TW202413462A - Actinic ray-sensitive or radiation-sensitive resin composition, actinic ray-sensitive or radiation-sensitive film, pattern formation method, and electronic device manufacturing method - Google Patents

Abstract

Provided are: an actinic ray-sensitive or radiation-sensitive resin composition; and an actinic ray-sensitive or radiation-sensitive film, a pattern formation method, and an electronic device manufacturing method which use said actinic ray-sensitive or radiation-sensitive resin composition. The actinic ray-sensitive or radiation-sensitive resin composition contains a resin having a specific repeating unit (i), a specific repeating unit (ii), and a specific repeating unit (iii), wherein when the repeating unit (ii) has an acid-labile group, a repeating unit derived from the repeating unit (ii) decomposed under the action of acid does not correspond to the repeating unit (i).

Description

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

The present invention relates to an actinic radiation-sensitive or radiation-sensitive resin composition, an actinic radiation-sensitive or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device. More specifically, the present invention relates to an ultra-microphotographic process applicable to a manufacturing process of ultra-LSI (Large Scale Integration, large integrated circuit) and high-capacity microchips, a mold manufacturing process for nanoimprinting, and a manufacturing process of high-density information recording media, and an actinic radiation-sensitive or radiation-sensitive resin composition, an actinic radiation-sensitive or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device that can be preferably used in other optical processing processes.

In the past, in the manufacturing process of semiconductor devices such as IC (Integrated Circuit) and LSI (Large Scale Integration), micro-processing was performed by photolithography using photoresist compositions. In recent years, with the high integration of integrated circuits, there is a demand to form ultra-fine patterns in sub-micron areas or quarter-micron areas. Along with this, the exposure wavelength has also shown a trend of shortening from g-rays to i-rays and then to KrF excimer lasers, and currently an exposure machine with a wavelength of 193nm ArF excimer laser as the light source has been developed. In addition, as a technology to further improve resolution, the so-called liquid immersion method has been developed, in which a high-refractive-index liquid (hereinafter also referred to as "immersion liquid") is filled between the projection lens and the sample.

In addition to excimer lasers, photolithography using electron beams (EB), X-rays, and extreme ultraviolet (EUV) is also being developed. Along with this, photoresist compositions that effectively respond to various actinic rays or radiation have been developed.

For example, Patent Document 1 describes a photoresist composition containing a repeating unit having a group that generates a phenolic hydroxyl group by the action of an acid and a resin containing a phenolic hydroxyl group or a fluorinated alcohol group. [Prior Art Document] [Patent Document]

Patent Document 1: International Publication No. 2018/56369

[The problem that the invention wants to solve]

However, in the formation of extremely fine patterns (for example, line width or space width below 50nm), it is difficult to achieve a high level of line width roughness (LWR) performance, pattern shape, and stability over time. The so-called LWR performance refers to the performance that can reduce the LWR of the pattern.

The subject of the present invention is to provide an actinic radiation-sensitive or radiation-sensitive resin composition, which can take into account the LWR performance, pattern shape, and stability over time at a high level in the formation of extremely fine patterns (for example, line width or space width is less than 50nm). In addition, the subject of the present invention is to provide an actinic radiation-sensitive or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device using the above-mentioned actinic radiation-sensitive or radiation-sensitive resin composition. [Means for solving the problem]

The inventors of the present invention have found that the above-mentioned problem can be solved by the following structure.

[1] A photosensitive or radiation-sensitive resin composition, comprising a resin having the following repeating unit (i), the following repeating unit (ii) and the following repeating unit (iii). Wherein, when the repeating unit (ii) has a group that decomposes by the action of an acid, the repeating unit after the repeating unit (ii) decomposes by the action of an acid is not equivalent to the repeating unit (i). (i) A repeating unit having a phenolic hydroxyl group, and in a monomer equivalent to the above repeating unit, the ClogP value of the anionic state after the hydrogen atom of the phenolic hydroxyl group dissociates is greater than -7.50 and less than -1.20 (ii) A repeating unit having a phenolic hydroxyl group, and in a monomer equivalent to the above repeating unit, the ClogP value of the anionic state after the hydrogen atom of the phenolic hydroxyl group dissociates is greater than -0.70 and less than 5.00 (iii) A repeating unit having no phenolic hydroxyl group but having a group whose polarity increases by decomposition by the action of an acid

[2] The photosensitive or radiation-sensitive resin composition as described in [1], wherein the repeating unit (i) is a repeating unit having two or more phenolic hydroxyl groups.

[3] The photosensitive or radiation-sensitive resin composition as described in [1] or [2], wherein the repeating unit (i) is a repeating unit represented by the following general formula (a-1).

[Chemical formula 1]

In the general formula (a-1), ^Ra1 represents a hydrogen atom or an alkyl group. ^L1 represents a single bond or -C(=O)O-. m represents an integer of 0 to 2. n represents an integer of 2 to 3. ^Ra2 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group, or a group composed of two or more of these. l represents an integer of 0 to 4. When l is 2 or more, a plurality of ^Ra2 groups may be the same or different and may be bonded to each other to form a ring.

[4] The actinic radiation-sensitive or radiation-sensitive resin composition as described in any one of [1] to [3], wherein the repeating unit (ii) is a repeating unit represented by the following general formula (a-2).

[Chemical formula 2]

In the general formula (a-2), ^Ra2 represents a hydrogen atom or an alkyl group. ^L2 represents a single bond or -C(=O)O-. o represents an integer of 0 to 2. p represents an integer of 1 to 2. ^Ra4 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group, or a group composed of two or more of these. q represents an integer of 0 to 4. When q is 2 or more, a plurality of ^Ra4 groups may be the same or different and may be bonded to each other to form a ring.

[5] The photosensitive or radiation-sensitive resin composition as described in any one of [1] to [4], wherein the repeating unit (iii) is at least one repeating unit selected from the group consisting of a repeating unit represented by the following general formula (a-3) and a repeating unit represented by the following general formula (a-4).

[Chemical formula 3]

In the general formula (a-3), ^Ra5 and ^Ra15 each independently represent a hydrogen atom or an alkyl group. ^L3 represents a single bond or -C(=O)O-. r represents an integer from 0 to 2. s represents an integer from 0 to 4. ^Rp1 represents a group that is dissociated by the action of an acid. t represents an integer from 0 to 4. ^Rp2 represents a group that is dissociated by the action of an acid. At least one of s and t is an integer greater than 1. u represents an integer from 0 to (5+r×4-st). ^Ra6 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group, or a group composed of two or more of these. When u is 2 or more, a plurality of ^Ra6 groups may be the same or different, and may be bonded to each other to form a ring. Furthermore, ^Ra6 and ^Rp1 , ^Ra6 and ^Rp2 , and ^Rp1 and ^Rp2 may bond to each other to form a ring. The aromatic rings bonded to ^Ra15 and ^L3 may bond to each other to form a ring.

[Chemical formula 4]

In the general formula (a-4), R ^a7 represents a hydrogen atom or an alkyl group. R ^p3 represents a group that is released by the action of an acid.

[6] The actinic radiation-sensitive or radiation-sensitive resin composition as described in any one of [1] to [5], wherein the repeating unit (iii) is a repeating unit represented by the general formula (a-3).

[7] The actinic ray-sensitive or radiation-sensitive resin composition as described in any one of [1] to [6], wherein the repeating unit (i) and the repeating unit (ii) are repeating units that do not have a group that decomposes by the action of an acid. [8] The actinic ray-sensitive or radiation-sensitive resin composition as described in any one of [1] to [7], further comprising a compound that generates an acid by irradiation with actinic rays or radiation.

[9] A photosensitive or radiation-sensitive film, which is formed from the photosensitive or radiation-sensitive resin composition described in any one of [1] to [8]. [10] A pattern forming method, which comprises: a process of forming a photosensitive or radiation-sensitive film on a substrate from the composition described in any one of [1] to [8]; a process of exposing the photosensitive or radiation-sensitive film; and a process of developing the exposed photosensitive or radiation-sensitive film using a developer. [11] A method for manufacturing an electronic device, which comprises the pattern forming method described in [10]. [Effect of the invention]

According to the present invention, a photosensitive or radiation-sensitive resin composition can be provided, which can take into account LWR performance, pattern shape, and stability over time at a high level in the formation of extremely fine patterns (for example, line width or space width is 50nm or less). In addition, according to the present invention, a photosensitive or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device using the above-mentioned photosensitive or radiation-sensitive resin composition can be provided.

The present invention will be described in detail below. The description of the constituent elements described below is sometimes based on representative implementations of the present invention, but the present invention is not limited to such implementations.

In this specification, "actinic rays" or "radiation" means, for example, the bright line spectrum of mercury lamps, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV: Extreme Ultraviolet), X-rays, soft X-rays, and electron beams (EB: Electron Beam). In this specification, "light" means actinic rays or radiation. In this specification, "exposure" includes not only exposure using the bright line spectrum of mercury lamps, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays, X-rays and EUV, but also drawing using particle beams such as electron beams and ion beams, unless otherwise specified. In this manual, "～" is used to mean that the numerical values written before and after it are included as lower and upper limits.

In the present specification, (meth)acrylate refers to at least one of acrylate and methacrylate. Also, (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid.

In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn) and dispersion degree (also referred to as "molecular weight distribution") (Mw/Mn) of the resin are defined as polystyrene conversion values obtained by GPC measurement using a GPC (Gel Permeation Chromatography) apparatus (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40°C, flow rate: 1.0 mL/min, detector: differential refractive index detector).

Regarding the description of the groups (atomic groups) in this specification, as long as it does not violate the purpose of the present invention, the description without substitution and unsubstituted includes both groups without substituents and groups with substituents. For example, the so-called "alkyl" includes not only alkyl groups without substituents (unsubstituted alkyl groups) but also alkyl groups with substituents (substituted alkyl groups). In addition, the so-called "organic group" in this specification refers to a group containing at least one carbon atom. As a substituent, if not specifically specified, it is preferably a monovalent substituent. As an example of a substituent, a monovalent non-metallic atomic group other than a hydrogen atom can be cited, for example, it can be selected from the following substituents T.

(Substituent T) As the substituent T, there can be cited halogen atoms such as fluorine, chlorine, bromine and iodine; alkoxy groups such as methoxy, ethoxy and tert-butoxy; cycloalkoxy; aryloxy groups such as phenoxy and p-tolyloxy; alkoxycarbonyl groups such as methoxycarbonyl and butoxycarbonyl; cycloalkoxycarbonyl; aryloxycarbonyl groups such as phenoxycarbonyl; acyloxy groups such as acetyloxy, propionyloxy and benzyloxy; acetyl, benzyl, isobutyl Acyl, acryl, methacryl and methyloxalyl; sulfonyl; alkylsulfanyl such as methylsulfanyl and tert-butylsulfanyl; arylsulfanyl such as phenylsulfanyl and p-tolylsulfanyl; alkyl; alkenyl; cycloalkyl; aryl; aromatic heterocyclic; hydroxyl; carboxyl; formyl; sulfo; cyano; alkylaminocarbonyl; arylaminocarbonyl; sulfonamido; silyl; amino; aminoformyl, etc. In addition, when these substituents may further have one or more substituents, groups having one or more substituents selected from the above substituents as further substituents (for example, monoalkylamino, dialkylamino, arylamino, trifluoromethyl, etc.) are also included in the examples of substituent T.

In this specification, the bonding direction of the divalent groups described is not particularly limited unless otherwise specified. For example, in a compound represented by the formula "X-Y-Z", when Y is -COO-, Y can be either -CO-O- or -O-CO-. The above compound can be either "X-CO-O-Z" or "X-O-CO-Z".

In this manual, the acid dissociation constant (pKa) refers to the pKa in aqueous solution. Specifically, it is a value calculated using the following software package 1 based on the values of the Hammett substituent constant and the database of known literature values. The pKa values described in this manual are all values calculated using this software package. Software package 1: Advanced Chemistry Development (ACD/Labs) Software V8.14 for Solaris (1994-2007 ACD/Labs).

In addition, pKa can also be obtained using molecular orbital calculation. As a specific method, a method of calculating by calculating the H ⁺ dissociation free energy in an aqueous solution based on a thermodynamic cycle can be cited. Regarding the calculation method of H ⁺ dissociation free energy, for example, it can be calculated by DFT (density functional theory), but it is not limited to this, and there are also various other methods reported in the literature. In addition, there are many kinds of software that can implement DFT, for example, Gaussian16 can be cited.

In this specification, pKa refers to the value obtained by calculation using software package 1 based on the value of the Hammett substituent constant and the database of known literature values as described above. However, when pKa cannot be calculated using this method, the value obtained by Gaussian16 based on DFT (density functional theory) is used. In this specification, pKa refers to "pKa in aqueous solution" as described above. However, when pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" is used.

In this specification, the so-called "solid component" means a component that forms an actinic radiation or radiation-sensitive film, and does not include a solvent. In addition, as long as it is a component that forms an actinic radiation or radiation-sensitive film, it is considered a solid component even if it is in a liquid state.

<Acticular radiation-sensitive or radiation-sensitive resin composition> The actinic radiation-sensitive or radiation-sensitive resin composition of the present invention (also referred to as "the composition of the present invention") is an actinic radiation-sensitive or radiation-sensitive resin composition containing a resin having the following repeating unit (i), the following repeating unit (ii) and the following repeating unit (iii). Wherein, when the above repeating unit (ii) has a group decomposed by the action of an acid, the repeating unit after the above repeating unit (ii) is decomposed by the action of an acid is not equivalent to the above repeating unit (i). (i) is a repeating unit having a phenolic hydroxyl group, and in a monomer equivalent to the above repeating unit, the ClogP value of the anion state after the hydrogen atom of the above phenolic hydroxyl group is dissociated is greater than -7.50 and less than -1.20 (ii) A repeating unit having a phenolic hydroxyl group, and in a monomer corresponding to the repeating unit, the ClogP value of the anionic state of the hydrogen atom of the phenolic hydroxyl group after dissociation is greater than -0.70 and less than 5.00 (iii) A repeating unit having no phenolic hydroxyl group but having a group whose polarity increases by decomposition by the action of an acid

According to the composition of the present invention, an actinic radiation or radiation-sensitive resin composition can be obtained, which can take into account the LWR performance, pattern shape, and stability over time at a high level in the formation of extremely fine patterns (for example, line width or space width is 50nm or less) by adopting the above-mentioned structure. The reason is not clear, but it is speculated as follows. It is known that a resin having a repeating unit of a hydrophilic acid group such as a repeating unit derived from dihydroxystyrene (DHS) and a repeating unit having a group whose polarity increases by decomposition by the action of an acid is used in a photoresist composition, but the inventors of the present invention have found that there are problems in LWR performance, pattern shape, and stability over time. The inventors of the present invention speculate that the reason is that the group whose polarity increases due to decomposition by the action of acid is a hydrophobic group, and the difference in hydrophilicity between the hydrophilic acid group and the above hydrophobic group is large, so the compatibility of the resin is poor. In addition to the above two repeating units, the inventors of the present invention have also studied the addition of various repeating units, but the repeating units such as the repeating units derived from hydroxystyrene (PHS) still have hydrophilic acid groups and have not been improved. After in-depth research, the inventors of the present invention found that the above performance can be improved by using repeating units with acid groups that are more hydrophobic than PHS. It is believed that the hydrophilic groups derived from the acid groups in the repeating units of the above-mentioned DHS and the hydrophobic groups whose polarity increases due to decomposition by the action of acid in the repeating units having the groups whose polarity increases due to decomposition by the action of acid form appropriate hydrophilic groups, and a balance is achieved between the difference in hydrophilicity and hydrophobicity of the resin as a whole, thereby improving the compatibility. In addition, the inventors of the present invention have found that the ClogP value in each repeating unit contributes to such difference in hydrophilicity and hydrophobicity, thereby completing the present invention. The present invention contains a resin having the above-mentioned repeating unit (i), the above-mentioned repeating unit (ii), and the above-mentioned repeating unit (iii). It is believed that the above-mentioned repeating unit (i) is a repeating unit having the most hydrophilic group, and the above-mentioned repeating unit (iii) is a repeating unit having the most hydrophobic group. It is believed that the repeating unit (ii) contains a group having properties between the above two. It is believed that by using a resin having these three types of repeating units (i), repeating units (ii) and repeating units (iii), it is difficult for the repeating units (i) to aggregate with each other or for the repeating units (iii) to aggregate with each other because there is a repeating unit (ii) having properties between the repeating units (i) and the repeating units (iii) in terms of hydrophilicity. In fact, in the present invention, the compatibility between the resins tends to become very high. As a result, it is believed that according to the above structure of the present invention, it is possible to take into account LWR performance, pattern formation, and stability over time at a high level. Although the detailed reason is not clear, it is known that when the above-mentioned repeating unit (ii) contains a group that is decomposed by the action of an acid, the repeating unit (ii) after decomposition by the action of an acid is not equivalent to the repeating unit (i), thereby being able to truly realize the above-mentioned effect of the present invention.

