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

Abstract

Provided are: a polymer used in a resist composition which has high absorption efficiency and which is superior in the characteristics of sensitivity, resolution, and pattern performance, and whereby the effects of decreased sensitivity and worsening of pattern roughness that occur due to a decrease in energy application density are mitigated in patterning formed by particles and irradiation with electromagnetic waves or a particle beam having high photon energy; a resist composition containing the polymer; and a method for manufacturing a member using the polymer and the resist composition.　The polymer includes: a unit A that has an onium salt structure and generates acid by irradiating a particle beam or an electromagnetic wave; and a unit B having a structure that bonds as a result of acid catalyst reaction. The unit A is indicated by formula (1). (In general formula (1), R1 is any one selected from the group consisting of a hydrogen atom, a linear, branched, or cyclic C1–6 alkyl group, and a linear, branched, or cyclic C1–6 alkenyl group. At least one hydrogen atom in an alkyl group or alkenyl group in R1 can be substituted with a substituent. L is any 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 a direct bond, a linear, branched, or cyclic C1–6 alkylene group that may have a substituent, or a linear, branched, or cyclic C1–6 alkenylene group that may have a substituent. At least one methylene group among the Sp can be substituted by a divalent heteroatom-containing group. M+ represents a sulfonium ion or an iodonium ion. X– represents a monovalent anion having an organic group including at least one selected from the group consisting of a hydroxyl group and a sulfonyl group.)

Description

[Technical Field]

[0001] Some aspects of the present invention relate to a polymer used in a resist composition. Also, some aspects of the present invention relate to a resist composition containing the polymer, a method for manufacturing a member using the resist composition, a method for forming a pattern, and a method for forming a reverse pattern. [Background technology]

[0002] In recent years, photolithography technology using photoresists has 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 a growing 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 (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 the need for resist compositions that exhibit high sensitivity to EUV, electron beams, etc. is expected to 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 fine-dimensional patterns. Chemically amplified resists are known as resist compositions that meet these requirements (Patent Document 1). However, with conventional chemically amplified resists, as the resolution line width 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] To achieve reduced LWR and higher resolution in resists, a method is known in which acid generators having bulky acid anions with large molecular weights or acid anions bonded to polymers are used to reduce acid diffusion due to heat (Patent Documents 2 and 3).

[0006] 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 resolution and pattern performance. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 9-90637 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-53622 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-276910 Summary of the Invention [Problem to be solved by the invention]

[0008] Some aspects of the present invention aim to provide a polymer for use in a resist composition that exhibits excellent resolution and pattern performance characteristics by significantly suppressing acid diffusion, not only by utilizing an acid generated from an acid generator upon irradiation with a particle beam or electromagnetic wave, particularly an electron beam or EUV, but also by directly utilizing a reaction that occurs upon irradiation with an electron beam or EUV, etc., simultaneously with an acid-catalyzed reaction. An object of some aspects of the present invention is to provide a resist composition containing the above polymer, a method for manufacturing a member using the resist composition, a method for forming a pattern, and a method for forming a reverse pattern. [Means for solving the problem]

[0009] As a result of intensive research conducted by the present inventors to solve the above-mentioned problems, they discovered that by using a polymer in a resist composition that includes a unit A having a specific onium salt structure in which the anion is a monovalent organic group having at least one selected from the group consisting of a hydroxyl group and a sulfanyl group, and a unit B having a specific structure, it is possible to achieve high sensitivity and suppress line-wise roughness (LWR), and have completed several aspects of the present invention. More specifically, the inventors have discovered that when a resist composition containing the polymer is irradiated with particle beams, electromagnetic waves, or the like, the following occurs: First, the unit A decomposes, causing a major polarity change from ionic to nonionic. At the same time, the decomposition of the unit A generates an acid, which then induces an intramolecular crosslinking reaction between the hydroxyl groups in the unit B and / or between the unit A and the unit B. When the anion of the onium salt structure in the unit A has an organic group containing a hydroxyl group or a sulfanyl group, a portion of the anion bonds with the hydroxyl group or sulfanyl group in the anion and the unit B via an acid-catalyzed reaction, becoming incorporated into the polymer and forming an acid in the polymer anion. Therefore, a resist composition containing the polymer can suppress acid diffusion, exhibit high sensitivity, and suppress line-wise roughness (LWR).

[0010] One embodiment of the present invention that solves the above-mentioned problems is a polymer comprising: a unit A that has a specific onium salt structure having, as an anion, a monovalent organic group having at least one selected from the group consisting of a hydroxyl group and a sulfanyl group, and that generates an acid when irradiated with a particle beam or electromagnetic wave; and a unit B that has a structure that bonds via an acid-catalyzed reaction. The above unit A is represented by the following formula (1).

[0011] [ka]

[0012] (In the above general formula (1), R 1is 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 1 to 6 carbon atoms; 1 at least one hydrogen atom in the alkyl group and alkenyl group may be substituted with a substituent; 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; 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 1 to 6 carbon atoms, wherein at least one methylene group in Sp is optionally substituted with a divalent heteroatom-containing group, M + is a sulfonium ion or an iodonium ion, X - is a monovalent anion having a monovalent organic group in the anion, the monovalent organic group having at least one group selected from the group consisting of a hydroxyl group and a sulfanyl group.

[0013] One embodiment of the present invention is a resist composition containing the above polymer. Another aspect of the present invention is a method for producing a member, the method comprising: 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 to particle beams or electromagnetic waves; and a pattern formation step of developing the exposed resist film to obtain a photoresist pattern.

[0014] 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 to particle beams or electromagnetic waves; and a pattern formation step of developing the exposed resist film to obtain a photoresist pattern.

[0015] One aspect of the present invention is a method for forming a reversal pattern, comprising: 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; a pattern formation step of developing the exposed resist film to obtain a photoresist pattern; a step of applying a reversal pattern composition so as to cover at least recesses of the photoresist pattern, and etching the resulting coating film to expose the surface of the photoresist pattern; and a step of removing the resist film from the exposed surface portion of the resist pattern to obtain a reversal pattern. [Effects of the Invention]

[0016] When used as a resist composition, the polymer according to some embodiments of the present invention decomposes upon irradiation with particle beams, electromagnetic waves, or the like, converting from ionic to nonionic, resulting in polarity conversion, and simultaneously generating an acid. The generated acid induces an intramolecular crosslinking reaction between the hydroxyl groups in the unit B and / or between the unit A and the unit B. Furthermore, since the anion of the generated acid contains at least one of a hydroxyl group and a sulfanyl group, it reacts with the unit B in the polymer to form the acid of the polymer anion. Therefore, by utilizing the acid of this polymer anion, it is possible to suppress acid diffusion and achieve an intramolecular crosslinking reaction of the polymer without using a bulky anion. As a result, when a pattern is formed using the polymer according to some embodiments of the present invention, the sensitivity and line edge roughness (LWR) characteristics are excellent. DETAILED DESCRIPTION OF THE INVENTION

[0017] In the present invention, the term "particle beam or electromagnetic wave" includes not only electron beam and extreme ultraviolet ray but also ultraviolet ray and the like, but is preferably electron beam or extreme ultraviolet ray. 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. When a portion of a polymer is irradiated with particle beams or electromagnetic waves, a specific portion of the polymer is excited or ionized, 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. The present invention will be specifically described below, but the present invention is not limited thereto.

[0018] <1> polymer The polymer according to some embodiments of the present invention is a polymer comprising an acid-generating unit A having a specific onium salt structure and a unit B having a structure that bonds via an acid-catalyzed reaction.

[0019] A polymer containing the unit A and the unit B is irradiated with particle beams or electromagnetic waves at least in part, whereby the unit A is reduced to generate anions and first radicals from the unit A. Some of the generated anions combine with protons to form acids. The acid acts as a catalyst to cause etherification or thioetherification between the units B and / or between the unit A and the unit B, which can result in a crosslinking reaction. Furthermore, when a unit other than the unit B has at least one of a hydroxyl group and a sulfanyl group, a crosslinking reaction can also occur between at least one of the hydroxyl group and the sulfanyl group of the unit and at least one of the hydroxyl group and the sulfanyl group of the unit B and / or the unit A. A part of the generated acid anion or the anion of unit A can be bonded to at least one of the hydroxyl group and sulfanyl group of the anion and unit B by the acid to form a polymer acid.

[0020] Furthermore, the first radicals generated from the units A can form bonds between themselves and / or between the first radicals and second radicals generated when the polymer contains a radical-generating unit, and an intramolecular crosslinking reaction can occur between the units A and / or between the unit A and a radical-generating unit (e.g., unit C described below).The acid forms a bond between at least one of the hydroxyl group and sulfanyl group of the anion and the unit B, thereby suppressing acid diffusion and resulting in excellent LWR properties for the polymer.

[0021] (Unit A) The unit A has a specific onium salt structure. Specifically, the onium salt structure preferably undergoes polarity conversion upon irradiation of at least a portion of the polymer with particle beams or electromagnetic waves, and the anion portion of the onium salt preferably has an organic group containing at least one of a hydroxyl group and a sulfanyl group. That is, the onium salt structure is not particularly limited as long as it has at least one of a hydroxyl group and a sulfanyl group in the anion portion and generates an acid upon reduction of the onium salt. Specific examples include those represented by the following formula (1): In the present invention, the term "polarity conversion" refers to a change in polarity from ionic to nonionic directly or indirectly due to irradiation with particle beams or electromagnetic waves.

[0022] [ka]

[0023] In the above general formula (1), M + is a sulfonium ion or an iodonium ion, and X -is a monovalent anion having an organic group containing at least one selected from the group consisting of a hydroxyl group and a sulfanyl group.

[0024] L is not particularly limited as long as it can bond the main chain constituting the polymer with the onium salt structure, and examples thereof include 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. As L, a carbonyloxy group or the like is preferred from the viewpoint of ease of synthesis.

[0025] 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 1 to 6 carbon atoms, and at least one methylene group in Sp may be substituted with a divalent heteroatom-containing group.

[0026] 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, and an n-hexylene group. 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, and a 2-ethylhexylene group.

[0027] Examples of the cyclic alkylene group having 1 to 6 carbon atoms represented by 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-, and -N(R Sp )-, -N(Ar Sp )-, -S-, -SO-, and -SO2-. Sp Examples of the alkyl group include linear, branched, or cyclic alkyl groups having 1 to 12 carbon atoms. Sp Examples of the alkylene group include aryl groups having 12 or less carbon atoms, such as a phenyl group and a naphthyl group. The number of carbon atoms in the alkylene group of Sp does not include the number of carbon atoms in any substituent that Sp may have.

[0028] 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 heteroatom-containing group include an alkyl group having one kind of heteroatom-containing group selected from the group consisting of: an aryl group; and a heteroaryl group. Examples of the alkyl group and alkyl group containing a heteroatom-containing group in the skeleton as the first substituent of Sp include alkyl groups in which the alkylene group of Sp is monovalent. The aryl group as the first substituent of Sp includes the above-mentioned Ar Sp The same can be mentioned. 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 forms a spacer structure to facilitate molecular movement, in consideration of the radical rebonding between units A and the crosslinking reaction between units B. Preferred examples include an alkylene group, an alkyleneoxy group, and an alkylenecarbonyloxy group.

[0029] 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 1 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.

[0030] R 1 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. R 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. R 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.

[0031] R 1 Examples of the linear, branched, or cyclic alkenyl group having 1 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 is substituted with a carbon-carbon double bond. Also, R 1The 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. All hydrogen atoms may be substituted with the first substituent. As the fluorinated alkyl group, a trifluoromethyl group or the like is preferred.

[0032] 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, in the above 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 above 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.

[0033] M + is a sulfonium cation or iodonium cation having a bond bonded to Sp, and specific examples thereof include those represented by the following general formulae (a1) and (a2).

[0034] [ka]

[0035] 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 1 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. R 6a Examples of the linear, branched or cyclic alkylene group of include the same alkylene groups as those of Sp. R 6a Examples of the linear, branched or cyclic alkenylene group of include the same as the alkenylene group of Sp.

[0036] R 6a Examples of the arylene group having 6 to 14 carbon atoms include a phenylene group and a naphthylene group. R 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. R 6b The 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 above groups are monovalent.

[0037] R 6a and R 6b Examples of the substituent include the same substituent as the first substituent that may be carried by the above Sp. In the above formula (a1), R 6a and two R 6b Any two of 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. The divalent nitrogen atom-containing group includes, among the divalent hetero atom-containing groups, those containing a nitrogen atom, and specific examples thereof include -NHCO-, -CONH-, -NH-CO-O-, -O-CO-NH-, -NH-, -N(R Sp )- and -N(Ar Sp )- etc.

[0038] M + The sulfonium cation as R is, for example, a compound having the structure shown below and having a bond bonded to the above Sp at any position. 6a and R 6b The portion corresponding to may have a substituent similar to the first substituent.

[0039] [ka]

[0040] X - is a monovalent anion having an organic group containing at least one of a hydroxyl group and a sulfanyl group. The hydroxyl group is preferably derived from any one selected from the group consisting of primary alcohols, secondary alcohols, and tertiary alcohols, and the sulfanyl group is preferably derived from any one selected from the group consisting of primary thiols, secondary thiols, and tertiary thiols. From the steric viewpoint of bonding to the unit B, the hydroxyl group is more preferably derived from any one selected from the group consisting of a primary alcohol, a secondary alcohol, a primary thiol, and a secondary thiol. In view of reactivity with unit B in the presence of an acid catalyst, it is preferable that the hydroxyl group is not a phenolic hydroxyl group.

[0041] X -is preferably any one selected from the group consisting of: an alkyl sulfate anion having at least one hydroxyl group and a sulfanyl group; an aryl sulfate anion having at least one hydroxyl group and a sulfanyl group; an alkyl sulfonate anion having at least one hydroxyl group and a sulfanyl group; an aryl sulfonate anion having at least one hydroxyl group and a sulfanyl group; an alkyl carboxylate anion having at least one hydroxyl group and a sulfanyl group; an aryl carboxylate anion having at least one hydroxyl group and a sulfanyl group; a dialkylsulfonylimide anion having at least one hydroxyl group and a sulfanyl group; and a trialkylsulfonate methide anion having at least one hydroxyl group and a sulfanyl group; and a tetrakisphenylborate anion having at least one hydroxyl group and a sulfanyl group.

[0042] Also, X - At least one hydrogen atom of the alkyl group and aryl group in the unit B may be substituted with a fluorine atom and / or an iodine atom, but from the viewpoint of reactivity in bonding with the unit B, it is preferable that the number of fluorine and iodine atom substitutions is as small as possible. X - is more preferably either an alkylsulfonate anion having at least one hydroxyl group and one sulfanyl group or an arylsulfonate anion having at least one hydroxyl group and one sulfanyl group, wherein at least one hydrogen atom of the alkyl group of the alkylsulfonate anion or the aryl group of the arylsulfonate anion may be substituted with a fluorine atom.

[0043] The alkyl sulfate anion having at least one hydroxyl group preferably has 1 to 12 carbon atoms. The alkyl sulfate anion having at least one sulfanyl group preferably has 1 to 12 carbon atoms. The alkyl sulfate anion may have multiple hydroxyl groups and sulfanyl groups.

[0044] The aryl sulfate anion having at least one hydroxyl group preferably has 4 to 12 carbon atoms. The aryl sulfate anion having at least one sulfanyl group preferably has 4 to 12 carbon atoms. The aryl sulfate anion may have multiple hydroxyl groups and sulfanyl groups.

[0045] The alkylsulfonate anion having at least one hydroxyl group preferably has 1 to 12 carbon atoms. The alkylsulfonate anion having at least one sulfanyl group preferably has 1 to 12 carbon atoms. The alkylsulfonate anion may have a plurality of hydroxyl groups and sulfanyl groups.

[0046] The arylsulfonate anion having at least one hydroxyl group preferably has 4 to 12 carbon atoms. The arylsulfonate anion having at least one sulfanyl group preferably has 4 to 12 carbon atoms. The arylsulfonate anion may have a plurality of hydroxyl groups and sulfanyl groups.

[0047] The alkylcarboxylate anion having at least one hydroxyl group preferably has 2 to 12 carbon atoms. The alkylcarboxylate anion having at least one sulfanyl group preferably has 2 to 12 carbon atoms. The alkylcarboxylate anion may have multiple hydroxyl groups and sulfanyl groups.

[0048] The arylcarboxylate anion having at least one hydroxyl group preferably has 5 to 12 carbon atoms. The arylcarboxylate anion having at least one sulfanyl group preferably has 5 to 12 carbon atoms. The arylcarboxylate anion may have multiple hydroxyl groups and sulfanyl groups.

[0049] The dialkylsulfonylimide anion having at least one hydroxyl group preferably has 1 to 12 carbon atoms. The dialkylsulfonylimide anion having at least one sulfanyl group preferably has 1 to 12 carbon atoms. The dialkylsulfonylimide anion may have a plurality of hydroxyl groups and sulfanyl groups.

[0050] The trialkylsulfonate methide anion having at least one hydroxyl group preferably has 1 to 12 carbon atoms. The trialkylsulfonate methide anion having at least one sulfanyl group preferably has 1 to 12 carbon atoms. The trialkylsulfonate methide anion may have a plurality of hydroxyl groups and sulfanyl groups.

