WO2024029354A1 - Sulfonium salt and acid generator containing said sulfonium salt - Google Patents

Sulfonium salt and acid generator containing said sulfonium salt Download PDF

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WO2024029354A1
WO2024029354A1 PCT/JP2023/026572 JP2023026572W WO2024029354A1 WO 2024029354 A1 WO2024029354 A1 WO 2024029354A1 JP 2023026572 W JP2023026572 W JP 2023026572W WO 2024029354 A1 WO2024029354 A1 WO 2024029354A1
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group
acid
sulfonium salt
acid generator
reaction
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PCT/JP2023/026572
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French (fr)
Japanese (ja)
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友治 中村
拓人 梶原
智仁 木津
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サンアプロ株式会社
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Publication of WO2024029354A1 publication Critical patent/WO2024029354A1/en

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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C309/00—Sulfonic acids; Halides, esters, or anhydrides thereof
    • C07C309/01—Sulfonic acids
    • C07C309/02—Sulfonic acids having sulfo groups bound to acyclic carbon atoms
    • C07C309/03—Sulfonic acids having sulfo groups bound to acyclic carbon atoms of an acyclic saturated carbon skeleton
    • C07C309/06—Sulfonic acids having sulfo groups bound to acyclic carbon atoms of an acyclic saturated carbon skeleton containing halogen atoms, or nitro or nitroso groups bound to the carbon skeleton
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C311/00—Amides of sulfonic acids, i.e. compounds having singly-bound oxygen atoms of sulfo groups replaced by nitrogen atoms, not being part of nitro or nitroso groups
    • C07C311/48—Amides of sulfonic acids, i.e. compounds having singly-bound oxygen atoms of sulfo groups replaced by nitrogen atoms, not being part of nitro or nitroso groups having nitrogen atoms of sulfonamide groups further bound to another hetero atom
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C381/00—Compounds containing carbon and sulfur and having functional groups not covered by groups C07C301/00 - C07C337/00
    • C07C381/12—Sulfonium compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/004—Photosensitive materials
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/004—Photosensitive materials
    • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/004—Photosensitive materials
    • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists

Definitions

  • the present invention relates to a novel sulfonium salt, an acid generator containing the sulfonium salt, a photoresist containing the sulfonium salt, and a method for manufacturing an electronic device using the photoresist.
  • Photolithography technology is known as a method for achieving higher density and higher integration of semiconductor integrated circuits. By making full use of photolithography technology, it is possible to form fine patterns on semiconductors.
  • photolithography technology first, a chemically amplified resist containing a photoacid generator and a resist is exposed to light, an acid is generated from the photoacid generator, and the solubility of the resist is changed by the acid to form a pattern. . Further, by shortening the wavelength of the exposure light beam, it is possible to advance the miniaturization of the pattern.
  • Triphenylsulfonium salts are known as the photoacid generator (see Patent Document 1).
  • a resist containing a triphenylsulfonium salt can be patterned with high precision by exposure using a KrF excimer laser or an ArF excimer laser.
  • the resist has low sensitivity to light rays having a wavelength of 20 nm or less, such as EUV (extreme ultraviolet), EB (electron beam), and X-rays, making it difficult to use in photolithography using EUV or the like.
  • an object of the present invention is to provide a novel photosensitive compound that rapidly decomposes and generates acid when irradiated with light having a wavelength of 20 nm or less. Another object of the present invention is to provide an acid generator that efficiently generates acid upon irradiation with light having a wavelength of 20 nm or less. Another object of the present invention is to provide a photoresist that can be used in photolithography using light having a wavelength of 20 nm or less. Another object of the present invention is to provide a method for manufacturing an electronic device using the photoresist.
  • the present inventors found that the sulfonium salt represented by the following formula (1) has excellent sensitivity to light with a wavelength of 20 nm or less, and that It was found that by irradiation, it easily decomposes and generates acid (H + X - ) (that is, it has excellent acid generating ability).
  • the present invention was completed based on these findings.
  • the present invention provides a sulfonium salt represented by the following formula (1).
  • Rf 1 , Rf 2 , Rf 11 , and Rf 12 are the same or different and represent a fluorine atom or a fluoroalkyl group.
  • R 1 , R 2 , R 3 , R 11 , R 12 , R 13 , R 21 , R 23 and R 25 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom.
  • R 22 and R 24 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, an iodine atom, a fluorine atom, or represents a fluoroalkyl group .
  • _ _ _ (1 indicates an iodine atom)
  • the present invention also provides the sulfonium salt, wherein the monovalent counteranion is a sulfonic acid anion or a nitrogen anion.
  • the present invention also provides an acid generator containing the sulfonium salt.
  • the present invention also provides a photoresist containing the acid generator and an acid-reactive compound.
  • the present invention also provides a method for manufacturing an electronic device, including a step of forming a pattern by photolithography using the photoresist.
  • the sulfonium salt represented by the above formula (1) (hereinafter sometimes referred to as “sulfonium salt (1)”) has excellent sensitivity to light with a wavelength of 20 nm or less, and By irradiating it, it can be easily decomposed to generate acid (H + X - ). Therefore, by using photoresist containing sulfonium salt (1) and performing photolithography using light beams with a wavelength of 20 nm or less, it is possible to form fine patterns with high precision, further increasing the capacity of electronic devices. Further miniaturization can be achieved.
  • the sulfonium salt (1) of the present invention is a compound represented by the following formula (1).
  • Rf 1 , Rf 2 , Rf 11 , and Rf 12 are the same or different and represent a fluorine atom or a fluoroalkyl group.
  • R 1 , R 2 , R 3 , R 11 , R 12 , R 13 , R 21 , R 23 and R 25 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom.
  • R 22 and R 24 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, an iodine atom, or a fluorine atom. , or a fluoroalkyl group .
  • X - represents a monovalent counter anion. However , at least One represents an iodine atom
  • the alkyl group is, for example, an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a s-butyl group, a t-butyl group, a pentyl group, etc. Examples include linear or branched alkyl groups.
  • the alkyl group is preferably an alkyl group having 1 to 3 carbon atoms, particularly preferably an alkyl group having 1 or 2 carbon atoms, from the viewpoint of easy availability of raw materials.
  • the fluoroalkyl group is a group in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom, and examples of the alkyl group include the same examples as the alkyl group.
  • the fluoroalkyl group is preferably a group in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms, that is, a perfluoroalkyl group (for example, a perfluoro C 1-5 alkyl group).
  • At least _ One represents an iodine atom.
  • compounds in which two or more of the groups selected from the above groups are iodine atoms are preferred because they are easily decomposed by light irradiation to generate acids (that is, they have excellent decomposition efficiency or excellent photosensitivity).
  • compounds in which three or more are iodine atoms are particularly preferred, and compounds in which four or more are iodine atoms are particularly preferred.
  • a compound in which at least one selected from the groups represented by R 1 , R 3 , R 11 , and R 13 is an iodine atom is preferable, and a compound in which two or more are iodine atoms is preferable. More preferred.
  • Examples of the counter anion include a halogen ion, a halogen oxo acid anion, a boron anion, a phosphate anion, a sulfate anion, a sulfonate anion, a nitrogen anion, a carboxylate anion, a methide anion, SbF 6 ⁇ , OH ⁇ , SCN ⁇ , NO 2- , NO3- , etc. are mentioned.
  • halogen ion examples include Cl ⁇ , Br ⁇ , I ⁇ and the like.
  • halogen oxoacid anion examples include ClO 4 - , IO 3 - , BrO 3 -, and the like.
  • boron anions examples include inorganic boron anions such as BF 4 - , (C 6 F 5 ) 4 B - , ((CF 3 ) 2 C 6 H 3 ) 4 B - , tetraphenylborate, and tetrakis(mono).
  • examples include organic boron anions such as fluorophenyl)borate, tetrakis(difluorophenyl)borate, and tetrakis(trifluorophenyl)borate.
  • phosphate anions examples include inorganic phosphate anions such as PF 6 - and PO 4 3- , and (CF 3 CF 2 ) 3 PF 3 - , (CF 3 CF 2 ) 2 PF 4 - and (CF 3 ) .
  • examples include organic phosphate anions such as CF 2 )PF 5 - .
  • the sulfonic acid anion is represented by the following formula (s1), for example.
  • R s1 - SO 3 - (s1) (In the formula, R s1 represents an organic group)
  • Examples of the organic group in R s1 include a C 1-30 hydrocarbon group that may have a substituent, a heterocyclic group that may have a substituent, and two or more of the above groups. Examples include groups connected by a single bond or a linking group selected from -O-, -CO 2 -, -S-, -SO 3 -, and -SO 2 N(R s2 )-.
  • the R s2 represents a hydrogen atom or an alkyl group (for example, a C 1-30 alkyl group).
  • Examples of the substituent include halogen atoms such as fluorine atoms.
  • the C 1-30 hydrocarbon group has a C 1-30 aliphatic hydrocarbon group, a C 3-30 alicyclic hydrocarbon group, a C 6-30 aromatic hydrocarbon group, and two of these are bonded. Contains groups.
  • the C 1-30 hydrocarbon group includes a C 1-30 alkyl group, a C 6-15 aryl group, a C 6-15 cycloalkyl group, a C 6-15 bridged cyclic hydrocarbon group, and two of these. A group to which is bonded is preferable.
  • the heterocyclic group is a group obtained by removing one hydrogen atom from the structural formula of a heterocycle.
  • the heterocycle includes an aromatic heterocycle and a non-aromatic heterocycle.
  • Such a heterocycle includes a 3- to 10-membered ring (preferably a 4- to 6-membered ring) having a carbon atom and at least one type of heteroatom (for example, an oxygen atom, a sulfur atom, a nitrogen atom, etc.) as atoms constituting the ring. ring), and fused rings thereof.
  • sulfonic acid anions include CH 3 SO 3 - , C 4 H 9 SO 3 - , CF 3 SO 3 - , C 2 F 5 C 4 H 4 SO 3 - , C 4 F 9 SO 3 - , Examples include benzenesulfonic acid anion, p-toluenesulfonic acid anion, and camphorsulfonic acid anion.
  • nitrogen anion examples include a sulfonylimide anion represented by the following formula (n1). (R n1 SO 2 ) 2 N - (n1) (In the formula, two R n1s are the same or different and represent an organic group)
  • Examples of the organic group for R n1 include the same examples as the organic group for R s1 .
  • nitrogen anions include (FSO 2 ) 2 N - , (CF 3 SO 2 ) 2 N - , (C 4 F 9 SO 2 ) 2 N - , (C 2 F 5 SO 2 ) 2 N -. etc.
  • the carboxylic acid anion is represented by the following formula (c1), for example.
  • R c1 -COO - (c1) (In the formula, R c1 represents an organic group)
  • Examples of the organic group for R c1 include the same examples as the organic group for R s1 .
  • carboxylic acid anion examples include CF 3 CO 2 - , CH 3 CO 2 - , C 2 H 5 CO 2 - , PhCO 2 -, and the like.
  • methide anion examples include a sulfonyl methide anion represented by the following formula (m1). (R m1 SO 2 ) 3 C - (m1) (In the formula, three R m1 are the same or different and represent an organic group)
  • Examples of the organic group for R m1 include the same examples as the organic group for R s1 .
  • methide anion examples include (CF 3 SO 2 ) 3 C - and the like.
  • the counteranions include, for example, anions described in JP 2013-47211, JP 2021-81708, JP 2013-80245, JP 2013-80240, and JP 2013-33161. .
  • a sulfonic acid anion or a nitrogen anion is preferable from the viewpoint of excellent solubility.
  • the sulfonium salt represented by the above formula (1) can be easily decomposed by light irradiation to generate an acid (that is, has excellent decomposition efficiency or excellent photosensitivity), and is therefore suitable for the following formula (1a).
  • a sulfonium salt represented by the following formula or a sulfonium salt represented by the following formula (1b) is preferable.
  • Rf 31 and Rf 32 are the same or different and represent a fluorine atom or a fluoroalkyl group.
  • R 31 , R 32 and R 33 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom.
  • R 41 , R 42 , R 43 , R 44 and R 45 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom.
  • X ⁇ represents a monovalent counteranion.
  • the two aryl groups shown in parentheses in the above formula (1a) may be the same or different.
  • the three aryl groups shown in parentheses in the above formula (1b) may be the same or different.
  • R 31 , two R 32 , two R 33 , R 41 , R 42 , R 43 , R 44 , and R 45 in formula (1a) is iodine. Indicates an atom. Further, at least one selected from three R 31 , three R 32 , and three R 33 in formula (1b) represents an iodine atom.
  • the sulfonium salt represented by the above formula (1a) the following formula (1a-1 ) is preferred.
  • the sulfonium salt represented by the above formula (1b) can be easily decomposed by light irradiation to generate an acid (that is, has excellent decomposition efficiency or excellent photosensitivity).
  • Sulfonium salts represented by -1) are preferred.
  • Rf 31 and Rf 32 are the same or different and represent a fluorine atom or a fluoroalkyl group.
  • R 31 ′, R 33 ′ , R 41 ′ , R 42 ′ , R 43 ′, R 44 ′, and R 45 ′ are the same or different and represent a hydrogen atom or an iodine atom.
  • X ⁇ represents a monovalent counteranion.
  • the two aryl groups shown in parentheses in the above formula (1a-1) may be the same or different. Further, the three aryl groups shown in parentheses in the above formula (1b-1) may be the same or different.
  • R 31 , two R 33 ′ , R 41 ′ , R 42 ′, R 43 ′, R 44 ′, and R 45 ′ in formula (1a-1). indicates an iodine atom.
  • at least one selected from three R 31 's and three R 33 's in formula (1b-1) represents an iodine atom.
  • Rf 31 and Rf 32 are preferably fluorine atoms because of their particularly excellent decomposition efficiency.
  • R 31 ' and R 33 ' represents an iodine atom because of particularly excellent decomposition efficiency.
  • At least one of the groups represented by R 41 ′ , R 42 ′, R 43 ′, R 44 ′, and R 45 ′ preferably represents an iodine atom, and is selected from the above groups. It is particularly preferred that two or more represent iodine atoms.
  • sulfonium salt represented by the above formula (1a-1) include sulfonium salts represented by the following formulas (1a-1-1) to (1a-1-30).
  • X - is the same as above.
  • sulfonium salt represented by the above formula (1b-1) include sulfonium salts represented by the following formulas (1b-1-1) to (1b-1-12).
  • X - is the same as above.
  • the sulfonium salt (1) has excellent solubility in organic solvents, and the solubility in organic solvents (for example, propylene glycol monomethyl ether acetate) at 25°C is, for example, 2% by weight or more (for example, 2 to 50% by weight). %), preferably 3% by weight or more, more preferably 4% by weight or more, particularly preferably 5% by weight or more.
  • organic solvents for example, propylene glycol monomethyl ether acetate
  • organic solvent examples include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; carbonates such as propylene carbonate, ethylene carbonate, 1,2-butylene carbonate, dimethyl carbonate, and diethyl carbonate; ethyl acetate, butyl acetate, Ethyl lactate, etc., linear or cyclic esters such as ⁇ -propiolactone, ⁇ -butyrolactone, ⁇ -butyrolactone, ⁇ -valerolactone, ⁇ -caprolactone;; ethylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monobutyl ether; Glycol diethers such as dipropylene glycol dimethyl ether, triethylene glycol diethyl ether, tripropylene glycol dibutyl ether; glycol monoethers such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl
  • Ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone can be mentioned. These can be used alone or in combination of two or more.
  • the organic solvent preferably contains at least one selected from ketones, chain esters, and glycol monoether monoesters.
  • the sulfonium salt (1) has high photosensitivity to light having a wavelength of 20 nm or less, such as EUV (extreme ultraviolet), EB (electron beam), and X-rays. Even without using a photosensitizer, simply by irradiating the light beam of the above wavelength , the light energy directly propagates to the sulfonium salt (1), and photodecomposition proceeds rapidly, resulting in acid (H + :X - is the same as above).
  • the sulfonium salt (1) has the above characteristics, it can be suitably used as an acid generator (for example, a photoacid generator).
  • the sulfonium salt represented by formula (1a-1-22) can be produced, for example, by the following reaction.
  • sulfonium salts (1) sulfonium salts other than the sulfonium salt represented by formula (1a-1-22) can also be produced by a method similar to the following reaction.
  • the sulfonium salt represented by formula (1a-1-3) can also be produced, for example, by the following reaction.
  • X - is the same as X - in formula (1) and represents a monovalent counter anion.
  • MX represents a salt of an alkali metal (lithium, sodium, potassium, etc.) cation and a monovalent counter anion.
  • A represents a halogen atom, and X′ ⁇ represents Cl ⁇ or a trifluoromethanesulfonic acid anion.
  • the dehydration condensation reaction can be carried out in the presence or absence of a solvent.
  • a solvent one or more solvents selected from, for example, acetonitrile, ethyl acetate, tetrahydrofuran, chloroform, dichloromethane, etc. can be used.
  • the reaction temperature is about -20 to 150°C, depending on the boiling point of the solvent used.
  • the reaction time is about 1 to several tens of hours.
  • the Grignard reaction can be carried out in the presence or absence of a solvent.
  • a common solvent used in the Grignard reaction for example, one or more solvents selected from diethyl ether, tetrahydrofuran, dichloromethane, etc.
  • the reaction temperature is about -20 to 150°C, depending on the boiling point of the solvent used.
  • the reaction time is about 1 to several tens of hours.
  • the iodination reaction can be carried out using an iodinating agent such as iodine, iodine monochloride, potassium iodide, and N-iodosuccinimide.
  • the iodination reaction can be carried out in the presence or absence of a solvent.
  • a solvent one or more solvents selected from, for example, acetonitrile, ethyl acetate, tetrahydrofuran, chloroform, dichloromethane, etc. can be used.
  • the reaction temperature is, for example, about -20 to 80°C.
  • the reaction time is about 1 to 48 hours.
  • the atmosphere for the above reaction is not particularly limited as long as it does not inhibit the reaction, and may be any of air atmosphere, nitrogen atmosphere, argon atmosphere, etc. Further, the reaction can be carried out by any method such as a batch method, a semi-batch method, or a continuous method.
  • reaction product can be separated and purified by separation means such as filtration, concentration, distillation, extraction, crystallization, adsorption, recrystallization, column chromatography, etc., or a combination of these separation means. .
  • the chemical structure of the sulfonium salt of the present invention is identified by, for example, 1 H-, 11 B-, 13 C-, 19 F-, or 31 P-nuclear magnetic resonance spectrum, infrared absorption spectrum, or elemental analysis). be able to.
  • the acid generator of the present invention contains at least the sulfonium salt (1).
