Chemically amplified positive-type resist material and pattern formation method

Abstract

To provide a positive resist material that has controlled acid diffusion, a resolution surpassing that of a conventional positive resist material, reduced edge roughness or dimensional variation, and a good pattern profile after exposure, and a pattern forming process.SOLUTION: A positive resist material comprises a base polymer end-capped with a salt comprising an ammonium cation linked to a sulfide group and a fluorinated anion.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a positive-type resist material and a pattern forming method. [Background technology]

[0002] With the increasing integration and speed of LSIs, the miniaturization of pattern rules is progressing rapidly. This is because the proliferation of 5G high-speed communication and artificial intelligence (AI) necessitates high-performance devices to process them. As a cutting-edge miniaturization technology, mass production of 5nm node devices is underway using extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm. Furthermore, research using EUV lithography is progressing for next-generation 3nm node and the following-generation 2nm node devices.

[0003] As miniaturization progresses, image blurring due to acid diffusion is becoming a problem. To ensure resolution in fine patterns with dimensions of 45 nm or larger, it has been suggested that controlling acid diffusion is important, in addition to improving dissolution contrast as has been conventionally proposed (Non-Patent Literature 1). However, since chemically amplified resist materials increase sensitivity and contrast through acid diffusion, attempting to suppress acid diffusion to the extreme by lowering the post-exposure bake (PEB) temperature or shortening the time results in a significant decrease in sensitivity and contrast.

[0004] Adding an acid generator that produces bulky acids is effective in suppressing acid diffusion. Therefore, it has been proposed to include repeating units derived from onium salts having polymerizable unsaturated bonds in the polymer. In this case, the polymer also functions as an acid generator (polymer-bound type acid generator). Patent Document 1 proposes sulfonium salts and iodonium salts having polymerizable unsaturated bonds that generate specific sulfonic acids. Patent Document 2 proposes sulfonium salts in which sulfonic acids are directly linked to the main chain.

[0005] Resist materials with modified polymer ends have been proposed. These include a resist material in which an acid-unstable group is attached to the end of a living anionic polymer using an alkyllithium initiator (Patent Document 3), a resist material in which a sulfonium salt acting as an acid generator for fluorosulfonic acid is attached to the polymer end in a living radical polymerization (RAFT) (Patent Document 4), and a resist material in which an acid generator is attached to both ends of a polymer by polymerization using an azo polymerization initiator with sulfonium salts acting as acid generators for fluorosulfonic acid attached to both sides (Patent Document 5). However, polymers with acid generators attached to the ends have the disadvantage that acid diffusion increases because the ends are more mobile.

[0006] A resist material using a polymer with amino groups attached to its ends has been proposed (Patent Document 6). The amino groups at the polymer ends act as quenchers and do not swell in the developer solution, but hydrogen bonding of the amino groups causes aggregation of the polymer, resulting in uneven diffusion of the acid, which degrades the edge roughness. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2006-045311 [Patent Document 2] Japanese Patent Publication No. 2006-178317 [Patent Document 3] Patent No. 4132783 [Patent Document 4] Japanese Patent Publication No. 2014-65896 [Patent Document 5] Japanese Patent Publication No. 2013-1850 [Patent Document 6] Japanese Patent Publication No. 2003-301006 [Non-patent literature]

[0008] [Non-Patent Document 1] SPIE Vol. 3331 p531 (1998) [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention has been made in view of the above circumstances, and aims to provide a positive-type resist material and a pattern forming method in which acid diffusion is controlled, resolution is superior to that of conventional positive-type resist materials, edge roughness and dimensional variation are small, and the pattern shape after exposure is good. [Means for solving the problem]

[0010] The inventors of this invention have diligently studied to obtain a positive resist material that meets the recent demand for high resolution and low edge roughness and dimensional variation. As a result, they discovered that it is necessary to minimize the acid diffusion distance and suppress swelling in alkaline developer. They found that by attaching an ammonium salt, which acts as a quencher, to the ends of the polymer, acid diffusion can be reduced to the greatest extent possible, thus reducing swelling. They also found that by using a salt with an acid containing fluorine atoms to prevent aggregation of amino groups, aggregation is prevented by the electrical repulsion of the fluorine atoms, thereby homogenizing acid diffusion and improving edge roughness and dimensional uniformity (CDU). This is particularly effective when used as a base polymer for chemically amplified positive resist materials.

[0011] Furthermore, in order to improve the dissolution contrast, we discovered that by introducing repeating units in which hydrogen atoms of carboxyl groups or phenolic hydroxyl groups are substituted with acid-unstable groups into the base polymer, the contrast of the alkali dissolution rate before and after exposure is significantly increased, the effect of suppressing acid diffusion is enhanced, high resolution is obtained, and the pattern shape, edge roughness, and CDU after exposure are good, resulting in a positive-type resist material that is particularly suitable for ultra-large-scale integrated circuit (ULSI) manufacturing or as a fine pattern formation material for photomasks, thus completing the present invention.

[0012] In other words, the present invention provides the following positive-type resist material and pattern formation method. 1. A positive resist material comprising a base polymer having a terminal sealed with a salt composed of an ammonium cation linked to a sulfide group and an anion containing a fluorine atom. 2. The positive resist material according to 1, wherein the terminal structure is represented by the following formula (a). [Chemical formula] (In the formula, X 1 is a hydrocarbylene group having 1 to 20 carbon atoms, and the hydrocarbylene group may contain at least one selected from a hydroxy group, an ether bond, an ester bond, a carbonate bond, a urethane bond, a lactone ring, a sultone ring, and a halogen atom. R 1 to R 3 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 24 carbon atoms, and the hydrocarbyl group may contain at least one selected from a halogen atom, a hydroxy group, a carboxy group, an ether bond, an ester bond, a thioether bond, a thioester bond, a thionoester bond, a dithioester bond, an amino group, a hydrazide group, a nitro group, and a cyano group. X 1 and R 1 to R 3 Among them, at least two may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and R 1 and R 2 may combine to form =C(R 1A )(R 2A ). R 1A and R 2A are each independently a hydrogen atom or a hydrocarbyl group having 1 to 16 carbon atoms, and the hydrocarbyl group may contain an oxygen atom, a sulfur atom, or a nitrogen atom. Also, R 2A and R 3 may combine to form a ring together with the carbon atom and the nitrogen atom to which they are bonded, and the ring may contain a double bond, an oxygen atom, a sulfur atom, or a nitrogen atom. Mq -These are carboxylic acid anions having a fluorine atom, phenoxide anions having a fluorine atom, sulfonamide anions having a fluorine atom, 1,1,1,3,3,3-hexafluoro-2-propoxide anions having a fluorine atom, 1,3-diketone anions having a fluorine atom, β-ketoester anions having a fluorine atom, or imide anions having a fluorine atom. The dashed lines represent connections. 3. A positive-type resist material of type 1 or 2, wherein the carboxylic acid anion having a fluorine atom is represented by the following formula (a)-1, the phenoxide anion having a fluorine atom is represented by the following formula (a)-2, the sulfonamide anion having a fluorine atom is represented by the following formula (a)-3, the 1,1,1,3,3,3-hexafluoro-2-propoxide anion having a fluorine atom is represented by the following formula (a)-4, and the 1,3-diketone anion, β-ketoester anion, or imide anion having a fluorine atom is represented by the following formula (a)-5. [ka] (In the formula, R 4 and R 6 Each of these is independently a fluorine atom or a fluorinated hydrocarbyl group having 1 to 30 carbon atoms, and the fluorinated hydrocarbyl group may contain at least one selected from an ester bond, a lactone ring, an ether bond, a carbonate bond, a thioether bond, a hydroxyl group, an amino group, a nitro group, a cyano group, a sulfo group, a sulfonic acid ester bond, a chlorine atom, and a bromine atom. Rf is a fluorine atom, a trifluoromethyl group, or a 1,1,1-trifluoro-2-propanol group. R 5 These are a chlorine atom, a bromine atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbyloxycarbonyl group having 2 to 6 carbon atoms, a cyano group, an amino group, or a nitro group. R 7This is a hydrocarbyl group having 1 to 30 carbon atoms, which may contain a hydrogen atom or a heteroatom. R 8 This is a trifluoromethyl group, a C1-C20 hydrocarbyloxy group, or a C2-C21 hydrocarbyloxycarbonyl group, and the hydrocarbyl portion of the hydrocarbyloxy group or hydrocarbyloxycarbonyl group may contain at least one selected from a carbonyl group, an ether bond, an ester bond, a thiol group, a cyano group, a nitro group, a hydroxyl group, a sultone group, a sulfonic acid ester bond, an amide bond, and a halogen atom. R 9 and R 10 Each of these is independently an alkyl group or phenyl group having 1 to 10 carbon atoms, and R 9 and R 10 One or more of the hydrogen atoms in one or both of the atoms are substituted with fluorine atoms. X is either -C(H)= or -N=. m and n are integers satisfying 1 ≤ m ≤ 5, 0 ≤ n ≤ 3, and 1 ≤ m + n ≤ 5. 4. A positive-type resist material according to any one of 1 to 3, wherein the base polymer comprises a base polymer containing a repeating unit b1 in which a hydrogen atom of a carboxyl group is substituted with an acid-unstable group, or a repeating unit b2 in which a hydrogen atom of a phenolic hydroxyl group is substituted with an acid-unstable group. 5. A positive-type resist material of type 4, wherein the repeating unit b1 is represented by the following formula (b1) and the repeating unit b2 is represented by the following formula (b2). [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. Y 1 This is a linking group having 1 to 12 carbon atoms that includes a single bond, a phenylene group or a naphthylene group, or at least one selected from an ester bond, an ether bond, and a lactone ring. Y 2 These are single bonds, ester bonds, or amide bonds. Y 3These are single bonds, ether bonds, or ester bonds. R 11 and R 12 These are, independently, acid-unstable groups. R 13 This is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R 14 This is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may contain an ether bond or an ester bond. a is either 1 or 2. b is an integer between 0 and 4, where 1 ≤ a + b ≤ 5. 6. A positive-type resist material according to any one of 1 to 5, wherein the base polymer further comprises repeating units c containing adhesive groups selected from hydroxyl groups, carboxyl groups, lactone rings, carbonate bonds, thiocarbonate bonds, carbonyl groups, cyclic acetal groups, ether bonds, ester bonds, sulfonic acid ester bonds, cyano groups, amide bonds, -OC(=O)-S-, and -OC(=O)-NH-. 7. A positive-type resist material according to any of 1 to 6, wherein the base polymer further comprises repeating units represented by any of the following formulas (d1) to (d3). [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. Z 1 This refers to a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, or -OZ 11 -, -C(=O)-OZ 11 -or -C(=O)-NH-Z 11 - is Z 11 This refers to an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z 2These are single bonds or ester bonds. Z 3 This is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -OC(=O)- Z 31 This refers to an aliphatic hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, a bromine atom, or an iodine atom. Z 4 This group is a methylene group, a 2,2,2-trifluoro-1,1-ethanediyl group, or a carbonyl group. Z 5 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, phenylene groups substituted with trifluoromethyl groups, -OZ 51 -, -C(=O)-OZ 51 -or -C(=O)-NH-Z 51 - is Z 51 This is a phenylene group substituted with an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, a halogen atom, or a hydroxyl group. R 21 ~R 28 Each of these is independently a C1-C20 hydrocarbyl group which may contain a halogen atom or a heteroatom. 23 and R 24 or R 26 and R 27 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. M - (It is a non-nucleophilic counterion.) 8. Furthermore, any of the positive-type resist materials 1 to 7 containing an acid generator. 9. Furthermore, any of the positive-type resist materials 1 to 8 containing an organic solvent. 10. In addition, one of the positive-type resist materials 1-9, including a quencher. 11. Furthermore, any of the positive-type resist materials 1 to 10 containing a surfactant. A pattern formation method comprising the steps of: forming a resist film on a substrate using any of the positive-type resist materials from 12.1 to 11; exposing the resist film with high-energy rays; and developing the exposed resist film using a developer. 13. Pattern formation method 12 wherein the high-energy beam is an i-line, KrF excimer laser light, ArF excimer laser light, electron beam (EB), or EUV with a wavelength of 3 to 15 nm. [Effects of the Invention]

[0013] The positive-type resist material of the present invention exhibits a high effect in suppressing acid diffusion, high contrast in alkali dissolution rates before and after exposure when formed as a resist film, high resolution, and good pattern shape, edge roughness, and CDU after exposure. Therefore, due to these excellent properties, it is extremely practical and is particularly useful as a material for forming fine patterns in photomasks for ultra-large-scale integrated circuit (ULSI) manufacturing or EB lithography, and as a pattern-forming material for EB or EUV lithography. The positive-type resist material of the present invention can be applied not only to lithography in semiconductor circuit formation, but also to the formation of mask circuit patterns, micromachines, and thin-film magnetic head circuits. [Modes for carrying out the invention]

[0014] [Base polymer] The positive-type resist material of the present invention is characterized by comprising a base polymer whose ends are sealed with a salt consisting of an ammonium cation linked to a sulfide group and an anion containing a fluorine atom.