[0051] The tetrakisphenylborate anion having at least one hydroxyl group preferably has 25 to 30 carbon atoms. The tetrakisphenylborate anion having at least one sulfanyl group preferably has 25 to 30 carbon atoms. The tetrakisphenylborate anion may have a plurality of hydroxyl groups and sulfanyl groups.

[0052] Above X - Examples of such compounds include those shown below.

[0053] [ka]

[0054] The unit A is preferably one represented by the following formula (3).

[0055] [ka]

[0056] In the above general formula (IV), L, Sp and X - represents L, Sp and X in the general formula (1). - and R 6a and R 6b is R in the above general formula (a1). 6a and R 6b are similar to each of the above.

[0057] Furthermore, the polymer according to one embodiment of the present invention is a polymer having M + X - Preferably, the polymer has a unit A having an onium salt structure represented by the following general formula (11) or the following formula (12). When a polymer having this structure is used in a resist composition, it is preferable to irradiate the resist composition with the particle beam or electromagnetic wave (hereinafter also referred to as "first active energy ray"), followed by exposure to second active energy ray having lower energy than the first active energy ray. The second active energy ray is preferably ultraviolet light or visible light. The resist composition uses a polymer including a unit A having a specific onium salt structure with an acetal moiety or a thioacetal moiety (hereinafter also referred to as "acetal moiety or thioacetal moiety") and a unit B having a structure that bonds via an acid-catalyzed reaction. When the resist composition containing the polymer is irradiated with the first active energy ray, the onium salt structure of the unit A decomposes and an acid is generated. When the onium salt structure of the unit A in the composition irradiated with the first actinic energy ray using this acid as a catalyst has a (thio)acetal moiety, the acid causes a structural change and the ketone derivative is converted into a ketone derivative that absorbs the second actinic energy ray. By exposing the composition in which the ketone derivative has been generated to the second actinic energy ray, acid is generated with high efficiency, resulting in high sensitivity.

[0058] In the unit A related to the polymer that is one embodiment of the present invention, the onium salts of the general formulae (11) and (12) have a specific structure of a (thio)acetal moiety and a dibenzothiophenium skeleton, and therefore have high decomposition efficiency with respect to the first active energy ray and high absorption with respect to irradiation with the second active energy ray after irradiation with the first active energy ray. Furthermore, when the onium salt structure of unit A in a polymer according to one embodiment of the present invention is an onium salt structure represented by the general formulas (11) and (12), unit A does not exhibit significant absorption of the second active energy ray, such as ultraviolet light or visible light. Meanwhile, the acid generated by the first active energy ray deprotects the (thio)acetal moiety of the onium salt structure, converting it to a ketone derivative without impairing the onium salt structure's function as a photoacid generator. The ketone derivative contains a dibenzothiophenium structure having a fused ring structure, which increases the conjugation length, thereby easily shifting the absorption wavelength to a longer wavelength and absorbing the second active energy ray. Since the ketone derivative is generated in the resist film in the exposed area irradiated with the first active energy ray, further irradiation with the second active energy ray can increase the amount of acid generated in the exposed area irradiated with the first active energy ray. In the present invention, the second active energy ray is preferably ultraviolet light or visible light having a wavelength of 365 nm or more. The second active energy ray is more preferably 420 nm or less. The first active energy ray preferably has higher energy than the second active energy ray and is not particularly limited as long as it can generate an active species such as an acid from the onium salt of unit A. Preferred examples of the first active energy ray include KrF excimer laser light, ArF excimer laser light, electron beams, and extreme ultraviolet light (EUV).

[0059] [ka] [ka]

[0060] In the above formulas (11) and (12), the R 14 are each independently any one selected from the group consisting of an alkyl group, a hydroxy group, a mercapto group, an alkoxy group, an aryloxycarbonyl group, a heteroaryloxycarbonyl group, an arylsulfanylcarbonyl group, a heteroarylsulfanylcarbonyl group, an arylsulfanyl group, a heteroarylsulfanyl group, an alkylsulfanyl group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group, a (poly)alkyleneoxy group, an alkylamino group, and a dialkylamino group. R 17 and R 18 are each independently any one selected from the group consisting of an alkyl group, a hydroxy group, a mercapto group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, a heteroarylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a heteroaryloxycarbonyl group, an arylsulfanylcarbonyl group, a heteroarylsulfanylcarbonyl group, an arylsulfanyl group, a heteroarylsulfanyl group, an alkylsulfanyl group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group, an alkylsulfinyl group, an arylsulfinyl group, a heteroarylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a heteroarylsulfonyl group, an arylsulfonyl group, a heteroarylsulfonyl group, a (poly)alkyleneoxy group, an alkylamino group, a dialkylamino group, a nitro group, and a halogen atom. Above R 14 , R 17 and R 18 When R has carbon atoms, the number of carbon atoms is 1 to 12, and 14 , R 17 and R 18 When has a hydrogen atom, the hydrogen atom may be substituted with a substituent (hereinafter also referred to as a "second substituent").

[0061] R 14 , R 17 and R 18The alkyl group in may be linear, branched, or cyclic. Specifically, R e The alkyl groups of R 14 , R 17 and R 18 The alkyl group moiety of the alkoxy group, alkylcarbonyl group, alkoxycarbonyl group, etc. in R 1 The alkyl groups in the above formula (I) are the same as those in the above formula (I). R 14 , R 17 and R 18 The aryl and heteroaryl groups in 19 The aryl and heteroaryl groups are the same as those in R 17 and R 18 The aryl group moiety such as the arylcarbonyl group and aryloxycarbonyl group in 19 The aryl groups in R 17 and R 18 The heteroaryl group moiety such as the heteroarylcarbonyl group and heteroaryloxycarbonyl group in R 1 The heteroaryl groups in R 17 and R 18 In terms of synthesis, it is preferable that the substituent does not have a heteroaryl group moiety such as the heteroarylcarbonyl group or heteroaryloxycarbonyl group. The onium salt structures represented by the above formulas (11) and (12) are R 14 When there are two or more 14 Two of these may be linked to each other to form a ring structure.

[0062] R 14 , R 17 and R 18 Examples of the (poly)alkyleneoxy group in the formula include a polyethyleneoxy group and a polypropyleneoxy group. R 17 and R 18 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and an iodine atom.

[0063] R 14 , R 17 and R 18 When R has carbon atoms, the number of carbon atoms is preferably 1 to 12, and these may have a second substituent. 2 , R 3 and R 4 The carbon-carbon single bond in the alkyl group may be replaced with a carbon-carbon double bond. R 14 , R 17 and R 18 The second substituent that may be possessed by the group is a hydroxy group, a cyano group, a mercapto group, a carboxy group, an alkyl group (-R e ), alkoxy group (-OR e ), acyl group (-COR e ), alkoxycarbonyl group (-COOR e ), aryl group (-Ar), aryloxy group (-OAr), amino group, alkylamino group (-NHR e ), dialkylamino group (-N(R e )2), arylamino group (-NHAr), diarylamino group (-N(Ar)2), N-alkyl-N-arylamino group (-NR e Ar) phosphino group, silyl group, halogen atom, 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. R e and Ar are explained below.

[0064] The R in the second substituent eis preferably an alkyl group having 1 or more carbon atoms. It is more preferably one having 20 or fewer 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; branched alkyl groups such as isopropyl, isobutyl, tert-butyl, isopentyl, tert-pentyl, and 2-ethylhexyl; alicyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantan-1-yl, adamantan-2-yl, norbornan-1-yl, and norbornan-2-yl; 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.

[0065] Ar in the second substituent is preferably an aryl group or a heteroaryl group. A heteroaryl group is an aryl group containing one or more heteroatoms in the ring structure. Specific examples of Ar include those having 20 or less carbon atoms, such as 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 imidazoyl group, an oxazolyl group, a thiazolyl group, a pyrazoyl group, a pyridyl group, an isobenzofuranyl group, a benzofuranyl group, an isochromenyl group, a chromenyl group, an indolyl group, an isoindolyl group, a benzimidazoyl group, a xanthenyl group, an aquadinyl group, and a carbazoyl group.

[0066] R 14 , R 17 and R18 When R has the second substituent, 14 , R 17 and R 18 The number of carbon atoms in the second substituent is preferably 1 to 12, including the number of carbon atoms in the second substituent.

[0067] The onium salt structure of the polymer according to one embodiment of the present invention is R 14 It is preferable that the compound has at least one R 14 is preferably a hydroxy group or an alkoxy group. 14 is preferably in the ortho or para position relative to the bonding position of the (thio)acetal moiety. 14 When the compound has a hydroxy group or an alkoxy group at the ortho- or para-position as the hydroxyl group, the compound tends to absorb more of the second actinic ray when it becomes a ketone derivative. In particular, a hydroxy group is more preferable because it improves the affinity for an alkaline developer and improves the solubility of the onium salt during development. Generally, when a substituent is added to the cation of the onium salt structure, the onium salt cation structure becomes three-dimensionally larger, which may improve hydrophobicity and cause a dissolution inhibition effect during development. Therefore, it is preferable to have a structure in which the absorption wavelength of the ketone derivative after deprotection of the (thio)acetal moiety is longer without having a hydrophobic substituent that tends to have low affinity to alkaline developers, thereby increasing the absorption of the second actinic ray. Furthermore, since a substituent exhibiting basicity deactivates the generated acid and inhibits the decomposition of the acid-dissociable group, it is not preferable to introduce a substituent exhibiting basicity. For these reasons, the cation of the onium salt structure in the polymer, which is one embodiment of the present invention, is R 14 , R 17 and R 18 It is preferable that R does not have a substituent containing an aromatic ring or an alicyclic structure, and does not have a basic group such as an amino group that reacts with the generated acid, and it is also preferable that the molecular weight of the cation portion of the onium salt structure is 500 or less. 14 Including R 17 and R18 It is more preferable that the hydroxyl group does not have a basic group such as an amino group. R 14 If there are multiple 14 At least one of R is preferably a hydroxy group or an alkoxy group, and is preferably located at the ortho or para position relative to the bonding position of the (thio)acetal moiety. 14 If there are multiple 14 If at least one of R is a hydroxy group or an alkoxy group, the other R 4 may not be a hydroxy group or an alkoxy group. In order to increase the absorption wavelength of the ketone derivative produced by the acid, two or more R 14 More preferably, R is a substituent that donates an electron to the aromatic ring to which R is bonded. Even more preferably, R is bonded to two or more positions that are ortho- or para-positions relative to the bonding position of the (thio)acetal moiety. 14 It is preferable that the alkyl group has a hydroxy group or an alkoxy group.

[0068] R 19 is any one 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 1 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.

[0069] R 19 Specific examples of the linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms in the formula (I) include alkyl groups such as methyl, ethyl, n-propyl, n-butyl, isopropyl, t-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantan-1-yl, adamantan-2-yl, norbornan-1-yl, and norbornan-2-yl.

[0070] R 19In the alkyl group, at least one methylene group 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 e )-, -N(Ar)-, -S-, -SO-, and -SO2-. However, the sulfur atom (S + ) is preferably not directly bonded to the heteroatom-containing group but is bonded to a divalent hydrocarbon group. e and Ar will be described later. R 19 Examples of the alkenyl group include those in which at least one carbon-carbon single bond of the alkyl group is substituted with a carbon-carbon double bond.

[0071] R 19 Specific examples of the aryl group having 6 to 14 carbon atoms which may have a substituent include monocyclic aromatic hydrocarbon groups and condensed polycyclic aromatic hydrocarbon groups in which at least two of the monocyclic aromatic hydrocarbons are condensed. These aryl groups may have a substituent. Examples of the monocyclic aromatic hydrocarbon group include groups having a skeleton such as benzene. Examples of the condensed polycyclic aromatic hydrocarbon group include groups having a skeleton such as indene, naphthalene, azulene, anthracene, and phenanthrene.

[0072] R 19 Examples of the heteroaryl group having 4 to 12 carbon atoms which may have a substituent include those which contain at least one atom selected from an oxygen atom, a nitrogen atom and a sulfur atom in the skeleton, instead of at least one carbon atom of the above aryl group.

[0073] Examples of the heteroaryl group include monocyclic aromatic heterocyclic groups and fused polycyclic aromatic heterocyclic groups in which at least one of the monocyclic aromatic heterocyclic rings is fused with the aromatic hydrocarbon group or aliphatic heterocyclic group, etc. These aromatic heterocyclic groups may have a substituent. Examples of the monocyclic aromatic heterocyclic group include groups having a skeleton such as furan, pyrrole, imidazole, pyran, pyridine, pyrimidine, and pyrazine.

[0074] Examples of the fused polycyclic aromatic heterocyclic group include groups having a skeleton such as indole, purine, quinoline, isoquinoline, chromene, phenoxazine, xanthene, acridine, phenazine, and carbazole.

[0075] R 19 Examples of the substituent in (hereinafter also referred to as "third substituent") include the same as the second substituent described above.

[0076] R 19 When the alkyl group or the like of R 19 The number of carbon atoms in the group is preferably 1 to 20, including the number of carbon atoms in the third substituent.

[0077] Above R 19 And the above R 2 is bonded to the benzene ring and the above R 3 may form a ring structure together with any of the benzene rings to which is bonded, either directly via a single bond or via a sulfur atom to which is bonded, through any one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group and a methylene group, Examples of the "nitrogen atom-containing group" include an aminodiyl group (-NH-), an alkylaminodiyl group (-NR e Examples of divalent groups containing a nitrogen atom include a divalent group containing a nitrogen atom, such as an arylaminodiyl group (-NAr-) and an arylaminodiyl group (-NAr-). e and for Ar, R of the third substituent e and Ar.

[0078] R19 As the alkyl group, an aryl group is preferred from the viewpoint of improving stability.

[0079] Above R 19 And the above R 18 is bonded to the benzene ring and the above R 17 may form a ring structure together with any of the benzene rings to which is bonded, either directly through a single bond or via a sulfur atom to which is bonded, through any group selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group, and a methylene group.

[0080] Above R 14 , R 17 and R 18 When R has methylene groups, at least one of the methylene groups may be substituted with a divalent heteroatom-containing group. However, it is preferable that there is no continuous linkage of heteroatoms such as -OO-, -SS-, and -OS-. When R has methylene groups, at least one of the methylene groups may be substituted with a divalent heteroatom-containing group, 14 , R 17 and R 18 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.

[0081] Above R 15 and R 16 are each independently preferably 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 1 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, which are the same as or different from the above R 19Preferably, each of the above is selected from the same options. R 15 and R 16 Examples of the substituent as the second substituent include the same as those described above for the second substituent. Above R 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, Above R 15 and R 16 At least one methylene group therein may be substituted with a divalent heteroatom-containing group. From a synthetic point of view, the above R 15 and R 16 are preferably the same.

[0082] L 3 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; a sulfinyl group, a sulfonyl group and a carbonyl group.

[0083] R 14 , R 18 and R 19 Any one hydrogen atom in is replaced by a bond with Sp in the above general formula (1).

[0084] Y is an oxygen atom or a sulfur atom.

[0085] q is an integer of 0 to 4, f is an integer of 0 to 3, g is an integer of 1 to 5, j is an integer of 0 to 2, and k is an integer of 1 to 4. However, the above R 19 And the above R 18 is bonded to the benzene ring and the above R 17 When any of the benzene rings to which is bonded forms a ring structure together with the sulfur atom, q is 0 to 3 or j is 0 to 2 in the general formula (11), and q is 0 to 3 or j is 0 to 1 in the general formula (12). At least one of the benzene rings in the general formulas (11) and (12) may be a 6-membered heteroaromatic ring having a heteroatom in the ring, and R 14 When the benzene ring bonded to the heteroaromatic ring is the above-mentioned heteroaromatic ring, k may be 0 to 4. In the above general formulas (11) and (12), R 14 When there are two or more 14 Two of these may be linked to each other to form a ring structure. X - is X in the above general formula (1). - are selected from the same options.

[0086] In some embodiments of the polymer of the present invention, the onium salt structure contained in unit A can be exemplified by one having the sulfonium cation shown below. The wavy line in the sulfonium cation shown below indicates the bonding site with Sp in formula (1) above, and when there are multiple wavy lines in the same structure, any one of them is bonded to the above Sp. However, some embodiments of the present invention are not limited to this.

[0087] [ka]

[0088] The anion of the unit A is preferably highly hydrophilic in order to improve contrast during photoresist pattern formation. Specific examples include alkyl sulfate anions, aryl sulfate anions, alkyl sulfonate anions, aryl sulfonate anions, alkyl carboxylate anions, and aryl carboxylate anions. These anions have at least one hydroxyl group and one sulfanyl group.

[0089] The polymer according to one embodiment of the present invention may have two or more types of the unit A. For example, it is preferable to use one as a photoacid generator unit A (hereinafter also referred to as "unit A1") and the other as a photodegradable base unit A (hereinafter also referred to as "unit A2"). X of the photodegradable base unit A2 - is preferably an alkyl carboxylate anion or an aryl carboxylate anion. The photodegradable base unit A2 is preferably used in combination with the photoacid generator unit A1. The polymer containing unit A2 has the effect of reducing the LWR, which is effective when high resolution is required. In addition, when the polymer contains two or more types of the unit A, M + X - The parts are the same and R 1 Units having different substituents such as , and L may also be used.