  • the acid generator may contain one type of the sulfonium salt (1) alone, or may contain a combination of two or more types. Further, the acid generator may contain components other than the sulfonium salt (1), but all compounds contained in the acid generator that decompose and generate acid upon irradiation with light (100% by weight %), the proportion of the sulfonium salt (1) is preferably 50% by weight or more, more preferably 60% by weight or more, still more preferably 70% by weight or more, particularly preferably 80% by weight. The content is most preferably 90% by weight or more, particularly preferably 95% by weight or more.
  • the content of the other acid generator should be 100% by weight of all the compounds that decompose and generate acid upon irradiation with light.
  • it is preferably 50% by weight or less, more preferably 40% by weight or less, even more preferably 30% by weight or less, particularly preferably 20% by weight or less, most preferably 10% by weight or less, particularly preferably 5% by weight or less. % by weight or less.
  • the acid generator has excellent solubility in organic solvents, and the amount of the acid generator (or the sulfonium salt (1)) that dissolves in 100 parts by weight of the organic solvent at 25°C is, for example, 5 parts by weight or more, The amount is preferably 10 parts by weight or more, particularly preferably 15 parts by weight or more, and most preferably 20 parts by weight or more.
  • examples of the organic solvent include the same organic solvents in which the sulfonium salt (1) exhibits solubility.
  • the acid generator has excellent sensitivity not only to light rays with longer wavelengths but also to light rays with a wavelength of 20 nm or less, and when irradiated with the light rays, it easily decomposes and generates acid (H + X - ). .
  • the acid generator has the above-mentioned characteristics, it can be suitably used as an acid generator for photoresists (particularly an acid generator for photoresists used in photolithography using light rays with a wavelength of 20 nm or less).
  • the photoresist of the present invention contains the acid generator (or the sulfonium salt (1)) and an acid-reactive compound.
  • the content of the acid generator (or the sulfonium salt (1)) is, for example, 0.001 to 20% by weight, preferably 0.01 to 15% by weight, particularly preferably 0.05% by weight, based on the total amount of acid-reactive compounds. ⁇ 7% by weight.
  • the content of the acid generator (or the sulfonium salt (1)) is 0.001% by weight or more based on the total amount of acid-reactive compounds, it can be used not only for light rays with longer wavelengths but also for light rays with a wavelength of 20 nm or less. It can also exhibit excellent sensitivity. Further, if the content is 20% by weight or less based on the total amount of acid-reactive compounds, the effect of improving the resolution of the photoresist can be obtained.
  • the acid-reactive compound is a compound whose solubility in an alkaline developer changes due to the action of an acid.
  • the photoresist of the present invention may contain one kind of the above-mentioned acid-reactive compounds alone, or may contain two or more kinds in combination.
  • the acid-reactive compounds include compounds that are easily soluble in alkaline developers and react with crosslinking agents in the presence of acids to produce compounds that are poorly soluble or insoluble in alkaline developers; It includes compounds that are soluble or insoluble, and whose solubility in an alkaline developer is increased by the action of an acid.
  • the photoresist includes the following composition (1) and composition (2).
  • Composition (1) Contains the acid generator and a negative photosensitive resin (QN) that is easily soluble in an alkaline developer and produces a compound that is poorly soluble or insoluble in the alkaline developer in the presence of an acid.
  • Composition Composition (2) A composition containing the acid generator and a positive photosensitive resin (QP) that is poorly soluble or insoluble in an alkaline developer and whose solubility in the alkaline developer increases by the action of an acid.
  • Examples of the negative photosensitive resin include a composition containing a phenolic hydroxyl group-containing resin (QN1) and a crosslinking agent (QN2).
  • the phenolic hydroxyl group-containing resin (QN1) is a resin containing a phenolic hydroxyl group that is easily soluble in an alkaline developer, and is a resin that reacts with a crosslinking agent to become poorly soluble or insolubilized in an alkaline developer, such as , novolac resin, polyhydroxystyrene, copolymer of hydroxystyrene, copolymer of hydroxystyrene and styrene, hydroxystyrene, copolymer of styrene and (meth)acrylic acid derivative, phenol-xylylene glycol condensation resin, cresol- Examples include xylylene glycol condensation resin, polyimide containing a phenolic hydroxyl group, polyamic acid containing a phenolic hydroxyl group, and phenol-dicyclopentadiene condensation resin. These can be used alone or in combination of two or more.
  • the phenolic hydroxyl group-containing resin (QN1) may contain a phenolic low molecular compound as a part of the components.
  • the polystyrene equivalent weight average molecular weight (Mw) of the phenolic hydroxyl group-containing resin (QN1) measured by GPC is, for example, 2,000 to 20,000.
  • the crosslinking agent (QN2) is a compound capable of crosslinking the phenolic hydroxyl group-containing resin (QN1) with, for example, an acid generated from an acid generator, and includes, for example, bisphenol A-based epoxy compounds, bisphenol F-based epoxy compounds, bisphenol S-based epoxy compounds, etc.
  • the content of the crosslinking agent (QN2) is determined based on the total acidic functional groups in the phenolic hydroxyl group-containing resin (QN1) from the viewpoint of efficiently making the phenolic hydroxyl group-containing resin (QN1) poorly soluble or insolubilized in an alkaline developer. For example, it is 10 to 40 mol%.
  • Examples of the positive photosensitive resin include an alkali-soluble resin into which an acid-dissociable group is introduced as a protecting group (protecting group-introduced resin; QP1).
  • the protecting group-introduced resin (QP1) is a resin in which some or all of the hydrogen atoms of acidic functional groups (for example, phenolic hydroxyl groups, carboxyl groups, sulfonyl groups, etc.) in an alkali-soluble resin are substituted with acid-dissociable groups.
  • acidic functional groups for example, phenolic hydroxyl groups, carboxyl groups, sulfonyl groups, etc.
  • the protecting group-introduced resin (QP1) itself is insoluble or poorly soluble in an alkaline developer, and when the acid-dissociable group is dissociated by the acid (H + X - ) generated from the acid generator, it becomes easily soluble in the alkaline developer. It changes into an alkali-soluble resin that exhibits properties.
  • the alkali-soluble resin is, for example, a resin with an HLB value of 4 to 19 (preferably 5 to 18, particularly preferably 6 to 17).
  • Alkali-soluble resins include phenolic hydroxyl group-containing resins, carboxyl group-containing resins, and sulfonic acid group-containing resins.
  • phenolic hydroxyl group-containing resin examples include the same resins as the above-mentioned phenolic hydroxyl group-containing resin (QN1).
  • the carboxyl group-containing resin is not particularly limited as long as it is a polymer having a carboxyl group, for example, a homopolymer of a carboxyl group-containing vinyl monomer (Ba), or a carboxyl group-containing vinyl monomer (Ba) and a hydrophobic group-containing vinyl monomer.
  • a homopolymer with (Bb) can be mentioned.
  • carboxyl group-containing vinyl monomer (Ba) is (meth)acrylic acid.
  • hydrophobic group-containing vinyl monomers (Bb) examples include (meth)acrylic acid esters (Bb1) such as C 1-20 alkyl (meth)acrylates and alicyclic group-containing (meth)acrylates, and hydrocarbon monomers having a styrene skeleton.
  • hydrocarbon monomers having a styrene skeleton examples include aromatic hydrocarbon monomers (Bb2) such as vinylnaphthalene.
  • the sulfonic acid group-containing resin is not particularly limited as long as it is a polymer having a sulfonic acid group.
  • a sulfonic acid group-containing vinyl monomer (Bc) such as vinyl sulfonic acid or styrene sulfonic acid, and if necessary, a hydrophobic group-containing vinyl It is obtained by vinyl polymerizing the monomer (Bb).
  • Examples of the acid-dissociable group possessed by the protecting group-introduced resin (QP1) include 1-substituted methyl groups such as methoxymethyl group, benzyl group, and tert-butoxycarbonylmethyl group; 1-methoxyethyl group, 1-ethoxyethyl group; 1-substituted ethyl groups such as; 1-branched alkyl groups such as tert-butyl groups; silyl groups such as trimethylsilyl groups; germyl groups such as trimethylgermyl groups; alkoxycarbonyl groups such as tert-butoxycarbonyl groups; acyl groups; Examples include cyclic acid dissociable groups such as a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, and a tetrahydrothiofuranyl group. These may contain one type alone or a combination of two or more types.
  • Introduction rate of acid-dissociable groups in the protecting group-introduced resin (QP1) [i.e., the number of acid-dissociable groups relative to the total number of unprotected acidic functional groups and acid-dissociable groups in the protecting group-introduced resin (QP1) The ratio] cannot be absolutely defined depending on the acid-dissociable group or the type of alkali-soluble resin into which the group is introduced, but it is preferably 10 to 100%, more preferably 15 to 100%.
  • the polystyrene equivalent weight average molecular weight (Mw) of the protecting group-introduced resin (QP1) measured by GPC is, for example, 1,000 to 150,000, preferably 3,000 to 100,000.
  • the photoresist of the present invention can be prepared, for example, by dissolving the acid generator (or the sulfonium salt (1)) in an organic solvent and mixing this with a photosensitive resin.
  • the photoresist of the present invention may contain one or more other components as necessary.
  • Other components include, for example, organic solvents, pigments, dyes, photosensitizers, dispersants, surfactants, fillers, leveling agents, antifoaming agents, antistatic agents, ultraviolet absorbers, pH adjusters, surface Examples include modifiers, plasticizers, drying accelerators, and the like.
  • the organic solvent may be any solvent that can dissolve the photosensitive resin and impart good coating properties to the photoresist, but among them, those having a boiling point of 200° C. or lower are used. This is preferable in that the photoresist can be easily dried after coating.
  • organic solvents include aromatic hydrocarbons such as toluene; alcohols such as ethanol and methanol; ketones such as cyclohexanone, methyl ethyl ketone, and acetone; esters such as ethyl acetate, butyl acetate, and ethyl lactate; propylene glycol monomethyl ether acetate, etc. Glycol monoether monoesters and the like are preferred. These can be used alone or in combination of two or more.
  • the photoresist of the present invention contains a sulfonium salt (1) that is highly sensitive to light having a wavelength of 20 nm or less. Therefore, even when irradiating with light having a wavelength of 20 nm or less, acid (H + X - ) can be efficiently generated in the exposed area without containing a photosensitizer.
  • the generated acid (H + X - ) changes the solubility of the photosensitive resin in the exposed area in the developer.
  • the photosensitive resin is a negative photosensitive resin, the solubility is reduced by irradiation.
  • the photosensitive resin is a positive photosensitive resin, the solubility increases upon irradiation. Therefore, by using the photoresist of the present invention, an etching mask can be formed with high precision by photolithography.
  • the method for manufacturing an electronic device of the present invention includes a step of forming a pattern by photolithography using the photoresist.
  • the step of forming a pattern by photolithography using the photoresist is preferably a step of forming an etching mask on the substrate through steps 1 to 3 below.
  • Step 1 Forming the photoresist coating film on the substrate
  • Step 2 Irradiating the coating film with light in a pattern
  • Step 3 Performing alkaline development
  • Step 1 This step is a step of forming a coating film of the photoresist on the substrate to be etched.
  • the photoresist coating film can be formed by applying the photoresist onto a substrate using a known method such as spin coating, curtain coating, roll coating, spray coating, or screen printing, and then drying it.
  • Step 2 This step is a step in which the coating film obtained in Step 1 is irradiated with light in a patterned manner, such as by irradiating light through a photomask having a pattern.
  • the light beam used for light irradiation is not particularly limited as long as it can decompose the sulfonium salt (1) and generate a strong acid; Light rays having a wavelength of 20 nm or less, such as X-rays) and X-rays, can also be suitably used.
  • heating at a temperature of 60 to 200°C for about 0.1 to 120 minutes is preferable because it can increase the difference in solubility in an alkaline developer between the exposed and unexposed areas. .
  • Step 3 is a step in which the photoresist coating film that has passed through step 2 is subjected to an alkaline development treatment.
  • alkaline developer used in the alkaline development treatment examples include aqueous sodium hydroxide solution, aqueous potassium hydroxide solution, sodium hydrogen carbonate, and aqueous tetramethylammonium salt solution.
  • Methanol, ethanol, isopropyl alcohol, tetrahydrofuran, N-methylpyrrolidone, etc. may be added to the alkaline developer.
  • the alkaline development treatment is performed by applying the alkaline developer to the coating film by a method such as a dip method, a shower method, or a spray method.
  • the temperature of the alkaline developer is, for example, 25 to 40°C. Further, the alkaline development time is appropriately determined depending on the thickness of the resist, and is, for example, about 1 to 5 minutes.
  • an etching mask can be formed on the substrate. By etching a substrate using the etching mask obtained in this manner, a highly accurate electronic device can be manufactured.
  • the electronic devices include, for example, display devices such as organic EL displays and liquid crystal displays; input devices such as touch panels; light emitting devices; sensor devices; optical scanners, optical switches, acceleration sensors, pressure sensors, gyroscopes, microchannels, This includes MEMS (Micro Electro Mechanical Systems) devices such as inkjet heads.
  • display devices such as organic EL displays and liquid crystal displays
  • input devices such as touch panels
  • sensor devices such as light emitting devices
  • sensor devices optical scanners, optical switches, acceleration sensors, pressure sensors, gyroscopes, microchannels
  • MEMS Micro Electro Mechanical Systems
  • Production example 4 In the same manner as Production Example 3, except that 6.86 g of bis(3,5-difluorophenyl) sulfoxide was changed to 11.9 g of bis(3,5-bistrifluoromethylphenyl) sulfoxide synthesized in Production Example 2. , 1.37 g of [bis(3,5-bistrifluoromethylphenyl)]phenylsulfonium trifluoromethanesulfonate was obtained.
  • the crystals were collected by filtration, dissolved in 30 g of dichloromethane, and 100 g of a 17% dichloromethane solution of boron tribromide was added dropwise within the system temperature within the range of 10°C. After the dropwise addition was completed, the reaction was continued for 1 hour at room temperature to complete the reaction. 50 g of ion-exchanged water was added to the reaction solution, and after neutralization with sodium hydrogen carbonate, the aqueous layer was removed, and the organic layer was further washed three times with 50 g of ion-exchanged water. When the organic layer was removed from the solvent and crystals were precipitated, 150 g of methyl-tert-butyl ether was added to precipitate white crystals. The crystals were collected by filtration and dried under reduced pressure to obtain 5.58 g of [bis(3,5-difluorophenyl)](4-hydroxyphenyl)sulfonium trifluoromethanesulfonate.
  • This solution was added to 80.0 g of ion-exchanged water cooled to 5°C in an ice bath so as not to exceed 15°C, and after the addition was completed, the solution was stirred for 1 hour so as not to exceed 25°C. Then, 60.0 g of toluene was added and stirred for 1 hour. The toluene layer was removed, and the remaining solution was washed twice with 50.0 g of toluene. Thereafter, 30.0 g of dichloromethane was added for extraction, the aqueous layer was separated, and the organic layer was further washed four times with 7.5 g of ion-exchanged water.
  • Example 1 6.53 g of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate synthesized in Production Example 3 was dissolved in 27.9 g of dichloromethane, and 50.6 g of trifluoromethanesulfonic acid was added thereto, followed by N-iodosuccinimide. 3.34 g was added dropwise within the system temperature within the range of not exceeding 5°C. After the addition, the reaction was continued for 1 hour at room temperature to complete the reaction. 36.4 g of ion-exchanged water was added so that the temperature inside the system did not exceed 15° C., and the mixture was stirred for 30 minutes.
  • Example 2 6.86 g of bis(3,5-difluorophenyl) sulfoxide synthesized in Production Example 1 was dissolved in 78.3 g of iodobenzene, and 8.46 g of trifluoromethanesulfonic anhydride was added in a range where the internal temperature of the system did not exceed -5°C. It was dripped. After the dropwise addition was completed, the reaction was continued for 1 hour at room temperature to complete the reaction.
  • the supernatant was removed, and the oily precipitate was added to 50 g of ion-exchanged water at a temperature not exceeding 15° C., then 75 g of tetrahydrofuran and 30 g of toluene were added, and the mixture was stirred for 1 hour.
  • the upper layer was removed, and the remaining solution was washed twice with 30 g portions of toluene. Thereafter, the solution was neutralized with sodium hydrogen carbonate, extracted with 100 g of dichloromethane, the aqueous layer was removed, and the organic layer was further washed three times with 50 g of ion-exchanged water.
  • Example 3 6.53 g of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate synthesized in Production Example 3 was dissolved in 27.9 g of dichloromethane, and 50.6 g of trifluoromethanesulfonic acid was added thereto, followed by N-iodosuccinimide. 10.01 g was added dropwise within the system temperature within the range of not exceeding 5°C. After the addition, the reaction was continued for 10 hours at room temperature to complete the reaction. 36.4 g of ion-exchanged water was added so that the temperature inside the system did not exceed 15° C., and the mixture was stirred for 30 minutes.
  • the upper layer was removed, and the remaining solution was washed twice with 36.4 g of a 5% aqueous sodium thiosulfate solution, and then three times with 36.4 g of ion-exchanged water.
  • the organic layer was desolvented to obtain crude crystals, which were purified by silica gel column chromatography to obtain 7.55 g of sulfonium salts [acid generator (3)], which are salts of cations and anions listed in the table below. Obtained.
  • Example 4 6.53 g of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate synthesized in Production Example 3 was dissolved in 27.9 g of dichloromethane, and 50.6 g of trifluoromethanesulfonic acid was added thereto, followed by N-iodosuccinimide. 13.35 g was added dropwise to the system while the temperature within the system did not exceed 5°C. After the addition, the reaction was continued at room temperature for 20 hours to complete the reaction. 36.4 g of ion-exchanged water was added so that the temperature inside the system did not exceed 15° C., and the mixture was stirred for 30 minutes.
  • Example 5 Instead of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate, 9.22 g of [bis(3,5-bistrifluoromethylphenyl)]phenylsulfonium trifluoromethanesulfonate synthesized in Production Example 4 was used. In the same manner as in Example 1 except for this, 7.10 g of a sulfonium salt [acid generator (5)] which is a salt of a cation and anion listed in the table below was obtained.
  • Example 6 In place of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate, [bis(3,5-difluorophenyl)](2,5-dimethylphenyl)sulfonium trifluoromethanesulfonate 6 synthesized in Production Example 5 5.59 g of a sulfonium salt [acid generator (6)] which is a salt of a cation and anion listed in the table below was obtained in the same manner as in Example 1 except that .91 g was used.
  • Example 7 In place of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate, 6.75 g of [bis(3,5-difluorophenyl)](4-hydroxyphenyl)sulfonium trifluoromethanesulfonate synthesized in Production Example 6. 5.49 g of a sulfonium salt [acid generator (7)], which is a salt of a cation and anion shown in the table below, was obtained in the same manner as in Example 1 except that .
  • Example 8 The same procedure was carried out except that 7.02 g of [tris(3,5-difluorophenyl)]sulfonium trifluoromethanesulfonate synthesized in Production Example 7 was used instead of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate.