[0015] The terminal structure (hereinafter also referred to as terminal structure a) is preferably a structure represented by the following formula (a). [ka] (In the equation, dashed lines represent connections.)

[0016] In formula (a), X 1 The group is a hydrocarbylene group having 1 to 20 carbon atoms, and the hydrocarbylene group may contain at least one selected from a hydroxyl group, an ether bond, an ester bond, a carbonate bond, a urethane bond, a lactone ring, a sultone ring, and a halogen atom. The hydrocarbylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, etc. Examples include alkanediyl groups with 1 to 20 carbon atoms; cyclic saturated hydrocarbylene groups with 3 to 20 carbon atoms such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, and adamantanediyl; unsaturated aliphatic hydrocarbylene groups with 2 to 20 carbon atoms such as vinylene and propene-1,3-diyl; arylene groups with 6 to 20 carbon atoms such as phenylene and naphthylene; and groups obtained by combining these.

[0017] In formula (a), R 1 ~R 3Each of these is independently a hydrogen atom or a C1-C24 hydrocarbyl group, and the hydrocarbyl group may contain at least one selected from a halogen atom, a hydroxyl group, a carboxyl group, an ether bond, an ester bond, a thioether bond, a thioester bond, a thionoester bond, a dithioester bond, an amino group, a hydrazide group, a nitro group, and a cyano group. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C20 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl; C3-C20 cyclic saturated hydrocarbyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; C2-C20 alkenyl groups such as vinyl, propenyl, butenyl, and hexenyl; and ethynyl and propinyl groups. Examples include alkynyl groups with 2 to 20 carbon atoms, such as yl group, butynyl group, 2-cyclohexylethynyl group, and 2-phenylethynyl group; cyclic unsaturated aliphatic hydrocarbyl groups with 3 to 20 carbon atoms, such as cyclohexenyl group and norbornenyl group; aryl groups with 6 to 20 carbon atoms, such as phenyl group, methylphenyl group, ethylphenyl group, n-propylphenyl group, isopropylphenyl group, n-butylphenyl group, isobutylphenyl group, sec-butylphenyl group, tert-butylphenyl group, naphthyl group, methylnaphthyl group, ethylnaphthyl group, n-propylnaphthyl group, isopropylnaphthyl group, n-butylnaphthyl group, isobutylnaphthyl group, sec-butylnaphthyl group, and tert-butylnaphthyl group; and aralkyl groups with 7 to 20 carbon atoms, such as benzyl group and phenethyl group.

[0018] Also, X 1 and R 1 ~R 3At least two of these may bond to each other to form a ring with the nitrogen atom to which they are bonded, 1 and R 2 When combined, =C(R 1A )(R 2A ) may be formed. 1A and R 2A Each of these is independently a hydrogen atom or a hydrocarbyl group having 1 to 16 carbon atoms, and the hydrocarbyl group may contain an oxygen atom, a sulfur atom, or a nitrogen atom. Examples of the hydrocarbyl group are the same as those described above. Also, R 2A and R 3 These atoms may bond with each other to form a ring with the carbon and nitrogen atoms to which they are bonded, and this ring may contain a double bond, an oxygen atom, a sulfur atom, or a nitrogen atom.

[0019] To attach a salt consisting of an ammonium cation linked to a sulfide group and an anion containing a fluorine atom to the polymer ends, for example, a compound represented by the following formula (a1) can be used as a chain transfer agent, and this can be added to the polymerization solution before or during polymerization to carry out the polymerization reaction. Radicals are generated by the decomposition of the polymerization initiator, and polymerization begins by the chain transfer of radicals to thiols, producing a polymer whose ends are sealed with the aforementioned salt. [ka] (In the formula, X 1 and R 1 ~R 3 This is the same as above. MQ - (This will be explained later.)

[0020] Examples of cations of the compound represented by formula (a1) include, but are not limited to, those listed below. [ka]

[0021] [ka]

[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0033] [ka]

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[0038] [ka]

[0039] In formula (a), Mq - These are carboxylic acid anions having a fluorine atom, phenoxide anions having a fluorine atom, sulfonamide anions having a fluorine atom, 1,1,1,3,3,3-hexafluoro-2-propoxide anions having a fluorine atom, 1,3-diketone anions having a fluorine atom, β-ketoester anions having a fluorine atom, or imide anions having a fluorine atom.

[0040] The carboxylic acid anion having a fluorine atom is preferably represented by the following formula (a)-1, the phenoxide anion having a fluorine atom is preferably represented by the following formula (a)-2, the sulfonamide anion having a fluorine atom is preferably represented by the following formula (a)-3, the 1,1,1,3,3,3-hexafluoro-2-propoxide anion having a fluorine atom is preferably represented by the following formula (a)-4, and the 1,3-diketone anion, β-ketoester anion, or imide anion having a fluorine atom is preferably represented by the following formula (a)-5. [ka]

[0041] In equations (a)-1 and (a)-3, R 4 and R 6 Each of these is independently either a fluorine atom or a fluorinated hydrocarbyl group having 1 to 30 carbon atoms. The fluorinated hydrocarbyl group having 1 to 30 carbon atoms is a group in which at least one hydrogen atom of a hydrocarbyl group having 1 to 30 carbon atoms is substituted with a fluorine atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 30 carbon atoms, cyclic saturated hydrocarbyl groups having 3 to 30 carbon atoms, alkenyl groups having 2 to 30 carbon atoms, alkynyl groups having 2 to 30 carbon atoms, cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 30 carbon atoms, aryl groups having 6 to 30 carbon atoms, aralkyl groups having 7 to 30 carbon atoms, and groups obtained by combining these. The fluorinated hydrocarbyl group may contain at least one selected from an ester bond, a lactone ring, an ether bond, a carbonate bond, a thioether bond, a hydroxyl group, an amino group, a nitro group, a cyano group, a sulfo group, a sulfonic acid ester bond, a chlorine atom, and a bromine atom.

[0042] In formula (a)-2, Rf is a fluorine atom, a trifluoromethyl group, or a 1,1,1-trifluoro-2-propanol group.

[0043] In formula (a)-2, R 5 The group is a chlorine atom, a bromine atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbyloxycarbonyl group having 2 to 6 carbon atoms, a cyano group, an amino group, or a nitro group. m and n are integers satisfying 1 ≤ m ≤ 5, 0 ≤ n ≤ 3, and 1 ≤ m + n ≤ 5.

[0044] In formula (a)-3, R 7 This is a C1-C30 hydrocarbyl group which may contain a hydrogen atom or a heteroatom. The C1-C30 hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C30 alkyl groups, C3-C30 cyclic saturated hydrocarbyl groups, C2-C30 alkenyl groups, C2-C30 alkynyl groups, C3-C30 cyclic unsaturated aliphatic hydrocarbyl groups, C6-C30 aryl groups, C7-C30 aralkyl groups, and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, nitrogen atom, or halogen atom, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, or nitrogen atom, and as a result, it may contain ester bonds, ether bonds, thioether bonds, carbonyl groups, sulfonyl groups, carbonate bonds, carbamate groups, sulfo groups, amino groups, amide bonds, hydroxyl groups, thiol groups, nitro groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0045] In formula (a)-4, R 8 This is a trifluoromethyl group, a C1-C20 hydrocarbyloxy group, or a C2-C21 hydrocarbyloxycarbonyl group, and the hydrocarbyl portion of the hydrocarbyloxy group or hydrocarbyloxycarbonyl group may contain at least one selected from a carbonyl group, an ether bond, an ester bond, a thiol group, a cyano group, a nitro group, a hydroxyl group, a sultone group, a sulfonic acid ester bond, an amide bond, and a halogen atom.

[0046] R 8The hydrocarbyl portion of the hydrocarbyloxy group or hydrocarbyloxycarbonyl group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, 3-pentyl, tert-pentyl, neopentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl groups. Groups; cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, cyclopropylmethyl group, cyclopropylethyl group, cyclobutylmethyl group, cyclobutylethyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclohexylmethyl group, cyclohexylethyl group, methylcyclopropyl group, methylcyclobutyl group, methylcyclopentyl group, methylcyclohexyl group, ethylcyclopropyl group, ethylcyclobutyl group, ethylcyclopentyl group, Cyclic saturated hydrocarbyl groups with 3 to 20 carbon atoms, such as ethylcyclohexyl group; vinyl group, 1-propenyl group, 2-propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, eicocenyl group, and other alkenyl groups with 2 to 20 carbon atoms; ethinyl group, propynyl group, butynyl group, pentynyl group, hexynyl group, hep Alkynyl groups with 2 to 20 carbon atoms, such as thynyl, octinyl, noninyl, desinyl, undecinyl, dodecinyl, tridecinyl, tetradecinyl, pentadecinyl, hexadesinyl, heptadecinyl, octadecinyl, nonadesinyl, and icosinyl; cyclic unsaturated aliphatic hydrocarbyl groups with 3 to 20 carbon atoms, such as cyclopentenyl, cyclohexenyl, methylcyclopentenyl, methylcyclohexenyl, ethylcyclopentenyl, ethylcyclohexenyl, and norbornenyl;Examples include aryl groups with 6 to 20 carbon atoms, such as phenyl group, methylphenyl group, ethylphenyl group, n-propylphenyl group, isopropylphenyl group, n-butylphenyl group, isobutylphenyl group, sec-butylphenyl group, tert-butylphenyl group, naphthyl group, methylnaphthyl group, ethylnaphthyl group, n-propylnaphthyl group, isopropylnaphthyl group, n-butylnaphthyl group, isobutylnaphthyl group, sec-butylnaphthyl group, and tert-butylnaphthyl group; aralkyl groups with 7 to 20 carbon atoms, such as benzyl group, phenethyl group, phenylpropyl group, phenylbutyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 9-fluorenylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, and 9-fluorenylethyl group; and groups obtained by combining these.

[0047] In formula (a)-5, R 9 and R 10 Each of these is independently an alkyl group or phenyl group having 1 to 10 carbon atoms, and R 9 and R 10 One or more of the hydrogen atoms in one or both of the atoms are replaced by fluorine atoms. X is -C(H)= or -N=.

