Resist material and pattern forming method

Abstract

To provide a resist material which has high sensitivity and hardly causes nanobridges, pattern collapse and residues even when being positive or negative, and to provide a pattern forming method using the same.SOLUTION: The resist material contains: an ammonium salt- and fluorine atom-containing polymer which contain a repeating unit AU having an ammonium salt structure that contains a carboxylic acid anion containing fluorine atoms and containing neither an iodine atom nor a bromine atom, a sulfonamide anion containing fluorine atoms and containing neither an iodine atom nor a bromine atom, a phenoxide anion containing fluorine atoms and containing neither an iodine atom nor a bromine atom, or an enolate anion of a β-diketone containing fluorine atoms and containing neither an iodine atom nor a bromine atom, and which contains at least one selected from a repeating unit FU-1 having a trifluoromethyl alcohol group optionally substituted with an acid-labile group and a repeating unit FU-2 having a fluorinated hydrocarbyl group; and a base polymer.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 mass production of 10nm node devices using double patterning with ArF immersion lithography, and mass production of 7nm node devices using double patterning is just beginning for the next generation. Extreme ultraviolet (EUV) lithography is being considered as a candidate for the next-generation 5nm node.

[0003] EUV lithography has problems such as the transfer of defects contained in the mask blanks, which are made up of a total of 80 layers of Mo and Si, and the problem of particles in the exposure machine adhering to the mask because there is no high-strength pellicle that has little loss of light intensity and is not prone to damage during exposure, making it an urgent task to reduce defects.In addition, EUV lithography forms patterns with dimensions less than half those formed by conventional ArF immersion lithography, which increases the probability of defects occurring and necessitates more advanced defect control.

[0004] Here, in resist materials for ArF immersion lithography, an additive that is a fluorine atom-containing polymer that orients on the surface of the resist film to improve water repellency has been proposed (Patent Document 1). This additive has 1,1,1,3,3,3-hexafluoro-2-propanol (HFA) groups, which improves the solubility of the resist film surface in an alkaline developer and reduces bridge defects that occur on the resist surface.

[0005] Furthermore, it has been shown that the addition of a polymer containing a repeating unit having an HFA group and a rigid repeating unit having an aromatic group can reduce outgassing from the resist film during EUV exposure (Patent Documents 2 and 3). It has been shown that modification of the resist film surface can reduce pattern defects and suppress outgassing.

[0006] Materials containing amino groups or ammonium salts of fluorosulfonic acid in fluorine atom-containing polymers that orient on the surface of the resist film to improve water repellency have been proposed (Patent Documents 4 and 5). This suppresses the diffusion of acid on the resist film surface, improving the rectangularity of the resist pattern after development. However, since the absorption of EUV is not very high, the sensitization effect of this is limited. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2007-297590 A [Patent Document 2] JP 2014-67014 A [Patent Document 3] JP 2014-67012 A [Patent Document 4] JP 2009-31767 A [Patent Document 5] JP 2008-239918 A Summary of the Invention [Problem to be solved by the invention]

[0008] There is a need for the development of acid-catalyzed chemically amplified resist materials that can reduce nanobridging and pattern collapse in line patterns, leave no residue in space areas, and improve sensitivity.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a resist material which is highly sensitive and unlikely to cause nanobridges, pattern collapse, or residues, whether positive or negative, and a pattern formation method using the same. [Means for solving the problem]

[0010] As a result of intensive research into achieving the above-mentioned object, the present inventors have found that by adding a polymer (hereinafter also referred to as an ammonium salt- and fluorine-atom-containing polymer) containing a repeating unit having an ammonium salt structure containing a carboxylate anion that contains fluorine atoms but not iodine atoms or bromine atoms, a sulfonamide anion that contains fluorine atoms but not iodine atoms or bromine atoms, a phenoxide anion that contains fluorine atoms but not iodine atoms or bromine atoms, or an enolate anion of a β-diketone that contains fluorine atoms but not iodine atoms or bromine atoms, and at least one selected from a repeating unit having a trifluoromethyl alcohol group optionally substituted with an acid labile group and a repeating unit having a fluorinated hydrocarbyl group, it is possible to obtain a resist material which prevents the occurrence of nanobridges and pattern collapse, has a wide process margin, is excellent in line pattern edge roughness (LWR) and hole pattern dimensional uniformity (CDU), and leaves no residue in space portions, thereby completing the present invention.

[0011] That is, the present invention provides the following resist material and pattern forming method. 1. A resist material comprising a repeating unit AU having an ammonium salt structure containing a carboxylate anion that contains fluorine atoms but not iodine atoms or bromine atoms, a sulfonamide anion that contains fluorine atoms but not iodine atoms or bromine atoms, a phenoxide anion that contains fluorine atoms but not iodine atoms or bromine atoms, or an enolate anion of a β-diketone that contains fluorine atoms but not iodine atoms or bromine atoms, and at least one selected from a repeating unit FU-1 having a trifluoromethyl alcohol group optionally substituted with an acid labile group and a repeating unit FU-2 having a fluorinated hydrocarbyl group, and a base polymer. 2. The resist material of 1, wherein the repeating unit AU is represented by the following formula (AU), the repeating unit FU-1 is represented by the following formula (FU-1), and the repeating unit FU-2 is represented by the following formula (FU-2). [ka] (In the formula, n 1 is 1 or 2. 2 is 0 <n 2 / n 1 A positive number that satisfies ≦1. 3 is 1 or 2. R A are each independently a hydrogen atom or a methyl group. X 1A is a single bond, a phenylene group, an ester bond or an amide bond. X 1B is a single bond or a group having 1 to 20 carbon atoms (n 1 The hydrocarbon group may contain an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxy group, or a carboxy group. X 2A is a single bond, a phenylene group, -O-, -C(=O)-O-, or -C(=O)-NH-. X 2B is a group of 1 to 12 carbon atoms (n 3 +1)-valent saturated hydrocarbon group or (n3 It is a monovalent aromatic hydrocarbon group which may contain a fluorine atom, a hydroxyl group, an ester bond or an ether bond. X 3 is a single bond, a phenylene group, -O-, -C(=O)-OX 31 -X 32 - or -C(=O)-NH-X 31 -X 32 -It is. X 31 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. 32 is a single bond, an ester bond, an ether bond or a sulfonamide bond. R 1 , R 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. 1 and R 2 and R 1 and X 1B may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and the ring may contain an oxygen atom, a sulfur atom, a nitrogen atom or a double bond. R 4 represents a single bond, an ester bond, or a saturated hydrocarbylene group having 1 to 12 carbon atoms, some or all of the hydrogen atoms of the saturated hydrocarbylene group may be substituted with fluorine atoms, and some of the carbon atoms of the saturated hydrocarbylene group may be substituted with ester bonds or ether bonds. R 5 R is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a difluoromethyl group. 5 and R 6 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the ring may contain an ether bond, a fluorine atom, or a trifluoromethyl group. R 6 is a hydrogen atom or an acid labile group. R 7represents a hydrocarbyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, some of the carbon atoms of which may be substituted with an ester bond or an ether bond. X - is a carboxylate anion containing fluorine atoms but not containing iodine or bromine atoms, a sulfonamide anion containing fluorine atoms but not containing iodine or bromine atoms, a phenoxide anion containing fluorine atoms but not containing iodine or bromine atoms, or an enolate anion of a β-diketone containing fluorine atoms but not containing iodine or bromine atoms. 3. The resist material according to 1 or 2, comprising the ammonium salt and the fluorine atom-containing polymer in an amount of 0.001 to 20 parts by mass per 100 parts by mass of a base polymer. 4. The resist material according to any one of 1 to 3, further comprising an acid generator that generates a sulfonic acid, an imide acid or a methide acid. 5. A resist material according to any one of 1 to 4, further comprising an organic solvent. 6. The resist material of any one of 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): [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. R 13 is a fluorine atom, a trifluoromethyl group, a saturated hydrocarbyl group having 1 to 5 carbon atoms, or a saturated hydrocarbyloxy group having 1 to 5 carbon atoms. Y 1 is a divalent 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. a is an integer from 0 to 4. 7. The resist material of 6, which is a chemically amplified positive resist material. 8. The resist material of any one of 1 to 5, wherein the base polymer does not contain an acid labile group. 9. The resist material of 8, which is a chemically amplified negative resist material. 10. The resist material of any one of 1 to 9, wherein the base polymer contains a repeating unit represented by any one of 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 or an ester bond. Z 3 is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -OC(=O)-. Z 31 represents a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene 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, an iodine atom, or a bromine atom. Z 4 is a methylene group, a 2,2,2-trifluoro-1,1-ethanediyl group, or a carbonyl group. Z 5 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -OZ 51-, -C(=O)-OZ 51 - or -C(=O)-NH-Z 51 -It is. 51 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 and R 26 and R 27 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached. M - is a non-nucleophilic counterion. 11. A resist material according to any one of 1 to 10, further comprising a surfactant. 12. A pattern forming method comprising the steps of forming a resist film on a substrate using a 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. The pattern formation method according to claim 12, 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. 14. The pattern formation method according to claim 12, wherein the high energy beam is an electron beam (EB) or EUV having a wavelength of 3 to 15 nm. Effect of the Invention