  • a sulfonium salt [acid generator (8)] which is a salt of a cation and anion listed in the table below was obtained.
  • Example 9 7.02 g of [tris(3,5-difluorophenyl)]sulfonium trifluoromethanesulfonate synthesized in Production Example 7 was dissolved in 27.9 g of dichloromethane, and after adding 50.6 g of trifluoromethanesulfonic acid, N-iodosuccinimide 6 .67 g was added dropwise within the range where the temperature inside the system did not exceed 5°C. After the addition, the reaction was continued for 10 hours at room temperature to complete the reaction. 36.4 g of ion-exchanged water was added so that the temperature inside the system did not exceed 15° C., and the mixture was stirred for 30 minutes.
  • Example 10 The same procedure was carried out except that 7.02 g of [tris(3,5-difluorophenyl)]sulfonium trifluoromethanesulfonate synthesized in Production Example 7 was used instead of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate.
  • 7.87 g of a sulfonium salt [acid generator (10)] which is a salt of a cation and anion listed in the table below was obtained.
  • Example 11 7.87 g of the sulfonium salt represented by (1-10) synthesized in Example 10 was dissolved in 25.4 g of dichloromethane, poured into 65.2 g of a 5% potassium nonafluorobutanesulfonate aqueous solution, and then heated at 25°C. Stirred for 2 hours. After removing the aqueous layer, the organic layer was washed several times with 23.7 g of ion-exchanged water and dried under reduced pressure. 8.27g was obtained.
  • Example 12 The cations and anions listed in the table below were prepared in the same manner as in Example 11, except that 56.6 g of a 10% bis(nonafluorobutanesulfonyl)imide lithium aqueous solution was used instead of the 5% potassium nonafluorobutanesulfonate aqueous solution. 10.48 g of a sulfonium salt [acid generator (12)] was obtained.
  • the obtained sample solution was placed in a quartz cell with an optical path length of 1 cm, and exposed to an electron beam using an exposure device (JEOL JBX-9300, manufactured by JEOL Ltd.) at an accelerating voltage of 100 kV and an integrated light amount of 50 ⁇ C/cm 2 . exposure was performed.
  • an exposure device JEOL JBX-9300, manufactured by JEOL Ltd.
  • the acid generator in the sample solution decomposes and generates acid due to exposure to light
  • the generated acid reacts with Rhodamine B base and the absorbance at 556 nm increases, so by measuring the absorbance at 556 nm after exposure, The amount of acid generated can be determined.
  • Absorbance was measured using a spectrophotometer (UV-vis).
  • the acid concentration in the sample solution after exposure was determined from the absorbance at 556 nm of the sample solution after exposure using a calibration curve (standard substance: p-toluenesulfonic acid).
  • the acid generation rate was calculated from the following formula, and the photosensitivity was evaluated using the following criteria from the acid generation rate.
  • Acid generation rate (%) acid concentration after exposure (mM) / acid generator concentration before exposure (mM) x 100
  • the acid generator (or sulfonium salt (1)) of the present invention has significantly improved solvent solubility by containing an iodine atom, compared to the case where it does not contain an iodine atom. It can be seen that the photosensitivity to electron beams is improved. As mentioned above, the acid generator (or sulfonium salt (1)) of the present invention has excellent solvent solubility and photosensitivity, so it can be used as an acid generator for photoresists (especially when using light with a wavelength of 20 nm or less).
  • the photoresist containing the acid generator (or sulfonium salt (1)) of the present invention can be suitably used as an acid generator for photoresists used in photolithography (especially for photoresists with a wavelength of 20 nm or less). It can be seen that if photolithography using light beams is performed, fine patterns can be formed with high precision, and electronic devices can be made larger in capacity and smaller in size.
  • the sulfonium salt (1) of the present invention has excellent sensitivity to light with a wavelength of 20 nm or less, and when irradiated with light of the wavelength, it decomposes easily and generates acid (H + X - ). can do. Therefore, if a photoresist containing the sulfonium salt (1) is used and photolithography is performed using a light beam with a wavelength of 20 nm or less, fine patterns can be formed with high precision, which will further increase the capacity of electronic devices. , further miniaturization can be achieved.

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Abstract

Provided is a novel compound that has photosensitivity such that said compound rapidly decomposes and generates an acid when irradiated with light rays having a wavelength of 20 nm or lower.　A sulfonium salt according to the present invention is represented by formula (1). In the formula, Rf1, Rf2, Rf11, and Rf12 are identical to each other or different from each other, each of which represents a fluorine atom or a fluoroalkyl group. R1, R2, R3, R11, R12, R13, R21, R23, and R25 are identical to each other or different from each other, each of which represents a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom. R22 and R24 are identical to each other or different from each other, each of which represents a hydrogen atom, a hydroxyl group, an alkyl group, an iodine atom, a fluorine atom, or a fluoroalkyl group. X- represents a monovalent counter anion. At least one selected from R1, R2, R3, R11, R12, R13, and R21-R25 represents an iodine atom.

Description

スルホニウム塩、及び前記スルホニウム塩を含む酸発生剤Sulfonium salt and acid generator containing the sulfonium salt
　本発明は、新規のスルホニウム塩、前記スルホニウム塩を含む酸発生剤、前記スルホニウム塩を含むフォトレジスト、及び前記フォトレジストを使用した電子デバイスの製造方法に関する。 The present invention relates to a novel sulfonium salt, an acid generator containing the sulfonium salt, a photoresist containing the sulfonium salt, and a method for manufacturing an electronic device using the photoresist.
　電子デバイスは、更なる大容量化、更なる小型化が求められている。そして、これを実現するためには、半導体集積回路をより一層高密度化し、より一層高集積化することが必要である。 Electronic devices are required to have even higher capacity and smaller size. In order to achieve this, it is necessary to further increase the density and integration of semiconductor integrated circuits.
　半導体集積回路の高密度化、高集積化を実現する方法として、フォトリソグラフィー技術が知られている。フォトリソグラフィー技術を駆使すれば、半導体に微細パターンを形成することができる。フォトリソグラフィー技術では、まず、光酸発生剤とレジストを含む化学増幅型レジストに露光を行って、光酸発生剤から酸を発生させ、前記酸によりレジストの溶解性を変化させてパターン形成を行う。そして、露光光線の短波長化により、パターンの微細化を進めることができる。 Photolithography technology is known as a method for achieving higher density and higher integration of semiconductor integrated circuits. By making full use of photolithography technology, it is possible to form fine patterns on semiconductors. In photolithography technology, first, a chemically amplified resist containing a photoacid generator and a resist is exposed to light, an acid is generated from the photoacid generator, and the solubility of the resist is changed by the acid to form a pattern. . Further, by shortening the wavelength of the exposure light beam, it is possible to advance the miniaturization of the pattern.
　前記光酸発生剤としては、トリフェニルスルホニウム塩が知られている（特許文献１参照）。トリフェニルスルホニウム塩を含むレジストは、ＫｒＦエキシマレーザーやＡｒＦエキシマレーザーを用いた露光により、精度良くパターンを加工することができる。しかし、前記レジストは、ＥＵＶ（極紫外線）、ＥＢ（電子線）、Ｘ線などの波長２０ｎｍ以下の光線に対しては感度が低く、ＥＵＶ等を使用したフォトリソグラフィーには使用困難であった。 Triphenylsulfonium salts are known as the photoacid generator (see Patent Document 1). A resist containing a triphenylsulfonium salt can be patterned with high precision by exposure using a KrF excimer laser or an ArF excimer laser. However, the resist has low sensitivity to light rays having a wavelength of 20 nm or less, such as EUV (extreme ultraviolet), EB (electron beam), and X-rays, making it difficult to use in photolithography using EUV or the like.
特開２０１１－１９１７４１号公報JP2011-191741A
　従って、本発明の目的は、波長２０ｎｍ以下の光線を照射すると、速やかに分解して酸を発生する光感応性を有する新規の化合物を提供することにある。
　本発明の他の目的は、波長２０ｎｍ以下の光線照射により効率よく酸を発生する酸発生剤を提供することにある。
　本発明の他の目的は、波長２０ｎｍ以下の光線を利用したフォトリソグラフィーに使用できるフォトレジストを提供することにある。
　本発明の他の目的は、前記フォトレジストを使用した電子デバイスの製造方法を提供することにある。 Therefore, an object of the present invention is to provide a novel photosensitive compound that rapidly decomposes and generates acid when irradiated with light having a wavelength of 20 nm or less.
Another object of the present invention is to provide an acid generator that efficiently generates acid upon irradiation with light having a wavelength of 20 nm or less.
Another object of the present invention is to provide a photoresist that can be used in photolithography using light having a wavelength of 20 nm or less.
Another object of the present invention is to provide a method for manufacturing an electronic device using the photoresist.
　本発明者らは上記課題を解決するため鋭意検討した結果、下記式（１）で表されるスルホニウム塩は、波長２０ｎｍ以下の光線に対して優れた感応性を有し、前記波長の光を照射することで、容易に分解して酸（Ｈ+Ｘ-）を発生すること（つまり、酸発生能に優れること）を見いだした。本発明はこれらの知見に基づいて完成させたものである。 As a result of intensive studies to solve the above problems, the present inventors found that the sulfonium salt represented by the following formula (1) has excellent sensitivity to light with a wavelength of 20 nm or less, and that It was found that by irradiation, it easily decomposes and generates acid (H + X - ) (that is, it has excellent acid generating ability). The present invention was completed based on these findings.
　すなわち、本発明は、下記式（１）で表されるスルホニウム塩を提供する。
Figure JPOXMLDOC01-appb-C000002
 （式中、Ｒｆ1、Ｒｆ2、Ｒｆ11、及びＲｆ12は同一又は異なってフッ素原子又はフルオロアルキル基を示す。Ｒ1、Ｒ2、Ｒ3、Ｒ11、Ｒ12、Ｒ13、Ｒ21、Ｒ23、及びＲ25は同一又は異なって水素原子、水酸基、アルキル基、又はヨウ素原子を示す。Ｒ22、Ｒ24は同一又は異なって水素原子、水酸基、アルキル基、ヨウ素原子、フッ素原子、又はフルオロアルキル基を示す。Ｘ-は１価の対アニオンを示す。但し、Ｒ1、Ｒ2、Ｒ3、Ｒ11、Ｒ12、Ｒ13、及びＲ21～Ｒ25から選択される少なくとも１つはヨウ素原子を示す） That is, the present invention provides a sulfonium salt represented by the following formula (1).
Figure JPOXMLDOC01-appb-C000002
 (In the formula, Rf 1 , Rf 2 , Rf 11 , and Rf 12 are the same or different and represent a fluorine atom or a fluoroalkyl group. R 1 , R 2 , R 3 , R 11 , R 12 , R 13 , R 21 , R 23 and R 25 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom. R 22 and R 24 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, an iodine atom, a fluorine atom, or represents a fluoroalkyl group . _ _ _ (1 indicates an iodine atom)
　本発明は、また、前記１価の対アニオンが、スルホン酸アニオン又は窒素アニオンである前記スルホニウム塩を提供する。 The present invention also provides the sulfonium salt, wherein the monovalent counteranion is a sulfonic acid anion or a nitrogen anion.
　本発明は、また、前記スルホニウム塩を含む酸発生剤を提供する。 The present invention also provides an acid generator containing the sulfonium salt.
　本発明は、また、前記酸発生剤と酸反応性化合物を含むフォトレジストを提供する。 The present invention also provides a photoresist containing the acid generator and an acid-reactive compound.
　本発明は、また、前記フォトレジストを使用したフォトリソグラフィーによりパターン形成を行う工程を含む、電子デバイスの製造方法を提供する。 The present invention also provides a method for manufacturing an electronic device, including a step of forming a pattern by photolithography using the photoresist.
　上記式（１）で表されるスルホニウム塩（以後、「スルホニウム塩（１）」と称する場合がある）は、波長２０ｎｍ以下の光線に対して優れた感応性を有し、前記波長の光を照射することで、容易に分解して酸（Ｈ+Ｘ-）を発生することができる。そのため、スルホニウム塩（１）を含むフォトレジストを用いて、波長２０ｎｍ以下の光線を使用したフォトリソグラフィーを行えば、微細なパターンを精度良く形成することができ、電子デバイスの更なる大容量化、更なる小型化を実現することが可能となる。 The sulfonium salt represented by the above formula (1) (hereinafter sometimes referred to as "sulfonium salt (1)") has excellent sensitivity to light with a wavelength of 20 nm or less, and By irradiating it, it can be easily decomposed to generate acid (H + X - ). Therefore, by using photoresist containing sulfonium salt (1) and performing photolithography using light beams with a wavelength of 20 nm or less, it is possible to form fine patterns with high precision, further increasing the capacity of electronic devices. Further miniaturization can be achieved.
　［スルホニウム塩］
　本発明のスルホニウム塩（１）は、下記式（１）で表される化合物である。
Figure JPOXMLDOC01-appb-C000003
 （式中、Ｒｆ1、Ｒｆ2、Ｒｆ11、及びＲｆ12は同一又は異なってフッ素原子又はフルオロアルキル基を示す。Ｒ1、Ｒ2、Ｒ3、Ｒ11、Ｒ12、Ｒ13、Ｒ21、Ｒ23、及びＲ25は、同一又は異なって水素原子、水酸基、アルキル基、又はヨウ素原子を示す。Ｒ22、Ｒ24は同一又は異なって水素原子、水酸基、アルキル基、ヨウ素原子、フッ素原子、又はフルオロアルキル基を示す。Ｘ-は１価の対アニオンを示す。但し、Ｒ1、Ｒ2、Ｒ3、Ｒ11、Ｒ12、Ｒ13、及びＲ21～Ｒ25から選択される少なくとも１つはヨウ素原子を示す） [Sulfonium salt]
The sulfonium salt (1) of the present invention is a compound represented by the following formula (1).
Figure JPOXMLDOC01-appb-C000003
 (In the formula, Rf 1 , Rf 2 , Rf 11 , and Rf 12 are the same or different and represent a fluorine atom or a fluoroalkyl group. R 1 , R 2 , R 3 , R 11 , R 12 , R 13 , R 21 , R 23 and R 25 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom. R 22 and R 24 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, an iodine atom, or a fluorine atom. , or a fluoroalkyl group . X - represents a monovalent counter anion. However , at least One represents an iodine atom)
　前記アルキル基は、例えば炭素数１～５のアルキル基であり、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、ｓ－ブチル基、ｔ－ブチル基、ペンチル基等の直鎖状又は分岐鎖状アルキル基が挙げられる。前記アルキル基は、原料入手が容易な点から、炭素数１～３のアルキル基が好ましく、炭素数１又は２のアルキル基が特に好ましい。 The alkyl group is, for example, an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a s-butyl group, a t-butyl group, a pentyl group, etc. Examples include linear or branched alkyl groups. The alkyl group is preferably an alkyl group having 1 to 3 carbon atoms, particularly preferably an alkyl group having 1 or 2 carbon atoms, from the viewpoint of easy availability of raw materials.
　前記フルオロアルキル基は、アルキル基の水素原子の少なくとも１つがフッ素原子で置換された基であり、アルキル基としては前記アルキル基と同様の例が挙げられる。 The fluoroalkyl group is a group in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom, and examples of the alkyl group include the same examples as the alkyl group.
　前記フルオロアルキル基としては、アルキル基の水素原子の全てがフッ素原子で置換された基、すなわちパーフルオロアルキル基（例えば、パーフルオロＣ1-5アルキル基）が好ましい。 The fluoroalkyl group is preferably a group in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms, that is, a perfluoroalkyl group (for example, a perfluoro C 1-5 alkyl group).
　上記式（１）において、Ｒ1、Ｒ2、Ｒ3、Ｒ11、Ｒ12、Ｒ13、Ｒ21、Ｒ22、Ｒ23、Ｒ24、及びＲ25で表される基から選択される少なくとも１つはヨウ素原子を示す。なかでも、光照射により容易に分解して酸を発生する（つまり、分解効率に優れる、若しくは光感応性に優れる）点で、前記基から選択される２つ以上がヨウ素原子である化合物が好ましく、３つ以上がヨウ素原子である化合物が特に好ましく、４つ以上がヨウ素原子である化合物がとりわけ好ましい。 In the above formula ( 1 ) , at least _ One represents an iodine atom. Among these, compounds in which two or more of the groups selected from the above groups are iodine atoms are preferred because they are easily decomposed by light irradiation to generate acids (that is, they have excellent decomposition efficiency or excellent photosensitivity). , compounds in which three or more are iodine atoms are particularly preferred, and compounds in which four or more are iodine atoms are particularly preferred.
　上記式（１）において、ヨウ素原子の結合する位置としては、特に制限がないが、なかでも、光照射により容易に分解して酸を発生する（つまり、分解効率に優れる、若しくは光感応性に優れる）点で、式（１）中に示される硫黄原子に対して、オルト位にヨウ素原子が結合した化合物が好ましい。 In the above formula (1), there are no particular restrictions on the bonding position of the iodine atom, but in particular, the position where the iodine atom is easily decomposed by light irradiation to generate an acid (that is, the position where the iodine atom has excellent decomposition efficiency or has low photosensitivity) A compound having an iodine atom bonded to the ortho position to the sulfur atom shown in formula (1) is preferable.
　すなわち、式（１）において、Ｒ1、Ｒ3、Ｒ11、及びＲ13で表される基から選択される少なくとも１つがヨウ素原子である化合物が好ましく、２つ以上がヨウ素原子である化合物が更に好ましい。 That is, in formula (1), a compound in which at least one selected from the groups represented by R 1 , R 3 , R 11 , and R 13 is an iodine atom is preferable, and a compound in which two or more are iodine atoms is preferable. More preferred.
　前記対アニオンとしては、例えば、ハロゲンイオン、ハロゲンオキソ酸アニオン、ホウ素アニオン、リン酸アニオン、硫酸アニオン、スルホン酸アニオン、窒素アニオン、カルボン酸アニオン、メチドアニオン、ＳｂＦ6 -、ＯＨ-、ＳＣＮ-、ＮＯ2 -、ＮＯ3 -等が挙げられる。 Examples of the counter anion include a halogen ion, a halogen oxo acid anion, a boron anion, a phosphate anion, a sulfate anion, a sulfonate anion, a nitrogen anion, a carboxylate anion, a methide anion, SbF 6 − , OH − , SCN − , NO 2- , NO3- , etc. are mentioned.
　前記ハロゲンイオンとしては、例えば、Ｃｌ-、Ｂｒ-、Ｉ-等が挙げられる。 Examples of the halogen ion include Cl − , Br − , I − and the like.
　前記ハロゲンオキソ酸アニオンとしては、例えば、ＣｌＯ4 -、ＩＯ3 -、ＢｒＯ3 -等が挙げられる。 Examples of the halogen oxoacid anion include ClO 4 - , IO 3 - , BrO 3 -, and the like.
