2,3,4,6 tetraiodobenzoate compound and use of the compound

Abstract

To provide a 2,3,4,6 - tetraiodobenzoate compound, an acid diffusion control agent containing the compound, a resist composition containing the acid diffusion control agent, a method for forming a resist pattern, and the like.SOLUTION: A compound represented by formula (I), wherein [A] + represents a monovalent counter cation represented by any one of formulae (1) to (4).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a 2,3,4,6-tetraiodobenzoate compound and uses of the compound (acid diffusion controller, resist composition, resist pattern formation, etc.). [Background technology]

[0002] Triiodobenzoate compounds are widely known as acid diffusion controllers (quenchers) that suppress the diffusion of acid generated from photoacid generators. This acid diffusion controller is used, for example, in a chemically amplified resist containing a photoacid generator, for the purpose of controlling the diffusion of acid into unexposed areas and improving contrast (for example, Patent Document 1, etc.).

[0003] When a triiodobenzoate compound is used as an acid diffusion controller in a chemically amplified resist, it undergoes an ion exchange reaction with the acid generated from a photoacid generator upon exposure to light, thereby exerting a quenching effect and suppressing the diffusion of the acid generated from the photoacid generator from exposed areas to unexposed areas of the resist film.

[0004] With the recent trend toward finer lithography, there is a demand for ionic acid diffusion controllers with high photodecomposition efficiency, and there is room for further improvement. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-62885 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a novel 2,3,4,6-tetraiodobenzoate compound. Another object of the present invention is to provide an acid diffusion controller containing the 2,3,4,6-tetraiodobenzoate compound, a resist composition containing the acid diffusion controller, and a method for forming a resist pattern using the resist composition. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that the compound represented by chemical formula (I) can solve the above-mentioned problems. Based on this finding, they have conducted further research and have completed the present invention.

[0008] That is, the present invention includes the following aspects. [1] A compound represented by chemical formula (I).

[0009] [ka] (In the formula, [A] + represents a monovalent counter cation represented by formula (1) to formula (4).

[0010] [ka] (In the formula, R 1a ~R 1d are the same or different and represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a phenyl group, or an aralkyl group. 2a ~R 2c , R 3a ~R 3c are the same or different and are a hydrogen atom, a halogen atom, -CF3, -SO2R 5 , -SF5, -CHR 11 CH2X 1 , an alkyl group having 1 to 10 carbon atoms, -OR 11 , -COOH, -NO2, a polymerizable group, or an acid-reactive group. 4a and R 4b are the same or different and are a hydrogen atom, a halogen atom, -CF3, -SO2R 6, -SF5, -CHR 11 CH2X 1 , an alkyl group having 1 to 10 carbon atoms, -OR 11 , -COOH, -NO2, a polymerizable group, or an acid-reactive group. 5 represents -CF3, -CF2CF3, an alkyl group having 1 to 10 carbon atoms, or a phenyl group. 6 represents an alkyl group having 1 to 10 carbon atoms or a phenyl group. 11 represents a hydrogen atom or a methyl group, and X 1 represents a halogen atom, a mesyloxy group (OMs), a tosyloxy group (OTs), or a trifluoromethanesulfonyloxy group (OTf). 1 represents a single bond, -O-, -S-, -S(O)- or -S(O)2-. m1 to m3 represent integers of 0 to 5. p1 represents an integer of 0 to 5. p2 and p3 represent integers of 0 to 4. q1 and q2 represent integers of 0 to 5. When m1 is an integer of 2 to 5, multiple R 2a may be the same or different, and when m2 is an integer of 2 to 5, multiple R 2b may be the same or different, and when m3 is an integer of 2 to 5, multiple R 2c may be the same or different. When p1 is an integer of 2 to 5, a plurality of R 3a may be the same or different, and when p2 is an integer of 2 to 4, a plurality of R 3b may be the same or different, and when p3 is an integer of 2 to 4, a plurality of R 3c may be the same or different. When q1 is an integer of 2 to 5, a plurality of R 4a may be the same or different, and when q2 is an integer of 2 to 5, a plurality of R 4b may be the same or different.)

[0011] [2] An acid diffusion controller containing the compound according to [1]. [3] A resist composition containing a polymer having a structural unit containing an acid-reactive group and the compound according to [1]. [4] A method for forming a resist pattern, comprising: A step of applying the resist composition according to [3] to a substrate to form a resist film; exposing the resist film to light; developing the exposed resist film to form a resist pattern; A forming method comprising: [Effects of the Invention]

[0012] The compound of the present invention represented by chemical formula (I) has a 2,3,4,6-tetraiodobenzoate anion in the molecule, and therefore has excellent compatibility with resins, solvents, etc., and also has high photosensitivity to actinic energy rays such as EUV (extreme ultraviolet light), EB (electron beam), X-rays, etc. Therefore, the compound of the present invention is useful as an acid diffusion controller with high photodecomposition efficiency. The acid diffusion controller of the present invention is useful, for example, as an acid diffusion controller for resists (particularly chemically amplified resists). A resist composition containing the acid diffusion controller of the present invention is suitable for use in forming a resist pattern. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below. 1. Compounds of the Present Invention The present invention relates to compounds represented by the above-mentioned chemical formula (I) (hereinafter, sometimes referred to as "compounds of the present invention"). The compounds of the present invention include compounds represented by chemical formulas (I-1) to (I-4).

[0014] [ka] (In the formula, R 1a ~R 1d , R 2a ~R 2c , R 3a ~R 3c , R 4a ~R 4b , Y 1 , m1 to m3, p1 to p3, q1 and q2 are the same as above.)

[0015] R 1a ~R 1dExamples of the alkyl group having 1 to 20 carbon atoms represented by the formula (I) include linear, branched, and cyclic alkyl groups having 1 to 20 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an octyl group, an octadecyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a 1-adamantyl group, a 2-adamantyl group, a decahydronaphthyl group, a decahydrodimethanonaphthyl group, and a norbornyl group. The compound of the present invention is expected to have improved compatibility with a polymer having a structural unit containing an acid-reactive group by having such an alkyl group.

[0016] R 1a ~R 1d Examples of the aralkyl group represented by the formula (I) include a benzyl group, a phenylethyl group, a phenylpropyl group, and a methylbenzyl group.

[0017] R 2a ~R 2c , R 3a ~R 3c , R 4a ~R 4b and X 1 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0018] R 2a ~R 2c , R 3a ~R 3c , R 4a ~R 4b , R 5 and R 6Examples of the alkyl group having 1 to 10 carbon atoms represented by the formula (I) include linear, branched, and cyclic alkyl groups having 1 to 10 carbon atoms, and specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-adamantyl group, of which a methyl group, a t-butyl group, a cyclohexyl group, a 1-adamantyl group, and the like are preferred. The presence of an alkyl group is expected to improve compatibility with a polymer having a structural unit containing an acid-reactive group.