[0012] The ammonium salt and the fluorine atom-containing polymer are polymer-type quenchers that are highly soluble in an alkaline developer. The polymer contains not only a repeating unit having an ammonium salt structure with a fluorine atom, but also a repeating unit having a fluorine atom, so that after a resist film is formed using a resist material containing the polymer and a base polymer, the polymer is highly oriented on the surface. This allows fluorine atoms to be present in a high density near the surface of the resist film, increasing the absorption of exposure light by the fluorine atoms, and exerting a sensitizing effect, while at the same time controlling acid diffusion near the surface layer of the resist film and preventing the evaporation of acid from the surface layer of the resist film, thereby increasing the rectangularity of the resist pattern after development, improving the LWR of the line pattern and the CDU of the hole pattern when observed from above. Furthermore, the solubility of the resist film surface in an alkaline developer is improved, reducing bridge defects and pattern collapse after pattern formation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [Resist material] The resist material of the present invention contains an ammonium salt and a fluorine atom-containing polymer, and a base polymer.

[0014] [Ammonium salt and fluorine atom-containing polymer] The ammonium salt and fluorine atom-containing polymer comprises a repeating unit AU having an ammonium salt structure containing a carboxylate anion that contains fluorine atoms but does not contain iodine atoms or bromine atoms, a sulfonamide anion that contains fluorine atoms but does not contain iodine atoms or bromine atoms, a phenoxide anion that contains fluorine atoms but does not contain iodine atoms or bromine atoms, or an enolate anion of a β-diketone that contains fluorine atoms but does not contain iodine atoms or bromine atoms, and at least one selected from a repeating unit FU-1 having a trifluoromethyl alcohol group optionally substituted with an acid labile group, and a repeating unit FU-2 having a fluorinated hydrocarbyl group.

[0015] The repeating unit AU preferably has the above ammonium salt structure as a pendant group, and is particularly preferably represented by the following formula (AU). [ka]

[0016] In formula (AU), n 1 is 1 or 2. 2 is 0 <n 2 / n 1 It is a positive number that satisfies ≦1.

[0017] In formula (AU), R A are each independently a hydrogen atom or a methyl group.

[0018] In formula (AU), X 1A X is a single bond, a phenylene group, an ester bond or an amide bond. 1B is a single bond or a group having 1 to 20 carbon atoms (n 1 The hydrocarbon group may contain an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxy group, or a carboxy group.

[0019] X 1B (n 1 The hydrocarbon group having a valence of +1 is selected from aliphatic hydrocarbons having 1 to 20 carbon atoms or aromatic hydrocarbons having 6 to 20 carbon atoms (n 1+1) hydrogen atoms are eliminated, and may be linear, branched, or cyclic. Specific examples include saturated hydrocarbons having 1 to 20 carbon atoms, such as methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, methylcyclopentane, ethylcyclopentane, methylcyclohexane, ethylcyclohexane, 1-propylcyclohexane, isopropylcyclohexane, norbornane, adamantane, methylnorbornane, ethylnorbornane, methyladamantane, ethyladamantane, and tetrahydrodicyclopentadiene. 1 +1) hydrogen atoms are eliminated from aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, 1-propylbenzene, isopropylbenzene, and naphthalene. 1 +1) hydrogen atoms; and groups obtained by combining these.

[0020] In formula (AU), R 1 , R 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. 1 and R 2 and R 1 and X 1B may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and the ring may contain an oxygen atom, a sulfur atom, a nitrogen atom, or a double bond. In this case, the ring is preferably a ring having 3 to 12 carbon atoms.

[0021] R 1 , R 2 and R 3The alkyl group having 1 to 12 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include 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-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, and an n-dodecyl group. 1 , R 2 and R 3 Examples of the alkenyl group having 2 to 12 carbon atoms represented by the formula (I) include a vinyl group, a 1-propenyl group, a 2-propenyl group, a butenyl group, and a hexenyl group. 1 , R 2 and R 3 Examples of the aryl group having 6 to 12 carbon atoms represented by the formula (I) include a phenyl group, a tolyl group, a xylyl group, a 1-naphthyl group, and a 2-naphthyl group. 1 , R 2 and R 3 Examples of the aralkyl group having 7 to 12 carbon atoms represented by the following formula include a benzyl group.

[0022] Examples of the cation of the monomer that gives the repeating unit AU include, but are not limited to, those shown below. A is the same as above. [ka]

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] [ka]

[0027] [ka]

[0028] In formula (AU), X - is a carboxylate anion containing fluorine atoms but not containing iodine or bromine atoms, a sulfonamide anion containing fluorine atoms but not containing iodine or bromine atoms, a phenoxide anion containing fluorine atoms but not containing iodine or bromine atoms, or an enolate anion of a β-diketone containing fluorine atoms but not containing iodine or bromine atoms.

[0029] The carboxylate anion is preferably one represented by the following formula (an-1). The sulfonamide anion is preferably one represented by the following formula (an-2). The phenoxide anion is preferably one represented by the following formula (an-3). The β-diketone enolate anion is preferably one represented by the following formula (an-4). [ka]

[0030] In formula (an-1), R a1 represents a fluorine atom, a fluorinated hydrocarbyl group having 1 to 30 carbon atoms, or a fluorinated heteroaryl group having 2 to 30 carbon atoms, and the fluorinated hydrocarbyl group and the fluorinated heteroaryl group may contain a hydroxy group, an amino group, a nitro group, an ether bond, an ester bond, or a thiol group.

