A polymer, a resist composition containing the polymer, and a method for manufacturing a device using the same.

Abstract

To provide a polymer for use in a resist composition having excellent sensitivity, a resist composition containing the polymer, and a method for producing a device using the resist composition.SOLUTION: A polymer comprises a unit A having an onium salt structure, wherein the unit A is a unit represented by the following formula (1) (wherein R1, L, Sp, X1-, and M1+ each have a specific structure).SELECTED DRAWING: None

Description

[Technical Field]

[0001] Some aspects of the present invention relate to polymers used in resist compositions. Furthermore, some aspects of the present invention relate to resist compositions containing the above-mentioned polymers and methods for manufacturing devices using the resist compositions. [Background technology]

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

[0003] As devices become more highly integrated, the demand for miniaturization in lithography technology is increasing, and there is a growing trend to use very short wavelength light such as KrF excimer lasers (wavelength 248 nm), ArF excimer lasers (wavelength 193 nm), extremely short ultraviolet light (EUV, wavelength 13.5 nm), and electron beams (EB) for irradiation. Since lithography technology using these short wavelengths of light, especially EUV or electron beams, enables single-patterning manufacturing, the need for resist compositions that exhibit high sensitivity to EUV or electron beams is expected to increase even further in the future.

[0004] With the shortening of the wavelength of exposure light sources, resist compositions are required to have improved lithographic characteristics, such as sensitivity to the exposure light source and resolution that can reproduce patterns of fine dimensions. Chemically amplified resists are known as resist compositions that satisfy these requirements (Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-90637 [Overview of the project] [Problems that the invention aims to solve]

[0006] Some aspects of the present invention aim to provide polymers for use in resist compositions with excellent sensitivity by not only utilizing acids generated from an acid generator by irradiation with particle beams or electromagnetic waves, particularly electron beams or EUV, but also by directly utilizing reactions that occur simultaneously with the acid catalytic reaction by irradiation with electron beams or EUV. Some aspects of the present invention aim to provide a resist composition containing the above-mentioned polymer, and a method for manufacturing a device using the resist composition. [Means for solving the problem]

[0007] The present inventors conducted diligent studies to solve the above problems and found that using a polymer containing a specific onium salt structure unit A having an acetal moiety or thioacetal moiety as the polymer of a resist composition results in high sensitivity, leading to the completion of several embodiments of the present invention. In particular, they found that by using a polymer for a resist composition used in a device manufacturing method comprising the steps of: coating the above composition onto a substrate to form a resist film; irradiating the resist film with a first active energy ray; irradiating the resist film after irradiation with the first active energy ray with a second active energy ray; and developing the resist film after irradiation with the second active energy ray to obtain a pattern, the decomposition of the onium salt structure unit A in the polymer of the resist composition is promoted by the second active energy ray, resulting in high sensitivity.

[0008] One aspect of the present invention for solving the above problems is a polymer comprising a unit A having a specific onium salt structure.

[0009] The above unit A is the unit shown by the following formula (1). [ka]

[0010] In the above general formula (1), R 1 R is selected from the group consisting of a hydrogen atom; a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched, or cyclic alkenyl group having 2 to 6 carbon atoms. 1 At least one hydrogen atom in the alkyl and alkenyl groups within the above-mentioned group may be substituted with a substituent.

[0011] L is selected from the group consisting of a direct bond, a carbonyloxy group, a carbonylamino group, a phenylenediyl group, a naphthalenediyl group, a phenylenediyloxy group, a naphthalenediyloxy group, a phenylenediylcarbonyloxy group, a naphthalenediylcarbonyloxy group, a phenylenediyloxycarbonyl group, and a naphthalenediyloxycarbonyl group.

[0012] Sp is one of the following: a direct bond; a linear, branched, or cyclic alkylene group having 1 to 6 carbon atoms, which may have substituents; or a linear, branched, or cyclic alkenylene group having 2 to 6 carbon atoms, which may have substituents; and at least one methylene group in Sp may be substituted with a divalent heteroatom-containing group.

[0013] X1 - It is a monovalent anion.

[0014] In the above formula (1) M1 + However, it can be expressed by either the following general formula (2) or the following general formula (3). [ka]

[0015] In equation (2) above, R 11 and R 12Each is independently any one selected from the group consisting of a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms which may have a substituent; a linear, branched or cyclic alkenyl group having 2 to 12 carbon atoms which may have a substituent; an aryl group having 6 to 14 carbon atoms which may have a substituent; and a heteroaryl group having 4 to 12 carbon atoms which may have a substituent.

[0016] The above R 11 and R 12 and any two or more of the aryl groups to which the sulfonium group is attached may form a ring structure together with the sulfur atom to which they are attached, either directly by a single bond or through any one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group and a methylene group.

[0017] The above R 11 and R 12 At least one methylene group in may be substituted with a divalent heteroatom-containing group.

[0018] R 13 and R 14 are each independently any one selected from the group consisting of an alkyl group, a hydroxy group, a mercapto group, an alkyleneoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkyleneoxycarbonyl group, an aryloxycarbonyl group, an arylsulfanylcarbonyl group, an arylsulfanyl group, an alkylsulfanyl group, an aryl group, a heteroaryl group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a (meth)acryloyloxy group, a hydroxy(poly)alkyleneoxy group, an amino group, a cyano group, a nitro group and a halogen atom, and when having carbon, the number of carbon atoms is 1 to 12, and these may have a substituent. One R 14 may form a heterocyclic structure with the aryl group to which the R 14 is attached through any one selected from the group consisting of a direct bond, a methylene group, an oxygen atom, a sulfur atom and a nitrogen atom-containing group.

[0019] R 15 and R 16 Each of these is independently selected from the group consisting of: optionally substituted linear, branched, or cyclic alkyl groups having 1 to 12 carbon atoms; optionally substituted linear, branched, or cyclic alkenyl groups having 2 to 12 carbon atoms; optionally substituted aryl groups having 6 to 14 carbon atoms; and optionally substituted heteroaryl groups having 4 to 12 carbon atoms. The above R 15 and R 16 These elements may be bonded to each other directly by single bonds, or via any of the elements selected from the group consisting of oxygen atoms, sulfur atoms, and alkylene groups, to form a ring structure. The above R 15 and R 16 At least one methylene group may be substituted with a divalent heteroatom-containing group.

[0020] L 2 This is one of the groups selected from the following: directly bonded; linear, branched, or cyclic alkylene groups having 1 to 12 carbon atoms; alkenylene groups having 2 to 12 carbon atoms; arylene groups having 6 to 14 carbon atoms; heteroarylene groups having 4 to 12 carbon atoms; and groups in which these groups are bonded via oxygen, sulfur, or nitrogen atom-containing groups.

[0021] L 3 This is selected from the group consisting of direct bonds, methylene groups, sulfur atoms, nitrogen atom-containing groups, and oxygen atoms.

[0022] Y is either an oxygen atom or a sulfur atom.

[0023] h is an integer between 1 and 2, and i is an integer between 1 and 3. j is an integer between 0 and 3 when h is 1, and between 0 and 5 when h is 2. k is an integer between 0 and 4 when i is 1, between 0 and 6 when i is 2, and between 0 and 8 when i is 3. R 11 , R 12 and R 14 Any one of the hydrogens in R14 The hydrogen atom on the aryl ring to which is bonded is replaced by the bond with Sp in formula (1) above.

[0024] In equation (3) above, R 11 ~R 16 , L 2 And Y and each independently correspond to R in equation (2) above. 11 ~R 16 , L 2 The same options are selected for each of Y.

[0025] h is an integer between 1 and 2, and i is an integer between 1 and 3. j is an integer between 0 and 4 when h is 1, and between 0 and 68 when h is 2. k is an integer between 0 and 5 when i is 1, between 0 and 7 when i is 2, and between 0 and 9 when i is 3. L 4 and L 5 Each of these is independently selected from the group consisting of a direct bond, an alkenylene group with 2 carbon atoms, an alkynylene group with 2 carbon atoms, and a carbonyl group.

[0026] Furthermore, a polymer according to one embodiment of the present invention further comprises at least one of the following units: unit B having a structure that undergoes dehydration by an acid-catalyzed reaction; and unit C containing an organometallic compound having a metal atom. The above unit B is a unit bonded to the Sp group of formula (4) below at either position in the compound represented by the following general formula (I) or (II).

[0027] [ka]

[0028] In the above general formula (I), R 2 and R 3 Each of these is independently selected from the group consisting of electron-donating groups and electron-withdrawing groups.

[0029] E is selected from the group consisting of direct bonds; oxygen atoms; sulfur atoms; and methylene groups.

[0030] n 1 is an integer, either 0 or 1. n 4 and n 5 These are integers from 1 to 2, and n 4 +n 5 The answer is 2-4. n 4 When n is 1 2 n is an integer between 0 and 4. 4 When n is 2 2 is an integer between 0 and 6. n 5 When n is 1 3 n is an integer between 0 and 4. 5 When n is 2 3 is an integer between 0 and 6. n 2 If R is 2 or more 2 When is an electron-donating group or an electron-withdrawing group, two R 2 However, they may form a ring structure with each other either directly by single bonds or via any of the group selected from oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups. n 3 If R is 2 or more 3 When is an electron-donating group or an electron-withdrawing group, two R 3 However, they may form a ring structure with each other either directly by single bonds or via any of the group selected from oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups.

[0031] In the above general formula (II), R 4 Each of these is independently selected from the group consisting of electron-donating groups and electron-withdrawing groups.

[0032] R 4 At least one of them is the electron-donating group described above. R 5aR is selected from the group consisting of a hydrogen atom; a primary alkyl group which may have substituents; and a secondary alkyl group which may have substituents; and the above R 5a At least one methylene group may be substituted with a divalent heteroatom-containing group. R 5b is selected from the group consisting of a hydrogen atom; an optionally substituted alkyl group; and an optionally substituted alkenyl group, and the above R 5b At least one methylene group in the above R may be substituted with a divalent heteroatom-containing group, 5 is the R 5b A hydroxymethylene group having this property may form a ring structure together with a benzene ring to which it is bonded. n 6 The integer is between 0 and 7. n 7 is 1 or 2, and n 7 When n is 1 6 n is an integer between 0 and 5. 7 When n is 2 6 The integer is between 0 and 7. n 6 If R is 2 or more 4 When is an electron-donating group or an electron-withdrawing group, two R 4 However, they may form a ring structure with each other either directly by single bonds or via any of the group selected from oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups.

[0033] [ka]

[0034] In the above equation (4), R 1 L and Sp are R in the general formula (1) above, respectively. 1 , selected from the same options as L and Sp, and * indicates the binding site with the compound represented by the above general formula (I) or (II).

[0035] The metal in the above-mentioned organometallic unit C is preferably selected from the group consisting of Sn, Sb, Ge, Bi, Te, Al, Ni, Zn, Zr, and Hf.

[0036] One aspect of the present invention for solving the above problems is a resist composition containing the above polymer.

[0037] Another aspect of the present invention is a method for manufacturing a device, comprising the steps of: applying the above composition onto a substrate to form a resist film; irradiating the resist film with a first active energy ray; irradiating the resist film after irradiation with the first active energy ray with a second active energy ray; and developing the resist film after irradiation with the second active energy ray to obtain a pattern. [Effects of the Invention]

[0038] According to several aspects of the present invention, it is possible to provide a polymer having an onium salt structure that is suitably used as a resist composition for lithography processes using a first active energy ray such as a particle beam or electromagnetic wave and a second active energy ray such as ultraviolet light or visible light. Furthermore, it is possible to provide a resist composition that is highly sensitive to two-stage irradiation of a particle beam or electromagnetic wave, particularly an first active energy ray such as an electron beam or extreme ultraviolet light and a second active energy ray such as ultraviolet light or visible light, and a method for manufacturing a device using the same. [Modes for carrying out the invention]

[0039] In this invention, "particle beam or electromagnetic wave" includes not only electron beams (EB) and extreme ultraviolet (EUV), but also ultraviolet light such as KrF excimer laser light and ArF excimer laser light. Furthermore, in the present invention, "irradiation with particle beam or electromagnetic wave" means irradiating at least a portion of the polymer with a particle beam or electromagnetic wave. The present invention will be described in detail below, but is not limited thereto.

[0040] <1> polymer A polymer according to some aspects of the present invention is a polymer comprising a unit A having an onium salt structure that generates acid upon irradiation with a particle beam or electromagnetic beam. The onium salt of unit A has a specific structure such as an acetal or thioacetal, and therefore does not exhibit significant absorption to the second active energy ray, such as ultraviolet light or visible light. On the other hand, the acid generated by the first active energy ray, such as a particle beam or electromagnetic wave, deprotects the acetal or thioacetal of the onium salt without impairing its function as a photoacid generator, and the onium salt is converted into a ketone derivative. The ketone derivative has absorption to the first and second active energy rays. Therefore, when polymers of some embodiments of the present invention are used as a resist composition, irradiation with a first energy ray such as a particle beam or electromagnetic wave causes the onium salt structure of unit A to decompose, resulting in a large polarity change from ionic to nonionic, and generating acid. Furthermore, the onium salt structure of unit A in the composition irradiated with the first active energy ray undergoes a structural change due to the acid, converting it into a ketone derivative that absorbs the second active energy ray. Since acid is generated with high efficiency by irradiating the composition containing the ketone derivative with a second active energy ray such as ultraviolet light or visible light, the composition exhibits excellent sensitivity and pattern characteristics such as LWR. For this reason, polymers of some embodiments of the present invention are preferably used in a process having a two-stage irradiation, in which the portion irradiated with the first active energy ray is irradiated with the second active energy ray after irradiation with the first active energy ray. Since the ketone derivative is generated in the resist film in the irradiated portion irradiated with the first active energy ray, the amount of acid generated in the irradiated portion irradiated with the second active energy ray can be increased by further irradiating with the second active energy ray. The first radicals generated from unit A can form bonds with each other, and intramolecular cross-linking reactions can occur between the units A. When a pattern is formed using polymers according to some aspects of the present invention, excellent sensitivity and line edge roughness (LWR) characteristics are obtained. Furthermore, polymers according to some embodiments of the present invention include, as optional units, at least one of unit B having a structure that undergoes dehydration by the acid-catalyzed reaction and unit C containing the organometallic compound. When a polymer according to some embodiments of the present invention has the above-mentioned unit B, a dehydration reaction occurs at least within the molecule of unit B, between unit A and unit B, between units B themselves, and between unit B and a unit other than unit B, due to the acid generated by the decomposition of the onium salt structure of unit A. Therefore, when a polymer containing unit A and unit B is irradiated with particle beams or electromagnetic waves on at least a portion of the polymer, an anion and a first radical are generated from unit A by reduction. Some of the generated anion combines with a proton to form an acid. The acid acts as a catalyst, and a crosslinking reaction can occur by etherification or thioetherification through a reaction between unit A and unit B. Therefore, it is preferable that a polymer according to some embodiments of the present invention has unit B.

[0041] Furthermore, if the polymer according to some embodiments of the present invention has the above-mentioned unit C, the Lewis acidity of the metal may cause a decrease in the activity or deactivation of the acid produced by the decomposition of the above-mentioned unit A. As a result, it acts as an acid diffusion control agent, so it is preferable that the polymer according to some embodiments of the present invention has the above-mentioned unit C.

[0042] (Unit A) The above-mentioned unit A has a specific onium salt structure. More specifically, the onium salt structure is one in which at least a portion of the polymer undergoes polarity conversion by irradiation with particle beams or electromagnetic waves, and is an onium salt structure represented by the above general formula (2) or (3). Specifically, one example is the one shown in the following formula (1). In the present invention, "polarity conversion" refers to a change in polarity from ionic to nonionic, either directly or indirectly, due to irradiation with a particle beam or electromagnetic wave.

[0043] [ka]

[0044] In the above formula (1) M1 + However, it is represented by either of the following general formulas (2) and (3). By using a first polymer as the polymer of a resist composition, which includes a unit A having a specific onium salt structure with an acetal or thioacetal moiety, and a unit B having a structure that is dehydrated by an acid-catalyzed reaction, high sensitivity and suppression of linewise roughness (LWR) can be achieved.

