Resist material and pattern forming method

Abstract

To provide a resist material having high sensitivity, low LWR and low CDU regardless of whether it is used as a positive resist material or a negative resist material, and a pattern forming process using the same.SOLUTION: A resist material comprises a base polymer, and a quencher containing a salt compound represented by the formula (A) in the figure.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] As LSIs become more highly integrated and faster, pattern rules are becoming finer at a rapid pace. In particular, the expansion of the logic memory market due to the spread of smartphones is driving miniaturization. The most advanced miniaturization technology is the mass production of 10nm node devices using double patterning with ArF immersion lithography, and preparations are underway for the mass production of 7nm node devices using double patterning for the next generation. Extreme ultraviolet (EUV) lithography is being considered as a candidate for the next-generation 5nm node.

[0003] As miniaturization progresses and approaches the diffraction limit of light, the contrast of light decreases. This decrease in contrast of light causes a decrease in the resolution of hole patterns and trench patterns and a decrease in the focus margin in positive resist films. To prevent the decrease in resolution of resist patterns caused by the decrease in contrast of light, attempts are being made to improve the dissolution contrast of resist films.

[0004] For chemically amplified positive resist materials that contain an acid generator and generate an acid by irradiation with light or an electron beam (EB) to cause a deprotection reaction by the acid, and for chemically amplified negative resist materials that cause a polarity change reaction or a crosslinking reaction by the acid, the addition of a quencher to control the diffusion of the acid to the unexposed area and improve the contrast has been very effective. For this reason, many amine quenchers have been proposed (Patent Documents 1 to 3).

[0005] A resist material containing aniline substituted with iodine atoms as a quencher has been proposed (Patent Document 4). However, aniline has low basicity, and therefore the effect of suppressing acid diffusion is insufficient. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-194776 A [Patent Document 2] JP 2002-226470 A [Patent Document 3] JP 2002-363148 A [Patent Document 4] JP 2018-97356 A Summary of the Invention [Problem to be solved by the invention]

[0007] In acid-catalyzed chemically amplified resist materials, there is a need for the development of a quencher that can reduce line edge roughness (LWR) and hole dimension uniformity (CDU) while also improving sensitivity.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resist material, whether a positive resist material or a negative resist material, that has high sensitivity and small LWR and CDU, and a pattern formation method using the same. [Means for solving the problem]

[0009] Means for Solving the Problems The present inventors have conducted extensive research in order to achieve the above-mentioned object, and as a result have found that by using a salt compound containing a nitrogen-containing cation having a hydrocarbyl group substituted with an iodine atom or a bromine atom (but not containing an aromatic ring substituted with an iodine atom or a bromine atom) as a quencher, it is possible to obtain a resist material which has small LWR and CDU, high contrast, excellent resolution, and a wide process margin, and have completed the present invention.

[0010] That is, the present invention provides the following resist material and pattern forming method. 1. A resist material comprising a base polymer and a quencher comprising a salt compound represented by the following formula (A): [ka] (In the formula, m 1 is 1 or 2. 2 is an integer of 1 to 3. n is an integer of 1 to 3. j is an integer of 1 to 3. k is 1 or 2. X BI is an iodine atom or a bromine atom. R ah is a (j+1)-valent aliphatic hydrocarbon group having 1 to 20 carbon atoms, and may contain at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate group, a halogen atom other than an iodine atom, an aryl group having 6 to 12 carbon atoms, a hydroxy group, and a carboxy group. X 1 is a single bond, an ether bond, an ester bond, an amide bond, a carbonyl group or a carbonate group. R 1 is a single bond, or a C1 to C20 alkyl group which may contain an ether bond, an ester bond, or a hydroxyl group; 1 +1)valent hydrocarbon group. R 2 is a single bond or a carbon number of 1 to 20 (m 2 The hydrocarbon group may contain at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate group, a halogen atom other than an iodine atom, a hydroxy group, and a carboxy group. R 3 is a hydrogen atom, a nitro group, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyloxycarbonyl group having 2 to 20 carbon atoms, and the hydrocarbyl portion of the hydrocarbyl group or the hydrocarbyloxycarbonyl group may contain at least one selected from a hydroxy group, a carboxy group, a thiol group, an ether bond, an ester bond, a sulfonyl group, a nitro group, a cyano group, a halogen atom, and an amino group.3 may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and in this case, the ring may contain a double bond, an oxygen atom, a sulfur atom, or a nitrogen atom. 3 and R 1 may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and in this case, the ring may contain a double bond, an oxygen atom, a sulfur atom or a nitrogen atom. A k- is a carboxylate anion, a sulfonimide anion not containing a fluorine atom, a sulfonamide anion, or a halide ion. 2. The resist material of 1, further comprising an acid generator that generates a sulfonic acid, an imide acid or a methide acid. 3. The resist material of 1 or 2 further comprising an organic solvent. 4. The resist material of any one of 1 to 3, wherein the base polymer contains a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2): [ka] (In the formula, R A are each independently a hydrogen atom or a methyl group. R 11 and R 12 are each independently an acid labile group. Y 1 is a linking group having 1 to 12 carbon atoms and containing at least one type selected from a single bond, a phenylene group, a naphthylene group, an ester bond, and a lactone ring. Y 2 is a single bond or an ester bond. 5. The resist material of 4, which is a chemically amplified positive resist material. 6. The resist material of any one of 1 to 3, wherein the base polymer does not contain an acid labile group. 7. The resist material of 6, which is a chemically amplified negative resist material. 8. A resist material according to any one of 1 to 7, further comprising a surfactant. 9. The resist material of any one of 1 to 8, wherein the base polymer further contains at least one repeating unit selected from those represented by the following formulas (f1) to (f3): [ka] (In the formula, R A are each independently a hydrogen atom or a methyl group. Z 1 represents 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 groups, or -OZ 11 -, -C(=O)-OZ 11 - or -C(=O)-NH-Z 11 -It is. 11 represents an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group obtained by combining these and having 7 to 18 carbon atoms, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. Z 2 is a single bond, -Z 21 -C(=O)-O-, -Z 21 -O- or -Z 21 -OC(=O)-. Z 21 is a saturated hydrocarbylene group having 1 to 12 carbon atoms, which may contain a carbonyl group, an ester bond or an ether bond. Z 3 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, -OZ 31 -, -C(=O)-OZ 31 - or -C(=O)-NH-Z 31 -It is. 31 represents an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. R 21 ~R 28 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom.23 and R 24 or R 26 and R 27 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. R HF is a hydrogen atom or a trifluoromethyl group. M - is a non-nucleophilic counterion. 10. A pattern forming method comprising the steps of forming a resist film on a substrate using a resist material according to any one of 1 to 9, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developer. 11. The pattern formation method according to claim 10, wherein the high-energy radiation is ArF excimer laser light having a wavelength of 193 nm or KrF excimer laser light having a wavelength of 248 nm. 12. The pattern formation method according to claim 10, wherein the high energy radiation is EB or EUV having a wavelength of 3 to 15 nm. Effect of the Invention

[0011] The salt compound represented by formula (A) has a large absorption of EUV light due to the presence of iodine and bromine atoms, which has a sensitizing effect. In addition, the atomic weight of the iodine and bromine atoms is large, which has a high effect of suppressing acid diffusion. Since it is not photosensitive and does not decompose even in the exposed area, it has a high acid diffusion control ability in the exposed area and can suppress film loss of the pattern by using an alkaline developer. This makes it possible to improve sensitivity and reduce LWR and CDU. This makes it possible to construct a resist material with high sensitivity, low LWR, and low CDU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [Salt compounds containing nitrogen-containing cations] The resist material of the present invention contains a salt compound represented by the following formula (A): [ka]

[0013] In formula (A), m 1 is 1 or 2. 2 is an integer of 1 to 3. n is an integer of 1 to 3. j is an integer of 1 to 3. k is 1 or 2.

[0014] In formula (A), X BI is an iodine atom or a bromine atom. 1 , m 2 , when n and / or j are 2 or 3, each X BI may be the same or different from each other.