[0031] R a1 The fluorinated hydrocarbyl group represented by the formula (1A') below is a group in which some or all of the hydrogen atoms of a hydrocarbyl group are substituted with fluorine atoms, and may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples of the hydrocarbyl group include R 111Examples of the hydrocarbyl group represented by the formula R a1 The fluorinated heteroaryl group represented by the following formula is a heteroaryl group in which some or all of the hydrogen atoms have been substituted with fluorine atoms. Specific examples of the heteroaryl group include a pyridyl group and a methylpyridyl group.

[0032] In formula (an-2), R a2 R is a fluorine atom or a fluorinated hydrocarbyl group having 1 to 10 carbon atoms, and the fluorinated hydrocarbyl group may contain a hydroxy group, an ether bond, an ester bond, an amide bond or a thiol group. a2 The fluorinated hydrocarbyl group represented by the formula (1A') below is a group in which some or all of the hydrogen atoms of a hydrocarbyl group are substituted with fluorine atoms, and may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples of the hydrocarbyl group include R 111 Among the examples of hydrocarbyl groups represented by the following formula, those having 1 to 10 carbon atoms can be mentioned.

[0033] In formula (an-2), R a3 R is a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms, and the hydrocarbyl group may contain a hydroxy group, an ether bond, or an ester bond. a3 The hydrocarbyl group represented by the formula (1) 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 hydrocarbyl group having 2 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 6 to 10 carbon atoms, and groups obtained by combining these groups.

[0034] In formula (an-3), m 1 and m 2 is 1≦m 1 ≦5, 0≦m 2 ≦3 and ≦1 m 1 +m 2 It is an integer satisfying the condition ≦5.

[0035] In formula (an-3), R a4 is a fluorine atom, a trifluoromethyl group, or a 1,1,1,3,3,3-hexafluoro-2-propanol group.

[0036] In formula (an-3), R a5 is a hydroxy group, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbylcarbonyl group having 2 to 7 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbylcarbonyloxy group having 2 to 7 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxycarbonyl group having 2 to 7 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms which may be substituted with a halogen atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, -N(R a5A )-C(=O)-R a5B Or -N(R a5A )-C(=O)-OR a5B R a5A is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. a5B is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms.

[0037] R a5 , R a5A and R a5BThe saturated hydrocarbyl group having 1 to 6 carbon atoms represented by the formula (I) may be linear, branched or cyclic, and specific examples thereof include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl and n-hexyl groups; and cycloalkyl groups having 3 to 6 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl groups. Examples of the saturated hydrocarbyl moiety of the saturated hydrocarbyloxy group having 1 to 6 carbon atoms, the saturated hydrocarbylcarbonyl group having 2 to 7 carbon atoms, the saturated hydrocarbylcarbonyloxy group having 2 to 7 carbon atoms and the saturated hydrocarbyloxycarbonyl group having 2 to 7 carbon atoms include the same as the specific examples of the saturated hydrocarbyl group described above, and examples of the saturated hydrocarbyl moiety of the saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms include those having 1 to 4 carbon atoms among the specific examples of the saturated hydrocarbyl groups described above.

[0038] R a5B The unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include alkenyl groups having 2 to 8 carbon atoms, such as a vinyl group, a 1-propenyl group, a 2-propenyl group, a butenyl group, and a hexenyl group; and cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 8 carbon atoms, such as a cyclohexenyl group.

[0039] In formula (an-4), R a6 R is a fluorinated hydrocarbyl group having 1 to 10 carbon atoms, a hydrocarbyl group having 1 to 10 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms. a7 is a fluorinated hydrocarbyl group having 1 to 10 carbon atoms.

[0040] R a6 and R a7 The fluorinated hydrocarbyl group represented by the formula (1A') below is a group in which some or all of the hydrogen atoms of a hydrocarbyl group are substituted with fluorine atoms, and may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples of the hydrocarbyl group include R 111Among the examples of the hydrocarbyl group represented by the following formula, there can be mentioned those having a carbon number of 1 to 10. As the hydrocarbyl group, a saturated hydrocarbyl group having a carbon number of 1 to 10 or an aryl group having a carbon number of 6 to 10 is preferable.

[0041] R a6 The hydrocarbyl group having 1 to 10 carbon atoms represented by the formula (1A') may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include R 111 Among the examples of the hydrocarbyl group represented by the following formula, there can be mentioned those having a carbon number of 1 to 10. As the hydrocarbyl group, a saturated hydrocarbyl group having a carbon number of 1 to 10 or an aryl group having a carbon number of 6 to 10 is preferable.

[0042] R a6 Examples of the heteroaryl group having 2 to 10 carbon atoms represented by the following formula include a thienyl group and a furyl group.

[0043] Examples of the carboxylate anion containing a fluorine atom and not containing an iodine atom or a bromine atom include, but are not limited to, the following anions. [ka]

[0044] [ka]

[0045] [ka]

[0046] [ka]

[0047] Examples of the sulfonamide anion containing a fluorine atom and not containing an iodine atom or a bromine atom include, but are not limited to, those shown below. [ka]

[0048] [ka]

[0049] [ka]

[0050] [ka]

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] Examples of the phenoxide anion containing a fluorine atom and not containing an iodine atom or a bromine atom include, but are not limited to, those shown below. [ka]

[0057] [ka]

[0058] Examples of the enolate anion of the β-diketone containing a fluorine atom but not containing an iodine atom or a bromine atom include, but are not limited to, those shown below. [ka]

[0059] The monomer that gives the repeating unit AU is a polymerizable ammonium salt type monomer. The ammonium salt type monomer can be obtained by a neutralization reaction between a monomer that is an amine compound having a structure in which one hydrogen atom bonded to the nitrogen atom of the cation of the repeating unit is eliminated, and a carboxylic acid that contains fluorine atoms but does not contain iodine atoms or bromine atoms, a sulfonamide that contains fluorine atoms but does not contain iodine atoms or bromine atoms, a phenol compound that contains fluorine atoms but does not contain iodine atoms or bromine atoms, or a β-diketone that contains fluorine atoms but does not contain iodine atoms or bromine atoms.

[0060] The repeating unit AU is formed by carrying out a polymerization reaction using the ammonium salt type monomer. Alternatively, the repeating unit AU may be formed by synthesizing a polymer by carrying out a polymerization reaction using a monomer which is the amine compound, and then adding a carboxylic acid which contains fluorine atoms but does not contain iodine atoms or bromine atoms, a sulfonamide which contains fluorine atoms but does not contain iodine atoms or bromine atoms, a phenol compound which contains fluorine atoms but does not contain iodine atoms or bromine atoms, or a β-diketone which contains fluorine atoms but does not contain iodine atoms or bromine atoms to the obtained reaction solution or a solution containing the purified polymer, and carrying out a neutralization reaction.