　前記ホウ素アニオンとしては、例えば、ＢＦ4 -などの無機ホウ素アニオンや、（Ｃ6Ｆ5）4Ｂ-、（（ＣＦ3）2Ｃ6Ｈ3）4Ｂ-、テトラフェニルボレート、テトラキス(モノフルオロフェニル)ボレート、テトラキス(ジフルオロフェニル)ボレート、テトラキス(トリフルオロフェニル)ボレート等の有機ホウ素アニオンが挙げられる。 Examples of the boron anions include inorganic boron anions such as BF 4 - , (C 6 F 5 ) 4 B - , ((CF 3 ) 2 C 6 H 3 ) 4 B - , tetraphenylborate, and tetrakis(mono). Examples include organic boron anions such as fluorophenyl)borate, tetrakis(difluorophenyl)borate, and tetrakis(trifluorophenyl)borate.
　前記リン酸アニオンとしては、例えば、ＰＦ6 -、ＰＯ4 3-等の無機リン酸アニオンや、（ＣＦ3ＣＦ2）3ＰＦ3 -、（ＣＦ3ＣＦ2）2ＰＦ4 -、（ＣＦ3ＣＦ2）ＰＦ5 -等の有機リン酸アニオンが挙げられる。 Examples of the phosphate anions include inorganic phosphate anions such as PF 6 - and PO 4 3- , and (CF 3 CF 2 ) 3 PF 3 - , (CF 3 CF 2 ) 2 PF 4 - and (CF 3 ) . Examples include organic phosphate anions such as CF 2 )PF 5 - .
　前記スルホン酸アニオンは、例えば、下記式（ｓ１）で表される。
　　　Ｒs1－ＳＯ3 -　　　（ｓ１）
（式中、Ｒs1は有機基を示す） The sulfonic acid anion is represented by the following formula (s1), for example.
R s1 - SO 3 - (s1)
(In the formula, R s1 represents an organic group)
　Ｒs1における有機基としては、例えば、置換基を有していても良いＣ1-30炭化水素基、置換基を有していても良い複素環式基、及び前記基の２個以上が、単結合又は、－Ｏ－、－ＣＯ2－、－Ｓ－、－ＳＯ3－、及び－ＳＯ2Ｎ（Ｒs2）－から選択される連結基で連結された基が挙げられる。前記Ｒs2は水素原子又はアルキル基（例えば、Ｃ1-30アルキル基）を示す。前記置換基としては、例えば、フッ素原子等のハロゲン原子が挙げられる。 Examples of the organic group in R s1 include a C 1-30 hydrocarbon group that may have a substituent, a heterocyclic group that may have a substituent, and two or more of the above groups. Examples include groups connected by a single bond or a linking group selected from -O-, -CO 2 -, -S-, -SO 3 -, and -SO 2 N(R s2 )-. The R s2 represents a hydrogen atom or an alkyl group (for example, a C 1-30 alkyl group). Examples of the substituent include halogen atoms such as fluorine atoms.
　前記Ｃ1-30炭化水素基には、Ｃ1-30脂肪族炭化水素基、Ｃ3-30脂環式炭化水素基、Ｃ6-30芳香族炭化水素基、及びこれらの２個が結合した基が含まれる。 The C 1-30 hydrocarbon group has a C 1-30 aliphatic hydrocarbon group, a C 3-30 alicyclic hydrocarbon group, a C 6-30 aromatic hydrocarbon group, and two of these are bonded. Contains groups.
　前記Ｃ1-30炭化水素基としては、Ｃ1-30アルキル基、Ｃ6-15アリール基、Ｃ6-15シクロアルキル基、Ｃ6-15橋かけ環式炭化水素基、及びこれらの２個が結合した基が好ましい。 The C 1-30 hydrocarbon group includes a C 1-30 alkyl group, a C 6-15 aryl group, a C 6-15 cycloalkyl group, a C 6-15 bridged cyclic hydrocarbon group, and two of these. A group to which is bonded is preferable.
　前記複素環式基は複素環の構造式から１個の水素原子を除いた基である。前記複素環には、芳香族性複素環及び非芳香族性複素環が含まれる。このよう
な複素環としては、環を構成する原子に炭素原子と少なくとも１種のヘテロ原子（例えば、酸素原子、イオウ原子、窒素原子等）を有する３～１０員環（好ましくは４～６員環）、及びこれらの縮合環を挙げることができる。 The heterocyclic group is a group obtained by removing one hydrogen atom from the structural formula of a heterocycle. The heterocycle includes an aromatic heterocycle and a non-aromatic heterocycle. Such a heterocycle includes a 3- to 10-membered ring (preferably a 4- to 6-membered ring) having a carbon atom and at least one type of heteroatom (for example, an oxygen atom, a sulfur atom, a nitrogen atom, etc.) as atoms constituting the ring. ring), and fused rings thereof.
　前記スルホン酸アニオンの具体例としては、ＣＨ3ＳＯ3 -、Ｃ4Ｈ9ＳＯ3 -、ＣＦ3ＳＯ3 -、Ｃ2Ｆ5Ｃ4Ｈ4ＳＯ3 -、Ｃ4Ｆ9ＳＯ3 -、ベンゼンスルホン酸アニオン、ｐ－トルエンスルホン酸アニオン、カンファースルホン酸アニオンが挙げられる。 Specific examples of the sulfonic acid anions include CH 3 SO 3 - , C 4 H 9 SO 3 - , CF 3 SO 3 - , C 2 F 5 C 4 H 4 SO 3 - , C 4 F 9 SO 3 - , Examples include benzenesulfonic acid anion, p-toluenesulfonic acid anion, and camphorsulfonic acid anion.
　前記窒素アニオンとしては、例えば、下記式（ｎ１）で表されるスルホニルイミドアニオンが挙げられる。
　　　（Ｒn1ＳＯ2）2Ｎ-　　　（ｎ１）
（式中、２個のＲn1は同一又は異なって、有機基を示す） Examples of the nitrogen anion include a sulfonylimide anion represented by the following formula (n1).
(R n1 SO 2 ) 2 N - (n1)
(In the formula, two R n1s are the same or different and represent an organic group)
　Ｒn1における有機基としては、Ｒs1における有機基と同様の例が挙げられる。 Examples of the organic group for R n1 include the same examples as the organic group for R s1 .
　前記窒素アニオンの具体例としては、（ＦＳＯ2）2Ｎ-、（ＣＦ3ＳＯ2）2Ｎ-、（Ｃ4Ｆ9ＳＯ2）2Ｎ-、（Ｃ2Ｆ5ＳＯ2）2Ｎ-等が挙げられる。 Specific examples of the nitrogen anions include (FSO 2 ) 2 N - , (CF 3 SO 2 ) 2 N - , (C 4 F 9 SO 2 ) 2 N - , (C 2 F 5 SO 2 ) 2 N -. etc.
　前記カルボン酸アニオンは、例えば、下記式（ｃ１）で表される。
　　　Ｒc1－ＣＯＯ-　　　（ｃ１）
（式中、Ｒc1は有機基を示す） The carboxylic acid anion is represented by the following formula (c1), for example.
R c1 -COO - (c1)
(In the formula, R c1 represents an organic group)
　Ｒc1における有機基としては、Ｒs1における有機基と同様の例が挙げられる。 Examples of the organic group for R c1 include the same examples as the organic group for R s1 .
　前記カルボン酸アニオンの具体例としては、例えば、ＣＦ3ＣＯ2 -、ＣＨ3ＣＯ2 -、Ｃ2Ｈ5ＣＯ2 -、ＰｈＣＯ2 -等が挙げられる。 Specific examples of the carboxylic acid anion include CF 3 CO 2 - , CH 3 CO 2 - , C 2 H 5 CO 2 - , PhCO 2 -, and the like.
　前記メチドアニオンとしては、例えば、下記式（ｍ１）で表されるスルホニルメチドアニオンが挙げられる。
　　　（Ｒm1ＳＯ2）3Ｃ-　　　（ｍ１）
（式中、３個のＲm1は同一又は異なって、有機基を示す） Examples of the methide anion include a sulfonyl methide anion represented by the following formula (m1).
(R m1 SO 2 ) 3 C - (m1)
(In the formula, three R m1 are the same or different and represent an organic group)
　Ｒm1における有機基としては、Ｒs1における有機基と同様の例が挙げられる。 Examples of the organic group for R m1 include the same examples as the organic group for R s1 .
　前記メチドアニオンの具体例としては、例えば、（ＣＦ3ＳＯ2）3Ｃ-等が挙げられる。 Specific examples of the methide anion include (CF 3 SO 2 ) 3 C - and the like.
　前記対アニオンには、上記以外にも、例えば、特開２０１３－４７２１１、特開２０２１－８１７０８、特開２０１３－８０２４５、特開２０１３－８０２４０、及び特開２０１３－３３１６１に記載のアニオンが含まれる。 In addition to the above, the counteranions include, for example, anions described in JP 2013-47211, JP 2021-81708, JP 2013-80245, JP 2013-80240, and JP 2013-33161. .
　前記対アニオンとしては、溶解性に優れる点で、スルホン酸アニオン又は窒素アニオンが好ましい。 As the counter anion, a sulfonic acid anion or a nitrogen anion is preferable from the viewpoint of excellent solubility.
　上記式（１）で表されるスルホニウム塩としては、光照射により容易に分解して酸を発生する（つまり、分解効率に優れる、若しくは光感応性に優れる）点で、下記式（１ａ）で表されるスルホニウム塩又は下記式（１ｂ）で表されるスルホニウム塩が好ましい。
Figure JPOXMLDOC01-appb-C000004
 The sulfonium salt represented by the above formula (1) can be easily decomposed by light irradiation to generate an acid (that is, has excellent decomposition efficiency or excellent photosensitivity), and is therefore suitable for the following formula (1a). A sulfonium salt represented by the following formula or a sulfonium salt represented by the following formula (1b) is preferable.
Figure JPOXMLDOC01-appb-C000004
　上記式中、Ｒｆ31、Ｒｆ32は同一又は異なってフッ素原子又はフルオロアルキル基を示す。Ｒ31、Ｒ32、及びＲ33は同一又は異なって水素原子、水酸基、アルキル基、又はヨウ素原子を示す。Ｒ41、Ｒ42、Ｒ43、Ｒ44、及びＲ45は同一又は異なって水素原子、水酸基、アルキル基、又はヨウ素原子を示す。Ｘ-は１価の対アニオンを示す。 In the above formula, Rf 31 and Rf 32 are the same or different and represent a fluorine atom or a fluoroalkyl group. R 31 , R 32 and R 33 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom. R 41 , R 42 , R 43 , R 44 and R 45 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom. X − represents a monovalent counteranion.
　なお、上記式（１ａ）中の括弧で示される２個のアリール基は、同一であっても良いし、異なっていても良い。また、上記式（１ｂ）中の括弧で示される３個のアリール基は、同一であっても良いし、異なっていても良い。 Note that the two aryl groups shown in parentheses in the above formula (1a) may be the same or different. Moreover, the three aryl groups shown in parentheses in the above formula (1b) may be the same or different.
　そして、式（１ａ）中の２個のＲ31、２個のＲ32、２個のＲ33、Ｒ41、Ｒ42、Ｒ43、Ｒ44、及びＲ45から選択される少なくとも１つはヨウ素原子を示す。
　また、式（１ｂ）中の３個のＲ31、３個のＲ32、及び３個のＲ33から選択される少なくとも１つはヨウ素原子を示す。 and at least one selected from two R 31 , two R 32 , two R 33 , R 41 , R 42 , R 43 , R 44 , and R 45 in formula (1a) is iodine. Indicates an atom.
Further, at least one selected from three R 31 , three R 32 , and three R 33 in formula (1b) represents an iodine atom.
　上記式（１ａ）で表されるスルホニウム塩としては、光照射により容易に分解して酸を発生する（つまり、分解効率に優れる、若しくは光感応性に優れる）点で、下記式（１ａ－１）で表されるスルホニウム塩が好ましい。また、上記式（１ｂ）で表されるスルホニウム塩としては、光照射により容易に分解して酸を発生する（つまり、分解効率に優れる、若しくは光感応性に優れる）点で、下記式（１ｂ－１）で表されるスルホニウム塩が好ましい。
Figure JPOXMLDOC01-appb-C000005
 As the sulfonium salt represented by the above formula (1a), the following formula (1a-1 ) is preferred. In addition, the sulfonium salt represented by the above formula (1b) can be easily decomposed by light irradiation to generate an acid (that is, has excellent decomposition efficiency or excellent photosensitivity). Sulfonium salts represented by -1) are preferred.
Figure JPOXMLDOC01-appb-C000005
　上記式中、Ｒｆ31、Ｒｆ32は同一又は異なってフッ素原子又はフルオロアルキル基を示す。Ｒ31’、Ｒ33’、Ｒ41’、Ｒ42’、Ｒ43’、Ｒ44’、及びＲ45’は同一又は異なって水素原子又はヨウ素原子を示す。Ｘ-は１価の対アニオンを示す。 In the above formula, Rf 31 and Rf 32 are the same or different and represent a fluorine atom or a fluoroalkyl group. R 31 ′, R 33 ′ , R 41 ′ , R 42 ′ , R 43 ′, R 44 ′, and R 45 ′ are the same or different and represent a hydrogen atom or an iodine atom. X − represents a monovalent counteranion.
　なお、上記式（１ａ－１）中の括弧で示される２個のアリール基は、同一であっても良いし、異なっていても良い。また、上記式（１ｂ－１）中の括弧で示される３個のアリール基は、同一であっても良いし、異なっていても良い。 Note that the two aryl groups shown in parentheses in the above formula (1a-1) may be the same or different. Further, the three aryl groups shown in parentheses in the above formula (1b-1) may be the same or different.
　そして、式（１ａ－１）中の２個のＲ31、２個のＲ33’、Ｒ41’、Ｒ42’、Ｒ43’、Ｒ44’、及びＲ45’から選択される少なくとも１つはヨウ素原子を示す。
　また、式（１ｂ－１）中の３個のＲ31’及び３個のＲ33’から選択される少なくとも１つはヨウ素原子を示す。 and at least one selected from two R 31 , two R 33 ′ , R 41 ′ , R 42 ′, R 43 ′, R 44 ′, and R 45 ′ in formula (1a-1). indicates an iodine atom.
Furthermore, at least one selected from three R 31 's and three R 33 's in formula (1b-1) represents an iodine atom.
　上記式中、Ｒｆ31、Ｒｆ32としては、なかでも、分解効率に特に優れる点でフッ素原子が好ましい。 In the above formula, Rf 31 and Rf 32 are preferably fluorine atoms because of their particularly excellent decomposition efficiency.
　上記式中、Ｒ31’及びＲ33’は、なかでも、分解効率に特に優れる点で、少なくとも一方はヨウ素原子を示すことが好ましい。 In the above formula, it is preferable that at least one of R 31 ' and R 33 ' represents an iodine atom because of particularly excellent decomposition efficiency.
　上記式中、Ｒ41’、Ｒ42’、Ｒ43’、Ｒ44’、及びＲ45’で表される基のうち、少なくとも１つはヨウ素原子を示すことが好ましく、前記基から選択される２つ以上がヨウ素原子を示すことが特に好ましい。 In the above formula, at least one of the groups represented by R 41 ′ , R 42 ′, R 43 ′, R 44 ′, and R 45 ′ preferably represents an iodine atom, and is selected from the above groups. It is particularly preferred that two or more represent iodine atoms.
　上記式（１ａ－１）で表されるスルホニウム塩の具体例としては、下記式（１ａ－１－１）～（１ａ－１－３０）で表されるスルホニウム塩等が挙げられる。下記式中、Ｘ-は上記に同じである。
Figure JPOXMLDOC01-appb-C000006
 Specific examples of the sulfonium salt represented by the above formula (1a-1) include sulfonium salts represented by the following formulas (1a-1-1) to (1a-1-30). In the following formula, X - is the same as above.
Figure JPOXMLDOC01-appb-C000006
Figure JPOXMLDOC01-appb-C000007
Figure JPOXMLDOC01-appb-C000007
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000009
Figure JPOXMLDOC01-appb-C000009
　上記式（１ｂ－１）で表されるスルホニウム塩の具体例としては、下記式（１ｂ－１－１）～（１ｂ－１－１２）で表されるスルホニウム塩等が挙げられる。下記式中、Ｘ-は上記に同じである。
Figure JPOXMLDOC01-appb-C000010
 Specific examples of the sulfonium salt represented by the above formula (1b-1) include sulfonium salts represented by the following formulas (1b-1-1) to (1b-1-12). In the following formula, X - is the same as above.
Figure JPOXMLDOC01-appb-C000010
Figure JPOXMLDOC01-appb-C000011
Figure JPOXMLDOC01-appb-C000011
　また、前記スルホニウム塩（１）は有機溶剤への溶解性に優れ、２５℃における、有機溶剤（例えば、プロピレングリコールモノメチルエーテルアセテート）への溶解度は、例えば２重量％以上（例えば、２～５０重量％）、好ましくは３重量％以上、更に好ましくは４重量％以上、特に好ましくは５重量％以上である。 Further, the sulfonium salt (1) has excellent solubility in organic solvents, and the solubility in organic solvents (for example, propylene glycol monomethyl ether acetate) at 25°C is, for example, 2% by weight or more (for example, 2 to 50% by weight). %), preferably 3% by weight or more, more preferably 4% by weight or more, particularly preferably 5% by weight or more.
　前記有機溶剤としては、例えば、ベンゼン、トルエン、キシレン、エチルベンゼン等の芳香族炭化水素；プロピレンカーボネート、エチレンカーボネート、１，２－ブチレンカーボネート、ジメチルカーボネート、ジエチルカーボネート等のカーボネート；酢酸エチル、酢酸ブチル、乳酸エチル等、β－プロピオラクトン、β－ブチロラクトン、γ－ブチロラクトン、δ－バレロラクトン、ε－カプロラクトン等の鎖状又は環状エステル；；エチレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテル、ジエチレングリコールモノブチルエーテル、ジプロピレングリコールジメチルエーテル、トリエチレングリコールジエチルエーテル、トリプロピレングリコールジブチルエーテル等のグリコールジエーテル；エチレングリコールモノメチルエーテルアセテート、プロピレングリコールモノメチルエーテルアセテート、プロピレングリコールモノエチルエーテルアセテート、ジエチレングリコールモノブチルエーテルアセテート等のグリコールモノエーテルモノエステル；アセトン、メチルエチルケトン、シクロペンタノン、シクロヘキサノン、メチルイソアミルケトン、２－ヘプタノン等のケトンが挙げられる。これらは１種を単独で、又は２種以上を組み合わせて使用することができる。 Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; carbonates such as propylene carbonate, ethylene carbonate, 1,2-butylene carbonate, dimethyl carbonate, and diethyl carbonate; ethyl acetate, butyl acetate, Ethyl lactate, etc., linear or cyclic esters such as β-propiolactone, β-butyrolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone;; ethylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monobutyl ether; Glycol diethers such as dipropylene glycol dimethyl ether, triethylene glycol diethyl ether, tripropylene glycol dibutyl ether; glycol monoethers such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, etc. Monoester; Ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone can be mentioned. These can be used alone or in combination of two or more.