[0015] In formula (A), R ah is a (j+1)-valent aliphatic hydrocarbon group having 1 to 20 carbon atoms, and may contain at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate group, a halogen atom other than an iodine atom, an aryl group having 6 to 12 carbon atoms, a hydroxy group, and a carboxy group.

[0016] The aliphatic hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic.Specific examples thereof include a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-1,3-diyl group, a propane-2,2-diyl group, a butane-1,1-diyl group, a butane-1,2-diyl group, a butane-1,3-diyl group, a butane-2,3-diyl group, a butane-1,4-diyl group, a 1,1-dimethylethane-1,2-diyl group, a pentane-1,5-diyl group, a 2-methylbutane-1,2-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, a hexane-2,3-diyl group, a hexane-1,8-diyl group, a hexane-3,4-diyl group, a hexane-4,5-diyl group, a hexane-5,6-diyl group, a hexane-6,7-diyl group, a hexane-8,5-diyl group, a hexane-9,6-diyl group, a hexane-10,7-diyl group, a hexane-11,7-diyl group, a hexane-12,7-diyl group, a hexane-13,7-diyl group, a hexane-14,7-diyl group, a hexane-15,7-diyl group, a hexane-16,7-diyl group, a hexane-17,7-diyl group, a hexane-20,7-diyl group, a hexane-22,7-diyl group, a hexane-23,7-diyl group, a hexane-24,7-diyl group, a hexane-25,7-diyl group, a hexane-26,7-diyl group, a hexane-27,7-diyl group, a hexane-2 alkanediyl groups such as 1,8-diyl, octane-1,9-diyl, nonane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl groups; cyclopropane-1,1-diyl, cyclopropane-1,2-diyl, cyclobutane-1,1-diyl, cyclobutane-1,2-diyl, cyclobutane-1,3-diyl, cyclopentane-1,1-diyl, cyclopentane-1,2-diyl, cyclopentane-1,3-diyl, cyclohexane-1,1-diyl, and cyclohexene-1,1-diyl groups. Cycloalkanediyl groups such as cyclohexane-1,2-diyl, cyclohexane-1,3-diyl, and cyclohexane-1,4-diyl; polycyclic saturated hydrocarbylene groups such as norbornane-2,3-diyl and norbornane-2,6-diyl; alkenediyl groups such as 2-propene-1,1-diyl; alkynediyl groups such as 2-propyne-1,1-diyl; cycloalkenediyl groups such as 2-cyclohexene-1,2-diyl, 2-cyclohexene-1,3-diyl, and 3-cyclohexene-1,2-diyl; 5-norbornene-2,3- Examples of the hydrocarbylene group include polycyclic unsaturated aliphatic hydrocarbylene groups such as a diyl group; alkanediyl groups substituted with a cyclic aliphatic hydrocarbylene group such as a cyclopentylmethanediyl group, a cyclohexylmethanediyl group, a 2-cyclopentenylmethanediyl group, a 3-cyclopentenylmethanediyl group, a 2-cyclohexenylmethanediyl group, or a 3-cyclohexenylmethanediyl group; aliphatic hydrocarbylene groups such as groups obtained by combining these; and trivalent or tetravalent groups obtained by further eliminating one or two hydrogen atoms from the above-mentioned aliphatic hydrocarbylene groups.

[0017] Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a 1-naphthyl group, and a 2-naphthyl group.

[0018] In formula (A), X 1 is a single bond, an ether bond, an ester bond, an amide bond, a carbonyl group or a carbonate group.

[0019] In formula (A), R 1 is a single bond, or a C1 to C20 alkyl group which may contain an ether bond, an ester bond, or a hydroxyl group; 1 +1)valent hydrocarbon group. 2 is a single bond or a carbon number of 1 to 20 (m 2 The hydrocarbon group may contain at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate group, a halogen atom other than an iodine atom, a hydroxy group, and a carboxy group.

[0020] R 1 Expressed as (m 1 The hydrocarbon group with a valence of +1 is derived from the hydrocarbon (m 1 +1) hydrogen atoms are eliminated, and R 2 Expressed as (m 2 The hydrocarbon group with a valence of +1 is (m 2+1) hydrogen atoms are eliminated. The hydrocarbon may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkanes such as methane, ethane, propane, butane, 2-methylpropane, pentane, 2-methylbutane, hexane, heptane, octane, nonane, decane, undecane, and dodecane; cyclic saturated hydrocarbons such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, norbornane, and adamantane; alkenes such as ethylene, propene, 1-butene, 2-butene, and 2-methylpropene; cyclic unsaturated hydrocarbons such as cyclohexene and norbornene; aromatic hydrocarbons such as benzene, naphthalene, toluene, xylene, and anthracene; and compounds in which some or all of the hydrogen atoms of these groups are substituted with hydrocarbyl groups.

[0021] In formula (A), R 3is a hydrogen atom, a nitro group, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyloxycarbonyl group having 2 to 20 carbon atoms. The hydrocarbyl group and the hydrocarbyloxycarbonyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, or an icosyl group; saturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclopropylmethyl group, a 4-methylcyclohexyl group, a cyclohexylmethyl group, a norbornyl group, or an adamantyl group; alkenyl groups having 2 to 20 carbon atoms, such as a vinyl group, a propenyl group, a butenyl group, or a hexenyl group; and a cyclohexenyl group and a norbornenyl group. unsaturated cyclic aliphatic hydrocarbyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, and butynyl; aryl groups having 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; aralkyl groups having 7 to 20 carbon atoms, such as benzyl and phenethyl; and groups obtained by combining these, such as 2-cyclohexylethynyl and 2-phenylethynyl. The hydrocarbyl group may contain at least one selected from a hydroxy group, a carboxy group, a thiol group, an ether bond, an ester bond, a sulfonyl group, a nitro group, a cyano group, a halogen atom, and an amino group.

[0022] When n is 1, two R 3may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and in this case, the ring may contain a double bond, an oxygen atom, a sulfur atom, or a nitrogen atom. 3 and R 1 may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and in this case, the ring may contain a double bond, an oxygen atom, a sulfur atom or a nitrogen atom.

[0023] Examples of cations of the salt compound represented by formula (A) include, but are not limited to, those shown below. [ka]

[0024] [ka]

[0025] [ka]

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] [ka]

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[0063] [ka]

[0064] [ka]

[0065] In formula (A), A k- is a carboxylate anion, a sulfonimide anion not containing a fluorine atom, a sulfonamide anion or a halide ion.

[0066] The carboxylate anion is preferably one represented by the following formula (Aa-1) or (Aa-2). The sulfonimide anion not containing a fluorine atom is preferably one represented by the following formula (Ab). The sulfonamide anion is preferably one represented by the following formula (Ac). [ka]

[0067] In formula (Aa-1), R a1is a hydrogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include an alkyl group having 1 to 30 carbon atoms, a cyclic saturated hydrocarbyl group having 3 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, a cyclic unsaturated aliphatic hydrocarbyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, and groups obtained by combining these groups. In addition, a portion of the hydrogen atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and a portion of the carbon atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, so that the group may contain an ester bond, an ether bond, a sulfide bond, a sulfoxide group, a carbonate group, a carbamate group, a sulfone group, an amino group, an amide bond, a hydroxy group, a thiol group, a nitro group, a halogen atom, or the like.

[0068] In formula (Aa-2), R a2 is a single bond or a hydrocarbylene group having 1 to 30 carbon atoms which may contain a heteroatom. The hydrocarbylene group may be linear, branched or cyclic, and specific examples thereof include an alkanediyl group having 1 to 30 carbon atoms, a cyclic saturated hydrocarbylene group having 3 to 30 carbon atoms, an alkenediyl group having 2 to 30 carbon atoms, an alkynediyl group having 2 to 30 carbon atoms, a cyclic unsaturated aliphatic hydrocarbylene group having 3 to 30 carbon atoms, an arylene group having 6 to 20 carbon atoms, and groups obtained by combining these. In addition, a portion of the hydrogen atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and a portion of the carbon atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, so that the group may contain an ester bond, an ether bond, a sulfide bond, a sulfoxide group, a carbonate group, a carbamate group, a sulfone group, an amino group, an amide bond, a hydroxy group, a thiol group, a nitro group, a halogen atom, or the like.