[0090] The onium salts related to the polymers of some embodiments of the present invention have 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 More preferably, it is less than 1 / mol. In addition, the ketone derivative obtained by deprotecting the (thio)acetal moiety of the onium salt according to some embodiments of the present invention has a molar absorption coefficient of 1.0×10 at 365 nm. 5 cm 2 / mol or more, and 1.0 × 10 6 cm 2 / mol or more is more preferable. The molar absorption coefficient at 365 nm of the ketone derivative is preferably at least 5 times, more preferably at least 10 times, and even more preferably at least 20 times the molar absorption coefficient at 365 nm of the onium salt related to the polymer according to some embodiments of the present invention. To achieve the above properties, an onium salt represented by the above formula (11) or (12) may be used.

[0091] (Method for synthesizing monomer for unit A) A method for synthesizing the sulfonium salt structure contained in unit A of the polymer, which is one embodiment of the present invention, will be described below, although the present invention is not limited thereto.

[0092] In the case of a (meth)acrylate monomer in which the target sulfonium salt structure does not contain a (thio)acetal moiety, for example, the synthesis method shown below can be used. 6b Diaryl sulfoxides having a group and benzenes having a hydroxyl group (R 6a The Friedel-Crafts reaction of the above R with a Bronsted acid yields a hydroxyaryldiaryl sulfoxide. The desired sulfonium salt is then obtained using a basic catalyst and (meth)acrylic acid chloride. 1 , R 6a and R 6b is a substituent other than those exemplified here, but may be any of the above-mentioned R 1 , R 6a and R 6b can be obtained in the same manner within the range.

[0093] [ka]

[0094] When the target sulfonium salt structure is a vinyl or isopropenyl monomer that does not contain a (thio)acetal moiety, for example, the synthesis method shown below can be used. First, R 6b Diaryl sulfoxides bearing a vinyl or isopropenyl group and Grignard reagents (R 6a group) to R 6b After reacting with a sulfoxide having a group to form a sulfonium salt structure, the target sulfonium salt structure is obtained by salt exchange with a salt having the corresponding anion. 1 , R 6a and R 6b is a substituent other than those exemplified here, but may be any of the above-mentioned R1 , R 6a and R 6b can be obtained in the same manner within the range.

[0095] [ka]

[0096] When the target sulfonium salt structure contains a (thio)acetal moiety, for example, the synthesis method shown below can be used. 17 Groups and R 18 Dibenzothiophene having a group and optionally R 14 The benzoyl chloride (i = 1 in the formula below) is subjected to a Friedel-Crafts reaction using a Lewis acid to obtain a benzophenone derivative. The sulfide is then oxidized to a sulfoxide, and the benzene with a hydroxyl group and a Brønsted acid are then subjected to a Friedel-Crafts reaction to obtain a sulfonium, which is then converted to an alcohol (R 15 The carbonyl group is acetalized using (OH). Then, the desired oninium salt is obtained using a basic catalyst and (meth)acrylic acid chloride. 14 , R 15 , R 17 and R 18 is a substituent other than those exemplified here, but may be any of the above-mentioned R 14 , R 15 , R 17 and R 18 can be obtained in the same manner within the range.

[0097] [ka]

[0098] When the target sulfonium salt structure contains a (thio)acetal moiety, for example, the synthesis method shown below can be used. 17 Groups and R 18 Dibenzothiophene having a group and optionally R 14The benzoyl chloride (i = 1 in the formula below) is subjected to a Friedel-Crafts reaction using a Lewis acid to obtain a benzophenone derivative. The sulfide is then oxidized to a sulfoxide, and the benzene with a hydroxyl group is then subjected to a Friedel-Crafts reaction with a Brønsted acid to obtain a sulfonium, followed by the addition of an alcohol (R 15 The carbonyl group is acetalized using a Grignard reagent, which then converts it into a sulfonium salt structure, followed by salt exchange with a salt containing the corresponding anion to obtain the desired sulfonium salt structure.

[0099] [ka]

[0100] (Unit B) The unit B is not particularly limited as long as it has a structure that allows two molecules to bond together via an acid-catalyzed reaction. For example, a unit in which a compound represented by the general formula (I) or (II) is bonded to the Sp group of the formula (1) at any position of the compound is preferred. At least one of the compounds represented by the following general formula (I) or (II) is bonded at any position of the compound to the moiety * in the following formula (2) and contained in the polymer as unit B. When the polymer contains unit B, it becomes possible to improve sensitivity to particle beams or electromagnetic waves.

[0101] [ka]

[0102] [ka]

[0103] In the above formula (2), R 1 , L and Sp are the same as in the general formula (1) above.

[0104] In the above general formula (I), R2 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 At least one of the groups is preferably an 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.

[0105] n 1 is an integer of 0 or 1. 4 and n 5 are integers between 1 and 2. 4 +n 5 is 2 to 4. n 4 When is 1, n 2 is an integer between 0 and 4. 4 When is 2, n 2 is an integer between 0 and 6. n 5 When is 1, n 3 is an integer between 0 and 4. 5 When is 2, n 3 is an integer between 0 and 6. n 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. n 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. In the above formula (I), examples of the divalent nitrogen atom-containing group for forming a ring structure include the same as the divalent nitrogen atom-containing group in the above formula (a1).

[0106] In the above general formula (II), R 4 are each independently any one selected from the group consisting of a hydrogen atom, an electron-donating group, and an electron-withdrawing group. 4 At least one of the groups is preferably an electron-donating group, since this improves the acid reactivity. R 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 therein may be substituted with a divalent heteroatom-containing group. Also, R 5 is the R 5 may form a ring structure together with the benzene ring to which the hydroxymethylene group having the formula:

[0107] R 5 The alkyl group in R may be a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms. 6b The alkyl groups may be the same as those mentioned above. R 5 Examples of the substituent that Sp has include the same as the first substituent that Sp has.

[0108] n 6 is an integer from 0 to 7, n 7 is 1 or 2. n 7 When n6 is 1, n6 is an integer between 0 and 5. 7 When is 2, n 6 is an integer between 0 and 7.

[0109] 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. In the above formula (II), examples of the divalent nitrogen atom-containing group for forming a ring structure include the same as the divalent nitrogen atom-containing group in the above formula (a1).

[0110] R 2 , R 3 and R 4 The electron donating group in 13 ), the alkyl group (-R 13 an alkenyl group in which at least one carbon-carbon single bond of the above group is replaced by 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. 13 ) and alkylthio groups (-SR 13 ); etc.

[0111] Above R 13 is preferably an alkyl group having one or more carbon atoms. Specific preferred examples of the alkyl group having one 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 of these alkyl 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 hydrogen atom of a carbon atom that is not directly bonded to the aromatic ring of compound (I) or (II) is substituted with a cyano group, a fluoro group, or the like. Above R 13 It is preferable that the number of carbon atoms is 4 or less.

[0112] R 2 , R 3 and R 4As the electron-withdrawing group of -C(=O)R 13a (R 13a represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms which may have a substituent; —C(═O)R 13b (R 13b represents an aryl group having 6 to 14 carbon atoms which may have a substituent; —C(═O)OR 13a ;-SO2R 13a ;-SO2R 13b ; Nitro group; Nitroso group, trifluoromethyl group, -OR substituted in the meta position relative to the hydroxyl group 13a -OR substituted at the meta position relative to the hydroxyl group 13b ; -SR substituted at the meta position relative to the hydroxyl group 13a ; -SR substituted at the meta position relative to the hydroxyl group 13b ; and the above -C(=O)R 13a , -C(=O)OR 13a , -SO2R 13a and -SR 13a a group in which at least one carbon-carbon single bond is replaced with a carbon-carbon double bond or a group in which at least one carbon-carbon single bond is replaced with a carbon-carbon triple bond; and the like. R 13a and R 13b Examples of the substituent that may be possessed by include the same as the first substituent that may be possessed by the above Sp.

[0113] Specific examples of the compounds represented by the above general formula (I) or (II) include those shown below.

[0114] [ka]

[0115] One embodiment of the polymer of the present invention is a polymer in which either of the compounds represented by the general formula (I) or (II) is contained in the polymer as unit B bonded to the * portion of formula (2) at any position of the compound. In this case, the position of bonding to the * portion of formula (2) is R 2 , R 3 and R 4For 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 * portion of the formula (2) above.

[0116] The unit B 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, in the above 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. The polymer according to one embodiment of the present invention may have two or more types of the unit B in the polymer.

[0117] (Unit C) The above-mentioned unit C is a unit having a radical-generating structure containing at least one multiple bond selected from the group consisting of a multiple bond between carbon atoms and a multiple bond between a carbon atom and a heteroatom, and is not particularly limited as long as it generates a second radical when at least a part of the polymer is irradiated with a particle beam or electromagnetic wave. An intramolecular crosslinking reaction can occur between the unit A and the unit C by irradiation with particle beams, electromagnetic waves, or the like. The multiple bond in the unit C is not particularly limited as long as it generates a radical cation under the influence of particle beams or electromagnetic waves and the radical cation decomposes into a second radical and a cation, but it is preferably not one contained in a benzene-based aromatic and at least one of the bonds shown below. Benzene-based aromatics include not only benzene but also aromatics having a benzene skeleton such as naphthalene and azulene. "Not a multiple bond contained in a benzene-based aromatic" means that it is not a multiple bond contained in these aromatics.

[0118] [ka]

[0119] Specific examples of the radical-generating structure containing a multiple bond include units having any one selected from the group consisting of an alkylphenone skeleton, an acyloxime skeleton, and a benzyl ketal. As long as the structure has these skeletons, any substituent may be included, and examples of units having an alkylphenone skeleton include an α-aminoacetophenone skeleton. More specifically, preferred examples include those represented by at least one of the following general formulas (4):

[0120] [ka]

[0121] In the above general formula (4), R 1 L and Sp are the same as L and Sp in the general formula (1) above. R 7 are each independently a hydrogen atom; a hydroxy group; -R a (R a represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms which may have a substituent; -OR a and the R a a group in which at least one carbon-carbon single bond in -R is replaced with a carbon-carbon double bond; and -R b (R bis an aryl group having 6 to 14 carbon atoms which may have a substituent; and 3 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. R a As for R 13a The alkyl groups are the same as those in the alkyl groups of R b As for R 13b Examples of the aryl group include the same as those of the aryl group in the above.

[0122] R a and R b Examples of the substituent that may be possessed by include the same as the substituent that may be possessed by the above Sp. However, in the above formula (4), R 7 It is preferable that the three R 7 Preferably, at least one of the units is OH. By having OH as the unit C, a crosslinking reaction can occur between the unit B and the unit C.

[0123] R 8 -R a ;-R b ;-OR a ;-SR a ;-OR b ;-SR b ;-OC(=O)R a ;-OC(=O)R b ;-C(=O)OR a ;-C(=O)OR b ;-OC(=O)OR a ;-OC(=O)OR b ;-NHC(=O)R a ;-NR a C(=O)R a ;-NHC(=O)R b ;-NR b C(=O)R b ;-NR a C(=O)R b ;-NR b C(=O)Ra ;-N(R a )2;-N(R b )2;-N(R a )(R b );-SO3R a ;-SO3R b ;-SO2R a ;-SO2R b ;s-R a a group in which at least one carbon-carbon single bond is replaced with a carbon-carbon double bond; and a nitro group. In the above formula (4), m 1 When is 2 or more, two R 8 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.

[0124] m 2 is an integer from 1 to 3, and m 2 When is 1, m 1 is an integer from 0 to 4, and m 2 When is 2, m 1 is an integer from 0 to 6, and m 2 When is 3, m 1 is an integer between 0 and 8.

[0125] 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 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. The polymer according to one embodiment of the present invention may have two or more types of the unit C in the polymer.

[0126] (Unit D) In one embodiment of the present invention, the polymer preferably further contains a unit having an aryloxy group (hereinafter also referred to as "unit D") in addition to the above units A to C. As the unit D, a unit in which a phenol structure is bonded to the * portion of the above formula (2) at any position of the phenol structure is preferred. There are no particular limitations on the unit D as long as it can improve the efficiency of generating the acid generated by the unit A. Specific examples include the units shown below.

[0127] [ka]

[0128] In the above general formula, R 11 Each of R is preferably independently any one selected from the group consisting of a hydrogen atom and an alkyl group. 11 The alkyl group may have a substituent. Examples of the alkyl group include linear or branched alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, isopropyl, n-isopropyl, sec-butyl, tert-butyl, n-butyl, and pentyl groups. 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. R 11 Examples of the substituent that may be possessed by include the same as the first substituent that may be possessed by the above Sp. In the above formula, two or more R 11 is not a hydrogen atom, 11 Two R are not hydrogen atoms 11may 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. n 8 is 4.

[0129] Specific examples of unit D include those composed of a monomer such as 4-hydroxyphenyl(meth)acrylate. When the polymer contains the unit D, it becomes possible to improve the efficiency of acid generation.

[0130] The unit D is preferably R 1 is a hydrogen atom or a linear alkyl group, and L is a carbonyloxy group or a phenylenediyl group. In addition, as the unit D, 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. The polymer according to one embodiment of the present invention may have two or more types of the unit D in the polymer.

[0131] (Unit E) In one embodiment of the present invention, the polymer preferably further contains, in addition to the above units A to D, an organometallic compound-containing unit E (hereinafter also referred to as "unit E") having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi, and Te. The metal atom contained in the unit E 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. The unit E 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 (2) at any position of the structure. Unit E has a high efficiency of generating secondary electrons upon EUV irradiation, and can increase the decomposition efficiency of the above-mentioned units A and B. There are no particular limitations on unit E as long as it contains the above-mentioned metal atom that has high EUV absorption, and specific examples include the units shown below.

[0132] [ka]

[0133] 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 may have a substituent. Examples of the alkyl group include linear or branched alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, isopropyl, n-isopropyl, sec-butyl, tert-butyl, n-butyl, and pentyl groups. 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, 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. In the above formula, two R 12b 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. n 9 is an integer between 0 and 4.

[0134] 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 1 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. R 12b The straight-chain, branched or cyclic alkyl group of R 2b The alkyl groups are the same as those mentioned above. 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.

[0135] 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 Examples of the heteroaryl group include the same as the heteroaryl group of the above. Two or more R's 12a may form a ring structure directly with 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 may be bonded to each other to form a ring structure together with the metal atom to which they are bonded. R 12a and R 12b Examples of the substituent that may be possessed by include the same as the first substituent that may be possessed by the above Sp.

[0136] Specific examples of unit E include units formed from 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. When the polymer contains the unit E, it becomes possible to improve the efficiency of generating secondary electrons when irradiated with particle beams or electromagnetic waves.

[0137] The unit E is preferably R 1 is a hydrogen atom or a linear alkyl group, and L is a carbonyloxy group or a phenylenediyl group. In addition, as the unit E, 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. The polymer according to one embodiment of the present invention may have two or more types of the unit E in the polymer.

[0138] (Unit F) In one embodiment of the present invention, the polymer preferably further comprises a unit F having a halogen atom and represented by the following formula (7):

[0139] [ka]

[0140] In the above general formula (7), R 1 , L and Sp are R in the above general formula (2), 1 , L and Sp are preferably selected from the same options. R h is 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 alkyleneoxy group having 1 to 12 carbon atoms; an optionally substituted linear, branched, or cyclic alkenyl group having 1 to 12 carbon atoms; an optionally substituted linear, branched, or cyclic alkenyleneoxy group having 1 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; and some or all of the hydrogen atoms substituted on the carbon atoms are substituted with fluorine atoms or iodine atoms. R h Examples of the alkyl group, alkenyl group, alkylene group of the alkyleneoxy group, alkenylene group of the alkenyleneoxy group, aryl group, and heteroaryl group are the same as those described above for Sp. The substituents for these groups are the same as those for Sp.

[0141] Specific examples of unit F include units obtained from the following monomers.

[0142] [ka]

[0143] The unit F is preferably R 1is 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 F, 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. The polymer according to one embodiment of the present invention may have two or more types of the unit F in the polymer.

[0144] (Other units) In one embodiment of the present invention, the polymer may contain, in addition to the above units A to F, units that are commonly used in resist compositions, as long as the effects of the present invention are not impaired. For example, there is mentioned a unit (hereinafter also referred to as "unit G") having a skeleton containing an ether group, a lactone skeleton, an ester group, a hydroxy group, an epoxy group, a glycidyl group, an oxetanyl group, or the like at the * portion of the above formula (2). Further, a unit having a skeleton with an alcoholic hydroxy group at the position * in the formula (2) (hereinafter also referred to as "unit H") is exemplified. The unit H is different from the units A to G. The inclusion of the unit H in the polymer is preferred because it tends to increase the rate of intramolecular crosslinking reactions. A unit having a skeleton containing an epoxy group, a glycidyl group, an oxetanyl group, or the like is preferred because cationic polymerization can occur when a strong acid is used as the acid generated from the unit A.

[0145] The polymer according to one embodiment of the present invention may have a unit I represented by the following general formula (8): Unit I is a unit different from the above units A to H. When the polymer according to one embodiment of the present invention has unit I, the polymer main chain is more likely to be cleaved by the action of radicals generated by irradiation with particle beams or electromagnetic waves, thereby shortening the polymer chain at the exposure boundary and reducing the LWR.

