Polymer, resist composition containing said polymer, method for manufacturing member using same, and pattern formation method

Abstract

Provided are: a polymer which mitigates sensitivity decrease caused by a decrease in energy application density in patterning performed by irradiation with strong particle beams or electromagnetic waves of particles and photon energy and which is used in a resist composition having excellent development contrast characteristics and etching resistance; a resist composition containing said polymer; a method for manufacturing a member using said resist composition; and a pattern formation method.　The polymer includes: a unit A which has an onium salt structure and generates acid by irradiation with particle beams or electromagnetic waves; and an organometallic compound-containing unit B having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi, and Te, wherein the unit A is a polymer represented by formula (1). (In general formula (1), R1 is one selected from the group consisting of a hydrogen atom, a linear, branched, or cyclic C1–C6 alkyl group, and a linear, branched, or cyclic C2–C6 alkenyl group, and at least one hydrogen atom in the alkyl group and alkenyl group in R1 may be substituted with a substituent; L is one selected from the group consisting of a direct bond, a carbonyl oxy group, a carbonyl amino group, a phenylene diyl group, a naphthalene diyl group, a phenylene diyl oxy group, a naphthalene diyl oxy group, a phenylene diyl carbonyl oxy group, a naphthalene diyl carbonyl oxy group, a phenylene diyl oxy carbonyl group, and a naphthalene diyl oxy carbonyl group; Sp is one among a direct bond, a linear, branched, or cyclic C1–C6 alkylene group which may have a substituent, and a linear, branched, or cyclic C2–C6 alkenylene group which may have a substituent, and at least one methylene group in Sp may be substituted with a divalent heteroatom-containing group; M+ is a sulfonium cation group or an iodonium cation group; X- is a monovalent anion group; f is an integer of 2-4, and f X- bonded to R, f M+ corresponding to X-, f R1, f L, and f Sp may be respectively the same as or different from each other; and R is a C1-C6 f-valent hydrocarbon group which may have a substituent, at least one hydrogen atom in R may be substituted with a substituent, and at least one methylene group in R may be substituted with a divalent heteroatom-containing group.)

Description

Polymer, resist composition containing the polymer, and method for manufacturing a member and method for forming a pattern using the same

[0001] One aspect of the present invention relates to a polymer used in a resist composition. Further, some aspects of the present invention relate to a resist composition containing the polymer, a method for manufacturing a member, and a method for forming a pattern using the resist composition.

[0002] In recent years, photolithography techniques using photoresists have been actively used to manufacture display devices such as liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays, as well as to form semiconductor devices. For the packaging of the above-mentioned electronic components and products, active energy rays such as i-rays with a wavelength of 365 nm, and longer wavelengths such as h-rays (405 nm) and g-rays (436 nm) are widely used.

[0003] As device integration becomes increasingly high, there is an increasing demand for finer lithography techniques, and there is a trend toward using light with very short wavelengths for exposure, such as KrF excimer lasers (wavelength 248 nm), ArF excimer lasers (wavelength 193 nm), extreme ultraviolet rays (EUV, wavelength 13.5 nm), and electron beams (EB). Lithography techniques using these short wavelength lights, particularly EUV or electron beams, enable production with a single patterning, and therefore it is believed that the need for resist compositions that exhibit high sensitivity to EUV, electron beams, etc. will further increase in the future.

[0004] As exposure light sources become shorter in wavelength, resist compositions are required to have improved lithography properties, such as sensitivity to the exposure light source and resolution capable of reproducing patterns with finer dimensions. Chemically amplified resists are known as resist compositions that satisfy these requirements (see Patent Document 1). However, with conventional chemically amplified resists, as the resolution linewidth of the resist becomes finer, it becomes difficult to sufficiently suppress resist pattern collapse and reduce line edge roughness (LWR) of the line pattern.

[0005] In order to suppress resist pattern collapse, it has been proposed to increase the crosslink density in negative chemically amplified resists. However, this can cause defects such as bridging due to swelling during development, making it difficult to increase the crosslink density while maintaining high sensitivity and maintaining pattern performance.

[0006] In order to suppress the resist pattern collapse of a chemically amplified resist, it has been proposed to reduce the resist film thickness (Non-Patent Document 1).Non-Patent Document 1 proposes a resist containing a metal such as tin as a method for reducing the resist film thickness and improving pattern characteristics.

[0007] JP-A-9-90637 JP-A-2011-53622 JP-A-2010-276910 Proc. of SPIE Vol. 11854 118540A-4 (2021)

[0008] The method of Non-Patent Document 1 allows for pattern transfer in an etching step by utilizing the high etching resistance of the metal in the resist, but has issues with sufficient etching resistance. Furthermore, Non-Patent Document 1 uses a negative resist, making it difficult to utilize for positive resist patterns. One aspect of the present invention aims to provide a polymer for use in a resist composition that has high sensitivity, excellent development contrast characteristics, and high etching resistance. Some aspects of the present invention aim to provide a resist composition containing the polymer, a method for manufacturing a member using the resist composition, and a pattern formation method.

[0009] As a result of extensive research aimed at solving the above-mentioned problems, the present inventors have discovered the following (a) to (d) by using a polymer containing a unit A having a specific onium salt structure and generating an acid upon irradiation with a particle beam or electromagnetic wave, and an organometallic compound-containing unit B having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi, and Te as the polymer in a resist composition, and have completed several aspects of the present invention. (a) By including the unit A in the polymer, not only is it possible to utilize the acid generated from the onium salt of unit A upon irradiation with a particle beam or electromagnetic wave, particularly electron beam or EUV, in a reaction, but the generated acid also decomposes the polymer, reducing the molecular weight of the polymer and making it more soluble in a developer. (b) By including the unit B in the polymer, etching resistance is achieved. (c) The Lewis acidity of the metal used in unit B reacts with the acid generated from unit A, suppressing an acid-catalyzed reaction, thereby controlling acid diffusion. (d) When a polymer containing the unit A and the unit B is used in a positive resist composition that uses an organic solvent as a developer, the exposed areas can be dissolved while maintaining a high development contrast.

[0010] The unit A is characterized by having an f-valent anion and f units having a cationic group corresponding to the f-valent anion, and the f units A are a unit group formed by bonding with the f-valent anion. By forming a polymer having the unit A and the unit B, a resist composition containing the polymer undergoes the following process when irradiated with particle beams, electromagnetic waves, or the like: First, the unit A decomposes, causing a significant polarity change from ionic to nonionic. At the same time, the decomposition of the unit A protonates the f-valent anion, generating an acid. This causes the polymer formed via the f-valent anion to decompose, eliminating the crosslinked structure between the polymer molecules, thereby reducing the polymer molecular weight and changing the polymer's solubility. Because the resist composition containing the polymer can significantly change its solubility through the polarity change caused by the decomposition of the unit A as well as the decomposition of the polymer, it is possible to obtain patterning with high sensitivity and high development contrast without utilizing acid diffusion. When the polymer is used in a positive resist composition using an organic solvent as a developer, it can dissolve exposed areas while maintaining high development contrast.

[0011] One embodiment of the present invention that solves the above-mentioned problems comprises a polymer comprising: a unit A having an onium salt structure and generating an acid upon irradiation with a particle beam or electromagnetic wave; and an organometallic compound-containing unit B having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi, and Te, wherein the unit A is represented by the following formula (1):

[0012]

[0013] In the above general formula (1), R １ is any one selected from the group consisting of a hydrogen atom; a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched, or cyclic alkenyl group having 2 to 6 carbon atoms; １ At least one hydrogen atom in the alkyl group and alkenyl group may be substituted with a substituent.

[0014] L is any one selected from the group consisting of a direct bond, a carbonyloxy group, a carbonylamino group, a phenylenediyl group, a naphthalenediyl group, a phenylenediyloxy group, a naphthalenediyloxy group, a phenylenediylcarbonyloxy group, a naphthalenediylcarbonyloxy group, a phenylenediyloxycarbonyl group, and a naphthalenediyloxycarbonyl group.

[0015] Sp is any one of a direct bond; an optionally substituted linear, branched, or cyclic alkylene group having 1 to 6 carbon atoms; and an optionally substituted linear, branched, or cyclic alkenylene group having 2 to 6 carbon atoms, and at least one methylene group in Sp may be substituted with a divalent heteroatom-containing group.

[0016] M ＋ is a sulfonium cation group or an iodonium cation group. R is an f-valent hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and at least one hydrogen atom in R may be substituted with a substituent, and at least one methylene group in R may be substituted with a divalent heteroatom-containing group. X － is a monovalent anionic group. f is an integer of 2 to 4, and f X's bonded to R － , the X － f M + , f R １ , f L's and f Sp's may be the same or different from each other.

[0017] One embodiment of the present invention is a resist composition containing the above-mentioned polymer. Another embodiment of the present invention is a method for producing a member, including: a resist film formation step of forming a resist film on a substrate using the above-mentioned resist composition; a photolithography step of exposing the resist film using particle beams or electromagnetic waves; and a pattern formation step of developing the exposed resist film using a developer to dissolve the exposed areas, thereby obtaining a photoresist pattern.

[0018] One aspect of the present invention is a pattern formation method including: a resist film formation step of forming a resist film on a substrate using the resist composition; a photolithography step of exposing the resist film using particle beams or electromagnetic waves; and a pattern formation step of developing the exposed resist film using a developer to dissolve the exposed portions, thereby obtaining a photoresist pattern.