[0045] [ka]

[0046] In equation (2) above, R 11 and R 12 Each of these is independently selected from the group consisting of: optionally substituted linear, branched, or cyclic alkyl groups having 1 to 12 carbon atoms; optionally substituted linear, branched, or cyclic alkenyl groups having 2 to 12 carbon atoms; optionally substituted aryl groups having 6 to 14 carbon atoms; and optionally substituted heteroaryl groups having 4 to 12 carbon atoms.

[0047] The above R 11 , R 12 Any two or more of the aryl groups to which the sulfonium group is bonded may form a ring structure with the sulfur atom to which they are bonded, either directly by a single bond or via any of the group selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group, and a methylene group. The above R 11 and R 12 At least one methylene group may be substituted with a divalent heteroatom-containing group. Examples of the above divalent heteroatom-containing groups 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 - Examples include, but are not limited to, one or a combination selected from the group consisting of these. However, it is preferable that there is no continuous connection of heteroatoms such as -O-O-, -S-S- and -O-S-. The above R 11 and R 12 At least one methylene group in is substituted with a divalent heteroatom-containing group. Examples of R 11 and R 12 include groups having a glycol chain or a thioglycol chain. Examples of the nitrogen atom-containing group include groups containing a nitrogen atom among the above divalent heteroatom-containing groups. Examples of the above R Sp include linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms. Examples of Ar Sp include aryl groups having 12 or fewer carbon atoms such as a phenyl group and a naphthyl group.

[0048] R 11 and R 12 Examples of the substituent in (hereinafter also referred to as "the first substituent") include a hydroxy group, a cyano group, a mercapto group, a carboxy group, an alkyl group (-R e ), an alkoxy group (-OR e ), an acyl group (-COR e ), an alkoxycarbonyl group (-COOR e ), an aryl group (-Ar), an aryloxy group (-OAr), an amino group, an alkylamino group (-NHR e ), a dialkylamino group (-N(R e )2), an arylamino group (-NHAr), a diarylamino group (-N(Ar)2), an N-alkyl-N-arylamino group (-NR e Ar), a phosphino group, a silyl group, a halogen atom, a trialkylsilyl group (-Si-(R e )3), a silyl group in which at least one alkyl group of the trialkylsilyl group is substituted with Ar, an alkylsulfanyl group (-SR e ) and an arylsulfanyl group (-SAr), etc., but are not limited to these. Re And Ar will be explained below.

[0049] R in the first substituent described above e Preferably, the alkyl group has 1 or more carbon atoms. More preferably, it has 20 or fewer carbon atoms. Specific examples of alkyl groups having 1 or more carbon atoms include, for example, 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-ethylexyl groups; alicyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantane-1-yl, adamantane-2-yl, norbornan-1-yl, and norbornan-2-yl groups; silyl group-substituted alkyl groups in which one of the hydrogen atoms is substituted with a trialkylsilyl group such as trimethylsilyl, triethylsilyl, and dimethylethylsilyl; and alkyl groups in which at least one of the hydrogen atoms is substituted with a cyano group or a fluoro group. The carbon-carbon single bond in the alkyl group described above may be replaced by a carbon-carbon double bond.

[0050] The Ar in the first substituent described above is preferably an aryl group or a heteroaryl group. A heteroaryl group is preferably an aryl group containing one or more heteroatoms in its ring structure. Specific examples of the above aryl group or heteroaryl group include phenyl group, biphenyl group, terphenyl group, quaterphenyl group, naphthyl group, anthryl group, phenantrenyl group, pentarenyl group, indenyl group, indacenyl group, acenaphthyl group, fluorenyl group, heptarenyl group, naphthacenyl group, pyrenyl group, chrysenyl group, tetracenyl group, furanyl group, thienyl group, pyranyl group, sulfanylpyranyl group, pyrrolyl group, imida Preferred examples include groups with 20 or fewer carbon atoms, such as zoyl groups, oxazolyl groups, thiazoyl groups, pyrazoyl groups, pyridyl groups, isobenzofuranyl groups, benzofuranyl groups, isoclomenyl groups, clomenyl groups, indolyl groups, isoindolyl groups, benzimidazoyl groups, xanthenyl groups, aquadinyl groups, carbazoyl groups, furan groups, thiophene groups, pyrrole groups, imidazole groups, pyran groups, pyridine groups, pyrimidine groups, and pyrazine groups.

[0051] The first substituent described above may further be a group having the first substituent, and this group may further have the first substituent. 11 and R 12 If the alkyl group, etc., has the above-mentioned first substituent, R 11 and R 12 The number of carbon atoms in is preferably 1 to 20, including the number of carbon atoms in the first substituent. When the first substituent has a further first substituent or when the above group has a further first substituent, R 11 and R 12 The number of carbon atoms in R is preferably 1 to 20, including the multiple first substituents. 11 and R 12 R when has a first substituent, and the first substituent has a further first substituent 11 and R 12 Examples include groups having glycol chains or thioglycolate chains.

[0052] R 13 and R14 Each of these groups is independently selected from the group consisting of alkyl groups, hydroxyl groups, mercapto groups, alkylene oxy groups, alkylcarbonyl groups, arylcarbonyl groups, alkylene oxycarbonyl groups, aryloxycarbonyl groups, arylsulfanylcarbonyl groups, arylsulfanyl groups, alkylsulfanyl groups, aryl groups, heteroaryl groups, aryl oxy groups, alkylsulfinyl groups, arylsulfinyl groups, alkylsulfonyl groups, arylsulfonyl groups, (meth)acryloyloxy groups, hydroxy(poly)alkylene oxy groups, amino groups, cyano groups, nitro groups, and halogen atoms, and if carbon is present, the number of carbon atoms is 1 to 12, and these may have substituents.

[0053] One R 14 However, the R is formed via any of the following: direct bonding, methylene group, oxygen atom, sulfur atom, and nitrogen atom-containing group. 14 They may form a heterocyclic structure with the aryl group to which they are bonded.

[0054] R 13 and R 14 Examples of substituents in (hereinafter also referred to as "second substituents") are the same as those for the first substituent described above.

[0055] R 13 and R 14 If the alkyl group, etc., has the second substituent described above, and the onium salt is a low molecular weight compound, then R 13 and R 14 The number of carbon atoms in the atom is preferably 1 to 20, including the carbon atoms of the second substituent.

[0056] R 13 and R 14When the alkyl group is present, at least one of the methylene groups of the alkyl group may be substituted with the above-mentioned divalent heteroatom-containing group. However, it is preferable that there is no continuous linkage of heteroatoms such as -OO-, -SS-, and -OS-. 13 and R 14 Examples include polyalkylene oxy groups such as 2-methoxyethoxy group, 2-ethoxyethoxy group, 2-(2-methoxyethoxy)ethoxy group, 2-(2-ethoxyethoxy)ethoxy group, 2-methoxypropoxy group, and 3-methoxypropoxy group; polyalkylenthio groups such as 2-methylthioethylthio and 2-ethylthioethylthio group; and polyalkylene oxythio groups such as 2-methylthioethoxy group and 2-ethoxyethylthio group. However, some aspects of the present invention are not limited thereto. Preferred R 14 The preferred components are arylsulfanyl groups, alkylsulfanyl groups, amino groups having the first substituent mentioned above, hydroxyl groups, alkoxy groups, etc., because they increase the absorption of the second active energy ray when a ketone derivative is formed, thus providing an efficient source for acid generation. R 14 When R is an arylsulfanyl group, an alkylsulfanyl group, an amino group having the first substituent, a hydroxyl group, or an alkoxy group, 14 The substituents are preferably in the para position relative to the binding site of the acetal or thioacetal moiety. When these substituents are in the para position, the absorption of the second active energy ray tends to increase when a ketone derivative is formed.

[0057] R 15 and R 16 Preferably, each of these is independently selected from the group consisting of: a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, which may have substituents; an aryl group having 6 to 14 carbon atoms, which may have substituents; and a heteroaryl group having 4 to 12 carbon atoms, which may have substituents. The above R 15 and R 16 These atoms may be bonded to each other directly by single bonds, or via any of the groups selected from oxygen atoms, sulfur atoms, and alkylene groups to form a ring structure. The above R 15 and R 16 At least one methylene group in the compound may be substituted with the aforementioned divalent heteroatom-containing group.

[0058] R 15 and R 16 Examples of substituents in this compound are the same as those described in the first substituent above.

[0059] L 2 It is preferable that the group is selected from the group consisting of directly bonded groups; linear, branched, or cyclic alkylene groups having 1 to 12 carbon atoms; alkenylene groups having 2 to 12 carbon atoms; arylene groups having 6 to 14 carbon atoms; heteroarylene groups having 4 to 12 carbon atoms; and groups in which these groups are bonded via an oxygen atom, a sulfur atom, or the nitrogen atom-containing group mentioned above.

[0060] L 3 It is preferable that the group is selected from the group consisting of a direct bond, a methylene group, a sulfur atom, the nitrogen atom-containing group mentioned above, and an oxygen atom.

[0061] Y is either an oxygen atom or a sulfur atom. h is an integer between 1 and 2, and i is an integer between 1 and 3. j is an integer between 0 and 3 when h is 1, and between 0 and 5 when h is 2. k is an integer between 0 and 4 when i is 1, between 0 and 6 when i is 2, and between 0 and 8 when i is 3.

[0062] In some embodiments of the present invention, the onium salt structure in unit A is preferably a monocation. That is, in all cases where h in the above general formula (2) and the above general formula (3) is 1 to 2, the sulfonium cation is preferably a monocation. 2In each of the cases where h is 1 to 2, it replaces any one hydrogen atom on the arylene indicated by the arrows in the general formulas (2-a) to (2-b) below. In the general formula (3) above, L 2 Similarly, in each of the cases where h is 1 to 2, it is replaced by any one hydrogen atom on the arylene indicated by the arrows in the general formulas (3-a) to (3-b) below.

[0063] [ka]

[0064] R 11 , R 12 and R 14 Any one of the hydrogens in R 14 The hydrogen atom on the aryl ring to which is bonded is replaced by the bond with Sp in formula (1) above. In equation (3) above, R 11 ~R 16 , L 2 And Y and each independently correspond to R in equation (2) above. 11 ~R 16 , L 2 The same options are selected for each of Y. h is an integer between 1 and 2, and i is an integer between 1 and 3. j is an integer between 0 and 4 when h is 1, and between 0 and 6 when h is 2. k is an integer between 0 and 5 when i is 1, between 0 and 7 when i is 2, and between 0 and 9 when i is 3. L 4 and L 5 Each of these is independently selected from the group consisting of a direct bond, an alkenylene group with 2 carbon atoms, an alkynylene group with 2 carbon atoms, and a carbonyl group.

[0065] In some embodiments of the present invention, the onium salt structure contained in unit A may include those having the sulfonium cation shown below. The dashed lines in the sulfonium cation shown below indicate the bonding site to Sp in formula (1) above, and if there are multiple dashed lines in the same structure, it is preferable that at least one of them is bonded to Sp. However, some embodiments of the present invention are not limited thereto.

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

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[0072] [ka]

[0073] R 1R is selected from the group consisting of a hydrogen atom; a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched, or cyclic alkenyl group having 2 to 6 carbon atoms. 1 At least one hydrogen atom in the alkyl and alkenyl groups within the above-mentioned group may be substituted with a substituent. 1 Examples of substituents in (hereinafter also referred to as "third substituents") include halogen atoms such as fluorine, chlorine, bromine, or iodine atoms; hydroxyl groups; linear or cyclic alkyl groups having 1 to 12 carbon atoms; alkyl groups containing the above heteroatom-containing group in place of at least one methylene group of the alkyl group; aryl groups; and heteroaryl groups.

[0074] R 1 Examples of linear alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl groups. R 1 Examples of branched alkyl groups having 1 to 6 carbon atoms include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, tert-pentyl group, and others. R 1 Examples of cyclic alkyl groups having 1 to 6 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups.

[0075] R 1 Examples of linear, branched, or cyclic alkenyl groups having 2 to 6 carbon atoms include those in which at least one of the carbon-carbon single bonds of the linear alkyl group, branched alkyl group, and cyclic alkyl group described above is substituted with a carbon-carbon double bond. Also, R 1 The alkyl and alkenyl groups may be fluorinated alkyl groups and fluorinated alkenyl groups in which at least one hydrogen atom in the alkyl and alkenyl groups is substituted with a fluorine atom. Alternatively, all hydrogen atoms may be substituted with the third substituent. A trifluoromethyl group is preferred as the alkyl group.

[0076] L is not particularly limited as long as it can bond the main chain constituting the polymer to the above onium salt structure, but examples include any of the following selected from the group consisting of direct bond, carbonyloxy group, carbonylamino group, phenylenediyl group, naphthalenediyl group, phenylenediyloxy group, naphthalenediyloxy group, phenylenediylcarbonyloxy group, naphthalenediylcarbonyloxy group, phenylenediyloxycarbonyl group, and naphthalenediyloxycarbonyl group. For L, direct bonding or a carbonyloxy group is preferred because it can be easily synthesized.

[0077] Sp is not particularly limited as long as it can act as a spacer between L and the onium salt, but examples include a direct bond; a linear, branched, or cyclic alkylene group having 1 to 6 carbon atoms, which may have substituents; and a linear, branched, or cyclic alkenylene group having 2 to 6 carbon atoms, which may have substituents; and at least one methylene group in Sp may be substituted with the divalent heteroatom-containing group.

[0078] Examples of linear alkylene groups with 1 to 6 carbon atoms in Sp include methylene, ethylene, n-propylene, n-butylene, n-pentylene, and n-hexylene groups. Examples of branched alkylene groups with 1 to 6 carbon atoms in Sp include isopropylene, isobutylene, tert-butylene, isopentylene, and tert-pentylene.

[0079] Examples of cyclic alkylene groups with 1 to 6 carbon atoms in Sp include cyclopropylene, cyclobutylene, cyclopentylene, and cyclohexylene. At least one methylene group in Sp may be substituted with the divalent heteroatom-containing group described above. Note that the number of carbon atoms in the alkylene group of Sp does not include the number of carbon atoms in the substituents that Sp may have.

[0080] Examples of substituents in Sp include those similar to the third substituent described above. Examples of alkyl groups as a third substituent of Sp, and alkyl groups containing the above-mentioned divalent heteroatom-containing group in their backbone, include alkyl groups in which the alkylene group of Sp is monovalent. As the aryl group as the third substituent of sp, the above Ar Sp Similar examples include the above. Examples of heteroaryl groups as the third substituent of Sp include groups having a skeleton such as furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, and pyrazine. Sp may be directly bonded, but a spacer structure is preferred to allow the molecule to move easily, considering that units A can radically recombine with each other and units B can crosslink with each other. Preferably, alkylene groups, alkylene oxy groups, and alkylene carbonyl oxy groups are used.

[0081] The above M + The above R 11 , R 12 Any two or more of the aryl groups to which the sulfonium group is bonded may form a ring structure with the sulfur atom to which they are bonded, either directly by a single bond or via any of the group selected from the group consisting of an oxygen atom, a sulfur atom, the nitrogen atom-containing group and the methylene group, but they are not required to form such a ring structure. + Examples include, but are not limited to, the phenyldibenzothiophenium skeleton, the 10-phenyl-9H-thioxanthene-10-yine skeleton, and the 10-phenylphenoxathiyne-10-ium skeleton.

[0082] X1 - There are no particular restrictions as long as it is a monovalent anion. X1 - The anionic structure may contain organic groups having hydroxyl and sulfanyl groups, but may not contain them. Unit A in one aspect of the present invention is M + It does not have a ring structure such as a phenyldibenzothiophenium skeleton, and the above X1 -It is preferable that the anionic structure is an onium salt structure that does not contain organic groups having hydroxyl and sulfanyl groups.