[0146] [ka]

[0147] In the above general formula (8), each substituent is preferably as follows. R 10 is any one selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched, or cyclic alkenyl group having 1 to 6 carbon atoms; 10 At least one hydrogen atom in the alkyl group and alkenyl group in L may be substituted with a substituent; 10 is a direct bond, and R c R is an aryl group having 6 to 12 carbon atoms which may have the first substituent. 10 The alkyl group having 1 to 6 carbon atoms and the alkenyl group having 1 to 6 carbon atoms are the same as those in the above R 1 The alkyl group having 1 to 6 carbon atoms and the alkenyl group having 1 to 6 carbon atoms are selected from the same options as those for the alkyl group having 1 to 6 carbon atoms and the alkenyl group having 1 to 6 carbon atoms. Alternatively, R 10 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; L is a carbonyloxy group or a carbonylamino group; R c is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms which may have the first substituent. Furthermore, L is a carbonyloxy group or a carbonylamino group, and R c is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, and R 10is 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. 10 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. The unit I is a different unit from the units AH.

[0148] Examples of the unit I include units derived from monomers such as α-methylstyrene derivatives, 2-ethylacrylic acid and ester derivatives thereof, 2-benzylacrylic acid and ester derivatives thereof, 2-propylacrylic acid and ester derivatives thereof, 2-isopropylacrylic acid and ester derivatives thereof, 2-butylacrylic acid and ester derivatives thereof, 2-sec-butylacrylic acid and ester derivatives thereof, 2-fluoromethylacrylic acid and ester derivatives thereof, 2-chloromethylacrylic acid and ester derivatives thereof, 2-bromomethylacrylic acid and ester derivatives thereof, and 2-iodomethylacrylic acid and ester derivatives thereof. Specific examples of the unit I include those derived from the monomers shown below.

[0149] [ka]

[0150] The polymer in one embodiment of the present invention may have a unit J represented by the following general formula (9).

[0151] [ka]

[0152] In the above formula (9), R 1 , L and Sp are R in the above general formula (2), 1, L, and Sp are selected from the same choices. R d is selected from the group consisting of an optionally substituted linear, branched, or cyclic alkylsilyl group having 1 to 12 carbon atoms, an optionally substituted linear, branched, or cyclic alkyloxysilyl group having 1 to 12 carbon atoms, an optionally substituted linear, branched, or cyclic alkenylsilyl group having 1 to 12 carbon atoms, and an optionally substituted linear, branched, or cyclic alkenyloxysilyl group having 1 to 12 carbon atoms. Some of the carbon atoms may be substituted with silicon atoms and oxygen atoms, thereby containing a siloxane bond in which the bonding hydrogen or carbon is replaced with oxygen. The unit J contains silicon, which can enhance the etching resistance to oxygen plasma. Furthermore, when the polymer contains a silane structure as the unit J, the unit B reacts in the presence of an acid catalyst to generate water, which hydrolyzes the unit J to form silanol, forming a siloxane bond and crosslinking, thereby improving sensitivity and substrate adhesion, which is preferable. The unit J is a different unit from the units A to I.

[0153] The unit J can be, for example, 4-trimethylsilylstyrene, 4-trimethoxysilylstyrene, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, 3-(3,5,7,9,11,13,15-heptaisobutylpentacyclic [9,5,1 3,9 ,1 5,15 ,1 7,13 ]octasiloxan-1-yl)propyl methacrylate, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 8-acryloxyoctyltrimethoxysilane, 3-(3,5,7,9,11,13,15-heptaisobutylpentacyclic[9,5,1 3,9 ,1 5,15 ,1 7,13]octasiloxane-1-yl)propyl methacrylate and the like.

[0154] 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 K having an onium salt structure other than the unit A. The unit K may be an anion X in the unit A. - is the following Y - In addition, Y - is a monovalent anion having an organic group that does not contain either a hydroxyl group or a sulfanyl group.

[0155] Y - is preferably 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, tetrafluoroborate anion, hexafluorophosphonate anion, dialkylsulfonylimide anion, trialkylsulfonate methide anion, tetrakisphenylborate anion, and hexafluoroantimonate anion. Also, Y - The anion Y may be any one selected from the group consisting of monovalent metal oxonium anions and hydrogen acid anions containing the same. - At least one hydrogen atom of the alkyl group and aryl group in Y may be substituted with a fluorine atom, and Y may have the first substituent described above (excluding a hydroxyl group). - The number of carbon atoms in the group including the substituents is preferably 1 to 6. Metal oxonium anions include NiO2 - and SbO3 - Also, VO4 3- , SeO3 2- , SeO4 2- , MoO4 2- , SnO3 2- , TeO32- , TeO4 2- , TaO3 2- and WO4 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.

[0156] The acid generated from the unit K is a strong acid (Y - CF3SO3 - When an aqueous organic solvent solution is used as a developer using a polymer having an acid-dissociable group as another unit, it is preferable that the polymer of the present invention does not contain a unit having an acid-dissociable group as another unit. The reason for this is that when the polymer of the present invention contains a unit having an acid-dissociable group as another unit, the solubility of the polymer in an aqueous developer tends to increase due to the action of the acid generated by decomposition of the unit K.

[0157] The unit K may be used as a photodegradable base (when the unit K is used as a photodegradable base, it is also referred to as "unit K2"). The anion of the unit K2 is Y - Among these, it is preferable that the anion is any one selected from the group consisting of alkyl carboxylate anions and aryl carboxylate anions. These are monovalent anions having an organic group that does not contain either a hydroxyl group or a sulfanyl group, and at least one hydrogen atom of the alkyl group of the alkyl carboxylate anion and the aryl group of the aryl carboxylate anion may be substituted with a fluorine atom. The polymer having the unit K2 has the effect of reducing the LWR, and is therefore effective when high resolution is required.

[0158] The polymer according to one embodiment of the present invention may have two or more types of the unit K in the polymer.

[0159] In one embodiment of the present invention, the polymer preferably has, in molar ratios relative to 1 unit A, 0.2 to 5 unit B, 0 to 3 unit C, 0 to 2 unit D, 0 to 2 unit E, 0 to 2 unit F, 0 to 2 unit G, 0 to 2 unit H, 0 to 2 unit I, 0 to 0.5 unit J, 0 to 4 unit K, and 0 to 2 unit K. When the polymer contains a unit A1 and at least one of a unit A2 and a unit K2 as a photodegradable base, the molar ratio of the total of the units A2 and K2 to the unit A1 is preferably 0.1 to 1.0, more preferably 0.3 to 0.6. The polymer according to one embodiment of the present invention can be obtained by polymerizing the monomer components constituting the above-mentioned units as raw materials in the above-mentioned proportions by a conventional method. Alternatively, a polymer containing a unit having an onium salt structure (referred to as a "precursor polymer") may be first synthesized, and the anion moiety of the onium salt structure in the precursor polymer may be salt-exchanged to obtain a polymer containing a unit A having the desired anion. In one embodiment of the present invention, the molecular weight of the polymer is not particularly limited.

[0160] <2> Resist composition A resist composition according to one embodiment of the present invention is characterized by containing the above polymer. In addition to the above polymer, the composition may optionally contain components such as polysubstituted alcohol compounds, organometallic compounds, and organometallic complexes. Each component will be described below. The blend amount of the above polymer in the resist composition is preferably 70 to 100 mass % of the total solid content. (Polysubstituted alcohol compounds) The resist composition of one embodiment of the present invention may contain only the above-mentioned polymer, but may also contain, in addition to the above-mentioned polymer, other components such as compounds having two or more hydroxyl groups in the molecule, such as ethylene glycol, triethylene glycol, erythritol, arabitol, 1,4-benzenedimethanol, and 2,3,5,6-tetrafluoro-1,4-benzenedimethanol. By including these in the resist composition, the efficiency of the crosslinking reaction can be improved, and sensitivity to particle beams or electromagnetic waves can be increased.

[0161] (Organometallic Compounds and Organometallic Complexes) The resist composition according to one embodiment of the present invention preferably further contains either an organometallic compound or an organometallic complex. The metal is preferably at least one selected from the group consisting of Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, Rn, and Ra, because this allows sensitization of the unit A and the unit B.

[0162] Examples of the organometallic compound include tetraaryltin, tetraalkyltin, and bis(alkylphosphine)platinum. Examples of organometallic complexes include hafnium(IV) acrylate, zirconium(IV) acrylate, bismuth(III) acrylate, bismuth(III) acetate, and tin(II) oxalate. The amount of the organometallic compound or organometallic complex blended in the resist composition is preferably 0 to 0.5 molar equivalents relative to the unit A.

[0163] (Other ingredients) In any embodiment, the resist composition of one aspect of the present invention may contain other components within the range that does not impair the effects of the present invention. The components that can be added include at least one selected from known additives such as fluorine-containing water-repellent polymers, acid diffusion controllers, organic carboxylic acids, surfactants, fillers, pigments, antistatic agents, flame retardants, light stabilizers, antioxidants, ion scavengers, and organic solvents. The fluorine-containing water-repellent polymer may be one that is commonly used in immersion lithography processes, and preferably has a fluorine atom content greater than that of the above-mentioned polymer. By doing so, when a resist film is formed using the resist composition, the water-repellent properties of the fluorine-containing water-repellent polymer can cause the fluorine-containing water-repellent polymer to be unevenly distributed on the surface of the resist film.

[0164] The acid diffusion controller controls the diffusion of the acid generated from the photoacid generator within the resist film, thereby suppressing undesirable chemical reactions in unexposed regions. As a result, the storage stability of the resulting resist composition is further improved, the resolution as a resist is further improved, and changes in the line width of the resist pattern due to variations in the exposure time between exposure and development can be suppressed, resulting in a resist composition with excellent process stability.

[0165] Examples of the acid diffusion controller include compounds having one nitrogen atom, two nitrogen atoms, or three nitrogen atoms in the same molecule, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, etc. The acid diffusion controller may be used as a monomer constituting a unit of the polymer and may be contained in the polymer. Alternatively, a photodegradable base that is photosensitive to light upon exposure to generate a weak acid can be used as the acid diffusion controller. Examples of the photodegradable base include onium salt compounds and iodonium salt compounds that decompose upon exposure to light and lose their acid diffusion control properties.

[0166] Specific examples of the acid diffusion controller include compounds described in Japanese Patent No. 3577743, JP-A Nos. 2001-215689, 2001-166476, 2008-102383, 2010-243773, 2011-37835, and 2012-173505.

[0167] The content of the acid diffusion controller is preferably 0.01 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and even more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the polymer component. The surfactant is preferably used to improve the coating property. Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene polyoxypropylene block copolymers, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters, fluorine-containing surfactants, and organosiloxane polymers. The content of the surfactant is preferably 0.0001 to 12 parts by mass, and more preferably 0.0005 to 1% by mass, relative to 100 parts by mass of the polymer component.

[0168] Preferred examples of the organic solvent include ethylene glycol monoethyl ether acetate, cyclohexanone, 2-heptanone, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl β-methoxyisobutyrate, ethyl butyrate, propyl butyrate, methyl isobutyl ketone, ethyl acetate, isoamyl acetate, ethyl lactate, toluene, xylene, cyclohexyl acetate, diacetone alcohol, N-methylpyrrolidone, N,N-dimethylformamide, γ-butyrolactone, N,N-dimethylacetamide, propylene carbonate, and ethylene carbonate. These organic solvents may be used alone or in combination.

[0169] <3> Method for preparing a resist composition There are no particular restrictions on the method for preparing the resist composition of one embodiment of the present invention, and it can be prepared by known methods such as mixing, dissolving or kneading the above-mentioned polymer and other optional components. The polymer can be synthesized by appropriately polymerizing the monomers constituting the units A and B and, if necessary, the monomers constituting other units, by a conventional method. However, the method for producing the polymer according to the present invention is not limited to this.

[0170] The resist composition components are preferably dissolved in the organic solvent to a solids concentration of 1 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 3 to 20% by mass. By adjusting the solids concentration within this range, the above-mentioned film thickness can be achieved.

[0171] The composition of one embodiment of the present invention can be obtained by mixing the components of the composition described above, and the mixing method is not particularly limited.

[0172] <4> Manufacturing method of components One aspect of the present invention is a method for producing a member, the method comprising: 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 in a pattern using particle beams or electromagnetic waves; and a pattern formation step of developing the exposed resist film to obtain a photoresist pattern. Examples of the member include a device and a mask.

[0173] 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 type and blending ratio of each component in the photocurable composition, the thickness of the coating film, etc., but is generally 1 J / cm 2 Less than or equal to 1000μC / cm 2 It is preferable that: When the resist composition contains a sensitizing unit (unit C) in the polymer or a sensitizing compound, it is also preferable to carry out a second exposure with ultraviolet light or the like after irradiation with particle beams or electromagnetic waves.

[0174] Another aspect of the present invention is a method for manufacturing a device, comprising, in the photolithography process, a step of irradiating a second active energy ray having lower energy than the particle beam or electromagnetic wave after exposure to the particle beam or electromagnetic wave.

[0175] The first and second active energy rays are not particularly limited as long as the onium salt of the polymer according to some embodiments of the present invention does not significantly absorb the second active energy ray, but it is preferable that the wavelength of the first active energy ray is shorter than that of the second active energy ray, or that the energy of the photon or particle beam is higher. Examples of each active energy ray are shown below, but are not limited thereto as long as the wavelength of the first active energy ray is shorter than that of the second active energy ray, or the energy of the photon or particle beam is higher. The first active energy ray is not particularly limited as long as it can generate active species such as acid in the resist film after irradiation of the resist film. Preferred examples include KrF excimer laser light, ArF excimer laser light, electron beams, and extreme ultraviolet (EUV) rays.

[0176] The second active energy ray may be any light capable of activating a ketone derivative produced by deprotection of the (thio)acetal moiety of the onium salt according to some embodiments of the polymer of the present invention with an acid generated in the resist film after irradiation with the first active energy ray, thereby generating an active species such as an acid. For example, this means KrF excimer laser light, UV, visible light, etc., and it is particularly preferable to use UV light in the range of 365 nm (i-line) to 436 nm (g-line).

[0177] In one embodiment of the device manufacturing method of the present invention, it is preferable to include a heating step using an electric heating wire or a laser between the step of irradiating the first active energy ray and the step of irradiating the second active energy ray. This step can improve the decomposition efficiency of the onium salt of unit A, leading to further improvement in sensitivity. The heating step can be performed using a hot plate or the like, and in the device manufacturing method, this step corresponds to pre-baking.

[0178] Preferably, the method for manufacturing a member according to one embodiment of the present invention further includes the steps of applying a reversal pattern composition so as to cover at least the recesses of the photoresist pattern, etching the resulting coating to expose the surface of the photoresist pattern, and removing the resist film from the exposed surface portion of the resist pattern to obtain a reversal pattern. As the composition for forming a reverse pattern, a known composition for forming a reverse pattern can be used, for example, a composition containing a siloxane polymer described in International Publication WO2015 / 025665, etc.

[0179] Another aspect of the present invention is 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 to particle beams or electromagnetic waves; and a pattern forming step of developing the exposed resist film to obtain a photoresist pattern.

[0180] Another aspect of the present invention is 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 to particle beams or electromagnetic waves; a pattern formation step of developing the exposed resist film to obtain a photoresist pattern; a step of applying a reversal pattern composition so as to cover at least the recesses of the photoresist pattern, and etching the resulting coating to expose the surface of the photoresist pattern; and removing the resist film from the exposed surface portion of the resist pattern to obtain a reverse pattern. Apart from using the above resist composition, a normal method for forming a reverse pattern may be used. Preferred examples of the substrate include inorganic substrates such as Si, SiO, SiN, SiON, TiN, WSi, and BPSG (Boron Phosphorus Silicon Glass); and coated inorganic substrates such as SOG (Spin on Glass) to which an organic anti-reflective film or the like is applied, in the case of a device manufacturing method. In the case of a method for manufacturing a mask, the substrate is preferably an inorganic substrate such as Cr, CrO, CrON, MoSi2, or SiO2, and more preferably has an EUV absorbing layer such as TaO. The substrate for manufacturing a mask may have the same configuration as the substrate used for a normal mask. For example, in the case of a transmission mask, it is preferably transparent to the transmitted light of the target, and in the case of a reflective mask, it is preferably highly reflective to the target light (electromagnetic waves such as EUV).

[0181] For development in the pattern forming step, a conventional developer can be used, and examples of the developer include an alkaline developer, a neutral developer, and an organic solvent developer. In addition, as a developer other than the above, a water-soluble developer containing a water-soluble organic solvent is also preferably used. Examples of the water-soluble organic solvent include organic compounds having one or more carbon atoms that can be mixed with water at any ratio, such as methanol, ethanol, isopropyl alcohol, diacetone alcohol, ethylene glycol, ethylene glycol monomethyl ether, propylene glycol, propylene glycol monomethyl ether, triethylene glycol, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, diglyme, triglyme, acetonitrile, acetone, N,N-dimethylformamide, dimethyl sulfoxide, formic acid, acetic acid, and propionic acid.