[0019] Various embodiments of the present invention are exemplified below. The embodiments shown below can be combined with each other. [1] A polymer comprising: a unit A having an onium salt structure and generating an acid upon irradiation with particle beams or electromagnetic waves; and an organometallic compound-containing unit B having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi, and Te, wherein the unit A is represented by the above formula (1). [2] X － is any one selected from the group consisting of alkyl sulfate anion; aryl sulfate anion; alkyl sulfonate anion; aryl sulfonate anion; alkyl carboxylate anion; aryl carboxylate anion; dialkylsulfonylimide anion; trialkylsulfonate methide anion; tetrakisphenylborate anion; － At least one hydrogen atom of the alkyl group and the aryl group in X may be substituted with a substituent; － [3] The polymer according to [1] or [2], wherein the unit A is represented by the following formula (2): (In the general formula (2), R １ , L, Sp, X － and f are R in the general formula (1), １ , L, Sp, X － and f are selected from the same options as R ６ａis any one selected from the group consisting of an optionally substituted linear, branched or cyclic alkylene group having 1 to 6 carbon atoms; an optionally substituted linear, branched or cyclic alkenylene group having 2 to 6 carbon atoms; an optionally substituted arylene group having 6 to 14 carbon atoms; an optionally substituted heteroarylene group having 4 to 12 carbon atoms; and a direct bond; ６ａ At least one methylene group in R may be substituted with a divalent heteroatom-containing group; ６ｂ are each independently any one selected from the group consisting of an optionally substituted linear, branched or cyclic alkyl group having 1 to 6 carbon atoms; an optionally substituted linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms; an optionally substituted aryl group having 6 to 14 carbon atoms; and an optionally substituted heteroaryl group having 4 to 12 carbon atoms, ６ｂ At least one methylene group in R may be substituted with a divalent heteroatom-containing group; ６ａ and two R ６ｂ two of the f X's bonded to R may form a ring structure with the sulfur atom to which they are bonded, either directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group and a methylene group; － , f R ６ａ , f R ６ｂ , f R 1 , f L and f Sp may be the same or different from each other. [4] The M ＋ The polymer according to any one of [1] to [3], wherein the polymer is represented by the following general formula (3) or the following formula (4): (In the formula (3), R １１ and R １２ are each independently any one selected from the group consisting of an optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; an optionally substituted linear, branched or cyclic alkenyl group having 2 to 12 carbon atoms; an optionally substituted aryl group having 6 to 14 carbon atoms; and an optionally substituted heteroaryl group having 4 to 12 carbon atoms; 1１ , R１２ and any two or more of the aryl groups to which the sulfonium groups are bonded may form a ring structure together with the sulfur atom to which they are bonded, either directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group and a methylene group, 1１ and R １２ At least one methylene group in R may be substituted with a divalent heteroatom-containing group; １３ and R １４ are each independently any one selected from the group consisting of an alkyl group, a hydroxy group, a mercapto group, an alkyleneoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkyleneoxycarbonyl group, an aryloxycarbonyl group, an arylsulfanylcarbonyl group, an arylsulfanyl group, an alkylsulfanyl group, an aryl group, a heteroaryl group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a (meth)acryloyloxy group, a hydroxy(poly)alkyleneoxy group, an amino group, a cyano group, a nitro group, and a halogen atom, and when a carbon atom is present, the number of carbon atoms is 1 to 12, and these may have a substituent; １４ is connected to said R via any one selected from the group consisting of a direct bond, a methylene group, an oxygen atom, a sulfur atom, and a divalent nitrogen atom-containing group. １４ may form a ring structure together with the aryl group to which R is bonded, １５ and R １６ are each independently any one selected from the group consisting of an optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; an optionally substituted linear, branched or cyclic alkenyl group having 2 to 12 carbon atoms; an optionally substituted aryl group having 6 to 14 carbon atoms; and an optionally substituted heteroaryl group having 4 to 12 carbon atoms; １５ and R １６ may be bonded to each other directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom and an alkylene group to form a ring structure, １５ and R１６ At least one methylene group in L may be substituted with a divalent heteroatom-containing group; ２ is any one selected from the group consisting of a direct bond; a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms; an alkenylene group having 2 to 12 carbon atoms; an arylene group having 6 to 14 carbon atoms; a heteroarylene group having 4 to 12 carbon atoms; and groups in which these groups are bonded via an oxygen atom, a sulfur atom, or a divalent nitrogen atom-containing group; ３ is selected from the group consisting of a direct bond, a methylene group, a sulfur atom, a divalent nitrogen-containing group, and an oxygen atom; Y is an oxygen atom or a sulfur atom; h is an integer of 1 to 2; i is an integer of 1 to 3; j is an integer of 0 to 3 when h is 1 and an integer of 0 to 5 when h is 2; k is an integer of 0 to 4 when i is 1, 0 to 6 when i is 2, and 0 to 8 when i is 3; R １１ , R １２ and R １４ and R １４ is replaced by a bond to Sp in the above formula (1), and in the above formula (4), R １１ ~R １６ , L ２ and Y are each independently R in formula (3). １１ ~R １６ , L ２ and Y are each selected from the same options, h is an integer from 1 to 2, i is an integer from 1 to 3, j is an integer from 0 to 4 when h is 1 and from 0 to 6 when h is 2, k is an integer from 0 to 5 when i is 1, from 0 to 7 when i is 2 and from 0 to 9 when i is 3, and L ４ and L ５ and each independently represent any one selected from the group consisting of a direct bond, an alkenylene group having 2 carbon atoms, an alkynylene group having 2 carbon atoms, and a carbonyl group. [5] The polymer according to any one of [1] to [4], further comprising a unit D, wherein the unit D is represented by the following formula (6): (In the above general formula (6), R １ , L, Sp, M ＋ is R in the general formula (1) above. １, L, Sp, M ＋ are selected from the same options as Z － is a monovalent anion.) [6] The polymer according to any one of [1] to [5], wherein the molar ratio of unit D to unit A is 0 to 20. [7] The polymer according to any one of [1] to [6], further comprising unit C, wherein unit C is a unit in which a compound represented by the following general formula (I) or (II) is bonded to an Sp group of the following formula (5) at any position of the compound: (In the general formula (I), R ２ and R ３ are each independently any one selected from the group consisting of a hydrogen atom; an electron donating group; and an electron withdrawing group; E is any one selected from the group consisting of a direct bond; an oxygen atom; a sulfur atom; and a methylene group; R ４ is any one selected from the group consisting of an alkyl group which may have a substituent; and an alkenyl group which may have a substituent; １ is an integer of 0 or 1, and n ４ and n ５ are each an integer of 1 to 2, and n ４ +n ５ is 2 to 4, and n ４ When is 1, n ２ is an integer from 0 to 4, and n ４ When is 2, n ２ is an integer from 0 to 6, ５ When is 1, n ３ is an integer from 0 to 4, and n ５ When is 2, n ３ is an integer from 0 to 6, ２ is 2 or more and R ２ is an electron donating group or an electron withdrawing group, two R ２ may form a ring structure with each other directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group and a methylene group, ３ is 2 or more and R ３ is an electron donating group or an electron withdrawing group, two R ３may form a ring structure with each other directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group and a methylene group. ４ is any one selected from the group consisting of an alkyl group which may have a substituent; and an alkenyl group which may have a substituent; ５ is any one selected from the group consisting of a hydrogen atom; an alkyl group which may have a substituent; and an alkenyl group which may have a substituent; ５ At least one methylene group in R may be substituted with a divalent heteroatom-containing group, ５ is the R ５ may form a ring structure together with the benzene ring to which the hydroxymethylene group having R ６ are each independently any one selected from the group consisting of a hydrogen atom; an electron-donating group; and an electron-withdrawing group; ６ At least one of the n is the electron-donating group; ６ is an integer from 0 to 7, ７ is 1 or 2, and n ７ When is 1, n ６ is an integer from 0 to 5, and n ７ When is 2, n ６ is an integer from 0 to 7, ６ is 2 or more and R ４ is an electron donating group or an electron withdrawing group, two R ４ may form a ring structure with each other directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group, and a methylene group. (In the formula (5), R １ , L and Sp are R in the general formula (1), １, L, and Sp are selected from the same options as those for L and Sp, and * represents a bonding site with the compound represented by general formula (I) or (II). [8] A resist composition containing the polymer according to any one of [1] to [7]. [9] A method for producing a member, comprising: a resist film formation step of forming a resist film on a substrate using the resist composition according to [8]; a photolithography step of exposing the resist film with a particle beam or electromagnetic waves; and a pattern formation step of developing the exposed resist film with a developer to dissolve the exposed areas, thereby obtaining a photoresist pattern.

[10] A method for producing a member according to [9], wherein the developer is an organic solvent.

[11] A method for producing a member according to [9] or

[10] , wherein, in the photolithography step, after exposure to the particle beam or electromagnetic waves, further irradiation is performed with a second active energy ray having lower energy than the particle beam or electromagnetic wave.

[12] A method for producing a member according to any one of [9] to

[11] , wherein the particle beam is an electron beam and the electromagnetic wave is extreme ultraviolet light.

[13] A pattern formation method comprising: a resist film formation step of forming a resist film on a substrate using the resist composition according to [8]; a photolithography step of exposing the resist film using a particle beam or electromagnetic waves; and a pattern formation step of developing the exposed resist film using a developer to dissolve the exposed areas, thereby obtaining a photoresist pattern.

[14] The pattern formation method according to

[13] , wherein the developer is an organic solvent.

[15] The pattern formation method according to

[13] or

[14] , wherein, in the photolithography step, after exposure to the particle beam or electromagnetic waves, a second active energy ray having an energy lower than that of the particle beam or electromagnetic wave is further irradiated.

[0020] When used as a resist composition, the polymer according to one embodiment of the present invention decomposes upon irradiation with particle beams, electromagnetic waves, or the like, thereby converting its polarity, and in addition, the f-valent anion is protonated to generate an acid. This causes the polymer formed via the anion to decompose, eliminating the crosslinked structure between the polymer molecules, thereby changing the solubility of the polymer. Therefore, a resist composition containing the polymer can significantly change its solubility through the decomposition of the polymer in addition to the polarity conversion caused by the decomposition of unit A. Therefore, when a pattern is formed using the polymer according to one embodiment of the present invention, the sensitivity and development contrast characteristics are excellent.

[0021] In the present invention, "particle beams or electromagnetic waves" refers to not only electron beams and extreme ultraviolet rays, but also ultraviolet rays, etc., with electron beams or extreme ultraviolet rays being preferred. In the present invention, "particle beam or electromagnetic wave irradiation" refers to irradiating at least a portion of a polymer with particle beams or electromagnetic waves. Irradiating a portion of a polymer with particle beams or electromagnetic waves excites or ionizes a specific portion of the polymer, generating active species. The active species induces at least one secondary reaction, such as decomposition of a portion of the unit, addition of the active species to the unit, or elimination of hydrogen from the unit, thereby generating radicals or acids. Here, "active species" refers to radical cations, radicals, electrons, etc. In the present invention, "polarity conversion" refers to the direct or indirect change from ionic to nonionic properties due to irradiation with particle beams or electromagnetic waves, thereby improving hydrophobicity. The present invention will be described in detail below, but is not limited thereto.

[0022] <1> Polymer One embodiment of the polymer of the present invention is a polymer that includes a unit A having a specific onium salt structure and generating an acid upon irradiation with a particle beam or electromagnetic wave, and an organometallic compound-containing unit B having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi, and Te.

[0023] (Unit A) The unit A has a specific onium salt structure. Specifically, the onium salt structure undergoes polarity conversion when at least a portion of the polymer is irradiated with particle beams or electromagnetic waves. That is, the unit A is characterized by having an f-valent anion and f units having a cation group corresponding to the f-valent anion, and the f units are bonded together via the f-valent anion. Specific examples include those represented by the following formula (1):

[0024]

[0025] In the above general formula (1), M ＋ is a sulfonium cationic group or an iodonium cationic group.

[0026] L is not particularly limited as long as it can bond the main chain constituting the polymer with the onium salt structure, and in addition to a direct bond, examples include any group selected from the group consisting of a carbonyloxy group, a carbonylamino group, a phenylenediyl group, a naphthalenediyl group, a phenylenediyloxy group, a naphthalenediyloxy group, a phenylenediylcarbonyloxy group, a naphthalenediylcarbonyloxy group, a phenylenediyloxycarbonyl group, and a naphthalenediyloxycarbonyl group, etc. As L, a carbonyloxy group, etc. is preferred from the viewpoint of ease of synthesis.

[0027] Sp is not particularly limited as long as it can serve as a spacer between L and the onium salt, and is, for example, any of a direct bond; an optionally substituted linear, branched, or cyclic alkylene group having 1 to 6 carbon atoms; and an optionally substituted linear, branched, or cyclic alkenylene group having 2 to 6 carbon atoms, and at least one methylene group in Sp may be substituted with a divalent heteroatom-containing group.

[0028] Examples of the linear alkylene group having 1 to 6 carbon atoms for Sp include a methylene group, an ethylene group, an n-propylene group, an n-butylene group, an n-pentylene group, an n-hexylene group, etc. Examples of the branched alkylene group having 1 to 6 carbon atoms for Sp include an isopropylene group, an isobutylene group, a tert-butylene group, an isopentylene group, a tert-pentylene group, an 2-ethylhexylene group, etc.

[0029] Examples of the cyclic alkylene group having 1 to 6 carbon atoms for Sp include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, and a cyclohexylene group. At least one methylene group in Sp may be substituted with a divalent heteroatom-containing group. Examples of the divalent heteroatom-containing group include -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -NHCO-, -CONH-, -NH-CO-O-, -O-CO-NH-, -NH-, -N(R Ｓｐ ) -, -N(Ar Ｓｐ )-, -S-, -SO-, and -SO2-. However, it is preferable that there is no continuous linkage of heteroatoms such as -O-O-, -S-S-, and -O-S-. Examples of Sp in which at least one methylene group is substituted with a divalent heteroatom-containing group include polyalkyleneoxy groups such as 2-methoxyethoxy group, 2-ethoxyethoxy group, 2-(2-methoxyethoxy)ethoxy group, 2-(2-ethoxyethoxy)ethoxy group, 2-methoxypropoxy group, and 3-methoxypropoxy group; polyalkylenethio groups such as 2-methylthioethylthio and 2-ethylthioethylthio group; and polyalkyleneoxythio groups such as 2-methylthioethoxy group and 2-ethoxyethylthio group. However, some aspects of the present invention are not limited thereto. The above R Ｓｐ Examples of Ar include linear, branched, or cyclic alkyl groups having 1 to 12 carbon atoms. Ｓｐ Examples of the alkyl group include aryl groups having 12 or less carbon atoms, such as phenyl and naphthyl groups.

[0030] The substituent that Sp may have (hereinafter also referred to as "first substituent") includes a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom; a hydroxy group; a linear or cyclic alkyl group having 1 to 12 carbon atoms; and a group selected from the group consisting of -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -NHCO-, -CONH-, -NH-CO-O-, -O-CO-NH-, -NH-, -N(R Ｓｐ ) -, -N(Ar Ｓｐ )-, -S-, -SO- and -SO2 － Examples of the divalent heteroatom-containing group include an alkyl group, an aryl group, and a heteroaryl group each having a divalent heteroatom-containing group in the skeleton selected from the group consisting of Ｓｐ and Ar Ｓｐ can be the first substituent. When Sp has the first substituent, the number of carbon atoms of Sp, including the number of carbon atoms of the first substituent, is preferably 1 to 6. Examples of the alkyl group as the first substituent of Sp and the alkyl group containing the divalent heteroatom-containing group in its skeleton include alkyl groups in which the alkylene group of Sp is monovalent. Examples of the aryl group as the first substituent of Sp include the above Ar Ｓｐ Examples of the heteroaryl group as the first substituent of Sp include groups having a skeleton such as furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, and pyrazine. Sp may be a direct bond, but preferably has a spacer structure to facilitate molecular movement. Preferred examples include an alkylene group, an alkyleneoxy group, and an alkylenecarbonyloxy group.

[0031] R 1 is any one selected from the group consisting of a hydrogen atom; a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched, or cyclic alkenyl group having 2 to 6 carbon atoms; 1 At least one hydrogen atom in the alkyl group and alkenyl group in R may be substituted with a substituent. １ The substituent that may be possessed by may be the same as that described above for the first substituent.