[0083] X1 - Examples include any of the following selected from the group consisting of alkyl sulfate anions, aryl sulfate anions, alkyl sulfonate anions, aryl sulfonate anions, alkyl carboxylate anions, aryl carboxylate anions, tetrafluoroborate anions, hexafluorophosphonate anions, dialkylsulfonylimid anions, trialkylsulfonatemethide anions, tetrakisphenylborate anions, hexafluoroantimonate anions, monovalent metal oxonium anions, and hydrogenate anions containing these. X1 - At least one hydrogen atom of the alkyl and aryl groups in the compound may be substituted with a fluorine atom. Also, X1 - The alkyl and aryl groups in the compound preferably do not contain hydroxyl or sulfanyl groups as substituents, especially when the cation has a dibenzothiophenium skeleton. As for metallic oxonium anions, NiO2 - and SbO3 - These are some examples. Also, VO4 3- SeO3 2- SeO4 2- MoO4 2- SnO3 2- TeO3 2- TeO4 2- TaO3 2- and WO4 2- For divalent to trivalent substances such as H + It may also be a material in which sulfonium ions, iodonium ions, and 1-2 valent metal cations are appropriately added to make it 1 valent. The 1-2 valent metal cations can be ordinary ones, for example, Na + Sn 2+ Ni 2+ These are some examples.

[0084] Note: X1 -When is a metallic oxonium anion, it is preferable that 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. This is because sensitivity to particle beams and electromagnetic waves is improved. Specifically, SbF6 is an example of a metallic oxonium anion. - SbO3 - Sb(OH)6 - HWO4 - These are some examples of preferred options.

[0085] The anion in Unit A described above is preferably highly hydrophilic in order to improve contrast in photoresist pattern formation. Specifically, examples include alkyl sulfate anions, aryl sulfate anions, alkyl sulfonate anions, aryl sulfonate anions, alkyl carboxylate anions, and aryl carboxylate anions. These anions are preferably free of hydroxyl and sulfanyl groups.

[0086] One aspect of the present invention is that the polymer may contain two or more types of 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 photodecayable base unit A (hereinafter also referred to as "Unit A2"). X1 of the above photodecayable base unit A2 - The photo-decayable base unit A2 is preferably an alkyl carboxylate anion or an aryl carboxylate anion. The photo-decayable base unit A2 is preferably used in combination with the photo-acid generator unit A1. The polymer having unit A2 has the effect of reducing the LWR, making it effective when high resolution is required.

[0087] An onium salt structure containing unit A according to some aspects of the present invention is a structure represented by formulas (2) and (3) above, and has a molar extinction coefficient of 1.0 × 10⁻¹⁰ at 365 nm. 5 cm 2 Preferably less than 1.0 × 10 4 cm 2 It is more preferable that the value be less than / mol. Furthermore, the ketone derivative obtained by deprotecting an onium salt structure acetal or thioacetal contained in Unit A according to some aspects of the present invention has a molar extinction coefficient of 1.0 × 10⁻¹⁰ at 365 nm. 5 cm 2 It is preferable that the amount is 1.0 × 10⁻¹⁶ / mol or more. 6 cm 2 It is more preferable that the value be 1 / mol or higher. The molar extinction coefficient at 365 nm of the above ketone derivative is preferably 5 times or more, more preferably 10 times or more, and even more preferably 20 times or more, than the molar extinction coefficient at 365 nm of the onium salt structure contained in Unit A according to some aspects of the present invention. To achieve the above characteristics, the onium salt represented by formula (2) or (3) above should be used.

[0088] (Method for synthesizing monomers for Unit A) A method for synthesizing a sulfonium salt structure contained in Unit A of a polymer, which is one aspect of the present invention, will be described. The present invention is not limited thereto.

[0089] One example of a synthesis method for unit A of the polymer according to one aspect of the present invention is the synthesis method shown below. First, an arbitrary R 17 Base and R 18 Diphenyl sulfide having a group and optionally R 14Benzoyl chloride containing a group (where i=1 in the following formula) is subjected to a Friedel-Crafts reaction with a Lewis acid to obtain a benzophenone derivative. Next, the sulfide is oxidized to a sulfoxide, and then a benzene containing a hydroxyl group and a Brønsted acid are subjected to a Friedel-Crafts reaction to obtain sulfonium, and an alcohol (R) is obtained using an acid catalyst. 15 The carbonyl group is acetalized using OH). Then, the desired onium salt is obtained using a basic catalyst and (meth)acrylate chloride. In this case, the above R 14 , R 15 , R 17 and R 18 Even substituents other than those exemplified here are R as described above. 14 , R 15 , R 17 and R 18 Within that range, the same result can be obtained.

[0090] [ka]

[0091] As another method for synthesizing unit A of the polymer, which is one aspect of the present invention, for example, the synthesis method shown below can be cited. First, any R 17 Base and R 18 Diphenyl sulfide having a group and optionally R 14 Benzoyl chloride containing a group (i=1 in the formula below) is subjected to a Friedel-Crafts reaction with a Lewis acid to obtain a benzophenone derivative. Next, the sulfide is oxidized to a sulfoxide, and then a benzene containing a hydroxyl group and a Brønsted acid are subjected to a Friedel-Crafts reaction to obtain sulfonium, followed by an alcohol (R) using an acid catalyst. 15 The carbonyl group is acetalized using OH). Then, a sulfonium salt structure is obtained using a Grignard reagent, and the desired sulfonium salt structure is obtained by salt exchange using a salt having the corresponding anion.

[0092] [ka]

[0093] (Unit B) The above-mentioned unit B has a structure that undergoes dehydration by an acid-catalyzed reaction, and is preferably a unit in which a compound represented by the following general formula (I) or (II) is bonded to the Sp group of formula (4) at any position of the compound. The above-mentioned unit B is different from the above-mentioned unit A. The polymer contains a unit B in which at least one of the compounds represented by the following general formula (I) or (II) is bonded to the * portion of formula (4) below at any position in the compound. The inclusion of the above unit B in the polymer makes it possible to improve sensitivity to particle beams or electromagnetic waves. However, the bond to the * portion of formula (4) below excludes the bond at the position of the hydroxyl group in the following general formula (I) or (II).

[0094] [ka]

[0095] In the above general formula (I), R 2 and R 3 Each of these is independently selected from the group consisting of electron-donating groups and electron-withdrawing groups. 2 and R 3 It is preferable that at least one of them is an electron-donating group, as this improves acid reactivity. E is preferably selected from the group consisting of a direct bond; an oxygen atom; a sulfur atom; and a methylene group.

[0096] n 1 n is an integer, either 0 or 1. 4 and n 5 Each of these is an integer between 1 and 2. 4 +n 5 The answer is 2-4. n 4 When n is 1 2 n is an integer between 0 and 4. 4 When n is 2 2is an integer between 0 and 6. n 5 When n is 1 3 n is an integer between 0 and 4. 5 When n is 2 3 is an integer between 0 and 6. n 2 If R is 2 or more 2 When is an electron-donating group or an electron-withdrawing group, two R 2 However, they may form a ring structure with each other either directly by single bonds or via any of the group selected from oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups. n 3 If R is 2 or more 3 When is an electron-donating group or an electron-withdrawing group, two R 3 However, they may form a ring structure with each other either directly by single bonds or via any of the group selected from oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups. In formula (I) above, the divalent nitrogen atom-containing group that forms the ring structure is a group containing a nitrogen atom from among the divalent heteroatom-containing groups.

[0097] In the above general formula (II), R 4 Each of these is independently selected from the group consisting of electron-donating groups and electron-withdrawing groups. 4 At least one of these is the electron-donating group described above, and by using the electron-donating group described above, the acid reactivity is improved. R 5a is selected from the group consisting of a hydrogen atom; a primary alkyl group which may have substituents; and a secondary alkyl group which may have substituents; and the R 5a At least one methylene group may be substituted with a divalent heteroatom-containing group. R 5b is selected from the group consisting of a hydrogen atom; an optionally substituted alkyl group; and an optionally substituted alkenyl group, and the above R 5b At least one methylene group may be substituted with a divalent heteroatom-containing group. Also, R5b is the R 5b A hydroxymethylene group having this property may form a ring structure together with a benzene ring to which it is bonded.

[0098] R 5a The primary or secondary alkyl group can be any alkyl group having a primary or secondary carbon at the bonding site, but linear, branched, or cyclic primary or secondary alkyl groups having 1 to 12 carbon atoms are preferred. Specifically, R 1 Examples of alkyl groups similar to the above include primary and secondary alkyl groups. R 5b Examples of alkyl groups include linear, branched, or cyclic alkyl groups having 1 to 12 carbon atoms. Specifically, R 1 Similar alkyl groups can be listed. R 5b Examples of alkenyl groups include linear, branched, or cyclic alkyl groups having 1 to 12 carbon atoms. Specifically, R 1 Similar alkenyl groups can be listed. R 5a and R 5b The substituents that it has are the above R 1 Examples include those similar to the third substituent possessed by the above-mentioned compound.

[0099] n 6 is an integer from 0 to 7, n 7 n is either 1 or 2. 7 When n is 1, n6 is an integer between 0 and 5. 7 When n is 2 6 The integer is between 0 and 7.

[0100] n 6 If R is 2 or more 4 When is an electron-donating group or an electron-withdrawing group, two R 4 However, they may form a ring structure with each other either directly by single bonds or via any of the group selected from oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups. In the above formula (II), the divalent nitrogen atom-containing group for forming a ring structure includes groups containing a nitrogen atom among the above divalent heteroatom-containing groups.

[0101] Examples of the compound represented by the above general formula (I) or (II) include specifically those shown below.

[0102]

Chemical formula

[0103] In the above unit B, at least any one of the compounds represented by the above general formula (I) or (II) binds to the * part of the following formula (4) at any position of the compound.

[0104]

Chemical formula

[0105] In the above formula (4), R 1 , L and Sp are the same as in the above general formula (1).

[0106] R 2 , R 3 and R 4 Examples of the electron-donating groups of include an alkyl group (-R 13 ); an alkenyl group in which at least one of the carbon-carbon single bonds of the alkyl group (-R 13 ) is substituted with a carbon-carbon double bond; and an alkoxy group (-OR 13 ) and an alkylthio group (-SR 13 ) that are bonded to the ortho position or the para position with respect to the position of the aromatic ring to which the methine carbon to which the hydroxyl group is bonded is bonded; etc.

[0107] The above R 13It is preferable that the alkyl group has one or more carbon atoms. Specific examples of alkyl groups having one or more carbon atoms include, for example, 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-ethylexyl groups; alicyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantane-1-yl, adamantane-2-yl, norbornan-1-yl, and norbornan-2-yl groups; silyl group-substituted alkyl groups in which one of the hydrogen atoms is substituted with a trialkylsilyl group such as trimethylsilyl, triethylsilyl, and dimethylethylsilyl groups; and alkyl groups in which, in the above alkyl groups, at least one of the hydrogen atoms of a carbon atom not directly bonded to the aromatic ring of compound (I) or (II) is substituted with a cyano group or a fluoro group, etc. The above R 13 Preferably, the carbon number is 4 or less.

[0108] R 2 , R 3 and R 4 As for the electron-withdrawing group, -C(=O)R 13a (R 13a );-C(=O)R 13b (R 13b is an aryl group having 6 to 14 carbon atoms, which may have substituents. );-C(=O)OR 13a ;-SO2R 13a ;-SO2R 13b ;Nitro group;-OR substituted at the meta position for nitroso group, trifluoromethyl group, and 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 , -SO2R13a and -SR 13a Examples include groups in which at least one of the carbon-carbon single bonds is replaced by a carbon-carbon double bond or a carbon-carbon triple bond; and so on. R 13a and R 13b The substituents that may be present in the above R 1 Examples include those similar to the third substituent possessed by the above-mentioned compound. R 13a and R 13b If R has substituents, 13a The number of carbon atoms in R is preferably 1 to 12, including the number of carbon atoms in substituents. 13b The number of carbon atoms in the molecule is preferably 6 to 14, including the carbon atoms of the substituents.

[0109] One embodiment of the present invention is a polymer in which either the compound represented by the above general formula (I) or (II) is included in the polymer as unit B, which is bonded to the * portion of formula (4) at any position in the compound. In this case, the position of bond to the * portion of formula (4) is R 2 , R 3 and R 4 Either of the above is preferred. For example, in the case of a compound represented by the general formula (I) above, R 2 It is preferable that one of the H atoms in the polymer has a bonding bond that binds to the * portion of formula (4) above. A polymer according to one aspect of the present invention is R 2 , R 3 and R 4 It is preferable that the carbon atom on the aryl ring to which either of these is bonded is bonded to the * portion of formula (4) above.

[0110] Preferably, as the above unit B, R in formula (4) 1 Examples include a hydrogen atom or a linear alkyl group, where L is a direct bond, a carbonyloxy group, a carbonylamino group, or a phenylenediyl group. Furthermore, in the above unit B, L is a direct bond, a carbonyloxy group, or a carbonylamino group, Sp is a direct bond, and R 1A unit in which the methyl group is a methyl group and the methyl group has at least one of the third substituents, which are a C1-C4 alkyl group, a halogen atom, and an aryl group, is preferred from the viewpoint of LWR. 1 Particularly preferred are ethyl groups, isopropyl groups, butyl groups, methyl halogenated groups (fluoromethyl groups, chloromethyl groups, bromomethyl groups, iodomethyl groups, etc.), and benzyl groups. One aspect of the present invention is that the polymer may contain two or more types of unit B.

[0111] (Unit C) The above-mentioned unit C is an organometallic compound-containing unit having a metal atom selected from the group consisting of Sn, Sb, Ge, Bi, Te, Al, Ni, Zn, Zr, and Hf. The metal atoms contained in the above-mentioned unit C are not particularly limited as long as they have high absorption to first active energy rays such as EUV, and may also be atoms from groups 10 to 16 of the periodic table in addition to the above-mentioned metal atoms. The above-mentioned unit C is preferably a unit in which an alkyl and aryltin, alkyl and arylantimony, alkyl and arylgermane, or alkyl and arylbismutin structure is bonded to the * portion of formula (4) at any position in the structure. The above-mentioned unit C is different from the above-mentioned units A and B. Unit C has a high secondary electron generation efficiency upon irradiation with first active energy rays such as EUV, and can increase the decomposition efficiency of Unit A and optionally included Unit B. There are no particular restrictions on Unit C as long as it contains the metal atoms that absorb first active energy rays such as EUV with high efficiency, but specific examples include the units shown below.

[0112] [ka]

[0113] In the above general formula, R 12aEach of these is preferably independently selected from the group consisting of alkyl groups. 12a The alkyl group may have substituents. Examples of the alkyl groups mentioned above include linear or branched alkyl groups having 1 to 5 carbon atoms, such as methyl group, ethyl group, isopropyl group, n-isopropyl group, sec-butyl group, tert-butyl group, n-butyl group, and pentyl group. The substituents that the alkyl group may have include a hydroxyl group, a sulfonyloxy group, an alkylcarbonyloxy group, an alkyloxycarbonyl group, a cyano group, a methoxy group, an ethoxy group, and the like. In the above formula, two or more R 12a When there exist two R 12a The ring structure may be formed directly by a single bond, or via any of the following selected groups: an oxygen atom, a sulfur atom, the divalent nitrogen atom-containing group, and a methylene group. n 9 n is an integer between 0 and 4. 10 n is an integer from 1 to 5, and n 9 +n 10 n is an integer less than or equal to 5. 10 It is preferable that the value is between 1 and 3.

[0114] In the above general formula, R 12b This is selected from the group consisting of: optionally substituted linear, branched, or cyclic alkyl groups having 1 to 6 carbon atoms; optionally substituted linear, branched, or cyclic alkenyl groups having 2 to 6 carbon atoms; optionally substituted aryl groups having 6 to 14 carbon atoms; and optionally substituted heteroaryl groups having 4 to 12 carbon atoms. R 12b The linear, branched, or cyclic alkyl group is the above R 1 Examples of alkyl groups similar to the above include: R 12b The linear, branched, or cyclic alkenyl group is the above R 1 Examples include those similar to the alkenyl group.