[0019] R 2a ~R 2c , R 3a ~R 3c , R 4a ~R 4b Examples of the polymerizable group include groups having a polymerizable functional group (such as a carbon-carbon double bond). Examples of the polymerizable group include groups represented by formulae (S-1) to (S-4).

[0020] [ka] (In the formula, R 11 represents a hydrogen atom or a methyl group, and Y represents a single bond or an alkylene group having 1 to 3 carbon atoms.

[0021] Examples of the alkylene group having 1 to 3 carbon atoms represented by Y include a methylene group, an ethylene group (-CH2CH2- and -CH(CH3)-), and a propylene group (-CH2CH2CH2-, -CH2CH(CH3)-, and -CH(CH3)CH2-).

[0022] R 2a ~R 2c , R 3a ~R 3c , R 4a ~R 4b The acid-reactive group represented by the formula (I) preferably has a structure in which a polar group is protected with a group that reacts by the action of an acid (for example, a group that decomposes and leaves (leaving group)). Examples of polar groups include acidic groups (groups that dissociate in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide) such as a carboxy group, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl)(alkylcarbonyl)methylene group, an (alkylsulfonyl)(alkylcarbonyl)imide group, a bis(alkylcarbonyl)methylene group, a bis(alkylcarbonyl)imide group, a bis(alkylsulfonyl)methylene group, a bis(alkylsulfonyl)imide group, a tris(alkylcarbonyl)methylene group, and a tris(alkylsulfonyl)methylene group, as well as alcoholic hydroxyl groups. R 2a ~R 2c , R 3a ~R 3c , R 4a ~R 4b Examples of the acid-reactive group represented by the formula include groups represented by the formulae (R-1) to (R-7).

[0023] [ka] (wherein Y is the same as above. R 12 ~R 14 are the same or different and represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an aromatic group having 4 to 18 carbon atoms, or R 12 is R 13 and / or R 14 may be linked to form an aliphatic hydrocarbon ring having 3 to 20 carbon atoms together with the carbon atoms to which they are attached. 15 and R 16 are the same or different and represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. 17 represents an alkyl group having 1 to 20 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms. The -CH2- contained in the alkyl group, aliphatic hydrocarbon ring, and alicyclic hydrocarbon group may be replaced with -C(O)-, -O-, or -S-. a represents an integer of 0 to 4. However, in formula (R-1), formula (R-3), and formulas (R-5) to (R-7), R 12 ~R14 Except when all are hydrogen atoms.)

[0024] R 12 ~R 14 , R 17 Examples of the alkyl group having 1 to 20 carbon atoms represented by the formula (I) include linear, branched, and cyclic alkyl groups having 1 to 20 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an octyl group, an octadecyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a 1-adamantyl group, a 2-adamantyl group, a decahydronaphthyl group, a decahydrodimethanonaphthyl group, and a norbornyl group.

[0025] R 15 and R 16 Examples of the alkyl group having 1 to 6 carbon atoms represented by the formula (I) include linear or branched alkyl groups having 1 to 6 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-pentyl group, and an n-hexyl group.

[0026] R 12 ~R 14 Examples of the alkenyl group having 2 to 8 carbon atoms represented by the formula (I) include linear, branched, or cyclic alkenyl groups having 2 to 8 carbon atoms, and specific examples thereof include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, t-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, nonenyl, and norbornenyl groups.

[0027] R 12 ~R 14 Examples of the aromatic group having 4 to 18 carbon atoms and represented by the formula (I) include monocyclic or bicyclic or higher aromatic groups (aryl groups, heteroaryl groups, etc.), such as aryl groups such as phenyl group, naphthyl group, anthryl group, biphenylyl group, and phenanthryl group, and heteroaryl groups such as furyl group.

[0028] R12 and R 13 and / or R 14 Examples of the aliphatic hydrocarbon ring having 3 to 20 carbon atoms formed by linking these rings together with the carbon atoms to which they are bonded include monocyclic or bicyclic or more saturated or unsaturated alicyclic hydrocarbon rings, such as a cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, adamantane ring, decahydronaphthalene ring, decahydrodimethanonaphthalene ring, norbornane ring, and norbornene ring. Furthermore, examples of rings in which -CH2- contained in an aliphatic hydrocarbon ring is replaced by -C(O)-, -O-, or -S- include a tetrahydrofuran ring, a (methoxymethyl)tetrahydrofuran ring, a tetrahydropyran ring, an oxathiane ring, and an oxabicycloheptane ring.

[0029] R 17 Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms and represented by the formula (I) include saturated or unsaturated alicyclic hydrocarbon groups having a single ring or two or more rings, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a 1-adamantyl group, a 2-adamantyl group, a decahydronaphthyl group, a decahydrodimethanonaphthyl group, a norbornyl group, and a norbornenyl ring. Furthermore, examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced by -C(O)-, -O-, or -S- include a tetrahydrofuranyl group, a (methoxymethyl)tetrahydrofuranyl group, a tetrahydropyranyl group, an oxathianyl group, and an oxabicycloheptyl group.

[0030] The compounds of the present invention are composed of a 2,3,4,6-tetraiodobenzoate anion and a monovalent counter cation represented by formulas (1) to (4). Examples of the compounds of the present invention include compounds represented by chemical formulas (I-1-1) to (I-4-33).

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[0044] In the compound represented by the chemical formula (I-1), preferred substituents are as follows. R 1a ~R 1d are preferably the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a phenyl group or an aralkyl group (preferably a benzyl group).

[0045] In the compound represented by the chemical formula (I-2), preferred substituents are as follows. R 2a ~R 2c are the same or different and are a hydrogen atom, a halogen atom (preferably a fluorine atom or an iodine atom), -CF3, -SO2R 5 , -OR 11 , —COOH, a polymerizable group, or an acid-reactive group. R 5 is preferably —CF3. R 11 is preferably a hydrogen atom or a methyl group. m1 to m3 may be the same or different and are preferably integers of 0 to 5, and more preferably integers of 1 to 3.

[0046] In the compound represented by the chemical formula (I-3), preferred substituents are as follows. R 3a ~R 3c are the same or different and are a hydrogen atom, a halogen atom (preferably a fluorine atom or an iodine atom), -CF3, -SO2R 5 , -OR 11 , —COOH, a polymerizable group, or an acid-reactive group. R 5 is preferably —CF3. R 11 is preferably a hydrogen atom or a methyl group. Y 1 is preferably a single bond, -O-, -S-, -S(O)- or -S(O)2-, and more preferably a single bond. p1 is preferably an integer of 0 to 5, and more preferably an integer of 1 to 3. p2 and p3 may be the same or different and are preferably integers of 0 to 4, and more preferably integers of 1 to 3.

[0047] In the compound represented by the chemical formula (I-4), preferred substituents are as follows. R 4a and R 4b are the same or different and are a hydrogen atom, a halogen atom (preferably a fluorine atom or an iodine atom), -CF3, -OR 11 , —COOH, a polymerizable group, or an acid-reactive group. R 11 is preferably a hydrogen atom or a methyl group. q1 and q2 may be the same or different and are preferably integers of 0 to 5, and more preferably integers of 1 to 3.