　前記有機溶剤としては、なかでも、ケトン、鎖状エステル、及びグリコールモノエーテルモノエステルから選択される少なくとも１種を含有することが好ましい。 The organic solvent preferably contains at least one selected from ketones, chain esters, and glycol monoether monoesters.
　前記スルホニウム塩（１）は、ＥＵＶ（極紫外線）、ＥＢ（電子線）、Ｘ線などの波長２０ｎｍ以下の光線に対して高い感光性を有する。そして、光増感剤を使用せずとも、前記波長の光線を照射するだけで、光エネルギーがダイレクトにスルホニウム塩（１）に伝播して光分解が速やかに進行し、酸（Ｈ+Ｘ-：Ｘ-は前記に同じである）を発生する。 The sulfonium salt (1) has high photosensitivity to light having a wavelength of 20 nm or less, such as EUV (extreme ultraviolet), EB (electron beam), and X-rays. Even without using a photosensitizer, simply by irradiating the light beam of the above wavelength , the light energy directly propagates to the sulfonium salt (1), and photodecomposition proceeds rapidly, resulting in acid (H + :X - is the same as above).
　前記スルホニウム塩（１）は上記特性を有するため、酸発生剤（例えば、光酸発生剤）として好適に使用することができる。 Since the sulfonium salt (1) has the above characteristics, it can be suitably used as an acid generator (for example, a photoacid generator).
　前記スルホニウム塩（１）のうち、式（１ａ－１－２２）で表されるスルホニウム塩は、例えば、下記反応により製造することができる。前記スルホニウム塩（１）のうち、式（１ａ－１－２２）で表されるスルホニウム塩以外のスルホニウム塩も、下記反応に準じた方法で製造することができる。
Figure JPOXMLDOC01-appb-C000012
Figure JPOXMLDOC01-appb-C000013
 Among the sulfonium salts (1), the sulfonium salt represented by formula (1a-1-22) can be produced, for example, by the following reaction. Among the sulfonium salts (1), sulfonium salts other than the sulfonium salt represented by formula (1a-1-22) can also be produced by a method similar to the following reaction.
Figure JPOXMLDOC01-appb-C000012
Figure JPOXMLDOC01-appb-C000013
　また、前記スルホニウム塩（１）のうち、式（１ａ－１－３）で表されるスルホニウム塩は、例えば、下記反応により製造することもできる。
Figure JPOXMLDOC01-appb-C000014
 Furthermore, among the sulfonium salts (1), the sulfonium salt represented by formula (1a-1-3) can also be produced, for example, by the following reaction.
Figure JPOXMLDOC01-appb-C000014
　上記の反応式中、Ｘ-は式（１）中のＸ-と同じであり、１価の対アニオンを示す。ＭＸは、アルカリ金属（リチウム、ナトリウム、カリウム等）カチオンと１価の対アニオンとの塩を示す。Ａはハロゲン原子を示し、Ｘ’-はＣｌ-又はトリフルオロメタンスルホン酸アニオンを示す。 In the above reaction formula, X - is the same as X - in formula (1) and represents a monovalent counter anion. MX represents a salt of an alkali metal (lithium, sodium, potassium, etc.) cation and a monovalent counter anion. A represents a halogen atom, and X′ − represents Cl − or a trifluoromethanesulfonic acid anion.
　上記反応式中、脱水縮合反応は溶剤の存在下或いは不存在下で行うことができる。脱水縮合反応を溶剤の存在下で行う場合には、例えば、アセトニトリル、酢酸エチル、テトラヒドロフラン、クロロホルム、ジクロロメタン等から選択される１種又は２種以上の溶剤を使用することができる。反応温度は、使用する溶剤の沸点にもよるが－２０～１５０℃程度である。反応時間は、１～数十時間程度である。 In the above reaction formula, the dehydration condensation reaction can be carried out in the presence or absence of a solvent. When the dehydration condensation reaction is carried out in the presence of a solvent, one or more solvents selected from, for example, acetonitrile, ethyl acetate, tetrahydrofuran, chloroform, dichloromethane, etc. can be used. The reaction temperature is about -20 to 150°C, depending on the boiling point of the solvent used. The reaction time is about 1 to several tens of hours.
　上記反応式中、グリニヤール反応は、溶剤の存在下或いは不存在下で行うことができる。グリニヤール反応を溶剤の存在下で行う場合には、グリニャール反応で用いられる一般的な溶剤（例えば、ジエチルエーテル、テトラヒドロフラン、ジクロロメタン等から選択される１種又は２種以上の溶剤）を使用することができる。反応温度は、使用する溶剤の沸点にもよるが－２０～１５０℃程度である。反応時間は、１～数十時間程度である。 In the above reaction formula, the Grignard reaction can be carried out in the presence or absence of a solvent. When carrying out the Grignard reaction in the presence of a solvent, it is possible to use a common solvent used in the Grignard reaction (for example, one or more solvents selected from diethyl ether, tetrahydrofuran, dichloromethane, etc.). can. The reaction temperature is about -20 to 150°C, depending on the boiling point of the solvent used. The reaction time is about 1 to several tens of hours.
　上記反応式中、ヨウ素化反応は、例えば、ヨウ素、一塩化ヨウ素、ヨウ化カリウム、Ｎ－ヨードスクシンイミド等のヨウ素化剤を使用して行うことができる。ヨウ素化反応は溶剤の存在下或いは不存在下で行うことができる。ヨウ素化反応を溶剤の存在下で行う場合には、例えば、アセトニトリル、酢酸エチル、テトラヒドロフラン、クロロホルム、ジクロロメタン等から選択される１種又は２種以上の溶剤を使用することができる。反応温度は、例えば－２０～８０℃程度である。反応時間は１～４８時間程度である。 In the above reaction formula, the iodination reaction can be carried out using an iodinating agent such as iodine, iodine monochloride, potassium iodide, and N-iodosuccinimide. The iodination reaction can be carried out in the presence or absence of a solvent. When the iodination reaction is carried out in the presence of a solvent, one or more solvents selected from, for example, acetonitrile, ethyl acetate, tetrahydrofuran, chloroform, dichloromethane, etc. can be used. The reaction temperature is, for example, about -20 to 80°C. The reaction time is about 1 to 48 hours.
　上記反応の雰囲気としては反応を阻害しない限り特に限定されず、例えば、空気雰囲気、窒素雰囲気、アルゴン雰囲気等の何れであってもよい。また、反応はバッチ式、セミバッチ式、連続式等の何れの方法でも行うことができる。 The atmosphere for the above reaction is not particularly limited as long as it does not inhibit the reaction, and may be any of air atmosphere, nitrogen atmosphere, argon atmosphere, etc. Further, the reaction can be carried out by any method such as a batch method, a semi-batch method, or a continuous method.
　上記反応終了後、得られた反応生成物は、例えば、濾過、濃縮、蒸留、抽出、晶析、吸着、再結晶、カラムクロマトグラフィー等の分離手段や、これらを組み合わせた分離手段により分離精製できる。 After the above reaction is completed, the obtained reaction product can be separated and purified by separation means such as filtration, concentration, distillation, extraction, crystallization, adsorption, recrystallization, column chromatography, etc., or a combination of these separation means. .
　本発明のスルホニウム塩の化学構造は、例えば、1Ｈ－、11Ｂ－、13Ｃ－、19Ｆ－、若しくは31Ｐ－核磁気共鳴スペクトル、赤外吸収スペクトル、又は元素分析等）によって同定することができる。 The chemical structure of the sulfonium salt of the present invention is identified by, for example, 1 H-, 11 B-, 13 C-, 19 F-, or 31 P-nuclear magnetic resonance spectrum, infrared absorption spectrum, or elemental analysis). be able to.
　［酸発生剤］
　本発明の酸発生剤は、前記スルホニウム塩（１）を少なくとも含有する。前記酸発生剤は、前記スルホニウム塩（１）の１種を単独で含有していても良いし、２種以上を組み合わせて含有していても良い。また、前記酸発生剤は、前記スルホニウム塩（１）以外の成分を含有していても良いが、前記酸発生剤に含まれる、光照射により分解して酸を発生する全ての化合物（１００重量％）に対して、前記スルホニウム塩（１）の占める割合は、例えば５０重量％以上であることが好ましく、より好ましくは６０重量％以上、更に好ましくは７０重量％以上、特に好ましくは８０重量％以上、最も好ましくは９０重量％以上、とりわけ好ましくは９５重量％以上である。すなわち、前記スルホニウム塩（１）以外の酸発生剤を含んでいても良いが、他の酸発生剤の含有量は、光照射により分解して酸を発生する全ての化合物（１００重量％）に対して、例えば５０重量％以下であることが好ましく、より好ましくは４０重量％以下、更に好ましくは３０重量％以下、特に好ましくは２０重量％以下、最も好ましくは１０重量％以下、とりわけ好ましくは５重量％以下である。 [Acid generator]
The acid generator of the present invention contains at least the sulfonium salt (1). The acid generator may contain one type of the sulfonium salt (1) alone, or may contain a combination of two or more types. Further, the acid generator may contain components other than the sulfonium salt (1), but all compounds contained in the acid generator that decompose and generate acid upon irradiation with light (100% by weight %), the proportion of the sulfonium salt (1) is preferably 50% by weight or more, more preferably 60% by weight or more, still more preferably 70% by weight or more, particularly preferably 80% by weight. The content is most preferably 90% by weight or more, particularly preferably 95% by weight or more. In other words, it may contain an acid generator other than the sulfonium salt (1), but the content of the other acid generator should be 100% by weight of all the compounds that decompose and generate acid upon irradiation with light. For example, it is preferably 50% by weight or less, more preferably 40% by weight or less, even more preferably 30% by weight or less, particularly preferably 20% by weight or less, most preferably 10% by weight or less, particularly preferably 5% by weight or less. % by weight or less.
　前記酸発生剤は有機溶剤への溶解性に優れ、２５℃において、有機溶剤１００重量部に溶解する前記酸発生剤（若しくは、前記スルホニウム塩（１））の量は、例えば５重量部以上、好ましくは１０重量部以上、特に好ましくは１５重量部以上、最も好ましくは２０重量部以上である。尚、前記有機溶剤としては、スルホニウム塩（１）が溶解性を示す有機溶剤と同様の例が挙げられる。 The acid generator has excellent solubility in organic solvents, and the amount of the acid generator (or the sulfonium salt (1)) that dissolves in 100 parts by weight of the organic solvent at 25°C is, for example, 5 parts by weight or more, The amount is preferably 10 parts by weight or more, particularly preferably 15 parts by weight or more, and most preferably 20 parts by weight or more. Incidentally, examples of the organic solvent include the same organic solvents in which the sulfonium salt (1) exhibits solubility.
　前記酸発生剤は、より長波長側の光線はもちろん、波長２０ｎｍ以下の光線に対しても感応性に優れ、前記光線を照射すると、容易に分解して酸（Ｈ+Ｘ-）を発生する。 The acid generator has excellent sensitivity not only to light rays with longer wavelengths but also to light rays with a wavelength of 20 nm or less, and when irradiated with the light rays, it easily decomposes and generates acid (H + X - ). .
　前記酸発生剤は前記特性を有するため、フォトレジスト用酸発生剤（特に、波長２０ｎｍ以下の光線を利用したフォトリソグラフィーに使用するフォトレジスト用酸発生剤）として好適に使用することができる。 Since the acid generator has the above-mentioned characteristics, it can be suitably used as an acid generator for photoresists (particularly an acid generator for photoresists used in photolithography using light rays with a wavelength of 20 nm or less).
　［フォトレジスト］
　本発明のフォトレジストは、前記酸発生剤（若しくは、前記スルホニウム塩（１））と酸反応性化合物を含む。 [Photoresist]
The photoresist of the present invention contains the acid generator (or the sulfonium salt (1)) and an acid-reactive compound.
　前記酸発生剤（若しくは、前記スルホニウム塩（１））の含有量は、酸反応性化合物全量の例えば０．００１～２０重量％、好ましくは０．０１～１５重量％、特に好ましくは０．０５～７重量％である。 The content of the acid generator (or the sulfonium salt (1)) is, for example, 0.001 to 20% by weight, preferably 0.01 to 15% by weight, particularly preferably 0.05% by weight, based on the total amount of acid-reactive compounds. ~7% by weight.
　前記酸発生剤（若しくは、前記スルホニウム塩（１））の含有量が、酸反応性化合物全量の０．００１重量％以上であれば、より長波長側の光線はもちろん、波長２０ｎｍ以下の光線に対しても、優れた感応性を発揮することができる。また、前記含有量が酸反応性化合物全量の２０重量％以下であれば、フォトレジストの解像度を向上する効果が得られる。 If the content of the acid generator (or the sulfonium salt (1)) is 0.001% by weight or more based on the total amount of acid-reactive compounds, it can be used not only for light rays with longer wavelengths but also for light rays with a wavelength of 20 nm or less. It can also exhibit excellent sensitivity. Further, if the content is 20% by weight or less based on the total amount of acid-reactive compounds, the effect of improving the resolution of the photoresist can be obtained.
　前記酸反応性化合物は、酸の作用によりアルカリ現像液に対する溶解性が変化する化合物である。本発明のフォトレジストは前記酸反応性化合物の１種を単独で含有しても良いし、２種以上を組み合わせて含有しても良い。 The acid-reactive compound is a compound whose solubility in an alkaline developer changes due to the action of an acid. The photoresist of the present invention may contain one kind of the above-mentioned acid-reactive compounds alone, or may contain two or more kinds in combination.
　前記酸反応性化合物には、アルカリ現像液に易溶解性を示し、酸の存在下で架橋剤と反応してアルカリ現像液に難溶或いは不溶の化合物を生成する化合物と、アルカリ現像液に難溶或いは不溶であり、酸の作用によりアルカリ現像液への溶解性が増大する化合物が含まれる。 The acid-reactive compounds include compounds that are easily soluble in alkaline developers and react with crosslinking agents in the presence of acids to produce compounds that are poorly soluble or insoluble in alkaline developers; It includes compounds that are soluble or insoluble, and whose solubility in an alkaline developer is increased by the action of an acid.
　従って、前記フォトレジストには、下記組成物（１）と組成物（２）が含まれる。
組成物（１）：前記酸発生剤と、アルカリ現像液に易溶解性を示し、酸の存在下でアルカリ現像液に難溶或いは不溶の化合物を生成するネガ型感光性樹脂（ＱＮ）を含む組成物
組成物（２）：前記酸発生剤と、アルカリ現像液に難溶或いは不溶であり、酸の作用によりアルカリ現像液への溶解性が増大するポジ型感光性樹脂（ＱＰ）を含む組成物 Therefore, the photoresist includes the following composition (1) and composition (2).
Composition (1): Contains the acid generator and a negative photosensitive resin (QN) that is easily soluble in an alkaline developer and produces a compound that is poorly soluble or insoluble in the alkaline developer in the presence of an acid. Composition Composition (2): A composition containing the acid generator and a positive photosensitive resin (QP) that is poorly soluble or insoluble in an alkaline developer and whose solubility in the alkaline developer increases by the action of an acid. thing
　前記ネガ型感光性樹脂（若しくは、ネガ型化学増幅樹脂；ＱＮ）としては、例えば、フェノール性水酸基含有樹脂（ＱＮ１）と架橋剤（ＱＮ２）を含む組成物が挙げられる。 Examples of the negative photosensitive resin (or negative chemically amplified resin; QN) include a composition containing a phenolic hydroxyl group-containing resin (QN1) and a crosslinking agent (QN2).
　フェノール性水酸基含有樹脂（ＱＮ１）は、アルカリ現像液に易溶解性を示すフェノール性水酸基を含有する樹脂であって、架橋剤と反応してアルカリ現像液に難溶化或いは不溶化する樹脂であり、例えば、ノボラック樹脂、ポリヒドロキシスチレン、ヒドロキシスチレンの共重合体、ヒドロキシスチレンとスチレンの共重合体、ヒドロキシスチレン、スチレン及び（メタ）アクリル酸誘導体の共重合体、フェノール－キシリレングリコール縮合樹脂、クレゾール－キシリレングリコール縮合樹脂、フェノール性水酸基を含有するポリイミド、フェノール性水酸基を含有するポリアミック酸、フェノール－ジシクロペンタジエン縮合樹脂等が挙げられる。これらは１種を単独で、又は２種以上を組み合わせて使用することができる。 The phenolic hydroxyl group-containing resin (QN1) is a resin containing a phenolic hydroxyl group that is easily soluble in an alkaline developer, and is a resin that reacts with a crosslinking agent to become poorly soluble or insolubilized in an alkaline developer, such as , novolac resin, polyhydroxystyrene, copolymer of hydroxystyrene, copolymer of hydroxystyrene and styrene, hydroxystyrene, copolymer of styrene and (meth)acrylic acid derivative, phenol-xylylene glycol condensation resin, cresol- Examples include xylylene glycol condensation resin, polyimide containing a phenolic hydroxyl group, polyamic acid containing a phenolic hydroxyl group, and phenol-dicyclopentadiene condensation resin. These can be used alone or in combination of two or more.
　フェノール性水酸基含有樹脂（ＱＮ１）は、成分の一部にフェノール性低分子化合物を含有していても良い。 The phenolic hydroxyl group-containing resin (QN1) may contain a phenolic low molecular compound as a part of the components.
　フェノール性水酸基含有樹脂（ＱＮ１）の、ＧＰＣで測定したポリスチレン換算重量平均分子量（Ｍｗ）は、例えば２０００～２００００である。 The polystyrene equivalent weight average molecular weight (Mw) of the phenolic hydroxyl group-containing resin (QN1) measured by GPC is, for example, 2,000 to 20,000.
