hydrocarbons with 11 or more carbon atoms. Examples of other components include surfactants, antioxidants, and alkaline compounds. If the total organic treatment liquid is set at 100% by mass, 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, further preferably 0% by mass or more and 0.5% by mass or less, and most preferably 0% by mass or less (i.e., it does not contain other components).

[0040] Step (3) is a step of developing and rinsing (cleaning) the resist film exposed in step (2) using the organic processing solution. In step (3), only development, only rinsing, or both development and rinsing may be performed. Hereinafter, the case of developing in step (3) (hereinafter, the step of developing using the organic processing solution will also be referred to as step (3A)) and the case of rinsing in step (3) (hereinafter, the step of rinsing using the organic processing solution will also be referred to as step (3B)) will be described. Step (3) may be a step that includes only step (3A), a step that includes only step (3B), or a step that includes both steps (3A) and (3B). Furthermore, when step (3) includes both steps (3A) and (3B), the organic processing solution used as the developing solution in step (3A) and the organic processing solution used as the rinsing solution in step (3B) may be the same or different. A preferred embodiment of the present invention is an organic treatment solution containing butyl acetate and undecane, wherein the "butyl acetate / undecane" ratio is "90 / 10" by mass, as the rinsing solution.

[0041] 〔Step (3A)〕 The case of developing by means of the organic processing solution in step (3) (step (3A)) will be described. In step (3A), the organic processing solution is used as the developing solution.

[0042] Examples of developing methods include: immersing the substrate in a tank filled with developing solution for a fixed time (immersion method); using surface tension to accumulate developing solution on the substrate surface and allowing it to stand for a fixed time for development (puddle method); spraying developing solution onto the substrate surface (spray method); and continuously spraying developing solution onto a substrate rotating at a fixed speed while scanning the developing solution nozzle at a fixed speed (dynamic distribution method). Additionally, after the developing step, a step can be performed to stop developing by replacing the solvent with another solvent. The developing time is not particularly limited as long as it is the time required for the resin in the desired removal portion to fully dissolve; preferably, it is 10 to 300 seconds, more preferably 20 to 120 seconds. The temperature of the developing solution is preferably 0°C to 50°C, more preferably 15°C to 35°C.

[0043] A resist pattern (also referred to simply as "pattern") is formed by performing step (3A). It is preferable to perform rinsing after performing step (3A). Rinsing can also be performed by step (3B) described later, and can also be performed using a rinsing solution other than the organic processing solution. There are no particular limitations on the rinsing solution other than the organic processing solution, as long as it does not dissolve the pattern; a solution containing a common organic solvent can be used. The rinsing solution other than the organic processing solution is preferably an organic solvent containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. When rinsing is performed using a rinsing solution other than the organic processing solution, the rinsing method can be the same as the rinsing method in step (3B) described later.

[0044] [Step (3B)] The case of rinsing with the organic treatment solution in step (3) (step (3B)) will be described. In step (3B), the organic treatment solution is used as the rinsing solution.

[0045] There is no particular limitation on the rinsing method. For example, the following methods can be listed: continuously spraying rinsing liquid onto a substrate rotating at a fixed speed (spin coating method), immersing the substrate in a tank filled with rinsing liquid for a fixed time (immersion method), and spraying rinsing liquid onto the surface of the substrate (spraying method).

[0046] It is preferable to perform development before step (3B). Development can also be performed by the aforementioned step (3A), or by using a developer other than the organic processing solution. As a developer other than the organic processing solution, an organic developer is preferred. When developing with a developer other than the organic processing solution, the development method can be the same as the development method in the aforementioned step (3A).

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

[0048] The organic solvent can be mixed with multiple solvents, or with solvents other than those mentioned above, or with water. The water content of the overall developer is preferably less than 50% by mass, more preferably less than 20% by mass, even more preferably less than 10% by mass, and most preferably substantially free of water. Relative to the total amount of the developer, the content of the organic solvent relative to the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and most preferably 95% by mass or more and 100% by mass or less.

[0049] In addition, the pattern forming 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 inside the pattern. Furthermore, this step also anneales the resist pattern and improves the surface roughness of the pattern. The heating step after the rinsing step is typically performed at 40°C to 250°C (preferably 90°C to 200°C) for a typical duration of 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

[0050] Alternatively, the formed pattern can also be used as a mask to perform etching on the substrate. That is, the pattern formed in step (3) can also be used as a mask to process the substrate (or the underlayer film and substrate) to form a pattern on the substrate. There is no particular limitation on the processing method of the substrate (or the underlayer film and substrate), but it is preferable to form a pattern on the substrate by dry etching of the substrate (or the underlayer film and substrate) using the pattern formed in step (3) as a mask. Dry etching is preferably oxygen plasma etching.

[0051] The organic processing liquid, resist composition, and other materials (e.g., solvent, developer, rinsing liquid, composition for forming antireflective film, composition for forming top coating, etc.) used in the pattern forming method of the present invention preferably do not contain impurities such as metals. The content of impurities contained in these materials is preferably 1 ppm (parts per million) or less, more preferably 10 ppb (parts per billion) or less, further preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably 1 ppt or less. There is no particular limitation on the lower limit, but it is preferably 0 ppt or more. Examples of metallic impurities include, for example: Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn.

[0052] As a method for removing impurities such as metals from various materials, filtration using a filter can be cited as an example. Details of filtration using a filter are described in paragraph

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

[0053] In addition, as a method to reduce impurities such as metals contained in various materials, the following methods can be listed for example: selecting raw materials with low metal content as raw materials for constituting various materials, filtering the raw materials constituting various materials with filters, and lining the device with Teflon (registered trademark) and distilling under conditions that suppress contamination as much as possible.

[0054] In addition to filtration by a filter, impurities can also be removed using an adsorbent material, or a combination of filtration and adsorbent material can be used. As the adsorbent material, known adsorbent materials can be used, such as inorganic adsorbent materials like silicone and zeolite, and organic adsorbent materials like activated carbon. To reduce impurities such as metals contained in the aforementioned materials, it is necessary to prevent the introduction of metal impurities during the manufacturing process. The content of metal components contained in the cleaning solution used to clean the manufacturing apparatus can be measured to confirm whether metal impurities have been sufficiently removed from the manufacturing apparatus. The content of metal components 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 limitation on the lower limit, but it is preferably 0 ppt by mass or more.

[0055] To prevent malfunctions in the chemical solution piping and various components (filters, O-rings, and tubes, etc.) caused by static electricity and subsequent electrostatic discharge, conductive compounds may be added to organic processing solutions such as rinsing solutions. There are no particular limitations on the conductive compounds; methanol is an example. There are no particular limitations on the amount added, but for maintaining better developing or rinsing characteristics, it is preferably 10% by mass or less, more preferably 5% by mass or less. There are no particular limitations on the lower limit, but it is preferably 0.01% by mass or more. For chemical solution piping, various pipes coated with SUS (stainless steel), or polyethylene, polypropylene, or fluoropolymers (polytetrafluoroethylene, or perfluoroalkoxy resins, etc.) that have undergone antistatic treatment can be used, for example. Similarly, polyethylene, polypropylene, or fluoropolymers (polytetrafluoroethylene, or perfluoroalkoxy resins, etc.) that have undergone antistatic treatment can also be used for filters and O-rings.

[0056] [Photosensitive or radiosensitive linear resin composition] The photosensitive or radiosensitive linear resin composition used in this invention will be described. The photosensitive or radiosensitive linear resin composition used in this invention (also referred to as "resist composition") comprises a resin (A) that decomposes and increases in polarity by the action of acid (also referred to as "acid-decomposing resin" or "resin (A)"), and a compound (B) that generates acid by irradiation with photosensitive rays or radiation (also referred to as "photoacid generator" or "compound (B)").

[0057] The resist composition is preferably a negative resist composition. Furthermore, the resist composition is preferably a resist composition for organic solvent development. Typically, the resist composition is a chemically amplified resist composition.

[0058] [Acid-degradable resin (resin (A))] The resist composition includes resin (A). In the pattern forming method of the present invention, typically, when an organic developer is used as the developer, a negative pattern can be formed more preferably. Resin (A) generally contains a group that decomposes and increases in polarity by the action of acid (also called "acid-degradable group"). Preferably, it contains repeating units having acid-degradable groups. As repeating units having acid-degradable groups, in addition to the repeating units having acid-degradable groups described later, it is preferable to have repeating units having acid-degradable groups containing unsaturated bonds.

[0059] <Repetitive Unit with Acid-Decomposable Group> (Repetitive Unit with Acid-Decomposable Group) The acid-decomposable group is preferably a group that decomposes and generates a polar group by the action of an acid. The acid-decomposable group is preferably a structure with a release group that removes the polar group by the action of an acid. That is, the resin (A) preferably contains a repeating unit having a group that decomposes and generates a polar group by the action of an acid. The resin having this repeating unit becomes more polar by the action of an acid and its solubility relative to an alkaline developer increases, while its solubility relative to an organic solvent decreases. The polar group is preferably a base-soluble group, such as: carboxyl, phenolic hydroxyl, fluorinated alcohol, sulfonic acid, phosphoric acid, sulfonamide, sulfonimide, (alkylsulfonyl)(alkylcarbonyl)methylene, (alkylsulfonyl)(alkylcarbonyl)imide, bis(alkylcarbonyl)methylene, bis(alkylcarbonyl)imide, bis(alkylsulfonyl)methylene, bis(alkylsulfonyl)imide, tri(alkylcarbonyl)methylene, and tri(alkylsulfonyl)methylene, as well as acidic groups and alcoholic hydroxyl groups. The polar group is preferably a carboxyl, phenolic hydroxyl, fluorinated alcohol (preferably hexafluoroisopropanol), or sulfonic acid.

[0060] As a detaching group that is released by the action of an acid, examples include the groups represented by formulas (Y1) to (Y4). Formula (Y1): -C(Rx1)(Rx2)(Rx3) Formula (Y2): -C(=O)OC(Rx1)(Rx2)(Rx3) Formula (Y3): -C(R36)(R37)(OR38) Formula (Y4): -C(Rn)(H)(Ar

[0061] In formulas (Y1) and (Y2), Rx1 to Rx3 independently represent alkyl (straight-chain or branched), cycloalkyl (monocyclic or polycyclic), alkenyl (straight-chain or branched), or aryl (monocyclic or polycyclic). Furthermore, when all of Rx1 to Rx3 are alkyl (straight-chain or branched), it is preferable that at least two of Rx1 to Rx3 are methyl. Preferably, Rx1 to Rx3 independently represent straight-chain or branched alkyl groups, and more preferably, Rx1 to Rx3 independently represent straight-chain alkyl groups. The two of Rx1 to Rx3 can be bonded to form a monocyclic or polycyclic ring. The alkyl groups of Rx1 to Rx3 are preferably alkyl groups with 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tributyl. The cycloalkyl groups Rx1 to Rx3 are preferably monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl, or polycyclic cycloalkyl groups such as norbornyl, tetracyclic decyl, tetracyclic dodecyl, and adamantyl. The aryl groups Rx1 to Rx3 are preferably aryl groups having 6 to 10 carbon atoms, such as phenyl, naphthyl, and anthracene. The alkenyl groups Rx1 to Rx3 are preferably vinyl. The rings formed by the two bonds of Rx1 to Rx3 are preferably cycloalkyl groups. The cycloalkyl groups formed by the two bonds of Rx1 to Rx3 are preferably monocyclic cycloalkyl groups such as cyclopentyl or cyclohexyl, or polycyclic cycloalkyl groups such as norbornyl, tetracyclic decyl, tetracyclic dodecyl, or adamantyl, and more preferably monocyclic cycloalkyl groups having 5 to 6 carbon atoms. In the cycloalkyl group formed by the two bonds of Rx1 to Rx3, for example, one of the methylene groups constituting the ring may be substituted with a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylene group. Additionally, one or more of the ethyl groups constituting the cycloalkane ring in these cycloalkyl groups may be substituted with vinylene groups. The group represented by formula (Y1) or formula (Y2) is preferably in the form where Rx1 is methyl or ethyl, and Rx2 and Rx3 are bonded to form the cycloalkyl group. In the case of a resist composition, such as an EUV exposure resist composition, the alkyl group, cycloalkyl group, alkenyl group, aryl group represented by Rx1 to Rx3, and the ring formed by the two bonds of Rx1 to Rx3, are also preferably further substituents containing fluorine or iodine atoms.

[0062] In formula (Y3), R36 to R38 independently represent a hydrogen atom or a monovalent organic group. R37 and R38 can bond to each other to form a ring. Examples of monovalent organic groups include alkyl, cycloalkyl, aryl, aralkyl, and alkenyl. R36 is also preferably a hydrogen atom. Furthermore, the alkyl, cycloalkyl, aryl, and aralkyl groups may contain heteroatoms such as oxygen atoms and / or groups containing heteroatoms such as carbonyl groups. For example, one or more of the alkyl, cycloalkyl, aryl, and aralkyl groups, such as methylene, may be substituted with heteroatoms such as oxygen atoms and / or groups containing heteroatoms such as carbonyl groups. In addition, R38 can also bond to other substituents in the main chain of the repeating unit to form a ring. The group formed by R38 bonding to other substituents in the main chain of the repeating unit is preferably an alkyl group such as methylene. In the case of a resist composition, such as a resist composition for EUV exposure, the monovalent organic groups represented by R36 to R38 and the ring formed by the mutual bonding of R37 and R38 are preferably further substituents with fluorine or iodine atoms.

[0063] As for formula (Y3), it is preferred to be the basis represented by the following formula (Y3-1).

[0064] [Chemical 4]

[0065] Here, L1 and L2 independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group composed of these (e.g., a group composed of an alkyl group and an aryl group). M represents a single bond or a divalent linked group. Q represents an alkyl group that may contain heteroatoms, a cycloalkyl group that may contain heteroatoms, an aryl group, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group that may contain heteroatoms, or a group composed of these (e.g., a group composed of an alkyl group and a cycloalkyl group). One of the alkyl and cycloalkyl groups, for example, the methylene group, may be substituted with a heteroatom such as an oxygen atom, or a group containing a heteroatom such as a carbonyl group. Furthermore, it is preferred that 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 composed of an alkyl group and an aryl group. At least two of Q, M, and L1 can be bonded to form a ring (preferably a 5-membered ring or a 6-membered ring). Regarding the refinement of the pattern, L2 is preferably a secondary or tertiary alkyl group, more preferably a tertiary alkyl group. Examples of secondary alkyl groups include isopropyl, cyclohexyl, or norbornyl, while examples of tertiary alkyl groups include tributyl or adamantyl. In these states, due to the increased Tg (glass transition temperature) and activation energy, fogging can be suppressed in addition to ensuring film strength.

[0066] In the case of a resist composition, such as a resist composition for EUV exposure, the alkyl, cycloalkyl, aryl, and groups formed by combining these groups, represented by L1 and L2, are preferably further substituents containing fluorine or iodine atoms. Furthermore, it is also preferable that the alkyl, cycloalkyl, aryl, and aralkyl groups contain heteroatoms such as oxygen atoms in addition to fluorine and iodine atoms (i.e., one of the alkyl, cycloalkyl, aryl, and aralkyl groups, for example, a methylene group, is substituted with a heteroatom such as an oxygen atom, or a group containing a heteroatom such as a carbonyl group). Additionally, in the case of a resist composition, such as a resist composition for EUV exposure, the heteroatom in the alkyl, cycloalkyl, aryl, amino, ammonium, mercapto, cyano, aldehyde, and groups formed by combining these groups, which may contain heteroatoms, is preferably selected from the group consisting of fluorine, iodine, and oxygen atoms.

[0067] In formula (Y4), Ar represents an aromatic cyclic group. Rn represents an alkyl, cycloalkyl, or aryl group. Rn and Ar can bond to each other to form a non-aromatic ring. Ar is preferably an aryl group. In the case of a resist composition, such as a resist composition for EUV exposure, the aromatic cyclic group represented by Ar, and the alkyl, cycloalkyl, and aryl groups represented by Rn are preferably substituents having fluorine and iodine atoms.

[0068] In terms of the excellent acid decomposability of the repeating unit, in the case of the non-aromatic ring directly bonded to the polar group (or its residue) in the detaching group protecting the polar group, the ring member atom adjacent to the ring member atom directly bonded to the polar group (or its residue) in the non-aromatic ring is preferably not a halogen atom such as a fluorine atom as a substituent.

[0069] The detaching group that is released by the action of acid can also be 2-cyclopentenyl with a substituent (alkyl group, etc.) such as 3-methyl-2-cyclopentenyl, and cyclohexyl with a substituent (alkyl group, etc.) such as 1,1,4,4-tetramethylcyclohexyl.

[0070] The resin (A) comprises at least one group selected from the group consisting of a group that substitutes a hydrogen atom of a carboxyl group with a dissociation group that is removed by acid, a group that substitutes a hydrogen atom of an alcoholic hydroxyl group with a dissociation group that is removed by acid, and a group that substitutes a hydrogen atom of a phenolic hydroxyl group with a dissociation group that is removed by acid.

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

[0072] [Chemical 5]

[0073] L1 represents a divalent linker that may have a fluorine atom or an iodine atom, R1 represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group that may have a fluorine atom or an iodine atom, or an aryl group that may have a fluorine atom or an iodine atom, and R2 represents a releasable group that is released by the action of an acid and may have a fluorine atom or an iodine atom. At least one of L1, R1, and R2 has a fluorine atom or an iodine atom. L1 represents a divalent linker that may have a fluorine atom or an iodine atom. Examples of divalent linkers that may have a fluorine atom or an iodine atom include: -CO-, -O-, -S-, -SO-, -SO2-, hydrocarbon groups that may have a fluorine atom or an iodine atom (e.g., alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, etc.), and linkers formed by multiple such linkages. Wherein, L1 is preferably -CO-, aryl, or -aryl-aryl-alkyl group having fluorine or iodine atoms, more preferably -CO- or -aryl-aryl-aryl-aryl group having fluorine or iodine atoms. As an aryl group, phenyl is preferred. The aryl group can be linear or branched. The number of carbon atoms in the aryl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 3. The total number of fluorine and iodine atoms contained in the aryl group having fluorine or iodine atoms is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0074] R1 represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group that may have fluorine or iodine atoms, or an aryl group that may have fluorine or iodine atoms. 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, more preferably 1 to 3. The total number of fluorine and iodine atoms contained in the alkyl group having fluorine or iodine atoms 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 heteroatoms such as oxygen atoms other than halogen atoms.

[0075] R2 represents a detaching group that is released by the action of an acid and may have a fluorine atom or an iodine atom. Examples of detaching groups that may have a fluorine atom or an iodine atom include those represented by the formulas (Y1) to (Y4) and have a fluorine atom or an iodine atom.

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

[0077] [Chemical 6]

[0078] In the general formula (AI), Xa1 represents a hydrogen atom or an alkyl group. T represents a single bond or a divalent linkage. Rx1 to Rx3 independently represent alkyl, cycloalkyl, alkenyl, or aryl groups, respectively. The two Rx1 to Rx3 can be bonded together to form a ring.