[0048] The compound of the present invention can be synthesized by, for example, synthesis methods (1) and (2).

[0049] <Synthesis method (1)> The compound of the present invention can be synthesized by reacting 2,3,4,6-tetraiodobenzoic acid represented by chemical formula (II) with a compound represented by chemical formula (III) (see reaction scheme (A)).

[0050] [ka] (In the formula, [X] - are halide ions, hydroxide ions, trifluoromethanesulfonate (TfO -), methanesulfonate (MsO - ), toluenesulfonate (TsO - ), benzenesulfonate, benzoate, methoxide, ethoxide, t-butoxide, nitrite or nitrate ions. [A] + is the same as above.)

[0051] 2,3,4,6-tetraiodobenzoic acid represented by chemical formula (II) can be synthesized in accordance with the method described in Austrian Patent No. 209897, etc.

[0052] Examples of the compound represented by chemical formula (III) include compounds represented by chemical formulas (III-1-1) to (III-4-33).

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] [ka]

[0057] [ka]

[0058] [ka]

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[0060] [ka]

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[0062] The compound represented by chemical formula (III) can be purchased as a commercially available reagent and used, or can be prepared by the method described in JP 2017-008014 A, WO 2024 / 029354 A, J.Amer.Chem.Soc.(1990),112(16),6004-6015, J.Org.Chem.(1988),5571-5573, JP 2020-152718 A, J.Org.Chem.(2017),82(15),7708-7719, WO 2020 / 094673 A, J.Org.Chem.(2011),76(13),5240-5246, CCS Chemistry(2021),3(7),1940-1948, Tetrahedron It can be synthesized in accordance with the methods described in Letters (2001), 42(5), 855-857, European Patent Application Publication No. 972761, J. Org. Chem. (2019), 84(9), 5684-5694, etc.

[0063] The amount of the compound represented by chemical formula (III) used is preferably in the range of 1 to 20 times the molar amount of 2,3,4,6-tetraiodobenzoic acid represented by chemical formula (II) used.

[0064] In carrying out this reaction, a base (i) and a reaction solvent (ii) may be used appropriately, if necessary. Examples of the base (i) include trimethylamine, triethylamine, tributylamine, N,N-diisopropylethylamine, N-methylmorpholine, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), pyridine, 4-(N,N-dimethylamino)pyridine, picoline, N,N-dimethylaniline, N,N-diethylaniline, imidazole, lithium hydride, sodium hydride, potassium hydride, lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium carbonate, sodium carbonate, and charcoal. Examples of suitable alkoxides include potassium carbonate, cesium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, cesium hydrogen carbonate, trilithium phosphate, trisodium phosphate, tripotassium phosphate, tricesium phosphate, dilithium hydrogen phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, disodium hydrogen phosphate, lithium dihydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, cesium dihydrogen phosphate, lithium acetate, sodium acetate, potassium acetate, cesium acetate, lithium alkoxides (lithium methoxide, etc.), sodium alkoxides (sodium methoxide, sodium ethoxide, etc.), potassium alkoxides (potassium t-butoxide, etc.), etc. These may be used alone or in combination of two or more.

[0065] The amount of base (i) used is preferably in the range of 1 to 20 times by mole, more preferably 1 to 10 times by mole, relative to the amount of 2,3,4,6-tetraiodobenzoic acid represented by chemical formula (II) used.

[0066] The reaction solvent (ii) is not particularly limited as long as it does not inhibit the reaction, and examples thereof include ethers such as ethyl ether, isopropyl ether, tetrahydrofuran, 1,2-dimethoxyethane, methyltetrahydrofuran, methyltetrahydropyran, methyl-t-butyl ether, diisopropyl ether, diethyl ether, 1,4-dioxane, dimethoxyethane, tetrahydropyran, and propylene glycol monomethyl ether; Hydrocarbons such as hexane and heptane; Aromatic hydrocarbons such as benzene and nitrobenzene; Halogenated hydrocarbons such as methylene chloride, methylene bromide, 1,2-dichloroethane, chloroform, and bromoform; alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, pentanol, and hexanol; Esters such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, ethyl lactate, and propylene glycol monomethyl ether acetate; These may be used in combination as needed in appropriate amounts.

[0067] In this reaction, the reaction temperature is preferably set in the range of −80 to 60° C. The reaction time is appropriately set depending on the set reaction temperature, but is preferably set in the range of 30 minutes to 24 hours.

[0068] After completion of the reaction, the target compound of the present invention can be isolated from the resulting reaction mixture by, for example, concentrating the reaction mixture by distilling off the reaction solvent or by solvent extraction. If necessary, the product can be further purified by washing with water or the like, treatment with activated carbon, silica gel chromatography, recrystallization, or the like.

[0069] <Synthesis method (2)> The compound of the present invention can be synthesized by reacting 2,3,4,6-tetraiodobenzoic acid represented by chemical formula (II) with a base represented by chemical formula (IV) (see reaction scheme (B)).

[0070] [ka]

[0071] 2,3,4,6-tetraiodobenzoic acid represented by chemical formula (II) can be synthesized in accordance with the method described in Austrian Patent No. 209897, etc.

[0072] Examples of the base represented by chemical formula (IV) include compounds having at least one amino group selected from a primary amino group, a secondary amino group, and a tertiary amino group in the molecule, such as cyclohexylamine, dimethylbenzylamine, N,N-dimethylaniline, N,N-diethylaniline, and compounds represented by chemical formulas (IV-1) to (IV-31).

[0073] [ka]

[0074] The base represented by the chemical formula (IV) can be purchased as a commercially available reagent.

[0075] The amount of the base represented by the chemical formula (IV) used is preferably in the range of 1 to 20 times the molar amount of 2,3,4,6-tetraiodobenzoic acid represented by the chemical formula (II) used.

[0076] In carrying out this reaction, a reaction solvent (iii) may be used appropriately, if necessary. The reaction solvent (iii) is not particularly limited as long as it does not inhibit the reaction, and examples thereof include ethers such as ethyl ether, isopropyl ether, tetrahydrofuran, 1,2-dimethoxyethane, methyltetrahydrofuran, methyltetrahydropyran, methyl-t-butyl ether, diisopropyl ether, diethyl ether, 1,4-dioxane, dimethoxyethane, tetrahydropyran, and propylene glycol monomethyl ether; Hydrocarbons such as hexane and heptane; Aromatic hydrocarbons such as benzene and nitrobenzene; Halogenated hydrocarbons such as methylene chloride, methylene bromide, 1,2-dichloroethane, chloroform, and bromoform; alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, pentanol, and hexanol; Esters such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, ethyl lactate, and propylene glycol monomethyl ether acetate; Examples include dimethylformamide (DMF), dimethylacetamide (DMA), N-methyl-2-pyrrolidone (NMP), water, etc., and these can be combined as necessary and used in appropriate amounts.