　架橋剤（ＱＮ２）は、例えば酸発生剤から発生した酸により、フェノール性水酸基含有樹脂（ＱＮ１）を架橋し得る化合物であり、例えば、ビスフェノールＡ系エポキシ化合物、ビスフェノールＦ系エポキシ化合物、ビスフェノールＳ系エポキシ化合物、ノボラック樹脂系エポキシ化合物、レゾール樹脂系エポキシ化合物、ポリ（ヒドロキシスチレン）系エポキシ化合物、オキセタン化合物、メチロール基含有メラミン化合物、メチロール基含有ベンゾグアナミン化合物、メチロール基含有尿素化合物、メチロール基含有フェノール化合物、アルコキシアルキル基含有メラミン化合物、アルコキシアルキル基含有ベンゾグアナミン化合物、アルコキシアルキル基含有尿素化合物、アルコキシアルキル基含有フェノール化合物、カルボキシメチル基含有メラミン樹脂、カルボキシメチル基含有ベンゾグアナミン樹脂、カルボキシメチル基含有尿素樹脂、カルボキシメチル基含有フェノール樹脂、カルボキシメチル基含有メラミン化合物、カルボキシメチル基含有ベンゾグアナミン化合物、カルボキシメチル基含有尿素化合物及びカルボキシメチル基含有フェノール化合物等が挙げられる。これらは１種を単独で、又は２種以上を組み合わせて使用することができる。 The crosslinking agent (QN2) is a compound capable of crosslinking the phenolic hydroxyl group-containing resin (QN1) with, for example, an acid generated from an acid generator, and includes, for example, bisphenol A-based epoxy compounds, bisphenol F-based epoxy compounds, bisphenol S-based epoxy compounds, etc. Epoxy compounds, novolac resin-based epoxy compounds, resol resin-based epoxy compounds, poly(hydroxystyrene)-based epoxy compounds, oxetane compounds, methylol group-containing melamine compounds, methylol group-containing benzoguanamine compounds, methylol group-containing urea compounds, methylol group-containing phenol compounds , alkoxyalkyl group-containing melamine compounds, alkoxyalkyl group-containing benzoguanamine compounds, alkoxyalkyl group-containing urea compounds, alkoxyalkyl group-containing phenol compounds, carboxymethyl group-containing melamine resins, carboxymethyl group-containing benzoguanamine resins, carboxymethyl group-containing urea resins, Examples include carboxymethyl group-containing phenol resins, carboxymethyl group-containing melamine compounds, carboxymethyl group-containing benzoguanamine compounds, carboxymethyl group-containing urea compounds, and carboxymethyl group-containing phenol compounds. These can be used alone or in combination of two or more.
　架橋剤（ＱＮ２）の含有量は、フェノール性水酸基含有樹脂（ＱＮ１）のアルカリ現像液に対する難溶化或いは不溶化を効率よく行う観点から、フェノール性水酸基含有樹脂（ＱＮ１）中の全酸性官能基に対して、例えば１０～４０モル％である。 The content of the crosslinking agent (QN2) is determined based on the total acidic functional groups in the phenolic hydroxyl group-containing resin (QN1) from the viewpoint of efficiently making the phenolic hydroxyl group-containing resin (QN1) poorly soluble or insolubilized in an alkaline developer. For example, it is 10 to 40 mol%.
　前記ポジ型感光性樹脂（若しくは、ポジ型化学増幅樹脂；ＱＰ）としては、例えば、酸解離性基が保護基として導入されたアルカリ可溶性樹脂（保護基導入樹脂；ＱＰ１）が挙げられる。 Examples of the positive photosensitive resin (or positive chemically amplified resin; QP) include an alkali-soluble resin into which an acid-dissociable group is introduced as a protecting group (protecting group-introduced resin; QP1).
　保護基導入樹脂（ＱＰ１）は、アルカリ可溶性樹脂中の酸性官能基（例えば、フェノール性水酸基、カルボキシル基、スルホニル基等）の水素原子の一部或いは全部が酸解離性基で置換された樹脂である。 The protecting group-introduced resin (QP1) is a resin in which some or all of the hydrogen atoms of acidic functional groups (for example, phenolic hydroxyl groups, carboxyl groups, sulfonyl groups, etc.) in an alkali-soluble resin are substituted with acid-dissociable groups. be.
　保護基導入樹脂（ＱＰ１）自体はアルカリ現像液に不溶性又は難溶性の樹脂であり、酸発生剤から発生した酸（Ｈ+Ｘ-）によって酸解離性基が解離すると、アルカリ現像液に易溶解性を示すアルカリ可溶性樹脂に変化する。 The protecting group-introduced resin (QP1) itself is insoluble or poorly soluble in an alkaline developer, and when the acid-dissociable group is dissociated by the acid (H + X - ) generated from the acid generator, it becomes easily soluble in the alkaline developer. It changes into an alkali-soluble resin that exhibits properties.
　アルカリ可溶性樹脂は、例えばＨＬＢ値が４～１９（好ましくは５～１８、特に好ましくは６～１７）の樹脂である。 The alkali-soluble resin is, for example, a resin with an HLB value of 4 to 19 (preferably 5 to 18, particularly preferably 6 to 17).
　アルカリ可溶性樹脂には、フェノール性水酸基含有樹脂、カルボキシル基含有樹脂、及びスルホン酸基含有樹脂が含まれる。 Alkali-soluble resins include phenolic hydroxyl group-containing resins, carboxyl group-containing resins, and sulfonic acid group-containing resins.
　フェノール性水酸基含有樹脂としては、上記フェノール性水酸基含有樹脂（ＱＮ１）と同様の樹脂が例示される。 Examples of the phenolic hydroxyl group-containing resin include the same resins as the above-mentioned phenolic hydroxyl group-containing resin (QN1).
　カルボキシル基含有樹脂としては、カルボキシル基を有するポリマーでああれば特に制限はなく、例えば、カルボキシル基含有ビニルモノマー（Ｂａ）のホモポリマーや、カルボキシル基含有ビニルモノマー（Ｂａ）と疎水基含有ビニルモノマー（Ｂｂ）とのホモポリマーが挙げられる。 The carboxyl group-containing resin is not particularly limited as long as it is a polymer having a carboxyl group, for example, a homopolymer of a carboxyl group-containing vinyl monomer (Ba), or a carboxyl group-containing vinyl monomer (Ba) and a hydrophobic group-containing vinyl monomer. A homopolymer with (Bb) can be mentioned.
　カルボキシル基含有ビニルモノマー（Ｂａ）としては、例えば、（メタ）アクリル酸である。 An example of the carboxyl group-containing vinyl monomer (Ba) is (meth)acrylic acid.
　疎水基含有ビニルモノマー（Ｂｂ）としては、Ｃ1-20アルキル（メタ）アクリレート、脂環基含有（メタ）アクリレート等の（メタ）アクリル酸エステル（Ｂｂ１）、及びスチレン骨格を有する炭化水素モノマーやビニルナフタレン等の芳香族炭化水素モノマー（Ｂｂ２）等が挙げられる。 Examples of hydrophobic group-containing vinyl monomers (Bb) include (meth)acrylic acid esters (Bb1) such as C 1-20 alkyl (meth)acrylates and alicyclic group-containing (meth)acrylates, and hydrocarbon monomers having a styrene skeleton. Examples include aromatic hydrocarbon monomers (Bb2) such as vinylnaphthalene.
　スルホン酸基含有樹脂としては、スルホン酸基を有するポリマーであれば特に制限はなく、例えば、ビニルスルホン酸、スチレンスルホン酸等のスルホン酸基含有ビニルモノマー（Ｂｃ）と、必要により疎水基含有ビニルモノマー（Ｂｂ）とをビニル重合することで得られる。 The sulfonic acid group-containing resin is not particularly limited as long as it is a polymer having a sulfonic acid group. For example, a sulfonic acid group-containing vinyl monomer (Bc) such as vinyl sulfonic acid or styrene sulfonic acid, and if necessary, a hydrophobic group-containing vinyl It is obtained by vinyl polymerizing the monomer (Bb).
　保護基導入樹脂（ＱＰ１）が有する酸解離性基としては、例えば、メトキシメチル基、ベンジル基、ｔｅｒｔ－ブトキシカルボニルメチル基等の１－置換メチル基；１－メトキシエチル基、１－エトキシエチル基等の１－置換エチル基；ｔｅｒｔ－ブチル基等の１－分岐アルキル基；トリメチルシリル基等のシリル基；トリメチルゲルミル基等のゲルミル基；ｔｅｒｔ－ブトキシカルボニル基等のアルコキシカルボニル基；アシル基；テトラヒドロピラニル基、テトラヒドロフラニル基、テトラヒドロチオピラニル基、テトラヒドロチオフラニル基等の環式酸解離性基等が挙げられる。これらは１種を単独で含有していても良いし、２種以上を組み合わせて含有していても良い。 Examples of the acid-dissociable group possessed by the protecting group-introduced resin (QP1) include 1-substituted methyl groups such as methoxymethyl group, benzyl group, and tert-butoxycarbonylmethyl group; 1-methoxyethyl group, 1-ethoxyethyl group; 1-substituted ethyl groups such as; 1-branched alkyl groups such as tert-butyl groups; silyl groups such as trimethylsilyl groups; germyl groups such as trimethylgermyl groups; alkoxycarbonyl groups such as tert-butoxycarbonyl groups; acyl groups; Examples include cyclic acid dissociable groups such as a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, and a tetrahydrothiofuranyl group. These may contain one type alone or a combination of two or more types.
　保護基導入樹脂（ＱＰ１）における酸解離性基の導入率［すなわち、保護基導入樹脂（ＱＰ１）中の保護されていない酸性官能基と酸解離性基との合計数に対する酸解離性基の数の割合］は、酸解離性基や該基が導入されるアルカリ可溶性樹脂の種類により一概には規定できないが、好ましくは１０～１００％、さらに好ましくは１５～１００％である。 Introduction rate of acid-dissociable groups in the protecting group-introduced resin (QP1) [i.e., the number of acid-dissociable groups relative to the total number of unprotected acidic functional groups and acid-dissociable groups in the protecting group-introduced resin (QP1) The ratio] cannot be absolutely defined depending on the acid-dissociable group or the type of alkali-soluble resin into which the group is introduced, but it is preferably 10 to 100%, more preferably 15 to 100%.
　保護基導入樹脂（ＱＰ１）の、ＧＰＣで測定したポリスチレン換算重量平均分子量（Ｍｗ）は、例えば１０００～１５００００、好ましくは３０００～１０００００である。 The polystyrene equivalent weight average molecular weight (Mw) of the protecting group-introduced resin (QP1) measured by GPC is, for example, 1,000 to 150,000, preferably 3,000 to 100,000.
　本発明のフォトレジストは、例えば、前記酸発生剤（若しくは、前記スルホニウム塩（１））を有機溶剤に溶解し、これを感光性樹脂と混合することにより調製することができる。 The photoresist of the present invention can be prepared, for example, by dissolving the acid generator (or the sulfonium salt (1)) in an organic solvent and mixing this with a photosensitive resin.
　本発明のフォトレジストは、前記酸発生剤（若しくは、前記スルホニウム塩（１））と感光性樹脂以外にも必要に応じて他の成分を１種又は２種以上含有することができる。他の成分としては、例えば、有機溶剤、顔料、染料、光増感剤、分散剤、界面活性剤、充填剤、レベリング剤、消泡剤、帯電防止剤、紫外線吸収剤、ｐＨ調整剤、表面改質剤、可塑剤、乾燥促進剤等が挙げられる。 In addition to the acid generator (or the sulfonium salt (1)) and the photosensitive resin, the photoresist of the present invention may contain one or more other components as necessary. Other components include, for example, organic solvents, pigments, dyes, photosensitizers, dispersants, surfactants, fillers, leveling agents, antifoaming agents, antistatic agents, ultraviolet absorbers, pH adjusters, surface Examples include modifiers, plasticizers, drying accelerators, and the like.
　前記有機溶剤としては、前記感光性樹脂を溶解させることができ、フォトレジストに良好な塗布性を付与することができる溶剤であれば良いが、なかでも、沸点が２００℃以下のものを使用することが、フォトレジストを塗布後、容易に乾燥させることができる点で好ましい。このような有機溶剤としては、トルエン等の芳香族炭化水素；エタノール、メタノール等のアルコール；シクロヘキサノン、メチルエチルケトン、アセトン等のケトン；酢酸エチル、酢酸ブチル、乳酸エチル等のエステル；プロピレングリコールモノメチルエーテルアセテート等のグリコールモノエーテルモノエステルなどが好ましい。これらは１種を単独で、又は２種以上を組み合わせて使用することができる。 The organic solvent may be any solvent that can dissolve the photosensitive resin and impart good coating properties to the photoresist, but among them, those having a boiling point of 200° C. or lower are used. This is preferable in that the photoresist can be easily dried after coating. Examples of such organic solvents include aromatic hydrocarbons such as toluene; alcohols such as ethanol and methanol; ketones such as cyclohexanone, methyl ethyl ketone, and acetone; esters such as ethyl acetate, butyl acetate, and ethyl lactate; propylene glycol monomethyl ether acetate, etc. Glycol monoether monoesters and the like are preferred. These can be used alone or in combination of two or more.
　本発明のフォトレジストは、波長２０ｎｍ以下の光線に対して高い感応性を有するスルホニウム塩（１）を含有する。そのため、波長２０ｎｍ以下の光線を照射する場合でも、光増感剤を含有せずとも、露光部において、効率よく酸（Ｈ+Ｘ-）を発生させることができる。そして、発生した酸（Ｈ+Ｘ-）により、露光部の感光性樹脂は、現像液への溶解性が変化する。前記感光性樹脂がネガ型感光性樹脂である場合には、照射により溶解性が減少する。一方、前記感光性樹脂がポジ型感光性樹脂である場合には、照射により溶解性が増大する。そのため、本発明のフォトレジストを利用すれば、フォトリソグラフィーにより、エッチングマスクを精度良く形成することができる。 The photoresist of the present invention contains a sulfonium salt (1) that is highly sensitive to light having a wavelength of 20 nm or less. Therefore, even when irradiating with light having a wavelength of 20 nm or less, acid (H + X - ) can be efficiently generated in the exposed area without containing a photosensitizer. The generated acid (H + X - ) changes the solubility of the photosensitive resin in the exposed area in the developer. When the photosensitive resin is a negative photosensitive resin, the solubility is reduced by irradiation. On the other hand, when the photosensitive resin is a positive photosensitive resin, the solubility increases upon irradiation. Therefore, by using the photoresist of the present invention, an etching mask can be formed with high precision by photolithography.
　［電子デバイスの製造方法］
　本発明の電子デバイスの製造方法は、前記フォトレジストを使用したフォトリソグラフィーによりパターン形成を行う工程を含む。 [Manufacturing method of electronic device]
The method for manufacturing an electronic device of the present invention includes a step of forming a pattern by photolithography using the photoresist.
　前記フォトレジストを使用したフォトリソグラフィーによりパターン形成を行う工程は、好ましくは、下記工程１～３を経て基板上にエッチングマスクを形成する工程である。 The step of forming a pattern by photolithography using the photoresist is preferably a step of forming an etching mask on the substrate through steps 1 to 3 below.
工程１：基板上に、前記フォトレジストの塗膜を形成する工程
工程２：前記塗膜にパターン形状の光照射を行う工程
工程３：アルカリ現像を行う工程 Step 1: Forming the photoresist coating film on the substrate Step 2: Irradiating the coating film with light in a pattern Step 3: Performing alkaline development
　（工程１）
　本工程は、エッチングする基板上に、前記フォトレジストの塗膜を形成する工程である。前記フォトレジストの塗膜は、前記フォトレジストを、スピンコート、カーテンコート、ロールコート、スプレーコート、スクリーン印刷等公知の方法を用いて基板に塗布後、乾燥させることで形成することができる。 (Step 1)
This step is a step of forming a coating film of the photoresist on the substrate to be etched. The photoresist coating film can be formed by applying the photoresist onto a substrate using a known method such as spin coating, curtain coating, roll coating, spray coating, or screen printing, and then drying it.
　（工程２）
　本工程は、工程１を経て得られた塗膜に、パターンを有するフォトマスクを介して光照射する等の方法で、パターン形状の光照射を行う工程である。光照射に用いる光線としては、前記スルホニウム塩（１）を分解して、強酸を発生させることができれば特に制限はないが、より長波長側の光線はもちろん、ＥＵＶ（極紫外線）、ＥＢ（電子線）、Ｘ線などの波長２０ｎｍ以下の光線も好適に使用することができる。 (Step 2)
This step is a step in which the coating film obtained in Step 1 is irradiated with light in a patterned manner, such as by irradiating light through a photomask having a pattern. The light beam used for light irradiation is not particularly limited as long as it can decompose the sulfonium salt (1) and generate a strong acid; Light rays having a wavelength of 20 nm or less, such as X-rays) and X-rays, can also be suitably used.
　光照射後は、６０～２００℃の温度で、０．１～１２０分程度加熱することが、露光部と未露光部のアルカリ現像液への溶解性の差を大きくすることができる点で好ましい。 After light irradiation, heating at a temperature of 60 to 200°C for about 0.1 to 120 minutes is preferable because it can increase the difference in solubility in an alkaline developer between the exposed and unexposed areas. .
　（工程３）
　本工程は、工程２を経たフォトレジストの塗膜を、アルカリ現像処理に付す工程である。 (Step 3)
This step is a step in which the photoresist coating film that has passed through step 2 is subjected to an alkaline development treatment.
　アルカリ現像処理に使用するアルカリ現像液としては、例えば、水酸化ナトリウム水溶液、水酸化カリウム水溶液、炭酸水素ナトリウム、テトラメチルアンモニウム塩水溶液等が挙げられる。 Examples of the alkaline developer used in the alkaline development treatment include aqueous sodium hydroxide solution, aqueous potassium hydroxide solution, sodium hydrogen carbonate, and aqueous tetramethylammonium salt solution.
　前記アルカリ現像液には、メタノール、エタノール、イソプロピルアルコール、テトラヒドロフラン、Ｎ－メチルピロリドン等を添加しても良い。 Methanol, ethanol, isopropyl alcohol, tetrahydrofuran, N-methylpyrrolidone, etc. may be added to the alkaline developer.
　アルカリ現像処理は、前記塗膜に、ディップ方式、シャワー方式、スプレー方式等の方法により前記アルカリ現像液を塗布することで行われる。 The alkaline development treatment is performed by applying the alkaline developer to the coating film by a method such as a dip method, a shower method, or a spray method.
　アルカリ現像液の温度は、例えば２５～４０℃である。また、アルカリ現像時間は、レジストの厚さに応じて適宜決定されるが、例えば１～５分程度である。 The temperature of the alkaline developer is, for example, 25 to 40°C. Further, the alkaline development time is appropriately determined depending on the thickness of the resist, and is, for example, about 1 to 5 minutes.
　工程３を経て、基板上にエッチングマスクを形成することができる。このようにして得られたエッチングマスクを利用して基板をエッチングすれば、高精度の電子デバイスを製造することができる。 After Step 3, an etching mask can be formed on the substrate. By etching a substrate using the etching mask obtained in this manner, a highly accurate electronic device can be manufactured.