[0061] In this case, in order to obtain the effects of the present invention, the neutralization reaction is ideally carried out in such amounts that the substance ratio (molar ratio) between the amino group of the amine compound and the carboxylic acid that contains fluorine atoms but does not contain iodine atoms and bromine atoms, the sulfonamide that contains fluorine atoms but does not contain iodine atoms and bromine atoms, the phenol compound that contains fluorine atoms but does not contain iodine atoms and bromine atoms, or the β-diketone that contains fluorine atoms but does not contain iodine atoms and bromine atoms is 1:1. However, the carboxylic acid that contains fluorine atoms but does not contain iodine atoms and bromine atoms, the sulfonamide that contains fluorine atoms but does not contain iodine atoms and bromine atoms, the phenol compound that contains fluorine atoms but does not contain iodine atoms and bromine atoms, or the β-diketone that contains fluorine atoms but does not contain iodine atoms and bromine atoms may be in excess or in excess of the amino group.

[0062] The repeating units FU-1 and FU-2 are preferably those represented by the following formulae (FU-1) and (FU-2), respectively. [ka]

[0063] In formula (FU-1), n 3 is 1 or 2.

[0064] In formulas (FU-1) and (FU-2), R A are each independently a hydrogen atom or a methyl group.

[0065] In formula (FU-1), X 2A is a single bond, a phenylene group, -O-, -C(=O)-O-, or -C(=O)-NH-. 2B is a group of 1 to 12 carbon atoms (n 3 +1)-valent saturated hydrocarbon group or (n 3 It is a monovalent aromatic hydrocarbon group which may contain a fluorine atom, a hydroxyl group, an ester bond or an ether bond.

[0066] X 2B (n 3The saturated hydrocarbon group having a valence of +1 may be linear, branched, or cyclic, and specific examples thereof include saturated hydrocarbons such as methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, methylcyclopentane, ethylcyclopentane, methylcyclohexane, ethylcyclohexane, 1-propylcyclohexane, isopropylcyclohexane, norbornane, adamantane, methylnorbornane, ethylnorbornane, methyladamantane, ethyladamantane, and tetrahydrodicyclopentadiene. 3 +1) hydrogen atoms are eliminated. 2B (n 3 The aromatic hydrocarbon group having a valence of +1 may be selected from aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, 1-propylbenzene, isopropylbenzene, and naphthalene. 3 +1) hydrogen atoms are eliminated.

[0067] In formula (FU-2), X 3 is a single bond, a phenylene group, -O-, -C(=O)-OX 31 -X 32 - or -C(=O)-NH-X 31 -X 32 -It is. X 31 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. 32 is a single bond, an ester bond, an ether bond, or a sulfonamide bond. Examples of the alkanediyl group having 1 to 4 carbon atoms 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, and a 1,1-dimethylethane-1,2-diyl group.

[0068] In formula (FU-1), R 4is a single bond, an ester bond, or a saturated hydrocarbylene group having 1 to 12 carbon atoms, some or all of the hydrogen atoms of the saturated hydrocarbylene group may be substituted with fluorine atoms, and some of the carbon atoms of the saturated hydrocarbylene group may be substituted with ester bonds or ether bonds. The saturated hydrocarbylene group may be linear, branched, or cyclic.

[0069] In formula (FU-1), R 5 R is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a difluoromethyl group. 4 and R 5 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the ring may contain an ether bond, a fluorine atom, or a trifluoromethyl group.

[0070] In formula (FU-1), R 6 is a hydrogen atom or an acid labile group. Specific examples of the acid labile group will be described later.

[0071] In formula (FU-2), R 7 is a hydrocarbyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, and some of the carbon atoms may be substituted with an ester bond or an ether bond. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in the formulae (1-1) and (1-2) described below. 101 ~R 105 Among these, saturated hydrocarbyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, etc. are preferred.

[0072] Examples of monomers that provide the repeating unit FU-1 include, but are not limited to, those shown below. A and R 6 is the same as above. [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] Examples of monomers that provide the repeating unit FU-2 include, but are not limited to, those shown below. A is the same as above. [ka]

[0079] [ka]

[0080] [ka]

[0081] [ka]

[0082] [ka]

[0083] [Chem.]

[0084] [Chem.]

[0085] [Chem.] By including at least one selected from the repeating units FU-1 and FU-2, the ammonium salt and the fluorine atom-containing polymer enhance the efficiency of orientation on the resist film surface after the formation of the resist film.

[0086] In addition to the repeating units AU, FU-1, and FU-2, the ammonium salt and the fluorine atom-containing polymer may contain a repeating unit that functions as an acid generator. Examples of such repeating units include repeating units represented by any of the following formulas (f1) to (f3).

[0087] The content ratios of the repeating units AU, FU-1, and FU-2 are preferably 0 < AU < 1.0, 0 ≤ (FU-1) < 1.0, 0 ≤ (FU-2) < 1.0, and 0 < (FU-1) + (FU-2) < 1.0, more preferably 0.001 ≤ AU ≤ 0.7, 0 ≤ (FU-1) ≤ 0.95, 0 ≤ (FU-2) ≤ 0.95, and 0.1 ≤ (FU-1) + (FU-2) ≤ 0.99, and even more preferably 0.01 ≤ AU ≤ 0.5, 0 ≤ (FU-1) ≤ 0.8, 0 ≤ (FU-2) ≤ 0.8, and 0.2 ≤ (FU-1) + (FU-2) ≤ 0.98. Also, the ammonium salt and the fluorine atom-containing polymer may contain other repeating units as long as the effects of the present invention are not impaired, but it is preferable that they do not contain other repeating units (i.e., AU + (FU-1) + (FU-2) = 1).

[0088] The weight average molecular weight (Mw) of the ammonium salt and the fluorine atom-containing polymer is preferably 1,000 to 1,000,000, more preferably 2,000 to 100,000. The molecular weight distribution (Mw / Mn) is preferably 1.0 to 3.0. Mw and Mn are values ​​measured in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0089] The ammonium salt and the fluorine atom-containing polymer are oriented on the surface of the resist film, thereby improving the solubility of the resist film surface in an alkaline developer, thereby making it possible to prevent bridge defects and pattern collapse.

[0090] In the resist material of the present invention, the content of the ammonium salt and fluorine atom-containing polymer is preferably 0.001 to 20 parts by mass, and more preferably 0.01 to 10 parts by mass, per 100 parts by mass of the base polymer described below, from the viewpoints of sensitivity and acid diffusion suppression effect.

[0091] [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]

[0092] 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 the repeating unit a1 and the repeating unit a2, R 11 and R 12 may be the same or different.13 Y is a fluorine atom, a trifluoromethyl group, a saturated hydrocarbyl group having 1 to 5 carbon atoms, or a saturated hydrocarbyloxy group having 1 to 5 carbon atoms. 1 Y is a divalent 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. a is an integer of 0 to 4.

[0093] 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]

[0094] 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]

[0095] R in formula (FU-1) 6 R in formula (a1) is an acid labile group represented by the formula 11 and R in formula (a2) 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.

[0096] 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.)

[0097] 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.

[0098] In formula (AL-1), b is an integer of 0 to 10, and an integer of 1 to 5 is preferable.

[0099] In formula (AL-2), R L3 and R L4 are 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.