[0079] The alkyl group represented by Xa1 can be linear or branched. Furthermore, the alkyl group may also have substituents. Examples of the alkyl group include methyl or a group represented by -CH2-R11. R11 represents a halogen atom (fluorine atom, etc.), a hydroxyl group, or a monovalent organic group, such as: an alkyl group with 5 or fewer carbon atoms that can be substituted by a halogen atom, an alkyl group with 5 or fewer carbon atoms that can be substituted by a halogen atom, and an alkoxy group with 5 or fewer carbon atoms that can be substituted by a halogen atom, preferably an alkyl group with 3 or fewer carbon atoms, and more preferably a methyl group. Xa1 is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0080] Examples of divalent linkers for T include: alkyl groups, aromatic cycloyl groups, -COO-Rt- groups, and -O-Rt- groups. In these formulas, Rt represents an alkyl group or an cycloalkyl 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 alkyl 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 Rx1 to Rx3 can be straight-chain or branched. Additionally, the alkyl groups may have substituents. Preferably, the alkyl groups are alkyl groups with 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tributyl. The cycloalkyl groups Rx1 to Rx3 can be monocyclic or polycyclic. Furthermore, the cycloalkyl groups may also have substituents. Preferably, the cycloalkyl groups are monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl, or polycyclic cycloalkyl groups such as norbornyl, tetracyclic decyl, tetracyclic dodecyl, and adamantyl. For example, one of the methylene groups constituting the ring in the cycloalkyl group may be substituted with a heteroatom such as an oxygen atom, a sulfur atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, one or more of the ethyl groups constituting the cycloalkane ring in these cycloalkyl groups may be substituted with vinylidenes. The aryl groups of Rx1 to Rx3 can be monocyclic or polycyclic. Additionally, the aryl groups may have substituents. Preferably, the aryl group has 6 to 10 carbon atoms, such as phenyl, naphthyl, and anthracene. The alkenyl groups of Rx1 to Rx3 can be linear or branched. Additionally, the alkenyl group may have substituents. Preferably, the alkenyl group is vinyl. When a ring is formed by the two bonds of Rx1 to Rx3, the formed ring can be monocyclic or polycyclic. Preferably, the formed ring is cycloalkyl. Preferably, the cycloalkyl group is monocyclic, such as cyclopentyl or cyclohexyl. Preferably, it is polycyclic, such as norbornyl, tetracyclodecyl, tetracyclododecyl, and adamantyl. Preferably, it is a monocyclic cycloalkyl group with 5 to 6 carbon atoms. In the cycloalkyl groups formed by the two bonds of Rx1 to Rx3, for example, one of the methylene groups constituting the ring may be 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 vinylene. In addition, one or more of the ethyl groups constituting the cycloalkane ring in these cycloalkyl groups may be substituted with vinylene.

[0082] When each of the groups has a substituent, the substituent is not particularly limited, and examples include: alkyl (1 to 4 carbon atoms, etc.), halogen atom, hydroxyl group, alkoxy (1 to 4 carbon atoms, etc.), alkylthio (1 to 4 carbon atoms, etc.), carboxyl group, and alkoxycarbonyl (2 to 6 carbon atoms, etc.). It is preferred that the number of carbon atoms in the substituent is 8 or less.

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

[0084] [Chemical 7]

[0085] In the general formula (AX), Xa1 represents a hydrogen atom or an alkyl group. Rx1 to Rx3 independently represent alkyl, cycloalkyl, alkenyl, or aryl groups, respectively. The two Rx1 to Rx3 groups can be bonded together to form a ring.

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

[0087] The repeating unit having an acid-decomposable group is preferably the repeating unit represented by the following general formula (AX2).

[0088] [Chemical 8]

[0089] In the general formula (AX2), Xa1 represents a hydrogen atom or an alkyl group. Rx1 to Rx3 independently represent alkyl, cycloalkyl, alkenyl, or aryl groups, respectively. The two Rx1 to Rx3 groups can bond together to form a ring. Ar represents a divalent aromatic hydrocarbon group.

[0090] In general formula (AX2), Xa1 has the same meaning as Xa1 in general formula (AI), and the specific examples and preferred ranges are also the same. In general formula (AX2), Rx1 to Rx3 have the same meaning as Rx1 to Rx3 in general formula (AI), and the specific examples and preferred ranges are also the same. In general formula (AX2), Ar is preferably an aryl group, more preferably an aryl group with 6 to 20 carbon atoms, further preferably an aryl group with 6 to 10 carbon atoms, and especially preferably an aryl group with 8 or fewer carbon atoms. Ar may have substituents, and examples of substituents include: alkyl (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, and alkoxycarbonyl groups (2 to 6 carbon atoms), etc., preferably those with 8 or fewer carbon atoms.

[0091] When resin (A) contains a group that substitutes the hydrogen atom of the phenolic hydroxyl group with a release group that is released by the action of acid, resin (A) is preferably a repeating unit containing a structure protected by a group represented by formula (Y1) to formula (Y4) with hydrogen atoms in the phenolic hydroxyl group.

[0092] The repeating unit, which is a group that substitutes the hydrogen atom of the phenolic hydroxyl group with a dissociation group that is removed by the action of an acid, is preferably a repeating unit represented by the following general formula (AII).

[0093] [Chemical 9]

[0094] In general formula (AII), R61, R62, and R63 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. R62 may also bond with Ar6 to form a ring, in which case R62 represents a single bond or an extended alkyl group. X6 represents a single bond, -COO-, or -CONR64-. R64 represents a hydrogen atom or an alkyl group. L6 represents a single bond or an extended alkyl group. Ar6 represents an aromatic hydrocarbon group with a valence of (n+1), and in the case of forming a ring with R62, represents an aromatic hydrocarbon group with a valence of (n+2). When n ≥ 2, Y2 each independently represents a hydrogen atom or a group that is released by the action of an acid. At least one of Y2 represents a group that is released by the action of an acid. Preferably, the groups that are released by the action of an acid for Y2 are those represented by formulas (Y1) to (Y4). n represents an integer from 1 to 4. Each of the groups may also have substituents, such as alkyl (1 to 4 carbons), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbons), carboxyl groups, and alkoxycarbonyl groups (2 to 6 carbons), with those having 8 or fewer carbons being preferred.

[0095] The content of repeating units having acid-decomposable groups is preferably 15 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, relative to all repeating units in resin (A). Furthermore, as an upper limit, it 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, relative to all repeating units in resin (A).

[0096] Specific examples of repeating units having acid-decomposable groups are shown below, but the present invention is not limited thereto. Furthermore, in the formula, Xa1 represents any one of H, CH3, CF3, and CH2OH, and Rxa and Rxb represent straight-chain or branched alkyl groups having 1 to 5 carbon atoms, respectively.

[0097] [Chemical 10]

[0098] [Chemical 11]

[0099] [Chemical 12]

[0100] [Chemistry 13]

[0101] [Chemical 14]

[0102] [Chemistry 15]

[0103] (Repeating unit having an acid-degradable group containing an unsaturated bond) Resin (A) may contain a repeating unit having an acid-degradable group containing an unsaturated bond. Preferably, the repeating unit having an acid-degradable group containing an unsaturated bond is the repeating unit represented by formula (B). Formula (B):

[0104] [Chemical 16]

[0105] In formula (B), Xb represents a hydrogen atom, a halogen atom, or an alkyl group that may have substituents. L represents a single bond or a divalent linker that may have substituents. Ry1 to Ry3 independently represent linear or branched alkyl groups, monocyclic or polycyclic cycloalkyl groups, alkenyl groups, alkynyl groups, or monocyclic or polycyclic aryl groups. At least one of Ry1 to Ry3 represents an alkenyl group, alkynyl group, monocyclic or polycyclic cycloalkenyl group, or monocyclic or polycyclic aryl group. Two of Ry1 to Ry3 can be bonded to form a monocyclic or polycyclic ring (monocyclic or polycyclic cycloalkyl, cycloalkenyl, etc.).

[0106] As the alkyl group represented by Xb, which may have substituents, examples include methyl or the group represented by -CH2-R11. R11 represents a halogen atom (fluorine atom, etc.), a hydroxyl group, or a monovalent organic group, for example: an alkyl group with 5 or fewer carbon atoms that can be substituted by a halogen atom, an alkoxy group with 5 or fewer carbon atoms that can be substituted by a halogen atom, and an alkoxy group with 5 or fewer carbon atoms that can be substituted by a halogen atom, preferably an alkyl group with 3 or fewer carbon atoms, and more preferably a methyl group. As Xb, it is more preferably a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0107] Examples of divalent linkers for L include: -Rt-, -CO-, -COO-Rt-, -COO-Rt-CO-, -Rt-CO-, and -O-Rt-. In these formulas, Rt represents an alkyl group, an cycloalkyl group, or an aromatic cycloalkyl group, preferably an aromatic cycloalkyl group. The L group is preferably -Rt-, -CO-, -COO-Rt-CO-, or -Rt-CO-. Rt may, for example, have substituents such as halogen atoms, hydroxyl groups, or alkoxy groups. An aromatic group is preferred.

[0108] The alkyl group of Ry1 to Ry3 is preferably an alkyl group with 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tributyl. The cycloalkyl group of Ry1 to Ry3 is preferably a monocyclic cycloalkyl group such as cyclopentyl and cyclohexyl, or a polycyclic cycloalkyl group such as norbornyl, tetracyclic decyl, tetracyclic dodecyl, and adamantyl. The aryl group of Ry1 to Ry3 is preferably an aryl group with 6 to 10 carbon atoms, such as phenyl, naphthyl, and anthracene. The alkenyl group of Ry1 to Ry3 is preferably vinyl. The alkynyl group of Ry1 to Ry3 is preferably ethynyl. The cycloalkenyl group of Ry1 to Ry3 is preferably a cycloalkyl group containing a double bond in part of a monocyclic cycloalkyl group such as cyclopentyl and cyclohexyl. The cycloalkyl group formed by the two bonds of Ry1 to Ry3 is preferably a monocyclic cycloalkyl group such as cyclopentyl or cyclohexyl. Alternatively, it is preferably a polycyclic cycloalkyl group such as norbornyl, tetracyclic decyl, tetracyclic dodecyl, or adamantyl. More preferably, it is a monocyclic cycloalkyl group with 5 to 6 carbon atoms. In the cycloalkyl or cycloalkenyl group formed by the two bonds of Ry1 to Ry3, for example, one of the methylene groups constituting the ring may be substituted with a heteroatom such as an oxygen atom, a carbonyl group, a -SO2- group, a -SO3- group, or a group containing a heteroatom, or a vinylidene group, or a combination thereof. Furthermore, one or more of the ethyl groups constituting the cycloalkane ring or cycloalkene ring in these cycloalkyl or cycloalkenyl groups may be substituted with vinylidene groups. The repeating unit represented by formula (B) is preferably, for example, Ry1 being methyl, ethyl, vinyl, allyl, or aryl, and Ry2 and Ry3 are bonded to form the cycloalkyl or cycloalkenyl group.

[0109] When each of the groups has a substituent, examples of substituents include: alkyl (1 to 4 carbon atoms), halogen atom, hydroxyl group, alkoxy group (1 to 4 carbon atoms), carboxyl group, and alkoxycarbonyl group (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-degradable (meth)acrylate ter ester repeating unit (Xb represents a hydrogen atom or methyl and L represents a -CO- group repeating unit), an acid-degradable hydroxystyrene ter alkyl ether repeating unit (Xb represents a hydrogen atom or methyl and L represents a phenyl repeating unit), or an acid-degradable styrene carboxylic acid ter ester repeating unit (Xb represents a hydrogen atom or methyl and L represents a -Rt-CO- group (Rt is an aromatic group) repeating unit).

[0111] The content of repeating units having acid-degradable groups containing unsaturated bonds is preferably 15 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, relative to all repeating units in resin (A). Furthermore, as an upper limit, it is preferably 80 mol% or less, more preferably 70 mol% or less, and especially preferably 60 mol% or less, relative to all repeating units in resin (A).

[0112] The following shows specific examples of repeating units having acid-decomposable groups containing unsaturated bonds, but the present invention is not limited thereto. Furthermore, in the formula, Xb and L1 represent any of the substituents and linking groups described above, Ar represents an aromatic group, R represents a hydrogen atom, alkyl, cycloalkyl, aryl, aralkyl, alkenyl, hydroxyl, alkoxy, acetoxy, cyano, nitro, amino, halogen atom, ester group (-OCOR''' or -COOR''': R'''' is an alkyl or fluorinated alkyl with 1 to 20 carbon atoms), or a carboxyl group, etc., R' represents a straight-chain or branched alkyl, monocyclic or polycyclic cycloalkyl, alkenyl, alkynyl, monocyclic or polycyclic aryl, Q represents a heteroatom such as an oxygen atom, a carbonyl group, a group containing a heteroatom such as -SO2- or -SO3-, or a vinylidene group, or a combination thereof, and l, n and m represent integers of 0 or more.

[0113] [Chemistry 17]

[0114] [Chemical 18]

[0115] [Chemistry 19]

[0116] [Chemistry 20]

[0117] (Repeating unit with polar group) Resin (A) may contain repeating units with polar groups. Examples of polar groups include hydroxyl, cyano, and carboxyl groups. The repeating unit with a polar group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. Furthermore, the repeating unit with a polar group is preferably without an acid-degradable group. The alicyclic hydrocarbon structure substituted with a polar group is preferably adamantyl or norbornyl.

[0118] The following are specific examples of monomers corresponding to repeating units having polar groups, but the present invention is not limited to these specific examples. In addition, the specific examples described below are methacrylate compounds, but may also be acrylate compounds.

[0119] [Chemistry 21]

[0120] Furthermore, as specific examples of repeating units having polar groups, the structural units disclosed in paragraphs 0415 to 0433 of the specification in U.S. Patent Application Publication No. 2016 / 0070167 may also be cited. The resin (A) may contain only one type of repeating unit having a polar group, or it may contain two or more types in combination. When the resin (A) contains repeating units having polar groups, the content of the repeating unit is preferably 0.1 mol% to 40 mol%, more preferably 1 mol% to 30 mol%, relative to all repeating units in the resin (A).

[0121] The resin (A) may also contain repeating units other than the repeating units. For example, the resin (A) may also contain at least one repeating unit selected from the group consisting of the following group A, and / or at least one repeating unit selected from the group consisting of the following group B. Group A: Groups containing repeating units of the following (20) to (29). (20) Repeating units with acid groups as described below (21) Repeating units with fluorine or iodine atoms as described below (22) Repeating units with lactone, sulcinolone, or carbonate groups as described below (23) Repeating units with photoacid-generating groups as described below (24) Repeating units represented by formula (V-1) or formula (V-2) as described below (25) Repeating units represented by formula (A) as described below (26) Repeating units represented by formula (B) as described below (27) Repeating units represented by formula (C) as described below (28) Repeating units represented by formula (D) as described below (29) Repeating units represented by formula (E) as described below Group B: A group consisting of repeating units comprising (30) to (32) as described below. (30) The repeating unit described below having at least one group selected from lactone, sulcinolone, carbonate, hydroxyl, cyano, and base-soluble groups. (31) The repeating unit described below having an alicyclic hydrocarbon structure and not exhibiting acid decomposition properties. (32) The repeating unit described below not having either a hydroxyl or a cyano group, represented by formula (III).

[0122] Resin (A) preferably has acid groups, and more preferably contains repeating units with acid groups as described later. Furthermore, the definition of acid groups will be explained later along with the preferred state of repeating units with acid groups. When resin (A) has acid groups, the interaction between resin (A) and the acid generated from compound (B) is more excellent. As a result, acid diffusion can be further suppressed, and the cross-sectional shape of the formed pattern can be further rectangularized.

[0123] When the resist composition is used as a photosensitive or radiosensitive linear resin composition for EUV, resin (A) preferably contains at least one repeating unit selected from the group consisting of said group A. Furthermore, when the resist composition is used as a photosensitive or radiosensitive linear resin composition for EUV, resin (A) preferably contains at least one of fluorine atoms and iodine atoms. When resin (A) contains both fluorine atoms and iodine atoms, resin (A) may have one repeating unit containing both fluorine atoms and iodine atoms, or resin (A) may contain both repeating units containing fluorine atoms and repeating units containing iodine atoms. Furthermore, when the resist composition is used as a photosensitive or radiosensitive linear resin composition for EUV, resin (A) also preferably contains a repeating unit having an aromatic group. When the resist composition is used as a photosensitive or radiosensitive linear resin composition for ArF, resin (A) preferably contains at least one repeating unit selected from the group consisting of said group B. Furthermore, when the resist composition is used as a photosensitive or radiosensitive linear resin composition for ArF, resin (A) preferably does not contain either fluorine atoms or silicon atoms. Additionally, when the resist composition is used as a photosensitive or radiosensitive linear resin composition for ArF, resin (A) preferably does not contain aromatic groups.

[0124] The resin (A) preferably has at least one group selected from the group consisting of lactone, carbonate, sulopentalide, and cyclic groups having a hydroxyl group. The lactone, carbonate, or sulopentalide groups will be described later. The cyclic group having a hydroxyl group is preferably an alicyclic group having a hydroxyl group; specific examples include groups illustrated in the repeating units having hydroxyl groups described later.

[0125] <Repetitive Units with Acid Groups> Resin (A) preferably contains repeating units with acid groups. The acid group is preferably an acid group with a pKa of 13 or less. As described above, the acid dissociation constant of the acid group is preferably 13 or less, more preferably 3 to 13, and even more preferably 5 to 10. When resin (A) has acid groups with a pKa of 13 or less, the content of the acid group in resin (A) is not particularly limited, and is generally 0.2 mmol / g to 6.0 mmol / g. Preferably, it is 0.8 mmol / g to 6.0 mmol / g, more preferably 1.2 mmol / g to 5.0 mmol / g, and even more preferably 1.6 mmol / g to 4.0 mmol / g. If the content of the acid group is within the aforementioned range, development proceeds well, and the resulting pattern shape and resolution are excellent. As an acid group, it is preferably a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group. Furthermore, one or more fluorine atoms in the hexafluoroisopropanol group (preferably one to two) may be substituted with groups other than fluorine atoms (alkoxycarbonyl groups, etc.). As an acid group, it is also preferably -C(CF3)(OH)-CF2- formed in this way. Additionally, one or more fluorine atoms may also be substituted with groups other than fluorine atoms to form a ring containing -C(CF3)(OH)-CF2-. The repeating unit having the acid group is preferably a repeating unit with a structure having a releasable group protected by a releasable group that has been removed by the action of an acid, and a repeating unit different from the repeating units having lactone, sulopentalide, or carbonate groups described later.

[0126] Repeating units with acid groups may also have fluorine or iodine atoms.

[0127] The following repeating units can be listed as repeating units having acid groups.

[0128] [Chemistry 22]

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

[0130] [Chemistry 23]

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

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

[0133] The following examples illustrate repeating units with acid groups. In the formula, a represents 1 or 2.

[0134] [Chemical 24]

[0135] [Chemical 25]

[0136] [Chemistry 26]

[0137] Furthermore, the repeating unit is preferably the repeating unit specifically described below. In the formula, R represents a hydrogen atom or a methyl group, and a represents 2 or 3.

[0138] [Chemical 27]

[0139] [Chemistry 28]

[0140] The content of repeating units having acid groups is preferably 10 mol% or more, more preferably 15 mol% or more, relative to all repeating units in resin (A). Furthermore, as an upper limit, it is preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less, relative to all repeating units in resin (A).

[0141] <Repeating units having fluorine, bromine, or iodine atoms> Resin (A) may also contain repeating units having fluorine, bromine, or iodine atoms, independent of the aforementioned <repeating units having acid-decomposing groups> and <repeating units having acid groups>. Furthermore, the <repeating units having fluorine, bromine, or iodine atoms> described herein are preferably different from other types of repeating units belonging to Group A, such as <repeating units having lactone, sulopentalide, or carbonate groups> and <repeating units having photoacid-generating groups> described later.

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

[0143] [Chemistry 29]

[0144] L5 represents a single bond or an ester group. R9 represents a hydrogen atom or an alkyl group that may have fluorine, bromine, or iodine atoms. R10 represents a hydrogen atom, an alkyl group that may have fluorine, bromine, or iodine atoms, a cycloalkyl group that may have fluorine, bromine, or iodine atoms, an aryl group that may have fluorine, bromine, or iodine atoms, or a combination thereof.

[0145] The following are examples of repeating units having fluorine or iodine atoms.