[0077] In this reaction, the reaction temperature is preferably set in the range of −80 to 60° C. The reaction time is appropriately set depending on the set reaction temperature, but is preferably set in the range of 30 minutes to 24 hours.

[0078] After completion of the reaction, the target compound of the present invention can be isolated from the resulting reaction mixture by, for example, concentrating the reaction mixture by distilling off the reaction solvent or by solvent extraction. If necessary, the product can be further purified by washing with water or the like, treatment with activated carbon, silica gel chromatography, recrystallization, or the like.

[0079] The compounds of the present invention obtained by the synthesis methods (1) and (2) were subjected to the addition of halide ions, hydroxide ions, trifluoromethanesulfonate (TfO - ), methanesulfonate (MsO - ), toluenesulfonate (TsO - ), benzenesulfonate, benzoate, methoxide, ethoxide, t-butoxide, nitrite or nitrate ions ([X] - ) and a monovalent counter cation ([A] + ) and salt ([A] + [X] - ) and stirring it with an aqueous solution of the compound can change the counter cation. The compound of the present invention with a modified counter anion can be isolated from this reaction solution (reaction mixture) by, for example, concentrating the reaction solution by distilling off the reaction solvent (water) or by solvent extraction. If necessary, the product can be further purified by washing with water or the like, treatment with activated carbon, silica gel chromatography, recrystallization, or the like.

[0080] 2. Acid diffusion controller and resist composition The acid diffusion controller and resist composition of the present invention contain the compound of the present invention. The compound of the present invention is expected to have high photosensitivity to actinic radiation such as EUV (extreme ultraviolet), EB (electron beam), and X-ray, and therefore can be suitably used as an acid diffusion controller for the resist composition. The resist composition of the present invention may contain, in addition to the compound of the present invention and the polymer having a structural unit containing an acid-reactive group, a photoacid generator, other acid diffusion controllers, other resins, solvents, additives, etc. as necessary. In the present invention, the resist composition refers to a mixture before curing.

[0081] [Polymer having a structural unit containing an acid-reactive group] There are no particular restrictions on the polymer having a structural unit containing an acid-reactive group that is used in the resist composition of the present invention, so long as it is a polymer that is commonly used as a material for resist compositions. The acid-reactive group preferably has a structure in which a polar group is protected with a group that reacts by the action of an acid (for example, a group that decomposes and leaves (leaving group)). Examples of polar groups include acidic groups (groups that dissociate in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide) such as a carboxy group, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl)(alkylcarbonyl)methylene group, an (alkylsulfonyl)(alkylcarbonyl)imide group, a bis(alkylcarbonyl)methylene group, a bis(alkylcarbonyl)imide group, a bis(alkylsulfonyl)methylene group, a bis(alkylsulfonyl)imide group, a tris(alkylcarbonyl)methylene group, and a tris(alkylsulfonyl)methylene group, as well as alcoholic hydroxyl groups.

[0082] Examples of the acid-reactive group include the aforementioned R 2a ~R 2c , R 3a ~R 3c , R 4a ~R 4b The acid-reactive group can be selected from those exemplified as the acid-reactive group represented by the formula (R-1) to the formula (R-7) above.

[0083] Examples of polymers having a structural unit containing an acid-reactive group include those containing the structural units (or monomers) shown in the following documents: International Publication No. 2023 / 162907 ([Chemical Formula 2] to [Chemical Formula 36]) JP 2023-016886 A ([Chemical Formula 28], [Chemical Formula 29], [Chemical Formula 49] to [Chemical Formula 53]) JP 2023-116251 A ([Chemical Formula 8] to [Chemical Formula 16]) JP 2023-116474 A ([Chemical Formula 13] to [Chemical Formula 20]) JP 2023-117394 A (

[0091] to

[0188] ) Patent Publication No. 2023-118096 (

[0021] to

[0120] ) Patent Publication No. 2023-131576 (

[0101] to

[0216] ) JP 2023-132684 A ([Chemical Formula 51] to [Chemical Formula 63]) JP 2023-133148 A ([Chemical Formula 114] to [Chemical Formula 123])

[0084] The polymer having a structural unit containing an acid-reactive group can be obtained by heating a monomer having the structural unit described above together with a radical polymerization initiator in an organic solvent to polymerize it. In this polymerization, the compound of the present invention, a photoacid generator described below, other acid diffusion controllers, etc. can be used.

[0085] Examples of the organic solvent include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and dioxane. Examples of the radical polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroyl peroxide. The temperature during polymerization is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0086] The polymer having a structural unit containing an acid-reactive group preferably has a weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) using THF as a solvent of 1,000 to 500,000, more preferably 2,000 to 30,000. If the Mw is within this range, the resist film will have good heat resistance and solubility in an alkaline developer.

[0087] To obtain a resist composition that is suitable for use with fine pattern dimensions, the Mw / Mn of the polymer having a structural unit containing an acid reactive group preferably has a narrow dispersity of 1.0 to 2.0, and especially 1.0 to 1.5. Furthermore, the polymer having a structural unit containing an acid reactive group may contain two or more polymers having different composition ratios, Mw, or Mw / Mn.

[0088] [Compounds of the present invention] The compound of the present invention has the effect of controlling the diffusion phenomenon in the resist film of the acid generated from the acid generator or the like upon exposure, and suppressing undesirable chemical reactions (for example, dissociation reaction of acid-dissociable groups) in the unexposed areas. Therefore, the compound of the present invention functions as an acid diffusion controller (quencher).

[0089] There are no particular restrictions on the amount of the compound of the present invention that can be blended in the resist composition of the present invention, and it is usually 1 to 10 parts by weight, and preferably 2 to 5 parts by weight, per 100 parts by weight of the polymer having a structural unit containing an acid reactive group.

[0090] [Photoacid generator] The resist composition of the present invention may contain a photoacid generator. As the photoacid generator, widely known ones can be used, and examples thereof include salts in which a cation and anion are paired, as shown in the following documents. <cation> International Publication No. 2023 / 162907 ([Chemical Formula 49] to [Chemical Formula 55]) JP 2023-090803 A ([Chemical Formula 20]) JP 2023-116251 A ([Chemical Formula 25], [Chemical Formula 26]) JP 2023-116474 A ([Chemical Formula 5], [Chemical Formula 7], [Chemical Formula 8], [Chemical Formula 25]) JP 2023-117394 A (