　前記電子デバイスには、例えば、有機ＥＬディスプレイ、液晶ディスプレイ等の表示デバイス；タッチパネル等の入力デバイス；発光デバイス；センサーデバイス；光スキャナー、光スイッチ、加速度センサー、圧力センサー、ジャイロスコープ、マイクロ流路、インクジェットヘッド等のＭＥＭＳ（Micro Electro Mechanical Systems）デバイス等が含まれる。 The electronic devices include, for example, display devices such as organic EL displays and liquid crystal displays; input devices such as touch panels; light emitting devices; sensor devices; optical scanners, optical switches, acceleration sensors, pressure sensors, gyroscopes, microchannels, This includes MEMS (Micro Electro Mechanical Systems) devices such as inkjet heads.
　以上、本発明の各構成及びそれらの組み合わせ等は一例であって、本発明の主旨から逸脱しない範囲において、適宜、構成の付加、省略、置換、及び変更が可能である。また、本発明は、実施形態によって限定されることはなく、特許請求の範囲の記載によってのみ限定される。 The configurations and combinations thereof of the present invention described above are merely examples, and additions, omissions, substitutions, and changes to the configurations can be made as appropriate without departing from the gist of the present invention. Furthermore, the present invention is not limited by the embodiments, but only by the claims.
　以下、実施例により本発明をより具体的に説明するが、本発明はこれらの実施例により限定されるものではない。 Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.
　製造例１
　１－ブロモ－３，５－ジフルオロベンゼン９６．５ｇ、マグネシウム１３．４ｇ、テトラヒドロフラン４００ｇを用いて常法により調製した３，５－ジフルオロフェニルマグネシウムブロマイドのテトラヒドロフラン溶液に、塩化チオニル２８．６ｇをテトラヒドロフラン５０ｇで希釈した溶液を、系内温度が－５℃を超えない範囲で滴下した。滴下終了後室温で１時間反応を継続し反応を完結させた。
　この溶液を、系内温度が１５℃を超えないようにイオン交換水５００ｇに加え、１時間攪拌した。その後、酢酸エチル３００ｇを投入し、１時間攪拌した。水層を除去した後、イオン交換水３００ｇで３回洗浄した。有機層を脱溶剤し、得られた茶色の残渣をシクロヘキサンで再結晶することで、ビス（３，５－ジフルオロフェニル）スルホキシド２６．０ｇを得た。 Manufacturing example 1
To a tetrahydrofuran solution of 3,5-difluorophenylmagnesium bromide prepared by a conventional method using 96.5 g of 1-bromo-3,5-difluorobenzene, 13.4 g of magnesium, and 400 g of tetrahydrofuran, 28.6 g of thionyl chloride was added to 50 g of tetrahydrofuran. The diluted solution was added dropwise within the system temperature within the range of -5°C. After the dropwise addition was completed, the reaction was continued for 1 hour at room temperature to complete the reaction.
This solution was added to 500 g of ion-exchanged water so that the system temperature did not exceed 15° C., and stirred for 1 hour. Then, 300 g of ethyl acetate was added and stirred for 1 hour. After removing the aqueous layer, it was washed three times with 300 g of ion-exchanged water. The organic layer was desolvented, and the resulting brown residue was recrystallized from cyclohexane to obtain 26.0 g of bis(3,5-difluorophenyl) sulfoxide.
　製造例２
　１－ブロモ－３，５－ジフルオロベンゼン９６．５ｇを１－ブロモ－３，５－ビストリフルオロメチルベンゼン１４６．５ｇに変更した以外は、製造例１と同様の方法で、ビス（３，５－ビストリフルオロメチルフェニル）スルホキシド４３．６ｇを得た。 Manufacturing example 2
Bis(3,5- 43.6 g of bistrifluoromethylphenyl) sulfoxide was obtained.
　製造例３
　製造例１で合成したビス（３，５－ジフルオロフェニル）スルホキシド６．８６ｇをベンゼン３０ｇに溶解させ、トリフルオロメタンスルホン酸無水物８．４６ｇを系内温度が－５℃を超えない範囲で滴下した。
滴下終了後室温で１時間反応を継続し反応を完結させた。上澄みを除去し、油状沈殿物にイオン交換水５０ｇに１５℃を超えないように加え、次いでテトラヒドロフラン７５ｇ、トルエン３０ｇを加え、１時間攪拌した。上層を除去し、残った溶液をトルエン３０ｇ部で２回洗浄した。その後溶液を炭酸水素ナトリウムで中和し、ジクロロメタン１００ｇを加え抽出し、水層を除去し、さらに有機層をイオン交換水５０ｇで３回洗浄した。有機層を脱溶剤し、結晶が析出してきたところで、メチル－ｔｅｒｔブチルエーテル１５０ｇを加え、白色の結晶を析出させた。この結晶をろ過して分取し、減圧乾燥することにより、［ビス（３，５－ジフルオロフェニル）］フェニルスルホニウムトリフルオロメタンスルホネート６．５３ｇを得た。 Manufacturing example 3
6.86 g of bis(3,5-difluorophenyl) sulfoxide synthesized in Production Example 1 was dissolved in 30 g of benzene, and 8.46 g of trifluoromethanesulfonic anhydride was added dropwise within the range where the internal temperature did not exceed -5°C. .
After the dropwise addition was completed, the reaction was continued for 1 hour at room temperature to complete the reaction. The supernatant was removed, and the oily precipitate was added to 50 g of ion-exchanged water at a temperature not exceeding 15° C., then 75 g of tetrahydrofuran and 30 g of toluene were added, and the mixture was stirred for 1 hour. The upper layer was removed, and the remaining solution was washed twice with 30 g portions of toluene. Thereafter, the solution was neutralized with sodium hydrogen carbonate, extracted with 100 g of dichloromethane, the aqueous layer was removed, and the organic layer was further washed three times with 50 g of ion-exchanged water. When the organic layer was removed from the solvent and crystals were precipitated, 150 g of methyl-tert-butyl ether was added to precipitate white crystals. The crystals were collected by filtration and dried under reduced pressure to obtain 6.53 g of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate.
　製造例４
　ビス（３，５－ジフルオロフェニル）スルホキシド６．８６ｇを、製造例２で合成したビス（３，５－ビストリフルオロメチルフェニル）スルホキシド１１．９ｇに変更した以外は、製造例３と同様の方法で、［ビス（３，５－ビストリフルオロメチルフェニル）］フェニルスルホニウムトリフルオロメタンスルホネート１．３７ｇを得た。 Production example 4
In the same manner as Production Example 3, except that 6.86 g of bis(3,5-difluorophenyl) sulfoxide was changed to 11.9 g of bis(3,5-bistrifluoromethylphenyl) sulfoxide synthesized in Production Example 2. , 1.37 g of [bis(3,5-bistrifluoromethylphenyl)]phenylsulfonium trifluoromethanesulfonate was obtained.
　製造例５
　ベンゼン３０．０ｇに代えてパラキシレン３０．０ｇを使用した以外は製造例３と同様にして、［ビス（３，５－ジフルオロフェニル）］（２，５－ジメチルフェニル）スルホニウムトリフルオロメタンスルホネート７．６７ｇを得た。 Manufacturing example 5
[Bis(3,5-difluorophenyl)](2,5-dimethylphenyl)sulfonium trifluoromethanesulfonate7. 67g was obtained.
　製造例６
　製造例１で合成したビス（３，５－ジフルオロフェニル）スルホキシド６．８６ｇとアニソール５．４０ｇをジクロロメタン２０ｇに溶解させ、トリフルオロメタンスルホン酸無水物８．４６ｇを系内温度が－５℃を超えない範囲で滴下した。滴下終了後室温で１時間反応を継続し反応を完結させた。反応液にメチル－ｔｅｒｔ－ブチルエーテル１５０ｇを加え、褐色の結晶を析出させた。この結晶をろ過して分取し、ジクロロメタン３０ｇに溶解させ、三臭化ホウ素の１７％ジクロロメタン溶液１００ｇを系内温度が１０℃を超えない範囲で滴下した。滴下終了後室温で１時間反応を継続し反応を完結させた。反応液にイオン交換水５０ｇを加え、炭酸水素ナトリウムで中和後、水層を除去し、さらに有機層をイオン交換水５０ｇで３回洗浄した。有機層を脱溶剤し、結晶が析出してきたところで、メチル－Ｔｅｒｔ－ブチルエーテル１５０ｇを加え、白色の結晶を析出させた。この結晶をろ過して分取し、減圧乾燥することにより、［ビス（３，５－ジフルオロフェニル）］（４－ヒドロキシフェニル）スルホニウムトリフルオロメタンスルホネート５．５８ｇを得た。 Manufacturing example 6
6.86 g of bis(3,5-difluorophenyl) sulfoxide synthesized in Production Example 1 and 5.40 g of anisole were dissolved in 20 g of dichloromethane, and 8.46 g of trifluoromethanesulfonic anhydride was added to the solution when the system temperature exceeded -5°C. It was dripped within a certain range. After the dropwise addition was completed, the reaction was continued for 1 hour at room temperature to complete the reaction. 150 g of methyl-tert-butyl ether was added to the reaction solution to precipitate brown crystals. The crystals were collected by filtration, dissolved in 30 g of dichloromethane, and 100 g of a 17% dichloromethane solution of boron tribromide was added dropwise within the system temperature within the range of 10°C. After the dropwise addition was completed, the reaction was continued for 1 hour at room temperature to complete the reaction. 50 g of ion-exchanged water was added to the reaction solution, and after neutralization with sodium hydrogen carbonate, the aqueous layer was removed, and the organic layer was further washed three times with 50 g of ion-exchanged water. When the organic layer was removed from the solvent and crystals were precipitated, 150 g of methyl-tert-butyl ether was added to precipitate white crystals. The crystals were collected by filtration and dried under reduced pressure to obtain 5.58 g of [bis(3,5-difluorophenyl)](4-hydroxyphenyl)sulfonium trifluoromethanesulfonate.
　製造例７
　脱気窒素置換した反応容器に、マグネシウム１．１ｇ、テトラヒドロフラン２３．３ｇを仕込み、１－ブロモ－３、５－ジフルオロベンゼン８．８ｇを系内温度が６０℃を超えないように滴下した。滴下終了後、４０～６０℃で１時間反応を継続して、３，５－ジフルオロフェニルマグネシウムブロマイドのテトラヒドロフラン溶液を得た。
　別に、脱気窒素置換した反応容器に、製造例１で合成したビス（３，５－ジフルオロフェニル）スルホキシド５．０ｇ、テトラヒドロフラン３０．０ｇ、トリメチルシリルトリフルオロメタンスルホネート２７．３ｇを仕込み、氷浴にて５℃まで冷却した。その後、先に合成した３，５－ジフルオロフェニルマグネシウムブロマイドのテトラヒドロフラン溶液を滴下ロートより系内温度が１５℃を超えないように滴下した。滴下終了後１０℃で１時間反応を継続し反応を完結させた。
　この溶液を、氷浴にて５℃まで冷却したイオン交換水８０．０ｇに１５℃を超えないように加え、投入終了後、２５℃を超えないように１時間攪拌した。その後、トルエン６０．０ｇを投入し、１時間攪拌した。トルエン層を除去し、残った溶液をトルエン５０．０ｇで２回洗浄した。その後、ジクロロメタン３０．０ｇを加え抽出し、水層を分離し、さらに有機層をイオン交換水７．５ｇで４回洗浄した。有機層を脱溶剤し、得られた黄色オイル状残渣にメタノール６．０ｇを加えて溶解した。この溶液をメチル－Ｔｅｒｔ－ブチルエーテル２５．０ｇに攪拌下でゆっくり投入し、結晶を析出させた。この結晶をろ過にて分取し、減圧乾燥することにより、［トリス（３，５－ジフルオロフェニル）］スルホニウムトリフルオロメタンスルホネート４．０ｇを得た。 Manufacturing example 7
1.1 g of magnesium and 23.3 g of tetrahydrofuran were placed in a deaerated reaction vessel purged with nitrogen, and 8.8 g of 1-bromo-3,5-difluorobenzene was added dropwise so that the internal temperature did not exceed 60°C. After the dropwise addition was completed, the reaction was continued for 1 hour at 40 to 60°C to obtain a tetrahydrofuran solution of 3,5-difluorophenylmagnesium bromide.
Separately, 5.0 g of bis(3,5-difluorophenyl) sulfoxide synthesized in Production Example 1, 30.0 g of tetrahydrofuran, and 27.3 g of trimethylsilyltrifluoromethanesulfonate were placed in a degassed reaction vessel purged with nitrogen, and placed in an ice bath. Cooled to 5°C. Thereafter, a tetrahydrofuran solution of 3,5-difluorophenylmagnesium bromide synthesized earlier was added dropwise from the dropping funnel so that the temperature inside the system did not exceed 15°C. After the dropwise addition was completed, the reaction was continued at 10° C. for 1 hour to complete the reaction.
This solution was added to 80.0 g of ion-exchanged water cooled to 5°C in an ice bath so as not to exceed 15°C, and after the addition was completed, the solution was stirred for 1 hour so as not to exceed 25°C. Then, 60.0 g of toluene was added and stirred for 1 hour. The toluene layer was removed, and the remaining solution was washed twice with 50.0 g of toluene. Thereafter, 30.0 g of dichloromethane was added for extraction, the aqueous layer was separated, and the organic layer was further washed four times with 7.5 g of ion-exchanged water. The organic layer was desolvented, and 6.0 g of methanol was added to the obtained yellow oily residue to dissolve it. This solution was slowly added to 25.0 g of methyl-tert-butyl ether under stirring to precipitate crystals. The crystals were collected by filtration and dried under reduced pressure to obtain 4.0 g of [tris(3,5-difluorophenyl)]sulfonium trifluoromethanesulfonate.
　実施例１
　製造例３で合成した［ビス（３，５－ジフルオロフェニル）］フェニルスルホニウムトリフルオロメタンスルホネート６．５３ｇをジクロロメタン２７．９ｇに溶解させ、トリフルオロメタンスルホン酸５０．６ｇを加えた後、Ｎ－ヨードスクシンイミド３．３４ｇを系内温度が５℃を超えない範囲で滴下投入した。投入終了後、室温で１時間反応を継続し反応を完結させた。
　イオン交換水３６．４ｇを、系内温度が１５℃を超えないように加えて３０分撹拌した。
　その後、上層を除去し、残った溶液を５％チオ硫酸ナトリウム水溶液３６．４ｇで２回洗浄し、更に、イオン交換水３６．４ｇで３回洗浄した。
　有機層を脱溶剤して粗結晶を得、これをシリカゲルカラムクロマトグラフィーにより精製して、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（１）］５．３５ｇを得た。 Example 1
6.53 g of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate synthesized in Production Example 3 was dissolved in 27.9 g of dichloromethane, and 50.6 g of trifluoromethanesulfonic acid was added thereto, followed by N-iodosuccinimide. 3.34 g was added dropwise within the system temperature within the range of not exceeding 5°C. After the addition, the reaction was continued for 1 hour at room temperature to complete the reaction.
36.4 g of ion-exchanged water was added so that the temperature inside the system did not exceed 15° C., and the mixture was stirred for 30 minutes.
Thereafter, the upper layer was removed, and the remaining solution was washed twice with 36.4 g of a 5% aqueous sodium thiosulfate solution, and further washed three times with 36.4 g of ion-exchanged water.
The organic layer was desolvented to obtain crude crystals, which were purified by silica gel column chromatography to obtain 5.35 g of a sulfonium salt [acid generator (1)] which is a salt of a cation and anion listed in the table below. Ta.
　実施例２
　製造例１で合成したビス（３，５－ジフルオロフェニル）スルホキシド６．８６ｇをヨードベンゼン７８．３ｇに溶解させ、トリフルオロメタンスルホン酸無水物８．４６ｇを系内温度が－５℃を超えない範囲で滴下した。
　滴下終了後室温で１時間反応を継続し反応を完結させた。上澄みを除去し、油状沈殿物にイオン交換水５０ｇに１５℃を超えないように加え、次いでテトラヒドロフラン７５ｇ、トルエン３０ｇを加え、１時間攪拌した。上層を除去し、残った溶液をトルエン３０ｇ部で２回洗浄した。その後溶液を炭酸水素ナトリウムで中和し、ジクロロメタン１００ｇを加え抽出し、水層を除去し、さらに有機層をイオン交換水５０ｇで３回洗浄した。有機層を脱溶剤し、結晶が析出してきたところで、メチル－ｔｅｒｔブチルエーテル１５０ｇを加え、白色の結晶を析出させた。この結晶をろ過して分取し、減圧乾燥することにより、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（２）］８．２３ｇを得た。 Example 2
6.86 g of bis(3,5-difluorophenyl) sulfoxide synthesized in Production Example 1 was dissolved in 78.3 g of iodobenzene, and 8.46 g of trifluoromethanesulfonic anhydride was added in a range where the internal temperature of the system did not exceed -5°C. It was dripped.
After the dropwise addition was completed, the reaction was continued for 1 hour at room temperature to complete the reaction. The supernatant was removed, and the oily precipitate was added to 50 g of ion-exchanged water at a temperature not exceeding 15° C., then 75 g of tetrahydrofuran and 30 g of toluene were added, and the mixture was stirred for 1 hour. The upper layer was removed, and the remaining solution was washed twice with 30 g portions of toluene. Thereafter, the solution was neutralized with sodium hydrogen carbonate, extracted with 100 g of dichloromethane, the aqueous layer was removed, and the organic layer was further washed three times with 50 g of ion-exchanged water. When the organic layer was removed from the solvent and crystals were precipitated, 150 g of methyl-tert-butyl ether was added to precipitate white crystals. The crystals were collected by filtration and dried under reduced pressure to obtain 8.23 g of a sulfonium salt [acid generator (2)] which is a salt of a cation and anion listed in the table below.
　実施例３
　製造例３で合成した［ビス（３，５－ジフルオロフェニル）］フェニルスルホニウムトリフルオロメタンスルホネート６．５３ｇをジクロロメタン２７．９ｇに溶解させ、トリフルオロメタンスルホン酸５０．６ｇを加えた後、Ｎ－ヨードスクシンイミド１０．０１ｇを系内温度が５℃を超えない範囲で滴下投入した。
　投入終了後、室温で１０時間反応を継続し反応を完結させた。イオン交換水３６．４ｇを、系内温度が１５℃を超えないように加えて３０分撹拌した。上層を除去し、残った溶液を５％チオ硫酸ナトリウム水溶液３６．４ｇで２回洗浄し、その後イオン交換水３６．４ｇで３回洗浄した。有機層を脱溶剤して粗結晶を得、これをシリカゲルカラムクロマトグラフィーにより精製することにより、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（３）］７．５５ｇを得た。 Example 3
6.53 g of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate synthesized in Production Example 3 was dissolved in 27.9 g of dichloromethane, and 50.6 g of trifluoromethanesulfonic acid was added thereto, followed by N-iodosuccinimide. 10.01 g was added dropwise within the system temperature within the range of not exceeding 5°C.