[0146] [Chemistry 30]

[0147] The content of repeating units having fluorine, bromine, or iodine atoms is preferably 0 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, relative to all repeating units in resin (A). Furthermore, as an upper limit, it is preferably 50 mol% or less, more preferably 45 mol% or less, and even more preferably 40 mol% or less, relative to all repeating units in resin (A). Moreover, as described above, the repeating units having fluorine, bromine, or iodine atoms do not include <repeating units having acid-decomposable groups> and <repeating units having acid groups>, therefore, the content of repeating units having fluorine, bromine, or iodine atoms also refers to the content of repeating units having fluorine, bromine, or iodine atoms other than <repeating units having acid-decomposable groups> and <repeating units having acid groups>.

[0148] Among the repeating units of resin (A), the total content of repeating units containing at least one of fluorine, bromine, and iodine atoms, relative to all repeating units of resin (A), is preferably 10 mol% or more, more preferably 20 mol% or more, further preferably 30 mol% or more, and particularly preferably 40 mol% or more. There is no particular upper limit; for example, it may be 100 mol% or less relative to all repeating units of resin (A). Furthermore, examples of repeating units containing at least one of fluorine, bromine, and iodine atoms include: repeating units having fluorine, bromine, or iodine atoms and having an acid-decomposing group; repeating units having fluorine, bromine, or iodine atoms and having an acid group; and repeating units having fluorine, bromine, or iodine atoms.

[0149] <A repeating unit having at least one group selected from lactone, sulopentalide, carbonate, hydroxyl, cyano, and base-soluble groups> Resin (A) may contain repeating units having at least one group selected from lactone, sulopentalide, carbonate, hydroxyl, cyano, and base-soluble groups. First, repeating units having at least one group selected from the group consisting of lactone, sulopentalide, and carbonate groups (hereinafter, also collectively referred to as "repeating units having lactone, sulopentalide, or carbonate groups") will be described. Repeating units having lactone, sulopentalide, or carbonate groups are preferably free of acid groups such as hydroxyl and hexafluoropropanol groups.

[0150] As a lactone group or sulfonolactone group, it is acceptable as long as it has a lactone structure or sulfonolactone structure. The lactone structure or sulfonolactone structure is preferably a 5-membered ring lactone structure to a 7-membered ring lactone structure or a 5-membered ring sulfonolactone structure to a 7-membered ring sulfonolactone structure. More preferably, it is a lactone structure formed by ring condensation of a 5-membered ring lactone structure to a 7-membered ring lactone structure in the form of a bicyclic or spirocyclic structure, or a sulfonolactone structure formed by ring condensation of a 5-membered ring sulfonolactone structure to a 7-membered ring sulfonolactone structure in the form of a bicyclic or spirocyclic structure. The resin (A) preferably has a repeating unit having a lactone group or sulfonolactone group formed by removing one or more hydrogen atoms from the ring member atoms of a lactone structure represented by any one of the following formulas (LC1-1) to (LC1-21), or a sulfonolactone structure represented by any one of the following formulas (SL1-1) to (SL1-3). In addition, lactone or sulfonyl groups can be directly bonded to the main chain. For example, the ring-membered atoms of lactone or sulfonyl groups can form the main chain of resin (A).

[0151] [Chemistry 31]

[0152] The lactone or sulopentalide structure may have a substituent (Rb2). Preferred substituents (Rb2) include: alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 4 to 7 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkoxycarbonyl groups having 1 to 8 carbon atoms, carboxyl groups, halogen atoms, cyano groups, and acid-degradable groups. n2 represents an integer from 0 to 4. When n2 is 2 or more, the multiple Rb2 groups may be different, and the multiple Rb2 groups may bond together to form a ring.

[0153] The repeating unit is a base having a lactone structure represented by any of the formulas (LC1-1) to (LC1-21) or a sulfonolactone structure represented by any of the formulas (SL1-1) to (SL1-3), for example, the repeating unit represented by the following formula (AI) can be listed.

[0154] [Chemistry 32]

[0155] In formula (AI), Rb0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferred substituents for the alkyl group of Rb0 include hydroxyl and halogen atoms. Examples of halogen atoms for Rb0 include fluorine, chlorine, bromine, and iodine atoms. Rb0 is preferably a hydrogen atom or a methyl group. Ab represents a single bond, an alkyl group, a divalent linker having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group composed of these. Preferably, it is a single bond or a linker represented by -Ab1-CO2-. Ab1 is a straight-chain or branched alkyl group, or a monocyclic or polycyclic cycloalkyl group, preferably methylene, ethyl, cyclohexyl, adamantyl, or norbornyl. V represents a group formed by removing a hydrogen atom from the ring member atom of the lactone structure represented by any of the formulas (LC1-1) to (LC1-21), or a group formed by removing a hydrogen atom from the ring member atom of the sulfonyl lactone structure represented by any of the formulas (SL1-1) to (SL1-3).

[0156] When an optical isomer is present in a repeating unit having a lactone group or a sulcinolone group, any optical isomer may be used. Alternatively, a single optical isomer may be used alone, or multiple optical isomers may be used in combination. When primarily using one optical isomer, its optical purity (ee) is preferably 90 or higher, and more preferably 95 or higher.

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

[0158] [Chemistry 33]

[0159] In formula (A-1), RA 1 represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably methyl). n represents an integer greater than or equal to 0. RA 2 represents a substituent. When n is 2 or more, multiple RA 2s may be identical or different. A represents a single bond or a divalent linker. As the divalent linker, preferably an alkyl group, a divalent linker having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group formed by combining these. Z represents a group that forms a monocyclic or polycyclic ring together with the group represented by -O-CO-O- in the formula.

[0160] The following examples illustrate repeating units having a lactone group, a sulcinolone group, or a carbonate group.

[0161] [Chemistry 34]

[0162] [Chemistry 35]

[0163] [Chemistry 36]

[0164] Next, repeating units having hydroxyl or cyano groups will be described. Resin (A) may contain repeating units having hydroxyl or cyano groups. This improves substrate adhesion and developer affinity. The repeating units having hydroxyl or cyano groups are preferably repeating units having an alicyclic hydrocarbon structure substituted with hydroxyl or cyano groups. The repeating units having hydroxyl or cyano groups are preferably not acid-degradable groups. As repeating units having hydroxyl or cyano groups, those described in paragraphs

[0081] to

[0084] of Japanese Patent Application Publication No. 2014-98921 can be cited.

[0165] Next, the repeating unit having an alkali-soluble group will be described. The resin (A) may contain repeating units having an alkali-soluble group. Examples of alkali-soluble groups include: carboxyl groups, sulfonamide groups, sulfonylimidin groups, disulfonylimidin groups, and aliphatic alcohol groups substituted with electron-withdrawing groups at the α-position (e.g., hexafluoroisopropanol groups), with carboxyl groups being preferred. By including repeating units having alkali-soluble groups in the resin (A), the resolution in contact hole applications is increased. Examples of repeating units having alkali-soluble groups include those described in paragraphs

[0085] and

[0086] of Japanese Patent Application Publication No. 2014-98921.

[0166] The content of repeating units having at least one group selected from lactone, sulcinolone, carbonate, hydroxyl, cyano, and alkali-soluble groups is preferably 1 mol% or more, more preferably 10 mol% or more, relative to all repeating units in resin (A). Furthermore, as an upper limit, it is preferably 85 mol% or less, more preferably 80 mol% or less, further preferably 70 mol% or less, and particularly preferably 60 mol% or less, relative to all repeating units in resin (A).

[0167] <Repetitive Unit with Photoacid Generating Group> The resin (A) may also contain repeating units other than those described above, which have a group that generates acid by irradiation with photochemical rays or radiation (hereinafter also referred to as "photoacid generating group"). In this case, the repeating unit with photoacid generating group can be considered equivalent to the photoacid generating agent (B). As such repeating units, the repeating unit represented by the following formula (4) can be listed as an example.

[0168] [Chemistry 37]

[0169] R41 represents a hydrogen atom or a methyl group. L41 represents a single bond or a divalent linkage. L42 represents a divalent linkage. R40 represents a structural site that decomposes upon exposure to photochemical rays or radiation and produces an acid in the side chain. The following examples illustrate repeating units with photoacid-producing groups.

[0170] [Chemistry 38]

[0171] In addition, as the repeating unit represented by formula (4), for example, the repeating units described in paragraphs

[0094] to

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

[0094] of International Publication No. 2018 / 193954 can be listed.

[0172] The content of repeating units having photoacid-generating groups is preferably 1 mol% or more, more preferably 5 mol% or more, relative to all repeating units in resin (A). Furthermore, as an upper limit, it is preferably 40 mol% or less, more preferably 35 mol% or less, and even more preferably 30 mol% or less, relative to all repeating units in resin (A).

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

[0174] [Chemistry 39]

[0175] In the formula, R6 and R7 independently represent a hydrogen atom, hydroxyl group, alkyl group, alkoxy group, acetoxy group, cyano group, nitro group, amino group, halogen atom, ester group (-OCOR or -COOR: R is an alkyl or fluorinated alkyl group with 1 to 6 carbon atoms), or carboxyl group. As an alkyl group, it is preferred to be a straight-chain, branched, or cyclic alkyl group with 1 to 10 carbon atoms. n3 represents an integer from 0 to 6. n4 represents an integer from 0 to 4. X4 is a methylene group, an oxygen atom, or a sulfur atom. The repeating units represented by formula (V-1) or formula (V-2) are illustrated below. For example, the repeating units described in paragraph

[0100] of International Publication No. 2018 / 193954 can be cited as examples of repeating units represented by formula (V-1) or formula (V-2).

[0176] <Repeating Units for Reducing Main Chain Mobility> From the viewpoint of suppressing excessive diffusion of acid or pattern collapse during development, resin (A) preferably has a high glass transition temperature (Tg). Tg is preferably greater than 90°C, more preferably greater than 100°C, further preferably greater than 110°C, and especially preferably greater than 125°C. Furthermore, excessively high Tg leads to a decrease in the dissolution rate in the developer; therefore, Tg is preferably below 400°C, more preferably below 350°C. Furthermore, in this specification, the glass transition temperature (Tg) of the polymer such as resin (A) (hereinafter referred to as "Tg of the repeating unit") is calculated by the following method. First, the Tg of the homopolymer containing only each repeating unit contained in the polymer is calculated separately using the Bicerano method. Next, the mass percentage (%) of each repeating unit relative to all repeating units in the polymer is calculated. Next, the Tg for each mass ratio was calculated using the Fox formula (described in Materials Letters 62 (2008) 3152, etc.), and these were summed to form the Tg (°C) of the polymer. The Bicerano method is described in Prediction of polymer properties, Marcel Dekker Inc, New York (1993). Furthermore, the Tg calculated using the Bicerano method can be performed using the polymer property estimation software MDL Polymer (MDL Information Systems, Inc.).

[0177] In order to increase the Tg of resin (A) (preferably setting the Tg to be greater than 90°C), it is preferable to reduce the mobility of the main chain of resin (A). Methods for reducing the mobility of the main chain of resin (A) include the following methods (a) to (e): (a) Introducing a bulky substituent into the main chain; (b) Introducing multiple substituents into the main chain; (c) Introducing substituents that induce interactions between resins (A) near the main chain; (d) Forming the main chain with a cyclic structure; (e) Linkage between the cyclic structure and the main chain. Furthermore, resin (A) preferably has repeating units with a Tg of 130°C or higher in homopolymers. Furthermore, there is no particular limitation on the type of repeating units with a Tg of 130°C or higher in homopolymers, as long as the repeating unit has a Tg of 130°C or higher in homopolymers calculated by the Bicerano method. Furthermore, based on the types of functional groups in the repeating units represented by equations (A) to (E) described later, the repeating units corresponding to the Tg of the homopolymer show a value of 130°C or higher.

[0178] (Repeating unit represented by formula (A)) As an example of a specific method of achieving (a), a method of introducing the repeating unit represented by formula (A) into resin (A) can be cited.

[0179] [Chemistry 40]

[0180] In formula (A), RA represents a group containing a polycyclic structure. RX represents a hydrogen atom, a methyl group, or an ethyl group. A group containing a polycyclic structure is a group containing multiple ring structures, which may or may not be condensed. Specific examples of repeating units represented by formula (A) can be found in paragraphs

[0107] to

[0119] of International Publication No. 2018 / 193954.

[0181] (Repeating unit represented by formula (B)) As an example of a specific method of achieving (b), a method of introducing the repeating unit represented by formula (B) into resin (A) can be cited.

[0182] [Chemistry 41]

[0183] In formula (B), Rb1 to Rb4 independently represent hydrogen atoms or organic groups, and at least two of Rb1 to Rb4 represent organic groups. Furthermore, if at least one of the organic groups is a group with a ring structure directly linked to the main chain of the repeating unit, there are no particular restrictions on the types of other organic groups. Furthermore, if none of the organic groups is a group with a ring structure directly linked to the main chain of the repeating unit, at least two of the organic groups are substituents with three or more structural atoms other than hydrogen atoms. Specific examples of the repeating units represented by formula (B) can be cited from paragraphs

[0113] to

[0115] of International Publication No. 2018 / 193954.

[0184] (Repeating unit represented by formula (C)) As an example of a specific method of achieving (c), a method of introducing the repeating unit represented by formula (C) into resin (A) can be cited.

[0185] [Chemistry 42]

[0186] In formula (C), Rc1 to Rc4 independently represent hydrogen atoms or organic groups, and at least one of Rc1 to Rc4 is a group in which hydrogen atoms with hydrogen bonding at least 3 atoms originating from a carbon atom in the main chain. Preferably, the hydrogen atoms with hydrogen bonding at least 2 atoms (closer to the main chain) are based on the interaction between the main chains of the induced resin (A). Specific examples of the repeating units represented by formula (C) can be cited from paragraphs

[0119] to

[0121] of International Publication No. 2018 / 193954.

[0187] (Repeating unit represented by formula (D)) As an example of a specific method of achieving (d), a method of introducing the repeating unit represented by formula (D) into resin (A) can be cited.

[0188] [Chemistry 43]

[0189] In formula (D), "cyclic" means that the base forms the main chain in a cyclic structure. There is no particular limitation on the number of atoms constituting the ring. As specific examples of repeating units represented by formula (D), those described in paragraphs

[0126] to

[0127] of International Publication No. 2018 / 193954 can be cited.

[0190] (Repeating unit represented by formula (E)) As an example of a specific method of achieving (e), a method of introducing the repeating unit represented by formula (E) into resin (A) can be cited.

[0191] [Chemistry 44]

[0192] In formula (E), Re independently represents either a hydrogen atom or an organogroup. Examples of organogroups include alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups, which may have substituents. "Cyclic" refers to a cyclic group containing carbon atoms of the main chain. There is no particular limitation on the number of atoms contained in a cyclic group. Specific examples of repeating units represented by formula (E) can be found in paragraphs

[0131] to

[0133] of International Publication No. 2018 / 193954.

[0193] <Repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposition> The resin (A) may contain repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposition. This reduces the dissolution of low molecular weight components from the resist film into the immersion solution during immersion exposure. Examples of such repeating units include repeating units derived from 1-adamantyl (meth)acrylate, disadamantyl (meth)acrylate, tricyclodecane (meth)acrylate, or cyclohexyl (meth)acrylate.

[0194] <Repeating unit represented by formula (III) that does not have either hydroxyl or cyano groups> Resin (A) may contain repeating units represented by formula (III) that do not have either hydroxyl or cyano groups.

[0195] [Chemistry 45]

[0196] In formula (III), R5 represents a hydrocarbon group having at least one cyclic structure and not having either a hydroxyl or a cyano group. Ra represents a hydrogen atom, an alkyl group, or a -CH2-O-Ra2 group. In the formula, Ra2 represents a hydrogen atom, an alkyl group, or a acetyl group. As repeating units represented by formula (III) that do not have either a hydroxyl or a cyano group, those described in paragraphs

[0087] to

[0094] of Japanese Patent Application Publication No. 2014-98921 can be cited.

[0197] <Other Repeating Units> Furthermore, the resin (A) may have repeating units other than the aforementioned repeating units. For example, the resin (A) may contain repeating units selected from the group consisting of repeating units having an oxathiane ring group, repeating units having an oxazolone ring group, repeating units having a dioxane ring group, and repeating units having a hydantoin ring group. Such repeating units are illustrated below.

[0198] [Chemistry 46]

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

[0200] As resin (A), (especially in the case where the composition is used as a photosensitive radioactive or radiosensitive linear resin composition for ArF) it is preferable that all repeating units are composed of repeating units derived from compounds having ethylene unsaturated bonds. It is also particularly preferable that all repeating units are composed of (meth)acrylate repeating units. In this case, any of the following can be used: all repeating units are methacrylate repeating units, all repeating units are acrylate repeating units, or all repeating units are composed of both methacrylate and acrylate repeating units. It is preferable that the acrylate repeating units account for 50 moles or less of all repeating units.

[0201] Resin (A) can be synthesized by conventional methods (e.g., free radical polymerization). Using GPC and based on polystyrene conversion, the weight-average molecular weight of resin (A) is preferably 30,000 or less, more preferably 1,000 to 30,000, more preferably 3,000 to 30,000, and even more preferably 5,000 to 15,000. The dispersity (molecular weight distribution) of resin (A) is typically 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 dispersity, the better the resolution and resist shape, resulting in smoother sidewalls and better roughness of the resist pattern.

[0202] In the resist composition, the content of resin (A) is preferably 40.0% to 99.9% by mass, more preferably 60.0% to 90.0% by mass, relative to all solid components of the composition. One type of resin (A) may be used, or multiple types may be used in combination.

[0203] [Solvent (F)] The resist composition preferably includes a solvent (preferably an organic solvent). The solvent preferably includes at least one of (M1) and (M2), wherein (M1) is a propylene glycol monoalkyl ether carboxylic acid ester, and (M2) is at least one selected from the group consisting of propylene glycol monoalkyl ethers, lactates, acetates, alkoxypropionates, chain ketones, cyclic ketones, lactones, and alkyl carbonates. Furthermore, the solvent may further include components other than (M1) and (M2).

[0204] Details of the ingredients (M1) and (M2) are set out in paragraphs

[0218] to

[0226] of International Publication No. 2020 / 004306, which are incorporated herein by reference.

[0205] In the case where the solvent further includes components other than component (M1) and component (M2), the content of components other than component (M1) and component (M2) is preferably 5% to 30% by mass relative to the total amount of solvent.

[0206] The solvent content in the resist composition is preferably set to a solid component concentration of 0.5% to 30% by mass, more preferably to a solid component concentration of 1% to 20% by mass. This can further improve the coatability of the resist composition. Furthermore, the term "solid component" refers to all components other than the solvent.

[0207] 〔A compound (B) that produces acid by exposure to photochemical rays or radiation (photoacid generator)〕 The resist composition contains a compound (B) that produces acid by exposure to photochemical rays or radiation (photoacid generator).

[0208] Compound (B) may be in the form of a low molecular weight compound or in the form incorporated into a portion of a polymer (e.g., the resin (A)). Alternatively, both the low molecular weight compound form and the form incorporated into a portion of a polymer (e.g., the resin (A)) may be used together. 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 limitation on the lower limit, but it is preferably 100 or more. When compound (B) is in the form incorporated into a portion of a polymer, it may be incorporated into a portion of resin (A) or into a resin different from resin (A). Compound (B) is preferably a low molecular weight compound.

[0209] As compound (B), examples include compounds represented by "M+ X-" (onium salts), preferably compounds that generate organic acids by exposure. Examples of said organic acids include: sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, and camphor sulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, and aralkyl carboxylic acids, etc.), carbonyl sulfonyliminic acids, bis(alkyl sulfonyliminic acids), and tri(alkyl sulfonyliminic acids).