[0032] R1 Examples of the linear alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. 1 Examples of the branched alkyl group having 1 to 6 carbon atoms include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a tert-pentyl group, and a 2-ethylhexyl group. 1 Examples of the cyclic alkyl group having 1 to 6 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

[0033] R 1 Examples of the linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms include the linear alkyl group, branched alkyl group and cyclic alkyl group shown above in which at least one carbon-carbon single bond has been replaced with a carbon-carbon double bond. 1 The alkyl group and alkenyl group may be fluorinated alkyl groups and fluorinated alkenyl groups in which at least one hydrogen atom in the alkyl group and alkenyl group is substituted with a fluorine atom. As the fluorinated alkyl group, a trifluoromethyl group or the like is preferable. All hydrogen atoms may be substituted with the first substituent. １ When R has the first substituent, １ The number of carbon atoms of the first substituent is preferably 1 to 6, including the number of carbon atoms of the first substituent.

[0034] The unit A is preferably R １ is a hydrogen atom or a linear alkyl group, and L is a carbonyloxy group, a carbonylamino group, or a phenylenediyl group. In addition, as the unit A, L is a carbonyloxy group or a carbonylamino group, Sp is a direct bond, and R １ is a methyl group, and the methyl group has at least one of an alkyl group having 1 to 4 carbon atoms, a halogen atom, and an aryl group among the first substituents, from the viewpoint of LWR. 1Particularly preferred examples of the alkyl group include an ethyl group, an isopropyl group, a butyl group, a halogenated methyl group (such as a fluoromethyl group, a chloromethyl group, a bromomethyl group, or an iodomethyl group), and a benzyl group.

[0035] M ＋ is a sulfonium cation group or an iodonium cation group having a bond bonded to Sp, and specific examples thereof include those represented by the following general formulae (a1) and (a2).

[0036]

[0037] In the polymer according to one embodiment of the present invention, the unit A is preferably one represented by the following formula (2).

[0038]

[0039] In the above general formula, R 6ａ is any one selected from the group consisting of an optionally substituted linear, branched, or cyclic alkylene group having 1 to 6 carbon atoms; an optionally substituted linear, branched, or cyclic alkenylene group having 2 to 6 carbon atoms; an optionally substituted arylene group having 6 to 14 carbon atoms; an optionally substituted heteroarylene group having 4 to 12 carbon atoms; and a direct bond. 6ａ Examples of the linear, branched, or cyclic alkylene group of R include the same alkylene groups as those of Sp. 6ａ Examples of the linear, branched or cyclic alkenylene group of include the same as the alkenylene group of Sp.

[0040] R 6ａ Examples of the arylene group having 6 to 14 carbon atoms include a phenylene group and a naphthylene group. 6ａ Examples of the heteroarylene group having 4 to 12 carbon atoms include divalent groups having a skeleton such as furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, pyrazine, indole, purine, quinoline, isoquinoline, chromene, thianthrene, dibenzothiophene, phenothiazine, phenoxazine, xanthene, acridine, phenazine, and carbazole. 6ｂThe alkyl group, alkenyl group, aryl group and heteroaryl group in the above R 6ａ Examples of the alkylene group, alkenylene group, arylene group and heteroarylene group are those in which the group is monovalent.

[0041] R 6ａ and R 6ｂ Examples of the substituent of R include the same substituent as the first substituent that Sp may have. ６ａ and R ６ｂ When R has the first substituent, ６ａ and R ６ｂ The number of carbon atoms in R is preferably 1 to 6, including the number of carbon atoms in the first substituent. 6ａ and two R 6ｂ Any two of these may form a ring structure together with the sulfur atom to which they are bonded, either directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen-atom-containing group, and a methylene group. Examples of the divalent nitrogen-atom-containing group include those containing a nitrogen atom among the divalent heteroatom-containing groups, and specific examples thereof include -NHCO-, -CONH-, -NH-CO-O-, -O-CO-NH-, -NH-, -N(R Ｓｐ )- and -N(Ar Ｓｐ ) - etc.

[0042] M ＋ The sulfonium cation group as R is, for example, a monovalent group having a bond bonded to the above Sp at any position in the structure shown below. 6ａ and R 6ｂ The moiety corresponding to may have the above-mentioned substituent.

[0043]

[0044] The anion of unit A is an f-valent anion. Specifically, R(X - ) ｆR is an f-valent anion represented by the formula: R is an f-valent hydrocarbon group having 1 to 6 carbon atoms, and at least one hydrogen atom in R may be substituted with a substituent (hereinafter also referred to as a "second substituent"). When f is 2, examples of the divalent hydrocarbon group include an alkylene group, an arylene group, and a heteroarylene group. When f is 3, examples of the trivalent hydrocarbon group include the above-mentioned divalent substituents made trivalent. In addition to the above-mentioned first substituent, examples of the above-mentioned second substituent include an amino group. As the above-mentioned second substituent, a fluorine atom or the like is preferred.

[0045] X － is a monovalent anion group, and may be any one selected from the group consisting of alkyl sulfate anion, aryl sulfate anion, alkyl sulfonate anion, aryl sulfonate anion, alkyl carboxylate anion, aryl carboxylate anion, dialkylsulfonylimide anion, trialkylsulfonate methide anion, tetrakisphenylborate anion, etc. At least one hydrogen atom of the alkyl group and aryl group in X- may be substituted with the second substituent. When there are f X's in an f-valent anion, - R and X may be the same or different. － When the group contains a methylene group, at least one of the methylene groups may be substituted with the above-mentioned divalent heteroatom-containing group. Examples of the divalent heteroatom-containing group include the same as the divalent heteroatom-containing group in Sp.

[0046] The alkyl sulfate anion, the alkyl sulfonate anion, the dialkylsulfonylimide anion, and the trialkylsulfonate methide anion preferably have 1 to 12 carbon atoms. The aryl sulfate anion and the aryl sulfonate anion preferably have 4 to 12 carbon atoms. The alkyl carboxylate anion preferably has 2 to 12 carbon atoms. The aryl carboxylate anion preferably has 5 to 12 carbon atoms. The tetrakisphenylborate anion preferably has 25 to 30 carbon atoms.

[0047] The unit A has an f-valent anion. Specific examples of the f-valent anion include, but are not limited to, the following:

[0048]

[0049] In one embodiment of the polymer of the present invention, the M ＋ From the viewpoint of sensitivity, it is also preferable that M is represented by the following general formula (3) or the following formula (4). ＋ has an acetal moiety or a thioacetal moiety, and thus when, in a photolithography process, after exposure to the particle beam or electromagnetic wave, the compound is further irradiated with a second active energy ray having lower energy than the particle beam or electromagnetic wave, decomposition of the unit A is promoted, thereby resulting in high sensitivity.

[0050]

[0051] Specifically, M of the onium salt of the unit A ＋ Since the onium salt has an acetal moiety or a thioacetal moiety, it does not have significant absorption of the second active energy ray, such as ultraviolet light or visible light. On the other hand, the onium salt is converted into a ketone derivative by deprotection of the acetal moiety or the thioacetal moiety due to the acid generated by the first active energy ray, such as a particle beam or electromagnetic wave, without impairing its function as a photoacid generator. The ketone derivative has absorption of the first active energy ray and the second active energy ray.

[0052] Therefore, the above M ＋In one embodiment of the present invention, the polymer is represented by either the general formula (3) or the general formula (4), and when used as a resist composition, upon irradiation with a first energy ray such as a particle beam or electromagnetic wave, the onium salt structure of the unit A decomposes, causing a large polarity change from ionic to nonionic, thereby generating an acid. Furthermore, the onium salt structure of the unit A in the composition irradiated with the first active energy ray undergoes a structural change in response to the acid, resulting in conversion to a ketone derivative that absorbs the second active energy ray. Irradiating the composition containing the ketone derivative with a second active energy ray such as ultraviolet light or visible light generates an acid with high efficiency, resulting in the composition exhibiting high sensitivity and excellent pattern characteristics such as LWR. For this reason, the polymer of one embodiment of the present invention is preferably used in a two-stage irradiation process in which, after irradiation with the first active energy ray, the portion irradiated with the first active energy ray is then irradiated with the second active energy ray. The ketone derivative is generated in the resist film at the irradiated portion irradiated with the first active energy ray, and therefore, by further irradiating the resist film with the second active energy ray, the amount of acid generated can be increased at the irradiated portion irradiated with the first active energy ray.

[0053] In the above formula (3), R １１ and R １２ are each independently any one selected from the group consisting of an optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; an optionally substituted linear, branched or cyclic alkenyl group having 2 to 12 carbon atoms; an optionally substituted aryl group having 6 to 14 carbon atoms; and an optionally substituted heteroaryl group having 4 to 12 carbon atoms. 1１ and R １２ At least one methylene group in the group may be substituted with a divalent heteroatom-containing group. Examples of the divalent heteroatom-containing group include the same as the divalent heteroatom-containing group in Sp.

[0054] The above R １１ , R １２Any two or more of the aryl groups to which the sulfonium group is bonded may form a ring structure together with the sulfur atom to which they are bonded, either directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen-containing group, and a methylene group. Examples of the divalent nitrogen-containing group include divalent groups containing a nitrogen atom among the divalent heteroatom-containing groups.

[0055] R １１ and R １２ The substituent in (hereinafter also referred to as "third substituent") may be a hydroxy group, a cyano group, a mercapto group, a carboxy group, an alkyl group (-R e ), an alkoxy group (—OR e ), acyl group (—COR e ), an alkoxycarbonyl group (—COOR e ), aryl group (-Ar), aryloxy group (-OAr), amino group, alkylamino group (-NHR e ), a dialkylamino group (—N(R e ) ２ ), arylamino group (-NHAr), diarylamino group (-N(Ar) ２ ), N-alkyl-N-arylamino group (—NR e Ar) a phosphino group, a silyl group, a halogen atom, a trialkylsilyl group (—Si—(R e ) ３ a silyl group in which at least one alkyl group of the trialkylsilyl group is substituted with Ar; an alkylsulfanyl group (—SR e ) and arylsulfanyl group (—SAr), but are not limited to these. e and Ar are described below.

[0056] The R in the third substituent eis preferably an alkyl group having 1 or more carbon atoms. It is more preferably one having 20 or less carbon atoms. Specific examples of alkyl groups having 1 or more carbon atoms include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, and n-decyl groups; branched alkyl groups such as isopropyl, isobutyl, tert-butyl, isopentyl, tert-pentyl, and 2-ethylhexyl groups; alicyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantan-1-yl, adamantan-2-yl, norbornan-1-yl, and norbornan-2-yl groups; silyl-substituted alkyl groups in which one of the hydrogen atoms in these groups is substituted with a trialkylsilyl group such as a trimethylsilyl group, a triethylsilyl group, and a dimethylethylsilyl group; and alkyl groups in which at least one of the hydrogen atoms in these groups is substituted with a cyano group, a fluoro group, or the like. The carbon-carbon single bond in the alkyl group may be replaced with a carbon-carbon double bond.

[0057] Ar in the third substituent is preferably an aryl group or a heteroaryl group. The heteroaryl group is preferably an aryl group containing one or more heteroatoms in the ring structure. Specific examples of the aryl group or heteroaryl group include a phenyl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a naphthyl group, an anthryl group, a phenanthrenyl group, a pentalenyl group, an indenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a heptalenyl group, a naphthacenyl group, a pyrenyl group, a chrysenyl group, a tetracenyl group, a furanyl group, a thienyl group, a pyranyl group, a sulfanylpyranyl group, a pyrrolyl group, an imidazolinyl group, ... phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl group, a phenyl Preferred examples thereof include those having 20 or less carbon atoms, such as a zoyl group, oxazolyl group, thiazolyl group, pyrazoyl group, pyridyl group, isobenzofuranyl group, benzofuranyl group, isochromenyl group, chromenyl group, indolyl group, isoindolyl group, benzimidazoyl group, xanthenyl group, aquadinyl group, carbazoyl group, furan group, thiophene group, pyrrole group, imidazole group, pyran group, pyridine group, pyrimidine group, and pyrazine group.

[0058] The third substituent may be a group further having a third substituent, and the group may further have a second substituent. １１ and R １２ When the alkyl group or the like has the third substituent, R １１ and R １２ The number of carbon atoms in R is preferably 1 to 20, including the number of carbon atoms in the third substituent. When the third substituent further has a third substituent, or when the above group further has a third substituent, １１ and R １２ The number of carbon atoms in R is preferably 1 to 20, including the number of third substituents. 1１ and R １２ has a third substituent, and the third substituent further has a third substituent, 1１ and R １２ Examples of the alkyl group include groups having a glycol chain or a thioglycol chain.

[0059] R １３ and R １４ are each independently any one selected from the group consisting of an alkyl group, a hydroxy group, a mercapto group, an alkyleneoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkyleneoxycarbonyl group, an aryloxycarbonyl group, an arylsulfanylcarbonyl group, an arylsulfanyl group, an alkylsulfanyl group, an aryl group, a heteroaryl group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a (meth)acryloyloxy group, a hydroxy(poly)alkyleneoxy group, an amino group, a cyano group, a nitro group, and a halogen atom, and when having carbon, the number of carbon atoms is 1 to 12, and these may have a substituent (hereinafter also referred to as a "fourth substituent").