[0115] R 12bAs for the aryl group having 6 to 14 carbon atoms, the above R 11 Examples include those similar to the aryl group in R. 12b As for the heteroaryl group having 4 to 12 carbon atoms, the above R 11 Examples include those similar to the heteroaryl group. Two or more R 12b The ring structure may be formed directly by a single bond, or via any of the following selected groups: an oxygen atom, a sulfur atom, the divalent nitrogen atom-containing group, and a methylene group. Also, the three R's 12b Any two of these may bond with each other to form a ring structure together with the metal atom to which they are bonded. R 12a and R 12b The substituents that may be present in the above R 1 Examples include those similar to the third substituent possessed by the above-mentioned compound.

[0116] Specifically, Unit C includes units composed of monomers containing structures 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. The polymer containing the above-mentioned unit C makes it possible to improve the efficiency of secondary electron generation when irradiated with a first active energy ray such as a particle beam or electromagnetic wave.

[0117] Preferably, as the above unit C, R in formula (4) 1is a hydrogen atom or a linear alkyl group, and examples of L include a direct bond, a carbonyloxy group, or a phenylenediyl group. Also, as the unit C, L is a direct bond, a carbonyloxy group, or a carbonylamino group, Sp is a direct bond, and R 1 is a methyl group, and a unit in which 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 third substituents is preferable from the viewpoint of LWR. R having the above third substituent 1 Particularly preferred examples of R 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, an iodomethyl group, etc.), and a benzyl group. One aspect of the present invention may have two or more of the above unit C in the above polymer.

[0118] (Unit D) The polymer in one aspect of the present invention preferably further contains a unit having an aryloxy group (hereinafter also referred to as "unit D") in addition to the above units A and B to C. As the above unit D, a unit in which a phenol structure is bonded to the * part of the above formula (4) at any position of the structure is preferable. Unit D is not particularly limited as long as it can improve the acid generation efficiency of the acid generated by the above unit A. For example, specific examples include the units shown below.

[0119]

Chemical formula

[0120] In the above general formula, each of R 6 is preferably independently selected from the group consisting of alkyl groups. The alkyl group as R 6 may have a substituent. Examples of the alkyl groups mentioned above include linear or branched alkyl groups having 1 to 5 carbon atoms, such as methyl group, ethyl group, isopropyl group, n-isopropyl group, sec-butyl group, tert-butyl group, n-butyl group, and pentyl group. The substituents that the above alkyl group may have include a cyano group and the above R 1 Examples include those similar to the third substituent possessed by the above-mentioned compound. In the above formula, two or more R 6 When there exist two R 6 The ring structure may be formed directly by a single bond, or via any of the following selected groups: an oxygen atom, a sulfur atom, the divalent nitrogen atom-containing group, and a methylene group. n 8 is an integer between 0 and 4.

[0121] Specifically, examples of Unit D include those composed of monomers such as 4-hydroxyphenyl (meth)acrylate. The polymer containing unit D makes it possible to improve the efficiency of acid generation.

[0122] Preferably, as the above unit D, R in formula (4) 1 Examples include a hydrogen atom or a linear alkyl group, where L is a direct bond, a carbonyloxy group, or a phenylenediyl group. Furthermore, in unit D, L is a direct bond, a carbonyloxy group, or a carbonylamino group, Sp is a direct bond, and R 1 A unit in which the methyl group is a methyl group and the methyl group has at least one of the third substituents, which are a C1-C4 alkyl group, a halogen atom, and an aryl group, is preferred from the viewpoint of LWR. 1 Particularly preferred are ethyl groups, isopropyl groups, butyl groups, methyl halogenated groups (fluoromethyl groups, chloromethyl groups, bromomethyl groups, iodomethyl groups, etc.), and benzyl groups. One aspect of the present invention is that the polymer may contain two or more of the above-mentioned units D.

[0123] (Unit E) In one aspect of the present invention, the polymer preferably further comprises a unit E represented by the following formula (5) having a halogen atom. This unit E is different from the above units A and B to D.

[0124] [ka]

[0125] In the above general formula (5), R 1 , L and Sp are R in the general formula (4) above, respectively. 1 Preferably, the same options as L and Sp are selected. R h This is selected from the group consisting of: a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkylene oxy group having 1 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkenylene oxy group having 2 to 12 carbon atoms, which may have substituents; an aryl group having 6 to 14 carbon atoms, which may have substituents; and a heteroaryl group having 4 to 12 carbon atoms, which may have substituents, and some or all of the hydrogen atoms substituted on the carbon atoms are substituted with fluorine atoms or iodine atoms. It is. R h Examples of alkyl groups, alkenyl groups, alkylene groups of alkylene oxy groups, alkenylene groups of alkenylene oxy groups, aryl groups, and heteroaryl groups are the same as those described in Sp above. Also, R h The substituents are also R 1 Examples include groups similar to the third substituent present in the substituent.

[0126] Specifically, Unit E can be defined as a unit obtained from the monomers listed below.

[0127] [ka]

[0128] Preferably, as the above unit E, R in formula (5) 1 Examples include a hydrogen atom or a linear alkyl group, where L is a direct bond, a carbonyloxy group, a carbonylamino group, or a phenylenediyl group. Furthermore, as unit E, L is a direct bond, a carbonyloxy group, or a carbonylamino group, Sp is a direct bond, and R 1 A unit in which the methyl group is a methyl group and the methyl group has at least one of the third substituents, which are a C1-C4 alkyl group, a halogen atom, and an aryl group, is preferred from the viewpoint of LWR. 1 Particularly preferred are ethyl groups, isopropyl groups, butyl groups, methyl halogenated groups (fluoromethyl groups, chloromethyl groups, bromomethyl groups, iodomethyl groups, etc.), and benzyl groups. One aspect of the present invention is that the polymer may contain two or more of the above-mentioned units E.

[0129] (Other units) In one embodiment of the present invention, the polymer may have units commonly used as a resist composition, in addition to units A and B to E described above, to the extent that the effects of the present invention are not impaired. For example, the asterisk in formula (4) above may be a unit having a skeleton containing an ether group, lactone skeleton, ester group, hydroxyl group, epoxy group, glycidyl group, oxetanyl group, etc. (hereinafter also referred to as "unit F"). Unit F is different from units A and B to E above. Furthermore, a unit having a skeleton with an alcoholic hydroxyl group in the * portion of formula (4) above (hereinafter also referred to as "unit G") is also mentioned. Unit G is different from units A and B to F above. The inclusion of unit G in the polymer tends to increase the proportion of intramolecular crosslinking reactions, which is therefore preferable. Units having a skeleton containing epoxy groups, glycidyl groups, and oxetanyl groups are preferred because cationic polymerization can also occur when a strong acid is used to generate the acid from unit A.

[0130] A polymer in one aspect of the present invention may have a unit H represented by the following general formula (6). Unit H is a different unit from units A and B to G described above. The presence of unit H in a polymer in one aspect of the present invention makes the polymer main chain more susceptible to cleavage by radicals generated by irradiation with particle beams or electromagnetic waves, shortening the polymer chain at the irradiation boundary and reducing the LWR.

[0131] [ka]

[0132] In the above general formula (6), each substituent is preferably as follows: R 10 is selected from the group consisting of linear, branched, or cyclic alkyl groups having 1 to 6 carbon atoms; and linear, branched, or cyclic alkenyl groups having 1 to 6 carbon atoms, and the R 1 In the above alkyl and alkenyl groups, at least one hydrogen atom may be substituted with a substituent, L 10 This is a direct bond, R c R is an aryl group having 6 to 12 carbon atoms, which may have the above-mentioned third substituent. 10 The alkyl groups and alkenyl groups having 1 to 6 carbon atoms are as described above in R 1 The selection is made from the same options as for alkyl groups having 1 to 6 carbon atoms and alkenyl groups having 1 to 6 carbon atoms. Alternatively, R 10 is a methyl group, and the methyl group has at least one of the above third substituents: a C1-C4 alkyl group, a halogen atom, and an aryl group, and L is a direct bond, a carbonyloxy group, or a carbonylamino group, and R cThe alkyl group is a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, which may have a hydrogen atom or the third substituent described above. Furthermore, L is a direct bond, a carbonyloxy group, or a carbonylamino group, and R c R is a hydrogen atom or a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, 10 R is a methyl group, and the methyl group has at least one of the third substituents described above: a C1-C4 alkyl group, a halogen atom, and an aryl group. 10 Particularly preferred are ethyl groups, isopropyl groups, butyl groups, methyl halogenated groups (fluoromethyl groups, chloromethyl groups, bromomethyl groups, iodomethyl groups, etc.), and benzyl groups. Note that unit H is a different unit from units A and B through G.

[0133] The above unit H is derived from monomers such as α-methylstyrene derivatives, 2-ethylacrylic acid and its ester derivatives, 2-benzylacrylic acid and its ester derivatives, 2-propylacrylic acid and its ester derivatives, 2-isopropylacrylic acid and its ester derivatives, 2-butylacrylic acid and its ester derivatives, 2-sec-butylacrylic acid and its ester derivatives, 2-fluoromethylacrylic acid and its ester derivatives, 2-chloromethylacrylic acid and its ester derivatives, 2-bromomethylacrylic acid and its ester derivatives, and 2-iodomethylacrylic acid and its ester derivatives. The following units can be mentioned. Specifically, the above-mentioned unit H can be derived from the monomers listed below.

[0134] [ka]

[0135] A polymer in one aspect of the present invention may have a unit I represented by the following general formula (7).

[0136] [ka]

[0137] In equation (7) above, R 1 , L and Sp are R in the general formula (4) above, respectively. 1 The same options as L and Sp are selected. R d This is selected from: a linear, branched, or cyclic alkylsilyl group having 1 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkyloxysilyl group having 1 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkenylsilyl group having 1 to 12 carbon atoms, which may have substituents; or a linear, branched, or cyclic alkenyloxysilyl group having 1 to 12 carbon atoms, which may have substituents. It may also contain a siloxane bond in which some carbon atoms are substituted with silicon and oxygen atoms, thereby replacing the bonded hydrogen or carbon with oxygen. R d The substituents that may be present in the above R 1 Examples include those similar to the third substituent possessed by the above-mentioned compound. The above-mentioned unit I can enhance the etching resistance of oxygen plasma by containing silicon. Furthermore, when the polymer contains a silane structure as unit I, water is produced when unit B reacts in the presence of an acid catalyst, and this water hydrolyzes unit I to silanol, which forms siloxane bonds and crosslinks, thereby improving sensitivity and substrate adhesion, which is therefore preferable. Note that Unit I is a different unit from Units A and B through H.

[0138] Unit I is, for example, 4-trimethylsilylstyrene, 4-trimethoxysilylstyrene, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, 3-(3,5,7,9,11,13,15-heptisobutylpentacyclic[9,5,1 3,9,1 5,15 ,1 7,13 Octasiloxane-1-yl)propyl methacrylate, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 8-acryloxyoctyltrimethoxysilane, 3-(3,5,7,9,11,13,15-heptisobutylpentacyclic[9,5,1 3,9 ,1 5,15 ,1 7,13 Examples include units derived from monomers such as octasiloxane-1-yl)propyl methacrylate.

[0139] A resist composition in one aspect of the present invention is characterized by undergoing an intramolecular crosslinking reaction upon irradiation with a particle beam or electromagnetic wave. Therefore, it may contain unit J having an onium salt structure other than unit A. Examples of unit J include an onium salt structure consisting of a cation structure other than unit A and an arbitrary anion. The anion is not particularly limited, but examples of cations of unit J are listed below.

[0140] The cation of unit J described above is not particularly limited as long as it has a cationic structure other than that of unit A described above, but a monovalent onium cation is preferred, and it is preferable that one of the atoms selected from the group consisting of sulfur (S) or iodine (I) is an onium cation.

[0141] Examples of onium cations containing a sulfur (S) atom include the sulfonium cation shown in the following general formula (8).

[0142] [ka] In the above equation (8), R a1 ~R a3 These can be independently linear, branched, or cyclic alkyl groups which may have a first substituent, linear, branched, or cyclic alkenyl groups which may have a first substituent, aryl groups which may have a first substituent, and heteroaryl groups which may have a first substituent. R a1 ~R a3 The alkyl group, alkenyl group, aryl group, and heteroaryl group are the above R 11 and R 12 Examples include alkyl groups, alkenyl groups, aryl groups, and heteroaryl groups. Also, R a1 ~R a3 Any two of these may form a ring structure with the sulfur atom to which they are bonded, either directly by a single bond or via any of the group selected from the group consisting of an oxygen atom, a sulfur atom, a divalent nitrogen atom-containing group, and a methylene group. The above-mentioned divalent nitrogen atom-containing groups include those containing a nitrogen atom among the above-mentioned divalent heteroatom-containing groups.

[0143] In the above equation (8), R a1 ~R a3 If the alkyl group is alkyl, the number of carbon atoms is preferably 1 to 15, and more preferably 2 to 10. The above R a1 ~R a3 Examples of linear, branched, or cyclic alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl groups, isopropyl, isobutyl, tert-butyl, isopentyl, tert-pentyl, 2-ethylexyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups.

[0144] In the above equation (8), R a1 ~R a3 If the group is an alkenyl group, the number of carbon atoms is preferably 2 to 15, and more preferably 2 to 10. The above R a1 ~R a3 Examples of linear, branched, or cyclic alkenyl groups include those in which at least one of the carbon-carbon single bonds of the linear alkyl group, branched alkyl group, and cyclic alkyl group described above is substituted with a carbon-carbon double bond. Also, R a1 ~R a3The alkyl and alkenyl groups may be fluorinated alkyl groups and fluorinated alkenyl groups in which at least one hydrogen atom in the alkyl and alkenyl groups is substituted with a fluorine atom. Alternatively, all hydrogen atoms may be substituted with the first substituent. A trifluoromethyl group is preferred as the alkyl group.

[0145] In the above equation (8), R a1 ~R a3 If the group is an aryl group, the number of carbon atoms is preferably 5 to 14, and more preferably 5 to 10.

[0146] In the above equation (8), R a1 ~R a3 When the group is a heteroaryl group, the number of carbon atoms is preferably 3 to 14, and more preferably 3 to 10. The above R a1 ~R a3 Examples of heteroaryl groups include monovalent groups with a skeleton such as furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, pyrazine, indole, purine, quinoline, isoquinoline, chromene, thiantrene, dibenzothiophene, phenothiazine, phenoxazine, xanthene, acridine, phenazine, and carbazole.

[0147] An example of an onium cation containing an iodine (I) atom is the iodonium cation shown in formula (10) below.

[0148] [ka]

[0149] In the above formula, R a4 ~R a5 The above R a1 ~R a3 Similar examples include the above.

[0150] The above unit J binds to the binding site represented by * in formula (4) at either the position of the onium cation shown in the above general formula (8) or (9). One aspect of the present invention is that the polymer may contain two or more of the above-mentioned units J.

[0151] In one embodiment of the present invention, the polymer preferably has a molar ratio of 0.2 to 5 for unit B, 0 to 2 for unit C, 0 to 2 for unit D, 0 to 2 for unit E, 0 to 2 for unit F, 0 to 2 for unit G, 0 to 0.5 for unit H, 0 to 4 for unit I, and 0 to 2 for unit J, with respect to unit A.

[0152] <2> Resist composition A resist composition according to one aspect of the present invention is characterized by containing the above polymer. In addition to the polymers mentioned above, the product may optionally contain other components such as polysubstituted alcohol compounds, organometallic compounds, and organometallic complexes. Each component is described below. The amount of the above polymer in the resist composition is preferably 70 to 100% by mass of the total solid content. (Polysubstituted alcohol compounds) A resist composition according to one aspect of the present invention may contain only the above-mentioned polymer, but may also further contain other components, such as compounds having two or more hydroxyl groups in the molecule, including ethylene glycol, triethylene glycol, erythritol, arabitol, 1,4-benzenedimethanol, and 2,3,5,6-tetrafluoro-1,4-benzenedimethanol. Including these in the resist composition improves the efficiency of the crosslinking reaction and enhances sensitivity to particle beams or electromagnetic waves.