[0040] ,

[0045] ) JP 2023-118096 A (

[0132] ,

[0180] ) JP 2023-131576 A ([Chemical Formula 11] to [Chemical Formula 17]) JP 2023-131926 A ([Chemical Formula 58] to [Chemical Formula 64]) JP 2023-132684 A ([Chemical Formula 23] to [Chemical Formula 46]) JP 2023-133148 A ([Chemical Formula 40] to [Chemical Formula 63]) JP 2023-145385 A ([Chemical Formula 19] to [Chemical Formula 21]) JP 2023-145543 A ([Chemical Formula 21] to [Chemical Formula 23]) JP 2023-152629 A ([Chemical Formula 66] to [Chemical Formula 91]) <anion> International Publication No. 2023 / 162907 ([Chemical Formula 38] to [Chemical Formula 46]) JP 2023-116251 A ([Chemical Formula 27]) JP 2023-116474 A ([Chemical Formula 29]) JP 2023-118096 A (

[0175] ,

[0176] ) JP 2023-132684 A ([Chemical Formula 67] to [Chemical Formula 78]) JP 2023-133148 A ([Chemical Formula 77] to [Chemical Formula 80]) JP 2023-135555 A (counter anions of [Chemical Formula 102] to [Chemical Formula 105]) JP 2023-145543 A ([Chemical Formula 24], [Chemical Formula 25])

[0091] The amount of the photoacid generator in the resist composition of the present invention is not particularly limited, and is usually 0 to 60 parts by weight, and preferably 0 to 30 parts by weight, per 100 parts by weight of the polymer having a structural unit containing an acid reactive group.

[0092] [Other acid diffusion control agents] In the resist composition of the present invention, an acid diffusion controller other than the compound of the present invention (another acid diffusion controller) may be used as the acid diffusion controller. Other examples of the acid diffusion controller include salts in which a cation and anion are paired, as described in the following documents: <cation> International Publication No. 2023 / 162907 ([Chemical Formula 49] to [Chemical Formula 55]) JP 2023-090803 A ([Chemical Formula 20]) JP 2023-116251 A ([Chemical Formula 25], [Chemical Formula 26]) JP 2023-116474 A ([Chemical Formula 5], [Chemical Formula 7], [Chemical Formula 8], [Chemical Formula 25]) JP 2023-117394 A (

[0040] ,

[0045] ) JP 2023-118096 A (

[0132] ,

[0180] ) JP 2023-131576 A ([Chemical Formula 11] to [Chemical Formula 17]) JP 2023-131926 A ([Chemical Formula 58] to [Chemical Formula 64]) JP 2023-132684 A ([Chemical Formula 23] to [Chemical Formula 46]) JP 2023-133148 A ([Chemical Formula 40] to [Chemical Formula 63]) JP 2023-145385 A ([Chemical Formula 19] to [Chemical Formula 21]) JP 2023-145543 A ([Chemical Formula 21] to [Chemical Formula 23]) JP 2023-152629 A ([Chemical Formula 66] to [Chemical Formula 91]) <anion> International Publication No. 2023 / 157455 ([Chemical 25], [Chemical 31], [Chemical 32]) International Publication No. 2023 / 157456 ([Chemical Formula 29]) International Publication No. 2023 / 171527 (

[0355] to

[0358] , [Chemical 76] to [Chemical 78]) JP 2023-116474 A ([Chemical Formula 38], [Chemical Formula 39]) JP 2023-136980 A ([Chemical Formula 31] to [Chemical Formula 34]) JP 2023-145543 A (counter anion of [Chemical Formula 69])

[0093] The amount of the other acid diffusion controller added to the resist composition of the present invention is not particularly limited, and is usually 0 to 10 parts by weight, and preferably 0 to 5 parts by weight, per 100 parts by weight of the polymer having a structural unit containing an acid reactive group.

[0094] [Other resins] The resist composition of the present invention may contain other resins as necessary. The other resin may be a resin containing a fluorine atom (hereinafter, sometimes referred to as a "fluorine-containing resin"). When the other resin is a fluorine-containing resin, it is preferably a resin having, as a partial structure, an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom. Other resins include those containing structural units (or monomers) shown in the following documents: JP 2023-133148 A ([Chemical Formula 118] to [Chemical Formula 120]) JP 2023-132684 A ([Chemical Formula 57] to [Chemical Formula 60]) JP 2023-117394 A (

[0142] to

[0171] ) JP 2023-016886 A ([Chemical Formula 28], [Chemical Formula 52], [Chemical Formula 53])

[0095] [solvent] The resist composition of the present invention may contain a solvent as needed, as long as it can dissolve the components used to form a homogeneous solution, and any solvent can be appropriately selected from those known as solvents for conventional chemically amplified resist compositions and used. Examples of the solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; monohydric alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; Polyhydric alcohols (glycols) such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; glycol monoethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether (PGME), or dipropylene glycol monomethyl ether; glycol diethers such as ethylene glycol dimethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; cyclic ethers such as dioxane; monocarboxylic acid alkyl esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, tert-butyl acetate, methyl pyruvate, ethyl pyruvate, tert-butyl propionate, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate; glycol monoesters such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; glycol ether esters such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, and propylene glycol monotert-butyl ether acetate; Lactones such as gamma-butyrolactone; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene; Examples include dimethyl sulfoxide (DMSO). These may be used alone or in combination of two or more. Among these, PGMEA, PGME, γ-butyrolactone, EL, cyclohexanone, etc. are preferred.

[0096] [Additives] The resist composition of the present invention may contain additives as needed. Examples of additives include surfactants, dissolution inhibitors (dissolution suppressors), crosslinking agents, water repellency improvers, acetylene alcohols, plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like.

[0097] Examples of surfactants include those described in JP 2008-111103 A (

[0165] ,

[0166] ). By adding these surfactants, it is possible to further improve or control the coatability of the resist composition. There are no particular restrictions on the amount of surfactant added to the resist composition of the present invention, and it is usually 0 to 10 parts by weight per 100 parts by weight of the polymer having a structural unit containing an acid-reactive group.

[0098] Examples of dissolution inhibitors (dissolution suppressors) include compounds having a molecular weight of 100 to 1,000, preferably 150 to 800, containing two or more phenolic hydroxy groups in the molecule, in which the hydrogen atoms of the phenolic hydroxy groups have been substituted with acid labile groups in an overall ratio of 0 to 100 mol %, and compounds containing carboxy groups in the molecule in which the hydrogen atoms of the carboxy groups have been substituted with acid labile groups in an overall ratio of 50 to 100 mol %. Specific examples include compounds in which the hydrogen atoms of the hydroxyl or carboxyl groups of bisphenol A, trisphenol, phenolphthalein, cresol novolak, naphthalenecarboxylic acid, adamantanecarboxylic acid, and cholic acid have been substituted with acid labile groups, as well as those described in JP 2008-122932 A (

[0155] to

[0178] ). When the resist composition of the present invention is a positive resist composition, by blending such a dissolution inhibitor (dissolution suppressor), the difference in dissolution rate between the exposed and unexposed areas can be further increased, and resolution can be further improved. The amount of dissolution inhibitor (dissolution suppressor) blended in the resist composition of the present invention is not particularly limited, and is 0 to 50 parts by weight, preferably 0 to 40 parts by weight, per 100 parts by weight of the polymer having a structural unit containing an acid reactive group.