[0060] One R １４ is connected to said R via any one selected from the group consisting of a direct bond, a methylene group, an oxygen atom, a sulfur atom, and a divalent nitrogen atom-containing group. １４ may form a ring structure together with the aryl group to which they are bonded.

[0061] R １３ and R １４ Examples of the fourth substituent in the formula (I) include the same as the fourth substituent described above.

[0062] R １３ and R １４ When the alkyl group or the like has the fourth substituent, R １３ and R １４ The number of carbon atoms of the fourth substituent is preferably 1 to 20, including the number of carbon atoms of the fourth substituent.

[0063] R １３ and R １４ When the alkyl group R has an alkyl group, at least one of the methylene groups of the alkyl group may be substituted with the above-mentioned divalent heteroatom-containing group. However, it is preferable that the alkyl group does not have a continuous bond of heteroatoms such as -O-O-, -S-S-, and -O-S-. When the alkyl group R has an alkyl group, at least one of the methylene groups may be substituted with the above-mentioned divalent heteroatom-containing group. １３ and R １４ Examples of the alkyl group include polyalkyleneoxy groups such as a 2-methoxyethoxy group, a 2-ethoxyethoxy group, a 2-(2-methoxyethoxy)ethoxy group, a 2-(2-ethoxyethoxy)ethoxy group, a 2-methoxypropoxy group, and a 3-methoxypropoxy group; polyalkylenethio groups such as a 2-methylthioethylthio group and a 2-ethylthioethylthio group; and polyalkyleneoxythio groups such as a 2-methylthioethoxy group and a 2-ethoxyethylthio group. However, some aspects of the present invention are not limited thereto.

[0064] Preferred R １４ From the viewpoint of acid generation efficiency, R is preferably an arylsulfanyl group, an alkylsulfanyl group, an amino group having the fourth substituent, a hydroxyl group, an alkoxy group, or the like, because the absorption of the second actinic energy ray increases when it is converted into a ketone derivative. １４ is an arylsulfanyl group, an alkylsulfanyl group, an amino group having the fourth substituent, a hydroxy group, or an alkoxy group; １４is preferably at the para-position relative to the bonding position of the acetal moiety or thioacetal moiety. When these substituents are at the para-position, the absorption of the second actinic ray tends to be large when the derivative becomes a ketone derivative.

[0065] R １５ and R １６ are each independently selected from the group consisting of an optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; an optionally substituted linear, branched or cyclic alkenyl group having 2 to 12 carbon atoms; an optionally substituted aryl group having 6 to 14 carbon atoms; and an optionally substituted heteroaryl group having 4 to 12 carbon atoms. １５ and R １６ may be bonded to each other directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom and an alkylene group to form a ring structure, １５ and R １６ At least one methylene group therein may be substituted with the above divalent heteroatom-containing group.

[0066] R １５ and R １６ The substituent in the formula (I) may be the same as the third substituent.

[0067] L ２ is preferably selected from the group consisting of a direct bond; a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms; an alkenylene group having 2 to 12 carbon atoms; an arylene group having 6 to 14 carbon atoms; a heteroarylene group having 4 to 12 carbon atoms; and groups in which these groups are bonded via an oxygen atom, a sulfur atom, or the above-mentioned divalent nitrogen atom-containing group.

[0068] L ３ is preferably selected from the group consisting of a direct bond, a methylene group, a sulfur atom, the above-mentioned divalent nitrogen atom-containing group, and an oxygen atom.

[0069] Y is an oxygen atom or a sulfur atom. h is an integer of 1 or 2, and i is an integer of 1 to 3. j is an integer of 0 to 3 when h is 1, and an integer of 0 to 5 when h is 2. k is an integer of 0 to 4 when i is 1, 0 to 6 when i is 2, and 0 to 8 when i is 3.

[0070] In one embodiment of the present invention, the onium salt structure in unit A is preferably a monocation. Even when h in the above general formula (3) and the above general formula (4) is 1 to 2, the sulfonium cation is preferably a monocation. ２ In the case where h is 1 or 2, L replaces any one hydrogen atom on the arylene represented by the arrow in the following general formulas (3-a) and (3-b). ２ Similarly, when h is 1 or 2, any one hydrogen atom on the arylene indicated by the arrow in the following general formulas (4-a) to (4-b) is replaced.

[0071]

[0072] R １１ , R １２ and R １４ and R １４ In the above formula (4), the hydrogen atom on the aryl ring to which R is bonded is replaced by a bond to Sp in the above formula (1). １１ ~R １６ , L ２ and Y are independently R in the formula (3) １１ ~R １６ , L ２ and Y are selected from the same options. h is an integer of 1 to 2, and i is an integer of 1 to 3. j is an integer of 0 to 4 when h is 1, and an integer of 0 to 6 when h is 2. k is an integer of 0 to 5 when i is 1, and an integer of 0 to 7 when i is 2, and an integer of 0 to 9 when i is 3. L ４ and L ５ are each independently any one selected from the group consisting of a direct bond, an alkenylene group having 2 carbon atoms, an alkynylene group having 2 carbon atoms, and a carbonyl group.

[0073] In one embodiment of the present invention, the cation (M ＋ ) can be exemplified by those having the sulfonium cation shown below. The wavy line in the sulfonium cation shown below indicates the bonding site with Sp in the above formula (1), and when there are multiple wavy lines in the same structure, it is preferable that one of them bonds to the above Sp. However, some aspects of the present invention are not limited to this.

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080] The anion of the unit A is not particularly limited as long as it is an f-valent anion, but from the viewpoint of improving development contrast in photoresist pattern formation, specific examples include a tetrafluorosuccinate dianion, a hexafluoroglutarate dianion, an octafluoroadipic acid dianion, a 2,2-difluoro(2-oxysulfonyl)acetic acid dianion, an L-cysteine ​​acid dianion, an oxaloacetic acid dianion, a sulfosuccinate dianion, a sulfosuccinate trianion, and a citrate trianion.

[0081] In one embodiment of the present invention, the polymer may contain two or more types of the unit A. For example, it is preferable to use one as the photoacid generator unit A and the other as the photodegradable base unit A. It is preferable to use the photodegradable base unit A having a lower acid strength than the photoacid generator unit A in combination with the photoacid generator unit A. In addition, when the polymer contains two or more types of the unit A, the onium salt structural moiety is the same and R １ Units having different substituents such as , , and L may also be used.

[0082] The onium salt structure containing the unit A according to one embodiment of the present invention has a molar absorption coefficient at 365 nm of 1.0×10 ５ cm ２ / mol, and preferably less than 1.0 × 10 ４ cm ２ In addition, when the onium salt structure contained in unit A according to some embodiments of the present invention has an acetal moiety or a thioacetal moiety, the ketone derivative obtained by deprotecting the acetal moiety or the thioacetal moiety has a molar absorption coefficient at 365 nm of less than 1.0 × 10 ５ cm ２ / mol or more, and preferably 1.0 × 10 ６ cm ２ / mol or more. The molar absorption coefficient at 365 nm of the ketone derivative is preferably 5 times or more, more preferably 10 times or more, and even more preferably 20 times or more, of the molar absorption coefficient at 365 nm of the onium salt structure contained in unit A according to one embodiment of the present invention. In order to achieve the above characteristics, an onium salt having a cation represented by formula (3) or (4) may be used.

[0083] (Unit B) In one embodiment of the present invention, the polymer further contains an organometallic compound-containing unit (hereinafter also referred to as "unit B") having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi, and Te. The metal atom contained in unit B is not particularly limited as long as it has high absorption for EUV or electron beams, and may be an atom of Groups 10 to 16 of the Periodic Table in addition to the above metal atoms. Unit B is preferably a unit in which an alkyl and aryl tin, alkyl and aryl antimony, alkyl and aryl germane, or alkyl and aryl bismuthine structure is bonded to the * portion of formula (5) below at any position in the structure. Formula (5) will be described later in detail in the section on unit C. Unit B has a high secondary electron generation efficiency upon EUV irradiation, and can increase the decomposition efficiency of unit A. Unit B is not particularly limited as long as it contains the above metal atom having high EUV absorption, but specific examples include the units shown below.

[0084]

[0085] In the above general formula, R 12a Each of R is preferably independently any one selected from the group consisting of a hydrogen atom and an alkyl group. 12a The alkyl group as may have a substituent. Examples of the alkyl group include a linear or branched alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an isopropyl group, an n-isopropyl group, a sec-butyl group, a tert-butyl group, an n-butyl group, and a pentyl group. Examples of the substituent that the alkyl group may have include a hydroxy group, a sulfonyloxy group, an alkylcarbonyloxy group, an alkyloxycarbonyl group, a cyano group, a methoxy group, and an ethoxy group. In the above formula, when two or more R 12a is not a hydrogen atom, 12a Two R are not hydrogen atoms 12a may form a ring structure directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group, and a methylene group. 12ｂmay form a ring structure directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group, and a methylene group. 9 is an integer from 0 to 4.

[0086] In the above general formula, R 12ｂ is any one selected from the group consisting of an optionally substituted linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; an optionally substituted linear, branched, or cyclic alkenyl group having 2 to 6 carbon atoms; an optionally substituted aryl group having 6 to 14 carbon atoms; an optionally substituted heteroaryl group having 4 to 12 carbon atoms; and a direct bond. 12ｂ The straight-chain, branched or cyclic alkyl group of R 2ｂ The alkyl groups are the same as those in the alkyl groups of R 12ｂ The straight-chain, branched or cyclic alkenyl group of R 2ｂ Examples of the alkenyl group include the same as those of the alkenyl group shown above.

[0087] R 12ｂ The aryl group having 6 to 14 carbon atoms includes the above-mentioned R 2ｂ The aryl groups are the same as those of R 12ｂ The heteroaryl group having 4 to 12 carbon atoms includes the above-mentioned R 2ｂ The heteroaryl groups of two or more R 12a may form a ring structure directly by a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group, and a methylene group. 12ｂ Any two of R may be bonded to each other to form a ring structure together with the metal atom to which they are bonded. 12a and R 12ｂ Examples of the substituent that may be possessed by Sp include the same as the first substituent that may be possessed by Sp.

[0088] The unit B is preferably R １is a hydrogen atom or a linear alkyl group, and L is a carbonyloxy group or a phenylenediyl group. Also, as the unit B, L is a carbonyloxy group or a carbonylamino group, Sp is a direct bond, and R １ is a methyl group, and the methyl group has at least one of an alkyl group having 1 to 4 carbon atoms, a halogen atom, and an aryl group among the first substituents, which is preferable from the viewpoint of LWR. 1 Particularly preferred examples of the alkyl group include an ethyl group, an isopropyl group, a butyl group, a halogenated methyl group (such as a fluoromethyl group, a chloromethyl group, a bromomethyl group, or an iodomethyl group), and a benzyl group.

[0089] Specific examples of unit B include units composed of monomers such as 4-vinylphenyl-triphenyltin, 4-vinylphenyl-tributyltin, 4-isopropenylphenyl-triphenyltin, 4-isopropenylphenyl-trimethyltin, trimethyltin acrylate, tributyltin acrylate, triphenyltin acrylate, trimethyltin methacrylate, tributyltin methacrylate, triphenyltin methacrylate, 4-vinylphenyl-diphenylantimony, 4-isopropenylphenyl-diphenylantimony, 4-vinylphenyl-triphenylgermane, 4-vinylphenyl-tributylgermane, 4-isopropenylphenyl-triphenylgermane, and 4-isopropenylphenyl-trimethylgermane. By including unit B in the polymer, it becomes possible to improve the efficiency of secondary electron generation when irradiated with particle beams or electromagnetic waves. In one embodiment of the present invention, the polymer may contain two or more types of unit B.

[0090] (Unit C) The polymer of one embodiment of the present invention further has unit C, and it is preferable that the unit C is a unit in which a compound represented by the following general formula (I) or (II) is bonded to an Sp group of the following formula (5) at any position of the compound:

[0091]

[0092] The unit C is preferably, for example, a unit in which a compound represented by general formula (I) or (II) is bonded to an Sp group of formula (5) at any position of the compound: The polymer containing unit C has improved hydrophobicity due to the elimination of the hydroxyl group by the action of the acid generated by decomposition of unit A, thereby enabling an improvement in development contrast.

[0093]

[0094] In the above formula (5), R 1 , L and Sp are R in the general formula (1) 1 , L and Sp.

[0095] In the above general formula (I), R 2 and R 3 are each independently any one selected from the group consisting of a hydrogen atom; an electron-donating group; and an electron-withdrawing group. 2 and R 3 It is preferable that at least one of R is the electron-donating group, since this improves the acid reactivity. E is preferably any one selected from the group consisting of a direct bond, an oxygen atom, a sulfur atom, and a methylene group. ４ is any one selected from the group consisting of a hydrogen atom; an alkyl group which may have a substituent; and an alkenyl group which may have a substituent. ４ The alkyl group and alkenyl group in R １ By having hydrogen at the β-position of the hydroxyl group, a dehydration reaction occurs efficiently within the molecule due to the action of an acid, improving hydrophobicity and improving development contrast. ４ Preferred examples of the alkyl group include a primary alkyl group, a secondary alkyl group, a primary alkenyl group, and a secondary alkenyl group.