[0153] (Organometallic compounds and organometallic complexes) A resist composition according to one embodiment of the present invention preferably further contains either an organometallic compound or an organometallic complex. The above 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, in order to enhance the sensitization of Unit A and Unit B.

[0154] Examples of the above organometallic compounds 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 above organometallic compound and organometallic complex in the resist composition is preferably 0 to 0.5 molar equivalents relative to unit A.

[0155] (Other ingredients) In any embodiment of the present invention, the resist composition may contain other components as long as the effects of the present invention are not impaired. Possible components include at least one selected from known additives such as fluorine-containing water-repellent polymers, quenchers such as trioctylamine, surfactants, fillers, pigments, antistatic agents, flame retardants, light stabilizers, antioxidants, ion scavengers, and solvents. Examples of the above-mentioned fluorine-containing water-repellent polymer include those commonly used in immersion lithography processes, and it is preferable that they have a higher fluorine atom content than the above-mentioned polymer. As a result, when forming a resist film using the resist composition, the water-repellency 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.

[0156] <3> Method for preparing a resist composition The method for preparing a resist composition according to one embodiment of the present invention is not particularly limited, and it can be prepared by known methods such as mixing, dissolving, or kneading the above-mentioned polymer and other optional components. The above polymer can be synthesized by appropriately polymerizing the monomers constituting the polymer containing unit A, and, if necessary, the monomers constituting other units, using conventional methods. However, the method for producing the polymer according to the present invention is not limited thereto.

[0157] <4> Device manufacturing method One aspect of the present invention is a method for manufacturing a device, comprising the steps of: applying the above-mentioned resist composition onto a substrate to form a resist film; irradiating the resist film with a first active energy ray; irradiating the resist film after irradiation with the first active energy ray with a second active energy ray; and developing the resist film after irradiation with the second active energy ray to obtain a pattern.

[0158] It is preferable that the wavelength of the first activation energy ray is shorter than the wavelength of the second activation energy ray.

[0159] Examples of particle beams or electromagnetic waves used as the first active energy beam for irradiation in the photolithography process include electron beams and EUV beams, respectively. The amount of light irradiation varies depending on the type and proportion of each component in the photocurable composition, as well as the thickness of the coating film, but is approximately 1 J / cm². 2 The following or 1000 μC / cm² 2 The following is preferable:

[0160] The above-mentioned particle beam or electromagnetic wave is preferably an electron beam or extreme ultraviolet light.

[0161] The second active energy ray is preferably ultraviolet light or visible light having a wavelength of 365 nm or longer. The second active energy ray is more preferably 420 nm or shorter. Furthermore, the first active energy ray is preferably higher in energy than the second active energy ray, and is not particularly limited as long as it can generate active species such as acids from the onium salt of unit A.

[0162] Preferably, a heating step is included between the step of irradiating with the first active energy ray and the step of irradiating with the second active energy ray. Examples of heating methods include using an electric heating element or a laser. Furthermore, it is preferable to include a heating step after the step of irradiating with the two active energy rays, and a step of irradiating with the second active energy ray again after the heating step. This tends to increase the amount of decomposition of the ketone derivative generated by the first active energy ray, thereby increasing sensitivity. Furthermore, the process may include a heating step after the step of irradiating with a second active energy ray. This heating step may also include, but is not limited to, heating by an electric heating element or a laser, similar to the heating between the step of irradiating with the first active energy ray and the step of irradiating with the second active energy ray.

[0163] In the pattern formation process, development can be performed using a conventional developer, such as alkaline developers, neutral developers, and organic solvent developers. In addition, water-soluble developers containing water-soluble organic solvents are also preferably used as developers other than those mentioned above. Examples of water-soluble organic solvents include organic compounds having one or more carbon atoms that can be mixed with water in any proportion. Specifically, examples include methanol, ethanol, isopropyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, propylene glycol, propylene glycol monomethyl ether, triethylene glycol, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, diglyme, triglime, acetonitrile, acetone, N,N-dimethylformamide, dimethyl sulfoxide, formic acid, acetic acid, propionic acid, etc.

[0164] The above-mentioned water-soluble developer only needs to be an aqueous solution containing one or more water-soluble organic solvents, and may also contain further insoluble organic solvents. Examples of the above-mentioned insoluble organic solvents include alcohols that are immiscible with water, ethers that are immiscible with water, nitriles that are immiscible with water, ketones that are immiscible with water, esters such as ethyl acetate that are immiscible with water, and organic halogen compounds such as methylene chloride. [Examples]

[0165] Some aspects of the present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples.

[0166] <Synthesis of compound A1 constituting unit A> (Synthesis Example 1) Synthesis of 4-(4-methoxybenzoyl)phenylphenyl sulfide

[0167] [ka]

[0168] Dissolve 4.0 g of phenyl sulfide and 3.6 g of 4-methoxybenzoic acid in 16 g of methanesulfonic acid and bring to 25°C. Add 1.5 g of phosphorus pentoxide and stir at 80°C for 15 hours. Add 60 g of pure water and stir for another 5 minutes, then add 30 g of methylene chloride and stir at room temperature for 2 hours. After separation, wash the resulting organic layer four times with 40 g of pure water. Concentrate the recovered organic layer and allow to dry. Add 20 g of methanol to the obtained solid and wash by dispersion. Filter the solid and dry to obtain 5.5 g of 4-(4-methoxybenzoyl)phenylphenyl sulfide.

[0169] (Synthesis Example 2) Synthesis of 4-(4-methoxybenzoyl)phenylphenyl sulfoxide

[0170] [ka]

[0171] Dissolve 5.5 g of 4-(4-methoxybenzoyl)phenylphenyl sulfide obtained in Synthesis Example 1 above in 17.0 g of formic acid and bring to 35°C. Add 0.88 g of 35% by mass hydrogen peroxide solution dropwise and stir at 25°C for 5 hours. After cooling, add the reaction mixture dropwise to 50 g of pure water to precipitate a solid. Filter off the precipitated solid, wash twice with 20 g of pure water, and then recrystallize using acetone. Filter and dry to obtain 4.6 g of 4-(4-methoxybenzoyl)phenylphenyl sulfoxide.

[0172] (Synthesis Example 3) Synthesis of (4-hydroxyphenyl)[4-(4-methoxybenzoyl)phenyl]phenylsulfonium-iodide

[0173] [ka]

[0174] Dissolve 4.6 g of 4-(4-methoxybenzoyl)phenylphenyl sulfoxide obtained in Synthesis Example 2 above and 1.9 g of phenol in 12 g of methanesulfonic acid and bring to 25°C. Add 1.0 g of phosphorus pentoxide and stir at room temperature for 15 hours. Add 60 g of pure water and stir for another 5 minutes, then wash twice with 20 g of ethyl acetate. Separate the mixture and add 2.5 g of potassium iodide and 30 g of methylene chloride to the resulting aqueous layer and stir at room temperature for 2 hours. Separate the mixture again and wash the resulting organic layer four times with 40 g of pure water. Concentrate the recovered organic layer and add it dropwise to 100 g of diisopropyl ether to precipitate a solid. Filter off the precipitated solid and dry to obtain 5.9 g of (4-hydroxyphenyl)[4-(4-methoxybenzoyl)phenyl]phenylsulfonium-iodide.

[0175] (Synthesis Example 4) Synthesis of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-iodide

[0176] [ka]

[0177] 5.9 g of (4-hydroxyphenyl)[4-(4-methoxybenzoyl)phenyl]phenylsulfonium-iodide obtained in Synthesis Example 3 above and 0.10 g of sulfuric acid are dissolved in 12 g of methanol and heated to 25°C. 2.2 g of trimethyl orthoformate is added dropwise and the mixture is stirred for 3 hours. 0.6 g of triethylamine is added at 30°C and the mixture is stirred for 5 minutes. Then, 35 g of methylene chloride and 50 g of pure water are added to the reaction solution and the mixture is stirred for 10 minutes to recover the organic layer. The obtained organic layer is washed three times with pure water, and the methylene chloride is removed by distillation to obtain 5.4 g of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-iodide.

[0178] (Synthesis Example 5) Synthesis of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-iodide

[0179] [ka]

[0180] Dissolve 2.0 g of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-iodide obtained in Synthesis Example 4 above and 0.4 g of methacrylate chloride in 12 g of methylene chloride and bring to 25°C. Add a solution of 0.3 g of triethylamine dissolved in 1.0 g of methylene chloride dropwise to this and stir at 25°C for 2 hours. After stirring, add 15 g of pure water and stir for another 10 minutes, then separate the liquid and liquid layers. Wash the organic layer twice with 15 g of pure water, concentrate the recovered organic layer, and precipitate a solid by adding it dropwise to 60 g of diisopropyl ether. Filter off the precipitated solid and dry to obtain 2.0 g of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-iodide.

[0181] (Synthesis Example 6) Synthesis of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (Compound A1)

[0182] [ka]

[0183] Dissolve 2.0 g of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-iodide obtained in Synthesis Example 5 above by adding 12 g of methylene chloride. Add 10 g of pure water and 1.1 g of potassium nonafluorobutanesulfonate and stir at 25°C for about 2 hours. Separate the mixture, wash three times with pure water, and then remove the methylene chloride by distillation to obtain 2.3 g of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (compound A1).

[0184] <Synthesis of compound A2, which constitutes unit A> (Synthesis Example 7) Synthesis of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-1,1-difluoro-2-hydroxyethanesulfonate (Compound A2)

[0185] [ka]

[0186] Except for using sodium 1,1-difluoro-2-hydroxysulfonate instead of potassium nonafluorobutanesulfonate, the same procedure as in Synthesis Example 6 was followed to obtain 1.9 g of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-1,1-difluoro-2-hydroxyethanesulfonate (compound A2).

[0187] <Synthesis of compound A3, which constitutes unit A> (Synthesis Example 8) Synthesis of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-4-(3-hydroxyadamantylcarbonyloxy)-1,1,2-trifluorobutanesulfonate (Compound A3)

[0188] [ka]

[0189] In the above Synthesis Example 6, the same procedure as in the above Synthesis Example 6 was carried out, except that sodium 4-(3-hydroxyadamantylcarbonyloxy)-1,1,2-trifluorobutanesulfonate was used instead of potassium nonafluorobutanesulfonate, to obtain 2.6 g of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacrooxyphenyl)phenylsulfonium-4-(3-hydroxyadamantylcarbonyloxy)-1,1,2-trifluorobutanesulfonate (compound A3).

[0190] <Synthesis of compound A4, which constitutes unit A> (Synthesis Example 9) Synthesis of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate

[0191] [ka]

[0192] In the above Synthesis Example 6, the same procedure as in the above Synthesis Example 6 is performed, except that {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-iodide obtained in the above Synthesis Example 5 is replaced with {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-iodide obtained in the above Synthesis Example 4, thereby obtaining 2.0 g of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate.

[0193] (Synthesis Example 10) Synthesis of {4-[dipropioxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate

[0194] [ka]

[0195] In the above Synthesis Example 4, instead of (4-hydroxyphenyl)[4-(4-methoxybenzoyl)phenyl]phenylsulfonium-iodide obtained in the above Synthesis Example 3, {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate obtained in the above Synthesis Example 9 is used, and the same procedure as in the above Synthesis Example 4 is carried out except that methanol is replaced with 1-propanol, thereby obtaining 2.0 g of {4-[dipropioxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate.

[0196] (Synthesis Example 11) Synthesis of {4-[dipropioxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (compound A4)

[0197] [ka]

[0198] In Synthesis Example 5 described above, 1.9 g of {4-[dipropoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (compound A4) is obtained by performing the same procedure as in Synthesis Example 5 described above, except that {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate) obtained in Synthesis Example 10 is used instead of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate) obtained in Synthesis Example 4 described above.

[0199] <Synthesis of compound A5, which constitutes unit A> (Synthesis Example 12) Synthesis of {4-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate

[0200] [ka]

[0201] In the above Synthesis Example 4, the same procedure as in the above Synthesis Example 4 is performed, except that {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate obtained in the above Synthesis Example 9 is used instead of (4-hydroxyphenyl)[4-(4-methoxybenzoyl)phenyl]phenylsulfonium-iodide obtained in the above Synthesis Example 3, and 1,4-butanediol is used instead of methanol, thereby obtaining 2.1 g of {4-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate.

[0202] (Synthesis Example 13) Synthesis of {4-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (Compound A5)

[0203] [ka]

[0204] In the above Synthesis Example 5, the same procedure as in the above Synthesis Example 5 is performed, except that {4-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate obtained in the above Synthesis Example 12 is used instead of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate} obtained in the above Synthesis Example 4 is replaced with {4-[1,3-dioxepan-2-yl-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate} (compound A5).

[0205] <Synthesis of compound A6, which constitutes unit A> (Synthesis Example 14) Synthesis of 9-ethyl-3-(4-fluorobenzoyl)carbazole

[0206] [ka]

[0207] In the above Synthesis Example 1, 5.4 g of 9-ethyl-3-(4-fluorobenzoyl)carbazole is obtained by performing the same procedure as in the above Synthesis Example 1, except that 9-ethylcarbazole is used instead of phenyl sulfide and 4-fluorobenzoic acid is used instead of 4-methoxybenzoic acid.

[0208] (Synthesis Example 15) Synthesis of 9-ethyl-3-(4-phenylsulfanylbenzoyl)carbazole

[0209] [ka]

[0210] 5.0 g of 9-ethyl-3-(4-fluorobenzoyl)carbazole obtained in Synthesis Example 14 above and 2.2 g of benzenethiol are dissolved in 15 g of DMF, then 2.8 g of potassium carbonate is added and the mixture is stirred at 60°C for 1 hour. After returning to room temperature, 40 g of pure water is added and the mixture is extracted with 43 g of ethyl acetate. The organic layer is washed three times with pure water, and the solvent is removed by distillation to obtain crude crystals. Isopropyl ether is added to the crude crystals and the mixture is stirred. The crystals are filtered, collected, and dried to obtain 5.5 g of 9-ethyl-3-(4-phenylsulfanylbenzoyl)carbazole.

[0211] (Synthesis Example 16) Synthesis of 9-ethyl-3-(4-phenylsulfinylbenzoyl)carbazole

[0212] [ka]

[0213] In Synthesis Example 2 described above, 4.6 g of 9-ethyl-3-(4-phenylsulfinylbenzoyl)carbazole is obtained by performing the same procedure as in Synthesis Example 2 described above, except that 9-ethyl-3-(4-phenylsulfinylbenzoyl)carbazole obtained in Synthesis Example 15 is used instead of 4-(4-methoxybenzoyl)phenylphenyl sulfide obtained in Synthesis Example 1 described above.

[0214] (Synthesis Example 17) Synthesis of [4-(9-ethylcarbazole-3-carbonyl)phenyl](4-hydroxyphenyl)phenylsulfonium-iodide

[0215] [ka]

[0216] In the above Synthesis Example 3, the same procedure as in the above Synthesis Example 3 is performed, except that 9-ethyl-3-(4-phenylsulfinylbenzoyl)carbazole obtained in the above Synthesis Example 16 is used instead of 4-(4-methoxybenzoyl)phenylphenyl sulfoxide obtained in the above Synthesis Example 2, thereby obtaining 5.8 g of [4-(9-ethylcarbazole-3-carbonyl)phenyl](4-hydroxyphenyl)phenylsulfonium-iodide.