[0099] Examples of crosslinking agents include epoxy compounds, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyloxy groups, all of which are substituted with at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group. These may be added to the polymer or introduced as pendant groups into the polymer side chain. Compounds containing hydroxy groups may also be used as crosslinking agents. When the resist composition of the present invention is a positive resist, the dissolution rate of the exposed area can be reduced by adding a crosslinking agent, and a negative resist pattern can be obtained.

[0100] Examples of epoxy compounds include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0101] Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are methoxymethylated, or a mixture thereof; hexamethoxyethyl melamine, hexaacyloxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are acyloxymethylated, or a mixture thereof.

[0102] Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which 1 to 4 methylol groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof; tetramethoxyethylguanamine, tetraacyloxyguanamine, a compound in which 1 to 4 methylol groups of tetramethylolguanamine are acyloxymethylated, or a mixture thereof; and the like.

[0103] Examples of glycoluril compounds include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 methylol groups of tetramethylol glycoluril have been methoxymethylated or mixtures thereof, compounds in which 1 to 4 methylol groups of tetramethylol glycoluril have been acyloxymethylated or mixtures thereof, etc. Examples of urea compounds include tetramethylol urea, tetramethoxymethyl urea, compounds in which 1 to 4 methylol groups of tetramethylol urea have been methoxymethylated or mixtures thereof, tetramethoxyethyl urea, etc.

[0104] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0105] Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0106] Examples of compounds containing an alkenyloxy group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0107] There are no particular restrictions on the amount of crosslinking agent added to the resist composition of the present invention, and it is usually 0 to 50 parts by weight, and preferably 0 to 40 parts by weight, per 100 parts by weight of the polymer having a structural unit containing an acid reactive group.

[0108] The water repellency improver is not particularly limited as long as it is soluble in an alkaline developer or an organic solvent developer, and examples thereof include polymers containing a fluorinated alkyl group, polymers containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue of a specific structure, and those described in JP-A Nos. 2007-297590 and 2008-111103. By incorporating these water repellency improvers, the water repellency of the resist film surface can be improved, allowing the resist film to be used in immersion lithography without a top coat. The amount of the water repellency improver blended in the resist composition of the present invention is not particularly limited, and is 0 to 20 parts by weight, preferably 0 to 10 parts by weight, per 100 parts by weight of the polymer having a structural unit containing an acid reactive group.

[0109] Examples of acetylene alcohols include those described in JP-A-2008-122932 (

[0179] to

[0182] ). There are no particular restrictions on the amount of acetylene alcohols added in the resist composition of the present invention, and it is usually 0 to 5 parts by weight per 100 parts by weight of the polymer having a structural unit containing an acid reactive group.

[0110] [Method for preparing resist composition] The resist composition of the present invention can be prepared, for example, by mixing the compound of the present invention, the polymer having a structural unit containing an acid-reactive group, and, if necessary, a photoacid generator, other acid diffusion controllers, other resins, solvents, and additives in predetermined ratios. Furthermore, after mixing, the resist composition of the present invention is preferably filtered, for example, using a filter with a pore size of about 0.05 μm to 0.2 μm. The solids concentration of the resist composition of the present invention is usually 0.1% to 50% by mass, preferably 0.5% to 30% by mass, and more preferably 1% to 20% by mass.

[0111] 3. Resist pattern formation method When the resist composition of the present invention is used in the manufacture of various integrated circuits, known lithography techniques can be applied. For example, a pattern formation method using the resist composition of the present invention can include a method comprising the steps of: applying the resist composition of the present invention directly or indirectly to a substrate to form a resist film (coating step); exposing the resist film formed in the coating step to active energy rays (exposure step); and developing the exposed resist film using a developer to form a resist pattern (developing step).

[0112] [Coating process] The resist composition of the present invention is applied to a substrate for integrated circuit production (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective coating, etc.) or a substrate for mask circuit production (Cr, CrO, CrON, MoSi2, SiO2, etc.) by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc., so as to give a coating thickness of 0.01 to 2 μm. This is then pre-baked on a hot plate, preferably at 60 to 150°C for 10 seconds to 30 minutes, more preferably at 80 to 120°C for 30 seconds to 20 minutes, to form a resist film.

[0113] [Exposure process] The resist film formed in the coating step is exposed to active energy rays. Examples of active energy rays include ultraviolet rays, far ultraviolet rays, EB, EUV rays with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation. When ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, or the like is used as the active energy ray, the exposure dose is preferably 1 to 200 mJ / cm, either directly or using a mask for forming a desired pattern. 2 approximately, more preferably 10 to 100 mJ / cm 2 Irradiate to a degree. When EB is used as the active energy ray, the exposure dose is preferably 0.1 to 1000 μC / cm 2 approximately, more preferably 0.5 to 200 μC / cm 2 The pattern is written directly or using a mask to form the desired pattern. As active energy rays, i-rays with a wavelength of 365 nm, KrF excimer laser light, ArF excimer laser light, EB, EUV, X-rays, soft X-rays, γ-rays, and synchrotron radiation are suitable for fine patterning, with EB and EUV being more suitable for fine patterning.

[0114] After exposure to active energy rays, post-exposure baking (PEB) may be performed on a hot plate or in an oven, preferably at 50 to 150° C. for 10 seconds to 30 minutes, more preferably at 60 to 120° C. for 30 seconds to 20 minutes.

[0115] [Development process] After exposure or PEB, the exposed resist film is developed using an alkaline aqueous solution or an organic solvent developer for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, by a conventional method such as dipping, puddling, or spraying, to form the desired pattern. In the case of a positive resist composition, the irradiated portions dissolve in the developer, while the unexposed portions do not dissolve, forming a desired positive pattern on the substrate. In the case of a negative resist composition, the opposite is true to the case of a positive resist material; the irradiated portions become insoluble in the developer, while the unexposed portions dissolve.

[0116] Examples of aqueous alkaline developer solutions include 0.1 to 10% by mass, preferably 2 to 5% by mass, of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), and the like. Examples of organic solvent developers include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, Examples of the developer include methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These developers may be used alone or in combination of two or more.

[0117] After development is completed, rinsing is carried out. Examples of solvents that can be used for rinsing include water, alcohols having 3 to 10 carbon atoms, ether compounds having 8 to 12 carbon atoms, alkanes, alkenes, alkynes having 6 to 12 carbon atoms, and aromatic solvents. Rinsing can reduce the occurrence of resist pattern collapse and defects. Rinsing is not always necessary, and not performing rinsing can reduce the amount of solvent used.