[0100] 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 L7Any 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.

[0101] 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]

[0102] The base polymer may contain a repeating unit c containing a hydroxy group other than a phenolic hydroxy group, a lactone ring, a sultone ring, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonyl group, a sulfonyl 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]

[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] [ka]

[0111] 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]

[0112] The base polymer may include repeat units e derived from styrene, vinyl naphthalene, vinyl anthracene, vinyl pyrene, methylene indane, vinyl pyridine, or vinyl carbazole.

[0113] 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]

[0114] In formulas (f1) to (f3), R A are each independently a hydrogen atom or a methyl group. 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 Z 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 or an ester bond. 3 is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -OC(=O)-. Z 31 Z is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom. 4 is a methylene group, a 2,2,2-trifluoro-1,1-ethanediyl group, or a carbonyl group. 5is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -OZ 51 -, -C(=O)-OZ 51 - or -C(=O)-NH-Z 51 -It is. 51 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.

[0115] 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 above are the same as those exemplified in the explanation of R. 23 and R 24 and R 26 and R 27 and 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 the sulfur atom to which they are bonded to form a ring, the same as those exemplified above.

[0116] 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.

[0117] Other 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]

[0118] In formula (f1-1), R 31 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 in formula (1A'). 111 Examples of the hydrocarbyl group represented by the formula (I) include the same as those described below.

[0119] In formula (f1-2), R 32is 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 moiety of the hydrocarbyl group and the hydrocarbylcarbonyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (1A'). 111 Examples of the hydrocarbyl group represented by the formula (I) include the same as those described below.

[0120] 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]

[0121] 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.

[0122] 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]

[0123] [ka]

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127] [ka]

[0128] [ka]

[0129] [ka]

[0130] [ka]

[0131] [ka]

[0132] [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] By bonding an acid generator to the polymer main chain, acid diffusion can be reduced, and a decrease in resolution due to blurring of acid diffusion can be prevented. Further, the LWR and CDU are improved by the uniform dispersion of the acid generator. When using a base polymer containing the repeating unit f (that is, a polymer-bound acid generator), the blending of the additive acid generator described later can be omitted.

[0136] The base polymer for the positive resist material essentially requires the 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, and 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.

[0137] On the one hand, for the base polymer for a negative resist material, an acid-labile group is not necessarily required. Examples of such base polymers include those containing repeating unit b and optionally further containing 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, and even 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 repeating unit f is at least one selected from repeating units f1 to f3, f = f1 + f2 + f3. Also, b + c + d + e + f = 1.0.

[0138] To synthesize the base polymer, for example, monomers that provide the aforementioned repeating units may be heated in an organic solvent with the addition of a radical polymerization initiator to perform polymerization.

[0139] Examples of the organic solvent used during polymerization include toluene, benzene, THF, diethyl ether, dioxane, etc. Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, lauroyl peroxide, etc. The temperature during polymerization is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0140] When copolymerizing a monomer containing a hydroxy group, the hydroxy group may be substituted with an acetal group that is easily deprotected by an acid such as an ethoxyethoxy group before polymerization and then deprotected with a weak acid and water after polymerization, or it may be substituted with an acetyl group, a formyl group, a pivaloyl group, etc. and then subjected to alkaline hydrolysis after polymerization.

[0141] 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.

[0142] 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.

[0143] The base polymer preferably has an Mw of 1,000 to 500,000, and more preferably 2,000 to 30,000. When the Mw is within the above range, the resist film has good heat resistance and good solubility in an alkaline developer.

[0144] Furthermore, when the Mw / Mn of the base polymer is broad, there is a risk that foreign matter will be found on the pattern after exposure or that the shape of the pattern will be deteriorated due to the presence of low-molecular-weight and high-molecular-weight polymers. 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 that is suitable for use with fine pattern dimensions, it is preferable that the Mw / Mn of the base polymer has a narrow dispersion of 1.0 to 2.0, particularly 1.0 to 1.5.

[0145] The base polymer may include two or more polymers having different composition ratios, Mw, and Mw / Mn.

[0146] [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 resist material of the present invention can function as a chemically amplified positive resist material or a chemically amplified negative resist material.

[0147] 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.

[0148] 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]

[0149] 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.

[0150] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0151] R 101~R 105 The 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 of such alkyl groups 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 having 2 to 20 carbon atoms, such as a vinyl group, a propenyl group, a butenyl group, or a hexenyl group; and an ethynyl group. alkynyl groups having 2 to 20 carbon atoms, such as a propynyl group or a butynyl group; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 20 carbon atoms, such as a cyclohexenyl group or a norbornenyl group; 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 or a tert-butylnaphthyl group; aralkyl groups having 7 to 20 carbon atoms, such as a benzyl group or a phenethyl group; and groups obtained by combining these.

[0152] In addition, some or all of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, these groups may contain a hydroxy group, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, or the like.

[0153] Also, R 101 and R 102 and 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 .)

[0154] Examples of the cation of the sulfonium salt represented by formula (1-1) include, but are not limited to, those shown below. [ka]

[0155] [ka]

[0156] [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 heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups 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 bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, etc. Examples of hydrocarbyl groups containing heteroatoms include a tetrahydrofuryl group, a methoxymethyl group, an ethoxymethyl group, a methylthiomethyl group, an acetamidomethyl group, a trifluoroethyl group, a (2-methoxyethoxy)methyl group, an acetoxymethyl group, a 2-carboxy-1-cyclohexyl group, a 2-oxopropyl group, a 4-oxo-1-adamantyl group, 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 the same anions as those exemplified as the anion represented by formula (1A) in JP 2018-197853 A.

[0180] 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 fb2 means 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.

[0181] 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 R111 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.

[0182] 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.

[0183] 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.

[0184] Examples of the anion represented by formula (1D) include the same anions as those exemplified as the anion represented by formula (1D) in JP 2018-197853 A.

[0185] 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.

[0186] As the photoacid generator, a compound represented by the following formula (2) can also be suitably used. [ka]

[0187] 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 may be any of the groups represented by R 101 and R 102 and the sulfur atom to which they are bonded to form a ring, the same as those exemplified above.

[0188] R 201 and R 202 The 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 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]. 2,6cyclic 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 heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, etc., so that 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 bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, etc.

[0189] 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 heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, etc., so that the groups may contain hydroxy groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydrides, haloalkyl groups, etc. As the heteroatom, oxygen atoms are preferred.

[0190] 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.

[0191] 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.

[0192] In formula (2), k is an integer of 0 to 3.

[0193] The photoacid generator represented by formula (2) is preferably one represented by the following formula (2'). [ka]

[0194] 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.

[0195] 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.

[0196] 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.

[0197] The photoacid generator may be a sulfonium salt or an iodonium salt containing an anion having 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]

[0198] 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.

[0199] 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.

[0200] 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.

[0201] 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.

[0202] 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 20 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.

[0203] 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.

[0204] 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.

[0205] 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 bond, or a sulfonate ester bond. 402 and R 403 and 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.

[0206] 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).