The composition of the present invention is typically a photoresist composition, and can be a positive photoresist composition or a negative photoresist composition. The photoresist composition of the present invention can be a photoresist composition for alkaline development or a photoresist composition for organic solvent development. The photoresist composition of the present invention can be a chemically amplified photoresist composition or a non-chemically amplified photoresist composition. The composition of the present invention is typically a chemically amplified photoresist composition. The composition of the present invention can be used to form a photosensitive or radiation-sensitive film. The photosensitive or radiation-sensitive film formed using the composition of the present invention is typically a photoresist film. Below, the various components of the composition of the present invention are first described in detail.

[Resin (A)] The resin (A) contained in the composition of the present invention is a resin having the following repeating unit (i), the following repeating unit (ii) and the following repeating unit (iii). Wherein, when the above repeating unit (ii) has a group that is decomposed by the action of an acid, the repeating unit after the above repeating unit (ii) is decomposed by the action of an acid is not equivalent to the above repeating unit (i). (i) A repeating unit having a phenolic hydroxyl group, and in a monomer equivalent to the above repeating unit, the ClogP value of the anionic state after the hydrogen atom of the phenolic hydroxyl group dissociates is greater than -7.50 and less than -1.20 (ii) A repeating unit having a phenolic hydroxyl group, and in a monomer equivalent to the above repeating unit, the ClogP value of the anionic state after the hydrogen atom of the phenolic hydroxyl group dissociates is greater than -0.70 and less than 5.00 (iii) A repeating unit having no phenolic hydroxyl group but having a group whose polarity increases by decomposition by the action of an acid

Each repeating unit is described below. In this specification, a phenolic hydroxyl group refers to a hydroxyl group bonded to an aromatic hydrocarbon group. In addition, the ClopP values in the repeating unit (i) and the repeating unit (ii) are calculated using the structure of the anion state after the proton of the hydroxyl group is dissociated using ChemDraw 20.

(Repeating unit (i)) In the monomer corresponding to the repeating unit (i), the ClogP value of the anion state after the dissociation of the hydrogen atom of the phenolic hydroxyl group is -7.50 or more and less than -1.20. The ClogP value is -7.50 or more, preferably -6.00 or more, and more preferably -4.50 or more. If the ClogP value is less than -7.50, the hydrophilicity becomes too strong, and the compatibility of the obtained resin (A) may be poor. The ClogP value is less than -1.20, preferably -2.00 or less, and more preferably -3.00 or less. If the ClogP value is -1.20 or more, the polarity of the resin decreases, and the compatibility of the obtained resin (A) with the low molecular weight material used in combination may be poor. The monomer equivalent to the repeating unit (i) represents the monomer before polymerization.

The above-mentioned repeating unit (i) is preferably a repeating unit having two or more phenolic hydroxyl groups. The upper limit of the number of phenolic hydroxyl groups in the repeating unit (i) is not particularly limited, and is preferably 3. The so-called "anionic state after the hydrogen atoms of the above-mentioned phenolic hydroxyl group are dissociated" refers to the anionic state after all hydrogen atoms of the two or more phenolic hydroxyl groups are dissociated when the above-mentioned repeating unit (i) is a repeating unit having two or more phenolic hydroxyl groups.

The repeating unit (i) is preferably a repeating unit represented by the following general formula (a-1).

[Chemical formula 5]

In the general formula (a-1), ^Ra1 represents a hydrogen atom or an alkyl group. ^L1 represents a single bond or -C(=O)O-. m represents an integer of 0 to 2. n represents an integer of 2 to 3. ^Ra2 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group, or a group composed of two or more of these. l represents an integer of 0 to 4. When l is 2 or more, a plurality of ^Ra2 groups may be the same or different and may be bonded to each other to form a ring.

The alkyl group as R ^a1 may be either linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 5, more preferably 1 to 3. m represents an integer of 0 to 2, preferably 0 or 1, and more preferably 0. The aromatic ring in the general formula (a-1) is benzene when m represents 0, naphthalene when m represents 1, and anthracene when m represents 2. n represents an integer of 2 to 3, and preferably 2.

As the halogen atom of R ^a2 , for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom can be mentioned, preferably a fluorine atom or an iodine atom. As the alkyl group of R ^a2 , it can be any of a linear chain and a branched chain. The carbon number of the alkyl group is not particularly limited, preferably 1 to 10, more preferably 1 to 6. The methyl group contained in the alkyl group of R ^a2 can be substituted by at least one of -CO- and -O-. The carbon number of the cycloalkyl group of R ^a2 is not particularly limited, preferably 3 to 20, more preferably 5 to 15. As the cycloalkyl group of R ^a2 , monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl, and polycyclic cycloalkyl groups such as norbornyl, tetracyclodecyl, tetracyclododecyl and adamantyl are preferred. The alkyl group contained in the alkoxy group of R ^a2 may be either linear or branched. The carbon number of the alkyl group contained in the alkoxy group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 6. The carbon number of the aryl group contained in the aryloxy group of R ^a2 is not particularly limited, but is preferably 6 to 20, more preferably 6 to 10. The aryl group contained in the aryloxy group of R ^a2 is most preferably a phenyl group.

The alkyl group contained in the alkylthio group of R ^a2 may be any of a linear or branched chain. The carbon number of the alkyl group contained in the alkylthio group is not particularly limited, and is preferably 1 to 10, and more preferably 1 to 6. The carbon number of the aryl group contained in the arylthio group of R ^a2 is not particularly limited, and is preferably 6 to 20, and more preferably 6 to 10. The aryl group contained in the arylthio group of R ^a2 is preferably a phenyl group. The carbon number of the aryl group of R ^a2 is not particularly limited, and is preferably 6 to 20, and more preferably 6 to 10. The aryl group of R ^a2 is preferably a phenyl group. The heteroaryl group of R ^a2 preferably contains at least one heteroatom selected from the group consisting of a sulfur atom, a nitrogen atom, and an oxygen atom. The number of heteroatoms contained in the heteroaryl group is preferably 1 to 5, and more preferably 1 to 3. The number of carbon atoms in the heteroaryl group is not particularly limited, but is preferably 2 to 20, and more preferably 3 to 15. The heteroaryl group may be monocyclic or polycyclic. Examples of the heteroaryl group for R ^a2 include thienyl, furyl, benzothienyl, dibenzothienyl, benzofuranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, isothiazolyl, and thiadiazolyl.

There is no particular limitation on the groups formed by combining two or more of these groups. For example, there can be cited groups formed by combining at least one selected from the group consisting of ester groups, halogen atoms, alkyl groups, cycloalkyl groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, aryl groups, heteroaryl groups, and carboxyl groups. l represents an integer of 0 to 4, preferably an integer of 0 to 2, and more preferably 0 or 1.

The above-mentioned alkyl, cycloalkyl, alkoxy, aryloxy, alkylthio, aryl, arylthio, heteroaryl, ester, carboxyl, or a group composed of two or more of these groups may further have a substituent. R ^a2 may or may not have a group that is decomposed by the action of an acid. As a group that is decomposed by the action of an acid (acid-decomposable group), the acid-decomposable group in the following repeating unit (iii) can be cited.

The anionic state after dissociation of the hydrogen atom of the phenolic hydroxyl group in the monomer corresponding to the repeating unit (i) and the ClogP value of the anionic state are shown below, but the present invention is not limited thereto.

[Chemical formula 6]

Specific examples of the monomer corresponding to the repeating unit (i) are shown below, but the present invention is not limited thereto.

[Chemical formula 7]

The content of the repeating unit (i) is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 15 mol% or more, based on all the repeating units in the resin (A). Furthermore, the content of the repeating unit (i) is preferably 80 mol% or less, more preferably 70 mol% or less, and further preferably 60 mol% or less, based on all the repeating units in the resin (A).

The repeating unit (i) contained in the resin (A) may be one kind or two or more kinds. When two or more kinds are contained, it is preferred that the total content thereof is within the above-mentioned preferred content range.

(Repeating unit (ii)) In the monomer corresponding to the repeating unit (ii), the ClogP value of the anion state after the dissociation of the hydrogen atom of the phenolic hydroxyl group is -0.70 or more and less than 5.00. The ClogP value is -0.70 or more, preferably -0.50 or more, and more preferably 0.00 or more. If the ClogP value is less than -0.70, the hydrophilicity becomes high, and the compatibility of the obtained resin (A) may become poor. The ClogP value is less than 5.00, preferably 4.00 or less, and more preferably 2.50 or less. If the ClogP value is 5.00 or more, the hydrophobicity becomes strong, and the compatibility of the obtained resin (A) may become poor. The monomer corresponding to the repeating unit (ii) refers to the monomer before polymerization.

The above-mentioned repeating unit (ii) is a repeating unit having one phenolic hydroxyl group, and may also be a repeating unit having one or more phenolic hydroxyl groups. The upper limit of the number of phenolic hydroxyl groups in the repeating unit (ii) is not particularly limited, but is preferably two. The so-called "anionic state after the hydrogen of the above-mentioned phenolic hydroxyl group is dissociated" refers to the anionic state after all hydrogen atoms of the two phenolic hydroxyl groups are dissociated when the above-mentioned repeating unit (ii) is a repeating unit having two phenolic hydroxyl groups.

The repeating unit (ii) is preferably a repeating unit represented by the following general formula (a-2).

[Chemical formula 8]

In the general formula (a-2), ^Ra3 represents a hydrogen atom or an alkyl group. ^L2 represents a single bond or -C(=O)O-. o represents an integer of 0 to 2. p represents an integer of 1 to 2. ^Ra4 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group, or a group composed of two or more of these. q represents an integer of 0 to 4. When q is 2 or more, a plurality of ^Ra4 groups may be the same or different and may be bonded to each other to form a ring.

The alkyl group as R ^a3 may be either a linear or branched chain. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 5, more preferably 1 to 3. o represents an integer of 0 to 2, preferably 0 or 1, and more preferably 0. The aromatic ring in the general formula (a-2) is benzene when o represents 0, naphthalene when o represents 1, and anthracene when o represents 2. p represents an integer of 1 to 2, and preferably 1.

As the halogen atom of R ^a4 , for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom can be mentioned, preferably a fluorine atom or an iodine atom. As the alkyl group of R ^a4 , it can be any of a linear chain and a branched chain. The carbon number of the alkyl group is not particularly limited, preferably 1 to 10, more preferably 1 to 6. The methyl group contained in the alkyl group of R ^a4 can be substituted by at least one of -CO- and -O-. The carbon number of the cycloalkyl group of R ^a4 is not particularly limited, preferably 3 to 20, more preferably 5 to 15. As the cycloalkyl group of R ^a4 , monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl, and polycyclic cycloalkyl groups such as norbornyl, tetracyclodecyl, tetracyclododecyl and adamantyl are preferred. The alkyl group contained in the alkoxy group as R ^a4 may be either linear or branched. The carbon number of the alkyl group contained in the alkoxy group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 6. The carbon number of the aryl group contained in the aryloxy group as R ^a4 is not particularly limited, but is preferably 6 to 20, more preferably 6 to 10. The aryl group contained in the aryloxy group as R ^a2 is most preferably phenyl.

The alkyl group contained in the alkylthio group of R ^a4 may be any of a linear or branched chain. The carbon number of the alkyl group contained in the alkylthio group is not particularly limited, and is preferably 1 to 10, and more preferably 1 to 6. The carbon number of the aryl group contained in the arylthio group of R ^a4 is not particularly limited, and is preferably 6 to 20, and more preferably 6 to 10. The aryl group contained in the arylthio group of R ^a2 is preferably a phenyl group. The carbon number of the aryl group of R ^a4 is not particularly limited, and is preferably 6 to 20, and more preferably 6 to 10. The aryl group of R ^a4 is preferably a phenyl group. The heteroaryl group of R ^a4 preferably contains at least one heteroatom selected from the group consisting of a sulfur atom, a nitrogen atom, and an oxygen atom. The number of heteroatoms contained in the heteroaryl group is preferably 1 to 5, and more preferably 1 to 3. The number of carbon atoms in the heteroaryl group is not particularly limited, but is preferably 2 to 20, and more preferably 3 to 15. The heteroaryl group may be monocyclic or polycyclic. Examples of the heteroaryl group of R ^a4 include thienyl, furyl, benzothienyl, dibenzothienyl, benzofuranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, isothiazolyl, and thiadiazolyl.

There is no particular limitation on the groups formed by combining two or more of these groups. For example, there can be cited groups formed by combining at least one selected from the group consisting of an ester group, a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, and a carboxyl group. q represents an integer of 0 to 4, preferably an integer of 0 to 2, and more preferably 0 or 1.

The above-mentioned alkyl, cycloalkyl, alkoxy, aryloxy, alkylthio, arylthio, aryl, heteroaryl, ester, carboxyl, or a group composed of two or more of these groups may further have a substituent. R ^a4 may or may not have a group that is decomposed by the action of an acid. As a group that is decomposed by the action of an acid (acid-decomposable group), the acid-decomposable group in the following repeating unit (iii) can be cited. When the above-mentioned repeating unit (ii) has a group that is decomposed by the action of an acid, the repeating unit after the above-mentioned repeating unit (ii) is decomposed by the action of an acid is not equivalent to the above-mentioned repeating unit (i).

The anionic state after dissociation of the hydrogen atom of the phenolic hydroxyl group in the monomer corresponding to the repeating unit (ii) and the ClogP value of the anionic state are shown below, but the present invention is not limited thereto.

[Chemical formula 9]

Specific examples of monomers corresponding to the repeating unit (ii) are shown below, but the present invention is not limited thereto.

[Chemical formula 10]

From the viewpoints of LWR performance, pattern shape, and stability over time, the repeating unit (i) and the repeating unit (ii) are preferably repeating units having no group decomposed by the action of an acid.

The content of the repeating unit (ii) is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 15 mol% or more, based on all the repeating units in the resin (A). Furthermore, the content of the repeating unit (ii) is preferably 80 mol% or less, more preferably 70 mol% or less, and further preferably 60 mol% or less, based on all the repeating units in the resin (A).

The resin (A) may contain one or more types of the repeating unit (ii). When the resin (A) contains two or more types, the total content thereof is preferably within the above-mentioned preferred content range.

(Repeating unit (iii)) The repeating unit (iii) has a group whose polarity increases when decomposed by an acid. The resin (A) contained in the composition of the present invention is a resin containing a group whose polarity increases when decomposed by an acid (also referred to as an "acid-decomposable group"). The resin (A) is an acid-decomposable resin. In the pattern forming method using the composition of the present invention, typically, when an alkaline developer is used as a developer, a positive pattern can be formed preferably, and when an organic developer is used as a developer, a negative pattern can be formed preferably.

Typically, the acid-decomposable group is a group that decomposes by the action of an acid to generate a polar group. The acid-decomposable group preferably has a structure in which the polar group is protected by a group that is dissociated by the action of an acid (dissociation group). Typically, the polarity of the resin (A) increases by the action of an acid, thereby increasing the solubility in an alkaline developer and decreasing the solubility in an organic solvent.

As the polar group, an alkali-soluble group is preferred, and examples thereof include acidic groups such as a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group, a sulfonic acid group, a phosphoric acid group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl)(alkylcarbonyl)methyl group, an (alkylsulfonyl)(alkylcarbonyl)imide group, a bis(alkylcarbonyl)methyl group, a bis(alkylcarbonyl)imide group, a bis(alkylsulfonyl)methyl group, a bis(alkylsulfonyl)imide group, a tri(alkylcarbonyl)methyl group, and a tri(alkylsulfonyl)methyl group, and an alcoholic hydroxyl group.