[0096] n 1 is preferably an integer of 0 or 1. ４ and n ５ are integers of 1 to 2. ４ +n ５ is preferably 2 to 4. ４ When is 1, n ２is preferably an integer of 0 to 4. ４ When is 2, n ２ is preferably an integer of 0 to 6. ５ When is 1, n ３ is preferably an integer of 0 to 4. ５ When is 2, n ３ is preferably an integer of 0 to 6. ２ is 2 or more and R 2 is an electron donating group or an electron withdrawing group, two R 2 may form a ring structure with each other directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group, and a methylene group. 3 is 2 or more and R 3 is an electron donating group or an electron withdrawing group, two R 3 may form a ring structure with each other directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group and a methylene group. ６ａ Examples of the divalent nitrogen atom-containing group include the same as the divalent nitrogen atom-containing group in the above formula.

[0097] In the above general formula (II), R ６ are each independently any one selected from the group consisting of a hydrogen atom; an electron-donating group; and an electron-withdrawing group. ６ At least one of R is preferably an electron-donating group, since this improves acid reactivity. ５ is any one selected from the group consisting of a hydrogen atom; an alkyl group which may have a substituent; and an alkenyl group which may have a substituent; ５ At least one methylene group in R may be substituted with a divalent heteroatom-containing group. ５ is the R ５ may form a ring structure together with the benzene ring to which the hydroxymethylene group having the formula:

[0098] R ５The alkyl group of R includes a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms. 6ｂ The alkyl groups shown in the above can be exemplified by the same alkyl groups as those shown in the above. ５ Examples of the substituent that Sp has include the same as the first substituent that Sp has.

[0099] n ６ is preferably an integer of 0 to 7. ７ is preferably 1 or 2. ７ When n is 1, n6 is preferably an integer of 0 to 5. ７ When is 2, n ６ is preferably an integer of 0 to 7.

[0100] n 6 is 2 or more and R 4 is an electron donating group or an electron withdrawing group, two R 4 may form a ring structure with each other directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group and a methylene group. ６ａ Examples of the divalent nitrogen atom-containing group include the same as the divalent nitrogen atom-containing group in the above formula.

[0101] R ２ , R ３ and R ６ The electron donating group in ａ ), the alkyl group (—R ａ an alkenyl group in which at least one carbon-carbon single bond of the above-mentioned alkyl group (—OR ) is replaced with a carbon-carbon double bond; and an alkoxy group (—OR ) bonded at the ortho or para position relative to the position of the aromatic ring to which the methine carbon atom to which the hydroxyl group is bonded is bonded. ａ ) and alkylthio groups (—SR ａ ); etc.

[0102] The above R ａis preferably an alkyl group having 1 or more carbon atoms. Specific examples of the alkyl group having 1 or more carbon atoms include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, and n-decyl groups; branched alkyl groups such as isopropyl, isobutyl, tert-butyl, isopentyl, tert-pentyl, and 2-ethylhexyl groups; cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantan-1-yl, and adamantane-2-yl groups; Preferred examples of the R include alicyclic alkyl groups such as norbornan-1-yl, norbornan-2-yl, and the like; silyl-substituted alkyl groups in which one of the hydrogen atoms in these groups is substituted with a trialkylsilyl group such as a trimethylsilyl group, a triethylsilyl group, and a dimethylethylsilyl group; and alkyl groups in which at least one of the hydrogen atoms on a carbon atom that is not directly bonded to the aromatic ring in the compound (I) or (II) is substituted with a cyano group, a fluoro group, or the like. ａ Preferably, has 4 or less carbon atoms.

[0103] R ２ , R ３ and R ６ Examples of the electron-withdrawing group include —C(═O)R １７ａ (R １７ａ represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms which may have a substituent; １７ｂ (R １７ｂ represents an aryl group having 6 to 14 carbon atoms which may have a substituent; １７ａ ;-SO2R １７ａ ;-SO2R １７ｂ nitro group; nitroso group, trifluoromethyl group, -OR substituted at the meta position relative to the hydroxyl group １７ａ -OR substituted at the meta position relative to the hydroxyl group １７ｂ -SR substituted at the meta position relative to the hydroxyl group １７ａ -SR substituted at the meta position relative to the hydroxyl group １７ｂ ; and the above -C(=O)R １７ａ , -C(=O)OR １７ａ , -SO2R １７ａ and -SR１７ａ a group in which at least one carbon-carbon single bond in R is replaced with a carbon-carbon double bond or a group in which at least one carbon-carbon single bond in R is replaced with a carbon-carbon triple bond; １７ａ and R １７b Examples of the substituent that may be possessed by Sp include the same as the first substituent that may be possessed by Sp.

[0104] R in the above general formula (I) or (II) 4 and R ５ The substituents in R are the same as those in the first substituent group. ２ , R ３ , R ４ , R ５ and R ６ When each of these has a substituent, it preferably has 1 to 14 carbon atoms including the substituent.

[0105] Specific examples of the compounds represented by the above general formula (I) or (II) include those shown below.

[0106]

[0107] One embodiment of the polymer of the present invention is an embodiment in which either of the compounds represented by the general formula (I) or (II) is contained in the polymer as unit C bonded to the * portion of formula (5) at any position of the compound. In this case, the position of bonding to the * portion of formula (5) is R 2 , R 3 and R ６ For example, in the case of the compound represented by the above general formula (I), R 2 It is preferable that one of the H's is replaced with a bond bonded to the * moiety in the formula (5).

[0108] The unit C is preferably R １ is a hydrogen atom or a linear alkyl group, and L is a carbonyloxy group, a carbonylamino group, or a phenylenediyl group. In addition, as the unit C, L is a carbonyloxy group or a carbonylamino group, Sp is a direct bond, and R １is a methyl group, and the methyl group has at least one of an alkyl group having 1 to 4 carbon atoms, a halogen atom, and an aryl group among the first substituents, which is preferable from the viewpoint of LWR. 1 Particularly preferred examples of the unit C include an ethyl group, an isopropyl group, a butyl group, a halogenated methyl group (e.g., a fluoromethyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group), a benzyl group, etc. In one embodiment of the present invention, the polymer may have two or more types of the unit C.

[0109] (Unit D) The resist composition according to one embodiment of the present invention is characterized in that an intramolecular crosslinking reaction occurs upon irradiation with particle beams or electromagnetic waves. Therefore, the resist composition may contain a unit D having an onium salt structure other than unit A. The unit D may be a unit represented by the following formula (6):

[0110]

[0111] In the above general formula (6), R １ , L, Sp, M ＋ is R in the general formula (1) above. １ , L, Sp, M ＋ are selected from the same options as Z － is a monovalent anion.

[0112] Z － Examples of the anion include an alkyl sulfate anion, an aryl sulfate anion, an alkyl sulfonate anion, an aryl sulfonate anion, an alkyl carboxylate anion, an aryl carboxylate anion, a tetrafluoroborate anion, a hexafluorophosphonate anion, a dialkylsulfonylimide anion, a trialkylsulfonate methide anion, a tetrakisphenylborate anion, a hexafluoroantimonate anion, a monovalent metal oxonium anion, and a hydrogen acid anion containing the same. － At least one hydrogen atom of the alkyl group and aryl group in Z may be substituted with a fluorine atom. －At least one methylene group in the alkyl group in the above may be substituted with the above divalent heteroatom-containing group. － The total number of carbon atoms in the anion is preferably 0 to 20, more preferably 0 to 10. The metal oxonium anion is, for example, NiO ２ － and SbO ３ － Also, VO ４ ３－ , SeO ３ ２－ , SeO ４ ２－ , MoO ４ ２－ , SnO ３ ２－ , TeO ３ ２－ , TeO ４ ２－ , TaO ３ ２－ and W.O. ４ ２－ For divalent to trivalent ones such as H ＋ The valence may be made monovalent by appropriately adding a sulfonium ion, an iodonium ion, or a monovalent or divalent metal cation. The monovalent or divalent metal cation may be a common one, for example, Na+, Sn 2＋ , Ni 2＋ etc.

[0113] In one embodiment of the present invention, the polymer may contain two or more types of the unit D.

[0114] In one embodiment of the present invention, the polymer further comprises unit D, which allows the crosslink density of unit A to be adjusted, and the polymer further comprising unit D has the effect of exhibiting excellent solubility in a resist composition.

[0115] (Other Units) In addition to the above units A to D, the polymer in one embodiment of the present invention may also have the following units E to K, etc. Unit E: a unit having an aryloxy group at the portion * of the above formula (5) Unit F: a unit having a radical-generating structure containing at least one multiple bond at the portion * of the above formula (5) Unit G: a unit having a structure containing a halogen atom at the portion * of the above formula (5) Unit H: a unit having a skeleton containing an ether group, lactone skeleton, ester group, hydroxy group, epoxy group, glycidyl group, oxetanyl group, etc. at the portion * of the above formula (5) Unit I: a unit having a skeleton having an alcoholic hydroxy group at the portion * of the above formula (5) Unit J: a unit having a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched, or cyclic alkenyl group having 2 to 6 carbon atoms at the portion * of the above formula (5) Unit K: a unit having a structure containing a silicon atom at the portion * of the above formula (5)

[0116] The units E to K are different from the units A to D and are different from each other. Specific examples of the units E to K include the units disclosed in WO2022 / 39212.

[0117] (Polymer) In one embodiment of the present invention, the polymer preferably has, relative to the unit A, a molar ratio of the unit B of 0.2 to 5, a molar ratio of the unit C of 0 to 3, and a molar ratio of the unit D of 0 to 20, more preferably 1 to 10, and even more preferably 2 to 5. It is preferable that each of the other units E to K is 0 to 2.

[0118] The unit A preferably accounts for 5 to 50 mol %, more preferably 10 to 20 mol %, of the total units of the polymer. The unit B preferably accounts for 10 to 90 mol %, more preferably 30 to 50 mol %. The unit D preferably accounts for 10 to 50 mol %, more preferably 20 to 40 mol %. In one embodiment of the present invention, the polymer can be obtained by using the monomer components constituting each of the above units as raw materials and polymerizing them by a conventional method so as to achieve the above-mentioned blending ratio. In another embodiment of the present invention, the polymer can be obtained by first synthesizing a polymer (referred to as a "precursor polymer") containing a unit having an onium salt structure with a monovalent anion, and then salt-exchanging the precursor polymer with a salt having an f-valent anion to salt-exchange the monovalent anion of the onium salt structure with the desired f-valent anion, thereby obtaining a polymer containing the unit A. In this salt-exchange, all monovalent anions may be salt-exchanged to f-valent anions, or a portion of the monovalent anions may be left. By salt-exchanging in such a way as to leave a portion of the monovalent anions, a polymer containing unit D having an onium salt structure other than unit A can be obtained.

[0119] <2> Resist Composition The resist composition of one embodiment of the present invention is characterized by containing the above-mentioned polymer. In addition to the above-mentioned polymer, the resist composition may optionally contain components such as organometallic compounds and organometallic complexes. Each component will be explained below. The resist composition of one embodiment of the present invention may contain other components as long as the effects of the present invention are not impaired. Examples of components that can be added include at least one selected from known additives, such as fluorine-containing water-repellent polymers, quenchers such as trioctylamine, surfactants, fillers, pigments, antistatic agents, flame retardants, light stabilizers, antioxidants, ion scavengers, and solvents.

[0120] <3> Method for Preparing Resist Composition The method for preparing the resist composition of one embodiment of the present invention is not particularly limited, and the resist composition can be prepared by a known method such as mixing, dissolving, or kneading the polymer and other optional components. The polymer can be synthesized by appropriately polymerizing the monomers that constitute the unit A and unit B, and, if necessary, monomers that constitute other units, using a conventional method. However, the method for producing the polymer of the present invention is not limited to this.

[0121] <4> Manufacturing Method of Member One aspect of the present invention is a manufacturing method of a member, which includes a resist film forming step of forming a resist film on a substrate using the resist composition, a photolithography step of exposing the resist film in a pattern using particle beams or electromagnetic waves, and a pattern forming step of developing the exposed resist film with a developer to dissolve the exposed areas, thereby obtaining a photoresist pattern. Examples of the member include devices and masks.

[0122] Examples of particle beams or electromagnetic waves used for exposure in the photolithography process include electron beams and EUV, respectively. The amount of light irradiation varies depending on the types and blending ratios of each component in the photocurable composition, the film thickness of the coating film, etc., but is generally 1 J / cm. ２ or less than 1000 μC / cm ２ The resist composition preferably has the above M + When the polymer contains either the unit A represented by the formula (3) or (4), it is also preferable to further irradiate the polymer with a second active energy ray having lower energy than the particle beam or electromagnetic wave after irradiation with the particle beam or electromagnetic wave. Examples of the second active energy ray include ultraviolet light. Further irradiation with the second active energy ray improves sensitivity.