[0069] In formula (Ab), R b1 and R b2 are each independently a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a hydroxy group, an ether bond, or an ester bond. b1 and R b2 and may be bonded to each other to form a ring. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include an alkyl group having 1 to 20 carbon atoms, a cyclic saturated hydrocarbyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a cyclic unsaturated aliphatic hydrocarbyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, and groups obtained by combining these groups.

[0070] In formula (Ac), R c1 R is a fluorine atom, a hydrocarbyl group having 1 to 10 carbon atoms, or a fluorinated hydrocarbyl group having 1 to 10 carbon atoms, and may contain a hydroxy group, an ether bond, or an ester bond. c2 is a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms, which may contain a hydroxy group, an ether bond, or an ester bond. c1 and R c2 and may be bonded to each other to form a ring together with the atoms to which they are bonded. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include an alkyl group having 1 to 10 carbon atoms, a cyclic saturated hydrocarbyl group having 3 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a cyclic unsaturated aliphatic hydrocarbyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, and groups obtained by combining these groups. In addition, the fluorinated hydrocarbyl group may be a group in which some or all of the hydrogen atoms of the hydrocarbyl group are substituted with fluorine atoms.

[0071] Examples of the carboxylate anion include, but are not limited to, those shown below. [ka]

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[0083] Examples of the sulfonimide anion not containing a fluorine atom include, but are not limited to, those shown below. [ka]

[0084] The sulfonamide anions include, but are not limited to, those shown below. [ka]

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[0094] Examples of the halide ion include a fluoride ion, a chloride ion, a bromide ion, and an iodide ion.

[0095] The salt compound represented by formula (A) can be synthesized, for example, by a neutralization reaction between a nitrogen-containing compound having a hydrocarbyl group substituted with an iodine atom or a bromine atom (but not including an aromatic ring substituted with an iodine atom or a bromine atom) and a carboxylic acid, a sulfonimide not containing a fluorine atom, a sulfonamide or a hydrogen halide.

[0096] The salt compound represented by formula (A) functions as a quencher having a sensitizing effect in a resist material. A normal quencher reduces LWR and CDU by controlling acid diffusion and lowering sensitivity, but the salt compound represented by formula (A) has an acid diffusion controlling effect due to the amino group and the iodine atom or bromine atom with a large atomic weight, and also has a function of improving sensitivity due to the sensitizing effect due to the presence of iodine atoms and bromine atoms with large EUV absorption. During EB or EUV exposure, radicals are generated from the iodine atoms bonded to the hydrocarbyl group, and secondary electrons are generated from the bromine atoms, which are thought to promote the decomposition of the acid generator and increase sensitivity.

[0097] In the resist material of the present invention, the content of the salt compound represented by formula (A) is preferably 0.001 to 50 parts by mass, and more preferably 0.01 to 40 parts by mass, per 100 parts by mass of the base polymer described below, from the viewpoints of sensitivity and acid diffusion suppression effect.

[0098] The salt compound represented by formula (A) is not photosensitive and does not decompose upon exposure, and can suppress the diffusion of acid in the exposed area. In addition, since it is not a salt, it does not promote solubility in an alkaline developer, and has the effect of suppressing film loss of the pattern.

[0099] [Base polymer] In the case of a positive resist material, the base polymer contained in the resist material of the present invention contains a repeating unit containing an acid labile group. The repeating unit containing an acid labile group is preferably a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1) or a repeating unit represented by the following formula (a2) (hereinafter also referred to as repeating unit a2). [ka]

[0100] In formulas (a1) and (a2), R A R is each independently a hydrogen atom or a methyl group. 11 and R 12 are each independently an acid labile group. When the base polymer contains both repeating units a1 and a2, R 11 and R 12 may be the same or different. 1 Y is a linking group having 1 to 12 carbon atoms and containing at least one selected from a single bond, a phenylene group, a naphthylene group, an ester bond, and a lactone ring. 2 is a single bond or an ester bond.

[0101] Examples of monomers that provide the repeating unit a1 include, but are not limited to, those shown below. A and R 11 is the same as above. [ka]

[0102] Examples of monomers that provide the repeating unit a2 include, but are not limited to, those shown below. A and R 12 is the same as above. [ka]

[0103] In formulas (a1) and (a2), R 11 and R 12 Examples of the acid labile group represented by the formula (I) include those described in JP-A-2013-80033 and JP-A-2013-83821.

[0104] Typically, the acid labile group includes those represented by the following formulae (AL-1) to (AL-3). [ka] (In the formula, the dashed lines represent bonds.)

[0105] In formulas (AL-1) and (AL-2), R L1 and R L2 are each independently a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a fluorine atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. The hydrocarbyl group is preferably a saturated hydrocarbyl group having 1 to 40 carbon atoms, more preferably a saturated hydrocarbyl group having 1 to 20 carbon atoms.

[0106] In formula (AL-1), a is an integer of 0 to 10, and an integer of 1 to 5 is preferable.

[0107] In formula (AL-2), R L3 and R L4are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and may contain a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a fluorine atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. The hydrocarbyl group is preferably a saturated hydrocarbyl group having 1 to 20 carbon atoms. L2 , R L3 and R L4 Any two of these may be bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom or the carbon atom and oxygen atom to which they are bonded. As the ring, a ring having 4 to 16 carbon atoms is preferable, and an alicyclic ring is particularly preferable.

[0108] In formula (AL-3), R L5 , R L6 and R L7 are each independently a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a fluorine atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. The hydrocarbyl group is preferably a saturated hydrocarbyl group having 1 to 20 carbon atoms. L5 , R L6 and R L7 Any two of these may be bonded to each other to form, together with the carbon atom to which they are bonded, a ring having 3 to 20 carbon atoms. As the ring, a ring having 4 to 16 carbon atoms is preferred, and an alicyclic ring is particularly preferred.

[0109] The base polymer may contain a repeating unit b containing a phenolic hydroxy group as an adhesive group. Examples of monomers that provide the repeating unit b include, but are not limited to, those shown below. In the following formula, R A is the same as above. [ka]

[0110] The base polymer may further contain a repeating unit c containing a hydroxy group other than a phenolic hydroxy group, a lactone ring, an ether bond, an ester bond, a carbonyl group, a cyano group, or a carboxy group as another adhesive group. Examples of monomers that provide the repeating unit c include, but are not limited to, those shown below. In the following formula, R A is the same as above. [ka]

[0111] [ka]

[0112] [ka]

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] The base polymer may include repeat units d derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene, or derivatives thereof. Monomers that provide repeat units d include, but are not limited to, those shown below. [ka]

[0120] The base polymer may include repeat units e derived from styrene, vinyl naphthalene, vinyl anthracene, vinyl pyrene, methylene indane, vinyl pyridine, or vinyl carbazole.

[0121] The base polymer may contain a repeating unit f derived from an onium salt containing a polymerizable unsaturated bond. Preferred repeating units f include a repeating unit represented by the following formula (f1) (hereinafter also referred to as repeating unit f1), a repeating unit represented by the following formula (f2) (hereinafter also referred to as repeating unit f2), and a repeating unit represented by the following formula (f3) (hereinafter also referred to as repeating unit f3). The repeating units f1 to f3 may be used alone or in combination of two or more. [ka]

[0122] In formulas (f1) to (f3), R A are each independently a hydrogen atom or a methyl group. Z 1 represents 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 groups, or -OZ 11 -, -C(=O)-OZ 11 - or -C(=O)-NH-Z 11 -It is. 11Z 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 groups, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 is a single bond, -Z 21 -C(=O)-O-, -Z 21 -O- or -Z 21 -OC(=O)-. Z 21 is a saturated hydrocarbylene group having 1 to 12 carbon atoms, which may contain a carbonyl group, an ester bond or an ether bond. 3 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, -OZ 31 -, -C(=O)-OZ 31 - or -C(=O)-NH-Z 31 -It is. 31 is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. 11 and Z 31 The aliphatic hydrocarbylene group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. 21 The saturated hydrocarbylene group represented by the formula (I) may be linear, branched or cyclic.