As the group that is released by the action of an acid (release group), for example, groups represented by formulas (Y1) to (Y4) can be cited. Formula (Y1): -C(Rx ₁ )(Rx ₂ )(Rx ₃ ) Formula (Y2): -C(=O)OC(Rx ₁ )(Rx ₂ )(Rx ₃ ) Formula (Y3): -C(R ₃₆ )(R ₃₇ )(OR ₃₈ ) Formula (Y4): -C(Rn)(H)(Ar)

In formula (Y1) and formula (Y2), Rx ₁ to Rx ₃ each independently represent an alkyl group (straight or branched), a cycloalkyl group (monocyclic or polycyclic), an aryl group (monocyclic or polycyclic), an aralkyl group (straight or branched), or an alkenyl group (straight or branched). In addition, when all Rx ₁ to Rx ₃ are alkyl groups (straight or branched), at least two of Rx ₁ to Rx ₃ are preferably methyl groups. Each of the above groups may have a substituent. Among them, Rx ₁ to Rx ₃ each independently preferably represent a straight or branched alkyl group, and Rx ₁ to Rx ₃ each independently more preferably represent a straight alkyl group. Two of Rx ₁ to Rx ₃ may be bonded to each other to form a ring (which may be monocyclic or polycyclic). As the alkyl group of Rx ₁ to Rx ₃ , alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl, are preferred. As the cycloalkyl group of Rx ₁ to Rx ₃ , monocyclic cycloalkyl groups, such as cyclopentyl and cyclohexyl, and polycyclic cycloalkyl groups, such as norbornyl, tetracyclodecyl, tetracyclododecyl and adamantyl, are preferred. As the aryl group of Rx ₁ to Rx ₃ , aryl groups having 6 to 10 carbon atoms are preferred, for example, phenyl, naphthyl and anthracenyl can be mentioned. As the aralkyl group of Rx ₁ to Rx ₃ , a group in which one hydrogen atom in the alkyl group of Rx ₁ to Rx ₃ is substituted by an aryl group (preferably a phenyl group) having 6 to 10 carbon atoms is preferred, and examples thereof include benzyl and the like. As the alkenyl group of Rx ₁ to Rx ₃ , a vinyl group is preferred. As the ring formed by two of Rx ₁ to Rx ₃ being bonded together, a cycloalkyl group is preferred. As the cycloalkyl group formed by two of Rx ₁ to Rx ₃ being bonded together, a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecyl group, a tetracyclododecyl group or an adamantyl group is preferred, and a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferred. In the cycloalkyl group formed by two of _Rx1 to _Rx3 being bonded, for example, one of the methylidene groups constituting the ring may be substituted by a heteroatom such as an oxygen atom, a group having a heteroatom such as a carbonyl group, or a vinylidene group. In addition, in such cycloalkyl groups, one or more of the ethylidene groups constituting the cycloalkane ring may be substituted by a vinylidene group. The group represented by formula (Y1) or formula (Y2) is preferably, for example, in which _Rx1 is a methyl group or an ethyl group, and _Rx2 and _Rx3 are bonded to form the above-mentioned cycloalkyl group.

In formula (Y3), R ₃₆ to R ₃₈ each independently represent a hydrogen atom or a monovalent organic group. R ₃₇ and R ₃₈ may be bonded to each other to form a ring. Examples of the monovalent organic group include alkyl, cycloalkyl, aryl, aralkyl and alkenyl groups. R ₃₆ is also preferably a hydrogen atom. In addition, the above-mentioned alkyl, cycloalkyl, aryl and aralkyl groups may contain heteroatoms such as oxygen atoms and/or groups having heteroatoms such as carbonyl groups. For example, in the above-mentioned alkyl, cycloalkyl, aryl and aralkyl groups, for example, one or more methyl groups may be substituted by heteroatoms such as oxygen atoms and/or groups having heteroatoms such as carbonyl groups. In addition, R ₃₈ may be bonded to each other with another substituent group possessed by the main chain of the repeating unit to form a ring. The group formed by R ₃₈ and another substituent of the main chain of the repeating unit bonding to each other is preferably an alkylene group such as a methylene group.

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

The repeating unit (iii) is preferably at least one repeating unit selected from the group consisting of a repeating unit represented by the following general formula (a-3) and a repeating unit represented by the following general formula (a-4).

[Chemical formula 11]

In the general formula (a-3), ^Ra5 and ^Ra15 each independently represent a hydrogen atom or an alkyl group. ^L3 represents a single bond or -C(=O)O-. r represents an integer from 0 to 2. s represents an integer from 0 to 4. ^Rp1 represents a group that is dissociated by the action of an acid. t represents an integer from 0 to 4. ^Rp2 represents a group that is dissociated by the action of an acid. At least one of s and t is an integer greater than 1. u represents an integer from 0 to (5+r×4-st). ^Ra6 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group, or a group composed of two or more of these. When u is 2 or more, a plurality of ^Ra6 groups may be the same or different, and may be bonded to each other to form a ring. Furthermore, ^Ra6 and ^Rp1 , ^Ra6 and ^Rp2 , and ^Rp1 and ^Rp2 may bond to each other to form a ring. The aromatic rings bonded to ^Ra15 and ^L3 may bond to each other to form a ring.

[Chemical formula 12]

In the general formula (a-4), R ^a7 represents a hydrogen atom or an alkyl group. R ^p3 represents a group that is released by the action of an acid.

(Repeating unit represented by general formula (a-3)) The alkyl group as R ^a5 may be any of a linear chain and a branched chain. The carbon number of the alkyl group is not particularly limited, and is preferably 1 to 5, and more preferably 1 to 3. The alkyl group may further have a substituent. r represents an integer from 0 to 2, preferably 0 or 1, and more preferably 0. The aromatic ring in the general formula (a-3) is benzene when r represents 0, naphthalene when r represents 1, and anthracene when r represents 2. s represents an integer from 0 to 4, preferably an integer from 0 to 2, and more preferably 0 or 1.

R ^p1 represents a group that is released by the action of an acid. The group that is released by the action of an acid is not particularly limited, and the groups represented by the above-mentioned formulas (Y1) to (Y4) can be cited. In the general formula (a-3), -OR ^p1 , R ^p1 is released by the action of an acid to generate a hydroxyl group. t represents an integer of 0 to 4, preferably an integer of 0 to 2, and more preferably 0 or 1. At least one of s and t is an integer greater than 1. R ^p2 represents a group that is released by the action of an acid. The group that is released by the action of an acid is not particularly limited, and the groups represented by the above-mentioned formulas (Y1) to (Y4) can be cited. In the general formula (a-3), -COOR ^p2 , R ^p1 is released by the action of an acid to generate a carboxyl group.

^Ra6 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group, or a group composed of two or more of these. As the halogen atom of ^Ra6 , for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom can be mentioned, preferably a fluorine atom or an iodine atom. As the alkyl group of ^Ra6 , it can be any one of a straight chain and a branched chain. The carbon number of the alkyl group is not particularly limited, preferably 1 to 10, more preferably 1 to 6. The methyl group contained in the alkyl group of ^Ra6 can be substituted by at least one of -CO- and -O-. The carbon number of the cycloalkyl group of ^Ra6 is not particularly limited, preferably 3 to 20, more preferably 5 to 15. The cycloalkyl group of R ^a4 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, and a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecyl group, a tetracyclododecyl group, and an adamantyl group. The alkyl group contained in the alkoxy group of R ^a6 may be either a linear or branched chain group. The carbon number of the alkyl group contained in the alkoxy group is not particularly limited, and is preferably 1 to 10, and more preferably 1 to 6. The carbon number of the aryl group contained in the aryloxy group of R ^a6 is not particularly limited, and is preferably 6 to 20, and more preferably 6 to 10. The aryl group contained in the aryloxy group of R ^a2 is preferably a phenyl group.

The alkyl group contained in the alkylthio group of R ^a6 may be any of a linear chain and a branched chain. The carbon number of the alkyl group contained in the alkylthio group is not particularly limited, and is preferably 1 to 10, and more preferably 1 to 6. The carbon number of the aryl group contained in the arylthio group of R ^a6 is not particularly limited, and is preferably 6 to 20, and more preferably 6 to 10. The aryl group contained in the arylthio group of R ^a2 is preferably a phenyl group. The carbon number of the aryl group of R ^a6 is not particularly limited, and is preferably 6 to 20, and more preferably 6 to 10. The aryl group of R ^a4 is preferably a phenyl group. The heteroaryl group of R ^a6 preferably contains at least one heteroatom selected from the group consisting of a sulfur atom, a nitrogen atom and an oxygen atom. The number of heteroatoms contained in the heteroaryl group is preferably 1 to 5, and more preferably 1 to 3. The number of carbon atoms in the heteroaryl group is not particularly limited, but is preferably 2 to 20, and more preferably 3 to 15. The heteroaryl group may be monocyclic or polycyclic. Examples of the heteroaryl group of R ^a4 include thienyl, furyl, benzothienyl, dibenzothienyl, benzofuranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, isothiazolyl, and thiadiazolyl.

The group consisting of two or more of these groups is not particularly limited, and examples thereof include a group consisting of at least one selected from the group consisting of an ester group, a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, and a carboxyl group.

The above-mentioned alkyl, cycloalkyl, alkoxy, aryloxy, alkylthio, arylthio, aryl, heteroaryl, ester, carboxyl, or a group composed of two or more of these groups may further have a substituent. When u is 2 or more, a plurality of ^Ra6 may be the same or different, and may be bonded to each other to form a ring. In addition, ^Ra6 and ^Rp1 , ^Ra6 and ^Rp2 , and ^Rp1 and ^Rp2 may be bonded to each other to form a ring. The ring formed by a plurality of ^Ra6s bonding to each other is not particularly limited, and may be a monocyclic ring or a polycyclic ring. The ring formed by ^Ra6 and ^Rp1 , ^Ra6 and ^Rp2 , and ^Rp1 and ^Rp2 bonding to each other is not particularly limited, and may be a monocyclic ring or a polycyclic ring.

(Repeating unit represented by general formula (a-4)) The alkyl group as R ^a7 may be any of a linear chain and a branched chain. The carbon number of the alkyl group is not particularly limited, and is preferably 1 to 5, and more preferably 1 to 3. The alkyl group may further have a substituent. R ^p3 represents a group that is released by the action of an acid. The group that is released by the action of an acid is not particularly limited, and the groups represented by the above-mentioned formulas (Y1) to (Y4) can be cited. -COOR ^p3 in the general formula (a-4), R ^p3 is released by the action of an acid and generates a carboxyl group.

Specific examples of repeating unit (iii) are shown below, but the present invention is not limited thereto. In the formula, Rx represents H, CH ₃ , CF ₃ or CH ₂ OH, and Rxa and Rxb each independently represent a linear or branched alkyl group having 1 to 5 carbon atoms. Z represents a substituent, and when there are plural substituents, each is independent. p represents 0 or a positive integer. In the formula, Xa ₁ represents H, CH ₃ , CF ₃ or CH ₂ OH, and Rxa and Rxb each independently represent a linear or branched alkyl group having 1 to 5 carbon atoms.

[Chemical formula 13]

[Chemical formula 14]

[Chemical formula 15]

[Chemical formula 16]

[Chemical formula 17]

[Chemical formula 18]

[Chemical formula 19]

[Chemical formula 20]

[Chemical formula 21]

[Chemical formula 22]

[Chemical formula 23]

[Chemical formula 24]

[Chemical formula 25]

[Chemical formula 26]

The repeating unit (iii) does not have a phenolic hydroxyl group. The repeating unit (iii) is preferably a repeating unit represented by the above general formula (a-3).

The content of the repeating unit (iii) is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 15 mol% or more, based on all the repeating units in the resin (A). Furthermore, the content of the repeating unit (iii) is preferably 70 mol% or less, more preferably 60 mol% or less, and further preferably 50 mol% or less, based on all the repeating units in the resin (A).

The repeating unit (iii) contained in the resin (A) may be one kind or two or more kinds. When two or more kinds are contained, it is preferred that the total content thereof is within the above-mentioned preferred content range.

Resin (A) is a resin having repeating units (i), repeating units (ii) and repeating units (iii). As a preferred embodiment, the total content of repeating units (i), repeating units (ii) and repeating units (iii) is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more relative to all repeating units in resin (A). In addition, as a preferred embodiment, resin (A) may only have repeating units (i), repeating units (ii) and repeating units (iii).

(Other repeating units) In addition to the repeating unit (i), the repeating unit (ii) and the repeating unit (iii), the resin (A) may also have other repeating units. Other repeating units are described below.

(Repeating unit with polar group) The repeating unit with polar group is a repeating unit different from the repeating unit (i), the repeating unit (ii) and the repeating unit (iii). As the polar group of the repeating unit with polar group, for example, there can be mentioned a hydroxyl group, a lactone group, a sultone group, a lactamide group, an imide group, an amide group, a sulfonamide group, a carbonate group, a carbamate group, a urea group, a nitrile group, a sulfonyl group and the like. The polar group may be an acid group. As the polar group, a hydroxyl group or a lactone group is preferred, an aromatic hydroxyl group is more preferred, and a phenolic hydroxyl group is further preferred. As a repeating unit containing a polar group, a repeating unit represented by the following general formula (S3) is preferred.

The repeating unit having a polar group is preferably a repeating unit represented by the following general formula (S3).

[Chemical formula 27]

In the general formula (S3), _R101 , _R102 and _R103 independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. _R102 may be bonded to ^ArA to form a ring, in which case _R102 represents a single bond or an alkylene group. _LA represents a single bond or a divalent linking group. _ArA represents an aromatic cyclic group. k represents an integer of 1 to 5.

In the general formula (S3), R ₁₀₁ , R ₁₀₂ and R ₁₀₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. The description, specific examples and preferred ranges of R ₁₀₁ , R ₁₀₂ and R ₁₀₃ are the same as the description, specific examples and preferred ranges of Ra ₁ to Ra ₃ in the general formula (S1).

Ar _A in the general formula (S3) represents an aromatic cyclic group, and more specifically, represents a (k+1)-valent aromatic cyclic group. The divalent aromatic cyclic group when k is 1 is preferably, for example, an aryl group having 6 to 18 carbon atoms such as phenylene, tolylene, naphthyl, anthracene, or a thiophene ring, furan ring, pyrrole ring, benzothiophene ring, benzofuran ring, benzopyrrole ring, triazine ring, imidazole ring, benzimidazole ring, triazole ring, thiadiazole ring, thiazole ring, or a heterocyclic divalent aromatic cyclic group. The above aromatic cyclic group may have a substituent. As a specific example of a (k+1)-valent aromatic ring group when k is an integer greater than or equal to 2, there can be cited a group formed by removing any (k-1) hydrogen atoms from the above-mentioned specific examples of a divalent aromatic ring group. The (k+1)-valent aromatic ring group may further have a substituent. The substituent that the (k+1)-valent aromatic ring group may have is not particularly limited, and examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, hexyl, 2-ethylhexyl, octyl, and dodecyl; alkoxy groups such as methoxy, ethoxy, hydroxyethoxy, propoxy, hydroxypropoxy, and butoxy; aryl groups such as phenyl; hydroxyl groups, etc. A plurality of substituents may be bonded to form a ring. Ar _A is preferably an aromatic ring group having 6 to 18 carbon atoms, more preferably a benzene ring group, a naphthyl ring group or a biphenyl ring group.

_LA in the general formula (S3) represents a single bond or a divalent linking group. The divalent linking group represented by _LA is not particularly limited, and examples thereof include -COO-, -CONR ₆₄ -, an alkylene group, or a group formed by combining two or more of these groups. The above-mentioned R ₆₄ represents a hydrogen atom or an alkyl group. The above-mentioned alkylene group is not particularly limited, and preferably includes an alkylene group having 1 to 8 carbon atoms, such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, and an octyl group. When R ₆₄ represents an alkyl group, examples thereof include an alkyl group having 20 or less carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, and a dodecyl group, and preferably includes an alkyl group having 8 or less carbon atoms.

The repeating unit represented by the general formula (S3) preferably has a hydroxystyrene structure. That is, Ar _A preferably represents a benzene ring group. k preferably represents an integer of 1 to 3, and more preferably represents 1 or 2.

Specific examples of repeating units having acid-degradable groups are shown below, but are not limited thereto. When the repeating unit having a polar group has a phenolic hydroxyl group, the ClogP value of the anionic state after the hydrogen atom of the phenolic hydroxyl group is dissociated in the monomer corresponding to the repeating unit is also shown. The ClogP value is measured by the above method.

[Chemical formula 28]

The content of the repeating unit having a polar group in the resin (A) is not particularly limited, but is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 15 mol% or more, relative to all the repeating units in the resin (A). Furthermore, the content of the repeating unit having a polar group is preferably 30 mol% or less, more preferably 25 mol% or less, and further preferably 20 mol% or less, relative to all the repeating units in the resin (A).

The resin (A) may contain one or more types of repeating units having a polar group. When the resin (A) contains two or more types, the total content thereof is preferably within the above-mentioned preferred content range.