[0123] Another aspect of the present invention is a pattern formation method including: a resist film formation step of forming a resist film on a substrate using the resist composition; a photolithography step of exposing the resist film using particle beams or electromagnetic beams; and a pattern formation step of developing the exposed resist film using a developer to dissolve the exposed portions, thereby obtaining a photoresist pattern.

[0124] It is preferable to use an organic solvent for development in the pattern formation process. As described above, in one embodiment of the polymer of the present invention, upon exposure to particle beams or electromagnetic rays, the unit A decomposes, causing a significant polarity change from ionic to nonionic. At the same time, the decomposition of the unit A protonates the f-valent anion, generating an acid. This causes the polymer formed via the anion to decompose, eliminating the crosslinked structure between polymer molecules, thereby changing the solubility of the polymer. Therefore, a resist composition containing the polymer can significantly change its solubility due to the polarity change caused by the decomposition of the unit A as well as the decomposition of the polymer. Therefore, even without using acid diffusion, a positive pattern can be obtained by dissolving the exposed area with high sensitivity and maintaining high development contrast using an organic solvent as a developer.

[0125] The organic solvent used as a developer for obtaining positive patterning can be appropriately selected from known organic solvents used as organic solvent developers. Specific examples include ketone solvents, ester solvents, nitrile solvents, alcohol solvents, and ether solvents. Examples of ketone solvents include acetone, 2-heptanone, 2-hexanone, cyclohexanone, acetophenone, methyl ethyl ketone, diisobutyl ketone, and diacetone alcohol. Examples of ester solvents include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, hexyl acetate, propylene glycol monomethyl ether acetate (PGMEA), and ethylene glycol monoethyl ether acetate. Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0126] Examples of alcohol-based solvents include alcohols such as ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, n-hexyl alcohol, and n-heptyl alcohol; glycol-based solvents such as ethylene glycol, propylene glycol, and diethylene glycol; and glycol ether-based solvents such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and methoxymethylbutanol. Examples of ether-based solvents include the above glycol ether-based solvents as well as di-n-propyl ether, di-n-butyl ether, dioxane, and tetrahydrofuran.

[0127] Some organic solvents contain multiple types of functional groups that characterize the above-mentioned solvents in their structure, and in such cases, the term "organic solvent" refers to any solvent containing the functional groups contained in the organic solvent. For example, diethylene glycol monomethyl ether is considered to be both an alcohol-based solvent and an ether-based solvent in the above classification.

[0128] The developer used in the present invention is preferably prepared appropriately depending on the composition of the resist composition containing the polymer. The developer may be a combination of two or more of the above organic solvents. The developer used in the member manufacturing method of one embodiment of the present invention can be an organic solvent appropriately selected from those suitable for the resist composition of one embodiment of the present invention. The developer is not particularly limited, but is preferably selected, for example, as follows: (1) A resist composition sample is prepared by dissolving the polymer in a solvent containing ethyl lactate and γ-butyrolactone in a 9:1 ratio, and a film is prepared by applying the composition to a predetermined film thickness. (2) Various organic solvents are prepared as the developer. (3) Each film obtained in (1) above is impregnated with various organic solvents. The film is then dried and the film thickness is measured. (4) An organic solvent that results in a desired remaining film ratio based on the film thickness measurement obtained in (3) above is selected as the developer for the resist composition sample.

[0129] In the present invention, butyl acetate, amyl acetate, hexyl acetate, 2-heptanone, propylene glycol monomethyl ether acetate (PGMEA), and the like are preferred.

[0130] Some aspects of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0131] The following compounds A1 to A5, B1 to B2, B5, and C1 to C2 were synthesized with reference to the examples in WO 2022 / 039212. The following compounds B3 and B4 were synthesized with reference to the examples in JP 2023-122060 A.

[0132]

[0133] <Synthesis of Compound A6 Constituting Unit A> (Synthesis Example 1) Synthesis of 4-hydroxyphenyl-2-[dipropionyl-(4-methoxyphenyl)methyl]dibenzothiophenium-methyl sulfate 2.5 g of 4-hydroxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium-methyl sulfate was added to 20 g of 1-propanol, and 5.0 g of trimethyl orthoformate and 20 mg of concentrated sulfuric acid were added thereto and stirred at 60°C for 3 hours. After stirring, the reaction solution was added to a mixed solution of 60 g of methylene chloride and 10 g of a 3% by mass aqueous solution of sodium bicarbonate and stirred for 10 minutes to recover the organic layer. The resulting organic layer was washed three times with water, and the methylene chloride was then distilled off to obtain 2.0 g of 4-hydroxyphenyl-2-[dipropionyl-(4-methoxyphenyl)methyl]dibenzothiophenium-methyl sulfate. 4-Hydroxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate was synthesized with reference to WO2022 / 039212.

[0134]

[0135] Synthesis Example 2: Synthesis of 4-metachloroxyphenyl-2-[dipropioxy-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate (Compound A6) 4.0 g of 4-hydroxyphenyl-2-[dipropioxy-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate obtained in Synthesis Example 1 above and 1.9 g of methacrylic acid chloride were dissolved in 25 g of methylene chloride and the temperature was brought to 25°C. A solution of 1.4 g of triethylamine dissolved in 7 g of methylene chloride was added dropwise to the solution and stirred at 25°C for 2 hours. After stirring, 20 g of pure water was added and stirred for an additional 10 minutes, followed by separation of the layers. The organic layer was washed twice with 20 g of pure water, and the collected organic layer was concentrated and added dropwise to 60 g of diisopropyl ether to precipitate a solid. The precipitated solid is filtered off and dried to obtain 3.8 g of 4-methacryloxyphenyl-2-[dipropionoxy-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate (Compound A6).

[0136]

[0137] Synthesis Example 3: Synthesis of 4-hydroxyphenyl-2-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate 2.0 g of 4-hydroxyphenyl-2-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate was obtained by the same procedure as in Synthesis Example 1 above, except for using 4-hydroxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate instead of 4-hydroxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate and replacing methanol with 1,4-butanediol. 4-hydroxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate was synthesized with reference to WO 2022 / 039212.

[0138]

[0139] <Synthesis of Compound A7 Constituting Unit A> (Synthesis Example 4) Synthesis of 4-methacroxyphenyl-2-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]dibenzothiophenium methylsulfate (Compound A7) 3.8 g of 4-methacroxyphenyl-2-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]dibenzothiophenium methylsulfate (Compound A7) was obtained by the same procedure as in Synthesis Example 2 above, except that 4-hydroxyphenyl-2-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]dibenzothiophenium methylsulfate obtained in Synthesis Example 3 above was used instead of 9-(4-hydroxyphenyl)dibenzothiophenium methylsulfate.

[0140]

[0141] <Synthesis of Compound A8 Constituting Unit A> (Synthesis Example 5) Synthesis of {4-[dimethoxy-(4-methacryloxyphenyl)methyl]phenyl}diphenylsulfonium methylsulfate (Compound A8) 3.0 g of {4-[dimethoxy-(4-methacryloxyphenyl)methyl]phenyl}diphenylsulfonium iodide instead of 9-(4-hydroxyphenyl)dibenzothiophenium iodide and 2.3 g of dimethyl sulfate were dissolved in 15 g of methanol, the temperature was raised to 25°C, and the mixture was stirred at room temperature for 4 hours. Thereafter, 45 g of diisopropyl ether was added to precipitate a solid. The precipitated solid was filtered and dried to obtain 2.3 g of {4-[dimethoxy-(4-methacryloxyphenyl)methyl]phenyl}diphenylsulfonium methylsulfate (Compound A8). Incidentally, {4-[dimethoxy-(4-methacryloxyphenyl)methyl]phenyl}diphenylsulfonium iodide was synthesized with reference to the examples in JP-A No. 2023-122060.

[0142]

[0143] <Synthesis of Compound A9 Constituting Unit A> (Synthesis Example 6) Synthesis of (4-{dimethoxy-[4-(3-methacryloxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium methylsulfate (Compound A9) 2.3 g of (4-{dimethoxy-[4-(3-methacryloxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium methylsulfate (Compound A9) was obtained by the same procedure as in Synthesis Example 5 above, except for using (4-{dimethoxy-[4-(3-methacryloxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium methylsulfate (Compound A9). Note that (4-{dimethoxy-[4-(3-methacryloxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium iodide was synthesized with reference to JP 2023-122060 A.

[0144]

[0145] <Synthesis of Compound C3 Constituting Unit C> (Synthesis Example 7) Synthesis of 4-hydroxy-4'-methoxy-α-methylbenzhydrol 6.0 g of 4-hydroxy-4'-methoxybenzophenone was dissolved in 32 g of THF, and 39 ml of a 2.0 M methylmagnesium bromide / THF solution was added thereto and stirred at room temperature for 3 hours. Thereafter, the mixture was cooled to below 10°C, and 6 g of pure water was added thereto and stirred for an additional 10 minutes. After stirring, 30 g of ethyl acetate was added and the mixture was separated. This mixture was washed three times with 10 g of water, and the collected organic layer was concentrated to obtain 5.1 g of 4-hydroxy-4'-methoxy-α-methylbenzhydrol.

[0146]

[0147] Synthesis Example 8 Synthesis of 4-methacryloxy-4'-methoxy-α-methylbenzhydrol (Compound C3) 4.0 g of 4-hydroxy-4'-methoxy-α-methylbenzhydrol obtained in Synthesis Example 7 above and 4.2 g of methacrylic anhydride were dissolved in 40 g of methylene chloride and the temperature was adjusted to 25°C. A solution of 2.8 g of triethylamine in 7 g of methylene chloride was added dropwise to the solution and stirred at 25°C for 2 hours. After stirring, 20 g of pure water was added and stirred for an additional 10 minutes, followed by separation of the layers. The organic layer was washed twice with 20 g of pure water and then collected and concentrated. The solvent was distilled off from the resulting organic layer, and the resulting organic layer was purified by column chromatography (ethyl acetate / hexane = 15 / 85 (volume ratio)) to obtain 3.1 g of 4-methacryloxy-4'-methoxy-α-methylbenzhydrol (Compound C3).

[0148]

[0149] <Synthesis of Polymers> (Synthesis Example 9) Synthesis of Polymer 1 3.0 g of the compound A1 constituting unit A, 2.0 g of the compound B1 constituting unit B, 0.71 g of dimethyl-2,2'-azobis(2-methylpropionate) as a polymerization initiator, and 0.15 g of α-thioglycerol were dissolved in a mixed solution of 9 g of cyclohexanone and 13 g of γ-butyrolactone and deoxygenated. This solution was added dropwise over 4 hours to a mixed solution of 4 g of γ-butyrolactone and 4 g of cyclohexanone that had been preheated to 80°C. After the dropwise addition, the mixture was stirred for 2 hours and then cooled. After cooling, the mixture was added dropwise to 90 g of ethyl acetate to reprecipitate. After filtering, the mixture was stirred in 40 g of a 20% by weight aqueous methanol solution for 10 minutes, filtered, and vacuum dried to obtain 4.5 g of the target polymer 1. The unit ratio of polymer 1 shown below is an example, and the polymers of some embodiments of the present invention are not limited thereto. In other polymers, the unit ratios disclosed in the examples are merely examples, and the polymers of some embodiments of the present invention are not limited thereto.

[0150]

[0151] Synthesis Example 10 Synthesis of Polymer 2 4.5 g of Polymer 2 was obtained in the same manner as in Synthesis Example 9, except that Compound A2 was used instead of Compound A1 constituting Unit A.

[0152]

[0153] Synthesis Example 11 Synthesis of Polymer 3 3.1 g of Polymer 3 was obtained in the same manner as in Synthesis Example 9, except that Compound B3 was used instead of Compound B1 constituting Unit B and Compound C1 constituting Unit C was used.

[0154]

[0155] Synthesis Example 12 Synthesis of Polymer 4 5.3 g of Polymer 4 was obtained in the same manner as in Synthesis Example 9, except that Compound A2 was used instead of Compound A1 constituting Unit A and Compound C3 constituting Unit C was used.

[0156]

[0157] Synthesis Example 13 Synthesis of Polymer 5 3.0 g of compound A5 constituting unit A, 2.1 g of compound B1 constituting unit B, 1.6 g of compound C1 constituting unit C, 0.71 g of dimethyl-2,2'-azobis(2-methylpropionate) as a polymerization initiator, and 0.15 g of α-thioglycerol were dissolved in a mixed solution of 9 g of cyclohexanone and 13 g of γ-butyrolactone and deoxygenated. This solution was added dropwise over 4 hours to a mixed solution of 4 g of γ-butyrolactone and 4 g of cyclohexanone that had been preheated to 80°C. After the dropwise addition, the mixture was stirred for 2 hours and then cooled. After cooling, the mixture was added dropwise to 90 g of ethyl acetate to reprecipitate. The mixture was filtered and then stirred in 40 g of 20% by weight aqueous methanol solution for 10 minutes, filtered, and vacuum dried to obtain 5.3 g of the target polymer 5.