[0123] In formulas (f1) to (f3), R 21 ~R 28 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 101 ~R 105 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0124] Also, R 23 and R 24 or R26 and R 27 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring may be any of the groups represented by R 101 and R 102 and , when bonded to each other, can form a ring together with the sulfur atom to which they are bonded, similar to the examples given above.

[0125] In formula (f2), R HF is a hydrogen atom or a trifluoromethyl group.

[0126] In formula (f1), M - is a non-nucleophilic counter ion. Examples of the non-nucleophilic counter ion include halide ions such as chloride ion and bromide ion, fluoroalkylsulfonate ions such as triflate ion, 1,1,1-trifluoroethanesulfonate ion and nonafluorobutanesulfonate ion, arylsulfonate ions such as tosylate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion and 1,2,3,4,5-pentafluorobenzenesulfonate ion, alkylsulfonate ions such as mesylate ion and butanesulfonate ion, imide ions such as bis(trifluoromethylsulfonyl)imide ion, bis(perfluoroethylsulfonyl)imide ion and bis(perfluorobutylsulfonyl)imide ion, and methide ions such as tris(trifluoromethylsulfonyl)methide ion and tris(perfluoroethylsulfonyl)methide ion.

[0127] Further examples of the non-nucleophilic counter ion include a sulfonate ion represented by the following formula (f1-1) in which the α-position is substituted with a fluorine atom, and a sulfonate ion represented by the following formula (f1-2) in which the α-position is substituted with a fluorine atom and the β-position is substituted with a trifluoromethyl group. [ka]

[0128] In formula (f1-1), R31 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. Specific examples thereof include R 111 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0129] In formula (f1-2), R 32 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 the hydrocarbylcarbonyl group may contain an ether bond, an ester bond, a carbonyl group, or a lactone ring. The hydrocarbyl group and the hydrocarbylcarbonyl group may have a hydrocarbyl moiety that is saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 111 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0130] Examples of the cation of the monomer that gives the repeating unit f1 include, but are not limited to, those shown below. In the following formula, R A is the same as above. [ka]

[0131] Examples of the cation of the monomer that gives the repeating unit f2 or f3 include the same as those exemplified as the cation of the sulfonium salt represented by formula (1-1) described later.

[0132] Examples of the anion of the monomer that gives the repeating unit f2 include, but are not limited to, those shown below. In the following formula, R A is the same as above. [ka]

[0133] [ka]

[0134] Examples of the anion of the monomer that gives the repeating unit f3 include, but are not limited to, those shown below. In the following formula, R A is the same as above. [ka]

[0135] [ka]

[0136] [ka]

[0137] By binding the acid generator to the polymer main chain, acid diffusion is reduced, and a decrease in resolution due to blurring caused by acid diffusion can be prevented. Furthermore, the LWR and CDU are improved by uniformly dispersing the acid generator. When a base polymer containing the repeating unit f (i.e., a polymer-bound acid generator) is used, the incorporation of an additive acid generator, which will be described later, can be omitted.

[0138] The base polymer for the positive resist material essentially contains a repeating unit a1 or a2 containing an acid-labile group. In this case, the content ratios of the repeating units a1, a2, b, c, d, e, and f are preferably 0≦a1<1.0, 0≦a2<1.0, 0<a1 + a2<1.0, 0≦b≦0.9, 0≦c≦0.9, 0≦d≦0.8, 0≦e≦0.8, and 0≦f≦0.5; more preferably 0≦a1≦0.9, 0≦a2≦0.9, 0.1≦a1 + a2≦0.9, 0≦b≦0.8, 0≦c≦0.8, 0≦d≦0.7, 0≦e≦0.7, and 0≦f≦0.4; still more preferably 0≦a1≦0.8, 0≦a2≦0.8, 0.1≦a1 + a2≦0.8, 0≦b≦0.75, 0≦c≦0.75, 0≦d≦0.6, 0≦e≦0.6, and 0≦f≦0.3. When the repeating unit f is at least one selected from the repeating units f1 to f3, f = f1 + f2 + f3. Also, a1 + a2 + b + c + d + e + f = 1.0.

[0139] On the other hand, the base polymer for the negative resist material does not necessarily require an acid-labile group. Examples of such a base polymer include those containing the repeating unit b and, if necessary, further containing the repeating units c, d, e, and / or f. The content ratios of these repeating units are preferably 0 < b≦1.0, 0≦c≦0.9, 0≦d≦0.8, 0≦e≦0.8, and 0≦f≦0.5; more preferably 0.2≦b≦1.0, 0≦c≦0.8, 0≦d≦0.7, 0≦e≦0.7, and 0≦f≦0.4; still more preferably 0.3≦b≦1.0, 0≦c≦0.75, 0≦d≦0.6, 0≦e≦0.6, and 0≦f≦0.3. When the repeating unit f is at least one selected from the repeating units f1 to f3, f = f1 + f2 + f3. Also, b + c + d + e + f = 1.0.

[0140] To synthesize the base polymer, for example, monomers that provide the above-described repeating units may be heated in an organic solvent with the addition of a radical polymerization initiator to carry out polymerization.

[0141] Examples of the organic solvent used during polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and dioxane. Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroyl peroxide. The temperature during polymerization is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, and more preferably 5 to 20 hours.

[0142] When a monomer containing a hydroxy group is copolymerized, the hydroxy group may be substituted with an acetal group that is easily deprotected by an acid, such as an ethoxyethoxy group, during polymerization, and then deprotected with a weak acid and water after polymerization; alternatively, the hydroxy group may be substituted with an acetyl group, a formyl group, a pivaloyl group, or the like, and then subjected to alkaline hydrolysis after polymerization.

[0143] When hydroxystyrene or hydroxyvinylnaphthalene is copolymerized, acetoxystyrene or acetoxyvinylnaphthalene may be used instead of hydroxystyrene or hydroxyvinylnaphthalene, and after polymerization, the acetoxy group may be deprotected by the above-mentioned alkaline hydrolysis to give hydroxystyrene or hydroxyvinylnaphthalene.

[0144] As the base for the alkaline hydrolysis, ammonia water, triethylamine, etc. can be used. 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.

[0145] The base polymer has a weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) using THF as a solvent of preferably 1,000 to 500,000, more preferably 2,000 to 30,000. If the Mw is too small, the resist material will have poor heat resistance, whereas if the Mw is too large, the alkali solubility will decrease, making the base material more susceptible to footing after pattern formation.

[0146] Furthermore, when the base polymer has a wide molecular weight distribution (Mw / Mn), low and high molecular weight polymers are present, which may result in foreign matter being found on the pattern after exposure or deterioration of the pattern shape. As the pattern rule becomes finer, the effects of Mw and Mw / Mn tend to become greater, so in order to obtain a resist material suitable for fine pattern dimensions, it is preferable that the Mw / Mn of the base polymer has a narrow distribution of 1.0 to 2.0, particularly 1.0 to 1.5.

[0147] The base polymer may include two or more polymers having different composition ratios, Mw, and Mw / Mn.

[0148] [Acid generator] The resist material of the present invention may contain an acid generator (hereinafter also referred to as an additive acid generator) that generates a strong acid. In the case of a chemically amplified positive resist material, the strong acid means a compound having sufficient acidity to cause a deprotection reaction of an acid labile group of a base polymer, and in the case of a chemically amplified negative resist material, the strong acid means a compound having sufficient acidity to cause a polarity change reaction or a crosslinking reaction by an acid. By containing such an acid generator, the salt compound represented by formula (A) functions as a quencher, and the resist material of the present invention can function as a chemically amplified positive resist material or a chemically amplified negative resist material.

[0149] The acid generator may be, for example, a compound (photoacid generator) that generates an acid in response to actinic rays or radiation. The photoacid generator may be any compound that generates an acid when irradiated with high-energy rays, but is preferably one that generates a sulfonic acid, an imide acid, or a methide acid. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate-type acid generators. Specific examples of photoacid generators include those described in paragraphs

[0122] to

[0142] of JP2008-111103A.