(Repeating unit having an acid-degradable group) The resin (A) may contain a repeating unit having an acid-degradable group as another repeating unit. The repeating unit having an acid-degradable group is a repeating unit different from the repeating unit (i), the repeating unit (ii) and the repeating unit (iii).

(Repeating units having lactone groups, sultone groups or carbonate groups) The resin (A) may have a repeating unit containing at least one selected from the group consisting of lactone groups, sultone groups and carbonate groups (hereinafter, also referred to as "unit Y"). Unit Y also preferably does not have an acid group such as a hydroxyl group and a hexafluoropropanol group.

As a lactone group or a sultone group, it is sufficient as long as it has a lactone structure or a sultone structure. The lactone structure or the sultone structure is preferably a 5-7-membered ring lactone structure or a 5-7-membered ring sultone structure. Among them, it is more preferred that another ring structure is condensed on the 5-7-membered ring lactone structure in the form of a bicyclic structure or a spirocyclic structure, or another ring structure is condensed on the 5-7-membered ring sultone structure in the form of a bicyclic structure or a spirocyclic structure. Regarding the resin (A), the contents of [0120] to [0134] of International Publication No. 2022/024928 can be incorporated as a reference.

(Repeating units having neither an acid-decomposable group nor an acid group, but having a fluorine atom, a bromine atom, or an iodine atom) In addition to the above-mentioned repeating units, the resin (A) may also have repeating units having neither an acid-decomposable group nor an acid group, but having a fluorine atom, a bromine atom, or an iodine atom (hereinafter, also referred to as unit X). The <repeating units having neither an acid-decomposable group nor an acid group, but having a fluorine atom, a bromine atom, or an iodine atom> mentioned here is preferably different from the <repeating units having a lactone group, a sultone group, or a carbonate group> and the <repeating units having a photoacid generating group> described later.

As the unit X, a repeating unit represented by formula (C) is preferred.

[Chemical formula 29]

_L5 represents a single bond or an ester group. _R9 represents a hydrogen atom, or an alkyl group which may have a fluorine atom or an iodine atom. _R10 represents a hydrogen atom, an alkyl group which may have a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, an aryl group which may have a fluorine atom or an iodine atom, or a group composed of these.

Hereinafter, repeating units having fluorine atoms or iodine atoms are exemplified.

[Chemical formula 30]

The content of the unit X is preferably 0 mol% or more, more preferably 5 mol% or more, and further preferably 10 mol% or more, relative to all the repeating units in the resin (A). The upper limit thereof is preferably 50 mol% or less, more preferably 45 mol% or less, and further preferably 40 mol% or less, relative to all the repeating units in the resin (A).

In the repeating units of the resin (A), the total content of the repeating units containing at least one of the fluorine atom, the bromine atom and the iodine atom 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 relative to all the repeating units of the resin (A). The upper limit is not particularly limited, for example, it is 100 mol% or less relative to all the repeating units of the resin (A). In addition, as the repeating units containing at least one of the fluorine atom, the bromine atom and the iodine atom, for example, there can be cited: a repeating unit having a fluorine atom, a bromine atom or an iodine atom and having an acid-decomposable group; a repeating unit having a fluorine atom, a bromine atom or an iodine atom and having an acid group; and a repeating unit having a fluorine atom, a bromine atom or an iodine atom.

(Repeating unit having a photoacid generating group) As a repeating unit other than the above, the resin (A) may have a repeating unit containing a group that generates an acid by irradiation with actinic rays or radiation (preferably electron beams or extreme ultraviolet rays) (hereinafter, also referred to as a "photoacid generating group"). As a repeating unit containing a photoacid generating group, a repeating unit represented by formula (4) can be cited.

[Chemical formula 31]

R ⁴¹ represents a hydrogen atom or a methyl group. ^{L 41} represents a single bond or a divalent linking group. L ⁴² represents a divalent linking group. R ⁴⁰ represents a structural site that generates an acid in the side chain by decomposition upon irradiation with actinic rays or radiation. The following examples illustrate repeating units having a photoacid generating group, but are not limited thereto.

[Chemical formula 32]

[Chemical formula 33]

In addition, as a repeating unit represented by formula (4), for example, there can be cited the repeating unit described in paragraphs [0094] to [0105] of Japanese Patent Application Publication No. 2014-041327 and the repeating unit described in paragraph [0094] of International Publication No. 2018/193954.

When the resin (A) contains a repeating unit having a photoacid generating group, the content of the repeating unit having a photoacid generating group is preferably 1 mol% or more, more preferably 5 mol% or more, relative to all the repeating units in the resin (A). Moreover, as an upper limit, it is preferably 40 mol% or less, more preferably 35 mol% or less, and further preferably 30 mol% or less, relative to all the repeating units in the resin (A).

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

[Chemical formula 34]

In the formula, R ₆ and R ₇ independently represent a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amine group, a halogen atom, an ester group (-OCOR or -COOR: R is an alkyl group or a fluorinated alkyl group having 1 to 6 carbon atoms), or a carboxyl group. As the alkyl group, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms is preferred. n ₃ represents an integer from 0 to 6. n ₄ represents an integer from 0 to 4. X ₄ is a methyl group, an oxygen atom or a sulfur atom. The following is an example of a repeating unit represented by formula (V-1) or (V-2). As a repeating unit represented by formula (V-1) or (V-2), for example, the repeating unit described in paragraph [0100] of International Publication No. 2018/193954 can be cited.

(Repeating unit for reducing the mobility of the main chain) From the perspective of being able to suppress excessive diffusion of the generated acid or pattern collapse during development, the resin (A) preferably has a higher glass transition temperature (Tg). Tg is preferably greater than 90°C, more preferably greater than 100°C, further preferably greater than 110°C, and particularly preferably greater than 125°C. In addition, from the perspective of having a good dissolution rate in the developer, Tg is preferably 400°C or less, more preferably 350°C or less. In addition, in this specification, the glass transition temperature (Tg) of a polymer such as resin (A) (hereinafter "Tg of the repeating unit") is calculated by the following method. First, the Tg of the homopolymer consisting only of each repeating unit contained in the polymer is calculated separately by the Bicerano method. Next, the mass ratio (%) of each repeating unit relative to all repeating units in the polymer is calculated. Next, the Tg at each mass ratio is calculated using Fox's formula (described in Materials Letters 62 (2008) 3152, etc.), and the sum is taken as the Tg (°C) of the polymer. The Bicerano method is described in Prediction of polymer properties, Marcel Dekker Inc, New York (1993). When calculating Tg using the Bicerano method, the polymer physical property evaluation software MDL Polymer (MDL Information Systems, Inc.) can be used for calculation.

In order to increase the Tg of the resin (A) (preferably, to make the Tg exceed 90°C), it is preferred to reduce the mobility of the main chain of the resin (A). The following methods (a) to (e) can be cited as methods for reducing the mobility of the main chain of the resin (A). (a) Introducing a large-volume substituent into the main chain (b) Introducing a plurality of substituents into the main chain (c) Introducing a substituent that induces interaction between resins (A) near the main chain (d) Forming the main chain in a ring structure (e) Connecting a ring structure to the main chain In addition, the resin (A) preferably has a repeating unit whose homopolymer Tg shows 130°C or above. In addition, the type of repeating unit showing a homopolymer Tg of 130°C or more is not particularly limited, as long as it is a repeating unit whose homopolymer Tg calculated by the Bicerano method is 130°C or more. In addition, the repeating units represented by the formula (A) to (E) described later are equivalent to the repeating units whose homopolymer Tg is 130°C or more, depending on the type of functional groups therein.

As an example of a specific method for realizing the above (a), there can be cited a method of introducing a repeating unit represented by the formula (A) into the resin (A).

[Chemical formula 35]

In formula (A), _RA represents a group containing a polycyclic structure. _RX represents a hydrogen atom, a methyl group, or an ethyl group. The group containing a polycyclic structure is a group containing a plurality of ring structures, and the plurality of ring structures may be fused or not fused. As specific examples of the repeating unit represented by formula (A), the repeating units described in paragraphs [0107] to [0119] of International Publication No. 2018/193954 can be cited.

As an example of a specific method for realizing the above (b), there can be cited a method of introducing a repeating unit represented by the formula (B) into the resin (A).

[Chemical formula 36]

In formula (B), R _b1 to R _b4 each independently represent a hydrogen atom or an organic group, and at least two of R _b1 to R _b4 represent an organic group. When at least one of the organic groups is a group in which the ring structure is directly linked to the main chain in the repeating unit, there is no particular restriction on the type of the other organic groups. In addition, when any of the organic groups is not a group in which the ring structure is directly linked to the main chain in the repeating unit, at least two of the organic groups are substituents having three or more constituent atoms other than hydrogen atoms. As specific examples of the repeating unit represented by formula (B), the repeating units described in paragraphs [0113] to [0115] of International Publication No. 2018/193954 can be cited.

As an example of a specific method for realizing the above (c), there can be cited a method of introducing a repeating unit represented by the formula (C) into the resin (A).

[Chemical formula 37]

In formula (C), R _c1 to R _c4 each independently represent a hydrogen atom or an organic group, and at least one of R _c1 to R _c4 is a group containing a hydrogen atom with hydrogen bonding capability within 3 atoms from the main chain carbon. Among them, in terms of the interaction between the main chains of the inducing resin (A), a hydrogen atom with hydrogen bonding capability within 2 atoms (closer to the main chain side) is preferred. As specific examples of the repeating unit represented by formula (C), the repeating units described in paragraphs [0119] to [0121] of International Publication No. 2018/193954 can be cited.

As an example of a specific method for realizing the above-mentioned (d), there can be cited a method of introducing a repeating unit represented by the formula (D) into the resin (A).

[Chemical formula 38]

In formula (D), "Cyclic" represents a group that forms a main chain with a cyclic structure. The number of atoms constituting the ring is not particularly limited. As specific examples of the repeating unit represented by formula (D), the repeating units described in paragraphs [0126] to [0127] of International Publication No. 2018/193954 can be cited.

As an example of a specific method for realizing the above (e), there can be cited a method of introducing a repeating unit represented by the formula (E) into the resin (A).

[Chemical formula 39]

In formula (E), Re each independently represents a hydrogen atom or an organic group. As an organic group, for example, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group which may have a substituent can be cited. "Cyclic" is a cyclic group containing carbon atoms in the main chain. The number of atoms contained in the cyclic group is not particularly limited. As a specific example of the repeating unit represented by formula (E), the repeating units described in paragraphs [0131] to [0133] of International Publication No. 2018/193954 can be cited.

(Repeating units having at least one group selected from lactone group, sultone group, carbonate group, hydroxyl group, cyano group and alkali-soluble group) The resin (A) may have a repeating unit having at least one group selected from lactone group, sultone group, carbonate group, hydroxyl group, cyano group and alkali-soluble group. As the repeating unit having lactone group, sultone group or carbonate group possessed by the resin (A), the repeating unit described in the above-mentioned <Repeating unit containing lactone group, sultone group or carbonate group> can be cited. The preferred content is also the content described in the above-mentioned <Repeating unit containing lactone group, sultone group or carbonate group>.

The resin (A) may have a repeating unit containing a hydroxyl group or a cyano group. This can improve substrate adhesion and developer affinity. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The repeating unit having a hydroxyl group or a cyano group is preferably one having no acid-decomposable group. As repeating units having a hydroxyl group or a cyano group, the repeating units described in paragraphs [0081] to [0084] of Japanese Patent Publication No. 2014-098921 can be cited.

The resin (A) may have a repeating unit containing an alkali-soluble group. As the alkali-soluble group, carboxyl group, sulfonamide group, sulfonimide group, disulfonimide group, and aliphatic alcohol group substituted with an electron-withdrawing group at the α position (e.g., hexafluoroisopropanol group) can be cited, and carboxyl group is preferred. By including a repeating unit having an alkali-soluble group in the resin (A), the resolution in the contact hole application can be increased. As the repeating unit having an alkali-soluble group, the repeating units described in paragraphs [0085] and [0086] of Japanese Patent Publication No. 2014-098921 can be cited.

(Repeating units having an alicyclic hydrocarbon structure and not showing acid decomposition) The resin (A) may have a repeating unit containing an alicyclic hydrocarbon structure and not showing acid decomposition. This can reduce the dissolution of low molecular weight components from the photoresist film into the immersion solution during immersion exposure. Examples of the repeating unit having an alicyclic hydrocarbon structure and not showing acid decomposition include repeating units derived from 1-adamantyl (meth)acrylate, diadamantyl (meth)acrylate, tricyclodecyl (meth)acrylate, or cyclohexyl (meth)acrylate.

(Repeating units represented by formula (III) without either hydroxyl group or cyano group) The resin (A) may have a repeating unit represented by formula (III) without either hydroxyl group or cyano group.

[Chemical formula 40]

In the formula (III), R ₅ represents a alkyl group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group. Ra represents a hydrogen atom, an alkyl group, or a -CH ₂ -O-Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group, or an acyl group. As the repeating unit represented by the formula (III) having neither a hydroxyl group nor a cyano group, the repeating units described in paragraphs [0087] to [0094] of Japanese Patent Application Laid-Open No. 2014-098921 can be cited.

In addition to the above-mentioned repetitive structural units, the resin (A) may also have various repetitive structural units in order to adjust dry etching resistance, compatibility with standard developer, substrate adhesion, photoresist profile, resolution, heat resistance, and sensitivity.

As resin (A), in particular, when the composition of the present invention is used as an ArF photosensitive or radiation-sensitive resin composition, it is preferred that all repeating units are composed of repeating units derived from a compound having an ethylenically unsaturated bond. In particular, it is also preferred that all repeating units are composed of (meth)acrylate repeating units. When all repeating units are composed of (meth)acrylate repeating units, any one of a methacrylate repeating unit, an acrylate repeating unit, and a methacrylate repeating unit and an acrylate repeating unit can be used, and it is preferred that the acrylate repeating unit is less than 50 mol% of all repeating units.

The resin (A) can be synthesized by conventional methods (e.g., free radical polymerization). The weight average molecular weight (Mw) of the resin (A) is preferably 30,000 or less, more preferably 1,000 to 30,000, further preferably 3,000 to 30,000, and particularly preferably 5,000 to 15,000, as a polystyrene conversion value according to the GPC method. The dispersion (molecular weight distribution, Pd, Mw/Mn) of the resin (A) is preferably 1 to 5, more preferably 1 to 3, further preferably 1.2 to 3.0, and particularly preferably 1.2 to 2.0. The smaller the dispersion, the better the resolution and photoresist shape, and the smoother the sidewall of the photoresist pattern, the better the roughness.

In the composition of the present invention, the content of the resin (A) is preferably 40.0 to 99.9% by mass, and more preferably 60.0 to 90.0% by mass, relative to the total solid content of the composition of the present invention. One type of resin (A) may be used, or two or more types may be used. When two or more types are used, it is preferred that the total content thereof is within the above-mentioned preferred content range.

[Compounds (B) that generate acid by irradiation with actinic rays or radiation] The composition of the present invention preferably contains a compound (photoacid generator) that generates acid by irradiation with actinic rays or radiation. The photoacid generator may be in the form of a low molecular weight compound or in the form of being incorporated into a part of a polymer. In addition, the form of a low molecular weight compound and the form of being incorporated into a part of a polymer may be used in combination. When the photoacid generator is in the form of a low molecular weight compound, the molecular weight of the photoacid generator is preferably 3000 or less, more preferably 2000 or less, and further preferably 1000 or less. The lower limit is not particularly limited, but is preferably 100 or more. When the photoacid generator is in the form of being incorporated into a part of the polymer, it can be incorporated into a part of the resin (A) or into a resin different from the resin (A). The photoacid generator is preferably in the form of a low molecular weight compound. The photoacid generator is preferably a compound that generates an acid with a pKa of -2.0 or more by irradiation with actinic rays or radiation, and is more preferably a compound that generates an acid with a pKa of -2.0 or more and 1.0 or less.

As the photoacid generator, for example, a compound represented by "M ⁺ X ^- " (onium salt) can be cited, and preferably a compound that generates an organic acid by exposure. As the above-mentioned organic acid, for example, sulfonic acid (aliphatic sulfonic acid, aromatic sulfonic acid, camphorsulfonic acid, etc.), carboxylic acid (aliphatic carboxylic acid, aromatic carboxylic acid, aralkyl carboxylic acid, etc.), carbonylsulfonylimidic acid, bis(alkylsulfonyl)imidic acid, and tris(alkylsulfonyl)methyl acid can be cited.