[0210] The molecular weight of the acid produced 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> In compounds represented by "M+ X-", M+ represents an organic cation. The structure of the organic cation is not particularly limited. Furthermore, the valence of the organic cation may be monovalent or divalent or higher. Preferably, the organic cation is 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] [Chemistry 47]

[0213] In general formula (ZaI), R201, R202, and R203 each independently represent an organic group. In general formula (ZaII), R204 and R205 each independently represent an organic group. General formulas (ZaI) and (ZaII) will be described in detail below, but it is preferred that at least one of R201, R202, and R203 in general formula (ZaI) is an aryl group, or at least one of R204 and R205 in general formula (ZaII) is an aryl group. The aryl group may have substituents, preferably halogen atoms (preferably fluorine or iodine atoms) or organic groups. Furthermore, it is also preferred that at least one of R201, R202, and R203 in general formula (ZaI) has an acid-decomposable group, or at least one of R204 and R205 in general formula (ZaII) has an acid-decomposable group. Regarding the acid-decomposable group, it is the same as the acid-decomposable group in resin (A). Preferably, at least one of R201, R202, and R203 in the general formula (ZaI) has an acid-decomposable group, and at least one of R201, R202, and R203 is an aryl group substituted with an organic group containing the acid-decomposable group. Preferably, at least one of R204 and R205 in the general formula (ZaII) has an acid-decomposable group, and at least one of R204 and R205 is an aryl group substituted with an organic group containing the acid-decomposable group.

[0214] The cation (ZaI) will be described. The number of carbon atoms in the organic groups of R201, R202, and R203 is generally 1 to 30, preferably 1 to 20. In addition, two of R201 to R203 can be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amino group, or a carbonyl group. Examples of groups formed by the bond between the two of R201 to R203 include alkyl groups (e.g., butyl and pentyl) and -CH2-CH2-O-CH2-CH2-.

[0215] As preferred examples of organic cations in formula (ZaI), the following examples include cation (ZaI-1), cation (ZaI-2), organic cation (ZaI-3b) represented by formula (ZaI-3b), and organic cation (ZaI-4b) represented by formula (ZaI-4b).

[0216] First, the cation (ZaI-1) will be described. The cation (ZaI-1) is an aryl strontium cation in which at least one of R201 to R203 of the formula (ZaI) is aryl. The aryl strontium cation may be composed entirely of aryl groups from R201 to R203, or may be composed of a portion of aryl groups from R201 to R203, with the remainder being alkyl or cycloalkyl. In addition, one of R201 to R203 is aryl, and the remaining two of R201 to R203 may be bonded to form a ring structure, which may contain an oxygen atom, a sulfur atom, an ester group, an amino group, or a carbonyl group. As a group formed by the bond of two of R201 to R203, for example, one or more methylene groups may be substituted with an oxygen atom, a sulfur atom, an ester group, an amino group, and / or a carbonyl group, such as alkyl groups (e.g., butyl, pentylene, and -CH2-CH2-O-CH2-CH2-). Examples of aryl strontium cations include: triaryl strontium cations, diarylalkyl strontium cations, aryldialkyl strontium cations, diarylcycloalkyl strontium cations, and aryldicycloalkyl strontium cations.

[0217] The aryl group contained in the aryl strontium cation is preferably phenyl or naphthyl, and more preferably phenyl. The aryl group may be an aryl group containing a heterocyclic structure having an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of heterocyclic structures include: pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, and benzothiophene residues. When the aryl strontium cation has two or more aryl groups, the two or more aryl groups may be the same or different. The alkyl or cycloalkyl group that the aryl strontium cation is required to have is preferably a straight-chain 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 methyl, ethyl, propyl, n-butyl, dibutyl, tributyl, cyclopropyl, cyclobutyl, or cyclohexyl.

[0218] The aryl, alkyl, and cycloalkyl groups of R201 to R203 may preferably have substituents that are independently alkyl (e.g., 1 to 15 carbon atoms), cycloalkyl (e.g., 3 to 15 carbon atoms), aryl (e.g., 6 to 14 carbon atoms), alkoxy (e.g., 1 to 15 carbon atoms), cycloalkylalkoxy (e.g., 1 to 15 carbon atoms), halogen atoms (e.g., fluorine and iodine), hydroxyl, carboxyl, ester, sulfinyl, sulfonyl, alkylthio, and phenylthio. Where possible, the substituents may further have substituents, and it is also preferred that the alkyl group has a halogen atom as a substituent to become a trifluoromethyl or other halogenated alkyl group. Furthermore, the substituents are preferably formed by any combination to create an acid-degradable group. Moreover, an acid-degradable group refers to a group that decomposes under the action of an acid to produce a polar group, preferably a structure in which the polar group is released by a release group protected by an acid. The polar group and the release group are as described above.

[0219] Next, the cation (ZaI-2) will be described. The cation (ZaI-2) is a cation in which R201 to R203 in the formula (ZaI) each independently represents an organic group that does not have an aromatic ring. The aromatic ring also includes an aromatic ring containing a heteroatom. The organic group that does not have an aromatic ring, which is R201 to R203, usually has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. R201 to R203 are preferably alkyl, cycloalkyl, allyl, or vinyl group, more preferably straight-chain or branched 2-oxoalkyl, 2-oxocycloalkyl, or alkoxycarbonylmethyl, and even more preferably straight-chain or branched 2-oxoalkyl.

[0220] The alkyl and cycloalkyl groups of R201 to R203 may include, for example, straight-chain alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl). R201 to R203 may be further substituted with a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. In addition, the substituents of R201 to R203 are preferably acid-degradable groups formed independently by any combination of substituents.

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

[0222] [Chemistry 48]

[0223] In formula (ZaI-3b), R1c to R5c independently represent hydrogen atoms, alkyl, cycloalkyl, aryl, alkoxy, aryloxy, alkoxycarbonyl, alkylcarbonyloxy, cycloalkylcarbonyloxy, halogen atoms, hydroxyl, nitro, alkylthio, or arylthio. R6c and R7c independently represent hydrogen atoms, alkyl (e.g., tertiary butyl), cycloalkyl, halogen atoms, cyano, or aryl. Rx and Ry independently represent alkyl, cycloalkyl, 2-oxoalkyl, 2-oxocycloalkyl, alkoxycarbonylalkyl, allyl, or vinyl. Furthermore, the substituents of R1c to R7c, and Rx and Ry, are preferably formed independently by any combination of substituents to create acid-degradable groups.

[0224] Any two or more of R1c to R5c, R5c and R6c, R6c and R7c, R5c and Rx, and Rx and Ry can be bonded to each other to form a ring, which can also independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of such rings 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 rings include 3-membered to 10-membered rings, preferably 4-membered to 8-membered rings, and more preferably 5-membered or 6-membered rings.

[0225] The group formed by the bonding of any two or more of R1c to R5c, R6c and R7c, and Rx and Ry can be alkyl groups such as butylyl and pentylyl. The methylene group in the alkyl group may be substituted with a heteroatom such as an oxygen atom. The group formed by the bonding of R5c and R6c, and R5c and Rx, is preferably a single bond or an alkyl group. The alkyl group can be alkyl groups such as methylene and ethylyl.

[0226] R1c~R5c, R6c, R7c, Rx, Ry, and any two or more of R1c~R5c, R5c and R6c, R6c and R7c, R5c and Rx, and Rx and Ry may have substituents.

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

[0228] [Chemistry 49]

[0229] In formula (ZaI-4b), l represents an integer from 0 to 2. r represents an integer from 0 to 8. R13 represents a hydrogen atom, a halogen atom (e.g., fluorine and iodine atoms), a hydroxyl group, an alkyl group, a haloalkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a group containing a cycloalkyl group (which may be the cycloalkyl group itself or a group containing a cycloalkyl group). These groups may have substituents. R14 represents a hydroxyl group, a halogen atom (e.g., fluorine and iodine atoms), an alkyl group, a haloalkyl 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 the cycloalkyl group itself or a group containing a cycloalkyl group). These groups may have substituents. When multiple R14s are present, each of the above groups, such as a hydroxyl group, represents an independent group. R15 represents an alkyl group, a cycloalkyl group, or a naphthyl group. Two R15s may be bonded together to form a ring. When two R15 atoms are bonded together to form a ring, the ring skeleton may contain heteroatoms such as oxygen or nitrogen atoms. In one state, it is preferable that the two R15 atoms are alkyl groups and are bonded together to form a ring structure. Furthermore, the alkyl group, the cycloalkyl group, the naphthyl group, and the ring formed by the two R15 atoms may have substituents.

[0230] In formula (ZaI-4b), the alkyl groups of R13, R14, and R15 can be straight-chain or branched. The number of carbon atoms in the alkyl group is preferably 1 to 10. The alkyl group is more preferably methyl, ethyl, n-butyl, or tributyl, etc. Furthermore, each substituent in R13 to R15, as well as Rx and Ry, is preferably formed independently by any combination of substituents to create an acid-degradable group.

[0231] Next, formula (ZaII) will be described. In formula (ZaII), R204 and R205 each independently represent an organic group, preferably an aryl, alkyl, or cycloalkyl group. The aryl group of R204 and R205 is preferably phenyl or naphthyl, and more preferably phenyl. The aryl group of R204 and R205 may also be an aryl group containing a heterocycle having an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of heterocyclic aryl groups include: pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. The alkyl and cycloalkyl groups of R204 and R205 are preferably straight-chain alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, or pentyl), or cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, or norbornyl).

[0232] The aryl, alkyl, and cycloalkyl groups of R204 and R205 may each independently have substituents. Examples of substituents that may be present in the aryl, alkyl, and cycloalkyl groups of R204 and R205 include: alkyl groups (e.g., 1 to 15 carbon atoms), cycloalkyl groups (e.g., 3 to 15 carbon atoms), aryl groups (e.g., 6 to 15 carbon atoms), alkoxy groups (e.g., 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups. Furthermore, the substituents in R204 and R205 are preferably acid-degradable groups formed independently by any combination of substituents.

[0233] The following are specific examples of organic cations represented by M+, but the present invention is not limited to these.

[0234] [Chemical 50]

[0235] [Chemistry 51]

[0236] [Chemical 52]

[0237] [Chemical 53]

[0238] <Organic Anion> In compounds represented by "M+ X-", X- represents an organic anion. There are no particular limitations on the organic anion, and examples include monovalent or divalent organic anions. Preferably, the organic anion is an anion with a significantly low ability to induce nucleophilic reactions, and more preferably, a non-nucleophilic anion.

[0239] As non-nucleophilic anions, examples include: sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, and camphor sulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, and aralkyl carboxylate anions, etc.), sulfenimine anions, bis(alkylsulfenyl)imine anions, and tri(alkylsulfenyl)methyl anions.

[0240] The aliphatic portion of the aliphatic sulfonate anion and the aliphatic carboxylate anion may be a straight-chain or branched alkyl group, or a cycloalkyl group, preferably a straight-chain 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 substituents other than fluorine atoms. It may also be a perfluoroalkyl group).

[0241] The aryl group in the aromatic sulfonate anion and the aromatic carboxylate anion is preferably an aryl group with 6 to 14 carbon atoms, for example: phenyl, tolyl and naphthyl.

[0242] The alkyl, cycloalkyl, and aryl groups listed above may have substituents. There are no particular limitations on the substituents, but specifically, the following may be included: nitro, halogen atoms such as fluorine or chlorine atoms, carboxyl, hydroxyl, amino, cyano, alkoxy (preferably 1 to 15 carbon atoms), alkyl (preferably 1 to 10 carbon atoms), cycloalkyl (preferably 3 to 15 carbon atoms), aryl (preferably 6 to 14 carbon atoms), alkoxycarbonyl (preferably 2 to 7 carbon atoms), acetyl (preferably 2 to 12 carbon atoms), alkoxycarbonyloxy (preferably 2 to 7 carbon atoms), alkylthio (preferably 1 to 15 carbon atoms), alkylsulfonyl (preferably 1 to 15 carbon atoms), alkyliminosulfonyl (preferably 1 to 15 carbon atoms), and aryloxysulfonyl (preferably 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 aralkyl groups having 7 to 14 carbon atoms include benzyl, phenethyl, naphthylmethyl, naphthylethyl, and naphthylbutyl.

[0244] As a sulfonylimidimine anion, saccharin anion can be cited as an example.

[0245] The alkyl group in the bis(alkylsulfonyl)imine anion and the tri(alkylsulfonyl)methyl anion is preferably an alkyl group having 1 to 5 carbon atoms. Examples of substituents for these alkyl groups include: halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, and cycloalkylaryloxysulfonyl groups; fluorine atoms or alkyl groups substituted with fluorine atoms are preferred. Furthermore, the alkyl groups in the bis(alkylsulfonyl)imine anion can bond to each other to form a ring structure. This increases the acid strength.

[0246] Other nonnucleophilic anions include, for example, phosphorus fluoride (e.g., PF6-), boron fluoride (e.g., BF4-), and antimony fluoride (e.g., SbF6-).

[0247] As a non-nucleophilic anion, it is preferably an aliphatic sulfonate anion with at least α-fluorine atom substitution, an aromatic sulfonate anion with fluorine atom substitution or a fluorine-containing alkyl group substitution, an alkyl-fluorine-substituted bis(alkylsulfonyl)imidion anion, or an alkyl-fluorine-substituted tri(alkylsulfonyl)methylation anion. More preferably, it is a perfluoroaliphatic sulfonate anion (preferably having 4 to 8 carbon atoms), or a benzenesulfonate anion with a fluorine atom, and even more preferably, a nonafluorobutanesulfonate anion, a perfluorooctanesulfonate anion, a pentafluorobenzenesulfonate anion, or a 3,5-bis(trifluoromethyl)benzenesulfonate anion.

[0248] As a preferred example of a non-nucleophilic anion, anion represented by the following formula (AN4) can be listed.

[0249] [Chemical 54]

[0250] In formula (AN4), R1 to R3 independently represent organic groups or hydrogen atoms. L represents a divalent linker.

[0251] In formula (AN4), L represents a divalent linker. When there are multiple Ls, the Ls may be the same or different. Examples of divalent linkers include: -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -S-, -SO-, -SO2-, alkylene groups (preferably with 1 to 6 carbons), cycloalkylene groups (preferably with 3 to 15 carbons), alkenylene groups (preferably with 2 to 6 carbons), and divalent linkers formed by combining multiple of these. Among them, the divalent linker is preferably -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -SO2-, -O-CO-O-extrinyl-, -COO-extrinyl-, or -CONH-extrinyl-, more preferably -O-CO-O-, -O-CO-O-extrinyl-, -COO-, -CONH-, -SO2-, or -COO-extrinyl-.

[0252] L is preferably represented by the basis shown in the following formula (AN4-2): *a-(CR2a 2)XQ-(CR2b 2)Y-*b (AN4-2)

[0253] In formula (AN4-2), *a represents the bond position with R3 in formula (AN4). *b represents the bond position with -C(R1)(R2)- in formula (AN4). X and Y independently represent integers from 0 to 10, preferably integers from 0 to 3. R2a and R2b independently represent hydrogen atoms or substituents. When multiple R2a and R2b exist, the multiple R2a and R2b can be the same or different. Among them, when Y is 1 or more, R2b in CR2b 2 directly bonded with -C(R1)(R2)- in formula (AN4) is not a fluorine atom. Q represents *AO-CO-O-*B, *A-CO-*B, *A-CO-O-*B, *AO-CO-*B, *AO-*B, *AS-*B, or *A-SO2-*B. In formula (AN4-2), where X+Y is 1 or more and either R2a or R2b in formula (AN4-2) is a hydrogen atom, Q represents *AO-CO-O-*B, *A-CO-*B, *AO-CO-*B, *AO-*B, *AS-*B, or *A-SO2-*B. *A represents the bond position on the R3 side in formula (AN4), and *B represents the bond position on the -SO3- side in formula (AN4).

[0254] In formula (AN4), R1 to R3 independently represent organic groups. The organic group is not limited as long as it has one or more carbon atoms; it can be a straight-chain group (e.g., a straight-chain alkyl group), a branched group (e.g., a branched alkyl group such as tert-butyl), or a cyclic group. The organic group may or may not have substituents. The organic group may or may not have heteroatoms (oxygen atom, sulfur atom, and / or nitrogen atom, etc.). Examples of non-electron-withdrawing substituents include: hydrocarbon groups, hydroxyl groups, oxyhydrocarbon groups, oxycarbonyl hydrocarbon groups, amino groups, hydrocarbon-substituted amino groups, and hydrocarbon-substituted amide groups. Furthermore, the substituents used as non-electron-extracting groups are preferably -R', -OH, -OR', -OCOR', -NH2, -NR'2, -NHR', or -NHCOR', each independently. R' is a monovalent hydrocarbon group.

[0255] Examples of monovalent hydrocarbon groups represented by R' include: alkyl groups such as methyl, ethyl, propyl, and butyl; alkenyl groups such as vinyl, propynyl, 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 cyclopropenyl, cyclobutenyl, cyclopentenyl, and norbornyl; aryl groups such as phenyl, tolyl, xylyl, mesitylelel, naphthyl, methylnaphthyl, anthracenel, and methylanthrayl; and aralkyl groups such as benzyl, phenethyl, phenylpropyl, naphthylmethyl, and anthracenemethyl. Preferably, R1 and R2 are independently hydrocarbon groups (preferably cycloalkyl) or hydrogen atoms.

[0256] Wherein, R3 is preferably an organogroup with a cyclic structure. The cyclic structure can be monocyclic or polycyclic, and may also have substituents. The ring in the organogroup containing the cyclic structure is preferably directly bonded to L in formula (AN4). The organogroup with the cyclic structure may, for example, have heteroatoms (oxygen atom, sulfur atom, and / or nitrogen atom, etc.), or may not have heteroatoms. The heteroatoms may be substituted with one or more carbon atoms forming the cyclic structure. The organogroup with the cyclic structure is preferably, for example, a cyclic hydrocarbon group, a lactone cyclic group, or a sulfonyl lactone cyclic group. Wherein, the organogroup with the cyclic structure is preferably a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a monocyclic or polycyclic cycloalkyl group. These groups may have substituents. The cycloalkyl group may be monocyclic (cyclohexyl, etc.) or polycyclic (adamantyl, etc.), and the number of carbon atoms is preferably 5 to 12. The lactone cyclic group and sulfonyl lactone cyclic group are preferably formed by removing a hydrogen atom from any of the structures represented by formulas (LC1-1) to (LC1-21) and formulas (SL1-1) to (SL1-3) that constitute the lactone structure or sulfonyl lactone structure.

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

[0258] [Chemical 55] In equation (AN1)

[0259] , o represents an integer from 1 to 3. p represents an integer from 0 to 10. q represents an integer from 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 an organic group without a fluorine atom. The organic group (preferably an alkyl group) preferably has 1 to 10 carbon atoms, more preferably 1 to 4. Furthermore, as an organic group substituted with at least one fluorine atom (preferably an alkyl group), it 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 even more 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 multiple R4 and R5 are present, R4 and R5 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 substituents. Hydrogen atoms are preferred as R4 and R5. Specific examples and preferred states of alkyl groups substituted with at least one fluorine atom are the same as those of Xf in formula (AN1).

[0262] L represents a divalent linker. When multiple Ls exist, they may be the same or different. Examples of divalent linkers include: -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -S-, -SO-, -SO2-, alkylene groups (preferably with 1 to 6 carbons), cycloalkylene groups (preferably with 3 to 15 carbons), alkenylene groups (preferably with 2 to 6 carbons), and divalent linkers formed by combining multiple of these. Among them, the divalent linker is preferably -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -SO2-, -O-CO-O-extrinyl-, -COO-extrinyl-, or -CONH-extrinyl-, more preferably -O-CO-O-, -O-CO-O-extrinyl-, -COO-, -CONH-, -SO2-, or -COO-extrinyl-.

[0263] W represents an organic group containing a cyclic structure. Preferably, it is a cyclic organic group. Examples of cyclic organic groups include alicyclic groups, aryl groups, and heterocyclic groups. Alicyclic groups can be monocyclic or polycyclic. Examples of monocyclic alicyclic groups include cyclopentyl, cyclohexyl, and cyclooctyl monocyclic cycloalkyl groups. Examples of polycyclic alicyclic groups include norbornyl, tricyclic decyl, tetracyclic decyl, tetracyclic dodecyl, and adamantyl polycyclic cycloalkyl groups. Preferably, it is alicyclic groups with a large volume structure having 7 or more carbon atoms, such as norbornyl, tricyclic decyl, tetracyclic decyl, tetracyclic dodecyl, and adamantyl.