[0118] The developed hole or trench pattern can also be shrunk using thermal flow, RELACS, or DSA. A shrink agent is applied to the hole pattern, and the diffusion of an acid catalyst from the resist film during baking causes crosslinking of the shrink agent on the surface of the resist film, resulting in adhesion of the shrink agent to the sidewalls of the hole pattern. The baking temperature is preferably 70 to 180°C, more preferably 80 to 170°C, and the baking time is preferably 10 to 300 seconds. Excess shrink agent is removed, and the hole pattern is shrunk. [Example]

[0119] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples. The main raw materials used in the examples are as follows:

[0120] [Main raw materials] 2,3,4,6-Tetraiodobenzoic acid: Synthesized according to the method described in Austrian Patent No. 209897. (See chemical formula (II)) 25% tetramethylammonium hydroxide aqueous solution: manufactured by Tokyo Chemical Industry Co., Ltd. (See chemical formula (III-1-6)). 40% benzyltrimethylammonium hydroxide methanol solution: manufactured by Tokyo Chemical Industry Co., Ltd. (See chemical formula (III-1-23)). Triphenylsulfonium chloride: Manufactured by Fujifilm Wako Pure Chemical Industries. (See chemical formula (III-2-1)) Diphenyliodonium chloride: manufactured by Tokyo Chemical Industry Co., Ltd. (See chemical formula (III-4-1)).

[0121] Example 1 <Synthesis of tetramethylammonium 2,3,4,6-tetraiodobenzoate> A 100 ml three-necked flask was charged with 6.26 g (10.0 mmol) of 2,3,4,6-tetraiodobenzoic acid and 20.00 g of tetrahydrofuran, and then 4.01 g (11.0 mmol) of 25% aqueous tetramethylammonium hydroxide solution was added dropwise and stirred at room temperature for 1 hour. The precipitated crystals were then filtered to obtain 3.63 g of pale brown crystals (yield: 52%).

[0122] This light brown crystal 1 The H-NMR spectrum data was as follows: 1 H-NMR (d6-DMSO) δ: 8.13(s, 1H), 3.11(s, 12H). From this spectral data, the obtained light brown crystals were identified as the title compound represented by chemical formula (I-1-2). This compound is designated as "PDB1."

[0123] Example 2 <Synthesis of benzyltrimethylammonium 2,3,4,6-tetraiodobenzoate> A 100 ml three-necked flask was charged with 6.26 g (10.0 mmol) of 2,3,4,6-tetraiodobenzoic acid and 40.00 g of 2-propanol, and then 4.18 g (10.0 mmol) of 40% benzyltrimethylammonium hydroxide in methanol was added dropwise and stirred at room temperature for 2 hours. The precipitated crystals were then filtered to obtain 1.26 g of pale yellow crystals (yield: 16%).

[0124] This pale yellow crystal 1 The H-NMR spectrum data was as follows: 1 H-NMR (d6-DMSO) δ: 8.13(s, 1H), 7.61-7.45(m, 5H), 4.55(s, 2H), 3.04(s, 9H). From this spectral data, the obtained pale yellow crystals were identified as the title compound represented by chemical formula (I-1-18). This compound is designated as "PDB2."

[0125] Example 3 <Synthesis of triphenylsulfonium 2,3,4,6-tetraiodobenzoate> A 50 mL three-necked flask was charged with 0.77 g (1.0 mmol) of benzyltrimethylammonium 2,3,4,6-tetraiodobenzoate, 0.30 g (1.0 mmol) of triphenylsulfonium chloride, and 5.00 g of water, and the mixture was stirred at room temperature for 2 hours. The precipitated crystals were then filtered to obtain 0.41 g of white crystals (yield: 46%).

[0126] This white crystal 1 The H-NMR spectrum data was as follows: 1 H-NMR (d6-DMSO) δ: 8.15(s, 1H), 7.94-7.69(m, 15H). From this spectral data, the obtained white crystals were identified as the title compound represented by chemical formula (I-2-1). This compound is designated as "PDB3."

[0127] Example 4 <Synthesis of diphenyliodonium 2,3,4,6-tetraiodobenzoate> A 200 mL three-necked flask was charged with 0.70 g (1.0 mmol) of tetramethylammonium 2,3,4,6-tetraiodobenzoate, 0.35 g (1.1 mmol) of diphenyliodonium chloride, 5.00 g of chloroform, and 5.00 g of water, and the mixture was stirred at room temperature for 1 hour. The precipitated crystals were then filtered to obtain 0.42 g of white crystals (yield: 46%).

[0128] This white crystal 1 The H-NMR spectrum data was as follows: 1 H-NMR (d6-DMSO) δ: 8.19 (d, 4H), 8.13 (s, 1H), 7.61 (t, 2H), 7.48 (t, 4H). From this spectral data, the obtained white crystals were identified as the title compound represented by chemical formula (I-4-1).

[0129] [Examples 5 and 6 and Comparative Example 1] Preparation of resist composition The main raw materials listed below were mixed in the proportions shown in Table 1 to prepare a uniform solution, which was then filtered through a membrane filter with a pore size of 0.2 μm to prepare resist compositions (Examples 5 and 6 and Comparative Example 1).

[0130] [Main raw materials] (A) Polymer having a structural unit containing an acid-reactive group Copolymer of 4-hydroxystyrene and 1-ethylcyclopentyl methacrylate: Synthesized according to the method described in JP 2021-196578 A (hereinafter sometimes referred to as "Polymer 1"). (B) Photoacid generator Triphenylsulfonium triflate salt: manufactured by Tokyo Chemical Industry Co., Ltd. (hereinafter referred to as "PAG1") (C) Acid diffusion controller Tetramethylammonium 2,3,4,6-tetraiodobenzoate: Compound of Example 1 (PDB1) Benzyltrimethylammonium 2,3,4,6-tetraiodobenzoate: Compound of Example 2 (PDB2) Benzyltrimethylammonium 2,3,5-triiodobenzoate: Synthesized according to the method described in JP 2023-62885 A (hereinafter sometimes referred to as "PDB4"). (D) Solvent Propylene glycol monomethyl ether acetate: Kanto Chemical Co., Ltd. (hereinafter referred to as "PGMEA") γ-Butyrolactone: manufactured by Kanto Chemical (hereinafter referred to as "GBL")

[0131] [Test Example 1] Evaluation of sensitivity The resist compositions (Examples 5 and 6 and Comparative Example 1) were evaluated for sensitivity as follows. (1) The resist composition was applied to a 2 cm square silicon substrate using a spin coater, and a pre-baked (PAB) process was performed on a hot plate at 110°C for 90 seconds to form a resist film with a thickness of 50 nm. (2) The formed resist film was exposed to light using an electron beam lithography system (ELS-7500EX manufactured by Elionix) by gradually changing the exposure dose so that a line and space pattern (half pitch 100 nm) would be formed after development. (3) After exposure, the substrate was subjected to post-exposure baking (PEB) at 110° C. for 90 seconds. (4) After the PEB treatment, the substrate was subjected to alkaline development for 60 seconds at 25° C. using a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution ("NMD-3" manufactured by Tokyo Ohka Kogyo Co., Ltd.). (5) After the alkaline development, the substrate was washed with pure water for 15 seconds to obtain a substrate (test piece) on which a resist pattern was formed. (6) The resist pattern of the obtained test piece was observed with a scanning electron microscope (Hitachi High-Technologies Corporation, "S-4800") to confirm the exposure dose required to obtain a line and space pattern with a half pitch of 100 nm. The lower the exposure dose, the higher the sensitivity.