[0182] The water-soluble developer may be an aqueous solution containing one or more water-soluble organic solvents, and may further contain a non-water-soluble organic solvent. Examples of the non-water-soluble organic solvent include water-immiscible alcohols, water-immiscible ethers, water-immiscible nitriles, water-immiscible ketones, water-immiscible esters such as ethyl acetate, and organic halogen compounds such as methylene chloride.

[0183] The substrate is not particularly limited and may be any known substrate, such as a substrate made of metal such as silicon, silicon nitride, titanium, tantalum, palladium, copper, chromium, or aluminum; a glass substrate; or the like. In one embodiment of the present invention, preferred examples of active energy rays used for exposure in a photolithography process used to obtain an interlayer insulating film or the like for producing an LSI include UV, KrF excimer laser light, ArF excimer laser light, electron beams, and extreme ultraviolet (EUV) light.

[0184] The irradiation dose of the first actinic energy ray varies depending on the type and blending ratio of each component in the photocurable composition, the film thickness of the coating film, etc., but is 1 J / cm 2 or less than 1000μC / cm 2 It is preferable that: In one embodiment of the present invention, the resist film formed from the resist composition preferably has a thickness of 10 to 200 nm. The resist composition is applied to a substrate by a suitable application method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor coating, and then prebaked at 60 to 150°C for 1 to 20 minutes, preferably 80 to 120°C for 1 to 10 minutes, to form a thin film. The thickness of this applied film is 5 to 200 nm, and preferably 10 to 100 nm. [Example]

[0185] 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.

[0186] <Synthesis of Compound A1, which constitutes Unit A> (Synthesis Example 1) Synthesis of dibenzothiophene-9-oxide

[0187] [ka]

[0188] 7.0 g of dibenzothiophene is dissolved in 21.0 g of formic acid and the temperature is brought to 35°C. 4.1 g of 35% by mass hydrogen peroxide is added dropwise and stirred at 25°C for 5 hours. After cooling, the reaction solution is added dropwise to 50 g of pure water to precipitate a solid. The precipitated solid is filtered, washed twice with 20 g of pure water, and then recrystallized using acetone. This is filtered and dried to obtain 7.6 g of dibenzothiophene-9-oxide.

[0189] (Synthesis Example 2) Synthesis of 9-(4-hydroxyphenyl)dibenzothiophenium iodide

[0190] [ka]

[0191] 4.0 g of dibenzothiophene-9-oxide obtained in Synthesis Example 1 above and 2.8 g of phenol were dissolved in 16 g of methanesulfonic acid and the temperature was adjusted to 25°C. 1.5 g of diphosphorus pentoxide was added and the mixture was stirred at room temperature for 15 hours. 60 g of purified water was then added and the mixture was stirred for an additional 5 minutes, followed by washing twice with 20 g of ethyl acetate. The mixture was separated, and 3.6 g of potassium iodide and 30 g of methylene chloride were added to the resulting aqueous layer and the mixture was stirred at room temperature for 2 hours. The mixture was then separated, and the resulting organic layer was washed four times with 40 g of purified water. The recovered organic layer was concentrated and added dropwise to 100 g of diisopropyl ether to precipitate a solid. The precipitated solid was filtered and dried to obtain 6.6 g of 9-(4-hydroxyphenyl)dibenzothiophenium iodide.

[0192] (Synthesis Example 3) Synthesis of 9-(4-hydroxyphenyl)dibenzothiophenium methyl sulfate

[0193] [ka]

[0194] 6.0 g of 9-(4-hydroxyphenyl)dibenzothiophenium iodide obtained in Synthesis Example 2 above and 2.3 g of dimethyl sulfate are dissolved in 15 g of methanol, the temperature is raised to 25°C, and the mixture is stirred at room temperature for 4 hours. 45 g of ethyl acetate is then added to precipitate a solid. The precipitated solid is filtered and dried to obtain 4.9 g of 9-(4-hydroxyphenyl)dibenzothiophenium methyl sulfate.

[0195] (Synthesis Example 4) Synthesis of 9-(4-methacryloxyphenyl)dibenzothiophenium methyl sulfate (compound a1)

[0196] [ka]

[0197] 4.0 g of 9-(4-hydroxyphenyl)dibenzothiophenium methyl sulfate obtained in Synthesis Example 3 above and 1.9 g of methacrylic acid chloride were dissolved in 25 g of methylene chloride and the temperature was adjusted 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 recovered organic layer was concentrated and added dropwise to 60 g of diisopropyl ether to precipitate a solid. The precipitated solid was filtered and dried to obtain 3.0 g of 9-(4-methacryloxyphenyl)dibenzothiophenium methyl sulfate (compound a1).

[0198] (Synthesis Example 5) Synthesis of 9-(4-methacryloxyphenyl)dibenzothiophenium-1,1-difluoro-2-hydroxyethylsulfonate (Compound A1)

[0199] [ka]

[0200] 4.0 g of 9-(4-methacryloxyphenyl)dibenzothiophenium methyl sulfate obtained in Synthesis Example 4 above and 3.2 g of sodium 1,1-difluoro-2-hydroxyethanesulfonate were added to 25 g of methylene chloride and 20 g of pure water and stirred at 25°C for 1 hour. After stirring, the mixture was separated, and 1.6 g of sodium 1,1-difluoro-2-hydroxysulfonate and 20 g of pure water were added again and stirred at 25°C for 30 minutes. After stirring, the mixture was separated and the recovered organic layer was concentrated. The solvent was removed from the resulting organic layer, and the resulting solution was purified by column chromatography (methylene chloride / methanol = 90 / 10 (volume ratio)) to obtain 3.0 g of 9-(4-methacryloxyphenyl)dibenzothiophenium-1,1-difluoro-2-hydroxyethylsulfonate (Compound A1).

[0201] <Synthesis of Compound A2, which constitutes Unit A> (Synthesis Example 6) Synthesis of (4-hydroxy)phenyldiphenylsulfonium iodide

[0202] [ka]

[0203] The same procedure as in Synthesis Example 2 above is carried out except that diphenyl sulfoxide is used instead of dibenzothiophene-9-oxide, to obtain 5.9 g of (4-hydroxy)phenyldiphenylsulfonium iodide.

[0204] (Synthesis Example 7) Synthesis of (4-methacryloxy)phenyldiphenylsulfonium trifluoromethanesulfonate (Compound a2)

[0205] [ka]

[0206] The same procedure as in Synthesis Example 4 above was carried out, except that (4-hydroxy)phenyldiphenylsulfonium-methylsulfate was used instead of 9-(4-hydroxyphenyl)dibenzothiophenium-methylsulfate, and silica gel column chromatography (methylene chloride / methanol = 9 / 1) was used instead of diisopropyl ether to precipitate the solid, to obtain 3.8 g of 9-(4-methacryloxyphenyl)dibenzothiophenium-methylsulfate (compound a2).

[0207] (Synthesis Example 8) Synthesis of 9-(4-methacryloxyphenyl)diphenylsulfonium-1,1-difluoro-2-hydroxyethylsulfonate (Compound A2)

[0208] [ka]

[0209] By carrying out the same procedure as in Synthesis Example 5 above, except for using (4-methacryloxy)phenyldiphenylsulfonium-methylsulfate instead of 9-(4-methacryloxyphenyl)dibenzothiophenium-methylsulfate, 3.0 g of 9-(4-methacryloxyphenyl)diphenylsulfonium-1,1,difluoro-2-hydroxyethylsulfonate (Compound A2) is obtained.

[0210] <Synthesis of Compound A3, which constitutes Unit A> (Synthesis Example 9) Synthesis of 9-(4-methacryloxyphenyl)diphenylsulfonium-1,1,2-trifluoro-3-hydroxypropylsulfonate (Compound A3)

[0211] [ka]

[0212] The same procedure as in Synthesis Example 5 above was carried out, except that (4-methacryloxy)phenyldiphenylsulfonium-methylsulfate was used instead of 9-(4-methacryloxyphenyl)dibenzothiophenium-methylsulfate, and sodium 1,1,2-trifluoro-2-hydroxypropanesulfonate was used instead of sodium 1,1-difluoro-2-hydroxyethanesulfonate, to obtain 3.0 g of 9-(4-methacryloxyphenyl)diphenylsulfonium-1,1,2-trifluoro-3-hydroxypropylsulfonate (Compound A3).

[0213] <Synthesis of Compound A4, which constitutes Unit A> (Synthesis Example 10) Synthesis of 9-(4-methacryloxyphenyl)diphenylsulfonium-3-allyloxy-2-hydroxypropylsulfonate (Compound A4)

[0214] [ka]

[0215] The same procedure as in Synthesis Example 5 above was carried out, except that (4-methacryloxy)phenyldiphenylsulfonium-methylsulfate was used instead of 9-(4-methacryloxyphenyl)dibenzothiophenium-methylsulfate, and sodium 3-allyloxy-2-hydroxypropanesulfonate was used instead of sodium 1,1-difluoro-2-hydroxyethanesulfonate, to obtain 3.0 g of 9-(4-methacryloxyphenyl)diphenylsulfonium 3-allyloxy-2-hydroxypropylsulfonate (Compound A4).

[0216] <Synthesis of Compound A5, which constitutes Unit A> (Synthesis Example 11) Synthesis of 9-(4-methacryloxyphenyl)diphenylsulfonium-3-mercaptopropylsulfonate (Compound A5)

[0217] [ka]

[0218] The same procedure as in Synthesis Example 5 above was carried out, except that (4-methacryloxy)phenyldiphenylsulfonium-methylsulfate was used instead of 9-(4-methacryloxyphenyl)dibenzothiophenium-methylsulfate, and sodium 3-mercaptopropanesulfonate was used instead of sodium 1,1-difluoro-2-hydroxyethanesulfonate, to obtain 3.0 g of 9-(4-methacryloxyphenyl)diphenylsulfonium-3-mercaptopropylsulfonate (Compound A5).

[0219] <Synthesis of Compound A6, which constitutes Unit A> (Synthesis Example 12) Synthesis of 5-(4-hydroxynaphthyl)tetramethylenesulfonium p-toluenesulfonate

[0220] [ka]

[0221] The same procedure as in Synthesis Example 2 above is carried out, except that tetramethylene sulfoxide is used instead of dibenzothiophene-9-oxide, 1-naphthol is used instead of phenol, and sodium p-toluenesulfonate is used instead of potassium iodide, to obtain 3.5 g of 5-(4-hydroxynaphthyl)tetramethylenesulfonium p-toluenesulfonate.

[0222] (Synthesis Example 13) Synthesis of 5-(4-methacryloxynaphthyl)tetramethylenesulfonium p-toluenesulfonate

[0223] [ka]

[0224] The same procedure as in Synthesis Example 4 was carried out except that 5-(4-hydroxynaphthyl)tetramethylenesulfonium trifluoromethanesulfonate was used instead of 9-(4-hydroxyphenyl)dibenzothiophenium methylsulfate, to obtain 5.1 g of (5-(4-methacryloxynaphthyl)tetramethylenesulfonium p-toluenesulfonate.

[0225] (Synthesis Example 14) Synthesis of 5-(4-methacryloxynaphthyl)tetramethylenesulfonium-1,1-difluoro-2-hydroxyethylsulfonate (Compound A6)

[0226] [ka]

[0227] The same procedure as in Synthesis Example 5 above is carried out, except that (4-methacryloxy)phenyldiphenylsulfonium-methylsulfate is used instead of 9-(4-methacryloxyphenyl)dibenzothiophenium-methylsulfate, to obtain 3.0 g of 9-(4-methacryloxyphenyl)diphenylsulfonium-1,1-difluoro-2-hydroxyethylsulfonate (Compound A6).

[0228] <Synthesis of Compound A7, which constitutes Unit A> (Synthesis Example 15) Synthesis of 2-(4-methoxybenzoyl)dibenzothiophene

[0229] [ka]

[0230] Add 5.0 g of aluminum chloride to 50 g of methylene chloride and bring the temperature to 0°C. Add 5 g of dibenzothiophene, then dissolve 4.6 g of 4-methoxybenzoyl chloride in 9.2 g of methylene chloride and add dropwise over 30 minutes. After the dropwise addition, stir at 25°C for 1 hour, add 60 g of purified water, stir for an additional 5 minutes, and then wash twice with 20 g of toluene. The resulting organic layer is distilled off. The resulting residue is purified by recrystallization using 30 g of acetone to obtain 6.1 g of 2-(4-methoxybenzoyl)dibenzothiophene.

[0231] (Synthesis Example 16) Synthesis of 2-(4-methoxybenzoyl)dibenzothiophene-5-oxide

[0232] [ka]

[0233] 6.0 g of 2-(4-methoxybenzoyl)dibenzothiophene obtained in Synthesis Example 15 above was dissolved in 30 g of formic acid, and 3.5 g of 35% by mass hydrogen peroxide solution was added dropwise to the solution under ice cooling. The mixture was then warmed to room temperature and stirred for 5 hours. After stirring, 80 g of pure water was added dropwise to the reaction solution to precipitate a solid. The precipitated solid was filtered, washed three times with 10 g of pure water, and then dried to obtain crude crystals. The crude crystals were recrystallized using 100 g of acetone and 200 g of ethanol to obtain 4.3 g of 2-(4-methoxybenzoyl)dibenzothiophene-5-oxide.

[0234] (Synthesis Example 17) Synthesis of 2-[dimethoxy-(4-methoxyphenyl)methyldibenzothiophene-5-oxide]

[0235] [ka]

[0236] 5.0 g of 2-(4-methoxybenzoyl)dibenzothiophene-5-oxide obtained in Synthesis Example 16 was added to 20 g of methanol, and 5.0 g of trimethyl orthoformate and 20 mg of concentrated sulfuric acid were added to the mixture 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 the mixture was 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 4.6 g of 2-[dimethoxy-(4-methoxyphenyl)methyldibenzothiophene-5-oxide.

[0237] (Synthesis Example 18) Synthesis of 4-vinylphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium-1,1-difluoro-2-hydroxyethanesulfonate (Compound A7)

[0238] [ka]

[0239] To a solution of 4.0 g of 2-[dimethoxy-(4-methoxyphenyl)methyldibenzothiophene-5-oxide obtained in Synthesis Example 17 above, 1.1 g of trimethylsilyl chloride, and 1.8 g of triethylamine dissolved in 15.5 g of methylene chloride, 15 ml of a 1.0 mol / L THF solution of 4-vinylphenylmagnesium bromide was added dropwise at 10°C or below, followed by stirring at 25°C for 1 hour. After stirring, 30 g of a 10% by mass aqueous ammonium chloride solution was added at 5°C or below and stirred for an additional 10 minutes. After that, 40 g of methylene chloride and 2.7 g of sodium 1,1-difluoro-2-hydroxyethanesulfonate were added and stirred at 25°C for approximately 2 hours. The mixture was separated and washed three times with water, and then the methylene chloride was distilled off to obtain crude crystals. The crude crystals are purified by silica gel column chromatography (methylene chloride / methanol=90 / 10 (volume ratio)) to obtain 2.6 g of 4-vinylphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium-1,1-difluoro-2-hydroxyethanesulfonate (compound A7).

[0240] <Synthesis of Compound A8, which constitutes Unit A> (Synthesis Example 19) Synthesis of 4-hydroxyphenyl-2-[(4-methoxy)benzoyl]dibenzothiophenium iodide

[0241] [ka] By carrying out the same procedure as in Synthesis Example 2 above, except that 2-(4-methoxybenzoyl)dibenzothiophene-5-oxide is used instead of dibenzothiophene-9-oxide, 3.0 g of 4-hydroxyphenyl-2-[(4-methoxy)benzoyl]dibenzothiophenium-iodide is obtained.

[0242] (Synthesis Example 20) Synthesis of 4-hydroxyphenyl-2-[(4-methoxy)benzoyl]dibenzothiophenium methyl sulfate

[0243] [ka]

[0244] The same procedure as in Synthesis Example 3 above is carried out, except that 4-hydroxyphenyl-2-[(4-methoxy)benzoyl]dibenzothiophenium-iodide obtained in Synthesis Example 19 above is used instead of 9-(4-hydroxyphenyl)dibenzothiophenium-iodide, to obtain 3.0 g of 4-hydroxyphenyl-2-[(4-methoxy)benzoyl]dibenzothiophenium-methylsulfate.

[0245] (Synthesis Example 21) Synthesis of 4-hydroxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate

[0246] [ka]

[0247] The same procedure as in Synthesis Example 17 was carried out except that 4-hydroxyphenyl-2-[(4-methoxy)benzoyl]dibenzothiophenium-methylsulfate obtained in Synthesis Example 20 was used instead of 2-(4-methoxybenzoyl)dibenzothiophene-5-oxide, to obtain 3.0 g of 4-hydroxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium-methylsulfate.

[0248] (Synthesis Example 22) Synthesis of 4-methacryloxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium methyl sulfate

[0249] [ka]

[0250] The same procedure as in Synthesis Example 4 above is carried out, except that 4-hydroxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium-methylsulfate obtained in Synthesis Example 21 above is used instead of 9-(4-methacryloxyphenyl)dibenzothiophenium-methylsulfate, to obtain 3.0 g of 4-methacryloxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium-methylsulfate.