[0150] In addition, as the photoacid generator, a sulfonium salt represented by the following formula (1-1) or an iodonium salt represented by the following formula (1-2) can also be suitably used. [ka]

[0151] In formulas (1-1) and (1-2), R 101 ~R 105 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom.

[0152] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0153] R 101 ~R 105The hydrocarbyl group having 1 to 20 carbon atoms represented by the following formula may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, or an icosyl group; cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclopropylmethyl group, a 4-methylcyclohexyl group, a cyclohexylmethyl group, a norbornyl group, or an adamantyl group; alkenyl groups, such as a vinyl group, a propenyl group, a butenyl group, or a hexenyl group; ethynyl group, propenyl group, alkynyl groups having 2 to 20 carbon atoms, such as a norbornenyl group, butynyl group, etc.; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 20 carbon atoms, such as a cyclohexenyl group, norbornenyl group, etc.; aryl groups having 6 to 20 carbon atoms, such as a phenyl group, a methylphenyl group, an ethylphenyl group, a n-propylphenyl group, an isopropylphenyl group, a n-butylphenyl group, an isobutylphenyl group, a sec-butylphenyl group, a tert-butylphenyl group, a naphthyl group, a methylnaphthyl group, an ethylnaphthyl group, a n-propylnaphthyl group, an isopropylnaphthyl group, a n-butylnaphthyl group, an isobutylnaphthyl group, a sec-butylnaphthyl group, a tert-butylnaphthyl group, etc.; aralkyl groups having 7 to 20 carbon atoms, such as a benzyl group, a phenethyl group, etc.; and groups obtained by combining these.

[0154] In addition, some or all of the hydrogen atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the carbon atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, these groups may contain a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate group, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, or the like.

[0155] Also, R 101 and R 102 However, they may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring is preferably one having the structure shown below. [ka] (In the formula, the dashed line represents R 103 It is a combination with .)

[0156] Examples of the cation of the sulfonium salt represented by formula (1-1) include, but are not limited to, those shown below. [ka]

[0157] [ka]

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] [ka]

[0167] [ka]

[0168] [ka]

[0169] [ka]

[0170] Examples of the cation of the iodonium salt represented by formula (1-2) include, but are not limited to, those shown below. [ka]

[0171] [ka]

[0172] In formulas (1-1) and (1-2), Xa - is an anion selected from the following formulas (1A) to (1D). [ka]

[0173] In formula (1A), R fa 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. Specific examples thereof include R 111 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0174] The anion represented by formula (1A) is preferably one represented by the following formula (1A'). [ka]

[0175] In formula (1A'), R HF R is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 111 is a hydrocarbyl group having 1 to 38 carbon atoms which may contain a heteroatom. The heteroatom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, etc., and more preferably an oxygen atom. In order to obtain high resolution in the formation of a fine pattern, the hydrocarbyl group is preferably one having 6 to 30 carbon atoms.

[0176] R 111The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 38 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, a nonyl group, an undecyl group, a tridecyl group, a pentadecyl group, a heptadecyl group, and an icosanyl group; a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a 1-adamantylmethyl group, a norbornyl group, Examples of the alkyl group include cyclic saturated hydrocarbyl groups having 3 to 38 carbon atoms, such as a norbornylmethyl group, a tricyclodecanyl group, a tetracyclododecanyl group, a tetracyclododecanylmethyl group, and a dicyclohexylmethyl group; unsaturated aliphatic hydrocarbyl groups having 2 to 38 carbon atoms, such as an allyl group and a 3-cyclohexenyl group; aryl groups having 6 to 38 carbon atoms, such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group; aralkyl groups having 7 to 38 carbon atoms, such as a benzyl group and a diphenylmethyl group; and groups obtained by combining these groups.

[0177] In addition, some or all of the hydrogen atoms of these groups may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the carbon atoms of these groups may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, resulting in the group containing a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate group, 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, and a 3-oxocyclohexyl group.

[0178] Synthesis of sulfonium salts containing an anion represented by formula (1A') is described in detail in JP-A-2007-145797, JP-A-2008-106045, JP-A-2009-7327, JP-A-2009-258695, etc. In addition, sulfonium salts described in JP-A-2010-215608, JP-A-2012-41320, JP-A-2012-106986, JP-A-2012-153644, etc. are also preferably used.

[0179] Examples of the anion represented by formula (1A) include, but are not limited to, those shown below: In the following formula, Ac is an acetyl group. [ka]

[0180] [ka]

[0181] [ka]

[0182] [ka]

[0183] In formula (1B), R fb1 and R fb2 are each independently 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. Specific examples thereof include R 111 Examples of the hydrocarbyl group represented by the formula R include the same as those exemplified above. fb1 and R fb2 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 and R fb2means that the groups (-CF2-SO2-N - -SO2-CF2-) may form a ring, in which case, R fb1 and R fb2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0184] In formula (1C), R fc1 , R fc2 and R fc3 are each independently 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. Specific examples thereof include R 111 Examples of the hydrocarbyl group represented by the formula R include the same as those exemplified above. fc1 , R fc2 and R fc3 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 and R fc2 means that the groups (-CF2-SO2-C - -SO2-CF2-) may form a ring, in which case, R fc1 and R fc2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0185] In formula (1D), R fd is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 111 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0186] The synthesis of a sulfonium salt containing an anion represented by formula (1D) is described in detail in JP-A-2010-215608 and JP-A-2014-133723.

[0187] Examples of the anion represented by formula (1D) include, but are not limited to, those shown below. [ka]

[0188] [ka]

[0189] Although the photoacid generator containing the anion represented by formula (1D) does not have a fluorine atom at the α-position of the sulfo group, it has two trifluoromethyl groups at the β-position, and therefore has sufficient acidity to cleave the acid labile group in the base polymer, and can therefore be used as a photoacid generator.

[0190] As the photoacid generator, a compound represented by the following formula (2) can also be suitably used. [ka]

[0191] In formula (2), R 201 and R 202 R are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. 203 is a hydrocarbylene group having 1 to 30 carbon atoms which may contain a heteroatom. 201 , R 202 and R 203 Any two of may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring is as defined in the description of formula (1-1) as R 101 and R 102 and , when bonded to each other, can form a ring together with the sulfur atom to which they are bonded, similar to those exemplified above.

[0192] R 201 and R 202The hydrocarbyl group represented by the formula (1) may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl and n-decyl groups; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, oxanorbornyl and tricyclo[5.2.1.0]. 2,6 cyclic saturated hydrocarbyl groups having 3 to 30 carbon atoms, such as a decanyl group, and an adamantyl group; aryl groups having 6 to 30 carbon atoms, such as a phenyl group, a methylphenyl group, an ethylphenyl group, an n-propylphenyl group, an isopropylphenyl group, an n-butylphenyl group, an isobutylphenyl group, a sec-butylphenyl group, a tert-butylphenyl group, a naphthyl group, a methylnaphthyl group, an ethylnaphthyl group, an n-propylnaphthyl group, an isopropylnaphthyl group, an n-butylnaphthyl group, an isobutylnaphthyl group, a sec-butylnaphthyl group, a tert-butylnaphthyl group, and an anthracenyl group; and groups obtained by combining these groups. In addition, some or all of the hydrogen atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the carbon atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, these groups may contain a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate group, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, or the like.

[0193] R 203The hydrocarbylene group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkanediyl groups having 1 to 30 carbon atoms, such as a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, and a heptadecane-1,17-diyl group; a cyclopentanediyl group, a cyclohexanediyl group, and the like. Examples of the alkylene groups include cyclic saturated hydrocarbylene groups having 3 to 30 carbon atoms, such as axanediyl group, norbornanediyl group, and adamantanediyl group; arylene groups having 6 to 30 carbon atoms, such as a phenylene group, a methylphenylene group, an ethylphenylene group, an n-propylphenylene group, an isopropylphenylene group, an n-butylphenylene group, an isobutylphenylene group, a sec-butylphenylene group, a tert-butylphenylene group, a naphthylene group, a methylnaphthylene group, an ethylnaphthylene group, an n-propylnaphthylene group, an isopropylnaphthylene group, an n-butylnaphthylene group, an isobutylnaphthylene group, a sec-butylnaphthylene group, and a tert-butylnaphthylene group; and groups obtained by combining these groups. In addition, some or all of the hydrogen atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, or some of the carbon atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the group may contain a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate group, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, etc. As the heteroatom, an oxygen atom is preferable.