[0158]

[0159] Synthesis Example 14 Synthesis of Polymer 6 3.0 g of compound A8 constituting unit A, 2.1 g of compound B3 constituting unit B, 1.6 g of compound C1 constituting unit C, 0.71 g of dimethyl-2,2'-azobis(2-methylpropionate) as a polymerization initiator, and 0.15 g of α-thioglycerol were dissolved in a mixed solution of 9 g of cyclohexanone and 13 g of γ-butyrolactone and deoxygenated. This solution was added dropwise over 4 hours to a mixed solution of 4 g of γ-butyrolactone and 4 g of cyclohexanone that had been preheated to 80°C. After the dropwise addition, the mixture was stirred for 2 hours and then cooled. After cooling, the mixture was added dropwise to 90 g of hexane to reprecipitate. The mixture was filtered and then stirred in 40 g of 20% by weight aqueous methanol solution for 10 minutes, filtered, and vacuum dried to obtain 5.3 g of the target polymer 6.

[0160]

[0161] Synthesis Example 15: Synthesis of Polymer 1a 2.0 g of Polymer 1 obtained in Synthesis Example 9 above and 0.1 g of disodium tetrafluorosuccinate were added to 25 g of methylene chloride and 20 g of pure water, and the mixture was stirred at 25°C for 1 hour. The resulting mixture was then separated, and the recovered organic layer was added dropwise to ethyl acetate to reprecipitate. The resulting mixture was filtered and vacuum dried to obtain 1.8 g of the target polymer 1a.

[0162]

[0163] Synthesis Example 16: Synthesis of Polymer 1b 2.0 g of Polymer 1 obtained in Synthesis Example 9 above and 0.2 g of disodium tetrafluorosuccinate were added to 25 g of methylene chloride and 20 g of pure water, and the mixture was stirred at 25°C for 1 hour. The resulting mixture was then separated, and the recovered organic layer was added dropwise to ethyl acetate to reprecipitate. The resulting mixture was filtered and vacuum dried to obtain 1.2 g of the target polymer 1b.

[0164]

[0165] Synthesis Example 17: Synthesis of Polymer 1c 2.0 g of Polymer 1 obtained in Synthesis Example 9 above and 0.066 g of trisodium citrate were added to 25 g of methylene chloride and 20 g of pure water, and the mixture was stirred at 25°C for 1 hour. The resulting mixture was then separated, and the recovered organic layer was added dropwise to ethyl acetate to reprecipitate. The resulting mixture was filtered and vacuum dried to obtain 1.8 g of the target polymer 1c.

[0166]

[0167] Synthesis Example 18: Synthesis of Polymer 1d 2.0 g of Polymer 1 obtained in Synthesis Example 9 above and 0.1 g of disodium 1,2-ethanedisulfonate were added to 25 g of methylene chloride and 20 g of pure water, and the mixture was stirred at 25°C for 1 hour. After that, the mixture was separated, and the recovered organic layer was added dropwise to ethyl acetate to cause reprecipitation. This was filtered and dried in vacuo to obtain 1.8 g of the target polymer 1d.

[0168]

[0169] Synthesis Example 19: Synthesis of Polymer 1e 2.0 g of Polymer 1 obtained in Synthesis Example 9 above and 0.1 g of disodium L-cysteine ​​acid were added to 25 g of methylene chloride and 20 g of pure water, and the mixture was stirred at 25°C for 1 hour. After that, the mixture was separated, and the recovered organic layer was added dropwise to ethyl acetate to reprecipitate. The resulting mixture was filtered and dried under vacuum to obtain 1.8 g of the target polymer 1e.

[0170]

[0171] Synthesis Example 20: Synthesis of Polymer 3a 2.0 g of Polymer 3 obtained in Synthesis Example 11 above and 0.067 g of disodium tetrafluorosuccinate were added to 25 g of methylene chloride and 20 g of pure water, and the mixture was stirred at 25°C for 1 hour. The mixture was then separated, and the recovered organic layer was added dropwise to ethyl acetate to reprecipitate. The resulting mixture was filtered and vacuum dried to obtain 1.8 g of the target polymer 3a.

[0172]

[0173] Synthesis Example 21: Synthesis of Polymer 4a 2.0 g of Polymer 4 obtained in Synthesis Example 12 above and 0.07 g of disodium tetrafluorosuccinate were added to 25 g of methylene chloride and 20 g of pure water, and the mixture was stirred at 25°C for 1 hour. The mixture was then separated, and the recovered organic layer was added dropwise to ethyl acetate to reprecipitate. The resulting mixture was filtered and vacuum dried to obtain 1.8 g of the target polymer 4a.

[0174]

[0175] Synthesis Example 22: Synthesis of Polymer 5a 2.0 g of Polymer 5 obtained in Synthesis Example 13 above and 0.05 g of disodium tetrafluorosuccinate were added to 25 g of methylene chloride and 20 g of pure water, and the mixture was stirred at 25°C for 1 hour. The resulting mixture was then separated, and the recovered organic layer was added dropwise to ethyl acetate to reprecipitate. The resulting mixture was filtered and vacuum dried to obtain 1.8 g of the target polymer 5a.

[0176]

[0177] Synthesis Example 23: Synthesis of Polymer 6a 2.0 g of Polymer 6 obtained in Synthesis Example 14 above and 0.05 g of disodium tetrafluorosuccinate were added to 25 g of methylene chloride and 20 g of pure water, and the mixture was stirred at 25°C for 1 hour. The resulting mixture was then separated, and the recovered organic layer was added dropwise to ethyl acetate to reprecipitate. The resulting mixture was filtered and vacuum dried to obtain 1.8 g of the target polymer 6a.

[0178]

[0179] The composition ratio of the polymers was measured by a general quantitative method using a nuclear magnetic resonance (NMR) spectrometer, C-NMR. The anion ratio of unit D to unit A in the polymers 1a to 6a was calculated by a general quantitative method using anion chromatography.

[0180] <Preparation of Resist Composition> Of the above polymers, 50 mg of polymers 1a, 1b, 1e, 3a, 4a, and 5a, or polymers 1, 3, and 4 (as comparative samples) were dissolved in a solvent containing a 9:1 mixture of ethyl lactate and γ-butyrolactone to prepare resist composition samples 1 to 5 of Examples 1 to 5 and resist composition samples 6 to 8 of Comparative Examples 1 to 3.

[0181] <Preparation of Developer> Developers were prepared as follows. (1) Using resist composition samples 1 to 6, each of the above polymers was dissolved in a solvent containing ethyl lactate and γ-butyrolactone in a 9:1 ratio, and films were prepared by spin coating to a film thickness of 200 nm. (2) As developers, butyl acetate, amyl acetate, hexyl acetate, 2-heptanone, and propylene glycol monomethyl ether acetate (PGMEA) were prepared. (3) Each film obtained in (1) above was immersed in the developer for 30 seconds. The film was then placed on a spin coater and dried by spinning at 2000 rpm for 30 seconds, and the film thickness was measured. (4) The organic solvent that gave a residual film rate of 70% or more based on the film thickness measurement obtained in (3) above was used as the developer for each resist composition sample.

[0182] <EUV Exposure Evaluation> Resist composition sample 1 was dropped onto a 6-inch silicon wafer and spin-coated, followed by baking on a hot plate at 110°C for 1 minute to form a film with a thickness of 200 nm. The obtained film was irradiated with EUV using an EUV exposure device (EQ-10m, manufactured by Energetiq Technology), and then developed by immersing for 30 seconds in a developer previously prepared for each sample. After development, the film was placed on a spin coater and dried by rotating at 2000 rpm for 20 seconds to form a 1 × 1 cm ２ The film thickness of the exposed portion of the obtained pattern was measured using a contact film thickness meter (Surfcorder ET-200, manufactured by Kosaka Laboratory Co., Ltd.), and the sensitivity (E ０ ) was obtained. ０is defined as the exposure dose when the film thickness of the exposed area is 5% or less of the initial film thickness, and the sensitivity of sample 1 is compared. Furthermore, the film thickness of the unexposed area is measured and the residual film ratio after development is calculated. For resist composition samples 2 to 10, the sensitivity evaluation and residual film ratio are calculated in the same manner as for resist composition sample 1. The sensitivity of each of resist composition samples 2 to 10 is compared using the sensitivity of resist composition sample 1 as the reference value, and the relative sensitivity (E ０ The relative sensitivity (E) and the remaining film ratio of the unexposed area were calculated and the results are shown in Table 1. ０ ) indicates that the smaller the value, the higher the sensitivity.

[0183]

[0184] The combinations of Examples 1 to 3 and Comparative Example 1, Example 4 and Comparative Example 2, Example 5 and Comparative Example 3, and Example 6 and Comparative Example 4 have the same polymer composition except for the valence of the onium salt structure anion. Comparison of Examples 1 to 6 and Comparative Examples 1 to 4 reveals that, even when the polymer compositions are the same except for the valence of the anion of the unit having an onium salt structure, the polymer of one embodiment of the present invention has a significantly reduced solubility in organic solvents of the unexposed areas due to the inclusion of unit A, i.e., a polyvalent anion. In the polymer of one embodiment of the present invention, the cation moiety of unit A decomposes to an acid upon EUV exposure, and the valence of the anion decreases, and the polarity conversion due to decomposition of the cation causes the exposed areas to dissolve in organic solvents, making it possible to produce a greater development contrast than Comparative Examples 1 to 4, which do not have anions with a valence of two or more.

[0185] In a polymer according to one embodiment of the present invention, the unit A has a polyvalent anion having a valence of two or more, and thus the polymer is connected by an ionic bond. Therefore, the polymer has higher ionicity than a comparative polymer containing a unit having an onium salt structure having a monovalent anion, and the polymer size is large, resulting in low solubility in organic solvents. On the other hand, when the polymer according to one embodiment of the present invention is exposed to EUV or EB, the unit A is decomposed into an acid, which reduces the ionicity, and the polymer size is further reduced, making it more soluble in organic solvents.

[0186] A comparison between Examples 1 and 2 reveals that increasing the composition of unit A increases the proportion of ionic groups in the resist composition, making polymer 1b of Example 2 less soluble in organic solvents than polymer 1a of Example 1, thereby improving the film retention rate in unexposed areas. However, polymer 1b of Example 2 requires decomposition of more unit A than polymer 1b of Example 1, which tends to reduce the relative sensitivity. From these results, it can be expected that trivalent or higher polyvalent anions such as polymer 1c and polymer 3e can increase the proportion of ionic groups in the polymer even with a small amount introduced, effectively reducing the solubility of the polymer in organic solvents in unexposed areas.

[0187] <EUV-UV Exposure Evaluation> Resist composition sample 4 was dropped onto a 6-inch silicon wafer and spin-coated, and then baked on a hot plate at 110°C for 1 minute to form a film with a thickness of 200 nm. The obtained film was irradiated with EUV using an EUV exposure device (EQ-10m, manufactured by Energetiq Technology), and then irradiated with 1000 mJ / cm using a 395 nm UV-LED. ２ The entire surface was irradiated with an exposure dose of 1000 rpm. Then, the sample was immersed in a developer previously set for each sample for 60 seconds for development. After development, the sample was placed on a spin coater and rotated at 2000 rpm for 30 seconds to dry, resulting in a 1 × 1 cm ２ The film thickness of the exposed portion of the obtained pattern was measured using a contact film thickness meter (Surfcorder ET-200, manufactured by Kosaka Laboratory Co., Ltd.), and the sensitivity (E ０ ) was obtained. ０ is defined as the exposure dose when the film thickness of the exposed area is 5% or less of the initial film thickness, and the sensitivity of resist composition sample 4 is compared. Furthermore, the film thickness of the unexposed area is measured and the remaining film ratio after development is calculated. For resist composition sample 6, the sensitivity evaluation and remaining film ratio are calculated in the same manner as above. The sensitivity of resist composition sample 6 is compared using the sensitivity of resist composition sample 4 as the reference value, and the calculation results of the relative sensitivity and remaining film ratio of the unexposed area are shown in Table 2. Relative sensitivity (E ０ ) indicates that the smaller the value, the higher the sensitivity.

[0188]

[0189] In Table 1 above, a comparison between Example 4 and Example 6 shows that polymer 3a and polymer 5a have similar sensitivity to EUV exposure. However, in Table 2, a comparison between Example 7 and Example 8 shows that polymer 5a has better sensitivity. This is because polymer 5a, which has compound A5 as unit A, has its acetal group deprotected by the acid generated after EUV irradiation, shifting the absorption peak wavelength of the polymer to a longer wavelength. Irradiating the longer-wavelength polymer with 395 nm UV further generates acid, resulting in higher sensitivity than polymer 3a, which has compound A1 as unit A.