In the compound represented by "M ⁺ X ^- ", M ⁺ represents an organic cation. There is no particular limitation on the organic cation. The valence of the organic cation may be monovalent or divalent or more. Among them, the organic cation is preferably a cation represented by formula (ZaI) (hereinafter also referred to as "cation (ZaI)") or a cation represented by formula (ZaII) (hereinafter also referred to as "cation (ZaII)").

[Chemical formula 41]

In the above formula (ZaI), R ²⁰¹ , R ²⁰² and R ²⁰³ each independently represent an organic group. The carbon number of the organic group of R ²⁰¹ , R ²⁰² and R ²⁰³ is preferably 1 to 30, more preferably 1 to 20. Two of R ²⁰¹ to R ²⁰³ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group or a carbonyl group. Examples of the group formed by two of R ²⁰¹ to R ²⁰³ bonding include an alkylene group (e.g., a butylene group and a pentylene group) and -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -.

Preferred embodiments of the organic cation in formula (ZaI) include cation (ZaI-1), cation (ZaI-2), cation (ZaI-3b), and cation (ZaI-4b) described later.

First, the cation (ZaI-1) will be described. The cation (ZaI-1) is an aryl zirconia cation, wherein at least one of R ²⁰¹ to R ²⁰³ in the above formula (ZaI) is an aryl zirconia cation. The aryl zirconia cation may be a cation in which all of R ²⁰¹ to R ²⁰³ are aryl groups, or a part of R ²⁰¹ to R ²⁰³ are aryl groups and the rest are alkyl groups or cycloalkyl groups. One of R ²⁰¹ to R ²⁰³ may be an aryl group, the remaining two of R ²⁰¹ to R ²⁰³ may be bonded to form a ring structure, or an oxygen atom, a sulfur atom, an ester group, an amide group or a carbonyl group may be contained in the ring. Examples of the group formed by two of R ²⁰¹ to R ²⁰³ being bonded include alkylene groups (e.g., butylene, pentylene, and -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -), wherein one or more methylene groups may be substituted by an oxygen atom, a sulfur atom, an ester group, an amide group, and/or a carbonyl group. Examples of the aryl zirconia cation include triaryl zirconia cations, diaryl alkyl zirconia cations, aryl dialkyl zirconia cations, diaryl cycloalkyl zirconia cations, and aryl dicycloalkyl zirconia cations.

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

As the substituent that the aryl group, alkyl group and cycloalkyl group represented by R ²⁰¹ to R ²⁰³ may have, preferably an alkyl group (e.g., having 1 to 15 carbon atoms), a cycloalkyl group (e.g., having 3 to 15 carbon atoms), an aryl group (e.g., having 6 to 14 carbon atoms), an alkoxy group (e.g., having 1 to 15 carbon atoms), a cycloalkylalkoxy group (e.g., having 1 to 15 carbon atoms), a halogen atom (e.g., fluorine and iodine), a hydroxyl group, a carboxyl group, an ester group, a sulfinyl group, a sulfonyl group, an alkylthio group, or a phenylthio group. The above substituents may further have substituents if possible, and the above alkyl group may have a halogen atom as a substituent and may be a halogenated alkyl group such as a trifluoromethyl group. The above substituents may also preferably form an acid-decomposable group by any combination. The acid-degradable group refers to a group that decomposes by the action of an acid to generate a polar group, and preferably a structure in which the polar group is protected by a group that is dissociated by the action of an acid. The polar group and the dissociating group are as described above.

Next, the cation (ZaI-2) will be described. The cation (ZaI-2) is a cation in which R ²⁰¹ to R ²⁰³ in the formula (ZaI) each independently represent an organic group having no aromatic ring. The aromatic ring also includes an aromatic ring containing a heteroatom. The carbon number of the organic group having no aromatic ring as R ²⁰¹ to R ²⁰³ is preferably 1 to 30, and more preferably 1 to 20. R ²⁰¹ to R ²⁰³ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group or an alkoxycarbonylmethyl group, and further preferably a linear or branched 2-oxoalkyl group.

Examples of the alkyl and cycloalkyl groups of R ²⁰¹ to R ²⁰³ include linear alkyl groups with 1 to 10 carbon atoms or branched alkyl groups with 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl), and cycloalkyl groups with 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl). R ²⁰¹ to R ²⁰³ may be further substituted with a halogen atom, an alkoxy group (e.g., with 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. The substituents of R ²⁰¹ to R ²⁰³ are each independently or preferably formed into an acid-decomposable group by any combination of substituents.

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

[Chemical formula 42]

In formula (ZaI-3b), _R1c to _R5c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group. _R6c and _R7c each independently represent a hydrogen atom, an alkyl group (e.g., tert-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group. _Rx and _Ry each independently represent an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group. The substituents of _R1c to _R7c , and _Rx and _Ry each independently form an acid-decomposable group by any combination of substituents.

Any two or more of R _1c to R _5c , R _5c and R _6c , R _6c and R _7c , R _5c and R _x , and R _x and R _y may be bonded to each other to form a ring, and the ring may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the above-mentioned ring include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterocyclic rings, and polycyclic condensed rings formed by combining two or more of these rings. Examples of the ring include 3-10 membered rings, preferably 4-8 membered rings, and more preferably 5- or 6-membered rings.

As the group formed by the bonding of any two or more of R _1c to R _5c , R _6c and R _7c , and R _x and R _y , there can be mentioned alkylene groups such as butylene and pentylene. The methylene group in the alkylene group may be substituted by a heteroatom such as an oxygen atom. As the group formed by the bonding of R _5c and R _6c , and R _5c and R _x , it is preferably a single bond or an alkylene group. As the alkylene group, there can be mentioned methylene and ethylene.

R _1c to R _5c , R _6c , R _7c , R _x , R _y , and the ring formed by any two or more of R _1c to R _5c , R _5c and R _6c , R _6c and R _7c , R _5c and R _x , and R _x and R _y bonding to each other may have a substituent.

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

[Chemical formula 43]

In formula (ZaI-4b), l represents an integer of 0 to 2, and r represents an integer of 0 to 8. R ₁₃ represents a hydrogen atom, a halogen atom (for example, a fluorine atom and an iodine atom), a hydroxyl group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a group containing a cycloalkyl group (which may be a cycloalkyl group itself or a group partially containing a cycloalkyl group). These groups may have a substituent. R ₁₄ represents a hydroxyl group, a halogen atom (for example, a fluorine atom and an iodine atom), an alkyl group, a halogenated alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group containing a cycloalkyl group (which may be a cycloalkyl group itself or a group partially containing a cycloalkyl group). These groups may have a substituent. When there are plural R ₁₄ , each independently represents the above-mentioned groups such as a hydroxyl group. R ₁₅ independently represents an alkyl group, a cycloalkyl group or a naphthyl group. Two R _{15 groups} may be bonded to each other to form a ring. When two R ₁₅ groups are bonded to each other to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom. In one embodiment, it is preferred that two R ₁₅ groups are alkylene groups and are bonded to each other to form a ring structure. In addition, the above-mentioned alkyl group, the above-mentioned cycloalkyl group and the above-mentioned naphthyl group, and the ring formed by two R ₁₅ groups being bonded to each other may have a substituent.

In formula (ZaI-4b), the alkyl groups of R ₁₃ , R ₁₄ and R ₁₅ may be linear or branched. The carbon number of the alkyl group is preferably 1 to 10. The alkyl group is preferably methyl, ethyl, n-butyl or t-butyl. Each substituent of R ₁₃ to R ₁₅ , and R _x and R _y is independently or preferably formed into an acid-decomposable group by any combination of substituents.

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

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

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

[Chemical formula 44]

[Chemical formula 45]

[Chemical formula 46]

In the compound represented by "M ⁺ X ^- ", X ^- represents an organic anion. The organic anion is not particularly limited, and monovalent or divalent or higher organic anions can be cited. The organic anion is preferably an anion having extremely low ability to cause a nucleophilic reaction, and more preferably a non-nucleophilic anion.

Examples of the non-nucleophilic anion include sulfonic acid anions (aliphatic sulfonic acid anions, aromatic sulfonic acid anions, camphorsulfonic acid anions, etc.), carboxylic acid anions (aliphatic carboxylic acid anions, aromatic carboxylic acid anions, aralkyl carboxylic acid anions, etc.), sulfonimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

The aliphatic part in the aliphatic sulfonic acid anion and the aliphatic carboxylic acid anion may be a linear or branched alkyl group, or a cycloalkyl group, preferably a linear or branched alkyl group with 1 to 30 carbon atoms, or a cycloalkyl group with 3 to 30 carbon atoms. The above-mentioned alkyl group may be, for example, a fluoroalkyl group (which may have a substituent other than a fluorine atom. It may also be a perfluoroalkyl group).

The aryl group in the aromatic sulfonic acid anion and the aromatic carboxylic acid anion is preferably an aryl group having 6 to 14 carbon atoms, for example, a phenyl group, a tolyl group, and a naphthyl group.

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

As the aralkyl group in the aralkyl carboxylic acid anion, an aralkyl group having 7 to 14 carbon atoms is preferred. As the aralkyl group having 7 to 14 carbon atoms, for example, benzyl, phenethyl, naphthylmethyl, naphthylethyl, and naphthylbutyl can be cited.

As the sulfonimide anion, for example, saccharin anion can be mentioned.

As the alkyl group in the bis(alkylsulfonyl)imide anion and the tris(alkylsulfonyl)methide anion, an alkyl group having 1 to 5 carbon atoms is preferred. As the substituent of such alkyl groups, halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkoxysulfonyl groups, aryloxysulfonyl groups, and cycloalkylaryloxysulfonyl groups can be cited, and fluorine atoms or alkyl groups substituted with fluorine atoms are preferred. In addition, the alkyl groups in the bis(alkylsulfonyl)imide anion can also bond with each other to form a ring structure. Thereby, the acid strength can be increased.

As other non-nucleophilic anions, for example, phosphorus fluoride (eg, PF ₆ ⁻ ), boron fluoride (eg, BF ₄ ⁻ ), and antimony fluoride (eg, SbF ₆ ⁻ ) can be cited.

As the non-nucleophilic anion, an aliphatic sulfonic acid anion in which at least the α-position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonic acid anion substituted with a fluorine atom or a group having a fluorine atom, a bis(alkylsulfonyl)imide anion in which the alkyl group is substituted with a fluorine atom, or a tris(alkylsulfonyl)methide anion in which the alkyl group is substituted with a fluorine atom is preferred. Among them, a perfluoroaliphatic sulfonic acid anion (preferably having 4 to 8 carbon atoms) or a benzenesulfonic acid anion having a fluorine atom is more preferred, and a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, a pentafluorobenzenesulfonic acid anion, or a 3,5-bis(trifluoromethyl)benzenesulfonic acid anion is further preferred.

As the non-nucleophilic anion, an anion represented by the following formula (AN1) is also preferred.

[Chemical formula 47]

In formula (AN1), ^R1 and ^R2 each independently represent a hydrogen atom or a substituent. The substituent is not particularly limited, and is preferably a non-electron-pulling group. Examples of the non-electron-pulling group include alkyl, hydroxyl, oxoalkyl, oxycarbonylalkyl, amino, alkyl-substituted amino, and alkyl-substituted amide. The non-electron-pulling group is each independently preferably -R', -OH, -OR', -OCOR', _-NH2 , _-NR'2 , -NHR', or -NHCOR'. R' is a monovalent alkyl group.

As the monovalent alkyl group represented by the above R', for example, there can be mentioned alkyl groups such as methyl, ethyl, propyl, and butyl; alkenyl groups such as vinyl, propenyl, and butenyl; monovalent linear or branched alkyl groups such as alkynyl such as ethynyl, propynyl, and butynyl; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl; monovalent alicyclic alkyl groups such as cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and norbornyl; aryl groups such as phenyl, tolyl, xylyl, mesityl, naphthyl, methylnaphthyl, anthracenyl, and methylanthryl; and monovalent aromatic alkyl groups such as aralkyl groups such as benzyl, phenethyl, phenylpropyl, naphthylmethyl, and anthracenylmethyl. Wherein, R ¹ and R ² are each independently preferably an alkyl group (preferably a cycloalkyl group) or a hydrogen atom.

L represents a divalent linking group. When there are plural Ls, Ls may be the same or different. Examples of the divalent linking group include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -S-, -SO-, -SO ₂ -, alkylene (preferably having 1 to 6 carbon atoms), cycloalkylene (preferably having 3 to 15 carbon atoms), alkenylene (preferably having 2 to 6 carbon atoms), and divalent linking groups formed by combining plural of these groups. Among them, the divalent linking group is preferably -O-CO-O-, -COO-, -CONH-, -CO-, -O-, -SO ₂ -, -O-CO-O-alkylene-, -COO-alkylene-, or -CONH-alkylene-, and more preferably -O-CO-O-, -O-CO-O-alkylene-, -COO-, -CONH-, -SO ₂ -, or -COO-alkylene-.

As L, for example, a group represented by the following formula ( _AN1-1 ) is preferred. * ^a- ( ^CR2a2 ) _X - _Q- ( ^CR2b2 ) _Y- * ^b (AN1-1)

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

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

Among them, ^R3 is preferably an organic group having a cyclic structure. The above-mentioned cyclic structure may be monocyclic or polycyclic, and may also have a substituent. The ring in the organic group containing the cyclic structure is preferably directly bonded to L in formula (AN1). The organic group having the above-mentioned cyclic structure may, for example, have heteroatoms (oxygen atoms, sulfur atoms and/or nitrogen atoms, etc.), or may not have heteroatoms. The heteroatoms may replace one or more carbon atoms forming the cyclic structure. The organic group having the above-mentioned cyclic structure is, for example, preferably a cyclic alkyl group, a lactone ring group, and a sultone ring group. Among them, the organic group having the above-mentioned cyclic structure is preferably a cyclic alkyl group. The alkyl group of the cyclic structure is preferably a monocyclic or polycyclic cycloalkyl group. Such groups may have a substituent. The cycloalkyl group may be a monocyclic group (cyclohexyl group, etc.) or a polycyclic group (adamantyl group, etc.), and the number of carbon atoms is preferably 5 to 12. As the lactone group and the sultone group, for example, in any of the structures represented by the above formulae (LC1-1) to (LC1-21) and the structures represented by the formulae (SL1-1) to (SL1-3), it is preferably a group formed by removing one hydrogen atom from a ring member atom constituting the lactone structure or the sultone structure.

The non-nucleophilic anion may be a benzenesulfonic acid anion, preferably a benzenesulfonic acid anion substituted with a branched alkyl group or a cycloalkyl group.

As the non-nucleophilic anion, an anion represented by the following formula (AN2) is also preferred.

[Chemical formula 48]

In formula (AN2), o represents an integer from 1 to 3. p represents an integer from 0 to 10. q represents an integer from 0 to 10.

Xf represents a hydrogen atom, a fluorine atom, an alkyl group substituted with at least one fluorine atom, or an organic group having no fluorine atom. The carbon number of the alkyl group is preferably 1 to 10, more preferably 1 to 4. The alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group. Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, more preferably a fluorine atom or CF ₃ , and more preferably both Xf are fluorine atoms.

^R4 and ^R5 independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom. When there are plural ^R4 and ^R5 , ^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 above alkyl group may have a substituent. As _R4 and _R5 , a hydrogen atom is preferred.

L represents a divalent linking group. The definition of L is the same as that of L in formula (AN1).

W represents an organic group containing a cyclic structure. Among them, a cyclic organic group is preferred. As the cyclic organic group, for example, an alicyclic group, an aromatic group, and a heterocyclic group can be cited. The alicyclic group can be monocyclic or polycyclic. As a monocyclic alicyclic group, for example, monocyclic cycloalkyl groups such as cyclopentyl, cyclohexyl, and cyclooctyl can be cited. As a polycyclic alicyclic group, for example, polycyclic cycloalkyl groups such as norbornyl, tricyclodecyl, tetracyclodecyl, tetracyclododecyl, and adamantyl can be cited. Among them, preferred are alicyclic groups with a bulk structure and having more than 7 carbon atoms, such as norbornyl, tricyclodecyl, tetracyclodecyl, tetracyclododecyl, and adamantyl.

The aryl group may be monocyclic or polycyclic. Examples of the aryl group include phenyl, naphthyl, phenanthrenyl, and anthracenyl. The heterocyclic group may be monocyclic or polycyclic. Among them, when the heterocyclic group is polycyclic, the diffusion of the acid can be further suppressed. The heterocyclic group may be aromatic or non-aromatic. Examples of the aromatic heterocyclic group include furan ring, thiophene ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, and pyridine ring. Examples of the non-aromatic heterocyclic group include tetrahydropyran ring, lactone ring, sultone ring, and decahydroisoquinoline ring. As the heterocyclic ring in the heterocyclic group, a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring is preferred.