[0194] In formula (2), L Ais a hydrocarbylene group having 1 to 20 carbon atoms which may contain a single bond, an ether bond, or a heteroatom. The hydrocarbylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 203 Examples of the hydrocarbylene group represented by the formula (I) include the same as those exemplified above.

[0195] In formula (2), X A , X B , X C and X D are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. A , X B , X C and X D At least one of the groups is a fluorine atom or a trifluoromethyl group.

[0196] In the formula (2), d is an integer of 0 to 3.

[0197] The photoacid generator represented by formula (2) is preferably one represented by the following formula (2'). [ka]

[0198] In formula (2'), L A is 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 are each 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. Specific examples thereof include R 111 Examples of the hydrocarbyl group represented by the formula: x and y each independently represent an integer of 0 to 5, and z represents an integer of 0 to 4.

[0199] Examples of the photoacid generator represented by formula (2) include the same as those exemplified as the photoacid generator represented by formula (2) in JP2017-026980A.

[0200] Among the photoacid generators, those containing an anion represented by formula (1A') or (1D) are particularly preferred because of their small acid diffusion and excellent solubility in solvents, while those represented by formula (2') are particularly preferred because of their extremely small acid diffusion.

[0201] The photoacid generator may be a sulfonium salt or an iodonium salt having an anion containing an aromatic ring substituted with an iodine atom or a bromine atom. Examples of such salts include those represented by the following formula (3-1) or (3-2). [ka]

[0202] In formulas (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, more preferably 2 or 3. r is preferably an integer satisfying 0≦r≦2.

[0203] In formulas (3-1) and (3-2), X BI represents an iodine atom or a bromine atom, and when p and / or q are 2 or more, they may be the same or different.

[0204] In formulas (3-1) and (3-2), L 1 is a single bond, an ether bond or an ester bond, or a saturated hydrocarbylene group having 1 to 6 carbon atoms which may contain an ether bond or an ester bond. The saturated hydrocarbylene group may be linear, branched or cyclic.

[0205] In formulas (3-1) and (3-2), L 2represents a single bond or a divalent linking group having 1 to 20 carbon atoms when p is 1, and represents a (p+1)-valent linking group having 1 to 20 carbon atoms when p is 2 or 3, and the linking group may contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0206] In formulas (3-1) and (3-2), R 401 is a hydroxy group, a carboxy group, a fluorine atom, a chlorine atom, a bromine atom or an amino group, or a saturated hydrocarbyl group having 1 to 20 carbon atoms, a saturated hydrocarbyloxy group having 1 to 20 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 20 carbon atoms, a saturated hydrocarbyloxycarbonyl group having 2 to 10 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms or a saturated hydrocarbylsulfonyloxy group having 1 to 20 carbon atoms which may contain a fluorine atom, a chlorine atom, a bromine atom, a hydroxy group, an amino group or an ether bond, or 401A )(R 401B ), -N(R 401C )-C(=O)-R 401D Or -N(R 401C )-C(=O)-OR 401D R 401A and R 401B R are each 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 contain a halogen atom, a hydroxy 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. 401Dis an aliphatic hydrocarbyl group having 1 to 16 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may contain a halogen atom, a hydroxy 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 saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbyloxycarbonyl group, saturated hydrocarbylcarbonyl group, and saturated hydrocarbylcarbonyloxy group may be linear, branched, or cyclic. When p and / or r is 2 or more, each R 401 may be the same or different from each other.

[0207] Of these, R 401 Examples of the hydroxyl group include -N(R 401C )-C(=O)-R 401D , -N(R 401C )-C(=O)-OR 401D , a fluorine atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group, and the like are preferred.

[0208] In formulas (3-1) and (3-2), Rf 1 ~Rf 4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, at least one of which is a fluorine atom or a trifluoromethyl group. 1 and Rf 2 may combine to form a carbonyl group. 3 and Rf 4 are preferably both fluorine atoms.

[0209] In formulas (3-1) and (3-2), R 402 ~R 406are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 101 ~R 105 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above. In addition, some or all of the hydrogen atoms of these groups may be substituted with a hydroxy group, a carboxy group, a halogen atom, a cyano group, a nitro group, a mercapto group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and some of the carbon atoms of these groups may be substituted with an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate group, or a sulfonate ester bond. 402 and R 403 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring is as defined in the description of formula (1-1) as R 101 and R 102 and , when bonded to each other, can form a ring together with the sulfur atom to which they are bonded, similar to those exemplified above.

[0210] Examples of the cation of the sulfonium salt represented by formula (3-1) include the same as those exemplified as the cation of the sulfonium salt represented by formula (1-1). Examples of the cation of the iodonium salt represented by formula (3-2) include the same as those exemplified as the cation of the iodonium salt represented by formula (1-2).

[0211] Examples of the anion of the onium salt represented by formula (3-1) or (3-2) include, but are not limited to, those shown below. In the following formula, X BI is the same as above. [ka]

[0212] [ka]

[0213]

change

[0214]

change

[0215]

change

[0216]

change

[0217]

change

[0218]

change

[0219]

change

[0220]

change

[0221]

change

[0222]

change

[0223]

change

[0224]

change

[0225]

change

[0226]

change

[0227]

change

[0228]

change

[0229]

change

[0230]

change

[0231]

change

[0232]

change

[0233]

change

[0234] In the resist material of the present invention, the content of the additive acid generator 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 resist material of the present invention can function as a chemically amplified resist material because the base polymer contains the repeating unit f and / or contains an additive acid generator.

[0235] [Organic solvents] The 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 above-mentioned components and the components described below. 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 JP-A-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, and ethylene glycol Examples of the monoethyl ether include ethers such as propylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol mono-tert-butyl ether acetate; and lactones such as γ-butyrolactone.

[0236] In the resist material of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, based on 100 parts by mass of the base polymer. The organic solvent may be used alone or in combination of two or more kinds.

[0237] [Other ingredients] In addition to the above-mentioned components, a quencher other than the salt compound represented by formula (A) (hereinafter, also referred to as other quencher), a surfactant, a dissolution inhibitor, a crosslinking agent, etc. are appropriately combined and blended according to the purpose to form a positive resist material and a negative resist material, and the dissolution rate of the base polymer in the developer is accelerated by a catalytic reaction in the exposed area, so that a positive resist material and a negative resist material with extremely high sensitivity can be obtained. In this case, the dissolution contrast and resolution of the resist film are high, there is exposure margin, and the process adaptability is excellent, and the pattern shape after exposure is good, while the dimensional difference between the coarse and dense regions is small because the acid diffusion can be suppressed in particular, and therefore it is highly practical and can be very effective as a resist material for VLSI.

[0238] Examples of the other quenchers include conventional basic compounds. Examples of conventional basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxy group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of JP-A-2008-111103, particularly amine compounds having a hydroxy group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonic acid ester bond, or compounds having a carbamate group described in JP-A-3790649 are preferred. By adding such basic compounds, for example, the diffusion rate of the acid in the resist film can be further suppressed or the shape can be corrected.

[0239] Other quenchers include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids and carboxylic acids not fluorinated at the α-position, as described in JP-A-2008-158339. Sulfonic acids, imide acids, or methide acids fluorinated at the α-position are necessary for deprotecting the acid labile group of a carboxylic acid ester, but the sulfonic acids or carboxylic acids not fluorinated at the α-position are released by salt exchange with onium salts not fluorinated at the α-position. Sulfonic acids and carboxylic acids not fluorinated at the α-position do not cause a deprotection reaction, and therefore function as quenchers.