[0190] Since the polymer of one embodiment of the present invention is a polymer containing an organometallic compound-containing unit B, after irradiation with EUV or EB, the exposed area can be dissolved by developing with an organic solvent as a developer. Furthermore, by containing either of the above formulas (3) and (4) as unit A, sensitivity is improved by UV irradiation, making it possible to form a pattern with a reduced EUV exposure dose. The polymers of several embodiments of the present invention and resist compositions containing such polymers are effective because they can reduce the amount of energy required for pattern formation. Furthermore, since the polymer of one embodiment of the present invention contains unit B, it is expected to have excellent etching resistance. Even if the polymer is not one of the polymers evaluated in the examples, polymers containing the above unit A and unit B will have excellent effects on sensitivity, development contrast characteristics, and etching characteristics, similar to the polymers evaluated in the examples.

[0191] Some aspects of the present invention can provide a polymer that has high absorption efficiency for particle rays or electromagnetic waves such as EUV, and is excellent in sensitivity, development contrast characteristics, and etching resistance, and a resist composition containing the polymer.

Claims

1. Unit A, which has an onium salt structure and generates acid upon irradiation with particle beams or electromagnetic waves, A unit B containing an organometallic compound having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi, and Te, The unit A is a polymer represented by the following formula (1). 【Chemistry 1】 (In the above general formula (1), R １ R is selected from the group consisting of a hydrogen atom; a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched, or cyclic alkenyl group having 2 to 6 carbon atoms. １ At least one hydrogen atom in the alkyl and alkenyl groups within may be substituted with a substituent. L is selected from the group consisting of a direct bond, a carbonyloxy group, a carbonylamino group, a phenylenediyl group, a naphthalenediyl group, a phenylenediyloxy group, a naphthalenediyloxy group, a phenylenediylcarbonyloxy group, a naphthalenediylcarbonyloxy group, a phenylenediyloxycarbonyl group, and a naphthalenediyloxycarbonyl group. Sp is one of the following: a direct bond; a linear, branched, or cyclic alkylene group having 1 to 6 carbon atoms, which may have substituents; and a linear, branched, or cyclic alkenylene group having 2 to 6 carbon atoms, which may have substituents, and at least one methylene group in Sp may be substituted with a divalent heteroatom-containing group. M ＋ is a sulfonium cation group or an iodonium cation group, X － It is a monovalent anionic group, f is an integer between 2 and 4, and f X are connected to R. － , the X － f M corresponding to + f R １ The f Ls and f Sps may be the same or different from each other. R is a C1-C6 f-valent hydrocarbon group which may have substituents, and at least one hydrogen atom in R may be substituted with a substituent, and at least one methylene group in R may be substituted with a divalent heteroatom-containing group.

2. X － is any one selected from the group consisting of: alkyl sulfate anions; aryl sulfate anions; alkyl sulfonate anions; aryl sulfonate anions; alkyl carboxylate anions; aryl carboxylate anions; dialkyl sulfonylimide anions; trialkyl sulfonate methide anions; and tetrakisphenyl borate anions; X － At least one hydrogen atom of the alkyl group and aryl group in X may be substituted with a substituent. － The polymer according to claim 1, wherein at least one methylene group in the alkyl group is substituted with a divalent heteroatom-containing group.

3. The polymer according to claim 1, wherein the unit A is represented by the following formula (2). 【Chemistry 2】 (In the above general formula (2), R １ L, Sp, X － and f are R in the general formula (1) above, respectively. １ L, Sp, X － And selected from the same options as f, R ６ａ R is selected from the group consisting of: a linear, branched, or cyclic alkylene group having 1 to 6 carbon atoms which may have substituents; a linear, branched, or cyclic alkenylene group having 2 to 6 carbon atoms which may have substituents; an arylene group having 6 to 14 carbon atoms which may have substituents; a heteroarylene group having 4 to 12 carbon atoms which may have substituents; and a direct bond; and the R ６ａ At least one methylene group in the compound may be substituted with a divalent heteroatom-containing group. R ６ｂ Each of these is independently selected from the group consisting of optionally substituted linear, branched, or cyclic C1-C6 alkyl groups; optionally substituted linear, branched, or cyclic C2-C6 alkenyl groups; optionally substituted C6-C14 aryl groups; and optionally substituted C4-C12 heteroaryl groups, and the R ６ｂ At least one methylene group in the compound may be substituted with a divalent heteroatom-containing group. R ６ａ and two R ６ｂ Two of these may form a ring structure with the sulfur atom to which they are bonded, either directly by a single bond or via a selection from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group, and a methylene group. f X's connected to R － f R ６ａ f R ６ｂ f R 1 (The f Ls and f Sps may be the same or different from each other.)

4. Said M ＋ The polymer according to claim 1, wherein is represented by either the following general formula (3) or the following formula (4). 【Transformation 3】 (In formula (3) above, R １１ and R １２ Each of these is independently selected from the group consisting of: optionally substituted linear, branched, or cyclic alkyl groups having 1 to 12 carbon atoms; optionally substituted linear, branched, or cyclic alkenyl groups having 2 to 12 carbon atoms; optionally substituted aryl groups having 6 to 14 carbon atoms; and optionally substituted heteroaryl groups having 4 to 12 carbon atoms. The aforementioned R 1１ , R １２ And any two or more of the aryl groups to which the sulfonium group is bonded may form a ring structure with the sulfur atom to which they are bonded, either directly by a single bond, or via any of the group selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group, and a methylene group. The aforementioned R 1１ and R １２ At least one methylene group in the compound may be substituted with a divalent heteroatom-containing group. R １３ and R １４ Each of these is independently selected from the group consisting of alkyl groups, hydroxyl groups, mercapto groups, alkylene oxy groups, alkylcarbonyl groups, arylcarbonyl groups, alkylene oxycarbonyl groups, aryloxycarbonyl groups, arylsulfanylcarbonyl groups, arylsulfanyl groups, alkylsulfanyl groups, aryl groups, heteroaryl groups, aryloxy groups, alkylsulfinyl groups, arylsulfinyl groups, alkylsulfonyl groups, arylsulfonyl groups, (meth)acryloyloxy groups, hydroxy(poly)alkylene oxy groups, amino groups, cyano groups, nitro groups, and halogen atoms, and if carbon is present, the number of carbon atoms is 1 to 12, and these may have substituents. One R １４ However, the R is formed via any of the following: direct bonding, methylene group, oxygen atom, sulfur atom, and divalent nitrogen atom-containing group. １４ They may form a ring structure with the aryl group to which they are bonded. R １５ and R １６ Each of these is independently selected from the group consisting of: a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, which may have substituents; an aryl group having 6 to 14 carbon atoms, which may have substituents; and a heteroaryl group having 4 to 12 carbon atoms, which may have substituents. The aforementioned R １５ and R １６ These elements may be bonded to each other directly by single bonds, or via any of the elements selected from the group consisting of oxygen atoms, sulfur atoms, and alkylene groups, to form a ring structure. The aforementioned R １５ and R １６ At least one methylene group in the compound may be substituted with a divalent heteroatom-containing group. L ２ This is one of the groups selected from the following: directly bonded; linear, branched, or cyclic alkylene groups having 1 to 12 carbon atoms; alkenylene groups having 2 to 12 carbon atoms; arylene groups having 6 to 14 carbon atoms; heteroarylene groups having 4 to 12 carbon atoms; and groups in which these groups are bonded via oxygen, sulfur, or divalent nitrogen atom-containing groups. L ３ This is selected from the group consisting of a direct bond, a methylene group, a sulfur atom, a divalent nitrogen atom-containing group, and an oxygen atom. Y is an oxygen atom or a sulfur atom, h is an integer between 1 and 2, i is an integer between 1 and 3. j is an integer between 0 and 3 when h is 1, and between 0 and 5 when h is 2. k is an integer between 0 and 4 when i is 1, between 0 and 6 when i is 2, and between 0 and 8 when i is 3. R １１ , R １２ and R １４ Any one of the hydrogens and R １４ The hydrogen atom on the aryl ring to which is bonded is replaced by the bond with Sp in formula (1) above. In the above formula (4), R １１ ~R １６ , L ２ And Y independently each have R in formula (3) above. １１ ~R １６ , L ２ And Y are selected from the same options, h is an integer between 1 and 2, i is an integer between 1 and 3. j is an integer between 0 and 4 when h is 1, and between 0 and 6 when h is 2. k is an integer between 0 and 5 when i is 1, between 0 and 7 when i is 2, and between 0 and 9 when i is 3. L ４ and L ５ Each of these is independently selected from the group consisting of a direct bond, a two-carbon alkenylene group, a two-carbon alkynylene group, and a carbonyl group.

5. The polymer according to claim 1, further comprising a unit D, wherein the unit D is represented by the following formula (1). 【Chemistry 4】 (In the above general formula (6), R １ L, Sp, M ＋ This is R as described in the general formula (1) above. １ L, Sp, M ＋ Selected from the same options, Z － (It is a monovalent anion.)

6. The polymer according to claim 1, wherein the molar ratio of unit D to unit A is 0 to 20.

7. The polymer according to claim 1, further comprising unit C, wherein unit C is a unit in which a compound represented by the following general formula (I) or (II) is bonded to an Sp group of the following formula (5) at any position of the compound. 【Transformation 5】 (In the above general formula (I), R ２ and R ３ Each of these is independently selected from the group consisting of a hydrogen atom; an electron-donating group; and an electron-withdrawing group. E is selected from the group consisting of direct bonds; oxygen atoms; sulfur atoms; and methylene groups. R ４ is selected from the group consisting of optionally substituted alkyl groups and optionally substituted alkenyl groups, n １ is an integer of 0 or 1, n ４ and n ５ Each of these is an integer between 1 and 2, and n ４ +n ５ The range is 2 to 4, n ４ When n is 1 ２ n is an integer between 0 and 4, and ４ When n is 2 ２ is an integer from 0 to 6, n ５ When n is 1 ３ n is an integer between 0 and 4, and ５ When n is 2 ３ is an integer from 0 to 6, n ２ If it is 2 or more, R ２ When is an electron-donating group or an electron-withdrawing group, two R ２ However, they may form a ring structure with each other either directly by single bonds or via any of the group selected from oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups. n ３ If it is 2 or more, R ３ When is an electron-donating group or an electron-withdrawing group, two R ３ However, they may form a ring structure with each other either directly by single bonds or via any of the group selected from oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups. In the above general formula (II), R ４ is selected from the group consisting of optionally substituted alkyl groups and optionally substituted alkenyl groups, R ５ is selected from the group consisting of a hydrogen atom; an optionally substituted alkyl group; and an optionally substituted alkenyl group, and the R ５ At least one methylene group in the R may be substituted with a divalent heteroatom-containing group, ５ is the R ５ A hydroxymethylene group having this may form a ring structure together with a benzene ring to which it is bonded. R ６ Each of these is independently selected from the group consisting of a hydrogen atom; an electron-donating group; and an electron-withdrawing group. R ６ at least one of which is said electron-donating group, n ６ is an integer from 0 to 7, n ７ is 1 or 2, n ７ When n is 1 ６ n is an integer between 0 and 5. ７ When n is 2 ６ is an integer from 0 to 7, n ６ is 2 or more, and R ４ is an electron-donating group or an electron-withdrawing group, the two R ４ groups may form a ring structure with each other either directly via a single bond, or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group and a methylene group.) 【Transformation 6】 (In the above formula (5), R １ , L and Sp are R in the general formula (1) above, respectively. １ , selected from the same options as L and Sp, * indicates the binding site with the compound represented by the general formula (I) or (II) above.

8. A resist composition containing the polymer according to any one of claims 1 to 7.

9. A resist film formation step of forming a resist film on a substrate using the resist composition described in claim 8, A photolithography step of exposing the resist film using a particle beam or electromagnetic wave, A pattern formation step involves developing the exposed resist film with a developer to dissolve the exposed areas and obtain a photoresist pattern, A method for manufacturing a component that includes [a certain component].

10. The method for manufacturing a member according to claim 9, wherein the developing solution is an organic solvent.

11. The method for manufacturing a member according to claim 9, wherein, in the photolithography step, after exposure with the particle beam or electromagnetic wave, a second active energy ray having lower energy than the particle beam or electromagnetic wave is further irradiated.

12. The method for manufacturing a member according to claim 9, wherein the particle beam is an electron beam and the electromagnetic wave is an extreme ultraviolet light.

13. A resist film formation step of forming a resist film on a substrate using the resist composition described in claim 8, A photolithography step of exposing the resist film using a particle beam or electromagnetic wave, A pattern forming method comprising a pattern forming step of dissolving the exposed areas of an exposed resist film by developing it with a developer to obtain a photoresist pattern.

14. The pattern forming method according to claim 13, wherein the developing solution is an organic solvent.

15. The pattern forming method according to claim 13, wherein, in the photolithography step, a second active energy beam having lower energy than the particle beam or electromagnetic wave is further irradiated after exposure with the particle beam or electromagnetic wave.

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