[0048] Examples of carboxylic acid anions having a fluorine atom include, but are not limited to, those listed below. [ka]

[0049] [ka]

[0050] [ka]

[0051] Examples of phenoxide anions having a fluorine atom include, but are not limited to, those listed below. [ka]

[0052] [ka]

[0053] [ka]

[0054] Examples of sulfonamide anions having a fluorine atom include, but are not limited to, those listed below. [ka]

[0055] [ka]

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[0083] Examples of 1,1,1,3,3,3-hexafluoro-2-propoxide anions having the fluorine atom include, but are not limited to, those listed below. [ka]

[0084] [ka]

[0085] [ka]

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[0090] [ka]

[0091] [ka]

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[0093] Examples of the 1,3-diketone anions, β-ketoester anions, and imide anions having a fluorine atom include, but are not limited to, those listed below. [ka]

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] The compound represented by formula (a1) can be synthesized, for example, by a neutralization reaction between an amine compound linked to a thiol group and an acid containing a fluorine atom.

[0098] The base polymer preferably contains repeating units b1 in which a hydrogen atom of a carboxyl group is substituted with an acid-unstable group, or repeating units b2 in which a hydrogen atom of a phenolic hydroxyl group is substituted with an acid-unstable group.

[0099] Examples of repeating units b1 and b2 include those represented by the following formulas (b1) and (b2), respectively. [ka]

[0100] In equations (b1) and (b2), RA is, independently of each other, a hydrogen atom or a methyl group. Y 1 is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms containing at least one selected from an ester bond, an ether bond and a lactone ring. Y 2 is a single bond, an ester bond or an amide bond. Y 3 is a single bond, an ether bond or an ester bond. R 11 and R 12 are each independently an acid-labile group. R 13 is a fluorine atom, a trifluoromethyl group, a cyano group or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may contain an ether bond or an ester bond. a is 1 or 2. b is an integer of 0 to 4. However, 1 ≦ a + b ≦ 5.

[0101] Examples of the monomer that gives the repeating unit b1 include, but are not limited to, those shown below. In the following formulas, R A and R 11 are the same as described above.

Chemical formula

[0102]

Chemical formula

[0103] Examples of the monomer that gives the repeating unit b2 include, but are not limited to, those shown below. In the following formulas, R A and R 12 are the same as described above.

Chemical formula

[0104] R 11 or R12 Various acid-unstable groups can be selected, but examples include those represented by the following formulas (AL-1) to (AL-3). [ka] (In the equation, dashed lines represent connections.)

[0105] In equation (AL-1), c is an integer between 0 and 6. L1 This refers to a tertiary hydrocarbyl group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms; a trihydrocarbylsilyl group in which each hydrocarbyl group is a saturated hydrocarbyl group having 1 to 6 carbon atoms; a carbonyl group; a saturated hydrocarbyl group having 4 to 20 carbon atoms including an ether bond or an ester bond; or a group represented by formula (AL-3). A tertiary hydrocarbyl group refers to a group obtained by the removal of a hydrogen atom from a tertiary carbon atom of a hydrocarbon.

[0106] R L1 The tertiary hydrocarbyl group represented by can be saturated or unsaturated, and can be branched or cyclic. Specific examples include tert-butyl group, tert-pentyl group, 1,1-diethylpropyl group, 1-ethylcyclopentyl group, 1-butylcyclopentyl group, 1-ethylcyclohexyl group, 1-butylcyclohexyl group, 1-ethyl-2-cyclopentenyl group, 1-ethyl-2-cyclohexenyl group, and 2-methyl-2-adamantyl group. Examples of the trihydrocarbyl silyl group include trimethylsilyl group, triethylsilyl group, and dimethyl-tert-butylsilyl group. The saturated hydrocarbyl group containing the carbonyl group, ether bond, or ester bond may be linear, branched, or cyclic, but cyclic is preferred. Specific examples include 3-oxocyclohexyl group, 4-methyl-2-oxooxan-4-yl group, 5-methyl-2-oxooxolan-5-yl group, 2-tetrahydropyranyl group, and 2-tetrahydrofuranyl group.

[0107] Examples of acid-unstable groups represented by formula (AL-1) include tert-butoxycarbonyl group, tert-butoxycarbonylmethyl group, tert-pentyloxycarbonyl group, tert-pentyloxycarbonylmethyl group, 1,1-diethylpropyloxycarbonyl group, 1,1-diethylpropyloxycarbonylmethyl group, 1-ethylcyclopentyloxycarbonyl group, 1-ethylcyclopentyloxycarbonylmethyl group, 1-ethyl-2-cyclopentenyloxycarbonyl group, 1-ethyl-2-cyclopentenyloxycarbonylmethyl group, 1-ethoxyethoxycarbonylmethyl group, 2-tetrahydropyranyloxycarbonylmethyl group, and 2-tetrahydrofuranyloxycarbonylmethyl group.

[0108] Furthermore, other acid-unstable groups represented by formula (AL-1) include those represented by the following formulas (AL-1)-1 to (AL-1)-10. [ka] (In the equation, dashed lines represent connections.)

[0109] In equations (AL-1)-1 to (AL-1)-10, c is the same as described above. L8 Each of these is independently a saturated hydrocarbyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. L9 R is a hydrogen atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. L10 This is a saturated hydrocarbyl group having 2 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic.

[0110] In formula (AL-2), R L2 and R L3Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic, and specific examples include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, cyclopentyl group, cyclohexyl group, 2-ethylhexyl group, n-octyl group, and the like.

[0111] In formula (AL-2), R L4 This is a hydrocarbyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, which may contain heteroatoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Examples of the hydrocarbyl group include saturated hydrocarbyl groups having 1 to 18 carbon atoms, and some of these hydrogen atoms may be substituted with hydroxyl groups, alkoxy groups, oxo groups, amino groups, alkylamino groups, etc. Examples of such substituted saturated hydrocarbyl groups are shown below. [ka] (In the equation, dashed lines represent connections.)

[0112] R L2 and R L3 And, R L2 and R L4 or R L3 and R L4 These atoms may bond with each other to form a ring together with the carbon atoms to which they are bonded, or together with a carbon atom and an oxygen atom, and in this case, R involved in ring formation L2 and R L3 , R L2 and R L4 , or R L3 and R L4 Each of these is an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10. The number of carbon atoms in the ring obtained by bonding these is preferably 3 to 10, more preferably 4 to 10.

[0113] Among the acid-unstable groups represented by formula (AL-2), those that are linear or branched include, but are not limited to, those represented by formulas (AL-2)-1 to (AL-2)-69 below. In the following formulas, dashed lines represent bonds. [ka]

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] Among the acid-unstable groups represented by formula (AL-2), cyclic groups include tetrahydrofuran-2-yl group, 2-methyltetrahydrofuran-2-yl group, tetrahydropyran-2-yl group, and 2-methyltetrahydropyran-2-yl group.

[0118] Furthermore, examples of acid-unstable groups include groups represented by the following formulas (AL-2a) or (AL-2b). The base polymer may be intermolecularly or intramolecularly crosslinked by these acid-unstable groups. [ka] (In the equation, dashed lines represent connections.)

[0119] In formula (AL-2a) or (AL-2b), R L11 and R L12 Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 8 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic. Also, R L11 and R L12These may bond with each other to form a ring with the carbon atoms to which they are bonded, in which case R L11 and R L12 These are, independently, alkanediyl groups having 1 to 8 carbon atoms. L13 Each of these is independently a saturated hydrocarbylene group having 1 to 10 carbon atoms. The saturated hydrocarbylene group may be linear, branched, or cyclic. Each of d and e is independently an integer from 0 to 10, preferably from 0 to 5, and f is an integer from 1 to 7, preferably from 1 to 3.

[0120] In formula (AL-2a) or (AL-2b), L A This is an aliphatic saturated hydrocarbon group having 1 to 50 carbon atoms with (f+1) valency, an alicyclic saturated hydrocarbon group having 3 to 50 carbon atoms with (f+1) valency, an aromatic hydrocarbon group having 6 to 50 carbon atoms with (f+1) valency, or a heterocyclic group having 3 to 50 carbon atoms with (f+1) valency. Furthermore, some of the -CH2- atoms in these groups may be substituted with a group containing a heteroatom, and some of the hydrogen atoms in these groups may be substituted with a hydroxyl group, a carboxyl group, an acyl group, or a fluorine atom. A Preferred examples include saturated hydrocarbon groups such as saturated hydrocarbylene groups, trivalent saturated hydrocarbon groups, and tetravalent saturated hydrocarbon groups having 1 to 20 carbon atoms, and arylene groups having 6 to 30 carbon atoms. The saturated hydrocarbon groups may be linear, branched, or cyclic. B These are -C(=O)-O-, -NH-C(=O)-O-, or -NH-C(=O)-NH-.

[0121] Examples of crosslinked acetal groups represented by formula (AL-2a) or (AL-2b) include groups represented by the following formulas (AL-2)-70 to (AL-2)-77. [ka] (In the equation, dashed lines represent connections.)

[0122] In formula (AL-3), R L5 , R L6 and R L7Each of these is independently a hydrocarbyl group having 1 to 20 carbon atoms, and may contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbyl groups having 3 to 20 carbon atoms, and aryl groups having 6 to 10 carbon atoms. L5 and R L6 And, R L5 and R L7 or R L6 and R L7 These atoms may bond with each other to form an alicyclic ring with 3 to 20 carbon atoms.

[0123] Examples of groups represented by formula (AL-3) include tert-butyl group, 1,1-diethylpropyl group, 1-ethylnorbonyl group, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-isopropylcyclopentyl group, 1-methylcyclohexyl group, 2-(2-methyl)adamantyl group, 2-(2-ethyl)adamantyl group, and tert-pentyl group.

[0124] In addition, the groups represented by formula (AL-3) include those represented by the following formulas (AL-3)-1 to (AL-3)-19. [ka] (In the equation, dashed lines represent connections.)

[0125] In equations (AL-3)-1 to (AL-3)-19, R L14 Each of these is independently a saturated hydrocarbyl group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms. L15 and R L17 Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 20 carbon atoms. L16This is an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic. Furthermore, a phenyl group is preferred as the aryl group. F is a fluorine atom or a trifluoromethyl group. g is an integer from 1 to 5.

[0126] Furthermore, examples of acid-unstable groups include those represented by the following formulas (AL-3)-20 or (AL-3)-21. The polymer may be intramolecularly or intermolecularly crosslinked by these acid-unstable groups. [ka] (In the equation, dashed lines represent connections.)

[0127] In equations (AL-3)-20 and (AL-3)-21, R L14 The same as above. R L18 h is a saturated hydrocarbylene group with 1 to 20 carbon atoms and a (h+1) valence, or an arylene group with 6 to 20 carbon atoms and a (h+1) valence, and may contain heteroatoms such as oxygen, sulfur, or nitrogen atoms. The saturated hydrocarbylene group may be linear, branched, or cyclic. h is an integer from 1 to 3.

[0128] Examples of monomers that give repeating units containing an acid-unstable group represented by formula (AL-3) include (meth)acrylic acid esters containing the exo-isomer structure represented by the following formula (AL-3)-22. [ka]

[0129] In formula (AL-3)-22, R A The same as above. R Lc1 This is a saturated hydrocarbyl group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms, which may be substituted. The saturated hydrocarbyl group may be linear, branched, or cyclic. Lc2 ~R Lc11Each of these is independently a C1-C15 hydrocarbyl group which may contain a hydrogen atom or a heteroatom. Examples of the heteroatom include an oxygen atom. Examples of the hydrocarbyl group include a C1-C15 alkyl group and a C6-C15 aryl group. Lc2 and R Lc3 And, R Lc4 and R Lc6 And, R Lc4 and R Lc7 And, R Lc5 and R Lc7 And, R Lc5 and R Lc11 And, R Lc6 and R Lc10 And, R Lc8 and R Lc9 or R Lc9 and R Lc10 These are hydrocarbylene groups that may bond with each other to form a ring with the carbon atoms to which they are bonded, and in this case, the groups involved in bonding may include heteroatoms having 1 to 15 carbon atoms. Lc2 and R Lc11 And, R Lc8 and R Lc11 or R Lc4 and R Lc6 This means that adjacent carbon atoms bond to each other without any intervening element, forming a double bond. Furthermore, this formula also represents enantiomers.