[0207] 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]

[0208] [ka]

[0209]

change

[0210]

change

[0211]

change

[0212]

change

[0213]

change

[0214]

change

[0215]

change

[0216]

change

[0217]

change

[0218]

change

[0219]

change

[0220]

change

[0221]

change

[0222]

change

[0223]

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[0224]

change

[0225]

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[0226]

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[0227]

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[0228]

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[0229]

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[0230] 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.

[0231] [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.

[0232] 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.

[0233] [Other ingredients] In addition to the above-mentioned components, a quencher other than the ammonium salt and the fluorine atom-containing polymer (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 or a negative resist material, whereby 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 or 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 a margin of exposure, and the process adaptability is excellent, and the pattern shape after exposure is good, while the dimensional difference between the coarse and fine areas is small, in particular because the acid diffusion can be suppressed, and therefore the resist material is highly practical and can be very effective as a resist material for VLSI.

[0234] 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.

[0235] Other examples of the other quenchers include amine compounds having an aromatic group substituted with an iodine atom, as described in JP 2020-027297 A. These have a sensitizing effect due to their high EUV absorption, and a high acid diffusion control effect due to their large molecular weight.

[0236] Other examples of the 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 undergo a deprotection reaction, and therefore function as quenchers.

[0237] Examples of such quenchers include a compound represented by the following formula (4) (an onium salt of a sulfonic acid not fluorinated at the α-position) and a compound represented by the following formula (5) (an onium salt of a carboxylic acid). [ka]

[0238] In formula (4), R 501 represents a hydrocarbyl group having 1 to 40 carbon atoms which may contain a hydrogen atom or a heteroatom, but excludes those in which the hydrogen atom bonded to the carbon atom at the α-position of the sulfo group is substituted with a fluorine atom or a fluoroalkyl group.

[0239] The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0]. 2,6cyclic saturated hydrocarbyl groups such as ]decanyl group, adamantyl group, and adamantylmethyl group; alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group, and hexenyl group; cyclic unsaturated aliphatic hydrocarbyl groups such as cyclohexenyl group; aryl groups such as phenyl group, naphthyl group, alkylphenyl group (2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-n-butylphenyl group, etc.), dialkylphenyl group (2,4-dimethylphenyl group, 2,4,6-triisopropylphenyl group, etc.), alkylnaphthyl group (methylnaphthyl group, ethylnaphthyl group, etc.), dialkylnaphthyl group (dimethylnaphthyl group, diethylnaphthyl group, etc.); heteroaryl groups such as thienyl group; and aralkyl groups such as benzyl group, 1-phenylethyl group, and 2-phenylethyl group.

[0240] In addition, a portion of the hydrogen atoms of these groups may be substituted with a heteroatom-containing group 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 heteroatom-containing group 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 bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, or the like. Examples of hydrocarbyl groups containing heteroatoms include alkoxyphenyl groups such as 4-hydroxyphenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group, 4-ethoxyphenyl group, 4-tert-butoxyphenyl group, and 3-tert-butoxyphenyl group; alkoxynaphthyl groups such as methoxynaphthyl group, ethoxynaphthyl group, n-propoxynaphthyl group, and n-butoxynaphthyl group; dialkoxynaphthyl groups such as dimethoxynaphthyl group and diethoxynaphthyl group; and aryloxoalkyl groups such as 2-aryl-2-oxoethyl group, 2-(1-naphthyl)-2-oxoethyl group, and 2-(2-naphthyl)-2-oxoethyl group.

[0241] In formula (5), R 502R is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. 502 The hydrocarbyl group represented by R 501 Examples of the hydrocarbyl group include the same as those exemplified above. Other specific examples include fluorine-containing alkyl groups such as a trifluoromethyl group, a trifluoroethyl group, a 2,2,2-trifluoro-1-methyl-1-hydroxyethyl group, and a 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl group; and fluorine-containing aryl groups such as a pentafluorophenyl group and a 4-trifluoromethylphenyl group.

[0242] In formulas (4) and (5), Mq + is an onium cation. The onium cation is preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and more preferably a sulfonium cation or an iodonium cation. The sulfonium cation may be the same as the cation exemplified in the sulfonium salt represented by formula (1-1). The iodonium cation may be the same as the cation exemplified in the iodonium salt represented by formula (1-2).

[0243] As the quencher, a sulfonium salt of an iodized benzene ring-containing carboxylic acid represented by the following formula (6) can also be suitably used. [ka]

[0244] In formula (6), x' is an integer of 1 to 5. y' is an integer of 0 to 3. z' is an integer of 1 to 3.

[0245] In formula (6), R 601represents a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms, or a saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms, in which some or all of the hydrogen atoms may be substituted with halogen atoms, or -N(R 601A )-C(=O)-R 601B Or -N(R 601A )-C(=O)-OR 601B R 601A is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 601B is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms.

[0246] In formula (6), L 11 is a single bond or a (z'+1)-valent linking group having 1 to 20 carbon atoms, and may contain an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group, or a carboxyl group. The saturated hydrocarbyl group, the saturated hydrocarbyloxy group, the saturated hydrocarbylcarbonyloxy group, and the saturated hydrocarbylsulfonyloxy group may be linear, branched, or cyclic. When y' and / or z' is 2 or more, each R 601 may be the same or different from each other.

[0247] In formula (6), R 602 , R 603 and R 604 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 105Examples 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, an oxo group, a cyano group, a nitro 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 bond, or a sulfonate ester bond. 602 and R 603 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached.

[0248] Specific examples of the compound represented by formula (6) include those described in JP 2017-219836 A. This also has high absorption, a high sensitizing effect, and a high acid diffusion control effect.

[0249] Other examples of the other quenchers include the polymer-type quencher described in JP 2008-239918 A. This enhances the rectangularity of the resist pattern by being oriented 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.

[0250] 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 can be used alone or in combination of two or more kinds.

[0251] 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.

[0252] 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.

[0253] 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.

[0254] 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.

[0255] Examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0256] 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.

[0257] 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.

[0258] 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.

[0259] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0260] Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0261] 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.

[0262] 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.

[0263] 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.

[0264] [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.

[0265] 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.

[0266] 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 2The 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.

[0267] After the exposure, post-exposure baking (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.

[0268] 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 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 dissolves.

[0269] 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.

[0270] 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.

[0271] 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.

[0272] 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.

[0273] 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.

[0274] Examples of aromatic solvents include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[0275] 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.

[0276] 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

[0277] The present invention will be specifically described below with reference to Synthesis Examples, Comparative Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples.