[0240] Other examples of the quencher include the polymer-type quencher described in JP 2008-239918 A. This enhances the rectangularity of the resist pattern by orienting on the surface of the resist film. The polymer-type quencher also has the effect of preventing film loss of the pattern and rounding of the pattern top when a protective film for immersion exposure is applied.

[0241] When the resist composition of the present invention contains another quencher, the content thereof is preferably 0 to 5 parts by mass, more preferably 0 to 4 parts by mass, relative to 100 parts by mass of the base polymer. The other quenchers may be used alone or in combination of two or more kinds.

[0242] Examples of the surfactant include those described in paragraphs

[0165] to

[0166] of JP 2008-111103 A. The addition of a surfactant can further improve or control the coatability of the resist material. When the resist material of the present invention contains the surfactant, the 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 kinds.

[0243] When the resist material of the present invention is a positive type, the difference in dissolution rate between the exposed and unexposed areas can be further increased by adding a dissolution inhibitor, and the resolution can be further improved. The dissolution inhibitor includes a compound 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 labile groups at a ratio of 0 to 100 mol % as a whole, or a compound containing a carboxyl group in the molecule, in which the hydrogen atoms of the carboxyl groups are substituted with acid labile groups at an average ratio of 50 to 100 mol % as a whole. Specific examples include bisphenol A, trisphenol, phenolphthalein, cresol novolac, naphthalene carboxylic acid, adamantane carboxylic acid, hydroxyl groups of cholic acid, and compounds in which hydrogen atoms of carboxyl groups are substituted with acid labile groups, and the like, and are described, for example, in paragraphs

[0155] to

[0178] of JP-A-2008-122932.

[0244] When the resist material of the present invention is a positive resist material and contains the dissolution inhibitor, the content thereof is preferably 0 to 50 parts by mass, and more preferably 5 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The dissolution inhibitor may be used alone or in combination of two or more different types.

[0245] On the other hand, when the resist material of the present invention is a negative type, a crosslinking agent can be added to reduce the dissolution rate of the exposed area to obtain a negative pattern. Examples of the crosslinking agent include epoxy compounds, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyloxy groups, which are substituted with at least one group selected from methylol groups, alkoxymethyl groups, and acyloxymethyl groups. These may be used as additives, or may be introduced as pendant groups into the polymer side chain. Compounds containing hydroxyl groups may also be used as crosslinking agents.

[0246] Examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0247] Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are methoxymethylated or a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are acyloxymethylated or a mixture thereof, and the like.

[0248] Examples of the guanamine compound include tetramethylol guanamine, tetramethoxymethyl guanamine, a compound in which 1 to 4 methylol groups of tetramethylol guanamine are methoxymethylated or a mixture thereof, tetramethoxyethyl guanamine, tetraacyloxyguanamine, a compound in which 1 to 4 methylol groups of tetramethylol guanamine are acyloxymethylated or a mixture thereof, and the like.

[0249] Examples of glycoluril compounds include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 methylol groups of tetramethylol glycoluril are methoxymethylated or mixtures thereof, compounds in which 1 to 4 methylol groups of tetramethylol glycoluril are acyloxymethylated or mixtures thereof, etc. Examples of urea compounds include tetramethylol urea, tetramethoxymethyl urea, compounds in which 1 to 4 methylol groups of tetramethylol urea are methoxymethylated or mixtures thereof, tetramethoxyethyl urea, etc.

[0250] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0251] Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0252] Examples of compounds containing an alkenyloxy group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0253] When the resist material of the present invention is a negative resist material and contains a crosslinking agent, the content thereof is preferably 0.1 to 50 parts by mass, and more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The crosslinking agents can be used alone or in combination of two or more kinds.

[0254] The resist material of the present invention may be blended with a water repellency improver to improve the water repellency of the resist film surface. The water repellency improver can be used in immersion lithography without using a topcoat. As the water repellency improver, a polymer containing a fluorinated alkyl group, a polymer containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue of a specific structure, and the like are preferred, and those exemplified in JP-A-2007-297590 and JP-A-2008-111103 are more preferred. The water repellency improver needs to be dissolved in an alkaline developer or an organic solvent developer. The water repellency improver having the specific 1,1,1,3,3,3-hexafluoro-2-propanol residue described above has good solubility in the developer. As a water repellency improver, a polymer containing a repeating unit containing an amino group or an amine salt is highly effective in preventing the evaporation of acid during post-exposure baking (PEB) and preventing poor opening of a hole pattern after development. When the resist composition of the present invention contains a water repellency improver, the content thereof is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, based on 100 parts by mass of the base polymer. The water repellency improver may be used alone or in combination of two or more kinds.

[0255] The resist material of the present invention may also contain acetylene alcohols. Examples of the acetylene alcohols include those described in paragraphs

[0179] to

[0182] of JP 2008-122932 A. When the 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 alone or in combination of two or more.

[0256] [Pattern formation method] When the resist material of the present invention is used in various integrated circuit manufacturing, known lithography techniques can be applied.For example, the pattern forming method includes the steps of forming a resist film on a substrate using the resist material described above, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developer.

[0257] First, the 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 film, 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, doctor coating, etc., so that the coating thickness is 0.01 to 2 μm. This is 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.

[0258] Next, the resist film is exposed to high-energy radiation. Examples of the high-energy radiation include ultraviolet radiation, far ultraviolet radiation, EB, EUV radiation with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, etc. When ultraviolet radiation, far ultraviolet radiation, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, etc. are used as the high-energy radiation, the exposure dose is preferably 1 to 200 mJ / cm2, either directly or using a mask for forming a desired pattern. 2 Approximately, more preferably 10 to 100 mJ / cm 2 When EB is used as the high energy beam, the exposure dose is preferably 0.1 to 100 μC / cm 2 Approximately, more preferably 0.5 to 50 μC / cm 2 The resist material of the present invention is suitable for fine patterning using high-energy radiation such as KrF excimer laser light, ArF excimer laser light, EB, EUV, X-rays, soft X-rays, γ-rays, and synchrotron radiation, and is particularly suitable for fine patterning using EB or EUV.

[0259] After the exposure, PEB may be performed on a hot plate or in an oven, 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.

[0260] After exposure or PEB, the exposed resist film is developed by a conventional method such as a dip method, a puddle method, or a spray method using a developer of an alkaline aqueous solution of 0.1 to 10 mass%, preferably 2 to 5 mass%, such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, or tetrabutylammonium hydroxide for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, to form a desired pattern. In the case of a positive resist material, the part irradiated with light dissolves in the developer, and the part not exposed to light does not dissolve, forming a desired positive pattern on the substrate. In the case of a negative resist material, the opposite is true to the case of a positive resist material, that is, the part irradiated with light becomes insoluble in the developer, and the part not exposed to light dissolves.

[0261] A positive resist material containing a base polymer containing an acid labile group can be used to perform negative development to obtain a negative pattern by organic solvent development. The developer used in this case can be 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, Examples of the organic solvent include methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in combination of two or more.

[0262] At the end of the development, rinsing is performed. As the rinsing liquid, a solvent that is miscible with the developer and does not dissolve the resist film is preferable. As such a solvent, alcohols having 3 to 10 carbon atoms, ether compounds having 8 to 12 carbon atoms, alkanes, alkenes, alkynes, and aromatic solvents having 6 to 12 carbon atoms are preferably used.

[0263] Specific examples of alcohols having 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. , 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, and 1-octanol.

[0264] Examples of the ether compound 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.

[0265] Examples of alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. Examples of alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Examples of alkynes having 6 to 12 carbon atoms include hexine, heptine, octyne, etc.

[0266] Examples of aromatic solvents include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[0267] Rinsing can reduce the occurrence of resist pattern collapse and defects. Rinsing is not always necessary, and not performing rinsing can reduce the amount of solvent used.