[0130] Here, examples of monomers represented by formula (AL-3)-22 include those described in Japanese Patent Publication No. 2000-327633. Specifically, these include, but are not limited to, the following. Note that in the following formula, R A This is the same as described above. [ka]

[0131] Examples of monomers that give repeating units containing an acid-unstable group represented by formula (AL-3) include (meth)acrylic acid esters containing a franziyl group, a tetrahydrofranziyl group, or an oxanorbornanediyl group, represented by the following formula (AL-3)-23. [ka]

[0132] In formula (AL-3)-23, R A The same as above. R Lc12 and R Lc13 These are, independently, hydrocarbyl groups having 1 to 10 carbon atoms. Lc12 and R Lc13 These atoms may bond with each other to form an alicyclic ring with the carbon atoms to which they are bonded. Lc14 This is a franziyl group, a tetrahydrofranziyl group, or an oxanorbornanediyl group. Lc15 This is a C1-C10 hydrocarbyl group which may contain hydrogen atoms or heteroatoms. The hydrocarbyl group may be linear, branched, or cyclic. Specific examples include a saturated C1-C10 hydrocarbyl group.

[0133] The monomers represented by formula (AL-3)-23 include, but are not limited to, those listed below. Note that in the following formula, R A The same applies as above, where Ac is an acetyl group and Me is a methyl group. [ka]

[0134] [ka]

[0135] In addition to the aforementioned acid-unstable groups, acid-unstable groups containing aromatic groups as described in Japanese Patent Publication No. 5565293, Japanese Patent Publication No. 5434983, Japanese Patent Publication No. 5407941, Japanese Patent Publication No. 5655756, and Japanese Patent Publication No. 5655755 may also be used.

[0136] The base polymer may further contain repeating units c comprising a hydroxyl group, a carboxyl group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonic acid ester bond, a cyano group, an amide bond, and an adhesive group selected from -OC(=O)-S- and -OC(=O)-NH-.

[0137] Examples of monomers that give repeating units c are listed below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0138] [ka]

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] [ka]

[0148] [ka]

[0149] The base polymer may further contain at least one selected from the repeating units represented by the following formula (d1) (hereinafter also referred to as repeating unit d1), the repeating unit represented by the following formula (d2) (hereinafter also referred to as repeating unit d2), and the repeating unit represented by the following formula (d3) (hereinafter also referred to as repeating unit d3). [ka]

[0150] In equations (d1) to (d3), R A Each of these is independently either a hydrogen atom or a methyl group. 1 This refers to a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, or -OZ 11 -, -C(=O)-OZ 11 -or -C(=O)-NH-Z 11 - is Z 11This is an aliphatic hydrocarbylene group, phenylene group, naphthylene group having 1 to 6 carbon atoms, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 These are single bonds or ester bonds. 3 This is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -OC(=O)- Z 31 This is an aliphatic hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, a bromine atom, or an iodine atom. 4 This is a methylene group, a 2,2,2-trifluoro-1,1-ethanediyl group, or a carbonyl group. 5 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, phenylene groups substituted with trifluoromethyl groups, -OZ 51 -, -C(=O)-OZ 51 -or -C(=O)-NH-Z 51 - is Z 51 This is a phenylene group substituted with an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, a halogen atom, or a hydroxyl group. 1 , Z 11 , Z 31 and Z 51 The aliphatic hydrocarbylene group represented by may be saturated or unsaturated, and may be linear, branched, or cyclic.

[0151] In equations (d1) to (d3), R 21 ~R 28Each of these is a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a halogen atom or a heteroatom. Examples of the halogen atom include fluorine, chlorine, bromine, and iodine atoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formulas (1-1) and (1-2) described later. 101 ~R 105 Examples similar to those given in the explanation can be cited.

[0152] Also, R 23 and R 24 or R 26 and R 27 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. In this case, the ring is defined as R in the explanation of formula (1-1) described later. 101 and R 102 Examples of rings that can be formed when these elements combine with the sulfur atom to which they are bonded are similar to those exemplified.

[0153] In formula (d1), M - This is a non-nucleophilic counterion. Examples of the aforementioned non-nucleophilic counterions include halide ions such as chloride ions and bromide ions, fluoroalkyl sulfonate ions such as triflate ions, 1,1,1-trifluoroethanesulfonate ions and nonafluorobutanesulfonate ions, aryl sulfonate ions such as tosylate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions and 1,2,3,4,5-pentafluorobenzenesulfonate ions, alkyl sulfonate ions such as mesylate ions and butanesulfonate ions, imide ions such as bis(trifluoromethylsulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions and bis(perfluorobutylsulfonyl)imide ions, and methide ions such as tris(trifluoromethylsulfonyl)methide ions and tris(perfluoroethylsulfonyl)methide ions.

[0154] Examples of the aforementioned non-nucleophilic counterions include a sulfonate ion in which the α-position is substituted with a fluorine atom, represented by the following formula (d1-1), and a sulfonate ion in which the α-position is substituted with a fluorine atom and the β-position is substituted with a trifluoromethyl group, represented by the following formula (d1-2). [ka]

[0155] In formula (d1-1), R 31 R is a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and the hydrocarbyl group may contain an ether bond, an ester bond, a carbonyl group, a lactone ring, or a fluorine atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (1A') described later. 111 Examples of hydrocarbyl groups represented by the symbol shown are similar to those exemplified.

[0156] In formula (d1-2), R 32 R is a hydrogen atom, a hydrocarbyl group having 1 to 30 carbon atoms, or a hydrocarbylcarbonyl group having 2 to 30 carbon atoms, and the hydrocarbyl group and hydrocarbylcarbonyl group may contain an ether bond, an ester bond, a carbonyl group, or a lactone ring. The hydrocarbyl portion of the hydrocarbyl group and hydrocarbylcarbonyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (1A') described later. 111 Examples of hydrocarbyl groups represented by the symbol shown are similar to those exemplified.

[0157] Examples of monomer cations that give the repeating unit d1 are listed below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0158] Specific examples of monomer cations that give repeating units d2 or d3 include those similar to those exemplified as cations of sulfonium salts represented by formula (1-1) described later.

[0159] Examples of monomer anions that give the repeating unit d2 are listed below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0160] [ka]

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] [ka]

[0167] [ka]

[0168] [ka]

[0169] [ka]

[0170] Examples of monomer anions that give the repeating unit d3 are listed below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0171] [ka]

[0172] The repeating units d1 to d3 function as acid generators. By binding the acid generators to the polymer backbone, acid diffusion is reduced, preventing a decrease in resolution due to blurring caused by acid diffusion. Furthermore, the uniform dispersion of the acid generators improves edge roughness and CDU. When using a base polymer containing repeating units d1 to d3 (i.e., a polymer-bound type acid generator), the addition of the additive-type acid generator described later can be omitted.

[0173] The base polymer may contain repeating units e containing iodine atoms. Examples of monomers that give repeating units e are, but are not limited to, those listed below. In the following formula, R A This is the same as described above. [ka]

[0174] [ka]

[0175] [ka]

[0176] The base polymer may contain repeating units f other than those described above. Examples of repeating units f include those derived from styrene, vinylnaphthalene, indene, acenaphthylene, coumarin, coumarone, and the like.

[0177] In the base polymer, the content ratios of repeating units b1, b2, c, d1, d2, d3, e, and f are preferably 0≦b1≦0.9, 0≦b2≦0.9, 0.1≦b1+b2≦0.9, 0≦c≦0.9, 0≦d1≦0.5, 0≦d2≦0.5, 0≦d3≦0.5, 0≦d1+d2+d3≦0.5, 0≦e≦0.5, and 0≦f≦0.5, with 0≦b1≦0.8, 0≦b2≦0.8, and 0.2≦b1+b2≦0. 8, 0≦c≦0.8, 0≦d1≦0.4, 0≦d2≦0.4, 0≦d3≦0.4, 0≦d1+d2+d3≦0.4, 0≦e≦0.4 and 0≦f≦0.4 are more preferred, and 0≦b1≦0.7, 0≦b2≦0.7, 0.25≦b1+b2≦0.7, 0≦c≦0.7, 0≦d1≦0.3, 0≦d2≦0.3, 0≦d3≦0.3, 0≦d1+d2+d3≦0.3, 0≦e≦0.3 and 0≦f≦0.3 are even more preferred, where b1+b2+c+d1+d2+d3+e+f=1.0.

[0178] To synthesize the base polymer, for example, a monomer that provides the repeating units described above may be polymerized by heating it in an organic solvent with a radical polymerization initiator and a chain transfer agent of an ammonium salt linked to a thiol group. By using the chain transfer agent, the ends of the base polymer can be sealed with an ammonium salt linked to a sulfide group. The polymerization initiator and chain transfer agent may be added at the start of polymerization, during polymerization, or gradually during polymerization. Alternatively, the polymerization reaction may be carried out using an amine compound linked to a thiol group, and the ends may be converted to ammonium salts by a neutralization reaction between the synthesized polymer having amino groups at its ends and an acid containing a fluorine atom.

[0179] Chain transfer agents are generally used to lower the molecular weight of polymers. Polymerization is carried out by radicals generated from polymerization initiators, but activated radicals move to the ammonium salt linked to the thiol group in this invention, and polymerization starts from there. In this way, the ammonium salt linked to the thiol group is bonded to the ends of the polymer.

[0180] A lower molecular weight has the advantage of reducing swelling in the developer solution. However, a disadvantage is that the lower glass transition temperature (Tg) of the polymer leads to increased acid diffusion in the PEB. Polymer-type quenchers are highly effective at suppressing acid diffusion, and this effect can be maintained even when the polymer molecular weight is low. In particular, by placing the quencher at the polymer end, as in the present invention, the acid capture ability can be enhanced. The aim of the present invention is to provide a material that can achieve both reduced swelling in the developer solution due to low molecular weight and low acid diffusion.

[0181] The amount of the chain transfer agent used can be selected according to the target molecular weight, the monomer used as raw material, and manufacturing conditions such as polymerization temperature and polymerization method.

[0182] A commercially available radical polymerization initiator can be used as the polymerization initiator. Preferably, it is a radical polymerization initiator such as an azo initiator or a peroxide initiator. The polymerization initiator can be used alone or in combination. The amount of polymerization initiator used can be selected according to the target molecular weight, the monomer used as the raw material, and the manufacturing conditions such as the polymerization temperature and polymerization method. Specific examples of polymerization initiators are given below.

[0183] Specific examples of azo initiators include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylpropionic acid)dimethyl, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(cyclohexane-1-carbonnitrile), 4,4'-azobis(4-cyanovaleric acid), and 2,2'-azobis(isobutyric acid)dimethyl. Specific examples of peroxide initiators include benzoyl peroxide, decanoyl peroxide, lauroyl peroxide, succinate peroxide, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxypivaloate, and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate.

[0184] Examples of organic solvents used during polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and dioxane. The polymerization temperature is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0185] When copolymerizing monomers containing hydroxyl groups, the hydroxyl groups may be substituted with acetal groups that are easily deprotected by acids such as ethoxyethoxy groups during polymerization, and then deprotected with a weak acid and water after polymerization. Alternatively, they may be substituted with acetyl groups, formyl groups, pivaloyl groups, etc., and then subjected to alkaline hydrolysis after polymerization.

[0186] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, acetoxystyrene or acetoxyvinylnaphthalene may be used instead of hydroxystyrene or hydroxyvinylnaphthalene, and the acetoxy group may be deprotected by alkaline hydrolysis after polymerization to obtain hydroxystyrene or hydroxyvinylnaphthalene.