[0251] (Synthesis Example 23) Synthesis of 4-methacryloxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium-1,1-difluoro-2-hydroxyethanesulfonate (Compound A8)

[0252] [ka]

[0253] The same procedure as in Synthesis Example 5 above is carried out, except that 4-methacryloxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium-methylsulfate obtained in Synthesis Example 22 above is used instead of 9-(4-methacryloxyphenyl)dibenzothiophenium-methylsulfate, to obtain 3.0 g of 4-methacryloxyphenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium-1,1-difluoro-2-hydroxyethanesulfonate (Compound A8).

[0254] <Synthesis of Compound A9, which constitutes Unit A> (Synthesis Example 24) Synthesis of 2-[methoxyphenyl-[1,3]dioxepan-2-yl]dibenzothiophene-5-oxide

[0255] [ka]

[0256] The same procedure as in Synthesis Example 17 was carried out except that 1,4-butanediol was used instead of methanol, to obtain 3.0 g of 2-[methoxyphenyl-[1,3]dioxepan-2-yl]dibenzothiophene-5-oxide.

[0257] (Synthesis Example 25) Synthesis of 4-vinylphenyl-2-[methoxyphenyl-[1,3]dioxepan-2-yl]dibenzothiophenium-1,1-difluoro-2-hydroxyethanesulfonate (Compound A9)

[0258] [ka]

[0259] The same procedure as in Synthesis Example 18 above is carried out, except that 2-[methoxyphenyl-[1,3]dioxepan-2-yl]dibenzothiophene-5-oxide obtained in Synthesis Example 24 above is used instead of 2-[dimethoxy-(4-methoxyphenyl)methyldibenzothiophene-5-oxide methanol, to obtain 3.0 g of 4-vinylphenyl-2-[methoxyphenyl-[1,3]dioxepan-2-yl]dibenzothiophenium-1,1-difluoro-2-hydroxyethanesulfonate (Compound A9).

[0260] <Synthesis of Compound A10, which constitutes Unit A> (Synthesis Example 26) Synthesis of phenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium bromide

[0261] [ka]

[0262] To a solution of 4.0 g of 2-[dimethoxy-(4-methoxyphenyl)methyldibenzothiophene-5-oxide obtained in Synthesis Example 17 above, 1.1 g of trimethylsilyl chloride, and 1.8 g of triethylamine dissolved in 15.5 g of methylene chloride, 15 ml of a 1.0 mol / L THF solution of 4-vinylphenylmagnesium bromide was added dropwise at 10°C or below, followed by stirring at 25°C for 1 hour. After stirring, 30 g of a 10% by mass aqueous ammonium chloride solution was added at 5°C or below, and the mixture was stirred for an additional 10 minutes. 40 g of methylene chloride was added and the mixture was stirred at 25°C for approximately 2 hours. The mixture was separated and washed three times with water, after which the methylene chloride was distilled off to obtain crude crystals. The crude crystals were purified by silica gel column chromatography (methylene chloride / methanol = 90 / 10 (volume ratio)) to obtain 3.0 g of phenyl-2-[dimethoxy-(4-methoxyphenyl)methyl]dibenzothiophenium bromide.

[0263] (Synthesis Example 27) Synthesis of phenyl-2-(4-hydroxybenzoyl)dibenzothiophenium bromide

[0264] [ka]

[0265] 3.0 g of phenyl-2-[dimethoxy-(4-methoxyphenyl)]methyldibenzothiophenium bromide obtained in Synthesis Example 26 above was added to 30 ml of acetic acid and heated to 110°C. 2.2 g of 48% aqueous hydrobromic acid was then added dropwise and stirred for 18 hours. After cooling to 25°C, 60 ml of purified water and 40 g of methylene chloride were added and stirred. The mixture was separated and washed three times with water, after which the methylene chloride was distilled off to obtain crude crystals. The crude crystals were purified by silica gel column chromatography (methylene chloride / methanol = 80 / 20 (volume ratio)) to obtain 1.4 g of phenyl-2-(4-hydroxybenzoyl)dibenzothiophenium bromide.

[0266] (Synthesis Example 28) Synthesis of phenyl-2-[dimethoxy-(4-hydroxyphenyl)]methyldibenzothiophenium bromide

[0267] [ka]

[0268] The same procedure as in Synthesis Example 17 is carried out except that phenyl-2-(4-hydroxybenzoyl)dibenzothiophenium bromide obtained in Synthesis Example 27 is used instead of 2-(4-methoxybenzoyl)dibenzothiophene-5-oxide, to obtain 1.5 g of phenyl-2-[dimethoxy-(4-hydroxyphenyl)]methyldibenzothiophenium bromide.

[0269] (Synthesis Example 29) Synthesis of phenyl-2-{dimethoxy-[4-(3-methacryloxy)propyloxyphenyl]methyl}dibenzothiophenium-1,1-difluoro-2-hydroxyethanesulfonate (Compound A10)

[0270] [ka]

[0271] 1.5 g of phenyl-2-[dimethoxy-(4-hydroxyphenyl)]methyldibenzothiophenium bromide obtained in Synthesis Example 28 above and 1.10 g of 3-trifluoromethanesulfonylpropane methacrylate were dissolved in 10 ml of acetonitrile, followed by addition of 2.1 g of potassium carbonate and stirring at 70°C for 3 hours. Subsequently, 30 ml of methylene chloride, 15 ml of purified water, and 1.3 g of sodium 1,1-difluoro-2-hydroxyethanesulfonate were added and stirred. The mixture was separated and washed three times with water, after which the methylene chloride was distilled off to obtain crude crystals. The crude crystals were purified by silica gel column chromatography (methylene chloride / methanol = 80 / 20 (volume ratio)) to obtain 1.0 g of phenyl-2-{dimethoxy-[4-(1-ethoxyethyl)oxyphenyl]methyl}dibenzothiophenium nonafluorobutanesulfonate (Compound A10).

[0272] <Synthesis of Compound B1, which constitutes Unit B> (Synthesis Example 30) Synthesis of 2,4-dimethoxy-2'-hydroxybenzohydrol

[0273] [ka]

[0274] 6.0 g of 2,4-dimethoxy-4'-hydroxybenzophenone was dissolved in 32 g of THF, 2.2 g of lithium aluminum hydride was added, and the mixture was stirred at room temperature for 3 hours. 6 g of purified water was then added while checking for hydrogen generation, and the mixture was stirred for an additional 10 minutes. A 5% by mass aqueous solution of sodium oxalate was added, and the mixture was stirred for 10 minutes. 30 g of ethyl acetate was then added and the mixture was separated. The mixture was washed three times with 10 g of water, and the collected organic layer was concentrated to obtain 5.9 g of 2,4-dimethoxy-2'-hydroxybenzohydrol.

[0275] (Synthesis Example 31) Synthesis of 2,4-dimethoxy-2'-methacryloxyhydroxybenzohydrol (Compound B1)

[0276] [ka]

[0277] 4.0 g of 2,4-dimethoxy-2'-hydroxybenzohydrol obtained in Synthesis Example 30 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 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 recovered organic layer was concentrated. The solvent was removed by distillation, and the resulting organic layer was purified by column chromatography (ethyl acetate / hexane = 15 / 85 (volume ratio)) to obtain 2.6 g of 2,4-dimethoxy-2'-methacryloxyhydroxybenzohydrol (Compound B1).

[0278] <Synthesis of Compound B2, which constitutes Unit B> (Synthesis Example 32) Synthesis of 2-hydroxybenzohydrol

[0279] [ka]

[0280] 3.5 g of 2-hydroxybenzohydrol is obtained by carrying out the same procedure as in Synthesis Example 30 above, except that 2-hydroxybenzophenone is used instead of 2,4-dimethoxy-4'-hydroxybenzophenone.

[0281] (Synthesis Example 33) Synthesis of 2-methacryloxyhydroxybenzohydrol (Compound B2)

[0282] [ka]

[0283] The same procedure as in Synthesis Example 31 above was carried out, except that 2-hydroxybenzohydrol obtained in Synthesis Example 32 was used instead of 2,4-dimethoxy-2'-hydroxybenzohydrol, and the residue obtained by concentration was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)), to obtain 3.5 g of 2-methacryloxyhydroxybenzohydrol (Compound B2).

[0284] <Synthesis of Compound B3, which constitutes Unit B> (Synthesis Example 34) Synthesis of 1-(4-hydroxyphenyl)ethanol

[0285] [ka]

[0286] 2.7 g of 1-(4-hydroxyphenyl)ethanol is obtained by carrying out the same procedure as in Synthesis Example 30 above, except that 4-hydroxyacetophenone is used instead of 2,4-dimethoxy-4'-hydroxybenzophenone.

[0287] (Synthesis Example 35) Synthesis of 1-(4-methacryloxyphenyl)ethanol (Compound B3)

[0288] [ka]

[0289] The same procedure as in Synthesis Example 31 was carried out, except that 2-hydroxybenzhydrol obtained in Synthesis Example 34 was used instead of 2,4-dimethoxy-2'-hydroxybenzhydrol, and the residue obtained by concentration was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)), to obtain 3.5 g of 2-methacryloxyhydroxybenzhydrol (Compound B3).

[0290] <Synthesis of Compound B4, which constitutes Unit B> (Synthesis Example 36) Synthesis of 2,4-dimethoxy-4'-(2-vinyloxy)ethoxybenzophenone

[0291] [ka]

[0292] 4.0 g of 2,4-dimethoxy-4'-hydroxybenzophenone, 4.8 g of 2-chloroethyl vinyl ether, and 6.4 g of potassium carbonate were dissolved in 24 g of dimethylformamide. The mixture was stirred at 110°C for 15 hours. The mixture was then cooled to 25°C, 60 g of water was added, and the mixture was further stirred. The mixture was then extracted with 24 g of toluene, washed three times with 10 g of water, and the collected organic layer was concentrated. The solvent was removed from the resulting organic layer, and the residue was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)) to obtain 5.4 g of 2,4-dimethoxy-4'-(2-vinyloxy)ethoxybenzophenone.

[0293] (Synthesis Example 37) Synthesis of 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzophenone

[0294] [ka]

[0295] 5.4 g of 2,4-dimethoxy-4'-(2-vinyloxy)ethoxybenzophenone obtained in Synthesis Example 36, 0.42 g of pyridinium-p-toluenesulfonic acid, and 4.2 g of pure water were dissolved in 36 g of acetone. The mixture was stirred at 35°C for 12 hours. After adding a 3% by mass aqueous solution of sodium carbonate, the mixture was further stirred and extracted with 42 g of ethyl acetate. The organic layer was washed three times with 10 g of water and then concentrated to obtain 4.3 g of 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzophenone.

[0296] (Synthesis Example 38) Synthesis of 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzohydrol

[0297] [ka]

[0298] 2,4-Dimethoxy-4'-(2-hydroxy)ethoxybenzohydrol is obtained by the same procedure as in Synthesis Example 30 above, except that 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzophenone obtained in Synthesis Example 37 is used instead of 2,4-dimethoxy-2'-hydroxybenzhydrol.

[0299] (Synthesis Example 39) Synthesis of 2,4-dimethoxy-4'-(2-methacryloxy)ethoxybenzohydrol (Compound B4)

[0300] [ka]

[0301] The same procedure as in Synthesis Example 31 above is carried out, except that 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzohydrol obtained in Synthesis Example 38 is used instead of 2,4-dimethoxy-2'-hydroxybenzhydrol, and the residue obtained by concentration is purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)), to obtain 3.5 g of 2,4-dimethoxy-4'-(2-methacryloxy)ethoxybenzohydrol (Compound B4).

[0302] <Synthesis of Compound B5, which constitutes Unit B> (Synthesis Example 40) Synthesis of 1-(3-hydroxy-4-methoxyphenyl)methanol

[0303] [ka]

[0304] 2.7 g of 1-(4-hydroxyphenyl)methanol is obtained by carrying out the same procedure as in Synthesis Example 30 above, except that 3-hydroxy-4-methoxybenzaldehyde is used instead of 2,4-dimethoxy-2'-hydroxybenzhydrol.

[0305] (Synthesis Example 41) Synthesis of 1-(3-methacryloxy-4-methoxyphenyl)methanol (Compound B5)

[0306] [ka]

[0307] The same procedure as in Synthesis Example 31 was carried out except that 1-(4-hydroxyphenyl)methanol obtained in Synthesis Example 40 was used instead of 2,4-dimethoxy-2'-hydroxybenzhydrol, and the residue obtained by concentration was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)), thereby obtaining 2.1 g of 1-(3-methacryloxy-4-methoxyphenyl)methanol (Compound B5).

[0308] <Synthesis of Compound B6, which constitutes Unit B> (Synthesis Example 42) Synthesis of 4-hydroxy-4'-methoxybenzohydrol

[0309] [ka]

[0310] 3.5 g of 4-hydroxy-4'-methoxybenzohydrol is obtained by carrying out the same procedure as in Synthesis Example 30 above, except that 4-hydroxy-4'-methoxybenzophenone is used instead of 2,4-dimethoxy-4'-hydroxybenzophenone.

[0311] (Synthesis Example 43) Synthesis of 4-methacryloxy-4'-methoxybenzohydrol (Compound B6)

[0312] [ka]

[0313] The same procedure as in Synthesis Example 31 was carried out except that 4-hydroxy-4'-methoxybenzohydrol obtained in Synthesis Example 42 was used instead of 4-hydroxybenzohydrol, to obtain 3.5 g of 4-methacryloxy-4'-methoxybenzohydrol (Compound B6).

[0314] <Synthesis of Compound C1, which constitutes Unit C> Synthesis Example 44: Synthesis of 1-[4-(2-methacryloxy)ethoxyphenyl]-2-hydroxy-2-methyl-1-propanone (Compound C1)

[0315] [ka]

[0316] 4.0 g of 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one (Irgacure 2959) and 4.6 g of methacrylic anhydride were dissolved in 40 g of methylene chloride and the temperature was adjusted to 25°C. A solution of 3.0 g of triethylamine dissolved in 7 g of methylene chloride was added dropwise 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. The organic layer was washed twice with 20 g of pure water, and the recovered organic layer was concentrated. The solvent was removed by distillation, and the resulting organic layer was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)) to obtain 4.9 g of 1-[4-(2-methacryloxy)ethoxyphenyl]-2-hydroxy-2-methyl-1-propanone (compound C1).

[0317] <Synthesis of Compound C2, which constitutes Unit C> Synthesis Example 45: Synthesis of 1-(4-hydroxyphenyl)-2,2-dimethyl-1-propanone

[0318] [ka]

[0319] A flask from which moisture had been removed was charged with 2.0 g of magnesium and 10 g of THF. A solution of 10.0 g of 4-(2-ethoxy)ethoxyphenyl bromide dissolved in 50.0 g of THF was added dropwise to the flask over 1 hour at room temperature. After stirring for 1 hour at room temperature, the resulting 4-(2-ethoxy)ethoxyphenyl magnesium bromide solution was added dropwise over 30 minutes at 5°C to a flask containing 9.8 g of pivaloyl chloride and 40 g of THF (prepared separately). After stirring for 30 minutes, 150 g of 3% by weight hydrochloric acid was added and the mixture was stirred for an additional 10 minutes. The THF was then distilled off and the mixture was extracted with 150 g of ethyl acetate. The resulting organic layer was separated and washed three times with 60 g of pure water. Thereafter, the organic layer obtained by separation is evaporated and then purified by column chromatography (ethyl acetate / hexane=20 / 80 (volume ratio)) to obtain 5.8 g of 1-(4-hydroxyphenyl)-2,2-dimethyl-1-propanone.

[0320] Synthesis Example 46: Synthesis of 1-(4-methacryloxyphenyl)-2,2-dimethyl-1-propanone (Compound C2)

[0321] [ka]

[0322] 4.0 g of 1-(4-hydroxyphenyl)-2,2-dimethyl-1-propanone obtained in Synthesis Example 45 above and 4.1 g of methacrylic anhydride were dissolved in 32 g of methylene chloride and the temperature was adjusted to 25°C. A solution of 2.7 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. The organic layer was washed twice with 20 g of pure water, and the recovered organic layer was concentrated. The solvent was removed from the resulting organic layer and then purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)) to obtain 4.6 g of 1-(4-methacryloxyphenyl)-2,2-dimethyl-1-propanone (Compound C2).

[0323] <Synthesis of Compound C3, which constitutes Unit C> Synthesis Example 47: Synthesis of 1-(4-acryloxyphenyl)-2,2-dimethyl-1-propanone (Compound C3) [ka]

[0324] By carrying out the same procedure as in Synthesis Example 46 above, except that acrylic acid chloride was used instead of methacrylic acid anhydride, 5.3 g of 1-(4-acryloxyphenyl)-2,2-dimethyl-1-propanone (compound C3) was obtained.

[0325] <Synthesis of Compound C4, which constitutes Unit C> (Synthesis Example 48) Synthesis of 1-(6-hydroxynaphthalen-2-yl)-2,2-dimethyl-1-propanone

[0326] [ka]

[0327] By carrying out the same procedure as in Synthesis Example 45 above, except that 2-bromo-6-(2-ethoxy)ethoxynaphthalene is used instead of 4-(2-ethoxy)ethoxyphenyl bromide, 6.9 g of 1-(6-hydroxynaphthalen-2-yl)-2,2-dimethyl-1-propanone is obtained.