The cyclic organic group may have a substituent. Examples of the substituent include an alkyl group (may be any of a linear and branched group, preferably having 1 to 12 carbon atoms), a cycloalkyl group (may be any of a monocyclic, polycyclic, and spirocyclic group, preferably having 3 to 20 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), a hydroxyl group, an alkoxy group, an ester group, an amide group, a carbamate group, a urea group, a thioether group, a sulfonamide group, and a sulfonate group. In addition, the carbon (carbon that contributes to the formation of the ring) constituting the cyclic organic group may also be a carbonyl carbon.

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

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

[Chemical formula 49]

In formula (AN3), Ar represents an aromatic group (phenyl group, etc.), and may further have a substituent other than a sulfonic acid anion and a -(D-B) group. Examples of the substituent that may be further possessed include a fluorine atom and a hydroxyl group. n represents an integer greater than 0. As n, 1 to 4 is preferred, 2 to 3 is more preferred, and 3 is further preferred.

D represents a single bond or a divalent linking group. Examples of the divalent linking group include an ether group, a thioether group, a carbonyl group, a sulfide group, a sulfonyl group, a sulfonate group, an ester group, and a group composed of a combination of two or more of these groups.

B represents an alkyl group. As B, an aliphatic alkyl group is preferred, and an isopropyl group, a cyclohexyl group, or an aryl group which may further have a substituent (such as tricyclohexylphenyl) is more preferred.

As the non-nucleophilic anion, a disulfonamide anion is also preferred. For example, the disulfonamide anion is an anion represented by ^N- ( _SO2 - ^Rq ) ₂ . Here, ^Rq represents an alkyl group which may have a substituent, preferably a fluoroalkyl group, and more preferably a perfluoroalkyl group. Two Rq ^groups may bond to each other to form a ring. The group formed by two Rq ^groups bonding to each other is preferably an alkylene group which may have a substituent, preferably a fluoroalkylene group, and more preferably a perfluoroalkylene group. The carbon number of the above alkylene group is preferably 2 to 4.

Examples of non-nucleophilic anions include anions represented by the following formulae (d1-1) to (d1-4).

[Chemical formula 50]

[Chemical formula 51]

In formula (d1-1), R ⁵¹ represents a alkyl group (eg, an aryl group such as a phenyl group) which may have a substituent (eg, a hydroxy group).

In formula (d1-2), Z ^2c represents a alkyl group having 1 to 30 carbon atoms which may have a substituent (wherein the carbon atom adjacent to S is not substituted by a fluorine atom). The alkyl group in Z ^2c may be a straight chain or a branched chain, or may have a cyclic structure. Furthermore, the carbon atom in the alkyl group (preferably a carbon atom as a ring member atom when the alkyl group has a cyclic structure) may be a carbonyl carbon (-CO-). As the alkyl group, for example, a group having a norbornyl group which may have a substituent can be cited. The carbon atom forming the norbornyl group may be a carbonyl carbon. "Z ^2c -SO ₃ ^- " in formula (d1-2) is preferably different from the anion represented by the above formulas (AN1) to (AN3). For example, Z ^2c is preferably other than an aryl group. For example, the atoms at the α-position and β-position relative to -SO ₃ ^- in Z ^2c are preferably atoms other than a carbon atom having a fluorine atom as a substituent. For example, the atom at the α-position and/or the atom at the β-position relative to -SO ₃ ^- in Z ^2c are preferably ring member atoms in a cyclic group.

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

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

The organic anion may be used alone or in combination of two or more. Preferred examples are shown below.

[Chemical formula 52]

From the viewpoint of suppressing development defects, the composition of the present invention preferably contains a salt (C) having a group decomposable by the action of an acid, and more preferably contains a compound represented by the following general formula (c1) as a photoacid generator.

[Chemical formula 53]

In the general formula (c1), L represents a single bond or a divalent linking group. When there are plural Ls, the plural Ls may be the same or different. A represents a group decomposed by the action of an acid. When there are plural A, the plural A may be the same or different. nc represents an integer of 1 to 5. Xc represents an n+1-valent linking group. Mc ⁺ represents a coronium ion or an iodonium ion.

In the general formula (c1), L represents a single bond or a divalent linking group. Examples of the divalent linking group represented by L include -CO-, -O-, -S-, -SO-, -SO ₂ -, alkyl groups (e.g., alkylene groups, cycloalkylene groups, alkenylene groups, and arylene groups), and linking groups formed by a plurality of these groups. Among them, L is preferably an alkylene group, an arylene group, an -arylene-alkylene group having a fluorine atom or an iodine atom, a -COO-Rt- group, or an -O-Rt- group. In the formula, Rt represents an alkylene group or a cycloalkylene group.

The arylene group is preferably a phenylene group. The alkylene group may be linear or branched. The carbon number of the alkylene group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the alkylene group having fluorine atoms or iodine atoms is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and further preferably 3 to 6. Rt is preferably an alkylene group having 1 to 5 carbon atoms, and is more preferably a -CH ₂ - group, a -(CH ₂ ) ₂ - group, or a -(CH ₂ ) ₃ - group.

L is particularly preferably an arylene group, an alkylene group or a single bond, and most preferably a phenylene group or a single bond.

In the general formula (c1), A represents a group that decomposes by the action of an acid. The group that decomposes by the action of an acid preferably has a structure in which a polar group is protected by a group that is decomposed by the action of an acid (degrouping).

As the polar group, there can be cited the polar group recorded in the repeating unit having an acid-decomposable group of the above-mentioned resin (A), among which a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group) or a sulfonic acid group is preferred, and a carboxyl group or a phenolic hydroxyl group is more preferred. As the group that is released by the action of an acid, for example, there can be cited the groups represented by formulas (Y1) to (Y4) recorded in the above-mentioned resin (A).

In the general formula (c1), nc represents an integer of 1 to 5. Preferably, nc is an integer of 1 to 3.

In the general formula (c1), Xc represents an n+1 valent linking group. Xc is preferably an aromatic ring group, more preferably an aromatic ring group having 6 to 20 carbon atoms, and further preferably a benzene ring group.

In the general formula (c1), Mc ⁺ represents a coronium ion or an iodonium ion. Examples of the coronium ion and the iodonium ion include the cation represented by the above formula (ZaI) and the cation represented by the formula (ZaII), and preferably the above cation (ZaI-1), cation (ZaI-2), cation (ZaI-3b), and cation (ZaI-4b).

The compound represented by the above general formula (c1) is more preferably a compound represented by the following general formula (c2).

[Chemical formula 54]

In the general formula (c2), L, A, nc and Mc ⁺ have the same meanings as L, A, nc and Mc ⁺ in the above general formula (c1), and the preferred embodiments are also the same.

Specific examples of the compound represented by the general formula (c1) are shown below, but the present invention is not limited thereto.

[Chemical formula 55]

[Chemical formula 56]

[Chemical formula 57]

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

(Compound (I)) Compound (I) is a compound having one or more of the following structural sites X and one or more of the following structural sites Y, and is a compound that generates an acid containing the following first acid site derived from the following structural site X and the following second acid site derived from the following structural site Y by irradiation with actinic rays or radiation. Structural site X: A structural site composed of anionic site A ₁ ^- and cationic site M ₁ ⁺ , and forming a first acid site represented by HA ₁ by irradiation with actinic rays or radiation. Structural site Y: A structural site composed of anionic site A ₂ ^- and cationic site M ₂ ⁺ , and forming a second acid site represented by HA ₂ by irradiation with actinic rays or radiation. The above compound (I) satisfies the following condition I.

Condition I: In the above compound (I), the compound PI formed by replacing the cationic site _M1 ⁺ in the above structural site X and the cationic site _M2 ⁺ in the above structural site Y with H ⁺ has an acid dissociation constant a1 of the acidic site represented by _HA1 derived from replacing the cationic site _M1 ⁺ in the above structural site X with H ⁺ and an acid dissociation constant a2 of the acidic site represented by _HA2 derived from replacing the cationic site _M2 ⁺ in the above structural site Y with H ⁺ , and the acid dissociation constant a2 is greater than the acid dissociation constant a1.

The condition I will be described in more detail below. When compound (I), for example, is a compound that produces an acid having one of the first acidic sites derived from the structural site X and one of the second acidic sites derived from the structural site Y, compound PI is equivalent to a "compound having HA ₁ and HA ₂ ". The acid dissociation constant a1 and the acid dissociation constant a2 of compound PI are more specifically, when the acid dissociation constant of compound PI is obtained, the pKa of compound PI when it becomes a "compound having A ₁ ^- and HA ₂ " is the acid dissociation constant a1, and the pKa of the "compound having A ₁ ^- and HA ₂ " when it becomes a "compound having A ₁ ^- and A ₂ ^- " is the acid dissociation constant a2.

When compound (I) is, for example, a compound that produces an acid having two first acid sites derived from the structural site X and one second acid site derived from the structural site Y, compound PI is equivalent to "a compound having two HA _1s and one HA ₂ ". When the acid dissociation constant of compound PI is obtained, the acid dissociation constant when compound PI becomes "a compound having one A ₁ ^- , one HA ₁ and one HA ₂ " and the acid dissociation constant when "a compound having one A ₁ ^- , one HA ₁ and one HA ₂ " becomes "a compound having two A ₁ ^-s and one HA ₂ " are equivalent to the above-mentioned acid dissociation constant a1. The acid dissociation constant when "a compound having two A ₁ ^-s and one HA ₂ " becomes "a compound having two A ₁ ^-s and A ₂ ^-s " is equivalent to the acid dissociation constant a2. That is, in the case of compound PI, when there are a plurality of acid dissociation constants of the acid site represented by HA ₁ derived from the substitution of the cationic site M ₁ ⁺ in the structural site X with H ⁺ , the value of the acid dissociation constant a2 is greater than the maximum value of the plurality of acid dissociation constants a1. Furthermore, when the acid dissociation constant when compound PI is "a compound having one A ₁ ^- , one HA ₁ and one HA ₂ " is ab, and the acid dissociation constant when "a compound having one A ₁ ^- , one HA ₁ and one HA ₂ " is "a compound having two A ₁ ^- and one HA ₂ " is ab, the relationship between aa and ab satisfies aa<ab.

The acid dissociation constant a1 and the acid dissociation constant a2 can be determined by the above-mentioned method for determining the acid dissociation constant. The compound PI is equivalent to the acid generated when the compound (I) is irradiated with actinic rays or radiation. When the compound (I) has two or more structural parts X, the structural parts X may be the same or different. Furthermore, the two or more A ₁ ^- and the two or more M ₁ ⁺ may be the same or different. In the compound (I), the A ₁ ^- and the A ₂ ^- , and the M ₁ ⁺ and the M ₂ ⁺ may be the same or different, but the A ₁ ^- and the A ₂ ^- are preferably different.

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

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

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

The anionic site A ₁ ^- and the anionic site A ₂ ^- are structural sites containing negatively charged atoms or atomic groups, and examples thereof include structural sites selected from the group consisting of formulae (AA-1) to (AA-3) and formulae (BB-1) to (BB-6) shown below. The anionic site A ₁ ^- is preferably a site that can form an acidic site with a small acid dissociation constant, more preferably any one of formulae (AA-1) to (AA-3), and even more preferably any one of formulae (AA-1) and (AA-3). As the anionic site _A2- ^, it is preferred that the anionic site can form an acidic site ^having a larger acid dissociation constant than the anionic site _A1- , more preferably any one of formulas (BB-1) to (BB-6), and further preferably any one of formulas (BB-1) and (BB-4). In the following formulas (AA-1) to (AA-3) and (BB-1) to (BB-6), * represents a bonding position. In formula (AA-2), ^RA represents a monovalent organic group. The monovalent organic group represented by ^RA is not particularly limited, and examples thereof include cyano, trifluoromethyl, and methanesulfonyl.

[Chemical formula 58]

[Chemical formula 59]

The cationic site _M1 ⁺ and the cationic site _M2 ⁺ are structural sites containing positively charged atoms or atomic groups, and examples thereof include organic cations having a univalent charge. Examples of organic cations include organic cations represented by the above-mentioned M ⁺ .

(Compound (II)) Compound (II) is a compound having two or more of the above structural sites X and one or more of the following structural sites Z, and is a compound that generates an acid including two or more first acid sites derived from the above structural site X and the above structural site Z by irradiation with actinic rays or radiation. Structural site Z: a non-ionic site capable of neutralizing an acid.

In compound (II), the definitions of the structural part X and the definitions of A ₁ ^- and M ₁ ⁺ are the same as the definitions of the structural part X and the definitions of A ₁ ^- and M ₁ ⁺ in compound (I) above, and the preferred embodiments are also the same.

In the compound (II), in the compound PII obtained by replacing the cationic site _M1 ⁺ in the structural site X with H ⁺ , the preferred range of the acid dissociation constant a1 of the acidic site represented by _HA1 derived from the replacement of the cationic site _M1 ⁺ in the structural site X with H ⁺ is the same as the acid dissociation constant a1 in the compound PI. In addition, for example, when the compound (II) is a compound that generates an acid having two acid sites derived from the first acidic site X and the structural site Z, the compound PII is equivalent to a "compound having two _HA1 ". When the acid dissociation constant of the compound PII is obtained, the acid dissociation constant when the compound PII becomes a "compound having one A ₁ ^- and one HA ₁ " and the acid dissociation constant when the "compound having one A ₁ ^- and one HA ₁ " becomes a "compound having two A ₁ ^- " are equivalent to the acid dissociation constant a1.

The acid dissociation constant a1 can be determined by the above-mentioned method for determining the acid dissociation constant. The compound PII is equivalent to the acid generated when compound (II) is irradiated with actinic rays or radiation. In addition, the two or more structural parts X may be the same or different. The two or more A ₁ ^- and the two or more M ₁ ⁺ may be the same or different.

The non-ionic part capable of neutralizing the acid in the structural part Z is not particularly limited, and for example, it is preferably a part containing a group capable of electrostatically interacting with a proton or a functional group having an electron. As the group capable of electrostatically interacting with a proton or the functional group having an electron, for example, a functional group having a macrocyclic structure such as a cyclic polyether or a functional group having a nitrogen atom containing a non-shared electron pair that does not contribute to π conjugation can be cited. The nitrogen atom having a non-shared electron pair that does not contribute to π conjugation refers to, for example, a nitrogen atom having a partial structure shown in the following formula.

[Chemical formula 60]

Examples of the partial structure of the group capable of electrostatically interacting with protons or the functional group having electrons include crown ether structure, nitrogen-doped crown ether structure, primary to tertiary amine structure, pyridine structure, imidazole structure and pyrazine structure, among which primary to tertiary amine structure is preferred.

Examples of sites other than cations that Compound (I) and Compound (II) may have are shown.

[Chemical formula 61]

[Chemical formula 62]

As the photoacid generator, for example, compounds B-1 to B-3 used in Examples can be used.

The content of the photoacid generator is not particularly limited, but from the viewpoint of making the cross-sectional shape of the formed pattern more rectangular, it is preferably 0.5% by mass or more, and more preferably 1.0% by mass or more, relative to the total solid content of the composition of the present invention. The above content is preferably 50.0% by mass or less, more preferably 30.0% by mass or less, and further preferably 25.0% by mass or less, relative to the total solid content of the composition of the present invention. One type of photoacid generator may be used alone, or two or more types may be used.

[Acid diffusion control agent] The composition of the present invention may further contain an acid diffusion control agent. The acid diffusion control agent functions as a quencher that captures the acid generated from the photoacid generator or the like during exposure and suppresses the reaction of the acid-decomposable resin in the unexposed portion due to the excess generated acid. The type of acid diffusion control agent is not particularly limited, and examples thereof include alkaline compounds (DA), low molecular weight compounds having nitrogen atoms and groups that are released by the action of an acid (DB), and compounds whose acid diffusion control ability is reduced or eliminated by irradiation with actinic rays or radiation (DC). As the compound (DC), there can be cited an onium salt compound (DD) that is a relatively weak acid with respect to an acid generated by a photoacid generator (e.g., salt (C) etc.), and an alkaline compound (DE) whose alkalinity is reduced or disappears by irradiation with actinic rays or radiation. As a specific example of the alkaline compound (DA), for example, those described in paragraphs [0132] to [0136] of International Publication No. 2020/066824 can be cited. As a specific example of the alkaline compound (DE) whose alkalinity is reduced or disappears by irradiation with actinic rays or radiation, there can be cited paragraph [0137] of International Publication No. 2020/066824. ～[0155] and those described in paragraph [0164] of International Publication No. 2020/066824. As specific examples of low molecular weight compounds (DB) having a nitrogen atom and a group that is released by the action of an acid, those described in paragraphs [0156] to [0163] of International Publication No. 2020/066824 can be cited. As specific examples of onium salt compounds (DD) that are relatively weak acids relative to the photoacid generator, for example, those described in paragraphs [0305] to [0314] of International Publication No. 2020/158337 can be cited.