[0187] Ammonia water, triethylamine, etc., can be used as the base during alkaline hydrolysis. The reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0188] The base polymer has a polystyrene-based weight-average molecular weight (Mw) of 1,000 to 500,000, more preferably 2,000 to 30,000, determined by gel permeation chromatography (GPC) using THF as a solvent. If Mw is too low, the resist material will have poor heat resistance, and if it is too high, its alkali solubility will decrease, making it more likely for the trailing phenomenon to occur after pattern formation.

[0189] Furthermore, if the molecular weight distribution (Mw / Mn) of the base polymer is broad, the presence of low-molecular-weight and high-molecular-weight polymers may cause foreign matter to be observed on the pattern or deterioration of the pattern shape after exposure. As the pattern rule becomes finer, the influence of Mw and Mw / Mn tends to increase. Therefore, in order to obtain a resist material suitable for fine pattern dimensions, it is preferable that the Mw / Mn of the base polymer be narrowly dispersed, between 1.0 and 2.0, and particularly between 1.0 and 1.5.

[0190] The base polymer may contain two or more polymers with different composition ratios, Mw, and Mw / Mn. Alternatively, polymers containing different terminal structures a may be blended together, or a polymer containing terminal structure a may be blended with a polymer not containing terminal structure a.

[0191] [Acid Generator] The positive resist material of the present invention may contain an acid generator that generates a strong acid (hereinafter also referred to as an additive-type acid generator). Here, a strong acid means a compound that has sufficient acidity to cause a deprotection reaction of acid-unstable groups of the base polymer.

[0192] Examples of the acid-generating agent include compounds that generate acid in response to active light or radiation (photoacid generators). Any compound that generates acid upon irradiation with high-energy rays can be used as the photoacid generator, but those that generate sulfonic acid, imido acid, or methidoic acid are preferred. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, etc. Specific examples of photoacid generators are those described in paragraphs

[0122] to

[0142] of Japanese Patent Publication No. 2008-111103.

[0193] Furthermore, sulfonium salts represented by the following formula (1-1) and iodonium salts represented by the following formula (1-2) can also be suitably used as photoacid generators. [ka]

[0194] In equations (1-1) and (1-2), R 101 ~R 105 Each of these is independently a C1-C20 hydrocarbyl group which may contain a halogen atom or a heteroatom.

[0195] Examples of the halogen atoms mentioned above include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0196] R 101 ~R 105The hydrocarbyl group, represented by , having 1 to 20 carbon atoms, may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C20 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl; C3-C20 cyclic saturated hydrocarbyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; C2-C20 alkenyl groups such as vinyl, propenyl, butenyl, and hexenyl; and ethynyl groups. Examples include alkynyl groups with 2 to 20 carbon atoms, such as propynyl and butynyl groups; cyclic unsaturated aliphatic hydrocarbyl groups with 3 to 20 carbon atoms, such as cyclohexenyl and norbornenyl groups; aryl groups with 6 to 20 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, and tert-butylnaphthyl groups; aralkyl groups with 7 to 20 carbon atoms, such as benzyl and phenethyl groups; and groups obtained by combining these.

[0197] Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- groups of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms, and as a result, the material may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc.

[0198] Also, R 101 and R 102 These may bond with each other to form a ring with the sulfur atom to which they are bonded. In this case, the ring is preferably structured as shown below. [ka] (In the formula, the dashed line represents R 103 (This is a combination of the two.)

[0199] Examples of cations of the sulfonium salt represented by formula (1-1) include, but are not limited to, those listed below. [ka]

[0200] [ka]

[0201] [ka]

[0202] [ka]

[0203] [ka]

[0204]

change

[0205]

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[0206]

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[0207]

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[0208]

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[0209]

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[0210]

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[0211]

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[0212]

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[0213]

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[0214] [ka]

[0215] [ka]

[0216] [ka]

[0217] [ka]

[0218] [ka]

[0219] [ka]

[0220] [ka]

[0221] [ka]

[0222] The cations of the iodonium salt represented by formula (1-2) include, but are not limited to, those listed below. [ka]

[0223] [ka]

[0224] In equations (1-1) and (1-2), Xa - This is an anion selected from the following formulas (1A) to (1D). [ka]

[0225] In formula (1A), R fa R is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (1A') described later. 111 Examples of hydrocarbyl groups represented by the symbol shown are similar to those exemplified.

[0226] The anion represented by formula (1A) is preferably the one represented by formula (1A') below. [ka]

[0227] In formula (1A'), R HF R is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 111 This is a hydrocarbyl group having 1 to 38 carbon atoms, which may contain heteroatoms. The heteroatoms are preferably oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms, etc., with oxygen atoms being more preferred. From the viewpoint of obtaining high resolution in fine pattern formation, the hydrocarbyl group having 6 to 30 carbon atoms is particularly preferred.

[0228] R 111The hydrocarbyl group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include C1-C38 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, and eicosyl; cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, Examples include cyclic saturated hydrocarbyl groups with 3 to 38 carbon atoms, such as norbornylmethyl group, tricyclodecanyl group, tetracyclododecanyl group, tetracyclododecanylmethyl group, and dicyclohexylmethyl group; unsaturated aliphatic hydrocarbyl groups with 2 to 38 carbon atoms, such as allyl group and 3-cyclohexenyl group; aryl groups with 6 to 38 carbon atoms, such as phenyl group, 1-naphthyl group, and 2-naphthyl group; aralkyl groups with 7 to 38 carbon atoms, such as benzyl group and diphenylmethyl group; and groups obtained by combining these.

[0229] Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, nitrogen atom, or halogen atom, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, or nitrogen atom, and as a result, it may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, etc. Examples of hydrocarbyl groups containing heteroatoms include a tetrahydrofuryl group, a methoxymethyl group, an ethoxymethyl group, a methylthiomethyl group, an acetamidomethyl group, a trifluoroethyl group, a (2-methoxyethoxy)methyl group, an acetoxymethyl group, a 2-carboxy-1-cyclohexyl group, a 2-oxopropyl group, a 4-oxo-1-adamantyl group, a 3-oxocyclohexyl group, etc.

[0230] For details on the synthesis of sulfonium salts containing the anion represented by formula (1A'), please refer to Japanese Patent Publication No. 2007-145797, Japanese Patent Publication No. 2008-106045, Japanese Patent Publication No. 2009-7327, Japanese Patent Publication No. 2009-258695, etc. Also, sulfonium salts described in Japanese Patent Publication No. 2010-215608, Japanese Patent Publication No. 2012-41320, Japanese Patent Publication No. 2012-106986, Japanese Patent Publication No. 2012-153644, etc., can be suitably used.

[0231] Examples of anions represented by formula (1A) include those similar to those exemplified as anions represented by formula (1A) in Japanese Patent Publication No. 2018-197853.

[0232] In formula (1B), R fb1 and R fb2 Each of these is a hydrocarbyl group having 1 to 40 carbon atoms, which may each contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (1A'). 111 Examples of hydrocarbyl groups represented by R include those similar to those exemplified. fb1 and R fb2 Preferably, R is a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 and R fb2 This refers to the groups that bond to each other (-CF2-SO2-N - It may form a ring with -SO2-CF2-), in which case R fb1 and R fb2 The group obtained by the bonding of these two elements is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0233] In formula (1C), R fc1 , R fc2 and R fc3 Each of these is a hydrocarbyl group having 1 to 40 carbon atoms, which may each contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (1A').111 Examples of hydrocarbyl groups represented by R include those similar to those exemplified. fc1 , R fc2 and R fc3 Preferably, R is a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 and R fc2 This refers to the groups that bond to each other (-CF2-SO2-C - It may form a ring with -SO2-CF2-), in which case R fc1 and R fc2 The group obtained by the bonding of these two elements is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0234] In formula (1D), R fd R is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain heteroatoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (1A'). 111 Examples of hydrocarbyl groups represented by the same formula as those exemplified above include those shown.

[0235] The synthesis of sulfonium salts containing the anion represented by formula (1D) is described in detail in Japanese Patent Publication No. 2010-215608 and Japanese Patent Publication No. 2014-133723.

[0236] Examples of anions represented by formula (1D) include those similar to those exemplified as anions represented by formula (1D) in Japanese Patent Publication No. 2018-197853.

[0237] Furthermore, the photoacid generator containing the anion represented by formula (1D) does not have a fluorine atom at the α-position of the sulfo group, but has two trifluoromethyl groups at the β-position, which gives it sufficient acidity to cleave acid-unstable groups in the base polymer. Therefore, it can be used as a photoacid generator.

[0238] As a photoacid generator, one represented by the following formula (2) can also be suitably used. [ka]

[0239] In formula (2), R 201 and R 202 Each of these is independently a hydrocarbyl group having 1 to 30 carbon atoms, which may contain a halogen atom or a heteroatom. 203 This is a hydrocarbylene group having 1 to 30 carbon atoms, which may contain heteroatoms. Also, R 201 , R 202 and R 203 Any two of these may bond with each other to form a ring with the sulfur atom to which they are bonded. In this case, the ring is defined as R in the explanation of formula (1-1). 101 and R 102 Examples of rings that can be formed when these elements combine with the sulfur atom to which they are bonded are similar to those exemplified.

[0240] R 201 and R 202 The hydrocarbyl group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0 2,6Examples include cyclic saturated hydrocarbyl groups having 3 to 30 carbon atoms, such as decanyl and adamantyl groups; aryl groups having 6 to 30 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, and anthracenyl groups; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- groups of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms, and as a result, the material may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc.

[0241] R 203The hydrocarbylene group represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkane diyl groups with 1 to 30 carbon atoms, such as methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group, etc.; cyclopentanediyl group, cyclohex Examples include cyclic saturated hydrocarbylene groups having 3 to 30 carbon atoms, such as xanediyl, norbornanediyl, and adamantanediyl groups; arylene groups having 6 to 30 carbon atoms, such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, and tert-butylnaphthylene; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, nitrogen atom, or halogen atom, and some of the -CH2- groups of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, or nitrogen atom, resulting in the inclusion of a hydroxyl group, fluorine atom, chlorine atom, bromine atom, iodine atom, cyano group, nitro group, carbonyl group, ether bond, ester bond, sulfonic acid ester bond, carbonate bond, lactone ring, sultone ring, carboxylic acid anhydride, haloalkyl group, etc. The heteroatom is preferably an oxygen atom.

[0242] In formula (2), L CThis is a 1-20 carbon atom hydrocarbylene group which may contain single bonds, ether bonds, or heteroatoms. The hydrocarbylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R 203 Examples of hydrocarbylene groups represented by the same formula as those exemplified above include the same groups as those shown.

[0243] In formula (2), X A , X B , X C and X D Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. However, X A , X B , X C and X D At least one of these is a fluorine atom or a trifluoromethyl group.

[0244] In equation (2), t is an integer between 0 and 3.

[0245] The photoacid generator represented by formula (2) is preferably the one represented by formula (2') below. [ka]

[0246] In formula (2'), L C The same as above. R HF R is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 301 , R 302 and R 303 Each of these is independently a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a hydrogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (1A'). 111 Examples of hydrocarbyl groups represented by the formula shown are similar to those exemplified. x and y are each independent integers from 0 to 5, and z is an integer from 0 to 4.

[0247] Examples of photoacid generators represented by formula (2) include those similar to those exemplified as photoacid generators represented by formula (2) in Japanese Patent Publication No. 2017-026980.

[0248] Among the photoacid generators, those containing an anion represented by formula (1A') or (1D) are particularly preferred because they exhibit low acid diffusion and excellent solubility in solvents. Furthermore, those represented by formula (2') are particularly preferred because they exhibit extremely low acid diffusion.