[0328] Synthesis Example 49: Synthesis of 1-(6-methacryloxynaphthalen-2-yl)-2,2-dimethyl-1-propanone (Compound C4)

[0329] [ka]

[0330] By carrying out the same procedure as in Synthesis Example 46 above, except that 1-(6-hydroxynaphthalen-2-yl)-2,2-dimethyl-1-propanone was used instead of 1-(4-hydroxyphenyl)-2,2-dimethyl-1-propanone, 5.3 g of 1-(6-methacryloxynaphthalen-2-yl)-2,2-dimethyl-1-propanone (compound C4) was obtained.

[0331] <Synthesis of Compound C5, which constitutes Unit C> (Synthesis Example 50) Synthesis of 1-[4-(2-hydroxyethoxy)phenyl]-2,2-dimethyl-1-propanone

[0332] [ka]

[0333] By carrying out the same procedure as in Synthesis Example 45 above, except that 4-(2-vinyloxy)ethoxyphenyl bromide is used instead of 4-(2-ethoxy)ethoxyphenyl bromide, 6.3 g of 1-[4-(2-hydroxyethoxy)phenyl]-2,2-dimethyl-1-propanone is obtained.

[0334] Synthesis Example 51: Synthesis of 1-[4-(2-methacryloxy)ethoxyphenyl]-2,2-dimethyl-1-propanone (Compound C5)

[0335] [ka]

[0336] By carrying out the same procedure as in Synthesis Example 46 above, except that 1-(2-hydroxyethoxyphenyl)-2,2-dimethyl-1-propanone was used instead of 1-(4-hydroxyphenyl)-2,2-dimethyl-1-propanone, 5.6 g of 1-[4-(2-methacryloxy)ethoxyphenyl]-2,2-dimethyl-1-propanone (Compound C5) was obtained.

[0337] <Synthesis of Compound C6, which constitutes Unit C> (Synthesis Example 52) Synthesis of phenylglyoxylic acid chloride

[0338] [ka]

[0339] 5.0 g of phenylglyoxylic acid was dissolved in 35 g of anisole and the temperature was raised to 50°C. 5.1 g of oxalyl chloride was added dropwise over 10 minutes and stirred at 50°C for 2 hours. The temperature was raised to 70°C and excess oxalyl chloride was distilled off, and then the anisole was distilled off under reduced pressure to concentrate the mixture, yielding 26.3 g of an anisole solution of phenylglyoxylic acid chloride.

[0340] (Synthesis Example 53) Synthesis of 1-(4-methoxyphenyl)-2-phenylethanedione

[0341] [ka]

[0342] 25.0 g of the anisole solution of phenylglyoxylic acid chloride obtained in Synthesis Example 52 was dissolved in 35 g of methylene chloride and the temperature was adjusted to 0°C. 4.3 g of aluminum chloride was added and stirred at 0°C for 2 hours. 35 g of purified water was added and stirred for 10 minutes, followed by separation. The resulting organic layer was washed twice with 30 g of purified water, and the recovered organic layer was concentrated. The solvent was removed from the resulting organic layer, and the residue was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)) to obtain 5.6 g of 1-(4-methoxyphenyl)-2-phenylethanedione.

[0343] (Synthesis Example 54) Synthesis of 1-(4-hydroxyphenyl)-2-phenylethanedione

[0344] [ka]

[0345] 5.0 g of 1-(4-methoxyphenyl)-2-phenylethanedione was dissolved in 95 ml of acetic acid. 33.2 g of 48% by weight HBr aqueous solution was added dropwise at 70°C over 10 minutes. After the addition, the mixture was stirred at 110°C for 70 hours. 150 g of water was then added to crystallize the mixture. The crystals were filtered, washed with 250 g of water, and dried to obtain 4.1 g of 1-(4-hydroxyphenyl)-2-phenylethanedione.

[0346] (Synthesis Example 55) Synthesis of 2,2-dimethoxy-1-(4-methacryloxyphenyl)ethan-1-one (Compound C6)

[0347] [ka]

[0348] 4.0 g of 1-(4-hydroxyphenyl)-2-phenylethanedione and 0.10 g of sulfuric acid were dissolved in 12 g of methanol and the temperature was adjusted to 25°C. 2.2 g of trimethyl orthoformate was added dropwise and the mixture was stirred for 3 hours. 0.6 g of triethylamine was added at 30°C and the mixture was stirred for 5 minutes, after which the solvent was distilled off. 25 g of acetonitrile, 4.5 g of triethylamine, and 0.11 g of dimethylaminopyridine were added to the resulting residue, and then 6.8 g of methacrylic anhydride diluted with 5.0 g of acetonitrile was added dropwise at room temperature. After the addition, the mixture was stirred for 2 hours at 25°C, and then 64 g of a 3% by weight aqueous solution of NaHCO3 was added and the mixture was stirred for 5 minutes. The residue is then extracted with 32 g of ethyl acetate, washed three times with 10 g of water, and the collected organic layer is concentrated. The resulting organic layer is evaporated and then purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)) to obtain 4.3 g of 2,2-dimethoxy-1-(4-methacryloxyphenyl)ethan-1-one (compound C6).

[0349] <Synthesis of Compound E1 Constituting Unit E> (Synthesis Example 56) Synthesis of 4-vinylphenyl-triphenyltin (Compound E1)

[0350] [ka]

[0351] A flask from which moisture had been removed was charged with 1.2 g of magnesium and 6 g of THF. A solution of 6.0 g of 4-vinylbromobenzene dissolved in 12.0 g of THF was added dropwise over 1 hour. After stirring for 1 hour, the resulting 4-vinylphenylmagnesium bromide solution was added dropwise over 30 minutes at 5°C to a flask containing 7.3 g of triphenyltin chloride and 36 g of THF. After stirring for 30 minutes, 600 g of 1% by weight aqueous ammonium chloride solution was added and stirred for an additional 10 minutes. The THF was then distilled off, and the resulting organic layer was extracted with 60 g of toluene. The resulting organic layer was washed three times with 60 g of pure water. The solvent was then distilled off from the organic layer, which was then purified by column chromatography (ethyl acetate / hexane = 5 / 95 (volume ratio)) to obtain 5.6 g of 4-vinylphenyl-triphenyltin (Compound E1).

[0352] <Synthesis of Compound E2, which constitutes Unit E> (Synthesis Example 57) Synthesis of 4-isopropenylphenyl-triphenyltin (Compound E2)

[0353] [ka]

[0354] The same procedure as in Synthesis Example 56 was carried out except that 4-isopropenylbromobenzene was used instead of 4-vinylbromobenzene, to obtain 7.1 g of 4-isopropenylphenyl-triphenyltin (Compound E2).

[0355] <Synthesis of Compound E3, which constitutes Unit E> (Synthesis Example 58) Synthesis of 4-vinylphenyl-tributyltin (Compound E3)

[0356] [ka]

[0357] The same procedure as in Synthesis Example 56 was carried out except that tributyltin chloride was used instead of triphenyltin chloride, to obtain 5.1 g of 4-vinylphenyl-tributyltin (Compound E3).

[0358] <Synthesis of Compound E4, which constitutes Unit E> (Synthesis Example 59) Synthesis of 4-vinylphenyl-triphenylgermane (Compound E4)

[0359] [ka]

[0360] The same procedure as in Synthesis Example 56 was carried out except that triphenylgermanium chloride was used instead of triphenyltin chloride, to obtain 3.1 g of 4-vinylphenyl-tributylgermane (Compound E4).

[0361] <Synthesis of Compound F1, which constitutes Unit F> Synthesis Example 60: Synthesis of 1-trifluoromethyl-2-bromoethanol

[0362] [ka]

[0363] 6.0 g of 1-bromo-3,3,3-trifluoroacetone was dissolved in 28 g of THF, 0.3 g of lithium aluminum hydride was added, and the mixture was stirred at room temperature for 3 hours. 6 g of purified water was then added while checking for hydrogen generation, and the mixture was stirred for an additional 10 minutes. A 5% by mass aqueous solution of sodium oxalate was added, and the mixture was stirred for 10 minutes. 30 g of ethyl acetate was then added and the mixture was separated. The mixture was washed three times with 10 g of water, and the collected organic layer was concentrated to obtain 5.9 g of 1-trifluoromethyl-2-bromoethanol.

[0364] (Synthesis Example 61) Synthesis of 1-trifluoromethyl-2-methacryloxyethanol (Compound F1)

[0365] [ka]

[0366] 5.0 g of 1-trifluoromethyl-2-bromoethanol was dissolved in 20 g of DMF, to which 3.9 g of potassium carbonate and 3.3 g of methacrylic acid were added, followed by stirring at 80°C for 3 hours. 20 g of purified water was then added and the mixture was stirred for an additional 10 minutes. 30 g of ethyl acetate was added and the mixture was separated. The mixture was then washed with 10 g of 1% by mass aqueous hydrochloric acid, and then washed three times with 10 g of water. The collected organic layer was concentrated and purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)) to obtain 4.2 g of 1-trifluoromethyl-2-methacryloxyethanol (compound F1).

[0367] <Synthesis of Compound F2, which constitutes Unit F> (Synthesis Example 62) Synthesis of 1,3,5-triiodophenyl methacrylate (Compound F2)

[0368] [ka]

[0369] The same procedure as in Synthesis Example 46 was carried out except that 1,3,5-triiodophenol was used instead of 1-(4-hydroxyphenyl)-2,2-dimethyl-1-propanone, to obtain 4.3 g of 1,3,5-triiodophenyl methacrylate (compound F2).

[0370] <Synthesis of Polymer 1> (Synthesis Example 63) Synthesis of polymer a1

[0371] [ka]

[0372] 3.0 g of compound a1 constituting unit A, 1.8 g of compound B1 constituting unit B, 2.1 g of compound E1 constituting unit E, and 0.71 g of dimethyl-2,2'-azobis(2-methylpropionate) and 0.15 g of α-thioglycerol as polymerization initiators 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 mixture of 4 g of γ-butyrolactone and 4 g of cyclohexanone preheated to 80°C. After 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 filtration, the mixture was 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 1. Although the unit ratios of the polymers are disclosed above and below, the polymers of some embodiments of the present invention are not limited thereto.

[0373] (Synthesis Example 64) Synthesis of Polymer 1 [ka]

[0374] 2.0 g of polymer a1 obtained in Synthesis Example 63 above and 1.0 g of sodium 2-hydroxysulfonate were added to a mixed solution of 30 g of methylene chloride and 10 g of pure water, and the mixture was stirred at 25°C for 1 hour. After stirring, the mixture was separated, and 1.0 g of sodium 2-hydroxysulfonate and 10 g of pure water were added again, and the mixture was stirred at 25°C for 30 minutes. This process was repeated three times, after which the mixture was separated and the recovered organic layer was concentrated. The solvent in the resulting organic layer was distilled off, and the mixture was dispersed and washed with isopropyl alcohol to obtain 1.5 g of polymer 1.

[0375] (Synthesis Example 65) Synthesis of Polymer 2 [ka]

[0376] 1.4 g of Polymer 2 is obtained by carrying out the same procedure as in Synthesis Example 64 above, except that 2,3-dihydroxypropanesulfonic acid is used instead of 2-hydroxysulfonic acid.

[0377] (Synthesis Example 66) Synthesis of Polymer 3 [ka]

[0378] 1.6 g of Polymer 3 is obtained by carrying out the same procedure as in Synthesis Example 48 above, except that 3-[N,N-bis(2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid is used instead of 2-hydroxysulfonic acid.

[0379] <Synthesis of Polymers 4 to 13 and Comparative Polymers 1 and 2> (Synthesis Example 67) Synthesis of Polymers 4 to 13 and Comparative Polymers 1 and 2 Following the procedure of Synthesis Example 46, polymers 4 to 13 and comparative polymers 1 and 2 were synthesized using the compounds A1 to A5, a1, and a2 constituting unit A, the compounds B1, B2, and B4 constituting unit B, the compounds C1, C2, and C6 constituting unit C, the following compound D constituting unit D, the compounds E1 to E3 constituting unit E, and the compounds F1 to F2 constituting unit F. Details of each synthesized polymer are shown in Table 1. Compound D: 4-hydroxyphenyl methacrylate

[0380] [Table 1]

[0381] <Preparation of Resist Composition> 50 mg of either Polymers 1, 4 to 6, or 8, or Comparative Polymers 1 and 2, was dissolved in a solvent containing cyclohexanone, ethyl lactate, and γ-butyrolactone in a 5:5:1 ratio to prepare resist composition samples 1 to 7 of Examples 1 to 5 and Comparative Examples 1 and 2. The polymers used are shown in Tables 2 and 3.

[0382] <Preparation of developer> The developer was prepared as follows. (1) Resist composition samples 1 to 7, in which the above polymers 1, 4 to 6, and 8 and comparative polymers 1 and 2 were dissolved, were used to prepare films coated with the composition to a thickness of 100 nm by spin coating. (2) An aqueous acetonitrile solution having an acetonitrile concentration of 0 to 80% by mass is prepared. (3) Each film obtained in (1) above is immersed in each aqueous acetonitrile solution, and the minimum concentration of acetonitrile in the aqueous acetonitrile solution at which the composition applied to the film is completely dissolved within 30 seconds is determined. (4) The aqueous acetonitrile solution obtained in (3) above is used as a developer for each resist composition sample.

[0383] <Electron beam sensitivity evaluation> The resist composition sample 1 is spin-coated onto a silicon wafer. This is pre-baked on a hot plate at 110°C for 1 minute to obtain a substrate with a 30 nm thick coating film. A 50 nm line pattern with a 160 nm pitch is written onto the coating film on the substrate using an electron beam lithography system (Elionix ELS-F100T) with a 125 keV electron beam. After electron beam irradiation, the substrate is post-exposure baked (PEB) on a hot plate at 90°C for 1 minute. The substrate is then developed for 1 minute using a patterning developer in which the acetonitrile concentration of the developer optimized for each polymer is increased by 5% by mass, followed by rinsing with pure water to obtain a 50 nm line pattern. The irradiation dose at this time is E max [μC / cm 2 The resulting 50 nm line pattern is observed using a scanning electron microscope (SEM) (S-5500 manufactured by Hitachi High-Technologies Corporation) to measure the LWR. The sensitivity and LWR were evaluated in the same manner as above for Samples 2 to 7. The sensitivity and LWR of each of Resist Composition Samples 2 to 7 were compared using the sensitivity and LWR of Resist Composition Sample 1 (Comparative Example 1) as the reference values, and the results obtained as relative sensitivity and relative LWR are shown in Table 2.

[0384] [Table 2]

[0385] The results of Examples 1 and 2 show that both polymers have a hydroxyl group in the anion of unit A, and therefore the hydroxyl group in the anion can react with unit B. Therefore, in Examples 1 and 2, the reaction efficiency is improved, and sensitivity can be increased by 15% or more compared to Comparative Example 1. Furthermore, in the polymer having a hydroxyl group in the anion of unit A, the acid anion becomes part of the polymer by reacting with unit B, which significantly improves acid diffusion controllability and enables a reduction in LWR by 30% or more compared to Comparative Example 1.

[0386] Examples 3 and 4 have the same cationic structure as Comparative Example 2, but can achieve a sensitivity improvement of 15% or more compared to Comparative Example 2. Comparative Example 2 has higher sensitivity than Comparative Example 1, but the LWR is 20% larger than Comparative Example 1. However, since Examples 3 and 4 use a polymer having a hydroxyl group in the anion of unit A, they have better sensitivity than Comparative Example 1 and can achieve a LWR reduction of 30% or more.

[0387] The results of Example 5 show that anions having a thiol group can improve sensitivity and reduce LWR compared to the reference example, similar to anions having a hydroxyl group.

[0388] <Synthesis of polymers 14-20> (Synthesis Example 68) Synthesis of Polymers 14 to 21 Following the procedure of Synthesis Example 46, the above compounds A7 to A10 constituting unit A were synthesized. Polymers 14 to 21 were synthesized using the above compounds B1, B2, and B4 constituting unit B, the above compounds C1, C2, and C6 constituting unit C, the above compound E1 constituting unit E, and the following compound K constituting unit K. Details of each synthesized polymer are shown in Table 3. Compound K: 9-(4-methacryloxyphenyl)dibenzothiophenium-2,4,6-trifluorobenzoate

[0389] [Table 3]

[0390] [Examples 6 to 13] <Preparation of Resist Composition> 50 mg of any of the above polymers 4, 14 to 21 was dissolved in a solvent containing cyclohexanone, ethyl lactate, and γ-butyrolactone in a ratio of 5:5:1 to prepare resist composition samples 8 to 16 of Examples 6 to 14. The polymers used are shown in Table 4.

[0391] <Preparation of developer> The developer was prepared as follows. (1) Using resist composition samples 8 to 15 in which the above polymers 4 and 14 to 20 are dissolved, films are prepared by applying the composition to a thickness of 100 nm by spin coating. (2) An aqueous acetonitrile solution having an acetonitrile concentration of 0 to 80% by mass is prepared. (3) Each film obtained in (1) above is immersed in each aqueous acetonitrile solution, and the minimum concentration of acetonitrile in the aqueous acetonitrile solution at which the composition applied to the film is completely dissolved within 30 seconds is determined. (4) The aqueous acetonitrile solution obtained in (3) above is used as a developer for each resist composition sample.