[0217] (Synthesis Example 18) Synthesis of (4-{dimethoxy-[4-(9-ethylcarbazo-3-yl)phenyl]methyl}phenyl)(4-hydroxyphenyl)phenylsulfonium-iodide

[0218] [ka]

[0219] In the above Synthesis Example 4, the same procedure as in the above Synthesis Example 4 is performed, except that [4-(9-ethylcarbazole-3-carbonyl)phenyl](4-hydroxyphenyl)phenylsulfonium-iodide obtained in the above Synthesis Example 17 is used instead of (4-hydroxyphenyl)[4-(4-methoxybenzoyl)phenyl]phenylsulfonium-iodide obtained in the above Synthesis Example 3, thereby obtaining 5.4 g of (4-{dimethoxy-[4-(9-ethylcarbazo-3-yl)phenyl]methyl}phenyl)(4-hydroxyphenyl)phenylsulfonium-iodide.

[0220] (Synthesis Example 19) Synthesis of (4-{dimethoxy-[4-(9-ethylcarbazo-3-yl)phenyl]methyl}phenyl)(4-methacroxyphenyl)phenylsulfonium-iodide

[0221] [ka]

[0222] In the above Synthesis Example 5, the same procedure as in the above Synthesis Example 5 is performed, except that (4-{dimethoxy-[4-(9-ethylcarbazo-3-yl)phenyl]methyl}phenyl)(4-hydroxyphenyl)phenylsulfonium-iodide obtained in the above Synthesis Example 18 is used instead of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-iodide) obtained in the above Synthesis Example 4, thereby obtaining 2.0 g of (4-{dimethoxy-[4-(9-ethylcarbazo-3-yl)phenyl]methyl}phenyl)(4-methacroxyphenyl)phenylsulfonium-iodide.

[0223] (Synthesis Example 20) Synthesis of (4-{dimethoxy-[4-(9-ethylcarbazo-3-yl)phenyl]methyl}phenyl)(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (Compound A6)

[0224] [ka]

[0225] In the above Synthesis Example 6, the same procedure as in the above Synthesis Example 6 is performed, except that (4-{dimethoxy-[4-(9-ethylcarbazo-3-yl)phenyl]methyl}phenyl)(4-methacroxyphenyl)phenylsulfonium-iodide obtained in the above Synthesis Example 19 is used instead of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}phenyl}methyl}phenyl)(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (compound A6) is obtained by performing the same procedure as in the above Synthesis Example 6, except that (4-{dimethoxy-[4-(9-ethylcarbazo-3-yl)phenyl]methyl}phenyl)(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (compound A6) is used instead of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}phenyl}methyl}phenyl}phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (compound A6) is used instead.

[0226] <Synthesis of compound A7, which constitutes unit A> (Synthesis Example 21) Synthesis of 4-fluoro-4'-phenylsulfanylbenzophenone

[0227] [ka]

[0228] In the above Synthesis Example 1, 5.0 g of 4-fluoro-4'-phenylsulfanylbenzophenone is obtained by performing the same procedure as in the above Synthesis Example 1, except that 4-fluorobenzoic acid is used instead of 4-methoxybenzoic acid.

[0229] (Synthesis Example 22) Synthesis of 4-fluoro-4'-phenylsulfinylbenzophenone

[0230] [ka]

[0231] In Synthesis Example 2 described above, 4.0 g of 4-fluoro-4'-phenylsulfinylbenzophenone is obtained by performing the same procedure as in Synthesis Example 2 described above, except that 4-fluoro-4'-phenylsulfinylbenzophenone obtained in Synthesis Example 21 is used instead of 4-(4-methoxybenzoyl)phenylphenyl sulfide obtained in Synthesis Example 1 described above.

[0232] (Synthesis Example 23) Synthesis of 4-phenylsulfanyl-4'-phenylsulfinylbenzophenone

[0233] [ka]

[0234] In the above synthesis example 15, 4.3 g of 4-phenylsulfanyl-4'-phenylsulfinylbenzophenone is obtained by performing the same procedure as in synthesis example 15, except that 4-fluoro-4'-phenylsulfinylbenzophenone obtained in synthesis example 22 is used instead of 9-ethyl-3-(4-fluorobenzoyl)carbazole obtained in synthesis example 14.

[0235] (Synthesis Example 24) Synthesis of (4-hydroxyphenyl)[4-(4-phenylsulfanylbenzoyl)phenyl]phenylsulfonium-iodide

[0236] [ka]

[0237] In the above Synthesis Example 3, the same procedure as in Synthesis Example 3 is performed, except that 4-phenylsulfanyl-4'-phenylsulfinylbenzophenone obtained in Synthesis Example 23 is used instead of 4-(4-methoxybenzoyl)phenylphenyl sulfoxide obtained in Synthesis Example 2, thereby obtaining 5.5 g of (4-hydroxyphenyl)[4-(4-phenylsulfanylbenzoyl)phenyl]phenylsulfonium-iodide.

[0238] (Synthesis Example 25) Synthesis of {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-iodide

[0239] [ka]

[0240] In the above Synthesis Example 4, the same procedure as in the above Synthesis Example 4 is performed, except that (4-hydroxyphenyl)[4-(4-phenylsulfanylbenzoyl)phenyl]phenylsulfonium-iodide obtained in Synthesis Experiment 24 is used instead of (4-hydroxyphenyl)[4-(4-methoxybenzoyl)phenyl]phenylsulfonium-iodide obtained in the above Synthesis Example 3, thereby obtaining 5.2 g of {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-iodide.

[0241] (Synthesis Example 26) Synthesis of {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-iodide

[0242] [ka]

[0243] In Synthesis Example 5 described above, 2.0 g of {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-iodide is obtained by performing the same procedure as in Synthesis Example 5 described above, except that {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-iodide obtained in Synthesis Example 25 is used instead of {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-iodide.

[0244] (Synthesis Example 27) Synthesis of {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (Compound A7)

[0245] [ka]

[0246] In the above Synthesis Example 6, the same procedure as in the above Synthesis Example 6 is performed, except that {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-iodide obtained in the above Synthesis Example 26 is used instead of {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-iodide obtained in the above Synthesis Example 5, thereby obtaining 2.3 g of {4-[dimethoxy-(4-phenylsulfanylphenyl)methyl]phenyl}(4-methacroxyphenyl)phenylsulfonium-nonafluorobutanesulfonate (compound A7).

[0247] <Synthesis of compound A8, which constitutes unit A> (Synthesis Example 28) Synthesis of diphenyl[4-(4-methoxybenzoyl)phenyl]sulfonium iodide

[0248] [ka]

[0249] In the above Synthesis Example 1, 5.3 g of diphenyl[4-(4-methoxybenzoyl)phenyl]sulfonium-iodide was obtained by performing the same procedure as in Synthesis Example 3, except that benzene was used instead of phenol.

[0250] (Synthesis Example 29) Synthesis of diphenyl[4-(4-hydroxybenzoyl)phenyl]sulfonium-iodide

[0251] [ka]

[0252] 3.0 g of diphenyl[4-(4-methoxybenzoyl)phenyl]sulfonium-iodide obtained in Synthesis Example 28 above was added to 30 ml of acetic acid and heated to 110°C. Then, 2.2 g of 48% by mass aqueous hydrobromic acid solution was added dropwise and the mixture was stirred for 18 hours. After that, the mixture was cooled to 25°C, and 60 ml of pure water and 40 g of methylene chloride were added and the mixture was stirred. After liquid-liquid extraction and washing three times with water, the methylene chloride was removed by distillation to obtain crude crystals. The crude crystals were purified by silica gel column chromatography (methylene chloride / methanol = 80 / 20 (volume ratio)) to obtain 2.5 g of diphenyl[4-(4-hydroxybenzoyl)phenyl]sulfonium-iodide.

[0253] (Synthesis Example 30) Synthesis of {4-[dimethoxy-(4-hydroxyphenyl)methyl]phenyl}diphenylsulfonium-iodide

[0254] [ka]

[0255] In the above Synthesis Example 4, the same procedure as in the above Synthesis Example 4 is performed, except that diphenyl[4-(4-hydroxybenzoyl)phenyl]sulfonium-iodide obtained in the above Synthesis Example 29 is used instead of (4-hydroxyphenyl)[4-(4-methoxybenzoyl)phenyl]phenylsulfonium-iodide obtained in the above Synthesis Example 3, thereby obtaining 2.4 g of {4-[dimethoxy-(4-hydroxyphenyl)methyl]phenyl}diphenylsulfonium-iodide.

[0256] (Synthesis Example 31) Synthesis of {4-[dimethoxy-(4-methacroxyphenyl)methyl]phenyl}diphenylsulfonium-iodide

[0257] [ka]

[0258] In Synthesis Example 5 described above, 2.3 g of {4-[dimethoxy-(4-methchlorooxyphenyl)methyl]phenyl}diphenylsulfonium-iodide is obtained by performing the same procedure as in Synthesis Example 5 described above, except that {4-[dimethoxy-(4-hydroxyphenyl)methyl]phenyl}diphenylsulfonium-iodide obtained in Synthesis Example 30 is used instead of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}diphenylsulfonium-iodide obtained in Synthesis Example 4 described above.

[0259] (Synthesis Example 32) Synthesis of {4-[dimethoxy-(4-methacroxyphenyl)methyl]phenyl}diphenylsulfonium-nonafluorobutanesulfonate (Compound A8)

[0260] [ka]

[0261] In the above Synthesis Example 6, the same procedure as in the above Synthesis Example 6 is performed, except that {4-[dimethoxy-(4-methacroxyphenyl)methyl]phenyl}diphenylsulfonium-iodide obtained in the above Synthesis Example 31 is used instead of {4-[dimethoxy-(4-methacroxyphenyl)methyl]phenyl}diphenylsulfonium-nonafluorobutanesulfonate (compound A8) is obtained by performing the same procedure as in the above Synthesis Example 6, except that {4-[dimethoxy-(4-methacroxyphenyl)methyl]phenyl}diphenylsulfonium-nonafluorobutanesulfonate (compound A8) is used instead of {4-[dimethoxy-(4-methacroxyphenyl)methyl]phenyl}diphenylsulfonium-nonafluorobutanesulfonate (compound A8) is used instead.

[0262] (Synthesis Example 33) Synthesis of (4-{dimethoxy-[4-(3-hydroxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium iodide

[0263] [ka]

[0264] 4.0 g of {4-[dimethoxy-(4-hydroxyphenyl)methyl]phenyl}diphenylsulfonium-iodide obtained in Synthesis Example 30 above and 1.5 g of 3-bromo-1-propanol were dissolved in 30 g of DMF, and then 1.5 g of potassium carbonate was added and the mixture was stirred at 60°C for 3 hours. After returning to room temperature, 40 g of pure water was added and the mixture was extracted with 43 g of ethyl acetate. The organic layer was washed three times with pure water, and the solvent was removed by distillation to obtain crude crystals. Isopropyl ether was added to the crude crystals and stirred, and the crystals were filtered, collected, and dried to obtain 3.5 g of (4-{dimethoxy-[4-(3-hydroxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium-iodide.

[0265] (Synthesis Example 34) Synthesis of (4-{dimethoxy-[4-(3-methacroxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium iodide

[0266] [ka]

[0267] In the above Synthesis Example 5, the same procedure as in the above Synthesis Example 5 is performed, except that (4-{dimethoxy-[4-(3-hydroxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium-iodide obtained in Synthesis Experiment 33 is used instead of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-hydroxyphenyl)phenylsulfonium-iodide) obtained in the above Synthesis Example 4, thereby obtaining 2.0 g of (4-{dimethoxy-[4-(3-methacroxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium-iodide.

[0268] (Synthesis Example 35) Synthesis of (4-{dimethoxy-[4-(3-methacroxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium-nonafluorobutanesulfonate (Compound A9)

[0269] [ka]

[0270] In the above Synthesis Example 6, the same procedure as in the above Synthesis Example 6 is performed, except that (4-{dimethoxy-[4-(3-methacroxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium-iodide obtained in the above Synthesis Example 34 is used instead of {4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl}(4-methacroxyphenyl)methyl}phenyl)diphenylsulfonium-nonafluorobutanesulfonate (compound A9) is obtained by performing the same procedure as in the above Synthesis Example 6, except that (4-{dimethoxy-[4-(3-methacroxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium-nonafluorobutanesulfonate (compound A9) is used instead of {4-[dimethoxy-(4-methacroxypropyl-1-oxy)phenyl]methyl}phenyl)diphenylsulfonium-nonafluorobutanesulfonate (compound A9) is used instead.

[0271] <Synthesis of compound B1, which constitutes unit B> (Synthesis Example 36) Synthesis of 2,4-dimethoxy-4'-hydroxybenzohydrol

[0272] [ka]

[0273] 6.0 g of 2,4-dimethoxy-4'-hydroxybenzophenone is dissolved in 32 g of THF, and 2.2 g of lithium aluminum hydride is added and the mixture is stirred at room temperature for 3 hours. Then, 6 g of pure water is added while checking for hydrogen generation, and the mixture is stirred for another 10 minutes. After adding a 5% by mass aqueous solution of sodium oxalate and stirring for 10 minutes, 30 g of ethyl acetate is added and the mixture is separated. After washing the mixture three times with 10 g of water, the recovered organic layer is concentrated to obtain 5.9 g of 2,4-dimethoxy-4'-hydroxybenzohydrol.

[0274] (Synthesis Example 37) Synthesis of 2,4-dimethoxy-4'-methacrylateoxyhydroxybenzohydrol (compound B1)

[0275] [ka]

[0276] 4.0 g of 2,4-dimethoxy-4'-hydroxybenzohydrol obtained in Synthesis Example 36 above and 4.2 g of methacrylic anhydride are dissolved in 40 g of methylene chloride and brought to 25°C. A solution of 2.8 g of triethylamine dissolved in 7 g of methylene chloride is added dropwise, and the mixture is stirred at 25°C for 2 hours. After stirring, 20 g of pure water is added, and the mixture is stirred for a further 10 minutes before separation. The organic layer is washed twice with 20 g of pure water, and the recovered organic layer is concentrated. The obtained organic layer is purified by column chromatography (ethyl acetate / hexane = 15 / 85 (volume ratio)) after solvent removal, yielding 2.6 g of 2,4-dimethoxy-4'-methacryloxyhydroxybenzohydrol (compound B1).

[0277] <Synthesis of compound B2, which constitutes unit B> (Synthesis Example 38) Synthesis of 4-hydroxybenzohydrol

[0278] [ka]

[0279] In the above synthesis example 36, 3.5 g of 4-hydroxybenzohydrol is obtained by performing the same procedure as in the above synthesis example 36, except that 4-hydroxybenzophenone is used instead of 2,4-dimethoxy-4'-hydroxybenzophenone.

[0280] (Synthesis Example 39) Synthesis of 4-methacryloxyhydroxybenzohydrol (compound B2)

[0281] [ka]

[0282] In the above synthesis example 37, 4-hydroxybenzohydrol obtained in synthesis example 38 was used instead of 2,4-dimethoxy-4'-hydroxybenzohydrol, and the residue obtained by concentration was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)). The same procedure as in the above synthesis example 37 was followed to obtain 3.5 g of 4-methacryloxyhydroxybenzohydrol (compound B2).

[0283] <Synthesis of compound B3, which constitutes unit B> (Synthesis Example 40) Synthesis of 1-(4-hydroxyphenyl)ethanol

[0284] [ka]

[0285] In the above synthesis example 36, 2.7 g of 1-(4-hydroxyphenyl)ethanol is obtained by performing the same procedure as in the above synthesis example 36, except that 4-hydroxyacetophenone is used instead of 2,4-dimethoxy-4'-hydroxybenzophenone.

[0286] (Synthesis Example 41) Synthesis of 1-(4-methacrylateoxyphenyl)ethanol (compound B3)

[0287] [ka]

[0288] In the above synthesis example 37, 2-hydroxybenzhydrol obtained in the above synthesis example 40 was used instead of 2,4-dimethoxy-4'-hydroxybenzhydrol, and the residue obtained by concentration was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)). The same procedure as in the above synthesis example 37 was followed to obtain 3.5 g of 2-methacryloxyhydroxybenzhydrol (compound B3).