[0249] As the photoacid generator, a sulfonium salt or iodonium salt containing an anion having an aromatic ring substituted with an iodine or bromine atom can also be used. Examples of such salts are those represented by the following formulas (3-1) or (3-2). [ka]

[0250] In equations (3-1) and (3-2), p is an integer satisfying 1 ≤ p ≤ 3. q and r are integers satisfying 1 ≤ q ≤ 5, 0 ≤ r ≤ 3, and 1 ≤ q + r ≤ 5. q is preferably an integer satisfying 1 ≤ q ≤ 3, and more preferably 2 or 3. r is preferably an integer satisfying 0 ≤ r ≤ 2.

[0251] In equations (3-1) and (3-2), X BI These atoms are iodine atoms or bromine atoms, and when p and / or q are 2 or greater, they may be the same or different from each other.

[0252] In equations (3-1) and (3-2), L 1 This is a saturated hydrocarbylene group having 1 to 6 carbon atoms, which may contain a single bond, an ether bond, or an ester bond, or an ether bond or an ester bond. The saturated hydrocarbylene group may be linear, branched, or cyclic.

[0253] In equations (3-1) and (3-2), L 2When p is 1, it is a single bond or a divalent linking group having 1 to 20 carbon atoms, and when p is 2 or 3, it is a (p+1) valent linking group having 1 to 20 carbon atoms, and the linking group may contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0254] In equations (3-1) and (3-2), R 401 This may include a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, or an amino group, or a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amino group, or an ether bond, and may contain a C1-C20 hydrocarbyl group, a C1-C20 hydrocarbyloxy group, a C2-C20 hydrocarbylcarbonyl group, a C2-C20 hydrocarbyloxycarbonyl group, a C2-C20 hydrocarbylcarbonyloxy group, or a C1-C20 hydrocarbylsulfonyloxy group, or -N(R 401A )(R 401B ), -N(R 401C )-C(=O)-R 401D Or -N(R 401C )-C(=O)-OR 401D That is. R 401A and R 401B Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 401C R is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. 401DThis is an aliphatic hydrocarbyl group having 1 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. The aliphatic hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. The hydrocarbyl group, hydrocarbyloxy group, hydrocarbylcarbonyl group, hydrocarbyloxycarbonyl group, hydrocarbylcarbonyloxy group, and hydrocarbylsulfonyloxy group may be linear, branched, or cyclic. When p and / or r is 2 or more, each R 401 They may be the same or different from one another.

[0255] Of these, R 401 Examples include hydroxyl groups, -N(R 401C )-C(=O)-R 401D , -N(R 401C )-C(=O)-OR 401D Fluorine atoms, chlorine atoms, bromine atoms, methyl groups, methoxy groups, etc. are preferred.

[0256] In equations (3-1) and (3-2), Rf 1 ~Rf 4 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of these is either a fluorine atom or a trifluoromethyl group. Also, Rf 1 and Rf 2 These may combine to form a carbonyl group. In particular, Rf 3 and Rf 4 It is preferable that both are fluorine atoms.

[0257] In equations (3-1) and (3-2), R 402 ~R 406Each of these is a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a halogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. For example, in the explanation of formulas (1-1) and (1-2), R 101 ~R 105 Examples of hydrocarbyl groups represented by the above are similar to those exemplified. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a hydroxyl group, carboxyl group, halogen atom, cyano group, nitro group, mercapto group, sultone ring, sulfo group, or sulfonium salt-containing group, and some of the -CH2- of the hydrocarbyl group may be substituted with an ether bond, ester bond, carbonyl group, amide bond, carbonate bond, or sulfonic acid ester bond. 402 and R 403 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. In this case, the ring is R as described in the explanation of formula (1-1). 101 and R 102 Examples of rings that can be formed when these elements combine with the sulfur atom to which they are bonded are similar to those exemplified.

[0258] Examples of cations for the sulfonium salt represented by formula (3-1) are the same as those exemplified for the sulfonium salt represented by formula (1-1). Similarly, examples of cations for the iodonium salt represented by formula (3-2) are the same as those exemplified for the iodonium salt represented by formula (1-2).

[0259] The anions of the onium salt represented by formula (3-1) or (3-2) include, but are not limited to, those listed below. Note that in the following formulas, X BI This is the same as described above. [ka]

[0260] [ka]

[0261]

change

[0262]

change

[0263]

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[0264]

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[0265]

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[0266]

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[0267]

change

[0268]

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[0269]

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[0270]

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[0271]

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[0272]

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[0273]

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[0274]

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[0275]

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[0276]

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[0277]

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[0278]

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[0279]

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[0280]

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[0281]

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[0282] When the positive-type resist material of the present invention contains an additive-type acid generator, its content is preferably 0.1 to 50 parts by mass, and more preferably 1 to 40 parts by mass, per 100 parts by mass of the base polymer. The additive-type acid generator may be used alone or in combination of two or more types. By the base polymer containing repeating units d1 to d3 and / or the additive-type acid generator, the positive-type resist material of the present invention can function as a chemically amplified positive-type resist material.

[0283] [Organic solvents] The positive resist material of the present invention may contain an organic solvent. The organic solvent is not particularly limited as long as it can dissolve the components described above and the components described later. Examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone, as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, and pro Examples include ethers such as pyrene glycol dimethyl ether and diethylene glycol dimethyl ether; esters such as ethyl lactate (L-form), ethyl lactate (D-form), ethyl lactate (DL-form), ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; and lactones such as γ-butyrolactone.

[0284] In the positive-type resist material of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass, and more preferably 200 to 8,000 parts by mass, per 100 parts by mass of the base polymer. The organic solvent may be used alone or as a mixture of two or more types.

[0285] [Quencher] The positive-type resist material of the present invention has an ammonium salt type quencher at the polymer terminal, but may also contain a separate quencher. A quencher is a compound that can prevent the diffusion of acid generated from the acid generator in the resist material to the unexposed areas by trapping the acid.

[0286] Examples of the quencher include conventional basic compounds. Examples of conventional basic compounds include primary, secondary, and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, carbamates, etc. Particularly preferred are primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Publication No. 2008-111103, especially amine compounds having a hydroxyl group, ether bond, ester bond, lactone ring, cyano group, or sulfonic acid ester bond, or compounds having a carbamate group described in Japanese Patent Publication No. 3790649. By adding such basic compounds, for example, the diffusion rate of acid in the resist film can be further suppressed or its shape corrected.

[0287] Furthermore, examples of the quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids, carboxylic acids, or fluorinated alkoxides whose α-position is not fluorinated, as described in Japanese Patent Publication No. 2008-158339. Sulfonic acids, imido acids, or methidic acids with α-position fluorinated are necessary to deprotect the acid-unstable group of the carboxylic acid ester, but salt exchange with an onium salt with α-position not fluorinated releases sulfonic acids, carboxylic acids, or fluorinated alcohols with α-position not fluorinated. Since sulfonic acids, carboxylic acids, and fluorinated alcohols with α-position not fluorinated do not undergo deprotection reactions, they function as quenchers.

[0288] Examples of such quenchers include compounds represented by formula (4) below (onium salts of sulfonic acids with the α-position not fluorinated), compounds represented by formula (5) below (onium salts of carboxylic acids), and compounds represented by formula (6) below (onium salts of alkoxides). [ka]

[0289] In formula (4), R 501 This refers to a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a hydrogen atom or a heteroatom, but excludes those in which the hydrogen atom bonded to the α-carbon atom of the sulfo group is substituted with a fluorine atom or a fluoroalkyl group.

[0290] The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 40 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl groups; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0 2,6 ] Cyclic saturated hydrocarbyl groups with 3 to 40 carbon atoms, such as decanyl group, adamantyl group, and adamantylmethyl group; alkenyl groups with 2 to 40 carbon atoms, such as vinyl group, allyl group, propenyl group, butenyl group, and hexenyl group; cyclic unsaturated aliphatic hydrocarbyl groups with 3 to 40 carbon atoms, such as cyclohexenyl group; phenyl group, naphthyl group, alkylphenyl group (2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-methylmethylphenyl group, 4-methylphenyl group, methylphenyl group, methylphenyl group, 4-methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, methylphenyl group, Examples include aryl groups with 6 to 40 carbon atoms, such as t-butylphenyl group, 4-n-butylphenyl group, dialkylphenyl group (2,4-dimethylphenyl group, 2,4,6-triisopropylphenyl group, etc.), alkylnaphthyl group (methylnaphthyl group, ethylnaphthyl group, etc.), and dialkylnaphthyl group (dimethylnaphthyl group, diethylnaphthyl group, etc.); and aralkyl groups with 7 to 40 carbon atoms, such as benzyl group, 1-phenylethyl group, and 2-phenylethyl group.

[0291] Furthermore, some of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, nitrogen atom, or halogen atom, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, or nitrogen atom, and as a result, it may contain a hydroxyl group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, etc. Examples of hydrocarbyl groups containing heteroatoms include heteroaryl groups such as thienyl and indolyl groups; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl groups; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl groups; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl groups; and aryloxoalkyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl groups.

[0292] In formula (5), R 502 R is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain heteroatoms. 502 The hydrocarbyl group represented by R is 501 Examples of hydrocarbyl groups represented by the same formulas as those exemplified above include the following. Other specific examples include fluorine-containing alkyl groups such as trifluoromethyl group, trifluoroethyl group, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl group, and 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl group; and fluorine-containing aryl groups such as pentafluorophenyl group and 4-trifluoromethylphenyl group.

[0293] In formula (6), R 503This is a saturated hydrocarbyl group having 1 to 8 carbon atoms and having at least 3 fluorine atoms, or an aryl group having 6 to 10 carbon atoms and having at least 3 fluorine atoms, and may also have a nitro group.

[0294] In formulas (4) to (6), Mq + This is an onium cation. The onium cation is preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and more preferably a sulfonium cation or an iodonium cation. The sulfonium cation is the same as that exemplified as the cation of the sulfonium salt represented by formula (1-1). The iodonium cation is the same as that exemplified as the cation of the iodonium salt represented by formula (1-2).

[0295] As a quencher, a sulfonium salt of an iodized benzene ring-containing carboxylic acid represented by the following formula (7) can also be suitably used. [ka]

[0296] In formula (7), R 601 This may be a saturated hydrocarbyl group having 1 to 6 carbon atoms, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms, or a saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms, or -N(R 601A )-C(=O)-R 601B Or -N(R 601A )-C(=O)-OR 601B That is. R 601A R is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 601B This is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms.

[0297] In equation (7), x' is an integer between 1 and 5. y' is an integer between 0 and 3. z' is an integer between 1 and 3. L 11 This is a single bond or a (z'+1) valence linking group having 1 to 20 carbon atoms, and may contain at least one selected from an ether bond, carbonyl group, ester bond, amide bond, sultone ring, lactam ring, carbonate bond, halogen atom, hydroxyl group, and carboxyl group. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group, and saturated hydrocarbylsulfonyloxy group may be linear, branched, or cyclic. When y' and / or z' is 2 or more, each R 601 They may be the same or different from one another.

[0298] In formula (7), R 602 , R 603 and R 604 Each of these is a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a halogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formulas (1-1) and (1-2). 101 ~R 105 Examples of hydrocarbyl groups represented by the above are similar to those exemplified. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a hydroxyl group, carboxyl group, halogen atom, oxo group, cyano group, nitro group, sultone ring, sulfo group, or sulfonium salt-containing group, and some of the -CH2- of the hydrocarbyl group may be substituted with an ether bond, ester bond, carbonyl group, amide bond, carbonate bond, or sulfonic acid ester bond. 602 and R 603 These may bond with each other to form a ring with the sulfur atom to which they are bonded.

[0299] A specific example of the compound represented by formula (7) is the one described in Japanese Patent Publication No. 2017-219836.