[0268] The developed hole pattern or trench pattern can also be shrunk by thermal flow, RELACS technology, or DSA technology. A shrink agent is applied onto the hole pattern, and the shrink agent crosslinks on the surface of the resist film due to the diffusion of an acid catalyst from the resist film during baking, and the shrink agent adheres to the sidewalls of the hole pattern. The baking temperature is preferably 70 to 180°C, more preferably 80 to 170°C, and the baking time is preferably 10 to 300 seconds, and excess shrink agent is removed to reduce the hole pattern. EXAMPLES

[0269] 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.

[0270] The structures of quenchers Q-1 to Q-40 used in the resist material are shown below. [ka]

[0271] [ka]

[0272] [ka]

[0273] [ka]

[0274] [ka]

[0275] [Synthesis Example] Synthesis of base polymers (P-1 to P-4) Each monomer was combined and copolymerized in THF, which was a solvent, crystallized in methanol, and then repeatedly washed with hexane. The resulting polymers were isolated and dried to obtain the base polymers (P-1 to P-4) with the compositions shown below. 1 Mw and Mw / Mn were confirmed by H-NMR and GPC (solvent: THF, standard: polystyrene). [ka]

[0276] [Examples 1 to 48, Comparative Examples 1 to 3] (1) Preparation of resist material Resist materials were prepared by filtering solutions prepared by dissolving each component according to the composition shown in Tables 1 to 3 in a solvent containing 100 ppm of Omnova's Polyfox PF-636 as a surfactant through a 0.2 μm filter. The resist materials of Examples 1 to 47 and Comparative Examples 1 and 2 are positive-type, and the resist materials of Example 48 and Comparative Example 3 are negative-type.

[0277] In Tables 1 to 3, the components are as follows. Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) DAA (Diacetone Alcohol)

[0278] Acid generator: PAG-1~PAG-5 [ka]

[0279] Blend Quencher: bQ-1~bQ-3 [ka]

[0280] Comparison quenchers: cQ-1, cQ-2 [ka]

[0281] (2) EUV lithography evaluation Each resist material shown in Tables 1 to 3 was spin-coated on a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. was formed to a thickness of 20 nm, and the resist film was pre-baked for 60 seconds at 105°C using a hot plate to produce a resist film with a thickness of 50 nm. This was exposed using an EUV scanner NXE3300 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, quadruple pole illumination, a hole pattern mask with a pitch of 46 nm on the wafer and a +20% bias), and PEB was performed for 60 seconds on a hot plate at the temperatures shown in Tables 1 to 3, and development was performed for 30 seconds with a 2.38% by mass TMAH aqueous solution to form hole patterns with a size of 23 nm in Examples 1 to 47 and Comparative Examples 1 and 2, and dot patterns with a size of 23 nm in Example 48 and Comparative Example 3. Using a length measuring SEM (CG5000) manufactured by Hitachi High-Technologies Corporation, the exposure dose when a hole or dot dimension of 23 nm was formed was measured and used as the sensitivity. The dimensions of 50 holes or dots at this time were also measured, and three times (3σ) the standard deviation (σ) calculated from the results was used as the dimensional variation (CDU). The results are shown in Tables 1 to 3.

[0282] [Table 1]

[0283] [Table 2]

[0284] [Table 3]

[0285] The results shown in Tables 1 to 3 demonstrate that the resist material of the present invention, which contains the salt compound represented by formula (A), has high sensitivity and small CDU.

Claims

1. A resist material comprising a base polymer and a quencher comprising a salt compound represented by the following formula (A): 【Chemistry 1】 (In the formula, m 1 is 1 or 2. 2 is 1. n is an integer from 1 to 3. j is an integer from 1 to 3. k is 1 or 2. X BI is an iodine atom or a bromine atom. R ah is a (j+1)-valent aliphatic hydrocarbon group having 1 to 20 carbon atoms, which may contain an aryl group having 6 to 12 carbon atoms. X 1 is a single bond, an ether bond, an ester bond, an amide bond, a carbonyl group or a carbonate group. R 1 (m) is a C1-20 alkyl group which may contain an ether bond. 1 +1)valent hydrocarbon group. R 2 is a single bond or a carbon number of 1 to 20 (m 2 +1)valent hydrocarbon group. R 3 is a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and the hydrocarbyl group may contain a halogen atom. When n is 1, two R 3 may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and in this case, the ring may contain a double bond, an oxygen atom, a sulfur atom, or a nitrogen atom. 3 and R 1 may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and in this case, the ring may contain a double bond, an oxygen atom, a sulfur atom or a nitrogen atom. A k- is a carboxylate anion, a sulfonimide anion not containing a fluorine atom, a sulfonamide anion, or a halide ion.

2. A resist material according to claim 1, wherein the cation of the compound represented by formula (A) is represented by any of the following formulas. 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】

3. 3. The resist material according to claim 1, wherein the carboxylate anion is represented by the following formula (Aa-1) or (Aa-2), the fluorine-free sulfonimide anion is represented by the following formula (Ab), and the sulfonamide anion is represented by the following formula (Ac): 【Chemistry 6】 (In the formula, R a1 is a hydrogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. R a2 is a single bond or a hydrocarbylene group having 1 to 30 carbon atoms which may contain a heteroatom. R b1 and R b2 are each independently a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a hydroxy group, an ether bond, or an ester bond. b1 and R b2 may be bonded to each other to form a ring. R c1 R is a fluorine atom, a hydrocarbyl group having 1 to 10 carbon atoms, or a fluorinated hydrocarbyl group having 1 to 10 carbon atoms, and may contain a hydroxy group, an ether bond, or an ester bond. c2 is a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms, which may contain a hydroxy group, an ether bond, or an ester bond. c1 and R c2 may be bonded to each other to form a ring together with the atoms to which they are attached.

4. 4. The resist material according to claim 1, further comprising an acid generator that generates a sulfonic acid, an imide acid or a methide acid.

5. The resist material according to any one of claims 1 to 4, further comprising an organic solvent.

6. The resist material according to any one of claims 1 to 5, wherein the base polymer contains a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2): 【Chemistry 7】 (In the formula, R A are each independently a hydrogen atom or a methyl group. R 11 and R 12 are each independently an acid labile group. Y 1 is a linking group having 1 to 12 carbon atoms and containing at least one selected from a single bond, a phenylene group, a naphthylene group, an ester bond, and a lactone ring. Y 2 is a single bond or an ester bond.

7. The resist material of claim 6 which is a chemically amplified positive resist material.

8. 6. The resist material according to claim 1, wherein the base polymer does not contain an acid labile group.

9. 9. The resist material of claim 8 which is a chemically amplified negative resist material.

10. The resist material according to any one of claims 1 to 9, further comprising a surfactant.

11. The resist material according to any one of claims 1 to 10, wherein the base polymer further comprises at least one repeating unit selected from the group consisting of repeating units represented by the following formulas (f1) to (f3): 【Chemistry 8】 (In the formula, R A are each independently a hydrogen atom or a methyl group. Z 1 represents 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-Z 11 -, -C(=O)-O-Z 11 - or -C(=O)-NH-Z 11 - is. 11 represents 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 hydroxy group. Z 2 is a single bond, -Z 21 -C(=O)-O-, -Z 21 -O- or -Z 21 -O-C(=O)-. Z 21 is a saturated hydrocarbylene group having 1 to 12 carbon atoms, which may contain a carbonyl group, an ester bond or an ether bond. Z 3 represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, -O-Z 31 -, -C(=O)-O-Z 31 - or -C(=O)-NH-Z 31 - is. 31 represents an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. R 21 ~R 28 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 23 and R 24 Or R 26 and R 27 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. R HF is a hydrogen atom or a trifluoromethyl group. M - is a non-nucleophilic counterion.)

12. A pattern forming method comprising the steps of: forming a resist film on a substrate using the resist material according to any one of claims 1 to 11; exposing the resist film to high-energy radiation; and developing the exposed resist film using a developer.

13. 13. The method for forming a pattern according to claim 12, wherein the high-energy radiation is an ArF excimer laser beam having a wavelength of 193 nm or a KrF excimer laser beam having a wavelength of 248 nm.

14. 13. The pattern forming method according to claim 12, wherein the high energy beam is an electron beam or extreme ultraviolet light having a wavelength of 3 to 15 nm.

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