In addition to the above, for example, known compounds disclosed in paragraphs [0627] to [0664] of U.S. Patent Application Publication No. 2016/0070167A1, paragraphs [0095] to [0187] of U.S. Patent Application Publication No. 2015/0004544A1, paragraphs [0403] to [0423] of U.S. Patent Application Publication No. 2016/0237190A1, and paragraphs [0259] to [0328] of U.S. Patent Application Publication No. 2016/0274458A1 can be appropriately used as acid diffusion control agents.

When the composition of the present invention contains an acid diffusion control agent, the content of the acid diffusion control agent is preferably 0.1 to 15.0% by mass, and more preferably 0.5 to 15.0% by mass, relative to the total solid content of the composition of the present invention. One or more acid diffusion control agents may be used. When two or more acid diffusion control agents are used, it is preferred that their total content is within the above-mentioned preferred content range.

[Hydrophobic resin] The composition of the present invention may further contain a hydrophobic resin different from the resin (A). The hydrophobic resin is preferably designed to be preferentially present on the surface of the photoresist film, but unlike the surfactant, it does not necessarily have a hydrophilic group in its molecule and may not contribute to the uniform mixing of polar and non-polar substances. As the effects brought about by the addition of the hydrophobic resin, the static and dynamic contact angles of the photoresist film surface relative to water and the suppression of outgassing can be cited.

From the perspective of partial localization of the membrane surface, the hydrophobic resin preferably has one or more of fluorine atoms, silicon atoms, and CH ₃ partial structures contained in the side chain portion of the resin, and more preferably has two or more. The above-mentioned hydrophobic resin preferably has a alkyl group with a carbon number of 5 or more. These groups can exist in the main chain of the resin and can also be substituted in the side chain. As hydrophobic resins, compounds described in paragraphs [0275] to [0279] of International Publication No. 2020/004306 can be cited.

When the composition of the present invention contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01 to 20.0 mass %, and more preferably 0.1 to 15.0 mass %, relative to the total solid content of the composition of the present invention. One or more hydrophobic resins may be used. When two or more hydrophobic resins are used, it is preferred that the total content is within the above-mentioned preferred content range.

[Surfactant] The composition of the present invention may contain a surfactant. When the 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 the fluorine-based and/or silicon-based surfactant, the surfactant disclosed in paragraphs [0218] and [0219] of International Publication No. 2018/193954 can be cited.

When the composition of the present invention contains a surfactant, the content of the surfactant is preferably 0.0001 to 2.0 mass%, more preferably 0.0005 to 1.0 mass%, and further preferably 0.1 to 1.0 mass%, relative to the total solid content of the composition of the present invention. One surfactant may be used, or two or more surfactants may be used. When two or more surfactants are used, it is preferred that the total content thereof is within the above-mentioned preferred content range.

[Solvent] The composition of the present invention preferably contains a solvent. The solvent preferably includes at least one of (M1) and (M2), wherein (M1) is propylene glycol monoalkyl ether carboxylate, and (M2) is at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate, acetate, alkoxypropionate, chain ketone, cyclic ketone, lactone and alkyl carbonate. In addition, the above-mentioned solvent may further include components other than components (M1) and (M2).

From the perspective of improving the coating properties of the composition of the present invention and reducing the number of development defects of the pattern, it is preferred to combine the above-mentioned solvent with the above-mentioned resin. Since the solubility, boiling point and viscosity of the above-mentioned resin are well balanced, the above-mentioned solvent can suppress the uneven film thickness of the photoresist film and the generation of precipitates during the spin coating process. The details of component (M1) and component (M2) are described in paragraphs [0218] to [0226] of International Publication No. 2020/004306, and these contents are incorporated into this specification.

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

The content of the solvent in the composition of the present invention is preferably set to a solid content concentration of 0.5 to 30% by mass, more preferably 1 to 20% by mass. In this way, the coating properties of the composition of the present invention can be further improved.

[Other additives] The composition of the present invention may further contain a dissolution inhibitor, a dye, a plasticizer, a photosensitizer, a light absorber, and/or a compound that promotes solubility relative to the developer (for example, a phenol compound with a molecular weight of less than 1000, or an alicyclic or aliphatic compound containing a carboxyl group).

The above-mentioned "dissolution inhibiting compound" refers to a compound having a molecular weight of 3,000 or less, which is decomposed by the action of an acid and has a reduced solubility in an organic developer.

The composition of the present invention can be preferably used as a photosensitive composition for EUV exposure. The wavelength of EUV light is 13.5nm, which is shorter than ArF (wavelength 193nm) light, so the number of incident photons is small when exposed at the same sensitivity. Therefore, the influence of "photon shot noise" in which the number of photons is probabilistically biased is greater, resulting in deterioration of line edge roughness (LER) and bridging defects. In order to reduce photon shot noise, there is a method of increasing the exposure amount to increase the number of incident photons, but there is a trade-off relationship with the requirement for high sensitivity.

When the A value obtained by the following formula (1) is high, the absorption efficiency of EUV light and electron beam of the photoresist film formed by the photoresist composition becomes higher, which can effectively reduce the photon shot noise. The A value represents the absorption efficiency of EUV light and electron beam of the mass ratio of the photoresist film. Formula (1): A=([H]×0.04+[C]×1.0+[N]×2.1+[O]×3.6+[F]×5.6+[S]×1.5+[I]×39.5)/([H]×1+[C]×12+[N]×14+[O]×16+[F]×19+[S]×32+[I]×127) The A value is preferably 0.120 or more. There is no particular upper limit, but when the A value is too large, the transmittance of the photoresist film to EUV light and electron beams will decrease, and the optical image profile in the photoresist film will deteriorate, making it difficult to obtain a good pattern shape. Therefore, it is preferably below 0.240, and more preferably below 0.220.

In formula (1), [H] represents the molar ratio of hydrogen atoms derived from the total solid components relative to the total atoms of the total solid components in the actinic radiation or radiation-sensitive resin composition, [C] represents the molar ratio of carbon atoms derived from the total solid components relative to the total atoms of the total solid components in the actinic radiation or radiation-sensitive resin composition, [N] represents the molar ratio of nitrogen atoms derived from the total solid components relative to the total atoms of the total solid components in the actinic radiation or radiation-sensitive resin composition, and [O] represents the molar ratio of oxygen atoms derived from the total solid components relative to the total atoms of the actinic radiation or radiation-sensitive resin composition. [F] represents the molar ratio of all atoms of the total solid components in the photosensitive or radiation-sensitive resin composition, [S] represents the molar ratio of all atoms of the total solid components in the photosensitive or radiation-sensitive resin composition, and [I] represents the molar ratio of all atoms of the total solid components in the photosensitive or radiation-sensitive resin composition. For example, when the photoresist composition contains an acid-decomposable resin, a photoacid generator, an acid diffusion control agent, and a solvent, the acid-decomposable resin, the photoacid generator, and the acid diffusion control agent are equivalent to the solid component. That is, all the atoms of the total solid component are equivalent to the sum of all the atoms derived from the resin, all the atoms derived from the photoacid generator, and all the atoms derived from the acid diffusion controller. For example, [H] represents the molar ratio of hydrogen atoms derived from the total solid component to all the atoms of the total solid component. If the above example is used for explanation, [H] represents the molar ratio of the sum of hydrogen atoms derived from the acid-decomposable resin, hydrogen atoms derived from the photoacid generator, and hydrogen atoms derived from the acid diffusion controller to the sum of all the atoms derived from the acid-decomposable resin, all the atoms derived from the photoacid generator, and all the atoms derived from the acid diffusion controller.

The A value can be calculated by calculating the atomic ratio of the total solid components in the photoresist composition when the structure and content of the components are known. Even if the components are unknown, the atomic ratio of the components can be calculated by elemental analysis or other analytical methods for the photoresist film obtained by evaporating the solvent components of the photoresist composition.

<Photosensitive or radiation-sensitive film, pattern forming method> The present invention also relates to a photosensitive or radiation-sensitive film formed by the composition of the present invention. The photosensitive or radiation-sensitive film of the present invention is preferably a photoresist film. The steps of the pattern forming method using the composition of the present invention are not particularly limited, and preferably include the following processes. Process 1: Process of forming a photosensitive or radiation-sensitive film on a substrate using the composition of the present invention Process 2: Process of exposing the photosensitive or radiation-sensitive film Process 3: Process of developing the exposed photosensitive or radiation-sensitive film using a developer The steps of each of the above processes will be described in detail below.

(Process 1: Photosensitive or radiation-sensitive film formation process) Process 1 is a process for forming a photosensitive or radiation-sensitive film on a substrate using the composition of the present invention.

As a method of forming a photosensitive or radiation-sensitive film on a substrate from the composition of the present invention, for example, a method of coating the composition of the present invention on a substrate can be cited. In addition, it is preferred to filter the composition of the present invention with a filter 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 further preferably 0.03 μm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

The composition of the present invention can be applied to a substrate (e.g., silicon, silicon dioxide coating) such as that used to manufacture integrated circuit components by an appropriate coating method such as a rotator or a coater. The coating method is preferably rotary coating using a rotator. The rotation speed when using a rotator for rotary coating is preferably 1000 to 3000 rpm (rotations per minute). After applying the composition of the present invention, the substrate can be dried and a photosensitive or radiation-sensitive film can be formed. In addition, various base films (inorganic films, organic films, anti-reflective films) can be formed under the photosensitive or radiation-sensitive film as needed.

As a drying method, for example, a method of drying by heating can be cited. Heating can be implemented by a device equipped in a common exposure machine and/or developer, or can be implemented using a hot plate or the like. The heating temperature is preferably 80 to 150° C., more preferably 80 to 140° C., and further preferably 80 to 130° C. The heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, and further preferably 60 to 600 seconds.

The film thickness of the photosensitive or radiation-sensitive film is not particularly limited, but is preferably 10 to 120 nm from the viewpoint of forming a fine pattern with higher precision. In the case of EUV exposure, the film thickness of the photosensitive or radiation-sensitive film is more preferably 10 to 65 nm, and more preferably 15 to 50 nm. In the case of ArF immersion exposure, the film thickness of the photosensitive or radiation-sensitive film is more preferably 10 to 120 nm, and more preferably 15 to 90 nm.

In addition, a top coating composition can be used to form a top coating on the upper layer of the photosensitive radiation or radiation-sensitive film. The top coating composition is preferably not mixed with the photosensitive radiation or radiation-sensitive film, and can be uniformly coated on the upper layer of the photoresist film. The top coating is not particularly limited, and a previously known top coating can be formed by a previously known method. For example, the top coating can be formed according to the description in paragraphs [0072] to [0082] of Japanese Patent Publication No. 2014-059543. For example, it is preferred to form a top coating containing an alkaline compound as described in Japanese Patent Publication No. 2013-61648 on a photosensitive or radiation-sensitive film. Specific examples of alkaline compounds that may be contained in the top coating include alkaline compounds that may be contained in the composition of the present invention. The top coating is also preferably a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond.

(Process 2: Exposure process) Process 2 is a process for exposing the photosensitive or radiation-sensitive film. As a method of exposure, a method of irradiating the formed photosensitive or radiation-sensitive film with actinic rays or radiation through a prescribed mask can be cited. As actinic rays or radiation, infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams can be cited. Far ultraviolet light with a wavelength of 1 to 200 nm and less is preferably less than 250 nm, more preferably less than 220 nm, and more preferably less than 220 nm. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), _F2 excimer laser (157 nm), EUV (13.5 nm), X-rays, and electron beams are particularly preferred.

It is preferred to bake (heat) after exposure and before development. Baking can promote the reaction of the exposed part, thereby making the sensitivity and pattern shape better. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and more preferably 80 to 130°C. The heating time is preferably 10 to 1000 seconds, more preferably 10 to 180 seconds, and more preferably 30 to 120 seconds. Heating can be implemented by a device equipped in a conventional exposure machine and/or developer, or by using a hot plate, etc. This process is also called post-exposure baking.

(Process 3: Development process) Process 3 is a process of developing the exposed photosensitive or radiation-sensitive film using a developer to form a pattern. The developer can be an alkaline developer or a developer containing an organic solvent (hereinafter also referred to as an organic developer).

As developing methods, for example, there are a method of immersing a substrate in a tank filled with developer for a certain period of time (immersion method), a method of depositing developer on the substrate surface by surface tension and allowing the developer to stand for a certain period of time to perform development (puddle method), a method of spraying developer onto the substrate surface (spraying method), and a method of continuously spraying developer while scanning a developer nozzle at a certain speed on a substrate rotating at a certain speed (dynamic dispensing method). In addition, after the development process is performed, a process of stopping the development while replacing the solvent with another solvent can also be implemented. The developing time is not particularly limited as long as it is a time for the resin in the unexposed part to fully dissolve, and is preferably 10 to 300 seconds, more preferably 20 to 120 seconds. The temperature of the developer is preferably 0 to 50°C, more preferably 15 to 35°C.

The alkaline developer is preferably an alkaline aqueous solution containing an alkali. The type of the alkaline aqueous solution is not particularly limited. For example, there can be cited alkaline aqueous solutions containing quaternary ammonium salts represented by tetramethylammonium hydroxide, inorganic bases, primary amines, secondary amines, tertiary amines, alcohol amines, or cyclic amines. Among them, the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt represented by tetramethylammonium hydroxide (TMAH). Appropriate amounts of alcohols, surfactants, etc. can be added to the alkaline developer. The alkaline concentration of the alkaline developer is generally preferably 0.1 to 20% by mass. The pH of the alkaline developer is generally preferably 10.0 to 15.0.

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.

The above solvents may be mixed in multiple forms, or may be mixed with solvents other than the above or water. The water content of the developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, further preferably less than 10% by mass, and particularly preferably substantially free of water. The content of the organic solvent relative to the organic developer, relative to the total amount of the 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, further preferably 90% by mass or more and 100% by mass or less, and particularly preferably 95% by mass or more and 100% by mass or less.

(Other processes) The above pattern forming method is preferably a process including cleaning with a rinse solution after process 3.

As a rinse liquid used in a rinse process after a process of developing with an alkaline developer, for example, pure water can be cited. In addition, an appropriate amount of a surfactant can be added to pure water. An appropriate amount of a surfactant can also be added to the rinse liquid.

The rinse solution used in the rinse process after the development process using an organic developer is not particularly limited as long as it does not dissolve the pattern, and a solution containing a general organic solvent can be used. The rinse solution is preferably a rinse solution 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.

The method of the rinsing process is not particularly limited. For example, there can be cited a method of continuously spraying a rinsing liquid onto a substrate rotating at a certain speed (spin coating method), a method of immersing the substrate in a tank filled with a rinsing liquid for a certain period of time (immersion method), and a method of spraying the rinsing liquid onto the surface of the substrate (spray coating method). In addition, the pattern forming method can include a heating process (Post Bake) after the rinsing process. Through this process, the developer and rinsing liquid remaining between and inside the patterns are removed by baking. In addition, through this process, it also has the effect of annealing the photoresist pattern and improving the surface roughness of the pattern. The heating process after the rinsing process is usually carried out at 40 to 250°C (preferably 90 to 200°C) for 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

Furthermore, the formed pattern can be used as a mask to perform etching processing on the substrate. That is, the pattern formed in process 3 can be used as a mask to process the substrate (or the lower film and the substrate) and form a pattern on the substrate. The processing method of the substrate (or the lower film and the substrate) is not particularly limited, but it is preferably a method of using the pattern formed in process 3 as a mask to form a pattern on the substrate by dry etching the substrate (or the lower film and the substrate). Dry etching is preferably oxygen plasma etching.

The various materials used in the composition and pattern forming method of the present invention (e.g., solvent, developer, rinse solution, anti-reflection film forming composition, top coating forming composition, etc.) preferably do not contain impurities such as metals. The impurity content contained in these materials is preferably 1 mass ppm (parts per million) or less, more preferably 10 mass ppb (parts per billion) or less, further preferably 100 mass ppt (parts per trillion) or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. The lower limit is not particularly limited, and is preferably 0 mass ppt or more. Here, as metal impurities, 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 can be cited.