[0132] The sensitivity evaluation results are shown in Table 1.

[0133] [Table 1]

[0134] The results in Table 1 show that the resist compositions (Examples 5 and 6) containing the compounds of the present invention (PDB1 and 2) form resist patterns with lower exposure doses than the resist composition (Comparative Example 1) containing the conventional compound (PDB4), indicating that the compounds of the present invention (PDB1 and 2) exhibit higher sensitivity to actinic rays than the conventional compound (PDB4).

[0135] [Example 7 and Comparative Example 2] Preparation of resist composition The main raw materials listed below were mixed in the proportions shown in Table 2 to prepare a uniform solution, which was then filtered through a membrane filter with a pore size of 0.2 μm to prepare resist compositions (Example 7 and Comparative Example 2).

[0136] [Main raw materials] (A) Polymer having a structural unit containing an acid-reactive group Copolymer of 4-hydroxystyrene and 1-ethylcyclopentyl methacrylate: Synthesized according to the method described in JP 2021-196578 A (hereinafter sometimes referred to as "Polymer 1"). (B) Photoacid generator Triphenylsulfonium triflate salt: manufactured by Tokyo Chemical Industry Co., Ltd. (hereinafter referred to as "PAG1") (C) Acid diffusion controller Triphenylsulfonium 2,3,4,6-tetraiodobenzoate: the compound of Example 3 (PDB3) Triphenylsulfonium 2,3,5-triiodobenzoate: Synthesized according to the method described in JP 2023-62885 A (hereinafter sometimes referred to as "PDB5"). (D) Solvent Propylene glycol monomethyl ether acetate: Kanto Chemical Co., Ltd. (hereinafter referred to as "PGMEA") γ-Butyrolactone: manufactured by Kanto Chemical (hereinafter referred to as "GBL")

[0137] [Test Example 2] Evaluation of sensitivity The resist compositions (Example 7 and Comparative Example 2) were evaluated for sensitivity as follows. (1) The resist composition was applied to a 2 cm square silicon substrate using a spin coater, and a pre-baked (PAB) process was performed on a hot plate at 110°C for 90 seconds to form a resist film with a thickness of 50 nm. (2) The formed resist film was exposed to light using an electron beam lithography system (ELS-7500EX manufactured by Elionix) by gradually changing the exposure dose so that a line and space pattern (half pitch 100 nm) would be formed after development. (3) After exposure, the substrate was subjected to post-exposure baking (PEB) at 110° C. for 90 seconds. (4) After the PEB treatment, the substrate was subjected to alkaline development for 60 seconds at 25° C. using a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution ("NMD-3" manufactured by Tokyo Ohka Kogyo Co., Ltd.). (5) After the alkaline development, the substrate was washed with pure water for 15 seconds to obtain a substrate (test piece) on which a resist pattern was formed. (6) The resist pattern of the obtained test piece was observed with a scanning electron microscope (Hitachi High-Technologies Corporation, "S-4800") to confirm the exposure dose required to obtain a line and space pattern with a half pitch of 100 nm. The lower the exposure dose, the higher the sensitivity.

[0138] The sensitivity evaluation results are shown in Table 2.

[0139] [Table 2]

[0140] The results in Table 2 show that the resist composition containing the compound of the present invention (PDB3) (Example 7) forms a resist pattern with a lower exposure dose than the resist composition containing the conventional compound (PDB5) (Comparative Example 2), indicating that the compound of the present invention (PDB3) exhibits higher sensitivity to actinic rays than the conventional compound (PDB5). [Industrial Applicability]

[0141] The compound of the present invention represented by chemical formula (I) has a 2,3,4,6-tetraiodobenzoate anion in the molecule, and therefore has excellent compatibility with resins, solvents, etc., and also has high photosensitivity to actinic energy rays such as EUV (extreme ultraviolet light), EB (electron beam), X-rays, etc. Therefore, the compound of the present invention is useful as an acid diffusion controller with high photodecomposition efficiency.

Claims

1. A compound represented by chemical formula (I): 【Chemistry 1】 (In the formula, [A] ＋ represents a monovalent counter cation represented by formula (1) to formula (4). 【Chemistry 2】 (In the formula, R １ａ ~R １ｄ are the same or different and represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a phenyl group, or an aralkyl group. ２ａ ~R ２ｃ , R ３ａ ~R ３ｃ are the same or different and represent a hydrogen atom, a halogen atom, or —CF ３ , -SO ２ R ５ , -SF ５ , -CHR １１ CH ２ X １ , an alkyl group having 1 to 10 carbon atoms, —OR １１ , -COOH, -NO ２ , a polymerizable group, or an acid-reactive group. ４ａ and R ４ｂ are the same or different and represent a hydrogen atom, a halogen atom, or —CF ３ , -SO ２ R ６ , -SF ５ , -CHR １１ CH ２ X １ , an alkyl group having 1 to 10 carbon atoms, —OR １１ , -COOH, -NO ２ , a polymerizable group, or an acid-reactive group. ５ is -CF ３ , -CF ２ CF ３ , an alkyl group having 1 to 10 carbon atoms, or a phenyl group. ６ represents an alkyl group having 1 to 10 carbon atoms or a phenyl group. １１ represents a hydrogen atom or a methyl group, and X １ represents a halogen atom, a mesyloxy group (OMs), a tosyloxy group (OTs), or a trifluoromethanesulfonyloxy group (OTf). １ represents a single bond, —O—, —S—, —S(O)— or —S(O) ２ m1 to m3 represent an integer of 0 to 5. p1 represents an integer of 0 to 5. p2 and p3 represent an integer of 0 to 4. q1 and q2 represent an integer of 0 to 5. When m1 is an integer of 2 to 5, a plurality of R ２ａ may be the same or different, and when m2 is an integer of 2 to 5, a plurality of R ２ｂ may be the same or different, and when m3 is an integer of 2 to 5, a plurality of R ２ｃ When p1 is an integer of 2 to 5, a plurality of R ３ａ may be the same or different, and when p2 is an integer of 2 to 4, a plurality of R ３ｂ may be the same or different, and when p3 is an integer of 2 to 4, a plurality of R ３ｃ When q1 is an integer of 2 to 5, a plurality of R ４ａ may be the same or different, and when q2 is an integer of 2 to 5, a plurality of R ４ｂ may be the same or different.)

2. An acid diffusion controller comprising the compound according to claim 1.

3. A resist composition comprising a polymer having a structural unit containing an acid-reactive group and the compound according to claim 1.

4. A method for forming a resist pattern, comprising: A step of applying the resist composition according to claim 3 to a substrate to form a resist film; exposing the resist film to light; developing the exposed resist film to form a resist pattern; A forming method comprising:

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