[0264] The aryl group can be monocyclic or polycyclic. Examples of the aryl group include phenyl, naphthyl, phenanthryl, and anthracene. The heterocyclic group can be monocyclic or polycyclic. In the case of a polycyclic heterocyclic group, the diffusion of acid can be further suppressed. In addition, the heterocyclic group may or may not be aromatic. Examples of aromatic heterocycles include furan ring, thiophene ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, and pyridine ring. Examples of non-aromatic heterocycles include tetrahydropyran ring, lactone ring, sulfonyl lactone ring, and decahydroisoquinoline ring. The heterocycle in the heterocyclic group is preferably a furan ring, thiophene ring, pyridine ring, or decahydroisoquinoline ring.

[0265] The cyclic organic group may have substituents. Examples of such substituents include: alkyl groups (which may be either linear or branched, preferably with 1 to 12 carbon atoms), cycloalkyl groups (which may be monocyclic, polycyclic, or spirocyclic, preferably with 3 to 20 carbon atoms), aryl groups (preferably with 6 to 14 carbon atoms), hydroxyl groups, alkoxy groups, ester groups, amide groups, carbamate groups, urea groups, thioether groups, sulfonamide groups, and sulfonate groups. Furthermore, the carbon atom constituting the cyclic organic group (the carbon atom that contributes to ring formation) may be a carbonyl carbon. Additionally, two or more substituents may bond together to form a ring. For example, the case of two alkoxy groups, or a hydroxyl group bonded to an alkoxy group, forming a ring with a cyclic acetal structure, can be cited. This ring may have substituents. Examples of substituents include: alkyl (1-4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1-4 carbon atoms), carboxyl groups, and alkoxycarbonyl groups (2-6 carbon atoms).

[0266] The anion represented by formula (AN1) is preferably 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)qW, or SO3-CF2-CH(CF3)-OCO-(L)q'-W. Here, L, q, and W are the same as in formula (AN1). q' represents an integer from 0 to 10.

[0267] The anion represented by formula (AN1) is preferably in the following states (AN2) and (AN3). State (AN2): In formula (AN1), o represents 2, p represents 0, and the two Xfs bonded to the carbon atom directly bonded to -SO3- (hereinafter, the carbon atom is also referred to as "carbon atom Z1") independently represent hydrogen atoms or organic groups without fluorine atoms. The two Xfs bonded to the carbon atom adjacent to the carbon atom (hereinafter, the carbon atom is also referred to as "carbon atom Z2") independently represent hydrogen atoms or organic groups. The preferred states of q, L, and W are the same as those described above. The two Xfs bonded to carbon atom Z1 are preferably hydrogen atoms. It is more preferably that at least one of the two Xfs bonded to carbon atom Z2 is a fluorine atom or an organic group with fluorine atoms, more preferably both are fluorine atoms or organic groups with fluorine atoms, and even more preferably both are fluorine-substituted alkyl groups.

[0268] State (AN3): In formula (AN1), one of the two Xfs independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom, and the other independently represents a hydrogen atom or an organogroup without a fluorine atom. The preferred states of o, p, q, R4, R5, L, and W are the same as those described above.

[0269] As a non-nucleophilic anion, it can be a benzenesulfonate anion, preferably a benzenesulfonate anion substituted with branched alkyl or cycloalkyl groups.

[0270] As a non-nucleophilic anion, it is also preferred to be an aromatic sulfonate anion represented by the following formula (AN5).

[0271] [Chemistry 56]

[0272] In formula (AN5), Ar represents an aryl group (phenyl, etc.), and may further have a sulfonate anion and substituents other than -(DB) group. Examples of substituents that may be further included are fluorine atoms and hydroxyl groups.

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

[0274] D represents a single bond or a divalent linker. Examples of divalent linkers include: ether groups, thioether groups, carbonyl groups, ternary groups, ternary groups, sulfonate groups, ester groups, and groups containing two or more of these.

[0275] B represents a hydrocarbon group.

[0276] B is preferably an aliphatic hydrocarbon structure. B is more preferably isopropyl, cyclohexyl, or aryl (tricyclohexylphenyl, etc.) that may further have substituents. In addition, B may further have substituents represented by "-(L)qW". L, q, and W have the same meaning as L, q, and W in the stated formula (An1), and the specific examples and preferred ranges are also the same.

[0277] As a non-nucleophilic anion, a disulfonamide anion is preferred. The disulfonamide anion is, for example, an anion represented by N-(SO2-Rq)2. Here, Rq represents an alkyl group that may have substituents, preferably a fluoroalkyl group, and more preferably a perfluoroalkyl group. Two Rq groups may bond together to form a ring. The group formed by the bonding of two Rq groups is preferably a substituent-containing alkyl group, more preferably a fluoroalkyl group, and even more preferably a perfluoroalkyl group. The alkyl group preferably has 2 to 4 carbon atoms.

[0278] In addition, as non-nucleophilic anions, anions represented by the following formulas (d1-1) to (d1-4) can also be listed.

[0279] [Chemical 57]

[0280] [Transformation 58]

[0281] In formula (d1-1), R51 represents a hydrocarbon group (e.g., aryl group such as phenyl group) that may have substituents (e.g., hydroxyl group).

[0282] In formula (d1-2), Z2c represents a hydrocarbon group with 1 to 30 carbon atoms that may have substituents (wherein the carbon atom adjacent to S is not substituted with a fluorine atom). The hydrocarbon group in Z2c may be linear, branched, or have a cyclic structure. In addition, the carbon atom in the hydrocarbon group (preferably a carbon atom that is a ring member when the hydrocarbon group has a cyclic structure) may be a carbonyl carbon (-CO-). As the hydrocarbon group, for example, a group containing norbornyl that may have substituents can be listed. The carbon atom forming the norbornyl may be a carbonyl carbon. In addition, "Z2c-SO3-" in formula (d1-2) is preferably different from the anion represented by formula (AN4), formula (AN1), or formula (AN5). For example, Z2c is preferably not an aryl group. In addition, for example, the atoms at the α and β positions relative to -SO3- in Z2c are preferably atoms other than carbon atoms with a fluorine atom as a substituent. For example, in Z2c, the atoms at the α-position and / or β-position relative to -SO3- are preferably ring members in a cyclic group.

[0283] In formula (d1-3), R52 represents an organic group (preferably a hydrocarbon group with fluorine atoms), Y3 represents a straight-chain, branched, or cyclic alkyl, aryl, or carbonyl group, and Rf represents a hydrocarbon group.

[0284] In formula (d1-4), R53 to R54 represent organic groups (preferably hydrocarbon groups with fluorine atoms). R53 to R54 can also bond with each other to form a ring.

[0285] Organic anions can be used alone or in combination with two or more.

[0286] The resist composition is preferably composed of two or more compounds (B), or the compound (B) is at least one selected from the group consisting of the following compounds (I) and the following compounds (II).

[0287] <Compound (I) and Compound (II)> Compound (B) is preferably selected from at least one of the group consisting of the following compounds (I) and the following compounds (II).

[0288] (Compound (I)) Compound (I) is a compound having one or more structural sites X and one or more structural sites Y, and producing an acid upon irradiation by photochemical rays or radiation, wherein the acid comprises a first acidic site derived from structural site X and a second acidic site derived from structural site Y. Structural site X: a structural site comprising an anionic site A1- and a cation site M1+, and forming a first acidic site represented by HA1 upon irradiation by photochemical rays or radiation. Structural site Y: a structural site comprising an anionic site A2- and a cation site M2+, and forming a second acidic site represented by HA2 upon irradiation by photochemical rays or radiation. The cation sites M1+ and M2+ preferably represent organic cations independently, and specific examples and preferred ranges are the same as those for the organic cation represented by M+. In addition, compound (I) satisfies the following condition I.

[0289] Condition I: In the compound (I), the compound PI formed by replacing the cation M1+ in the structural site X and the cation M2+ in the structural site Y with H+ has an acid dissociation constant a1 derived from the acidic site represented by HA1, which is formed by replacing the cation M1+ in the structural site X with H+, and an acid dissociation constant a2 derived from the acidic site represented by HA2, which is formed by replacing the cation M2+ in the structural site Y with H+, and the acid dissociation constant a2 is greater than the acid dissociation constant a1.

[0290] Hereinafter, condition I will be explained in more detail. When compound (I) is, for example, a compound that produces an acid having a first acidic site derived from the structural site X and a second acidic site derived from the structural site Y, compound PI is equivalent to "a compound having HA1 and HA2". In more detail, the acid dissociation constants a1 and a2 of such compound PI are as follows: when the acid dissociation constants of compound PI are determined, the pKa of compound PI when it is "a compound having A1- and HA2" is the acid dissociation constant a1, and the pKa of "a compound having A1- and HA2" when it is "a compound having A1- and A2-" is the acid dissociation constant a2.

[0291] Furthermore, when compound (I) is, for example, a compound that produces an acid having two first acidic sites originating from the structural site X and one second acidic site originating from the structural site Y, compound PI is equivalent to "a compound having two HA1 and one HA2". When the acid dissociation constant of such compound PI is determined, the acid dissociation constant when compound PI is "a compound having one A1, one HA1, and one HA2", and the acid dissociation constant when "a compound having one A1, one HA1, and one HA2" is "a compound having two A1 and one HA2", are equivalent to the acid dissociation constant a1. Additionally, the acid dissociation constant when "a compound having two A1 and one HA2" is "a compound having two A1 and A2", is equivalent to the acid dissociation constant a2. That is, in the case of compound PI, when there are multiple acid dissociation constants derived from the acidic site represented by HA1, which is formed by replacing the cation site M1+ in the structural site X with H+, the value of acid dissociation constant a2 is greater than the largest value among the multiple acid dissociation constants a1. Furthermore, when the acid dissociation constant of compound PI is defined as "a compound having one A1-, one HA1, and one HA2", and the acid dissociation constant of "a compound having one A1-, one HA1, and one HA2" is defined as "a compound having two A1- and one HA2", the relationship between aa and ab satisfies aa < ab.

[0292] The acid dissociation constants a1 and a2 are determined by the method for determining the acid dissociation constant. The compound PI corresponds to the acid produced when compound (I) is irradiated with photochemical rays or radiation. When compound (I) has two or more structural sites X, the structural sites X may be the same or different. In addition, the two or more A1- and the two or more M1+ may be the same or different. In addition, in compound (I), the A1- and A2-, as well as the M1+ and M2+ may be the same or different, but the A1- and A2- are preferably different.

[0293] In the compound PI, the absolute value of the difference between the acid dissociation constant a1 (which is the maximum value when there are multiple acid dissociation constants a1) and the acid dissociation constant a2 is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 1.0 or more. Furthermore, there is no particular limitation on the upper limit of the absolute value of the difference between the acid dissociation constant a1 (which is the maximum value when there are multiple acid dissociation constants a1) and the acid dissociation constant a2, for example, it is 16 or less.

[0294] In the compound PI, the acid dissociation constant a2 is, for example, 20 or less, preferably 15 or less. Furthermore, as a lower limit value of the acid dissociation constant a2, it is preferably -4.0 or more.

[0295] Furthermore, in the compound PI, the acid dissociation constant a1 is preferably 2.0 or less, more preferably 0 or less. Moreover, as a lower limit value of the acid dissociation constant a1, it is preferably -20.0 or more.

[0296] Anionic sites A1- and A2- are structural sites containing negatively charged atoms or groups of atoms. For example, structural sites selected from the group consisting of formulas (AA-1) to (AA-3) and (BB-1) to (BB-6) shown below can be included. As anionic site A1-, it is preferable to form an acidic site with a small acid dissociation constant, and more preferably any one of formulas (AA-1) to (AA-3), and even more preferably any one of formulas (AA-1) and (AA-3). In addition, as anionic site A2-, it is preferable to form an acidic site with a larger acid dissociation constant than anionic site A1-, and more preferably any one of formulas (BB-1) to (BB-6), and even more preferably any one of formulas (BB-1) and (BB-4). Furthermore, in the following formulas (AA-1) to (AA-3) and (BB-1) to (BB-6), * indicates the bonding position. In formula (AA-2), RA independently represents a monovalent organic group.

[0297] [Chemical 59]

[0298] [Transformation 60]

[0299] There are no particular limitations on the specific structure of compound (I), for example, compounds represented by formulas (Ia-1) to (Ia-5) described later can be listed.

[0300] - The compound represented by formula (Ia-1)- Hereinafter, the compound represented by formula (Ia-1) will be described first.

[0301] M11 + A11 --L1-A12 - M12 + (Ia-1)

[0302] The compound represented by formula (Ia-1) produces an acid represented by HA11-L1-A12H by irradiation with photochemical rays or radiation.

[0303] In formula (Ia-1), M11+ and M12+ independently represent organic cations. A11- and A12- independently represent monovalent anionic functional groups. L1 represents a divalent linker. M11+ and M12+ may be the same or different. A11- and A12- may be the same or different, preferably different from each other. In the compound PIa (HA11-L1-A12H) formed by replacing the cations represented by M11+ and M12+ with H+ in formula (Ia-1), the acid dissociation constant a2 derived from the acidic site represented by A12H is greater than the acid dissociation constant a1 derived from the acidic site represented by HA11. Furthermore, the preferred values ​​of acid dissociation constant a1 and acid dissociation constant a2 are as described above. In addition, compound PIa is the same as the acid produced from the compound represented by formula (Ia-1) by irradiation with photochemical rays or radiation. In addition, at least one of M11+, M12+, A11-, A12-, and L1 may have an acid-degradable group as a substituent.

[0304] In formula (Ia-1), the organic cations represented by M11+ and M12+ are the same as those represented by M+.

[0305] The monovalent anionic functional group represented by A11- refers to a monovalent group containing the anionic site A1-. Furthermore, the monovalent anionic functional group represented by A12- refers to a monovalent group containing the anionic site A2-. Preferably, the monovalent anionic functional groups represented by A11- and A12- are monovalent anionic functional groups containing the anionic sites of any one of formulas (AA-1) to (AA-3) and (BB-1) to (BB-6), and more preferably are monovalent anionic functional groups selected from the group consisting of formulas (AX-1) to (AX-3) and (BX-1) to (BX-7). Among the monovalent anionic functional groups represented by A11-, it is more preferably a monovalent anionic functional group represented by any one of formulas (AX-1) to (AX-3). Furthermore, as a monovalent anionic functional group represented by A12-, it is preferably a monovalent anionic functional group represented by any one of formulas (BX-1) to (BX-7), and more preferably a monovalent anionic functional group represented by any one of formulas (BX-1) to (BX-6).

[0306] [Chemical 61]

[0307] In formulas (AX-1) to (AX-3), RA1 and RA2 independently represent monovalent organic groups. * indicates the bond position.

[0308] As a monovalent organic group represented by RA1, examples include: cyano, trifluoromethyl, and methanesulfonyl.

[0309] The monovalent organic group represented by RA2 is preferably a straight-chain, branched, or cyclic alkyl group or an aryl group. The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 6. The alkyl group may have substituents. The substituents are preferably fluorine atoms or cyano groups, more preferably fluorine atoms. When the alkyl group has a fluorine atom as a substituent, it may be a perfluoroalkyl group.

[0310] The aryl group is preferably phenyl or naphthyl, more preferably phenyl. The aryl group may have substituents. The substituents are preferably fluorine atoms, iodine atoms, perfluoroalkyl groups (e.g., preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), or cyano groups, more preferably fluorine atoms, iodine atoms, or perfluoroalkyl groups.

[0311] In formulas (BX-1) to (BX-4) and (BX-6), RB represents a monovalent organic group. * indicates a bond position. The monovalent organic group represented by RB is preferably a straight-chain, branched, or cyclic alkyl group, or an aryl group. The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 6. The alkyl group may have substituents. Substituents are not particularly limited, but fluorine atoms or cyano groups are preferred, and fluorine atoms are more preferred. When the alkyl group has a fluorine atom as a substituent, it may be a perfluoroalkyl group. Furthermore, when the carbon atom at the bonding position in the alkyl group (for example, in formulas (BX-1) and (BX-4), it corresponds to the carbon atom in the alkyl group directly bonded to the -CO- group explicitly stated in the formula; in formulas (BX-2) and (BX-3), it corresponds to the carbon atom in the alkyl group directly bonded to the -SO2- group explicitly stated in the formula; and in formula (BX-6), it corresponds to the carbon atom in the alkyl group directly bonded to the N- group explicitly stated in the formula) has a substituent, it is preferably a substituent other than a fluorine atom or a cyano group. Additionally, the carbon atom in the alkyl group may be substituted with a carbonyl carbon.

[0312] The aryl group is preferably phenyl or naphthyl, more preferably phenyl. The aryl group may have substituents. Substituents are preferably fluorine atoms, iodine atoms, perfluoroalkyl groups (e.g., preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), cyano groups, alkyl groups (e.g., preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), alkoxy groups (e.g., preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), or alkoxycarbonyl groups (e.g., preferably having 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms), and more preferably fluorine atoms, iodine atoms, perfluoroalkyl groups, alkyl groups, alkoxy groups, or alkoxycarbonyl groups.

[0313] In formula (Ia-1), the divalent linker represented by L1 is not particularly limited and may include: -CO-, -NR-, -O-, -S-, -SO-, -SO2-, alkyl groups (preferably with 1 to 6 carbon atoms, which may be straight-chain or branched), cycloalkyl groups (preferably with 3 to 15 carbon atoms), alkenyl groups (preferably with 2 to 6 carbon atoms), and divalent aliphatic heterocyclic groups (preferably having at least one N atom, O atom, S atom, or Se atom within the ring structure). The rings can be 5- to 10-membered rings, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings. Other options include divalent aromatic heterocyclic groups (preferably 5- to 10-membered rings having at least one N, O, S, or Se atom within the ring structure, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings), divalent aromatic hydrocarbon cyclic groups (preferably 6- to 10-membered rings, and even more preferably 6-membered rings), and divalent linking groups formed by combining multiple of these. R can include hydrogen atoms or monovalent organic groups. Monovalent organic groups are not particularly limited, but are preferably alkyl groups (preferably having 1 to 6 carbon atoms). Furthermore, the alkyl groups, cycloalkyl groups, alkenyl groups, divalent aliphatic heterocyclic groups, divalent aromatic heterocyclic groups, and divalent aromatic hydrocarbon cyclic groups may have substituents. Examples of substituents include halogen atoms (preferably fluorine atoms).

[0314] In this context, the binary linking base represented by L1 is preferably the binary linking base represented by formula (L1).

[0315] [Chemical 62]

[0316] In formula (L1), L111 represents a single bond or a divalent linker. The divalent linker represented by L111 is not particularly limited, and examples include: -CO-, -NH-, -O-, -SO-, -SO2-, alkyl groups with substituents (preferably 1 to 6 carbon atoms, and may be either straight-chain or branched), cycloalkyl groups with substituents (preferably 3 to 15 carbon atoms), aryl groups with substituents (preferably 6 to 10 carbon atoms), and divalent linkers formed by combining multiple of these. Substituents are not particularly limited, and examples include halogen atoms. p represents an integer from 0 to 3, preferably an integer from 1 to 3. v represents an integer of 0 or 1. Xf1 independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 4. Furthermore, as an alkyl group substituted with at least one fluorine atom, a perfluoroalkyl group is preferred. Xf2 independently represents a hydrogen atom, an alkyl group that may have a fluorine atom as a substituent, or a fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 4. Among them, Xf2 is preferably a fluorine atom, or an alkyl group substituted with at least one fluorine atom, more preferably a fluorine atom, or a perfluoroalkyl group. Among them, Xf1 and Xf2 are preferably either fluorine atoms or perfluoroalkyl groups having 1 to 4 carbon atoms, more preferably fluorine atoms or CF3. In particular, it is even more preferable that both Xf1 and Xf2 are fluorine atoms. * indicates the bonding position. When L1 in formula (Ia-1) represents the divalent linker represented by formula (L1), it is preferable that the bonding bond (*) on the L111 side of formula (L1) is bonded to A12 in formula (Ia-1).