[0300] Another example of the aforementioned quencher is the polymer-type quencher described in Japanese Patent Publication No. 2008-239918. This enhances the rectangularity of the resist pattern by oriented on the surface of the resist film. The polymer-type quencher also has the effect of preventing film thinning of the pattern and rounding of the pattern top when a protective film for immersion lithography is applied.

[0301] When the positive resist material of the present invention contains the quencher, its content is preferably 0 to 5 parts by mass, and more preferably 0 to 4 parts by mass, per 100 parts by mass of the base polymer. The quencher may be used alone or in combination of two or more types.

[0302] [Other ingredients] In addition to the components described above, the positive resist material of the present invention may also contain surfactants, dissolution inhibitors, water-repellent enhancers, acetylene alcohols, and the like.

[0303] Examples of the surfactants mentioned above include those described in paragraphs

[0165] to

[0166] of Japanese Patent Publication No. 2008-111103. By adding a surfactant, the coatability of the resist material can be further improved or controlled. When the positive-type resist material of the present invention contains the surfactant, its content is preferably 0.0001 to 10 parts by mass per 100 parts by mass of the base polymer. The surfactant may be used alone or in combination of two or more types.

[0304] By incorporating a dissolution inhibitor into the positive resist material of the present invention, the difference in dissolution rate between the exposed and unexposed areas can be further increased, thereby further improving the resolution. Examples of the dissolution inhibitor include compounds having a molecular weight of preferably 100 to 1,000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups in the molecule, in which the hydrogen atoms of the phenolic hydroxyl groups are substituted with acid-unstable groups in a proportion of 0 to 100 mol% overall, or compounds containing a carboxyl group in the molecule, in which the hydrogen atoms of the carboxyl group are substituted with acid-unstable groups in an average proportion of 50 to 100 mol overall. Specifically, examples include compounds in which the hydrogen atoms of the hydroxyl group or carboxyl group of bisphenol A, trisphenol, phenolphthalein, cresol novolac, naphthalenecarboxylic acid, adamantanecarboxylic acid, and cholic acid are substituted with acid-unstable groups, as described, for example, in paragraphs

[0155] to

[0178] of Japanese Patent Application Publication No. 2008-122932.

[0305] When the positive resist material of the present invention contains the dissolution inhibitor, its content is preferably 0 to 50 parts by mass, and more preferably 5 to 40 parts by mass, per 100 parts by mass of the base polymer. The dissolution inhibitor may be used alone or in combination of two or more types.

[0306] The water-repellent enhancer improves the water repellency of the resist film surface and can be used in immersion lithography without a topcoat. Preferred water-repellent enhancers include polymers containing alkyl fluoride, polymers containing 1,1,1,3,3,3-hexafluoro-2-propanol residues of a specific structure, and those exemplified in Japanese Patent Publication No. 2007-297590 and Japanese Patent Publication No. 2008-111103 are more preferred. The water-repellent enhancer needs to be soluble in an alkaline developer or an organic solvent developer. The aforementioned water-repellent enhancer having a specific 1,1,1,3,3,3-hexafluoro-2-propanol residue exhibits good solubility in the developer. As a water-repellent enhancer, polymers containing repeating units including amino groups or amine salts are highly effective in preventing acid evaporation in the PEB and thus preventing poor hole pattern opening after development. When the positive resist material of the present invention contains a water-repellency enhancer, its content is preferably 0 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the base polymer. The water-repellency enhancer may be used alone or in combination of two or more types.

[0307] Examples of the acetylene alcohols mentioned above include those described in paragraphs

[0179] to

[0182] of Japanese Patent Publication No. 2008-122932. When the positive-type resist material of the present invention contains acetylene alcohols, the content is preferably 0 to 5 parts by mass per 100 parts by mass of the base polymer. The acetylene alcohols may be used individually or in combination of two or more types.

[0308] [Pattern formation method] When the positive-type resist material 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 may include a step of forming a resist film on a substrate using the positive-type resist material described above, a step of exposing the resist film with high-energy rays, and a step of developing the exposed resist film using a developer.

[0309] First, the positive resist material of the present invention is applied to a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective coating, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.) by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor coating, so that the coating thickness is 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.

[0310] Next, the resist film is exposed using high-energy rays. Examples of high-energy rays include ultraviolet rays, far-ultraviolet rays, EB rays, EUV rays with wavelengths of 3 to 15 nm, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation. When using ultraviolet rays, far-ultraviolet rays, EUV rays, X-rays, soft X-rays, excimer laser light, gamma rays, or synchrotron radiation as the high-energy rays, the exposure amount is preferably 1 to 200 mJ / cm², either directly or using a mask to form the desired pattern. 2 To the extent, more preferably 10 to 100 mJ / cm² 2 Irradiate to the extent of the above. When using EB as the high-energy beam, the exposure dose is preferably 0.1 to 100 μC / cm². 2 To a degree, more preferably 0.5 to 50 μC / cm² 2 The pattern is drawn either directly or using a mask to form the desired pattern. The positive-type resist material of the present invention is particularly suitable for fine patterning using high-energy rays, including KrF excimer laser light, ArF excimer laser light, EB, EUV, i-rays, X-rays, soft X-rays, gamma rays, and synchrotron radiation, and is especially suitable for fine patterning using EB or EUV.

[0311] After exposure, PEB may be performed on a hot plate or in an oven, preferably at 50-150°C for 10 seconds to 30 minutes, more preferably at 60-120°C for 30 seconds to 20 minutes.

[0312] After exposure or PEB, the exposed resist film is developed using a developer solution of an alkaline aqueous solution, preferably 0.1 to 10% by mass, more preferably 2 to 5% by mass, of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), etc., for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, by conventional methods such as the dip method, puddle method, or spray method. The parts that were irradiated with light dissolve in the developer solution, while the parts that were not exposed do not dissolve, and the desired positive pattern is formed on the substrate.

[0313] Using the aforementioned positive-type resist material, negative development can also be performed to obtain a negative-type pattern by organic solvent development. The developers used in this process 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 crotate, ethyl crotate, Examples 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 phenyl acetate, and 2-phenylethyl acetate. These organic solvents may be used individually or in mixtures of two or more.

[0314] At the end of development, rinsing is performed. A solvent that mixes with the developer but does not dissolve the resist film is preferred as the rinsing solution. Preferred solvents include C3-C10 alcohols, C8-C12 ether compounds, C6-C12 alkanes, alkenes, alkynes, and aromatic solvents.

[0315] Specifically, alcohols with 3 to 10 carbon atoms include n-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, and 3-hexanol. Examples include 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 1-octanol, and the like.

[0316] Examples of ether compounds having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert-pentyl ether, and di-n-hexyl ether.

[0317] Examples of alkanes with 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. Examples of alkenes with 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Examples of alkynes with 6 to 12 carbon atoms include hexine, heptine, and octine.

[0318] Examples of aromatic solvents include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[0319] Rinsing can reduce the occurrence of deformation and defects in the resist pattern. However, rinsing is not always necessary, and omitting it can reduce the amount of solvent used.

[0320] The developed hole patterns and trench patterns can also be shrunk using thermal flow, RELACS, or DSA techniques. A shrinking agent is applied to the hole pattern, and crosslinking of the shrinking agent occurs on the surface of the resist film due to the diffusion of an acid catalyst from the resist film during baking, causing the shrinking agent to adhere to the side walls 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, during which excess shrinking agent is removed and the hole pattern is reduced in size. [Examples]

[0321] The present invention will be specifically described below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0322] The chain transfer agents CTA-1 to CTA-27 used in the synthesis of the base polymer are as follows: [ka]

[0323] [ka]

[0324] [ka]

[0325] [1] Synthesis of base polymers The monomers PM-1 to PM-3, AM-1 to AM-10, FM-1, and FM-2 used in the synthesis of the base polymer are as follows. The polymer's Mw is a polystyrene-converted value measured by GPC using THF as the solvent. [ka]

[0326] [ka]

[0327] [ka]

[0328] [Synthesis Example 1] Synthesis of Polymer P-1 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 6.0 g of 4-hydroxystyrene, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 1.1 g of CTA-1 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-1. The composition of polymer P-1 is13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0329] [Synthesis Example 2] Synthesis of Polymer P-2 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 4-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azimobis(isobutyrate)dimethyl and 2.0 g of CTA-2 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-2. The composition of polymer P-2 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0330] [Synthesis Example 3] Synthesis of Polymer P-3 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.0 g of CTA-3 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-3. The composition of polymer P-3 is 13C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0331] [Synthesis Example 4] Synthesis of Polymer P-4 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.8 g of 3-hydroxystyrene, 8.2 g of monomer PM-3, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azimobis(isobutyrate)dimethyl and 2.4 g of CTA-4 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-4. The composition of polymer P-4 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0332] [Synthesis Example 5] Synthesis of Polymer P-5 In a 2 L flask, 11.1 g of monomer AM-1, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.2 g of CTA-5 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-5. The composition of polymer P-5 is 13 C-NMR and 1Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0333] [Synthesis Example 6] Synthesis of Polymer P-6 In a 2 L flask, 8.2 g of monomer AM-2, 4.0 g of monomer AM-3, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 1.4 g of CTA-6 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-6. The composition of polymer P-6 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0334] [Synthesis Example 7] Synthesis of Polymer P-7 In a 2 L flask, 6.7 g of monomer AM-1, 3.8 g of monomer AM-4, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.4 g of CTA-7 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-7. The composition of polymer P-7 is 13 C-NMR and 1Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0335] [Synthesis Example 8] Synthesis of Polymer P-8 In a 2 L flask, 9.0 g of monomer AM-5, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.4 g of CTA-8 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-8. The composition of polymer P-8 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0336] [Synthesis Example 9] Synthesis of Polymer P-9 In a 2 L flask, 10.8 g of monomer AM-6, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.2 g of CTA-9 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-9. The composition of polymer P-9 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0337] [Synthesis Example 10] Synthesis of Polymer P-10 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 3.0 g of 3-hydroxystyrene, 3.2 g of monomer FM-1, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azimobis(isobutyrate)dimethyl and 2.1 g of CTA-10 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-10. The composition of polymer P-10 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0338] [Synthesis Example 11] Synthesis of Polymer P-11 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 3.0 g of 3-hydroxystyrene, 2.7 g of monomer FM-2, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.1 g of CTA-11 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-11. The composition of polymer P-11 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0339] [Synthesis Example 12] Synthesis of Polymer P-12 In a 2 L flask, 10.8 g of monomer AM-6, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.1 g of CTA-12 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-12. The composition of polymer P-12 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0340] [Synthesis Example 13] Synthesis of Polymer P-13 In a 2 L flask, 10.8 g of monomer AM-6, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.1 g of CTA-13 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-13. The composition of polymer P-13 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0341] [Synthesis Example 14] Synthesis of Polymer P-14 In a 2 L flask, 10.8 g of monomer AM-6, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.3 g of CTA-14 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-14. The composition of polymer P-14 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0342] [Synthesis Example 15] Synthesis of Polymer P-15 In a 2 L flask, 10.8 g of monomer AM-6, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.2 g of CTA-15 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-15. The composition of polymer P-15 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0343] [Synthesis Example 16] Synthesis of Polymer P-16 In a 2 L flask, 10.8 g of monomer AM-6, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.2 g of CTA-16 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-16. The composition of polymer P-16 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0344] [Synthesis Example 17] Synthesis of Polymer P-17 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azimobis(isobutyrate)dimethyl and 2.8 g of CTA-17 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-17. The composition of polymer P-17 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0345] [Synthesis Example 18] Synthesis of Polymer P-18 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azimobis(isobutyrate)dimethyl and 2.7 g of CTA-18 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-18. The composition of polymer P-18 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0346] [Synthesis Example 19] Synthesis of Polymer P-19 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.6 g of CTA-19 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-19. The composition of polymer P-19 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0347] [Synthesis Example 20] Synthesis of Polymer P-20 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 3.0 g of CTA-20 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-20. The composition of polymer P-20 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0348] [Synthesis Example 21] Synthesis of Polymer P-21 In a 2 L flask, 6.6 g of monomer AM-7, 4.4 g of monomer AM-9, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.4 g of CTA-21 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-21. The composition of polymer P-21 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0349] [Synthesis Example 22] Synthesis of Polymer P-22 In a 2 L flask, 8.9 g of monomer AM-8, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.7 g of CTA-22 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-22. The composition of polymer P-22 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0350] [Synthesis Example 23] Synthesis of Polymer P-23 In a 2 L flask, 4.2 g of 1-methyl-1-cyclopentyl methacrylate, 4.5 g of monomer AM-10, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.5 g of CTA-23 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-23. The composition of polymer P-23 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0351] [Synthesis Example 24] Synthesis of Polymer P-24 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 3.0 g of CTA-24 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-24. The composition of polymer P-24 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0352] [Synthesis Example 25] Synthesis of Polymer P-25 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.3 g of CTA-25 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-25. The composition of polymer P-25 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0353] [Synthesis Example 26] Synthesis of Polymer P-26 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azobis(isobutyrate)dimethyl and 2.7 g of CTA-26 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-26. The composition of polymer P-26 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0354] [Synthesis Example 27] Synthesis of Polymer P-27 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After raising the temperature to room temperature, 1.2 g of 2,2'-azimobis(isobutyrate)dimethyl and 3.2 g of CTA-27 were added as polymerization initiators, and the temperature was raised to 60°C and the reaction was allowed to proceed for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-27. The composition of polymer P-27 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0355] [Comparative Synthesis Example 1] Synthesis of comparative polymer cP-1 The comparative polymer cP-1 was obtained using the same method as in Synthesis Example 1, except that CTA-1 was not used. The composition of comparative polymer cP-1 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0356] [Comparative Synthesis Example 2] Synthesis of comparative polymer cP-2 Comparative polymer cP-2 was obtained in the same manner as in Synthesis Example 1, except that 2-mercaptoaminoethane was used as a chain transfer agent instead of CTA-1. The composition of comparative polymer cP-2 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0357] [Comparative Synthesis Example 3] Synthesis of Comparative Polymer cP-3 The comparative polymer cP-3 was obtained using the same method as in Synthesis Example 2, except that CTA-2 was not used. The composition of comparative polymer cP-3 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0358] [2] Preparation and evaluation of positive resist materials [Examples 1-29, Comparative Examples 1-3] (1) Preparation of positive-type resist material Positive-type resist materials were prepared by dissolving each component in a solvent containing 50 ppm of PolyFox PF-636 surfactant manufactured by Omnova, according to the compositions shown in Tables 1-3, and filtering the solution through a 0.02 μm high-density polyethylene filter.