As a method for removing impurities such as metal from various materials, for example, a method of filtering using a filter can be cited. Details of filtering using a filter are described in paragraph [0321] of International Publication No. 2020/004306.

As methods for reducing impurities such as metals contained in various materials, for example, there are methods of selecting raw materials with a low metal content as raw materials constituting various materials, methods of filtering the raw materials constituting various materials through a filter, and methods of performing distillation under conditions that suppress contamination as much as possible, such as forming an inner lining in an apparatus using TEFLON (registered trademark).

In addition to filtering with a filter, impurities can also be removed by using an adsorbent material, or a combination of filtering with a filter and an adsorbent material can be used. As the adsorbent material, a known adsorbent material can be used, for example, inorganic adsorbent materials such as silica gel and zeolite, and organic adsorbent materials such as activated carbon can be used. In order to reduce impurities such as metals contained in the above-mentioned materials, it is necessary to prevent the mixing of metal impurities in the manufacturing process. Whether the metal impurities have been fully removed from the manufacturing device can be confirmed by measuring the content of metal components contained in the cleaning solution used to clean the manufacturing device. The content of metal components contained in the cleaning solution after use is preferably less than 100 mass ppt, more preferably less than 10 mass ppt, and further preferably less than 1 mass ppt. There is no special restriction on the lower limit, and it is preferably greater than 0 mass ppt.

Conductive compounds can be added to organic treatment liquids such as rinse liquids to prevent malfunctions of liquid piping and various components (filters, O-rings, and tubes, etc.) due to electrostatic charging and subsequent electrostatic discharge. There is no particular restriction on the conductive compound, and methanol can be cited as an example. There is no particular restriction on the amount of addition, but from the perspective of maintaining better developing characteristics or rinse characteristics, it is preferably 10% by mass or less, and more preferably 5% by mass or less. There is no particular restriction on the lower limit, and it is preferably 0.01% by mass or more. As liquid piping, for example, SUS (stainless steel) or various piping coated with polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene or perfluoroalkoxy resin, etc.) that has been treated with anti-static treatment can be used. Similarly, for filters and O-rings, polyethylene, polypropylene or fluororesins (polytetrafluoroethylene or perfluoroalkoxy resins, etc.) that have been treated with antistatic agents can also be used.

<Method for manufacturing electronic device> This specification also relates to a method for manufacturing an electronic device including the above-mentioned pattern forming method, and an electronic device manufactured by the manufacturing method. As a preferred embodiment of the electronic device of this specification, an embodiment mounted on an electrical or electronic device (home appliances, OA (Office Automation), media-related equipment, optical equipment, and communication equipment, etc.) can be cited. [Example]

The present invention is described in more detail below based on the embodiments. The materials, usage amounts, ratios, processing contents and processing steps shown in the following embodiments can be appropriately changed as long as they do not deviate from the main purpose of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the embodiments shown below.

Various components used in the photoresist compositions of the embodiments and comparative examples are shown below.

<Resin (A)> P-1 to P-10 were used as resin (A). RP-1 to RP-4 were used as resins other than resin (A). For convenience, RP-1 to RP-4 are also shown in the column of resin (A) in Table 1 below. Resin (A) used was a resin synthesized by the synthesis method of resin P-3 described later (Synthesis Example 1).

Table 1 shows the composition ratio (molar % ratio; corresponding from left to right) of each repeating unit disclosed later, the weight average molecular weight (Mw) and the dispersion (Mw/Mn). In addition, the weight average molecular weight (Mw) and dispersion (Pd = Mw/Mn) of the resin were measured by GPC (carrier: tetrahydrofuran (THF)) (polystyrene conversion amount). In addition, the content of the repeating unit was measured by ¹³ C-NMR (nuclear magnetic resonance).

[Table 1]

The structures of the repeating units a-1 to a-6, b-1 to b-4, c-1 to c-7, and d-1 shown in Table 1 are shown below. In addition, when the repeating unit below is a repeating unit having a phenolic hydroxyl group, the ClogP value of the anion state after the hydrogen atom of the phenolic hydroxyl group is dissociated in the monomer corresponding to the repeating unit is also shown. The measurement method is as described above.

[Chemical formula 63]

[Chemical formula 64]

[Chemical formula 65]

[Chemical formula 66]

The synthesis example of P-3 is shown below. Other resins (A) were synthesized in the same manner.

(Synthesis of P-3)

[Chemical formula 67]

First, 15.42 g of compound (a-1m-Ac), 11.92 g of compound (b-1m), 17.91 g of compound (c-1m), and 4.61 g of polymerization initiator V-601 (Wako Junyaku Industries, Ltd.) were dissolved in 81.42 g of cyclohexanone. 54.28 g of cyclohexanone was placed in a reaction vessel and added dropwise to the system at 85°C for 4 hours under a nitrogen atmosphere. The reaction solution was heated and stirred for 2 hours, and then cooled to room temperature. 111.33 g of methanol and 27.83 g of triethylamine were added to the above reaction solution, and after heating and stirring at 70°C for 6 hours, it was cooled to room temperature. The above reaction solution was diluted by adding 90.47 g of ethyl acetate. The diluted solution was added dropwise to 2714 g of hexane/ethyl acetate = 9/1 (mass ratio) to precipitate the polymer and filter it. The filtered solid was rinsed with 300 g of hexane/ethyl acetate = 9/1 (mass ratio). Then, the washed solid was dried under reduced pressure to obtain 27.5 g of resin (P-3).

The composition ratio of each repeating unit in the resin (P-3) (molar % ratio; corresponding from the left) is 40/25/35. As mentioned above, the composition ratio was measured by ¹³ C-NMR. The weight average molecular weight (Mw) of the resin (P-3) is 6000, and the dispersion (Mw/Mn) is 1.60. In addition, as mentioned above, the weight average molecular weight and dispersion of the resin are measured by GPC (carrier: THF).

<Photoacid generator (B)> The structure of the photoacid generator (B) used is shown below.

[Chemical formula 68]

<Acid diffusion control agent> The structure of the acid diffusion control agent used is shown below.

[Chemical formula 69]

<Hydrophobic resin> The structure of the hydrophobic resin used is shown below.

[Chemical formula 70]

<Surfactant> The surfactant used is shown below. W-1: MEGAFAC R08 (manufactured by Dainippon Ink & Chemicals Co., Ltd.)

<Solvent> The solvents used are shown below. S-1: Propylene glycol monomethyl ether acetate (PGMEA: 1-methoxy-2-acetoxypropane) S-2: Propylene glycol monomethyl ether (PGME: 1-methoxy-2-propanol) S-3: Ethyl lactate S-4: γ-butyrolactone

<Preparation of photoresist composition> The components shown in Table 2 were dissolved in the solvent shown in Table 2, a solution was prepared with the solid component concentration shown in Table 2, and the solution was filtered with a polyethylene filter with a pore size of 0.02μm, thereby preparing a photoresist composition. In addition, the so-called solid component means all components except the solvent. The obtained photoresist composition was used in the embodiments and comparative examples. In the table, the "mass %" column shows the content (mass %) of each component relative to the total solid component in the photoresist composition. In addition, Table 3 records the types of solvents used and their mass ratios.

[Table 2]

<Pattern formation method (1): EB exposure, alkaline development (positive type)> The above-mentioned photoresist composition was coated on a 6-inch Si wafer that had been treated with hexamethyldisilazane (HMDS) in advance using a Tokyo Electron spin coater Mark8, and dried on a hot plate at 100°C for 60 seconds to obtain a photoresist film with a film thickness of 100nm. Here, 1 inch is 0.0254m. In addition, the same result can be obtained by replacing the above-mentioned Si wafer with a chromium substrate. The above-mentioned wafer coated with the photoresist film was patterned using an electron beam drawing device (HL750 manufactured by Hitachi, Ltd., accelerating voltage 50KeV). At this time, the drawing was performed in a manner to form a 1:1 line and space. After electron beam drawing, the wafer was heated at 100°C for 60 seconds on a hot plate, developed with a 2.38% by mass tetramethylammonium hydroxide aqueous solution for 30 seconds, rinsed with pure water, and then rotated at 4000 rpm for 30 seconds, and then heated at 95°C for 60 seconds, thus obtaining a photoresist pattern with a line width of 50nm and a 1:1 line and space pattern.

<Performance evaluation> [LWR performance] The line and space pattern with a line width of 50nm (line/space = 1/1) analyzed by the above method was observed from above the pattern using a length-measuring scanning electron microscope (SEM (S-9380II manufactured by Hitachi Ltd.)). The line width of the pattern was observed at any point (160 points), and its standard deviation (σ) was calculated. The measured deviation of the line width was evaluated with 3σ, and the value of 3σ (nm) was set as LWR (nm). The smaller the LWR value, the better the LWR performance.

[Pattern formation] The line and space pattern (line/space = 1/1) with a line width of 50 nm analyzed by the above method was observed from the pattern cross section using a scanning electron microscope (SEM (S-9380II manufactured by Hitachi Ltd.)). Patterns with a vertical pattern cross section were evaluated as rectangular, patterns with a pattern bottom thinner than the pattern top were evaluated as T-shaped tops, and patterns with a pattern top thinner than the pattern bottom were evaluated as domes. In practical terms, a rectangular shape is preferred.

[Time-dependent stability] The exposure amount when forming the 50nm line and space pattern (line/space = 1/1) obtained by the above method was measured, and it was defined as the "exposure amount before time". In addition, the above photoresist composition was stored at 40°C for 3 months, and a 50nm line and space pattern (line/space = 1/1) was formed using the same pattern forming method as the above method. The exposure amount when forming the pattern was measured, and it was defined as the "exposure amount after time". The sensitivity change rate was calculated according to the following formula and evaluated. In addition, B or above is preferred for practical use, and A is more preferred. Sensitivity change rate (%) = exposure after time / exposure before time × 100 A: Sensitivity change rate is less than 1% B: Sensitivity change rate is more than 1% and less than 2% C: Sensitivity change rate is more than 2% and less than 5% D: Sensitivity change rate is more than 5%

Table 3 below shows the photoresist compositions used in each of the examples and comparative examples and the results of each of the examples and comparative examples.

[table 3]

(EUV exposure) (Examples 2-1 to 2-20, Comparative Examples 2-1 to 2-4) <Pattern formation method (3): EUV exposure, alkaline development (positive type)> The lower film forming composition AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a base film with a thickness of 20 nm. The photoresist composition shown in Table 2 was applied to the base film and baked at 100°C for 60 seconds to form a photoresist film with a thickness of 50 nm. The obtained silicon wafer with a photoresist film was patterned using an EUV exposure device (made by Exitech, Micro Exposure Tool, NA0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36). In addition, as a reticle, a mask with a line size of 50nm and a line: space ratio of 1:1 was used. After the exposed photoresist film was baked at 100°C for 60 seconds, it was developed with an aqueous solution of tetramethylammonium hydroxide (2.38 mass%) for 30 seconds and then rinsed with pure water for 30 seconds. Then, it was spin-dried and a positive pattern was obtained.

<Performance evaluation> The obtained photoresists were evaluated using the same method as the previous method. The evaluation results are shown in Table 4.

[Table 4]

From the results in Tables 3 and 4, it can be seen that the photoresist composition used in the embodiment can take into account the LWR performance, pattern shape, and time stability at a high level in the formation of extremely fine patterns. The photoresist composition used in Comparative Examples 1-4 contains a resin having repeating units (i), repeating units (ii), and repeating units (iii), but because the repeating unit (ii) (specifically, repeating unit b-3) is equivalent to (equivalent to) the repeating unit (i) (specifically, repeating unit a-1) after decomposition by the action of an acid, the effect of the present invention cannot be obtained. [Industrial Applicability]

According to the present invention, a photosensitive or radiation-sensitive resin composition can be provided, which can take into account LWR performance, pattern shape, and stability over time at a high level in the formation of extremely fine patterns (for example, line width or space width is 50nm or less). In addition, according to the present invention, a photosensitive or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device using the above-mentioned photosensitive or radiation-sensitive resin composition can be provided.

Although the present invention has been described in detail and with reference to specific embodiments, it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Japanese Patent Application No. 2022-138717) filed on August 31, 2022, the contents of which are incorporated into this specification as a reference.

without

without

Claims (11)

A resin composition having photosensitive or radiation-sensitive properties, comprising a resin having the following repeating unit (i), the following repeating unit (ii) and the following repeating unit (iii), wherein when the repeating unit (ii) has a group decomposed by the action of an acid, the repeating unit after the decomposition of the repeating unit (ii) by the action of an acid is not equivalent to the repeating unit (i), (i) is a repeating unit having a phenolic hydroxyl group, and in the monomer equivalent to the repeating unit, the ClogP value of the anion state after the hydrogen atom of the phenolic hydroxyl group is dissociated is greater than -7.50 and less than -1.20, (ii) a repeating unit having a phenolic hydroxyl group, and in a monomer corresponding to the repeating unit, the ClogP value of the anionic state of the hydrogen atom of the phenolic hydroxyl group after dissociation is greater than -0.70 and less than 5.00, (iii) a repeating unit having no phenolic hydroxyl group but having a group whose polarity increases by decomposition by the action of an acid. The resin composition as described in claim 1, wherein the repeating unit (i) is a repeating unit having two or more phenolic hydroxyl groups. The resin composition as claimed in claim 1, wherein the repeating unit (i) is a repeating unit represented by the following general formula (a-1): [Chemical Formula 1] In the general formula (a-1), ^Ra1 represents a hydrogen atom or an alkyl group, ^L1 represents a single bond or -C(=O)O-, m represents an integer of 0 to 2, n represents an integer of 2 to 3, ^Ra2 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group or a group composed of two or more of these groups, and l represents an integer of 0 to 4. When l is 2 or more, a plurality of ^Ra2 groups are the same or different and are bonded to each other to form a ring. The resin composition according to any one of claims 1 to 3, wherein the repeating unit (ii) is a repeating unit represented by the following general formula (a-2): [Chemical Formula 2] In the general formula (a-2), ^Ra3 represents a hydrogen atom or an alkyl group, ^L2 represents a single bond or -C(=O)O-, o represents an integer of 0 to 2, p represents an integer of 1 to 2, ^Ra4 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group or a group composed of two or more of these groups, and q represents an integer of 0 to 4. When q is 2 or more, a plurality of ^Ra4 groups are the same or different and are bonded to each other to form a ring. The resin composition according to any one of claims 1 to 3, wherein the repeating unit (iii) is at least one repeating unit selected from the group consisting of a repeating unit represented by the following general formula (a-3) and a repeating unit represented by the following general formula (a-4), [Chemical Formula 3] In the general formula (a-3), ^Ra5 and ^Ra15 each independently represent a hydrogen atom or an alkyl group, ^L3 represents a single bond or -C(=O)O-, r represents an integer from 0 to 2, s represents an integer from 0 to 4, ^Rp1 represents a group that is dissociated by the action of an acid, t represents an integer from 0 to 4, ^Rp2 represents a group that is dissociated by the action of an acid, at least one of s and t is an integer greater than or equal to 1, u represents an integer from 0 to (5+r×4-st), ^Ra6 represents a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an aryl group, a heteroaryl group, an ester group, a carboxyl group, or a group composed of two or more of these groups, and when u is 2 or more, a plurality of ^Ra6 groups are the same or different and are bonded to each other to form a ring, and ^Ra6 and ^Rp1 , ^Ra6 and R R ^p2 , R ^p1 and R ^p2 are bonded to each other to form a ring, and the aromatic rings bonded to R ^a15 and L ³ are bonded to each other to form a ring, [Chemical Formula 4] In the general formula (a-4), R ^a7 represents a hydrogen atom or an alkyl group, and R ^p3 represents a group that is dissociated by the action of an acid. The resin composition according to any one of claims 1 to 3, wherein the repeating unit (iii) is a repeating unit represented by the general formula (a-3). The resin composition as described in any one of claims 1 to 3, wherein the repeating unit (i) and the repeating unit (ii) are repeating units that do not have a group that is decomposed by the action of an acid. The resin composition as described in any one of claims 1 to 3, further comprising a compound that generates an acid upon irradiation with actinic rays or radiation. A film having actinic radiation sensitivity or radiation sensitivity, which is formed from the resin composition described in any one of claims 1 to 3. A method for forming a pattern, comprising: a process of forming a film having photosensitive or radiation-sensitive properties on a substrate from a composition described in any one of claims 1 to 3; a process of exposing the film; and a process of developing the exposed film using a developer. A method for manufacturing an electronic device, comprising the pattern forming method described in claim 10.