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

[0318] [Chemistry 63]

[0319] In formula (Ia-2), A21a- and A21b- each independently represent a monovalent anionic functional group. Here, the monovalent anionic functional group represented by A21a- and A21b- refers to a monovalent group containing the anionic site A1-. There is no particular limitation on the monovalent anionic functional group represented by A21a- and A21b-, for example, monovalent anionic functional groups selected from the group consisting of formulas (AX-1) to (AX-3) can be listed. A22- represents a divalent anionic functional group. Here, the divalent anionic functional group represented by A22- refers to a divalent group containing the anionic site A2-. As a divalent anionic functional group represented by A22-, for example, the divalent anionic functional groups represented by formulas (BX-8) to (BX-11) shown below can be listed.

[0320] [Chemical 64]

[0321] M21a+, M21b+, and M22+ each independently represent an organic cation. The organic cations represented by M21a+, M21b+, and M22+ have the same meaning as M1+, and the preferred state is also the same. L21 and L22 each independently represent a divalent organic group.

[0322] Furthermore, in the compound PIa-2 formed by replacing the organic cations represented by M21a+, M21b+, and M22+ with H+ in formula (Ia-2), the acid dissociation constant a2 derived from the acidic site represented by A22H is greater than the acid dissociation constant a1-1 derived from A21aH and the acid dissociation constant a1-2 derived from the acidic site represented by A21bH. Moreover, the acid dissociation constants a1-1 and a1-2 are equivalent to the acid dissociation constant a1. Furthermore, A21a- and A21b- may be the same or different from each other. Additionally, M21a+, M21b+, and M22+ may be the same or different from each other. Furthermore, at least one of M21a+, M21b+, M22+, A21a-, A21b-, L21, and L22 may have an acid-decomposing group as a substituent.

[0323] In formula (Ia-3), A31a- and A32- independently represent monovalent anionic functional groups. Furthermore, the definition of the monovalent anionic functional group represented by A31a- is the same as that of A21a- and A21b- in formula (Ia-2), and the preferred form is also the same. The monovalent anionic functional group represented by A32- refers to a monovalent group containing the anionic site A2-. There is no particular limitation on the monovalent anionic functional group represented by A32-; for example, monovalent anionic functional groups selected from the group consisting of formulas (BX-1) to (BX-7) can be listed. A31b- represents a divalent anionic functional group. Here, the divalent anionic functional group represented by A31b- refers to a divalent group containing the anionic site A1-. As a divalent anionic functional group represented by A31b-, for example, the divalent anionic functional group represented by the following formula (AX-4) can be listed.

[0324] [Chemical 65]

[0325] M31a+, M31b+, and M32+ each independently represent a monovalent organic cation. The organic cations represented by M31a+, M31b+, and M32+ have the same meaning as M1+, and the preferred state is also the same. L31 and L32 each independently represent a divalent organic group.

[0326] Furthermore, in the compound PIa-3 formed by replacing the organic cations represented by M31a+, M31b+, and M32+ with H+ in formula (Ia-3), the acid dissociation constant a2 originating from the acidic site represented by A32H is greater than the acid dissociation constant a1-3 originating from the acidic site represented by A31aH and the acid dissociation constant a1-4 originating from the acidic site represented by A31bH. Moreover, the acid dissociation constants a1-3 and a1-4 are equivalent to the acid dissociation constant a1. Furthermore, A31a- and A32- may be the same or different from each other. Additionally, M31a+, M31b+, and M32+ may be the same or different from each other. In addition, at least one of M31a+, M31b+, M32+, A31a-, A32-, L31, and L32 may have an acid-degradable group as a substituent.

[0327] In formula (Ia-4), A41a-, A41b-, and A42- each independently represent a monovalent anionic functional group. Furthermore, the definitions of the monovalent anionic functional groups represented by A41a- and A41b- are the same as those for A21a- and A21b- in formula (Ia-2). Additionally, the definition of the monovalent anionic functional group represented by A42- is the same as that for A32- in formula (Ia-3), and the preferred state is also the same. M41a+, M41b+, and M42+ each independently represent an organic cation. L41 represents a trivalent organic group.

[0328] Furthermore, in formula (Ia-4), in compound PIA-4 formed by replacing the organic cations represented by M41a+, M41b+, and M42+ with H+, the acid dissociation constant a2 originating from the acidic site represented by A42H is greater than the acid dissociation constants a1-5 originating from the acidic site represented by A41aH and a1-6 originating from the acidic site represented by A41bH. Moreover, acid dissociation constants a1-5 and a1-6 are equivalent to the acid dissociation constant a1. Furthermore, A41a-, A41b-, and A42- may be the same or different from each other. Additionally, M41a+, M41b+, and M42+ may be the same or different from each other. In addition, at least one of M41a+, M41b+, M42+, A41a-, A41b-, A42-, and L41 may have an acid-degradable group as a substituent.

[0329] The divalent organogroups represented by L21 and L22 in formula (Ia-2) and L31 and L32 in formula (Ia-3) are not particularly limited, and examples include: -CO-, -NR-, -O-, -S-, -SO-, -SO2-, alkyl groups (preferably with 1 to 6 carbon atoms, which can be linear or branched), cycloalkyl groups (preferably with 3 to 15 carbon atoms), alkenyl groups (preferably with 2 to 6 carbon atoms), and divalent aliphatic heterocyclic groups (preferably having at least one nitrogen atom in the ring structure). The following are examples of 5- to 10-membered rings, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings, having at least one N, O, S, or Se atom within the ring structure; divalent aromatic heterocyclic groups (preferably 5- to 10-membered rings, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings); divalent aromatic hydrocarbon cyclic groups (preferably 6- to 10-membered rings, and even more preferably 6-membered rings); and divalent organogroups formed by combining multiple of these. R can include hydrogen atoms or monovalent organogroups. Monovalent organogroups are not particularly limited, but are preferably alkyl groups (preferably having 1 to 6 carbon atoms). Furthermore, the alkylene groups, cycloalkylene groups, alkenyl groups, divalent aliphatic heterocyclic groups, divalent aromatic heterocyclic groups, and divalent aromatic hydrocarbon cyclic groups may have substituents. Substituents include, for example, halogen atoms (preferably fluorine atoms).

[0330] The divalent organic groups represented by L21 and L22 in formula (Ia-2) and L31 and L32 in formula (Ia-3) are preferably, for example, the divalent organic groups represented by the following formula (L2).

[0331] [Chemistry 66]

[0332] In formula (L2), q represents an integer from 1 to 3. * indicates a bond position. Xf independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 4. In addition, as an alkyl group substituted with at least one fluorine atom, it 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. In particular, it is even more preferable that both Xf are fluorine atoms.

[0333] LA represents a single bond or a divalent linkage. There are no particular limitations on the divalent linkage represented by LA; examples include: -CO-, -O-, -SO-, -SO2-, alkyl groups (preferably with 1 to 6 carbon atoms; can be straight-chain or branched), cycloalkyl groups (preferably with 3 to 15 carbon atoms), divalent aromatic hydrocarbon cycloalloys (preferably 6-membered to 10-membered rings, and more preferably 6-membered rings), and divalent linkages formed by combining multiple of these. Furthermore, the alkyl groups, cycloalkyl groups, and divalent aromatic hydrocarbon cycloalloys may have substituents. Examples of substituents include halogen atoms (preferably fluorine atoms).

[0334] Examples of divalent organic groups 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-*, and *-Ph-OCO-CF2-*. Furthermore, *Ph* refers to an extensophenyl group that may have substituents, preferably 1,4-extensophenyl. Substituents are not particularly limited, but are preferably alkyl (e.g., preferably with 1 to 10 carbon atoms, more preferably with 1 to 6 carbon atoms), alkoxy (e.g., preferably with 1 to 10 carbon atoms, more preferably with 1 to 6 carbon atoms), or alkoxycarbonyl (e.g., preferably with 2 to 10 carbon atoms, more preferably with 2 to 6 carbon atoms). When L21 and L22 in formula (Ia-2) represent the divalent organogroup represented by formula (L2), it is preferable that the bonding bond (*) on the LA side of formula (L2) is bonded to A21a- and A21b- in formula (Ia-2). Furthermore, when L31 and L32 in formula (Ia-3) represent the divalent organogroup represented by formula (L2), it is preferable that the bonding bond (*) on the LA side of formula (L2) is bonded to A31a- and A32- in formula (Ia-3).

[0335] - The compound represented by formula (Ia-5)- Next, formula (Ia-5) will be explained.

[0336] [Chemical 67]

[0337] In formula (Ia-5), A51a-, A51b-, and A51c- each independently represent a monovalent anionic functional group. Here, the monovalent anionic functional group represented by A51a-, A51b-, and A51c- refers to a monovalent group containing the anionic site A1-. There is no particular limitation on the monovalent anionic functional groups represented by A51a-, A51b-, and A51c-, for example, monovalent anionic functional groups selected from the group consisting of formulas (AX-1) to (AX-3) can be listed. A52a- and A52b- represent divalent anionic functional groups. Here, the divalent anionic functional groups represented by A52a- and A52b- refer to divalent groups containing the anionic site A2-. As divalent anionic functional groups represented by A52a- and A52b-, examples include divalent anionic functional groups selected from the group consisting of formulas (BX-8) to (BX-11).

[0338] M51a+, M51b+, M51c+, M52a+, and M52b+ each independently represent an organic cation. The organic cations represented by M51a+, M51b+, M51c+, M52a+, and M52b+ have the same meaning as M1+, and the preferred state is also the same. L51 and L53 each independently represent a divalent organic group. The divalent organic groups represented by L51 and L53 have the same meaning as L21 and L22 in formula (Ia-2), and the preferred state is also the same. L52 represents a trivalent organic group. The trivalent organic group represented by L52 has the same meaning as L41 in formula (Ia-4), and the preferred state is also the same.

[0339] Furthermore, in the compound PIa-5 formed by replacing the organic cations represented by M51a+, M51b+, M51c+, M52a+, and M52b+ with H+ in formula (Ia-5), the acid dissociation constants a2-1 and a2-2 derived from the acidic site represented by A52aH are greater than the acid dissociation constants a1-1, a1-2, and a1-3 derived from the acidic site represented by A51cH. Moreover, acid dissociation constants a1-1 to a1-3 correspond to the acid dissociation constant a1, and acid dissociation constants a2-1 and a2-2 correspond to the acid dissociation constant a2. Furthermore, A51a-, A51b-, and A51c- may be the same as or different from each other. Additionally, A52a- and A52b- may be the same as or different from each other. Furthermore, M51a+, M51b+, M51c+, M52a+, and M52b+ may be the same as or different from each other. Additionally, at least one of M51b+, M51c+, M52a+, M52b+, A51a-, A51b-, A51c-, L51, L52, and L53 may have an acid-decomposing group as a substituent.

[0340] (Compound (II)) Compound (II) is a compound having two or more of the structural sites X and one or more of the structural sites Z, and producing an acid by irradiation with photochemical rays or radiation, wherein the acid comprises two or more first acidic sites derived from the structural sites X and the structural sites Z. Structural site Z: a ​​site capable of neutralizing the nonionic nature of the acid.

[0341] In compound (II), the definition of structural site X, and the definitions of A1- and M1+ are the same as those in compound (I), and the preferred state is also the same.

[0342] In the compound (II), the preferred range of the acid dissociation constant a1 of the acidic site represented by HA1, formed by replacing the cation M1+ in the structural site X with H+, in the compound PII is the same as that of the compound PI. Furthermore, if the compound (II) is, for example, a compound having two acids derived from the first acidic site of the structural site X and the acid of the structural site Z, then the compound PII is equivalent to "a compound having two HA1s". When the acid dissociation constant of the compound PII is determined, the acid dissociation constant of the compound PII when it is "a compound having one Al- and one HA1", and the acid dissociation constant of "a compound having one Al- and one HA1" when it is "a compound having two Al-", are equivalent to the acid dissociation constant a1.

[0343] The acid dissociation constant a1 is determined by the method for determining the acid dissociation constant. The compound PII corresponds to the acid produced when compound (II) is irradiated with photochemical rays or radiation. Furthermore, the two or more structural sites X may be the same or different. In addition, the two or more Al- and the two or more M1+ may be the same or different.

[0344] There are no particular limitations on the nonionicity of the acid in structural site Z, but it is preferable to include a site containing a functional group that can interact electrostatically with a proton or an electron. Examples of functional groups that can interact electrostatically with a proton or an electron include functional groups with macrocyclic structures such as cyclic polyethers or functional groups containing nitrogen atoms with non-covalent electron pairs that do not contribute to π-conjugation. A nitrogen atom with non-covalent electron pairs that do not contribute to π-conjugation is, for example, a nitrogen atom with a partial structure shown in the following formula.

[0345] [Chemical 68]

[0346] Examples of partial structures having a functional group or electron that can interact electrostatically with a proton include: crown ether structure, azacrown ether structure, primary amine structure to tertiary amine structure, pyridine structure, imidazole structure, and pyrazine structure, with primary amine structure to tertiary amine structure being preferred.

[0347] There are no particular limitations on the compound (II), for example, compounds represented by the following formula (IIa-1) and the following formula (IIa-2) can be listed.

[0348] [Transformation 69]

[0349] In formula (IIa-1), A61a- and A61b- have the same meaning as A11- in formula (Ia-1), and the preferred state is also the same. Additionally, M61a+ and M61b+ have the same meaning as M11+ in formula (Ia-1), and the preferred state is also the same. In formula (IIa-1), L61 and L62 have the same meaning as L1 in formula (Ia-1), and the preferred state is also the same.

[0350] In formula (IIa-1), R2X represents a monovalent organogroup. The monovalent organogroup represented by R2X is not particularly limited, and examples include: -CH2- may be substituted by one or more combinations of alkyl groups (preferably with 1 to 10 carbon atoms, and may be straight-chain or branched), cycloalkyl groups (preferably with 3 to 15 carbon atoms), or alkenyl groups (preferably with 2 to 6 carbon atoms) selected from the group consisting of -CO-, -NH-, -O-, -S-, -SO-, and -SO2-. Furthermore, the alkyl, cycloalkyl, and alkenyl groups may have substituents. Substituents are not particularly limited, and examples include halogen atoms (preferably fluorine atoms).

[0351] Furthermore, in the compound PIIa-1 formed by replacing the organic cations represented by M61a+ and M61b+ with H+ in formula (IIa-1), the acid dissociation constants a1-7 derived from the acidic site represented by A61aH and a1-8 derived from the acidic site represented by A61bH are equivalent to the acid dissociation constant a1. Moreover, in the compound PIIa-1 formed by replacing the cation sites M61a+ and M61b+ in the structural site X with H+ in formula (IIa-1), it is equivalent to HA61a-L61-N(R2X)-L62-A61bH. Additionally, compound PIIa-1 is the same acid produced from the compound represented by formula (IIa-1) by irradiation with photochemical rays or radiation. In addition, at least one of M61a+, M61b+, A61a-, A61b-, L61, L62, and R2X may have an acid-degradable group as a substituent.

[0352] In formula (IIa-2), A71a-, A71b-, and A71c- have the same meaning as A11- in formula (Ia-1), and the preferred state is also the same. Additionally, M71a+, M71b+, and M71c+ have the same meaning as M11+ in formula (Ia-1), and the preferred state is also the same. In formula (IIa-2), L71, L72, and L73 have the same meaning as L1 in formula (Ia-1), and the preferred state is also the same.

[0353] Furthermore, in formula (IIa-2), in the compound PIIa-2 formed by replacing the organic cations represented by M71a+, M71b+, and M71c+ with H+, the acid dissociation constant a1-9 derived from the acidic site represented by A71aH, the acid dissociation constant a1-10 derived from the acidic site represented by A71bH, and the acid dissociation constant a1-11 derived from the acidic site represented by A71cH are equivalent to the acid dissociation constant a1. Moreover, in formula (IIa-2), the compound PIIa-2 formed by replacing the cation sites M71a+, M71b+, and M71c+ in the structural site X with H+ is equivalent to HA71a-L71-N(L73-A71cH)-L72-A71bH. Furthermore, compound PIIa-2 is the same acid produced from the compound represented by formula (IIa-2) by irradiation with photochemical rays or radiation. In addition, at least one of M71a+, M71b+, M71c+, A71a-, A71b-, A71c-, L71, L72, and L73 may have an acid-decomposing group as a substituent.

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

[0355] [Chemical 70]

[0356] [Chemistry 71]

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

[0135] to

[0171] of International Publication No. 2018 / 193954, paragraphs

[0077] to

[0116] of International Publication No. 2020 / 066824, paragraphs

[0018] to

[0075] of International Publication No. 2017 / 154345, and paragraphs

[0334] to

[0335] .

[0358] The content of compound (B) in the resist composition is not particularly limited, but in terms of further rectangularizing the cross-sectional shape of the formed 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, relative to all solid components 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, relative to all solid components of the resist composition. Compound (B) may be used alone or in combination with two or more compounds.

[0359] In addition, compound (B) may also be compound (X) as described below.

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

[0361] [Chemistry 72]

[0362] In formula (X), ArX represents an aryl group substituted with a halogen atom. The aryl group represented by ArX can be monocyclic or polycyclic. Furthermore, the aryl group can be a heterocycle containing an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of such heterocycles include: pyrrole rings, furan rings, thiophene rings, indole rings, benzofuran rings, and benzothiophene rings. The number of carbon atoms in the aryl group (the number of carbon atoms in ArX) is preferably 6 to 20, more preferably 6 to 15, and even more preferably 6 to 10.

[0363] The term "group containing a halogen atom" refers to the halogen atom itself and groups containing a halogen atom as a substituent. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine, with fluorine or iodine being more preferred. Examples of groups containing a halogen atom include halogen atoms, alkyl halides, alkoxy halides, and aryl halides. The number of halogen atoms in the aryl group is preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 10. The number of groups containing halogen atoms in the aryl group is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3. In addition to substituting for groups containing halogen atoms, the aryl group may also substituting for groups that do not contain halogen atoms. The group that does not contain 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 or naphthyl group, more preferably a phenyl group.

[0364] RX11 to RX16 each independently represent a hydrogen atom or a hydrocarbon group. At least one of RX11 to RX12 is preferably a hydrocarbon group. RX13 to RX16 preferably represent hydrogen atoms. The hydrocarbon group can be linear, branched, or cyclic. Examples of the hydrocarbon group include alkyl, cycloalkyl, alkenyl, and aryl, with alkyl being preferred. The hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 5. RX11 and RX12 can be bonded to each other to form a ring, and RX11 and at least one of RX13 to RX16, or RX12 and at least one of RX13 to RX16, can be bonded to each other to form a ring.

[0365] n and m each independently represent an integer greater than or equal to 1. Preferably, n and m are 1 to 10, more preferably 1 to 5, further preferably 1 to 3, and most preferably 2. Alternatively, n and m preferably represent the same integer. When n represents an integer greater than or equal to 2, two or more RX13s and two or more RX14s may be the same or different. Similarly, when m represents an integer greater than or equal to 2, two or more RX15s and two or more RX16s may be the same or different.

[0366] LX represents a divalent linker. Examples of divalent linkers include: -CO-, -NRA-, -O-, -S-, -SO-, -SO2-, -N(SO2-RA)-, alkylene groups, cycloalkylene groups, alkenyl groups, and divalent linkers formed by combinations of these, preferably divalent linkers containing an oxygen atom. Examples of divalent linkers containing an oxygen atom include: -CO-, -O-, -SO-, -SO2-, -N(SO2-RA)-, and divalent linkers formed by combinations of these. RA can be represented by a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Among these, divalent linkers containing an oxygen atom are preferably -O-, -CO-, or -N(SO2-RA)-, and more preferably -O- or -CO-. A divalent linker containing an oxygen atom refers to the oxygen atom itself, as well as a divalent linker containing an oxygen atom as part of the divalent linker. The number of oxygen atoms in the divalent linker containing an oxygen atom is preferably 1 to 3, more preferably 1 to 2, and even more preferably 1.