[0278] [1] Synthesis of monomer [Synthesis Examples 1-1 to 1-17, Comparative Synthesis Example 1-1] 2-(dimethylamino)ethyl methacrylate and pentafluorobenzoic acid were mixed in a molar ratio of 1:1 to obtain monomer M-1. Similarly, monomers M-2 to M-17 and monomer cM-1 were obtained by mixing a nitrogen atom-containing monomer with a fluorine atom-substituted carboxylic acid compound, a fluorine atom-substituted sulfonamide compound, a fluorine atom-substituted phenol compound, a fluorine atom-substituted β-diketone compound, or a comparative example of unsubstituted benzoic acid. [ka]

[0279] [ka]

[0280] [2] Polymer synthesis The structures of the fluorine atom-containing monomers FM-1 to FM-11 and the PAG monomer PM-1 used in the synthesis of the polymer are shown below. [ka]

[0281] [ka]

[0282] [Synthesis Example 2-1] Synthesis of Polymer AP-1 In a 2L flask, 3.7g of M-1, 26.5g of FM-1, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-1. The composition of AP-1 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0283] [Synthesis Example 2-2] Synthesis of Polymer AP-2 In a 2L flask, 3.3g of M-1, 20.8g of FM-1, 6.6g of 3,3,4,4,5,5,6,6,6-nonafluorohexyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-2. The composition of AP-2 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0284] [Synthesis Example 2-3] Synthesis of Polymer AP-3 In a 2L flask, 4.4g of M-2, 20.8g of FM-1, 6.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-3. The composition of AP-3 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0285] [Synthesis Example 2-4] Synthesis of Polymer AP-4 In a 2L flask, 3.0g of M-3, 34.0g of FM-2, 6.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-4. The composition of AP-4 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0286] [Synthesis Example 2-5] Synthesis of Polymer AP-5 In a 2L flask, 3.6g of M-4, 24.0g of FM-3, 7.1g of 1,1,1,3,3,3-hexafluoroisopropyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-5. The composition of AP-5 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0287] [Synthesis Example 2-6] Synthesis of Polymer AP-6 In a 2L flask, 3.2g of M-5, 18.0g of FM-4, 7.1g of 1,1,1,3,3,3-hexafluoroisopropyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-6. The composition of AP-6 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0288] [Synthesis Example 2-7] Synthesis of Polymer AP-7 In a 2L flask, 4.2g of M-6, 26.5g of FM-5, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-7. The composition of AP-7 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0289] [Synthesis Example 2-8] Synthesis of Polymer AP-8 In a 2L flask, 4.2g of M-7, 43.0g of FM-6, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-8. The composition of AP-8 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0290] [Synthesis Example 2-9] Synthesis of Polymer AP-9 In a 2L flask, 4.3g of M-8, 15.7g of FM-7, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-9. The composition of AP-9 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0291] [Synthesis Example 2-10] Synthesis of Polymer AP-10 In a 2L flask, 5.1g of M-9, 19.7g of FM-8, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-10. The composition of AP-10 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0292] [Synthesis Example 2-11] Synthesis of Polymer AP-11 In a 2L flask, 3.3g of M-10, 20.7g of FM-8, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-11. The composition of AP-11 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0293] [Synthesis Example 2-12] Synthesis of polymer AP-12 In a 2L flask, 3.5g of M-11, 19.7g of FM-8, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-12. The composition of AP-12 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0294] [Synthesis Example 2-13] Synthesis of polymer AP-13 In a 2L flask, 4.3g of M-12, 19.7g of FM-8, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-13. The composition of AP-13 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0295] [Synthesis Example 2-14] Synthesis of polymer AP-14 In a 2L flask, 3.8g of M-13, 19.7g of FM-8, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-14. The composition of AP-14 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0296] [Synthesis Example 2-15] Synthesis of Polymer AP-15 In a 2L flask, 3.7g of M-14, 19.7g of FM-8, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-15. The composition of AP-15 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0297] [Synthesis Example 2-16] Synthesis of Polymer AP-16 In a 2L flask, 3.8g of M-13, 11.9g of FM-9, 9.8g of FM-8, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-16. The composition of AP-16 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0298] [Synthesis Example 2-17] Synthesis of polymer AP-17 In a 2L flask, 3.4g of M-15, 11.7g of FM-10, 9.8g of FM-8, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-17. The composition of AP-17 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0299] [Synthesis Example 2-18] Synthesis of polymer AP-18 In a 2L flask, 3.7g of M-14, 19.7g of FM-8, 13.3g of FM-11, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-18. The composition of AP-18 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0300] [Synthesis Example 2-19] Synthesis of Polymer AP-19 In a 2L flask, 3.7g of M-16, 26.2g of FM-8, 7.4g of PM-1, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-19. The composition of AP-19 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0301] [Synthesis Example 2-20] Synthesis of Polymer AP-20 In a 2L flask, 2.7g of M-17, 19.7g of FM-8, 9.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer AP-20. The composition of AP-20 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0302] [Comparative Synthesis Example 2-1] Synthesis of Comparative Polymer cP-1 In a 2L flask, 40.0g of FM-2, 6.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain a comparative polymer cP-1. The composition of cP-1 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0303] [Comparative Synthesis Example 2-2] Synthesis of Comparative Polymer cP-2 In a 2L flask, 1.6g of 2-(dimethylamino)ethyl methacrylate, 35.0g of FM-2, 6.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain a comparative polymer cP-2. The composition of cP-2 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0304] [Comparative Synthesis Example 2-3] Synthesis of Comparative Polymer cP-3 In a 2L flask, 2.8g of cM-1, 35.0g of FM-2, 6.0g of 1H,1H,5H-octafluoropentyl methacrylate, and 60g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and reacted for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain a comparative polymer cP-3. The composition of cP-3 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0305] [Synthesis Examples 3-1 and 3-2] Synthesis of base polymers BP-1 and BP-2 Each monomer was combined and copolymerized in THF, a solvent. The reaction solution was poured into methanol, and the precipitated solid was washed repeatedly with hexane, isolated, and dried to obtain the base polymers (BP-1 and BP-2) with the following compositions. The resulting base polymers had the following compositions: 1 Mw and Mw / Mn were confirmed by H-NMR and GPC (solvent: THF, standard: polystyrene). [ka]

[0306] [3] Preparation and evaluation of resist materials [Examples 1 to 25, Comparative Examples 1 to 5] (1) Preparation of resist material Resist materials were prepared by filtering solutions prepared by dissolving each component in the composition shown in Tables 1 and 2 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 23 and 25 and Comparative Examples 1 to 4 are positive-type, and the resist materials of Example 24 and Comparative Example 5 are negative-type.

[0307] In Tables 1 and 2, the components are as follows. Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) DAA (Diacetone Alcohol)

[0308] Acid generator: PAG-1~PAG-4 [ka]

[0309] Quencher: Q-1~Q-4 [ka]

[0310] (2) EUV lithography evaluation Each resist material shown in Tables 1 and 2 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 substrate was pre-baked at 100°C for 60 seconds using a hot plate to produce a resist film with a thickness of 40 nm. Using an EUV scanner NXE3300 (NA 0.33, σ 0.9, 90-degree dipole illumination) manufactured by ASML, a 18 nm line and space (LS) 1:1 pattern was exposed on the positive resist film, and a 22 nm LS 1:1 pattern was exposed on the negative resist film, and PEB was performed on a hot plate at the temperatures listed in Tables 1 and 2 for 60 seconds, and development was performed with a 2.38 mass% TMAH aqueous solution for 30 seconds to obtain LS patterns with dimensions of 18 nm in Examples 1 to 23, 25 and Comparative Examples 1 to 4, and LS patterns with dimensions of 22 nm in Example 24 and Comparative Example 5. Using a Hitachi High-Technologies Corporation length measuring SEM (CG5000), the exposure dose when the LS pattern was formed at 1:1 was measured as the sensitivity, and the LWR was measured at this time. The window was calculated by subtracting the dimension of the thinnest line that does not collapse in the high exposure area from the dimension of the thickest line that does not cause stringy bridges between lines in the low exposure area. The results are shown in Tables 1 and 2.