[0289] <Synthesis of compound B4, which constitutes unit B> (Synthesis Example 42) Synthesis of 2,4-dimethoxy-4'-(2-vinyloxy)ethoxybenzophenone

[0290] [ka]

[0291] 4.0 g of 2,4-dimethoxy-4'-hydroxybenzophenone, 4.8 g of 2-chloroethyl vinyl ether, and 6.4 g of potassium carbonate are dissolved in 24 g of dimethylformamide. The mixture is stirred at 110°C for 15 hours. The mixture is then cooled to 25°C, 60 g of water is added and the mixture is stirred further. After extraction with 24 g of toluene, the mixture is washed three times with 10 g of water, and the recovered organic layer is concentrated. The resulting organic layer is purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)) after the solvent has been removed, yielding 5.4 g of 2,4-dimethoxy-4'-(2-vinyloxy)ethoxybenzophenone.

[0292] (Synthesis Example 43) Synthesis of 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzophenone

[0293] [ka]

[0294] 5.4 g of 2,4-dimethoxy-4'-(2-vinyloxy)ethoxybenzophenone obtained in Synthesis Example 42 above, 0.42 g of pyridinium-p-toluenesulfonic acid, and 4.2 g of pure water are dissolved in 36 g of acetone. The mixture is stirred at 35°C for 12 hours. After adding 3% by mass aqueous sodium carbonate solution and stirring the mixture further, it is extracted with 42 g of ethyl acetate, and the organic layer is recovered after washing three times with 10 g of water and then concentrated to obtain 4.3 g of 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzophenone.

[0295] (Synthesis Example 44) Synthesis of 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzohydrol

[0296] [ka]

[0297] In the above synthesis example 36, 2.7 g of 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzohydrol is obtained by performing the same procedure as in the above synthesis example 36, except that 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzophenone obtained in the above synthesis example 43 is used instead of 2,4-dimethoxy-4'-hydroxybenzophenone.

[0298] (Synthesis Example 45) Synthesis of 2,4-dimethoxy-4'-(2-methacrylateoxy)ethoxybenzohydrol (Compound B4)

[0299] [ka]

[0300] In the above synthesis example 37, 2,4-dimethoxy-4'-(2-hydroxy)ethoxybenzohydrol obtained in the above synthesis example 44 was used instead of 2,4-dimethoxy-4'-hydroxybenzhydrol, and the residue obtained by concentration was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)), and the same procedure as in the above synthesis example 37 was carried out to obtain 3.5 g of 2,4-dimethoxy-4'-(2-methacrylateoxy)ethoxybenzohydrol (compound B4).

[0301] <Synthesis of compound B5, which constitutes unit B> (Synthesis Example 46) Synthesis of 1-(3-hydroxy-4-methoxyphenyl)methanol

[0302] [ka]

[0303] In the above synthesis example 36, 2.7 g of 1-(4-hydroxyphenyl)methanol is obtained by performing the same procedure as in the above synthesis example 36, except that 3-hydroxy-4-methoxybenzaldehyde is used instead of 2,4-dimethoxy-4'-hydroxybenzophenone.

[0304] (Synthesis Example 47) Synthesis of 1-(3-methacryloxy-4-methoxyphenyl)methanol (compound B5)

[0305] [ka]

[0306] In the above synthesis example 37, 1-(4-hydroxyphenyl)methanol obtained in the above synthesis example 46 was used instead of 2,4-dimethoxy-4'-hydroxybenzhydrol, and the residue obtained by concentration was purified by column chromatography (ethyl acetate / hexane = 10 / 90 (volume ratio)). The same procedure as in the above synthesis example 37 was followed to obtain 2.1 g of 1-(3-methacryloxy-4-methoxyphenyl)methanol (compound B5).

[0307] <Synthesis of compound B6, which constitutes unit B> (Synthesis Example 48) Synthesis of 4-hydroxy-4'-methoxybenzohydrol

[0308] [ka]

[0309] In the above synthesis example 36, 3.5 g of 4-hydroxy-4'-methoxybenzohydrol is obtained by performing the same procedure as in the above synthesis example 36, except that 4-hydroxy-4'-methoxybenzophenone is used instead of 2,4-dimethoxy-4'-hydroxybenzophenone.

[0310] (Synthesis Example 49) Synthesis of 4-methacryloxy-4'-methoxybenzohydrol (compound B6)

[0311] [ka]

[0312] In the above synthesis example 39, 3.5 g of 4-methacryloxy-4'-methoxybenzohydrol (compound B6) is obtained by performing the same procedure as in the above synthesis example 39, except that 4-hydroxybenzohydrol obtained in the above synthesis example 48 is used instead of 4-hydroxybenzohydrol.

[0313] <Synthesis of compound C1, which constitutes unit C> (Synthesis Example 56) Synthesis of 4-vinylphenyl-triphenyltin (compound C1)

[0314] [ka]

[0315] Add 1.2 g of magnesium and 6 g of THF to a flask from which water has been removed. Add a solution of 6.0 g of 4-vinylbromobenzene dissolved in 12.0 g of THF dropwise over 1 hour. After stirring for 1 hour, add the resulting 4-vinylphenylmagnesium bromide solution dropwise over 30 minutes at 5°C to a flask containing 7.3 g of triphenyltin chloride and 36 g of THF, which have been prepared separately. After stirring for 30 minutes, add 600 g of 1% by mass aqueous solution of ammonium chloride and stir for a further 10 minutes. Then, remove the THF by distillation and extract with 60 g of toluene. Separate the solution and wash the resulting organic layer three times with 60 g of pure water. After removing the solvent from the separated organic layer, purify it by column chromatography (ethyl acetate / hexane = 5 / 95 (volume ratio)) to obtain 5.6 g of 4-vinylphenyl-triphenyltin (compound C1).

[0316] <Synthesis of compound C2, which constitutes unit C> (Synthesis Example 57) Synthesis of 4-isopropenylphenyl-triphenyltin (compound C2)

[0317] [ka]

[0318] By performing the same procedure as in Synthesis Example 56 above, except that 4-isopropenylbromobenzene is used instead of 4-vinylbromobenzene, 7.1 g of 4-isopropenylphenyl-triphenyltin (compound C2) is obtained.

[0319] <Synthesis of compound C3, which constitutes unit C> (Synthesis Example 58) Synthesis of 4-vinylphenyl-trimethyltin (compound C3)

[0320] [ka]

[0321] By performing the same procedure as in Synthesis Example 56 above, except that tributyltin chloride is used instead of triphenyltin chloride, 3.1 g of 4-vinylphenyl-tributyltin (compound C3) is obtained.

[0322] <Synthesis of compound C4, which constitutes unit C> (Synthesis Example 58) Synthesis of 3,5-bis(trimethylstannyl)styrene (compound C4)

[0323] [ka]

[0324] By performing the same procedure as in Synthesis Example 56 above, except that tributyltin chloride is used instead of triphenyltin chloride and 3,5-dibromostyrene is used instead of 4-vinylbromobenzene, 4.0 g of 4-vinylphenyl-tributyltin (compound C4) is obtained.

[0325] <Synthesis of compound C5, which constitutes unit C> (Synthesis Example 59) Synthesis of 4-vinylphenyl-triphenylgermane (compound C5)

[0326] [ka]

[0327] By performing the same procedure as in Synthesis Example 56 above, except that triphenylgermanium chloride is used instead of triphenyltin chloride, 3.1 g of 4-vinylphenyl-tributylgermane (compound C5) is obtained.

[0328] <Synthesis of Polymer 1> (Synthesis Example 50) Synthesis of Polymer 1

[0329] [ka]

[0330] 4.0 g of compound A1, 0.8 g of compound A10, 0.71 g of dimethyl-2,2'-azobis(2-methylpropionate) and 0.15 g of α-thioglycerol, which constitute unit A, are dissolved in a mixed solution of 9 g of cyclohexanone and 13 g of γ-butyrolactone and deoxygenated. This is then added dropwise over 4 hours to a mixture of 4 g of γ-butyrolactone and 4 g of cyclohexanone, which has been preheated to 80°C. After addition, the mixture is stirred for 2 hours and then cooled. After cooling, it is reprecipitated by adding it dropwise to 90 g of ethyl acetate. After filtering, the mixture is stirred for 10 minutes in 40 g of 20% by mass methanol aqueous solution, filtered, and vacuum dried to obtain 2.9 g of the target polymer 1. The compound A10 mentioned above is 4-[dimethoxy-(4-methoxyphenyl)methyl]phenyl(4-methacroxyphenyl)phenylsulfonium-salicylate. <Synthesis of Polymer 2> (Synthesis Example 50) Synthesis of Polymer 2

[0331] [ka]

[0332] 3.0 g of compound A1, 1.2 g of compound A10, 1.8 g of compound B1, which constitutes unit A, 0.71 g of dimethyl-2,2'-azobis(2-methylpropionate) and 0.15 g of α-thioglycerol as polymerization initiators are dissolved in a mixed solution of 9 g of cyclohexanone and 13 g of γ-butyrolactone and deoxygenated. This is then added dropwise over 4 hours to a mixed solution of 4 g of γ-butyrolactone and 4 g of cyclohexanone, which has been preheated to 80°C. After addition, the mixture is stirred for 2 hours and then cooled. After cooling, it is reprecipitated by adding it dropwise to 90 g of ethyl acetate. After filtering, the mixture is stirred for 10 minutes in 40 g of 20% by mass methanol aqueous solution, filtered, and vacuum dried to obtain 4.1 g of the target polymer 2.

[0333] <Synthesis of Polymer 3> (Synthesis Example 50) Synthesis of Polymer 3

[0334] [ka]

[0335] 4.0 g of compound A1, which constitutes unit A, 1.5 g of compound C1, which constitutes unit C, and 0.71 g of dimethyl-2,2'-azobis(2-methylpropionate) and 0.15 g of α-thioglycerol as polymerization initiators are dissolved in a mixed solution of 7 g of cyclohexanone and 11 g of γ-butyrolactone, and deoxygenated. This is then added dropwise over 4 hours to a mixture of 4 g of γ-butyrolactone and 4 g of cyclohexanone, which has been preheated to 80°C. After addition, the mixture is stirred for 2 hours and then cooled. After cooling, it is reprecipitated by adding it dropwise to 90 g of ethyl acetate. After filtering, the mixture is stirred for 10 minutes in 40 g of 20% by mass methanol aqueous solution, filtered, and vacuum dried to obtain 3.9 g of the target polymer 2.

[0336] <Synthesis of Polymer 4> (Synthesis Example 50) Synthesis of Polymer 4

[0337] [ka]

[0338] 3.0 g of compound A1 constituting unit A, 1.8 g of compound B1 constituting unit B, 2.1 g of compound C1 constituting unit C, and 0.71 g of dimethyl-2,2'-azobis(2-methylpropionate) and 0.15 g of α-thioglycerol as polymerization initiators are dissolved in a mixed solution of 9 g of cyclohexanone and 13 g of γ-butyrolactone and deoxygenated. This is then added dropwise over 4 hours to a mixture of 4 g of γ-butyrolactone and 4 g of cyclohexanone that has been preheated to 80°C. After addition, the mixture is stirred for 2 hours and then cooled. After cooling, it is reprecipitated by dropwise addition to 90 g of ethyl acetate. After filtering, the mixture is stirred for 10 minutes in 40 g of 20% by mass methanol aqueous solution, filtered, and vacuum dried to obtain 5.3 g of the target polymer 2.

[0339] <Synthesis of polymers 5-8 and comparative polymers 1-4> (Synthesis Example 51) Following the above synthesis example 50, polymers 5 to 8 and comparative polymers 1 to 4 were synthesized using compounds A1, A2, and A6-A7 which constitute unit A, or compounds a1-a2 which constitute comparative unit A, compounds B1, B2, and B4 which constitute unit B, and compounds C1-C3 which constitute unit C. Details of each synthesized polymer are shown in Table 1. Compound a1: (4-methacrylate)phenyldiphenylsulfonium-nonafluorobutanesulfonate (shown below)

[0340] [ka]

[0341] Compound a2: (4-methacrylate)phenyldiphenylsulfonium salicylate (shown below)

[0342] [ka]

[0343] [Table 1]

[0344] <Preparation of the resist composition> 50 mg of any of the polymers listed above (polymers 1-6 and comparative polymers 1-4) was dissolved in a solvent containing cyclohexanone and γ-butyrolactone in a 9:1 ratio to prepare samples 2, 4-6, 8-10 and comparative samples 1, 3, 5, and 7 of the resist compositions in Examples 1-6 and Comparative Examples 1-4. The polymers used in each sample are shown in Tables 2-5.

[0345] <Preparation of Developer> The developing solution was prepared as follows. (1) Using samples 2, 4-6, 8-10 and comparative samples 1, 3, 5, and 7 of the resist composition obtained by dissolving each of the above polymers 1-6 and comparative polymers 1-4, films are prepared by spin coating the compositions to a thickness of 100 nm. (2) Prepare an aqueous solution of acetonitrile with an acetonitrile concentration of 0 to 80% by mass. (3) Each film obtained in (1) above is impregnated with each acetonitrile aqueous solution, and the minimum concentration of acetonitrile in the acetonitrile aqueous solution that completely dissolves the composition applied to the film within 30 seconds is determined. (4) An aqueous acetonitrile solution with a concentration 5% by mass higher than the minimum concentration of acetonitrile determined in (3) above is used as the developer for each sample of the resist composition.

[0346] <Electron beam sensitivity evaluation 1> Comparative sample 1 of the above resist composition is spin-coated onto a silicon wafer. By pre-baking this on a hot plate at 110°C for 1 minute, a substrate with a coated film thickness of 50 nm is obtained. A 50nm line-and-space pattern is drawn on the coated film of the above substrate using an electron beam lithography system (ELS-F100T, manufactured by Elionix Co., Ltd.) with a 125keV electron beam. After electron beam irradiation, the substrate is exposed to 1000mJ / cm² of UV-LED light at 365nm. 2 After irradiating the entire surface with the specified dose, the substrate is post-exposure baked (PEB) on a 90°C hot plate for 1 minute. Then, the substrate is developed for 1 minute using the developer optimized for comparative sample 1 of the resist composition as the patterning developer, and then rinsed with pure water to obtain a 50 nm line and space pattern. The irradiation dose at which a 50 nm (±1 nm) line was obtained was observed using a scanning electron microscope (SEM) (Hitachi High-Tech S-5500). max [μC / cm 2 The sensitivity is determined by electron beam irradiation. The sensitivity of Sample 2 was evaluated in the same manner as that of Comparative Sample 1. The sensitivity of Sample 2 was obtained as relative sensitivity by comparing it to the sensitivity of Comparative Sample 1 (Comparative Example 1), which was used as the baseline. A smaller relative sensitivity value indicates a superior effect. The results are shown in Table 2. Note that while two types of polymer 1 corresponding to Unit A were used, the same sensitivity as Polymer 1 could be obtained with just one type.

[0347] [Table 2]

[0348] The sensitivity of Sample 4 and Comparative Sample 3 were evaluated in the same manner as for Comparative Sample 1. The sensitivity of each sample was obtained as a relative sensitivity by comparing the sensitivity of Sample 4 to that of Comparative Sample 1 (Comparative Example 1), using the latter as the baseline. The results are shown in Table 3.

[0349] [Table 3]

[0350] The sensitivity of sample 6 and comparative sample 5 were evaluated in the same manner as for comparative sample 1. The sensitivity of each sample was obtained as a relative sensitivity by comparing the sensitivity of sample 6 to that of comparative sample 5 (comparative example 3), using the sensitivity of comparative sample 5 as the reference value. The results are shown in Table 4.

[0351] [Table 4]

[0352] The sensitivity of samples 8-10 and comparative sample 7 was evaluated in the same manner as for comparative sample 1. The sensitivity of each sample was obtained as a relative sensitivity by comparing the sensitivity of each sample 8-10 with the sensitivity of comparative sample 7 (comparative example 4) as the reference value. The results are shown in Table 5.