[0367] Preferably, the cation represented by formula (X-1) is a specific cation.

[0368] [Chemistry 73]

[0369] In formula (X-1), X1 represents a base containing halogen atoms. X1 has the same meaning as the halogen-containing base Arx in formula (X), and the preferred range is also the same.

[0370] Y1 represents a group that does not contain a halogen atom. Preferably, the group that does not contain a halogen atom is an alkyl group (preferably having 1 to 6 carbon atoms), an alkoxy group, or an alkoxycarbonyl group, and more preferably an alkyl group (preferably having 1 to 6 carbon atoms) or an alkoxy group. A group that does not contain a halogen atom as part of a substituent means a group that does not contain a halogen atom as 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 from 1 to 5, b represents an integer from 0 to 4, and a+b is 1 to 5. Preferably, a is 1 to 4. Preferably, b is 1 to 4.

[0372] RX20 to RX29 each independently represent a hydrogen atom or a hydrocarbon group. RX20 to RX21 have the same meaning as RX11 to RX12 in the aforementioned formula (X), and the preferred range is also the same. The hydrocarbon groups represented by RX22 to RX29 can be linear, branched, or cyclic. Examples of hydrocarbon groups represented by RX22 to RX29 include alkyl, cycloalkyl, alkenyl, and aryl groups, with alkyl being preferred. The number of carbon atoms in the hydrocarbon groups represented by RX22 to RX29 is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. RX20 and RX21 can be bonded to each other to form a ring, and RX20 and at least one of RX22 to RX25, or RX21 and at least one of RX26 to RX29 can be bonded to each other to form a ring.

[0373] A specific cation may be used alone or in combination with two or more.

[0374] The molecular weight of 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 compound (X) is the same as the preferred range of the content of compound (B). Compound (X) may be used alone or in combination with two or more other compounds. When two or more compounds are used, their combined content is preferably within the range of the preferred content.

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

[0377] [Chemical 74]

[0378] [Chemical 75]

[0379] [Acid Diffusion Control Agent] The resist composition may include an acid diffusion control agent. The acid diffusion control agent functions as a quencher, capturing acids generated during exposure from photoacid generators, etc., and inhibiting the reaction of acid-degrading resin in unexposed areas caused by excess generated acid. Examples of acid diffusion control agents include, for instance, basic compounds (CA); low-molecular-weight compounds (CB) having nitrogen atoms and groups that are removed by the action of acid; and compounds (CC) whose acid diffusion control function is reduced or eliminated by irradiation with photochemical rays or radiation. Examples of such compounds (CC) include, for instance, onium salt compounds (CD) that are relatively weak acids relative to photoacid generators, and basic compounds (CE) whose basicity is reduced or eliminated by irradiation with photochemical rays or radiation. Known acid diffusion control agents may be suitable as acid diffusion control agents. For example, well-known compounds disclosed in paragraphs

[0627] to

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

[0095] to

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

[0403] to

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

[0259] to

[0328] of U.S. Patent Application Publication 2016 / 0274458A1 can be used as acid diffusion control agents. Furthermore, as specific examples of basic compounds (CA), those described in paragraphs

[0132] to

[0136] of International Publication No. 2020 / 066824 can be cited; as specific examples of basic compounds (CD) whose alkalinity is reduced or eliminated by irradiation with photochemical rays or radiation can be cited in paragraphs

[0137] to

[0155] of International Publication No. 2020 / 066824; as specific examples of low molecular weight compounds (CB) having nitrogen atoms and having groups that are removed by the action of acids can be cited in paragraphs

[0156] to

[0163] of International Publication No. 2020 / 066824; and as specific examples of onium salt compounds (CE) having nitrogen atoms in the cation portion can be cited in paragraph

[0164] of International Publication No. 2020 / 066824. Furthermore, specific examples of onium salt compounds (CDs) that are relatively weak acids relative to photoacid generators can be cited from paragraphs

[0305] to

[0314] of International Publication No. 2020 / 158337, paragraphs

[0455] to

[0464] of International Publication No. 2020 / 158467, paragraphs

[0298] to

[0307] of International Publication No. 2020 / 158366, and paragraphs

[0357] to

[0366] of International Publication No. 2020 / 158417.

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

[0381] [Hydrophobic Resin (D)] The resist composition may further include a hydrophobic resin different from the resin (A). The hydrophobic resin is preferably designed to be present on the surface of the resist film, but unlike surfactants, it does not necessarily need to have hydrophilic groups within its molecules, and may not contribute to the uniform mixing of polar and non-polar substances. Effects of adding a hydrophobic resin include controlling the static and dynamic contact angle of the resist film surface relative to water, and suppressing gas escape.

[0382] Regarding the presence of the hydrophobic resin on the film surface, it is preferable that the hydrophobic resin has one or more of the following structures: fluorine atoms, silicon atoms, and CH3 moieties contained in the side chain portion of the resin; more preferably, it has two or more of these. Furthermore, the hydrophobic resin is preferably a hydrocarbon group having five or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted in the side chain. Examples of hydrophobic resins include compounds described in paragraphs

[0275] to

[0279] of International Publication No. 2020 / 004306.

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

[0384] 〔Surfactant (E)〕 The resist composition may contain a surfactant. If a surfactant is contained, a pattern with better adhesion and fewer development defects can be formed. The surfactant is preferably a fluorine-based and / or silicon-based surfactant. As fluorine-based and / or silicon-based surfactants, the surfactants disclosed in paragraphs

[0218] and

[0219] of International Publication No. 2018 / 19395 can be cited.

[0385] These surfactants may be used alone or in combination with more than one type.

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

[0387] 〔Other Additives〕 The resist composition may further include a solubility-inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and / or a compound that promotes solubility relative to the developer (e.g., a phenolic compound with a molecular weight of less than 1000, or an alicyclic or aliphatic compound containing a carboxyl group).

[0388] The resist composition may further include a solubility-inhibiting compound. Here, "soil-inhibiting compound" refers to a compound with a molecular weight of 3000 or less that decomposes under the action of acid and has reduced solubility in organic developer solutions.

[0389] The resist composition of the present invention can be preferably used as a photosensitive composition for EUV light. EUV light has a wavelength of 13.5 nm, which is shorter than that of ArF light (wavelength 193 nm), resulting in fewer incident photons when exposed at the same sensitivity. Therefore, the influence of "photon shot noise," which causes random dispersion of photons, is significant, leading to deterioration of LER and bridging defects. In order to reduce photon shot noise, there are methods to increase the exposure to increase the number of incident photons, but this is a trade-off with the requirement of high sensitivity.

[0390] When the A value obtained by using the following formula (1) is high, the absorption efficiency of EUV light and electron beam of the resist film formed by the resist composition is higher, which is effective in reducing photon shot noise. The A value represents the absorption efficiency of EUV light and electron beam of the resist film by mass ratio. 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 A value is preferably 0.120 or higher. There is no particular upper limit. However, if the A value is too large, the transmittance of EUV light and electron beam in the resist film will decrease, the optical image profile in the resist film will deteriorate, and it will be difficult to obtain a good pattern shape. Therefore, it is better to be below 0.240, and more preferably below 0.220.

[0391] Furthermore, in formula (1), [H] represents the molar ratio of hydrogen atoms originating from all solid components to all atoms of all solid components in the photosensitive or radiosensitive linear resin composition; [C] represents the molar ratio of carbon atoms originating from all solid components to all atoms of all solid components in the photosensitive or radiosensitive linear resin composition; [N] represents the molar ratio of nitrogen atoms originating from all solid components to all atoms of all solid components in the photosensitive or radiosensitive linear resin composition; and [O] represents the molar ratio of oxygen atoms originating from all solid components to all atoms of all solid components in the photosensitive or radiosensitive linear resin composition. The molar ratio of all atoms of all solid components in a photosensitive or radiosensitive linear resin composition, where [F] represents the molar ratio of fluorine atoms originating from all solid components relative to all atoms of all solid components in the photosensitive or radiosensitive linear resin composition, [S] represents the molar ratio of sulfur atoms originating from all solid components relative to all atoms of all solid components in the photosensitive or radiosensitive linear resin composition, and [I] represents the molar ratio of iodine atoms originating from all solid components relative to all atoms of all solid components in the photosensitive or radiosensitive linear resin composition. For example, in a resist composition containing a resin whose polarity increases by the action of acid (acid-degradable resin), a photoacid generator, an acid diffusion control agent, and a solvent, the resin, the photoacid generator, and the acid diffusion control agent are equivalent to solid components. That is, the so-called all atoms of all solid components are equivalent to the sum of all atoms originating from the resin, all atoms originating from the photoacid generator, and all atoms originating from the acid diffusion control agent. For example, [H] represents the molar ratio of hydrogen atoms originating from all solid components to all atoms of all solid components. If the example is used as a basis, then [H] represents the molar ratio of the total hydrogen atoms originating from the resin, the hydrogen atoms originating from the photoacid generator, and the hydrogen atoms originating from the acid diffusion control agent to the total of all atoms originating from the resin, the photoacid generator, and the acid diffusion control agent.

[0392] Regarding the calculation of the A value, if the structure and content of all solid components in the resist composition are known, the atomic ratio can be calculated. Furthermore, even if the constituent components are unknown, the atomic ratio can be calculated using analytical methods such as elemental analysis for resist films obtained by evaporating the solvent components of the resist composition.

[0393] [Manufacturing Method of Electronic Component] Furthermore, the present invention also relates to a manufacturing method of an electronic component including the aforementioned pattern forming method, and an electronic component manufactured by the aforementioned manufacturing method. Preferred examples of the electronic component of the present invention include those mounted in electrical and electronic equipment (home appliances, office automation (OA), media-related equipment, optical equipment, and communication equipment, etc.). [Examples]

[0394] The present invention will be further described in detail below based on embodiments. The materials, amounts, proportions, processing contents, and processing procedures shown in the following embodiments may be appropriately modified without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as limited by the embodiments shown below.

[0395] [Various components of the resist composition] [Resin] Resins Pol-1 to Pol-32 are synthesized using known methods. Tables 1 and 2 show the ratio (content ratio (moles%)), weight-average molecular weight (Mw), and dispersibility (Mw / Mn) of each repeating unit. The weight-average molecular weight (Mw) and dispersibility (Mw / Mn) of resins Pol-1 to Pol-32 were determined by GPC (carrier: tetrahydrofuran (THF)) (converted to polystyrene). In addition, the ratio of each unit was determined by carbon nuclear magnetic resonance (13C-NMR).

[0396] [Table 1] resin Unit 1 Unit 1 ratio (Moll%) Unit 2 Unit 2 ratio (Moll%) Unit 3 Unit 3 ratio (Moll%) Unit 4 Unit 4 ratio (Moll%) Mw Mw / Mn Pol-01 U-01 50 U-19 50 - - - - 8700 1.23 Pol-02 U-02 60 U-26 10 U-21 30 - - 12700 1.40 Pol-03 U-03 40 U-25 30 U-23 30 - - 14000 1.45 Pol-04 U-04 65 U-24 15 U-22 20 - - 11300 1.32 Pol-05 U-05 35 U-29 15 U-20 50 - - 7300 1.44 Pol-06 U-06 45 U-28 35 U-35 20 - - 11700 1.22 Pol-07 U-07 55 U-27 10 U-37 35 - - 6200 1.45 Pol-08 U-08 65 U-34 35 - - - - 15000 1.40 Pol-09 U-09 70 U-32 30 - - - - 15000 1.34 Pol-10 U-10 35 U-30 5 U-19 60 - - 10300 1.21 Pol-11 U-11 65 U-20 30 U-33 5 - - 15800 1.46 Pol-12 U-12 70 U-21 30 - - - - 13000 1.49 Pol-13 U-13 40 U-24 20 U-22 40 - - 10100 1.28 Pol-14 U-01 30 U-25 10 U-23 30 U-09 30 14000 1.56 Pol-15 U-03 45 U-35 55 - - - - 15300 1.25 Pol-16 U-05 35 U-37 15 U-38 30 U-10 20 12600 1.53 Pol-17 U-07 65 U-28 35 - - - - 11500 1.29 Sex-18 U-09 40 U-30 50 U-31 10 - - 14700 1.50 Gender-19 U-11 50 U-30 50 - - - - 15500 1.45 Half-20 U-13 45 U-33 30 U-36 25 - - 6200 1.58 Gender-21 U-14 40 U-19 60 - - - - 12100 1.40 Pol-22 U-15 50 U-30 10 U-19 40 - - 10100 1.46 Gender-23 U-16 65 U-25 20 U-23 15 - - 10100 1.59 Pol-24 U-17 50 U-35 50 - - - - 8800 1.23 Pol-25 U-18 40 U-33 30 U-36 30 - - 8900 1.53 Pol-26 U-19 50 U-20 50 - - - - 11500 1.20

[0397] [Table 2] Resin Unit 1 Unit 1 ratio (Moll%) Unit 2 Unit 2 ratio (Moll%) Third Unit Third Unit ratio (Moll%) Unit 4 Unit 4 ratio (Moll%) Unit 5 Unit 5 ratio (Moll%) Mw Mw / Mn Pol-27 U-02 30 U-10 30 U-29 20 U-35 20 - - 11300 1.32 Pol-28 U-42 25 U-43 35 U-19 35 U-38 5 - - 7300 1.44 Gender-29 U-42 60 U-19 20 U-26 20 - - - - 11700 1.22 Half-30 U-40 25 U-04 30 U-20 30 U-26 15 - - 6200 1.45 Gender-31 U-41 25 U-04 20 U-45 10 U-44 10 U-19 35 10100 1.28 Pol-32 U-41 33 U-03 14 U-39 2 U-28 16 U-19 35 10100 1.28

[0398] The following shows the structural formulas of the repeating units (units) shown in Table 1 and Table 2.

[0399] [Chemistry 76]

[0400] [Chemistry 77]

[0401] 〔Photoacid Generator〕 The structure of the photoacid generators (PAG-1 to PAG-27) used is shown below.

[0402] [Chemical 78]

[0403] [Chemistry 79]

[0404] [Chemical 80]

[0405] [Chemical 81]

[0406] The molecular weights of the acids produced by the photoacid generators are shown in Tables 3 and 4 below.

[0407] [Table 3] Photoacid generator The molecular weight of the acid produced PAG-1 200 PAG-2 322 PAG-3 324 PAG-4 405 PAG-5 653 PAG-6 336 PAG-7 356 PAG-8 304 PAG-9 394 PAG-10 472 PAG-11 517 PAG-12 421 PAG-13 428 PAG-14 541 PAG-15 742 PAG-16 493 PAG-17 531 PAG-18 393 PAG-19 322 PAG-20 458 PAG-21 725

[0408] [Table 4] Photoacid generator The molecular weight of the acid produced PAG-22 468 PAG-23 468 PAG-24 795 PAG-25 440 PAG-26 348 PAG-27 906

[0409] 〔Acid diffusion control agents, other additives〕 The structures of the acid diffusion control agents (PQ-01~PQ-08, Q-01~Q-04) and other additives (CL-1) used are shown below. In addition, E-3 is PF656 (manufactured by OMNOVA, a fluorinated surfactant).

[0410] [Chemical 82]

[0411] [Chemistry 83]

[0412] 〔Hydrophobic Resins〕 Hydrophobic resins D-1 to D-3 were synthesized using a known method. Table 5 shows the ratio (content ratio (moles%)), weight average molecular weight (Mw), and dispersibility (Mw / Mn) of each repeating unit. The weight average molecular weight (Mw) and dispersibility (Mw / Mn) of hydrophobic resins D-1 to D-3 were determined by GPC (carrier: tetrahydrofuran (THF)) (converted to polystyrene). In addition, the composition ratio (mole ratio) of the resins was determined by 13C-NMR (nuclear magnetic resonance).

[0413] [Table 5] hydrophobic resin Unit 1 Unit 1 ratio (Moll%) Unit 2 Unit 2 ratio (Moll%) Unit 3 Unit 3 ratio (Moll%) Unit 4 Unit 4 ratio (Moll%) Mw Mw / Mn D-1 ME-1 50 ME-6 50 - - - - 12000 1.5 D-2 ME-2 40 ME-7 50 ME-3 5 ME-5 5 6000 1.3 D-3 ME-8 85 ME-4 15 - - - - 11000 1.4

[0414] The following shows the structural formula of the repeating unit (unit) shown in Table 5.

[0415] [Chemical 84]

[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-Hepanoone F-7: Ethyl lactate F-8: γ-Butyrolactone F-9: Propylene carbonate

[0417] [Preparation of Resist Compositions] The components shown in Tables 6, 7, and 8 were dissolved in the solvents shown in Tables 6, 7, and 8, and filtered using a polyethylene filter with a fine pore size of 0.03 μm to prepare the resist compositions (Res-01 to Res-52). 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] corrosion inhibitor Composition Resin 1 Resin 2 Photoacid generator 1 Photoacid generator 2 Acid diffusion inhibitor Other additives solvent type content (by weight) type content (by weight) type content (by weight) type content (by weight) type content (by weight) type content (by weight) type content (by weight) Res-01 Pol-01 85.4 - PAG-1 12.5 - Q-03 2.1 - F-1 / F-4 2940 / 1960 Res-02 Pol-01 86.1 D-3 2.0 PAG-2 8.3 - Q-04 3.6 - F-1 / F-2 4410 / 490 Res-03 Pol-01 78.9 - PAG-3 19.6 - Q-01 1.5 - F-1 / F-2 / F-8 3920 / 735 / 245 Res-04 Pol-01 61.0 - PAG-4 28.7 - PQ-01 10.3 - F-1 / F-2 3430 / 1470 Res-05 Pol-01 67.8 - PAG-5 19.9 - PQ-02 12.3 - F-1 / F-6 4410 / 490 Res-06 Pol-01 55.8 - PAG-6 37.7 - PQ-03 6.5 - F-1 / F-2 3920 / 980 Res-07 Pol-01 67.6 - PAG-7 17.4 - PQ-04 15.0 - F-1 / F-5 3920 / 980 Res-08 Pol-01 22.9 Pol-09 31.4 PAG-8 44.2 - Q-01 1.5 - F-1 / F-2 2940 / 1960 Res-09 Pol-01 89.5 - PAG-9 9.6 - Q-02 0.9 - F-1∕F-2∕F-8 3920 / 735 / 245 Res-10 Pol-01 63.3 - PAG-10 34.5 - Q-03 2.2 - F-1∕F-2∕F-4 980 / 980∕2940 Res-11 Pol-01 72.7 - PAG-11 19.9 PAG-9 3.8 Q-04 3.6 - F-1 / F-2 2940 / 1960 Res-12 Pol-01 72.5 - PAG-12 27.5 - - - F-1∕F-2∕F-8 3920 / 735 / 245 Res-13 Pol-01 43.7 Pol-06 13.3 PAG-13 43.0 - - - F-1∕F-2∕F-8 4165 / 490 / 245 Res-14 Pol-01 61.3 - PAG-14 38.7 - - - F-1 / F-2 3920 / 980 Res-15 Pol-01 58.6 - PAG-15 41.3 - - E-3 0.1 F-1∕F-2∕F-9 4165 / 490 / 245 Res-16 Pol-01 63.8 - PAG-16 36.2 - - - F-1 / F-2 / F-4 980 / 980 / 2940 Res-17 Pol-01 54.0 - PAG-17 31.0 - PQ-01 15.0 - F-1 / F-2 3430 / 1470 Res-18 Pol-01 61.7 - PAG-18 25.0 - PQ-02 13.3 - F-1F-8 4753 / 147 Res-19 Pol-01 59.4 D-1 0.9 PAG-19 39.7 - - - F-1 / F-2 4410 / 490 Res-20 Pol-01 41.4 - PAG-20 53.5 PAG-10 5.1 - - F-1 / F-2 4410 / 490 Res-21 Pol-01 51.7 - PAG-21 44.1 - Q-03 4.2 - F-1 / F-8 4753 / 147 Res-22 Pol-02 43.7 - PAG-9 41.8 - PQ-01 14.5 - F-1 / F-4 2940 / 1960 Res-23 Pol-03 51.5 - PAG-10 38.3 - PQ-02 10.2 - F-1 / F-2 / F-8 3920 / 490 / 490