[0311] [Table 1]

[0312] [Table 2]

[0313] As shown in Tables 1 and 2, the resist material to which the ammonium salt and the fluorine atom-containing polymer were added had high sensitivity, a small LWR, and a wide window.

Claims

1. A resist material comprising a repeating unit AU having an ammonium salt structure including a carboxylate anion that contains fluorine atoms but not iodine atoms or bromine atoms, a sulfonamide anion that contains fluorine atoms but not iodine atoms or bromine atoms, a phenoxide anion that contains fluorine atoms but not iodine atoms or bromine atoms, or an enolate anion of a β-diketone that contains fluorine atoms but not iodine atoms or bromine atoms, and an ammonium salt and fluorine atom-containing polymer including at least one selected from a repeating unit FU-1 having a trifluoromethyl alcohol group optionally substituted with an acid labile group and a repeating unit FU-2 having a fluorinated hydrocarbyl group, and a base polymer, A resist material in which the repeating unit AU is represented by the following formula (AU), the repeating unit FU-1 is represented by the following formula (FU-1), and the repeating unit FU-2 is represented by the following formula (FU-2). 【Chemistry 1】 [In the formula, n 1 is 1 or 2. 2 is 0 < n 2 / n 1 n is a positive number that satisfies ≦1. 3 is 1 or 2. R A are each independently a hydrogen atom or a methyl group. X 1A is a single bond, a phenylene group, an ester bond or an amide bond. X 1B is a single bond or a carbon number of 1 to 20 (n 1 The hydrocarbon group may contain an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxy group, or a carboxy group. X 2A represents a single bond, a phenylene group, -O-, -C(=O)-O- or -C(=O)-NH-. X 2B is a carbon number of 1 to 12 (n 3 +1)-valent saturated hydrocarbon group or (n 3 It is a (+1)-valent aromatic hydrocarbon group, which may contain a fluorine atom, a hydroxy group, an ester bond, or an ether bond. X 3 represents a single bond, a phenylene group, -O-, -C(=O)-O-X 31 -X 32 - or -C(=O)-NH-X 31 -X 32 - is. 31 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. 32 is a single bond, an ester bond, an ether bond or a sulfonamide bond. R 1 , R 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. 1 and R 2 and or R 1 and X 1B may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and the ring may contain an oxygen atom, a sulfur atom, a nitrogen atom or a double bond. R 4 represents a single bond, an ester bond, or a saturated hydrocarbylene group having 1 to 12 carbon atoms, some or all of the hydrogen atoms of the saturated hydrocarbylene group may be substituted with fluorine atoms, and some of the carbon atoms of the saturated hydrocarbylene group may be substituted with ester bonds or ether bonds. R 5 R is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a difluoromethyl group. 5 and R 6 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the ring may contain an ether bond, a fluorine atom, or a trifluoromethyl group. R 6 is a hydrogen atom or an acid labile group. R 7 is a hydrocarbyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, some of the carbon atoms of which may be substituted with an ester bond or an ether bond. X - is a carboxylate anion which contains a fluorine atom but does not contain an iodine atom or a bromine atom, a sulfonamide anion which contains a fluorine atom but does not contain an iodine atom or a bromine atom, a phenoxide anion which contains a fluorine atom but does not contain an iodine atom or a bromine atom, or an enolate anion of a β-diketone which contains a fluorine atom but does not contain an iodine atom or a bromine atom, which is represented by the following formula (an-1). 【Chemistry 2】 (In the formula, R a1 is a fluorinated aryl group having 1 to 30 carbon atoms or a fluorinated heteroaryl group having 2 to 30 carbon atoms, and the fluorinated aryl group and the fluorinated heteroaryl group may contain a hydroxy group, an amino group, a nitro group or a thiol group.)

2. The sulfonamide anion is represented by the following formula (an-2), and the phenoxide anion is represented by the following formula (an-3):

2. The resist material according to claim 1, wherein the enolate anion of the β-diketone is represented by the following formula (an-4): 【Chemistry 3】 (In the formula, R a2 is a fluorine atom or a fluorinated hydrocarbyl group having 1 to 10 carbon atoms, and the fluorinated hydrocarbyl group may contain a hydroxy group, an ether bond, an ester bond, an amide bond or a thiol group. R a3 is a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms, and the hydrocarbyl group may contain a hydroxy group, an ether bond or an ester bond. m 1 and m 2 are integers satisfying 1≦m 1 ≦5, 0≦m 2 ≦3 and 1≦m 1 +m 2 ≦5. R a4 is a fluorine atom, a trifluoromethyl group or a 1,1,1,3,3,3-hexafluoro-2-propanol group. R a5 is a hydroxy group, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbylcarbonyl group having 2 to 7 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbylcarbonyloxy group having 2 to 7 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxycarbonyl group having 2 to 7 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms which may be substituted with a halogen atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, -N(R a5A )-C(═O)-R a5B or -N(R a5A )-C(═O)-O-R a5B R a5A is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R a5B is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms. R a6 is a fluorinated hydrocarbyl group having 1 to 10 carbon atoms, a hydrocarbyl group having 1 to 10 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms. R a7 is a fluorinated hydrocarbyl group having 1 to 10 carbon atoms.

3. The resist material according to claim 1, wherein X − is a sulfonamide anion containing fluorine atoms but not containing iodine atoms or bromine atoms, a phenoxide anion containing fluorine atoms but not containing iodine atoms or bromine atoms, or an enolate anion of a β-diketone containing fluorine atoms but not containing iodine atoms or bromine atoms.

4. 4. The resist material according to claim 1, wherein the ammonium salt and the fluorine atom-containing polymer are contained in an amount of 0.001 to 20 parts by mass per 100 parts by mass of the base polymer.

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

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

7. The resist material according to any one of claims 1 to 6, 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 2】 (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. R 13 is a fluorine atom, a trifluoromethyl group, a saturated hydrocarbyl group having 1 to 5 carbon atoms, or a saturated hydrocarbyloxy group having 1 to 5 carbon atoms. Y 1 is a divalent linking group having 1 to 12 carbon atoms 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. a is an integer from 0 to 4.

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

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

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

11. The resist material according to any one of claims 1 to 10, wherein the base polymer contains a repeating unit represented by any one of the following formulas (f1) to (f3): 【Chemistry 3】 (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 or an ester bond. Z 3 is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -O-C(=O)-. Z 31 represents a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group obtained by combining these and having 7 to 18 carbon atoms, which may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom. Z 4 is a methylene group, a 2,2,2-trifluoro-1,1-ethanediyl group, or a carbonyl group. Z 5 represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -O-Z 51 -, -C(=O)-O-Z 51 - or -C(=O)-NH-Z 51 - is. 51 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 and or R 26 and R 27 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached. M - is a non-nucleophilic counterion.)

12. The resist material according to any one of claims 1 to 11, further comprising a surfactant.

13. 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 12; exposing the resist film to high-energy radiation; and developing the exposed resist film using a developer.

14. 14. The method for forming a pattern according to claim 13, 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.

15. 14. The pattern formation method according to claim 13, 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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