After the addition, the reaction was continued for 10 hours at room temperature to complete the reaction. 36.4 g of ion-exchanged water was added so that the temperature inside the system did not exceed 15° C., and the mixture was stirred for 30 minutes. The upper layer was removed, and the remaining solution was washed twice with 36.4 g of a 5% aqueous sodium thiosulfate solution, and then three times with 36.4 g of ion-exchanged water. The organic layer was desolvented to obtain crude crystals, which were purified by silica gel column chromatography to obtain 7.55 g of sulfonium salts [acid generator (3)], which are salts of cations and anions listed in the table below. Obtained.
　実施例４
　製造例３で合成した［ビス（３，５－ジフルオロフェニル）］フェニルスルホニウムトリフルオロメタンスルホネート６．５３ｇをジクロロメタン２７．９ｇに溶解させ、トリフルオロメタンスルホン酸５０．６ｇを加えた後、Ｎ－ヨードスクシンイミド１３．３５ｇを系内温度が５℃を超えない範囲で滴下投入した。
　投入終了後、室温で２０時間反応を継続し反応を完結させた。イオン交換水３６．４ｇを、系内温度が１５℃を超えないように加えて３０分撹拌した。上層を除去し、残った溶液を５％チオ硫酸ナトリウム水溶液３６．４ｇで２回洗浄し、その後イオン交換水３６．４ｇで３回洗浄した。有機層を脱溶剤して粗結晶を得、これをシリカゲルカラムクロマトグラフィーにより精製することにより、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（４）］８．６６ｇを得た。 Example 4
6.53 g of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate synthesized in Production Example 3 was dissolved in 27.9 g of dichloromethane, and 50.6 g of trifluoromethanesulfonic acid was added thereto, followed by N-iodosuccinimide. 13.35 g was added dropwise to the system while the temperature within the system did not exceed 5°C.
After the addition, the reaction was continued at room temperature for 20 hours to complete the reaction. 36.4 g of ion-exchanged water was added so that the temperature inside the system did not exceed 15° C., and the mixture was stirred for 30 minutes. The upper layer was removed, and the remaining solution was washed twice with 36.4 g of a 5% aqueous sodium thiosulfate solution, and then three times with 36.4 g of ion-exchanged water. The organic layer was desolvented to obtain crude crystals, which were purified by silica gel column chromatography to obtain 8.66 g of a sulfonium salt [acid generator (4)] which is a salt of a cation and anion listed in the table below. Obtained.
　実施例５
　［ビス（３，５－ジフルオロフェニル）］フェニルスルホニウムトリフルオロメタンスルホネートに代えて、製造例４で合成した［ビス（３，５－ビストリフルオロメチルフェニル）］フェニルスルホニウムトリフルオロメタンスルホネート９．２２ｇを使用した以外は実施例１と同様にして、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（５）］７．１０ｇを得た。 Example 5
Instead of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate, 9.22 g of [bis(3,5-bistrifluoromethylphenyl)]phenylsulfonium trifluoromethanesulfonate synthesized in Production Example 4 was used. In the same manner as in Example 1 except for this, 7.10 g of a sulfonium salt [acid generator (5)] which is a salt of a cation and anion listed in the table below was obtained.
　実施例６
　　［ビス（３，５－ジフルオロフェニル）］フェニルスルホニウムトリフルオロメタンスルホネートに代えて、製造例５で合成した［ビス（３，５－ジフルオロフェニル）］（２，５－ジメチルフェニル）スルホニウムトリフルオロメタンスルホネート６．９１ｇを使用した以外は実施例１と同様にして、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（６）］５．５９ｇを得た。 Example 6
In place of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate, [bis(3,5-difluorophenyl)](2,5-dimethylphenyl)sulfonium trifluoromethanesulfonate 6 synthesized in Production Example 5 5.59 g of a sulfonium salt [acid generator (6)] which is a salt of a cation and anion listed in the table below was obtained in the same manner as in Example 1 except that .91 g was used.
　実施例７
　［ビス（３，５－ジフルオロフェニル）］フェニルスルホニウムトリフルオロメタンスルホネートに代えて、製造例６で合成した［ビス（３，５－ジフルオロフェニル）］（４－ヒドロキシフェニル）スルホニウムトリフルオロメタンスルホネート６．７５ｇを使用した以外は実施例１と同様にして、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（７）］５．４９ｇを得た。 Example 7
In place of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate, 6.75 g of [bis(3,5-difluorophenyl)](4-hydroxyphenyl)sulfonium trifluoromethanesulfonate synthesized in Production Example 6. 5.49 g of a sulfonium salt [acid generator (7)], which is a salt of a cation and anion shown in the table below, was obtained in the same manner as in Example 1 except that .
　実施例８
　［ビス（３，５－ジフルオロフェニル）］フェニルスルホニウムトリフルオロメタンスルホネートに代えて、製造例７で合成した［トリス（３，５－ジフルオロフェニル）］スルホニウムトリフルオロメタンスルホネート７．０２ｇを使用した以外は実施例１と同様にして、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（８）］５．６６ｇを得た。 Example 8
The same procedure was carried out except that 7.02 g of [tris(3,5-difluorophenyl)]sulfonium trifluoromethanesulfonate synthesized in Production Example 7 was used instead of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate. In the same manner as in Example 1, 5.66 g of a sulfonium salt [acid generator (8)] which is a salt of a cation and anion listed in the table below was obtained.
　実施例９
　製造例７で合成した［トリス（３，５－ジフルオロフェニル）］スルホニウムトリフルオロメタンスルホネート７．０２ｇをジクロロメタン２７．９ｇに溶解させ、トリフルオロメタンスルホン酸５０．６ｇを加えた後、Ｎ－ヨードスクシンイミド６．６７ｇを系内温度が５℃を超えない範囲で滴下投入した。
　投入終了後、室温で１０時間反応を継続し反応を完結させた。イオン交換水３６．４ｇを系内温度が１５℃を超えないように加えて３０分撹拌した。上層を除去し、残った溶液を５％チオ硫酸ナトリウム水溶液３６．４ｇで２回洗浄し、その後イオン交換水３６．４ｇで３回洗浄した。有機層を脱溶剤して粗結晶を得、これをシリカゲルカラムクロマトグラフィーにより精製することにより、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（９）］６．７７ｇを得た。 Example 9
7.02 g of [tris(3,5-difluorophenyl)]sulfonium trifluoromethanesulfonate synthesized in Production Example 7 was dissolved in 27.9 g of dichloromethane, and after adding 50.6 g of trifluoromethanesulfonic acid, N-iodosuccinimide 6 .67 g was added dropwise within the range where the temperature inside the system did not exceed 5°C.
After the addition, the reaction was continued for 10 hours at room temperature to complete the reaction. 36.4 g of ion-exchanged water was added so that the temperature inside the system did not exceed 15° C., and the mixture was stirred for 30 minutes. The upper layer was removed, and the remaining solution was washed twice with 36.4 g of a 5% aqueous sodium thiosulfate solution, and then three times with 36.4 g of ion-exchanged water. The organic layer was desolvented to obtain crude crystals, which were purified by silica gel column chromatography to obtain 6.77 g of a sulfonium salt [acid generator (9)] which is a salt of a cation and anion listed in the table below. Obtained.
　実施例１０
　［ビス（３，５－ジフルオロフェニル）］フェニルスルホニウムトリフルオロメタンスルホネートに代えて、製造例７で合成した［トリス（３，５－ジフルオロフェニル）］スルホニウムトリフルオロメタンスルホネート７．０２ｇを使用した以外は実施例３と同様にして、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（１０）］７．８７ｇを得た。 Example 10
The same procedure was carried out except that 7.02 g of [tris(3,5-difluorophenyl)]sulfonium trifluoromethanesulfonate synthesized in Production Example 7 was used instead of [bis(3,5-difluorophenyl)]phenylsulfonium trifluoromethanesulfonate. In the same manner as in Example 3, 7.87 g of a sulfonium salt [acid generator (10)] which is a salt of a cation and anion listed in the table below was obtained.
　実施例１１
　実施例１０で合成した（１－１０）で表されるスルホニウム塩７．８７ｇをジクロロメタン２５．４ｇに溶解させ、５％ノナフルオロブタンスルホン酸カリウム水溶液６５．２ｇ中に投入した後、２５℃で２時間撹拌した。水層を除去した後、有機層をイオン交換水２３．７ｇで数回洗浄し、減圧乾燥することにより、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（１１）］８．２７ｇを得た。 Example 11
7.87 g of the sulfonium salt represented by (1-10) synthesized in Example 10 was dissolved in 25.4 g of dichloromethane, poured into 65.2 g of a 5% potassium nonafluorobutanesulfonate aqueous solution, and then heated at 25°C. Stirred for 2 hours. After removing the aqueous layer, the organic layer was washed several times with 23.7 g of ion-exchanged water and dried under reduced pressure. 8.27g was obtained.
　実施例１２
　５％ノナフルオロブタンスルホン酸カリウム水溶液に代えて、１０％ビス（ノナフルオロブタンスルホニル）イミドリチウム水溶液５６．６ｇを使用した以外は実施例１１と同様にして、下記表に記載のカチオンとアニオンの塩であるスルホニウム塩［酸発生剤（１２）］１０．４８ｇを得た。 Example 12
The cations and anions listed in the table below were prepared in the same manner as in Example 11, except that 56.6 g of a 10% bis(nonafluorobutanesulfonyl)imide lithium aqueous solution was used instead of the 5% potassium nonafluorobutanesulfonate aqueous solution. 10.48 g of a sulfonium salt [acid generator (12)] was obtained.
　（評価）
　実施例で得られた酸発生剤、及び下記表３の比較例に記載の酸発生剤について、溶剤溶解性及び光感応性を以下の方法で評価した。結果を下記表に示す。 (evaluation)
The acid generators obtained in Examples and the acid generators described in Comparative Examples in Table 3 below were evaluated for solvent solubility and photosensitivity using the following methods. The results are shown in the table below.
　＜溶剤溶解性＞
　試験管に、酸発生剤を０．１ｇ仕込み、２５℃温調下でプロピレングリコールモノメチルエーテルアセテートを０．２ｇずつ、前記酸発生剤が完全に溶解するまで加えて、完全に溶解した時の前記酸発生剤の濃度を求め、下記基準で溶剤溶解性を評価した。
評価基準
良（◎）：酸発生剤濃度が５重量％以上
可（○）：酸発生剤濃度が２重量％以上、５重量％未満
不可（×）：酸発生剤濃度が２重量％未満 <Solvent solubility>
0.1 g of acid generator was placed in a test tube, and 0.2 g of propylene glycol monomethyl ether acetate was added under temperature control at 25°C until the acid generator was completely dissolved. The concentration of the acid generator was determined, and the solvent solubility was evaluated according to the following criteria.
Evaluation criteria Good (◎): Acid generator concentration is 5% by weight or more (○): Acid generator concentration is 2% by weight or more, but not less than 5% by weight (×): Acid generator concentration is less than 2% by weight
　＜光感応性＞
　酸発生剤をモル濃度が２．５ｍＭになるようにアセトニトリルで希釈し、ローダミンＢベース（酸の呈色試薬、Ｓｉｇｍａ－Ａｌｄｒｉｃｈ製）をモル濃度が２．５ｍＭになるように加えて、試料溶液とした。 <Light sensitivity>
Dilute the acid generator with acetonitrile to a molar concentration of 2.5 mM, add rhodamine B base (acid coloring reagent, manufactured by Sigma-Aldrich) to a molar concentration of 2.5 mM, and prepare the sample solution. And so.
　得られた試料溶液を、光路長１ｃｍの石英セルに入れ、露光装置（ＪＥＯＬ　ＪＢＸ－９３００、日本電子（株）製）を用いて、加速電圧１００ｋＶ、積算光量５０μＣ／ｃｍ2の条件で電子線の露光を行った。
　露光により、試料溶液中の酸発生剤が分解して酸が発生すると、発生した酸とローダミンＢベースとが反応して５５６ｎｍの吸光度が増加するため、露光後に５５６ｎｍの吸光度を測定することで、酸の発生量を求めることができる。
　吸光度は分光光度計（ＵＶ－ｖｉｓ）を使用して測定した。
　露光後の試料溶液の５５６ｎｍの吸光度から、検量線（標準物質：ｐ－トルエンスルホン酸）を用いて、露光後の試料溶液中の酸濃度を定量した。
　下記式から酸発生率を算出し、求めた酸発生率から、下記基準で光感応性を評価した。
　酸発生率（％）＝露光後の酸濃度（ｍＭ）／露光前の酸発生剤濃度（ｍＭ）×１００ The obtained sample solution was placed in a quartz cell with an optical path length of 1 cm, and exposed to an electron beam using an exposure device (JEOL JBX-9300, manufactured by JEOL Ltd.) at an accelerating voltage of 100 kV and an integrated light amount of 50 μC/cm 2 . exposure was performed.
When the acid generator in the sample solution decomposes and generates acid due to exposure to light, the generated acid reacts with Rhodamine B base and the absorbance at 556 nm increases, so by measuring the absorbance at 556 nm after exposure, The amount of acid generated can be determined.
Absorbance was measured using a spectrophotometer (UV-vis).
The acid concentration in the sample solution after exposure was determined from the absorbance at 556 nm of the sample solution after exposure using a calibration curve (standard substance: p-toluenesulfonic acid).
The acid generation rate was calculated from the following formula, and the photosensitivity was evaluated using the following criteria from the acid generation rate.
Acid generation rate (%) = acid concentration after exposure (mM) / acid generator concentration before exposure (mM) x 100
（評価基準）
優（◎）：酸発生率が５０％以上
良（○）：酸発生率が４０％以上５０％未満
可（△）：酸発生率が２０％以上４０％未満
不可（×）：酸発生率が２０％未満 (Evaluation criteria)
Excellent (◎): Acid generation rate is 50% or more. Good (○): Acid generation rate is 40% or more and less than 50%. (△): Acid generation rate is 20% or more and less than 40%. (x): Acid generation rate is not acceptable. is less than 20%
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000016
Figure JPOXMLDOC01-appb-T000016
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000017
　表１～３より、本発明の酸発生剤（若しくは、スルホニウム塩（１））は、ヨウ素原子を含有することにより、ヨウ素原子を含有しない場合に比べて、顕著に溶剤溶解性が向上し、電子線に対する光感応性が向上していることが分かる。
　本発明の酸発生剤（若しくは、スルホニウム塩（１））は、前記の通り優れた溶剤溶解性と光感応性を有するため、フォトレジスト用酸発生剤（特に、波長２０ｎｍ以下の光線を利用したフォトリソグラフィーに使用するフォトレジスト用酸発生剤）として好適に使用できること、本発明の酸発生剤（若しくは、スルホニウム塩（１））を含むフォトレジストを使用してフォトリソグラフィー（特に、波長２０ｎｍ以下の光線を利用したフォトリソグラフィー）を行えば、微細なパターンを精度良く形成することができ、電子デバイスの大容量化、小型化を実現できることが分かる。 From Tables 1 to 3, the acid generator (or sulfonium salt (1)) of the present invention has significantly improved solvent solubility by containing an iodine atom, compared to the case where it does not contain an iodine atom. It can be seen that the photosensitivity to electron beams is improved.
As mentioned above, the acid generator (or sulfonium salt (1)) of the present invention has excellent solvent solubility and photosensitivity, so it can be used as an acid generator for photoresists (especially when using light with a wavelength of 20 nm or less). The photoresist containing the acid generator (or sulfonium salt (1)) of the present invention can be suitably used as an acid generator for photoresists used in photolithography (especially for photoresists with a wavelength of 20 nm or less). It can be seen that if photolithography using light beams is performed, fine patterns can be formed with high precision, and electronic devices can be made larger in capacity and smaller in size.
　本発明のスルホニウム塩（１）は、波長２０ｎｍ以下の光線に対して優れた感応性を有し、前記波長の光を照射することで、容易に分解して酸（Ｈ+Ｘ-）を発生することができる。そのため、前記スルホニウム塩（１）を含むフォトレジストを用いて、波長２０ｎｍ以下の光線を使用したフォトリソグラフィーを行えば、微細なパターンを精度良く形成することができ、電子デバイスの更なる大容量化、更なる小型化を実現することができる。 The sulfonium salt (1) of the present invention has excellent sensitivity to light with a wavelength of 20 nm or less, and when irradiated with light of the wavelength, it decomposes easily and generates acid (H + X - ). can do. Therefore, if a photoresist containing the sulfonium salt (1) is used and photolithography is performed using a light beam with a wavelength of 20 nm or less, fine patterns can be formed with high precision, which will further increase the capacity of electronic devices. , further miniaturization can be achieved.

Claims (5)

  1. 　下記式（１）で表されるスルホニウム塩。
    Figure JPOXMLDOC01-appb-C000001
     （式中、Ｒｆ1、Ｒｆ2、Ｒｆ11、及びＲｆ12は同一又は異なってフッ素原子又はフルオロアルキル基を示す。Ｒ1、Ｒ2、Ｒ3、Ｒ11、Ｒ12、Ｒ13、Ｒ21、Ｒ23、及びＲ25は同一又は異なって水素原子、水酸基、アルキル基、又はヨウ素原子を示す。Ｒ22、Ｒ24は同一又は異なって水素原子、水酸基、アルキル基、ヨウ素原子、フッ素原子、又はフルオロアルキル基を示す。Ｘ-は１価の対アニオンを示す。但し、Ｒ1、Ｒ2、Ｒ3、Ｒ11、Ｒ12、Ｒ13、及びＲ21～Ｒ25から選択される少なくとも１つはヨウ素原子を示す）     A sulfonium salt represented by the following formula (1).
    Figure JPOXMLDOC01-appb-C000001
     (In the formula, Rf 1 , Rf 2 , Rf 11 , and Rf 12 are the same or different and represent a fluorine atom or a fluoroalkyl group. R 1 , R 2 , R 3 , R 11 , R 12 , R 13 , R 21 , R 23 and R 25 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, or an iodine atom. R 22 and R 24 are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, an iodine atom, a fluorine atom, or represents a fluoroalkyl group . _ _ _ (1 indicates an iodine atom)
  2. 　前記１価の対アニオンが、スルホン酸アニオン又は窒素アニオンである、請求項１に記載のスルホニウム塩。 The sulfonium salt according to claim 1, wherein the monovalent counteranion is a sulfonic acid anion or a nitrogen anion.
  3. 　請求項１又は２に記載のスルホニウム塩を含む酸発生剤。 An acid generator comprising the sulfonium salt according to claim 1 or 2.
  4. 　請求項３に記載の酸発生剤と酸反応性化合物を含むフォトレジスト。 A photoresist comprising the acid generator according to claim 3 and an acid-reactive compound.
  5. 　請求項４に記載のフォトレジストを使用したフォトリソグラフィーによりパターン形成を行う工程を含む、電子デバイスの製造方法。 A method for manufacturing an electronic device, comprising a step of forming a pattern by photolithography using the photoresist according to claim 4.
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