[0419] [Table 7] Anti-corrosion agent Components Resin 1 Resin 2 Photonic acid generator 1 Photonic acid generator 2 Acid diffusion inhibitor Other additives solvent type content (by weight) type content (by weight) type content (by weight) type content (by weight) type content (by weight) type content (by weight) type content (by weight) Res-24 Pol-04 81.1 - PAG-14 18.9 - - - F-1 / F-5 2940 / 1960 Res-25 Pol-05 72.9 - PAG-21 27.1 - - - F-1 / F-2 / F-8 4165 / 490 / 245 Res-26 Pol-06 69.1 - PAG-9 21.0 - PQ-03 9.9 - F-1 / F-2 3920 / 980 Res-27 Pol-07 84.7 - PAG-10 11.8 - PQ-04 3.5 - F-1 / F-2 2940 / 1960 Res-28 Pol-08 38.8 - PAG-14 61.2 - - - F-1 / F-2 4410 / 490 Res-29 Pol-09 51.5 D-2 1.1 PAG-21 38.3 PAG-6 5.6 PQ-04 3.5 - F-1 / F-2 / F-8 3920 / 490 / 490 Res-30 Pol-10 71.2 - PAG-9 14.4 - PQ-01 14.4 - F-1 / F-2 / F-8 3920 / 490 / 490 Res-31 Pol-11 54.8 - PAG-10 31.7 - PQ-02 13.5 - F-1 / F-2 / F-8 4165 / 490 / 245 Res-32 Pol-12 73.1 - PAG-14 26.9 - - - F-1 / F-4 3920 / 980 Res-33 Pol-13 84.3 - PAG-21 15.7 - - - F-1 / F-2 3920 / 980 Res-34 Pol-14 48.2 - PAG-9 36.9 - PQ-03 14.9 - F-1 / F-9 4753 / 147 Res-35 Pol-15 43.0 - PAG-10 43.1 - PQ-04 13.9 - F-1 / F-5 3920 / 980 Res-36 Pol-16 74.5 - PAG-14 25.5 - - - F-1 / F-4 3920 / 980 Res-37 Pol-17 75.3 - PAG-21 24.7 - - - F-1 / F-2 4410 / 490 Res-38 Pol-18 58.0 - PAG-14 42.0 - - - F-1 / F-2 / F-8 3920 / 490 / 490 Res-39 Pol-19 72.5 - PAG-21 27.5 - - - F-1 / F-6 3430 / 1470 Res-40 Pol-20 79.3 - PAG-9 10.5 - PQ-01 10.2 - F-1 / F-8 4753 / 147 Res-41 Pol-21 44.1 - PAG-10 43.6 - PQ-02 12.3 - F-1 / F-9 4753 / 147 Res-42 Pol-22 75.2 - PAG-14 24.8 - - - F-1 / F-2 / F-8 4165 / 490 / 245 Res-43 Pol-23 66.3 - PAG-20 33.7 - - - F-1 / F-2 4410 / 490 Res-44 Pol-24 80.1 - PAG-21 19.9 - - - F-1 / F-2 3920 / 980 Res-45 Pol-25 82.4 - PAG-9 17.1 - PQ-01 0.5 - F-1 / F-2 / F-8 4165 / 490 / 245 Res-46 Pol-26 81.7 - PAG-9 17.1 - PQ-03 1.0 CL-1 0.2 F-1 / F-5 3920 / 980

[0420] [Table 8] corrosion inhibitor Composition Resin 1 Resin 2 Photoacid generator 1 Photoacid generator 2 Acid diffusion inhibitor Other additives solvent type content (by weight) type content (by weight) type content (by weight) type content (by weight) type content (by weight) type content (by weight) type content (by weight) Res-47 Pol-27 73.0 - PAG-22 20.0 - PQ-05 7.0 - F-1 / F-2 3430 / 1470 Res-48 Pol-28 68.0 - PAG-23 25.0 - PQ-06 7.0 - F-1 / F-2 3430 / 1470 Res-49 Pol-29 78.0 - PAG-25 15.0 - PQ-07 7.0 - F-1 / F-3 3430 / 1470 Res-50 Pol-30 63.0 - PAG-27 30.0 - PQ-08 7.0 - F-1 / F-7 3430 / 1470 Res-51 Pol-31 69.0 - PAG-26 25.0 - PQ-05 6.0 - F-1 / F-2 3430 / 1470 Res-52 Pol-32 68.0 - PAG-24 24.0 - PQ-05 8.0 - F-1 / F-2 3430 / 1470

[0421] [Preparation of Organic Processing Solution] Prepare an organic processing solution (R-01 to R-19) by mixing the organic solvents listed in Table 9 below in the manner described in Table 9. Use the obtained organic processing solution as a developing solution or rinsing solution as described later.

[0422] [Table 9] Organic treatment solution First solvent Second solvent type Content (quality%) type Content (quality%) R-01 Butyl acetate 95 Undecane 5 R-02 Butyl acetate 90 Undecane 10 R-03 Butyl acetate 85 Undecane 15 R-04 Butyl acetate 80 Undecane 20 R-05 Butyl acetate 75 Undecane 25 R-06 Butyl acetate 70 Undecane 30 R-07 Butyl acetate 65 Undecane 35 R-08 Butyl acetate 85 dodecane 15 R-09 Butyl acetate 60 Undecane 40 R-10 Butyl acetate 90 decane 10 R-11 Isoamyl acetate 90 Undecane 10 R-12 Butyl acetate 100 - - R-13 Isoamyl acetate 100 - - R-14 Methylpentyl ketone 100 - - R-15 Isobutyl propionate 100 - - R-16 Butyl acetate 20 Isoamyl acetate 80 R-17 Undecane 100 - - R-18 Diisopentyl ether 100 - - R-19 Butyl acetate 80 Diisopentyl ether 20

[0423] [Formation, Patterning, and Development of Resist Film] An organic film AL412 (manufactured by Brewer Science) was coated on a silicon wafer and baked at 205°C for 60 seconds to form a film with a thickness of 5 nm. The resist compositions prepared as described in Tables 10 and 11 were then coated on the coated film and baked at the temperatures described in Tables 10 and 11 for 60 seconds (PB) to form a resist film with a thickness of 40 nm. Using an EUV exposure apparatus (manufactured by Exitech, Micro Exposure Tool, NA 0.3, Quadrupole, outer sigma 0.68, inner sigma 0.36), the silicon wafer with the obtained resist film was patterned on its entire surface with the same exposure. Furthermore, a mask with a line width of 20 nm and a line-to-space ratio of 1:1 is used as the reticle. After irradiation, the wafer is baked (PEB) for 60 seconds at the temperatures described in Tables 10 and 11 on a heated plate. Subsequently, the wafer is developed by applying the developer described in Tables 10 and 11 for 30 seconds, and after the rinsing solution described in Tables 10 and 11 flows over the wafer, the wafer is rotated for 30 seconds, and then baked at 100°C for 60 seconds, thereby obtaining a 1:1 line-to-space pattern with a line width of 20 nm.

[0424] [Evaluation of In-Plane Uniformity of Linewidth] The linewidth of the obtained lines and spatial patterns was measured using a length-measuring scanning electron microscope (SEM, Hitachi S-9380II). Specifically, 3σ, which is three times the standard deviation (σ) of the measured linewidth, was used as an indicator of the in-plane uniformity of the linewidth. Specifically, an exposure area of ​​3.5 mm in the vertical (y-axis direction) and 6.5 mm in the horizontal (x-axis direction) was defined as one exposure area (shot). Exposure was performed on the wafer in 8 rows in the x-direction and 29 columns in the y-direction, for a total of 232 exposure areas. Ten length-measuring photographs (5 lines per photograph) were taken in each exposure area, and the average of the 10 length-measuring values ​​was taken as the length-measuring value of that exposure area. The standard deviation of the length-measuring values ​​of the 232 exposure areas was multiplied by 3, which was taken as 3σ. The results are shown in Tables 10 and 11. The unit of the in-plane uniformity of linewidth in Tables 10 and 11 below is "nm".

[0425] [Table 10] corrosion inhibitor Composition PB PEB Developer Rinse solution line width In-plane uniformity Example 1 Res-01 90℃ 80℃ R-12 R-01 0.36 Example 2 Res-02 110℃ 120℃ R-02 - 0.36 Example 3 Res-03 120℃ 80℃ R-13 R-03 0.34 Example 4 Res-04 130℃ 130℃ R-14 R-04 0.24 Example 5 Res-05 80℃ 100℃ R-05 - 0.24 Example 6 Res-06 110℃ 130℃ R-12 R-06 0.24 Example 7 Res-07 100℃ 80℃ R-19 R-07 0.24 Example 8 Res-08 120℃ 130℃ R-01 R-17 0.32 Example 9 Res-09 130℃ 100℃ R-12 R-02 0.35 Example 10 Res-10 130℃ 120℃ R-12 R-03 0.30 Example 11 Res-11 120℃ 80℃ R-01 R-05 0.30 Example 12 Res-12 120℃ 100℃ R-13 R-06 0.24 Example 13 Res-13 130℃ 110℃ R-12 R-01 0.24 Example 14 Res-14 120℃ 90℃ R-13 R-02 0.22 Example 15 Res-15 130℃ 100℃ R-03 R-18 0.22 Example 16 Res-16 110℃ 110℃ R-12 R-04 0.22 Example 17 Res-17 120℃ 110℃ R-13 R-02 0.20 Example 18 Res-18 90℃ 110℃ R-06 - 0.20 Example 19 Res-19 80℃ 80℃ R-13 R-03 0.20 Example 20 Res-20 1300℃ 110℃ R-12 R-02 0.20 Example 21 Res-21 120℃ 100℃ R-15 R-03 0.20 Example 22 Res-22 90℃ 130℃ R-02 - 0.24 Example 23 Res-23 110℃ 110℃ R-15 R-04 0.22 Example 24 Res-24 90℃ 80℃ R-12 R-05 0.22 Example 25 Res-25 80℃ 110℃ R-16 R-06 0.20 Example 26 Res-26 80℃ 100℃ R-01 - 0.24 Example 27 Res-27 90℃ 100℃ R-12 R-02 0.22 Example 28 Res-28 130℃ 100℃ R-01 R-07 0.22 Example 29 Res-29 80℃ 130℃ R-02 - 0.20 Example 30 Res-30 130℃ 80℃ R-14 R-02 0.24 Example 31 Res-31 110℃ 120℃ R-12 R-07 0.22 Example 32 Res-32 90℃ 120℃ R-12 R-02 0.22 Example 33 Res-33 130℃ 130℃ R-12 R-02 0.20 Example 34 Res-34 110℃ 120℃ R-16 R-03 0.24 Example 35 Res-35 90℃ 90℃ R-12 R-04 0.22 Example 36 Res-36 130℃ 100℃ R-01 - 0.22 Example 37 Res-37 80℃ 120℃ R-12 R-07 0.20 Example 38 Res-38 100℃ 90℃ R-02 - 0.22 Example 39 Res-39 80℃ 100℃ R-01 - 0.20 Example 40 Res-40 80℃ 90℃ R-12 R-02 0.28 Example 41 Res-41 100℃ 90℃ R-12 R-01 0.26 Example 42 Res-42 120℃ 130℃ R-05 - 0.26 Example 43 Res-43 130℃ 110℃ R-12 R-05 0.24 Example 44 Res-44 90℃ 80℃ R-02 - 0.24 Example 45 Res-45 120℃ 130℃ R-12 R-02 0.37 Comparative Example 1 Res-46 90℃ 80℃ R-05 - 0.50 Example 46 Res-27 90℃ 100℃ R-12 R-08 0.31 Comparative Example 2 Res-27 90℃ 100℃ R-12 R-09 0,50 Example 3 of the shark Res-27 90℃ 100℃ R-12 R-10 0.50 Comparative Example 4 Res-27 90℃ 100℃ R-12 R-11 0.50 Comparative Example 5 Res-27 90℃ 100℃ R-12 R-12 0.50

[0426] [Table 11] corrosion inhibitor Composition PB PEB Developer Rinse solution line width In-plane uniformity Example 47 Res-47 120℃ 100℃ R-01 - 0.24 Example 48 Res-48 120℃ 100℃ R-02 - 0.24 Example 49 Res-49 120℃ 100℃ R-03 - 0.24 Example 50 Res-50 120℃ 100℃ R-04 - 0.27 Example 51 Res-51 120℃ 100℃ R-02 - 0.24 Example 52 Res-52 120℃ 100℃ R-02 - 0.24

[0427] According to the evaluation results in Tables 10 and 11, the in-plane uniformity of the linewidth of the pattern obtained in the pattern forming method of the embodiments is excellent. Both Example 5 and Comparative Example 1 were developed using organic processing solution R-05, but compared to Comparative Example 1, the in-plane uniformity of the linewidth in Example 5 was superior. This is believed to be because Comparative Example 1 used a negatively amplified chemical resist composition (Res-46) negatively amplified by a crosslinking reaction, therefore the organic processing solution R-05 did not uniformly wet and diffuse on the resist film. Both Example 27 and Comparative Examples 2 to 5 were developed using organic processing solution R-12, but compared to Comparative Examples 2 to 5, the in-plane uniformity of the linewidth in Example 27 was superior. This is believed to be because the rinsing solution used in Comparative Examples 2 to 5 was not the specific organic processing solution of the present invention, therefore it did not uniformly wet and diffuse on the resist film. [Industrial Applicability]

[0428] According to the present invention, a pattern forming method that can obtain a pattern with excellent in-plane uniformity of line width and a method for manufacturing an electronic component including the pattern forming method can be provided.

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

Claims

1. A method for forming a pattern, comprising: (1) A step of forming a film using a photosensitive or radiosensitive linear resin composition, wherein the photosensitive or radiosensitive linear resin composition comprises a resin (A) that decomposes and increases in polarity by the action of acid, and a compound (B) that generates acid by irradiation with photosensitive rays or radiation; (2) A step of exposing the film; (3) A step of developing the exposed film using an organic processing solution containing butyl acetate and undecane, wherein the content of undecane in the organic processing solution is 1% by mass or more and 35% by mass or less.

2. A method for forming a pattern, comprising: (1) A step of forming a film using a photosensitive or radiosensitive linear resin composition, wherein the photosensitive or radiosensitive linear resin composition comprises a resin (A) that decomposes and increases in polarity by the action of an acid, and a compound (B) that generates an acid by irradiation with photosensitive rays or radiation; (2) A step of exposing the film; (3) A step of developing and rinsing the exposed film using an organic processing solution containing butyl acetate and undecane, wherein the content of undecane in the organic processing solution is 10% by mass or more and 25% by mass or less.

3. The pattern forming method as described in claim 1 or claim 2, wherein, The resin (A) that decomposes and increases in polarity by the action of acid comprises at least one group selected from the group consisting of a group that substitutes a hydrogen atom of a carboxyl group with a dissociation group that is removed by the action of acid, a group that substitutes a hydrogen atom of an alcoholic hydroxyl group with a dissociation group that is removed by the action of acid, and a group that substitutes a hydrogen atom of a phenolic hydroxyl group with a dissociation group that is removed by the action of acid.

4. The pattern forming method as described in claim 1 or claim 2, wherein, The resin (A) that decomposes and increases in polarity by the action of acid has repeating units represented by the following general formula (AX), in which Xa1 represents a hydrogen atom or an alkyl group; Rx1 to Rx3 independently represent alkyl, cycloalkyl, alkenyl, or aryl groups; and the two Rx1 to Rx3 can be bonded together to form a ring.

5. The pattern forming method as described in claim 1 or claim 2, wherein, The resin (A) that decomposes and increases in polarity by the action of acid has at least one selected from the group consisting of lactone group, carbonate group, sulcinolone group, and cyclic group having hydroxyl group.

6. The pattern forming method as described in claim 1 or claim 2, wherein, The resin (A) that decomposes and increases in polarity by the action of acid has repeating units represented by the following general formula (Y), in which A represents a hydrogen atom, alkyl, cycloalkyl, halogen atom, or cyano; L represents a single bond or a divalent linker having an oxygen atom; R represents a halogen atom, alkyl, cycloalkyl, aryl, alkenyl, aralkyl, alkoxy, alkylcarbonyloxy, alkylsulfonyloxy, alkyloxycarbonyl, or aryloxycarbonyl, which may be the same or different when multiple R are present; when multiple R are present, they may form a ring together; a represents an integer from 1 to 3; b represents an integer from 0 to (5-a).

7. The pattern forming method as described in claim 1 or claim 2, wherein, The compound (B) that produces an acid by irradiation with photochemical rays or radiation has a cation represented by the following general formula (ZaI) or a cation represented by the following general formula (ZaII), in which R201, R202, and R203 each independently represent an organic group; and in which R204 and R205 each independently represent an organic group in the general formula (ZaII).

8. The pattern forming method as described in claim 7, wherein, In the general formula (ZaI), at least one of R201, R202, and R203 is aryl, or in the general formula (ZaII), at least one of R204 and R205 is aryl.

9. The pattern forming method as described in claim 7, wherein, At least one of R201, R202, and R203 in the general formula (ZaI) has an acid-decomposing group, or at least one of R204 and R205 in the general formula (ZaII) has an acid-decomposing group.

10. The pattern forming method as described in claim 1 or claim 2, wherein, The acid produced by the compound (B) which produces acid by irradiation with photochemical rays or radiation has a molecular weight of 250 or more.

11. The pattern forming method as described in claim 1 or claim 2, wherein, The content of the compound (B) that produces acid by irradiation with photosensitive rays or radiation is 10% by mass or more, relative to all solid components of the photosensitive or radiosensitive linear resin composition.

12. The pattern forming method as described in claim 1 or claim 2, wherein, The photosensitive or radiosensitive linear resin composition contains two or more of the compounds (B) that produce acids upon irradiation by photosensitive rays or radiation, or the compound (B) that produces acids upon irradiation by photosensitive rays or radiation is at least one selected from the group consisting of compounds (I) and (II) below, wherein: Compound (I): a compound having one or more structural sites X and one or more structural sites Y and producing an acid upon irradiation by photosensitive rays or radiation, the acid comprising a first acidic site derived from structural site X and a second acidic site derived from structural site Y; Structural site X: a structural site comprising an anionic site A1- and a cation site M1+, and forming a first acidic site represented by HA1 upon irradiation by photosensitive rays or radiation; Structural site Y: a structural site comprising an anionic site A2- and a cation site M2+, and forming a second acidic site represented by HA2 upon irradiation by photosensitive rays or radiation, wherein... Compound (I) satisfies the following condition I: Condition I: In compound (I), compound PI formed by replacing the cation M1+ in structural site X and the cation M2+ in structural site Y with H+ has an acid dissociation constant a1 derived from the acidic site represented by HA1, which is formed by replacing the cation M1+ in structural site X with H+, and an acid dissociation constant a2 derived from the acidic site represented by HA2, which is formed by replacing the cation M2+ in structural site Y with H+, and the acid dissociation constant a2 is greater than the acid dissociation constant a1; Compound (II): A compound having two or more structural sites X and one or more structural sites Z and producing an acid by irradiation with photochemical rays or radiation, the acid comprising two or more first acidic sites derived from structural site X and structural site Z; Structural site Z: A site capable of neutralizing the nonionic nature of the acid.

13. A method for manufacturing an electronic component, comprising a pattern forming method as described in any one of claims 1 to 12.