[0359] The components in Tables 1-3 are as follows: • Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) DAA (Diacetone Alcohol) EL (DL-1:1 mixed ethyl lactate)

[0360] • Acid generators: PAG-1, PAG-2 [ka]

[0361] • Quencher: Q-1~Q-3 [ka]

[0362] (2) EUV lithography evaluation Each positive-type resist material shown in Tables 1-3 was spin-coated onto a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content 43 mass%) manufactured by Shin-Etsu Chemical Co., Ltd. had been formed to a thickness of 20 nm. A resist film with a thickness of 60 nm was fabricated by pre-baking at 105°C for 60 seconds using a hot plate. The resist film was exposed using an ASML EUV scanner NXE3400 (NA 0.33, σ 0.9 / 0.6, quadruple pole illumination, wafer-mounted dimensions of a 46 nm pitch hole pattern mask with a +20% bias). PEB was performed on a hot plate at the temperatures listed in Tables 1-3 for 60 seconds, and development was performed with a 2.38 mass% TMAH aqueous solution for 30 seconds to obtain a hole pattern with dimensions of 23 nm. The exposure amount when each hole was formed with a dimension of 23 nm was measured and defined as the sensitivity. Additionally, the dimensions of 50 holes were measured using a Hitachi High-Tech SEM (CG6300), and the CDU was calculated as three times the standard deviation (σ) obtained from these measurements (3σ). The results are shown in Tables 1-3.

[0363] [Table 1]

[0364] [Table 2]

[0365] [Table 3]

[0366] As shown in Tables 1-3, the positive-type resist material of the present invention, which uses a base polymer whose ends are sealed with a salt consisting of an ammonium cation linked to a sulfide group and an anion containing a fluorine atom, exhibited good CDU.

Claims

1. A chemically amplified positive-type resist material comprising a base polymer whose ends are sealed with a salt consisting of an ammonium cation linked to a sulfide group and an anion containing a fluorine atom, The structure of the terminal is represented by the following formula (a): A chemically amplified positive-type resist material wherein the positive-type resist material further contains a photoacid generator, or the base polymer contains repeating units represented by any of the following formulas (d1) to (d3). 【Chemistry 1】 (In the formula, X1 is a hydrocarbylene group having 1 to 20 carbon atoms, and the hydrocarbylene group may include at least one selected from a hydroxyl group, an ether bond, an ester bond, a carbonate bond, a urethane bond, a lactone ring, a sultone ring, and a halogen atom.) R1 to R3 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 24 carbon atoms, and the hydrocarbyl group may contain at least one selected from a halogen atom, a hydroxyl group, a carboxyl group, an ether bond, an ester bond, a thioether bond, a thioester bond, a thionoester bond, a dithioester bond, an amino group, a hydrazide group, a nitro group, and a cyano group. X1 and at least two of R1 to R3 may bond to each other to form a ring with the nitrogen atom to which they are bonded, and R1 and R2 may combine to form =C(R1A)(R2A). R1A and R2A are each independently a hydrogen atom or a hydrocarbyl group having 1 to 16 carbon atoms, and the hydrocarbyl group may contain an oxygen atom, a sulfur atom, or a nitrogen atom. Furthermore, R2A and R3 may bond to each other to form a ring with the carbon and nitrogen atoms to which they are bonded, and this ring may contain a double bond, an oxygen atom, a sulfur atom, or a nitrogen atom. Mq- is a carboxylic acid anion having a fluorine atom, a phenoxide anion having a fluorine atom, a sulfonamide anion having a fluorine atom, a 1,1,1,3,3,3-hexafluoro-2-propoxide anion having a fluorine atom, a 1,3-diketone anion having a fluorine atom, a β-ketoester anion having a fluorine atom, or an imide anion having a fluorine atom. The dashed lines represent connecting moves. 【Chemistry 2】 (In the formula, R A is independently either a hydrogen atom or a methyl group.) Z1 is a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, or -O-Z11-, -C(=O)-O-Z11-, or -C(=O)-NH-Z11-. Z11 is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z2 is either a single bond or an ester bond. Z3 is a single bond, -Z31-C(=O)-O-, -Z31-O-, or -Z31-O-C(=O)-. Z31 is an aliphatic hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, a bromine atom, or an iodine atom. Z4 is a methylene group, a 2,2,2-trifluoro-1,1-ethanediyl group, or a carbonyl group. Z 5 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -O-Z 51-, -C(=O)-O-Z 51-, or -C(=O)-NH-Z 51-. Z 51 is a phenylene group substituted with an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, a halogen atom, or a hydroxyl group. R21 to R28 are each independently a C1 to C20 hydrocarbyl group which may contain a halogen atom or a heteroatom. Furthermore, R23 and R24 or R26 and R27 may bond to each other to form a ring with the sulfur atom to which they are bonded. M- is a non-nucleophilic counterion.

2. The chemically amplified positive resist material according to claim 1, wherein the carboxylic acid anion having a fluorine atom is represented by the following formula (a)-1, the phenoxide anion having a fluorine atom is represented by the following formula (a)-2, the sulfonamide anion having a fluorine atom is represented by the following formula (a)-3, the 1,1,1,3,3,3-hexafluoro-2-propoxide anion having a fluorine atom is represented by the following formula (a)-4, and the 1,3-diketone anion having a fluorine atom, the β-ketoester anion having a fluorine atom, or the imide anion having a fluorine atom is represented by the following formula (a)-5. 【Transformation 3】 (In the formula, R 4 and R 6 Each of these is independently a fluorine atom or a fluorinated hydrocarbyl group having 1 to 30 carbon atoms, and the fluorinated hydrocarbyl group may contain at least one selected from an ester bond, a lactone ring, an ether bond, a carbonate bond, a thioether bond, a hydroxyl group, an amino group, a nitro group, a cyano group, a sulfo group, a sulfonic acid ester bond, a chlorine atom, and a bromine atom. Rf is a fluorine atom, a trifluoromethyl group, or a 1,1,1-trifluoro-2-propanol group. R 5 These are a chlorine atom, a bromine atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbyloxycarbonyl group having 2 to 6 carbon atoms, a cyano group, an amino group, or a nitro group. R 7 This is a hydrocarbyl group having 1 to 30 carbon atoms, which may contain a hydrogen atom or a heteroatom. R 8 This is a trifluoromethyl group, a C1-C20 hydrocarbyloxy group, or a C2-C21 hydrocarbyloxycarbonyl group, and the hydrocarbyl portion of the hydrocarbyloxy group or hydrocarbyloxycarbonyl group may contain at least one selected from a carbonyl group, an ether bond, an ester bond, a thiol group, a cyano group, a nitro group, a hydroxyl group, a sultone group, a sulfonic acid ester bond, an amide bond, and a halogen atom. R 9 and R 10 are each independently an alkyl group having 1 to 10 carbon atoms or a phenyl group, and one or more of the hydrogen atoms of one or both of R 9 and R 10 are substituted with fluorine atoms. X is either -C(H) = or -N =. m and n are integers satisfying 1 ≤ m ≤ 5, 0 ≤ n ≤ 3, and 1 ≤ m + n ≤ 5.

3. The chemically amplified positive resist material according to claim 1, wherein the base polymer comprises a base polymer having a repeating unit b1 in which a hydrogen atom of a carboxyl group is substituted with an acid-unstable group, or a repeating unit b2 in which a hydrogen atom of a phenolic hydroxyl group is substituted with an acid-unstable group.

4. The chemically amplified positive resist material according to claim 3, wherein the repeating unit b1 is represented by the following formula (b1), and the repeating unit b2 is represented by the following formula (b2). 【Transformation 5】 (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. Y 1 This is a linking group having 1 to 12 carbon atoms, containing at least one of a single bond, a phenylene group or a naphthylene group, or an ester bond, an ether bond, and a lactone ring. Y 2 These are single bonds, ester bonds, or amide bonds. Y 3 These are single bonds, ether bonds, or ester bonds. R 11 and R 12 These are, independently, acid-unstable groups. R 13 This is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R 14 This is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may contain an ether bond or an ester bond. a is either 1 or 2. b is an integer between 0 and 4, where 1 ≤ a + b ≤ 5.

5. The chemically amplified positive resist material according to claim 1, wherein the base polymer further comprises repeating units c comprising an adhesion group selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonic acid ester bond, a cyano group, an amide bond, -O-C(=O)-S-, and -O-C(=O)-NH-.

6. Furthermore, the chemically amplified positive resist material according to claim 1, further comprising an organic solvent.

7. Furthermore, the chemically amplified positive resist material according to claim 1, further comprising a quencher.

8. Furthermore, the chemically amplified positive resist material according to claim 1, further comprising a surfactant.

9. A pattern forming method comprising the steps of: forming a resist film on a substrate using a chemically amplified positive resist material according to any one of claims 1 to 8; exposing the resist film with a high-energy beam; and developing the exposed resist film using a developer.

10. The pattern forming method according to claim 9, wherein the high-energy ray is an i-ray, KrF excimer laser light, ArF excimer laser light, an electron beam, or extreme ultraviolet light with a wavelength of 3 to 15 nm.

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