[0353] [Table 5]

[0354] In Examples 1-6, all polymers have an acetal structure on the cation of unit A. This structure allows the polymer to decompose in a catalytic reaction with acid generated by EB irradiation, producing a ketone derivative, which can absorb UV light above 365 nm. Samples containing a polymer according to one aspect of the present invention show improved acid generation efficiency because unit A decomposes and generates acid upon UV irradiation after EB irradiation, resulting in 10-25% higher sensitivity than Comparative Examples 1-4, which have similar unit composition ratios.

[0355] Unit B becomes less soluble in the developer because two molecules are crosslinked by etherification through a dehydration reaction caused by the acid generated by EB irradiation. Therefore, Comparative Example 2, which has Unit B, has relatively higher sensitivity than Example 1. The water produced by the reaction of Unit B enhances the efficiency of Unit A in producing ketone derivatives through acid-catalyzed hydrolysis. Thus, while the sensitivity is 10% higher when comparing Example 1 and Comparative Example 1, Example 2 has more than 20% higher sensitivity than Comparative Example 2 when irradiated with UV.

[0356] Unit C utilizes the Lewis acidity of tin to deactivate the activity of the acid generated by EB irradiation, resulting in better sensitivity than Example 1. Furthermore, it allows for pattern formation without the addition of an acid diffusion control agent, as seen in Examples 1 and 2. The inclusion of metal improves the density of the resist film, thereby increasing the efficiency of secondary electron generation by EB irradiation. Additionally, its high absorption of EUV is expected to similarly improve secondary electron generation efficiency under EUV irradiation. Example 3, which contains Unit C, has high secondary electron generation efficiency and efficiently generates acid, thereby increasing the efficiency of ketone derivative production. As a result, while the sensitivity is 10% higher in Example 1 compared to Comparative Example 1, Example 3 shows 20% higher sensitivity than Comparative Example 3 under UV irradiation.

[0357] Polymers 5 and 6 used in Examples 5 and 6 have unit A derived from compounds A6 and A7, respectively. The ketone derivatives produced by the decomposition of compounds A6 and A7 with acid have higher absorption above 365 nm than the ketone derivative derived from compound A1 used in Example 1. This is because they have arylsulfanil groups or substituted amino groups in the para position of the carbonyl group. As a result, UV absorption is at longer wavelengths, and the decomposition efficiency at 365 nm UV, which is the second active energy ray, tends to be higher, resulting in a sensitivity that is 10-15% higher compared to Example 4.

[0358] <Electron beam sensitivity evaluation 2> A comparative sample 11 of the resist composition described above is spin-coated onto a silicon wafer. By pre-baking this on a hot plate at 110°C for 1 minute, a substrate with a coated film thickness of 50 nm is obtained. A 50nm line-and-space pattern is drawn on the coated film of the above substrate using an electron beam lithography system (ELS-F100T, manufactured by Elionix Co., Ltd.) with a 125keV electron beam. After electron beam irradiation, the substrate is post-exposure baked (PEB) on a 90°C hot plate for 1 minute. Then the substrate is exposed to 1000mJ / cm² of UV-LED light at 365nm. 2 After irradiating the entire surface with the specified irradiation dose, the resist composition was developed for 1 minute using the developer optimized for comparative sample 11 as the patterning developer, and then rinsed with pure water to obtain a 50 nm line and space pattern. The irradiation dose at which the 50 nm line was obtained was observed using a scanning electron microscope (SEM) (Hitachi High-Tech S-5500). max [μC / cm 2 The sensitivity is determined by electron beam irradiation. The sensitivity of sample 12, described below, was evaluated in the same manner as that of comparative sample 11. The sensitivity of sample 12 was obtained as a relative sensitivity by comparing it with the sensitivity of comparative sample 11 (comparative example 5) as the reference value. The results are shown in Table 6.

[0359] [Table 6]

[0360] In one embodiment of the present invention, polymer 4, when heated after irradiation with the first active energy ray, generates ketone derivatives not only from EB irradiation but also from the decomposition of the acetal by an acid-catalyzed reaction due to heating before UV irradiation. Therefore, it can be inferred from the results of Example 7 and Comparative Example 5 that the amount of ketone derivative decomposition tends to increase with subsequent UV irradiation. For this reason, Example 7 has higher relative sensitivity than Comparative Example 5. Furthermore, since Example 7 is heated before UV irradiation, it has higher sensitivity than Example 4, which does not perform heating before UV irradiation.

[0361] <Electron beam sensitivity evaluation 3> A comparative sample 13 of the above resist composition is spin-coated onto a silicon wafer. By pre-baking this on a hot plate at 110°C for 1 minute, a substrate with a coated film thickness of 50 nm is obtained. A 50nm line-and-space pattern is drawn on the coated film of the above substrate using an electron beam lithography system (ELS-F100T, manufactured by Elionix Co., Ltd.) with a 125keV electron beam. Then, the substrate is subjected to a 1000mJ / cm² UV-LED treatment using a 365nm UV-LED. 2 After irradiating the entire surface with the specified dose, the UV-treated substrate is post-exposure baked (PEB) on a 90°C hot plate for 1 minute. Then, the substrate is again exposed to 1000 mJ / cm² of 365 nm UV-LED light. 2 After irradiating the entire surface with the specified irradiation dose, the resist composition was developed for 1 minute using the developer optimized for comparative sample 13 as the patterning developer, and then rinsed with pure water to obtain a 50 nm line and space pattern. The irradiation dose at which the 50 nm line was obtained was observed using a scanning electron microscope (SEM) (Hitachi High-Tech S-5500). max [μC / cm 2 The sensitivity is determined by electron beam irradiation. The sensitivity of sample 14 was evaluated in the same manner as that of comparative sample 13. The sensitivity of sample 14 was obtained as a relative sensitivity by comparing it with the sensitivity of comparative sample 13 (comparative example 6) as the reference value. The results are shown in Table 7.

[0362] [Table 7]

[0363] In one embodiment of the present invention, polymer 4 generates ketone derivatives not only by UV irradiation after the first active energy ray irradiation, but also by the decomposition of the acetal by an acid-catalyzed reaction upon heating after the first UV irradiation. Therefore, it can be inferred from the results of Example 8 and Comparative Example 6 that the ketone derivatives tend to decompose further with a second UV irradiation. For this reason, Example 8 has higher relative sensitivity than Comparative Example 6. Furthermore, since Example 8 involves two UV irradiations and heating before the second UV irradiation, its sensitivity is higher than in both Example 4 and Example 7. [Industrial applicability]

[0364] According to several aspects of the present invention, it is possible to provide a polymer with high absorption efficiency and excellent sensitivity to particle beams or electromagnetic waves such as EUV or electron beams, and a resist composition containing the polymer.

Claims

1. A polymer comprising a unit A having an onium salt structure, wherein the unit A is a unit represented by the following formula (1), 【Chemistry 1】 (In the above general formula (1), R １ R is selected from the group consisting of a hydrogen atom; a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched, or cyclic alkenyl group having 2 to 6 carbon atoms. １ At least one hydrogen atom in the alkyl and alkenyl groups within may be substituted with a substituent. L is selected from the group consisting of a direct bond, a carbonyloxy group, a carbonylamino group, a phenylenediyl group, a naphthalenediyl group, a phenylenediyloxy group, a naphthalenediyloxy group, a phenylenediylcarbonyloxy group, a naphthalenediylcarbonyloxy group, a phenylenediyloxycarbonyl group, and a naphthalenediyloxycarbonyl group. Sp is selected from the group consisting of direct bonds; linear, branched, or cyclic alkylene groups having 1 to 6 carbon atoms, which may have substituents; and linear, branched, or cyclic alkenylene groups having 2 to 6 carbon atoms, which may have substituents, and at least one methylene group in Sp may be substituted with a divalent heteroatom-containing group. X １ － This is one selected from the group consisting of alkyl sulfonate anions, aryl sulfonate anions, alkyl carboxylate anions, and aryl carboxylate anions. In formula (1) above, M １ ＋ However, it can be expressed by the following general formula (3), 【Chemistry 2】 （３） (In formula (3) above, R １１ and R １２ Each of these is an aryl group having 6 to 14 carbon atoms, which may have substituents. The above-mentioned R 1１ , R １２ and any two or more of the aryl groups to which the sulfonium group is bonded may form a ring structure together with the sulfur atom to which they are bonded, either directly by a single bond or 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 aforementioned R 1１ and R １２ At least one methylene group in the compound may be substituted with a divalent heteroatom-containing group. R １３ and R １４ Each of these is independently selected from the group consisting of alkyl groups, hydroxyl groups, mercapto groups, alkylene oxy groups, alkylcarbonyl groups, arylcarbonyl groups, alkylene oxycarbonyl groups, aryloxycarbonyl groups, arylsulfanylcarbonyl groups, alkylsulfanyl groups, aryl groups, heteroaryl groups, aryl oxy groups, alkylsulfinyl groups, arylsulfinyl groups, alkylsulfonyl groups, arylsulfonyl groups, (meth)acryloyloxy groups, hydroxy(poly)alkylene oxy groups, amino groups, cyano groups, nitro groups, and halogen atoms, and if carbon is present, the number of carbon atoms is 1 to 12, and these may have substituents. One R １４ However, the R is formed via any of the following: direct bonding, methylene group, oxygen atom, sulfur atom, and nitrogen atom-containing group. １４ The aryl groups to which they are bonded may form a heterocyclic structure with each other. R １５ and R １６ Each of these is independently a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, which may have substituents; The aforementioned R １５ and R １６ These elements may be bonded to each other directly by single bonds, or via any of the elements selected from the group consisting of oxygen atoms, sulfur atoms, and alkylene groups, to form a ring structure. The aforementioned R １５ and R １６ At least one methylene group in the compound may be substituted with a divalent heteroatom-containing group. L ２ This is one of the groups selected from the following: directly bonded; linear, branched, or cyclic alkylene groups having 1 to 12 carbon atoms; alkenylene groups having 2 to 12 carbon atoms; arylene groups having 6 to 14 carbon atoms; heteroarylene groups having 4 to 12 carbon atoms; and groups in which these groups are bonded via oxygen, sulfur, or nitrogen atom-containing groups. Y is an oxygen atom or a sulfur atom, R 11, R １２ and R １４ Any one of the hydrogens and R １４ The hydrogen atom on the aryl ring to which is bonded is replaced by the bond with Sp in formula (1) above. h is an integer between 1 and 2, i is an integer between 1 and 3. j is an integer between 0 and 4 when h is 1, and between 0 and 6 when h is 2. k is an integer between 0 and 5 when i is 1, between 0 and 7 when i is 2, and between 0 and 9 when i is 3. L ４ and L ５ Each of these is independently selected from the group consisting of a direct bond, a two-carbon alkenylene group, a two-carbon alkynylene group, and a carbonyl group. The polymer further comprises at least one of the following units: Unit B having a structure that undergoes dehydration by an acid-catalyzed reaction; and Unit C containing an organometallic compound having a metal atom. The aforementioned unit B is a unit in which an Sp group of formula (4) is bonded at either position of the compound represented by the following general formula (I) or (II), 【Transformation 3】 （I） 【change】 (II) (In the above general formula (I), R 2 and R 3 These are, independently, electron-donating groups, E is selected from the group consisting of direct bonds; oxygen atoms; sulfur atoms; and methylene groups. n 1 is an integer of 0 or 1, n ４ and n ５ Each of these is an integer between 1 and 2, and n ４ +n ５ The range is 2 to 4, n ４ When n is 1 ２ n is an integer between 0 and 4, and ４ When n is 2 ２ is an integer from 0 to 6, n ５ When n is 1 ３ n is an integer between 0 and 4, and ５ When n is 2 ３ is an integer from 0 to 6, n ２ If it is 2 or more, R 2 When is an electron-donating group or an electron-withdrawing group, two R 2 However, they may form a ring structure with each other either directly by single bonds or via any of the group selected from oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups. n 3 If it is 2 or more, R 3 When is an electron-donating group or an electron-withdrawing group, two R 3 However, they may form a ring structure with each other either directly by single bonds or via any of the following selected groups: oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups. In the above general formula (II), R 4 These are, independently, electron-donating groups, R 5ａ is selected from the group consisting of a hydrogen atom; a primary alkyl group which may have substituents; and a secondary alkyl group which may have substituents, and the R 5ａ At least one methylene group in the compound may be substituted with a divalent heteroatom-containing group. R 5ｂ is selected from the group consisting of a hydrogen atom; an optionally substituted alkyl group; and an optionally substituted alkenyl group, and the R 5ｂ At least one methylene group in the R may be substituted with a divalent heteroatom-containing group, 5ｂ is the R 5ｂ A hydroxymethylene group having this may form a ring structure together with a benzene ring to which it is bonded. n ６ is an integer from 0 to 7, n ７ is 1 or 2, n ７ When n is 1 ６ n is an integer between 0 and 5. ７ When n is 2 ６ is an integer from 0 to 7, n 6 If it is 2 or more, R 4 When is an electron-donating group or an electron-withdrawing group, two R 4 However, they may form a ring structure with each other either directly by single bonds or via any of the groups selected from the group consisting of oxygen atoms, sulfur atoms, divalent nitrogen atom-containing groups, and methylene groups. 【Chemistry 4】 (In formula (4) above, R 1 , L and Sp are R in the general formula (1) above, respectively. 1 (Selected from the same options as L and Sp, * indicates the binding site with the compound represented by the general formula (I) or (II).) A polymer in which the metal in the organometallic compound-containing unit C is Sn or Ge.

2. The polymer according to claim 1, further comprising a unit D represented by the following general formula having an aryloxy group. (In the above general formula, each of R6 is independently an alkyl group, and the alkyl group as R6 may have substituents.) R1 is a hydrogen atom or a linear alkyl group, and L is a direct bond, a carbonyloxy group, or a phenylenediyl group. Sp is selected from the same options as Sp in the general formula (1) above. n is an integer between 0 and 4.

3. The polymer according to claim 1 or 2, further comprising a unit E represented by the following formula (5) having a halogen atom. 【Transformation 5】 (In the above general formula (5), R 1 , L and Sp are R in the general formula (1) above, respectively. 1 , selected from the same options as L and Sp, R ｈ (This is selected from the group consisting of: a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkylene oxy group having 1 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, which may have substituents; a linear, branched, or cyclic alkenylene oxy group having 2 to 12 carbon atoms, which may have substituents; an aryl group having 6 to 14 carbon atoms, which may have substituents; and a heteroaryl group having 4 to 12 carbon atoms, which may have substituents; and some or all of the hydrogen atoms substituted on the carbon atoms are substituted with fluorine atoms or iodine atoms.)

4. A resist composition containing the polymer described in any one of claims 1 to 3.

5. Further containing either an organometallic compound or an organometallic complex, The resist composition according to claim 4, wherein the metal is Ge or Sn.

6. A step of applying the composition according to claim 4 or 5 onto a substrate to form a resist film, The steps include irradiating the resist film with a first active energy ray, The process involves irradiating the resist film after irradiation with the first active energy ray with a second active energy ray, A method for manufacturing a device, comprising the step of developing the resist film after irradiation with the second active energy ray to obtain a pattern.

7. The method for manufacturing the device according to claim 6, wherein the wavelength of the first active energy ray is shorter than the wavelength of the second active energy ray.

8. The method for manufacturing the device according to claim 6 or 7, wherein the first active energy ray is an electron beam or extreme ultraviolet light.

9. A method for manufacturing a device according to any one of claims 6 to 8, comprising a heating step between the step of irradiating with the first active energy ray and the step of irradiating with the second active energy ray.

10. The process of heating after the process of irradiating with the second active energy ray, A method for manufacturing a device according to any one of claims 6 to 9, comprising the step of irradiating the device again with the second active energy ray after the heating step.

11. The first active energy ray irradiation generates a first active species from the composition in the resist film, The first active species causes a structural change in the onium salt structure of unit A, Upon irradiation with the second active energy ray, the second active species is obtained from the structurally altered photoacid generator. A method for manufacturing the device according to any one of claims 6 to 10.

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