[0392] <Electron beam-UV sensitivity evaluation> The resist composition sample 8 is spin-coated onto a silicon wafer. This is pre-baked on a hot plate at 110°C for 1 minute to obtain a substrate with a 30 nm thick coating film. A 50 nm line pattern with a 160 nm pitch is written onto the coating film on the substrate using an electron beam lithography system (Elionix ELS-F100T) with a 125 keV electron beam. After electron beam irradiation, the substrate is post-exposure baked (PEB) on a hot plate at 90°C for 1 minute. Then, a 395 nm UV-LED is used to irradiate the substrate with 1000 mJ / cm. 2 The entire surface was irradiated with an exposure dose of E. The patterning was then carried out for 1 minute using a developer optimized for each polymer, with the acetonitrile concentration increased by 5% by mass, and the substrate was then rinsed with pure water to obtain a 50 nm line pattern. max [μC / cm 2 The resulting 50 nm line pattern is observed using a scanning electron microscope (SEM) (S-5500 manufactured by Hitachi High-Technologies Corporation) to measure the LWR. The sensitivity and LWR were evaluated in the same manner as above for Samples 9 to 16. The sensitivity and LWR of each of Resist Composition Samples 9 to 16 were compared using the sensitivity and LWR of Resist Composition Sample 8 as the reference values, and the results obtained as relative sensitivity and relative LWR are shown in Table 4.

[0393] [Table 4]

[0394] Example 6 and Examples 7 to 10, which have the same composition ratio of units A, B, and E, were compared. The hydroxyl group of the anion of compounds A7 to A10 contained in Examples 7 to 10 is bonded to unit B by an acid-catalyzed reaction with an acid generated by electron beam irradiation. Units B also bond to each other by an acid-catalyzed reaction. Furthermore, the acetal moiety of the onium salt in unit A is hydrolyzed by water generated by the acid-catalyzed reaction to form a ketone derivative, shifting the wavelength of light absorption to longer wavelengths, and the polymer changes to have UV absorption at 395 nm. Therefore, the sensitivity of Examples 7 to 10 is improved even though the composition is the same as that of Example 6, due to the additional acid generated by full-surface UV exposure after EB irradiation.

[0395] Comparing Example 6 with Examples 7 to 13, it is estimated that even though sensitivity to UV irradiation is improved, the influence of acid diffusion due to UV irradiation is almost negligible because of the good LWR.Comparing Example 6 with Examples 7 to 13, patterning can be performed with the same level of LWR, so there is no trade-off between sensitivity and LWR.

[0396] Comparing Example 8 and Example 14, it can be seen that the addition of Unit K reduces sensitivity by suppressing the action of the acid generated from Unit A, but also tends to reduce LWR by suppressing acid diffusion, which is effective when high resolution is required. [Industrial Applicability]

[0397] 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 that has excellent properties in terms of sensitivity, resolution, and pattern performance, as well as a resist composition containing the polymer.

Claims

1. a unit A having an onium salt structure and generating an acid when irradiated with a particle beam or electromagnetic wave; and a unit B having a structure that bonds via an acid-catalyzed reaction, The unit A is a unit represented by the following formula (1): 【Chemical 1】 (In the 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 1 to 6 carbon atoms; １ at least one hydrogen atom in the alkyl group and the alkenyl group may be substituted with a substituent; 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; 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 1 to 6 carbon atoms, wherein at least one methylene group in Sp is optionally substituted with a divalent heteroatom-containing group, M ＋ is a sulfonium ion or an iodonium ion, X － is a monovalent anion having an organic group containing at least one selected from the group consisting of a hydroxyl group and a sulfanyl group. The polymer wherein the unit B 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 (2) at any position of the compound: 【Chemistry 2】 【change】 (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; n 1 is an integer of 0 or 1; n 4 and n 5 are each an integer of 1 to 2, and n 4 +n 5 is an integer of 2 to 4; When n 4 is 1, n 2 is an integer of 0 to 4, and when n 4 is 2, n 2 is an integer of 0 to 6; When n 5 is 1, n 3 is an integer of 0 to 4, and when n 5 is 2, n 3 is an integer of 0 to 6; When n 2 is 2 or more and R 2 is an electron-donating group or an electron-withdrawing group, two R 2 s may form a ring structure together directly by 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, When n3 is 2 or more and R3 is an electron-donating group or an electron-withdrawing group, the two R3s may form a ring structure together directly by 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. In the general formula (II), R 4 is independently any one selected from the group consisting of a hydrogen atom; an electron-donating group; and an electron-withdrawing group; At least one of R 4 is the electron-donating group; R 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, at least one methylene group in R 5 may be substituted with a divalent heteroatom-containing group, and R 5 may form a ring structure together with the benzene ring to which the hydroxymethylene group having R 5 is bonded, n 6 is an integer from 0 to 7; n 7 is 1 or 2, and when n 7 is 1, n 6 is an integer of 0 to 5, and when n 7 is 2, n 6 is an integer of 0 to 7; When n6 is 2 or more and R4 is an electron-donating group or an electron-withdrawing group, the two R4s may form a ring structure together directly by 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. 【Chemistry 3】 (In the formula (2), R 1 , L and Sp are selected from the same options as R 1 , L and Sp in general formula (1), respectively; * indicates the bonding site with the compound represented by the general formula (I) or (II).

2. at least one hydroxyl group of the organic group is derived from any one selected from the group consisting of primary alcohols, secondary alcohols, and tertiary alcohols; 2. The polymer according to claim 1, wherein the sulfanyl group of at least one of the organic groups is derived from any one selected from the group consisting of primary thiols, secondary thiols, and tertiary thiols.

3. at least one hydroxyl group of the organic group is derived from a primary alcohol or a secondary alcohol; 3. The polymer according to claim 1, wherein the sulfanyl group of at least one of the organic groups is derived from a group selected from the group consisting of primary thiols and secondary thiols.

4. X － is any one selected from the group consisting of an alkyl sulfate anion having at least one hydroxyl group and a sulfanyl group; an aryl sulfate anion having at least one hydroxyl group and a sulfanyl group; an alkyl sulfonate anion having at least one hydroxyl group and a sulfanyl group; an aryl sulfonate anion having at least one hydroxyl group and a sulfanyl group; an alkyl carboxylate anion having at least one hydroxyl group and a sulfanyl group; an aryl carboxylate anion having at least one hydroxyl group and a sulfanyl group; a dialkylsulfonylimide anion having at least one hydroxyl group and a sulfanyl group; a trialkylsulfonate methide anion having at least one hydroxyl group and a sulfanyl group; and a tetrakisphenylborate anion having at least one hydroxyl group and a sulfanyl group; X － 4. The polymer according to claim 1, wherein at least one hydrogen atom of the alkyl group and the aryl group may be substituted with a fluorine atom.

5. X － is either an alkylsulfonate anion having at least one hydroxyl group and a sulfanyl group, or an arylsulfonate anion having at least one hydroxyl group and a sulfanyl group, X － The polymer according to claim 4 , wherein at least one hydrogen atom of the alkyl group and the aryl group may be substituted with a fluorine atom.

6. the polymer further comprises a unit C; the unit C has a radical-generating structure containing at least one multiple bond selected from the group consisting of a multiple bond between carbon atoms and a multiple bond between a carbon atom and a heteroatom, and generates a second radical when irradiated with a particle beam or an electromagnetic wave, The polymer according to any one of claims 1 to 5, wherein the multiple bond in the radical-generating structure is not a multiple bond contained in a benzene-based aromatic compound.

7. The polymer according to claim 6, wherein the multiple bond is at least one of the bonds shown below: 【Chemistry 4】

8. The polymer according to claim 6 or 7, wherein the unit C has any one selected from the group consisting of an alkylphenone skeleton, an acyloxime skeleton, and a benzil ketal skeleton.

9. The polymer according to any one of claims 1 to 8, wherein the unit A is represented by the following formula (3): 【Chemistry 5】 (In the general formula (3), R １ , L, Sp and X － are R in the general formula (1), respectively. １ , L, Sp and X － are selected from the same options as 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 1 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 the formula (I) may be substituted with a divalent heteroatom-containing group; R 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 1 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 the formula (I) may be substituted with a divalent heteroatom-containing group; R ６ａ and two R ６ｂ Two of the may form a ring structure with the sulfur atom to which they are bonded 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.

10. Said M ＋ X － The polymer according to any one of claims 1 to 8, wherein is represented by the following general formula (11) or the following formula (12): 【Chemistry 6】 【Chemistry 7】 (In the formulas (11) and (12), The R １４ are each independently any one selected from the group consisting of an alkyl group, a hydroxy group, a mercapto group, an alkoxy group, an aryloxycarbonyl group, a heteroaryloxycarbonyl group, an arylsulfanylcarbonyl group, a heteroarylsulfanylcarbonyl group, an arylsulfanyl group, a heteroarylsulfanyl group, an alkylsulfanyl group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group, a (poly)alkyleneoxy group, an alkylamino group, and a dialkylcyano group; R １７ and R １８ are each independently any one selected from the group consisting of an alkyl group, a hydroxy group, a mercapto group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, a heteroarylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a heteroaryloxycarbonyl group, an arylsulfanylcarbonyl group, a heteroarylsulfanylcarbonyl group, an arylsulfanyl group, a heteroarylsulfanyl group, an alkylsulfanyl group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group, an alkylsulfinyl group, an arylsulfinyl group, a heteroarylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a heteroarylsulfonyl group, an arylsulfonyl group, a heteroarylsulfonyl group, a (poly)alkyleneoxy group, an alkylamino group, a dialkylamino group, a nitro group, and a halogen atom; The R １４ , R １７ and R １８ has 1 to 12 carbon atoms, and １４ , R １７ and R １８ When has a hydrogen atom, the hydrogen atom may be substituted with a substituent, R １９ is 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 1 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; The R １９ and the R １８ and the benzene ring to which R １７ may form a ring structure together with any of the benzene rings to which is bonded, either directly via a single bond or via a sulfur atom to which is bonded, through any one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group and a methylene group, The R １４ , R １７ and R １８ has methylene groups, at least one of which may be substituted with a divalent heteroatom-containing group; The R 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 1 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; The R 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, The R １５ and R １６ at least one methylene group in the formula (I) may be substituted with a divalent heteroatom-containing group; L ３ 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; a sulfinyl group, a sulfonyl group, and a carbonyl group; R １４ , R １８ and R １９ any one hydrogen atom in the formula (1) is replaced with a bond to Sp, Y is an oxygen atom or a sulfur atom, q is an integer from 0 to 4; f is an integer from 0 to 3; g is an integer from 1 to 5; j is an integer from 0 to 2, k is an integer from 1 to 4, (However, the above R １９ and the R １８ and the benzene ring to which R １７ is bonded to and forms a ring structure together with the sulfur atom, in the formula (11), q is 0 to 3 or j is 0 to 2, and in the formula (12), q is 0 to 3 or j is 0 to 1. At least one of the benzene rings in the formulas (11) and (12) may be a 6-membered heteroaromatic ring having a heteroatom in the ring, and R １４ When the benzene ring bonded to the heteroaromatic ring is the heterocyclic ring, k may be 0 to 4. In the formulas (11) and (12), R １４ When there are two or more １４ two of which may be linked to each other to form a ring structure, X － is X in the formula (1). － are selected from the same options.)

11. The polymer according to any one of claims 6 to 10, wherein the unit C is represented by at least one of the following general formulas (4): 【Chemistry 8】 (In the general formula (4), R １ , L, Sp and X － are R in the general formula (1), respectively. １ , L, Sp and X － are selected from the same options as R ７ are each independently a hydrogen atom; a hydroxy group; ａ (R ａ is a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms which may have a substituent, and R ａ At least one methylene group in the -OR group may be substituted with a divalent heteroatom-containing group; ａ and the R ａ a group in which at least one carbon-carbon single bond in -R is replaced with a carbon-carbon double bond; and ｂ (R ｂ is an aryl group having 6 to 14 carbon atoms which may have a substituent, or a heteroaryl group having 4 to 12 carbon atoms which may have a substituent; Two R's ７ 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, R ８ is -R ａ ;-R ｂ ;-OR ａ ;-SR ａ ;-OR ｂ ;-SR ｂ -OC(=O)R ａ -OC(=O)R ｂ -C(=O)OR ａ -C(=O)OR ｂ ;-OC(=O)OR ａ ;-OC(=O)OR ｂ ;-NHC(=O)R ａ ;-NR ａ C(=O)R ａ ;-NHC(=O)R ｂ ;-NR ｂ C(=O)R ｂ ;-NR ａ C(=O)R ｂ ;-NR ｂ C(=O)R ａ ; -N(R ａ ) ２ ; -N(R ｂ ) ２ ; -N(R ａ ) (R ｂ ); -SO ３ R ａ ;-SO ３ R ｂ ;-SO ２ R ａ ;-SO ２ R ｂ ; Said-R ａ a group in which at least one carbon-carbon single bond in ２ is an integer from 1 to 3, and m ２ When m is 1 １ is an integer from 0 to 4, and m ２ When is 2, m １ is an integer from 0 to 6, and m ２ When is 3, m １ is an integer from 0 to 8, m １ When is 2 or more, two R ８ 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.

12. The unit C is represented by the general formula (4), and R ７ 12. The polymer of claim 11, wherein at least one of the groups is a hydroxy group.

13. The polymer according to any one of claims 1 to 12, further comprising a unit D having an aryloxy group.

14. The polymer according to any one of claims 1 to 13, further comprising an organometallic compound-containing unit E having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi and Te.

15. The polymer according to any one of claims 1 to 14, further comprising a unit F having a halogen atom and represented by the following formula (7): 【Chemistry 9】 (In the general formula (7), R １ , L and Sp are R in the general formula (1), １ , L and Sp are selected from the same choices; R ｈ is any one 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 alkyleneoxy groups having 1 to 12 carbon atoms; optionally substituted linear, branched or cyclic alkenyl groups having 1 to 12 carbon atoms; optionally substituted linear, branched or cyclic alkenyleneoxy groups having 1 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, In addition, some or all of the hydrogen atoms substituted on the carbon atoms are substituted with fluorine atoms or iodine atoms.

16. A resist composition comprising the polymer according to any one of claims 1 to 15.

17. Further containing either an organometallic compound or an organometallic complex, 17. The resist composition according to claim 16, wherein the metal is at least one selected from the group consisting of Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, Rn, and Ra.

18. a resist film forming step of forming a resist film on a substrate using the resist composition according to claim 16 or 17; a photolithography step of exposing the resist film to particle beams or electromagnetic waves; a pattern formation step of developing the exposed resist film to obtain a photoresist pattern; A method for manufacturing a component comprising:

19. The method for manufacturing a member according to claim 18, wherein the development in the pattern formation step is carried out using an aqueous solution containing a water-soluble organic solvent.

20. The method for manufacturing a member according to claim 18 or 19, wherein in the photolithography step, after exposure to the particle beam or electromagnetic wave, irradiation with a second active energy ray having lower energy than the particle beam or electromagnetic wave is performed.

21. a step of applying a reversal pattern composition so as to cover at least the recesses of the photoresist pattern, and etching the resulting coating to expose the surface of the photoresist pattern; The method for manufacturing a member according to any one of claims 18 to 20, further comprising the step of removing the resist film from the exposed surface portion of the resist pattern to obtain a reverse pattern.

22. The method for manufacturing a member according to any one of claims 18 to 21, wherein the particle beam is an electron beam, and the electromagnetic wave is extreme ultraviolet radiation.

23. a resist film forming step of forming a resist film on a substrate using the resist composition according to claim 16 or 17; a photolithography step of exposing the resist film to particle beams or electromagnetic waves; and a pattern forming step of developing the exposed resist film to obtain a photoresist pattern.

24. 24. The pattern formation method according to claim 23, wherein the development in the pattern formation step is carried out using an aqueous solution containing a water-soluble organic solvent.

25. 25. The pattern formation method according to claim 23, wherein in the photolithography step, after exposure to the particle beam or electromagnetic wave, irradiation with a second active energy ray having lower energy than the particle beam or electromagnetic wave is performed.

26. a resist film forming step of forming a resist film on a substrate using the resist composition according to claim 16 or 17; a photolithography step of exposing the resist film to particle beams or electromagnetic waves; a pattern formation step of developing the exposed resist film to obtain a photoresist pattern; a step of applying a reversal pattern composition so as to cover at least the recesses of the photoresist pattern, and etching the resulting coating to expose the surface of the photoresist pattern; and removing the resist film from the exposed surface portion of the photoresist pattern to obtain a reverse pattern.

27. 27. The method for forming a reversal pattern according to claim 26, wherein the development in the pattern formation step is carried out using an aqueous solution containing a water-soluble organic solvent.

28. 28. The method for forming a reversal pattern according to claim 26, wherein in the photolithography step, after exposure to the particle beam or electromagnetic wave, a second active energy ray having lower energy than the particle beam or electromagnetic wave is irradiated.

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