Resist composition and pattern forming process

Abstract

The present invention addresses the problem of providing a resist material with high sensitivity in both positive and negative modes, and improved LWR and CDU, as well as a patterning method using the resist material. The solution to this problem is a resist material containing a strontium salt of an iodinated phenol compound.

Description

Technical Field

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

[0002] With the increasing integration and speed of LSIs, the miniaturization of pattern patterns is also progressing rapidly. This is driven by the widespread adoption of 5G high-speed communications and artificial intelligence (AI), which necessitates high-performance devices to handle them. Among the most advanced miniaturization technologies, mass production of 5nm node devices using extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm is already underway. Furthermore, the use of EUV lithography for devices at the next-generation 3nm node and the next-generation 2nm node is also underway. IMEC in Belgium has already announced the development of a 2Å device.

[0003] As miniaturization progresses, image blurring caused by acid diffusion has become a problem. To ensure resolution for fine patterns under 45 nm in size, it has been proposed that controlling acid diffusion is crucial, in addition to improving dissolution contrast, as previously advocated (Non-Patent Document 1). However, chemically amplified resist materials utilize acid diffusion to improve sensitivity and contrast. Therefore, reducing the post-exposure bake (PEB) temperature or time to minimize acid diffusion significantly reduces sensitivity and contrast.

[0004] The three-way trade-off between sensitivity, resolution, and edge roughness (LWR) is demonstrated. To improve resolution, acid diffusion must be suppressed, but shortening the acid diffusion distance reduces sensitivity.

[0005] Adding an acid generator that generates a bulky acid to inhibit acid diffusion is effective. Therefore, some have proposed incorporating repeating units derived from an onium salt with a polymerizable unsaturated bond into a polymer. In this case, the polymer also functions as an acid generator (polymer-bonded acid generator). Patent Document 1 proposes coronium salts and iodonium salts with a polymerizable unsaturated bond that generate specific sulfonic acids. Patent Document 2 proposes coronium salts with a sulfonic acid directly bonded to the backbone.

[0006] The acid-labile groups in the (meth)acrylate polymers used in ArF resist materials undergo a deprotection reaction when using a photoacid generator that generates a sulfonic acid with a fluorine atom substituted at the α-position. However, acid generators that generate a sulfonic acid or carboxylic acid with no fluorine atom substituted at the α-position do not undergo a deprotection reaction. When a coronium salt or iodonium salt that generates a sulfonic acid with no fluorine atom substituted at the α-position is mixed with a coronium salt or iodonium salt that generates a sulfonic acid with no fluorine atom substituted at the α-position, the coronium salt or iodonium salt that generates the sulfonic acid with no fluorine atom substituted at the α-position undergoes ion exchange with the sulfonic acid with fluorine atom substituted at the α-position. The sulfonic acid with fluorine atom substituted at the α-position generated by light irradiation reverts to the coronium salt or iodonium salt through ion exchange, allowing the coronium salt or iodonium salt of the sulfonic acid or carboxylic acid with no fluorine atom substituted at the α-position to function as a quencher. Resist materials using coronium salts or iodonium salts that generate carboxylic acids as quenchers have been proposed (Patent Document 3).

[0007] Some have proposed using coronium salts of phenol compounds with fluorinated benzene rings as quenchers in resist materials (Patent Documents 4 and 5). Coronium salts of phenol compounds decompose to form phenol, which swells less in alkaline developers, effectively preventing pattern collapse caused by swelling. However, fluorine has a low inhibitory effect on acid diffusion, which increases acid diffusion and degrades LWR and dimensional uniformity (CDU). Furthermore, coronium salts of fluorinated phenol compounds are susceptible to thermal decomposition during preparation due to their low acidity. This poses a problem in resist materials with increased sensitivity during storage. [Prior Art Literature] [Patent Document]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-045311 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-178317 [Patent Document 3] Japanese Patent Application Laid-Open No. 2007-114431 [Patent Document 4] Japanese Patent Application Laid-Open No. 2016-6495 [Patent Document 5] Japanese Patent Application Publication No. 2019-191578 [Non-patent literature]

[0009] [Non-Patent Document 1] SPIE Vol. 6520 65203L-1 (2007) Summary of the Invention

[0010] [Problems to be solved by the invention] There is a desire to develop a quencher in resist materials that can improve the LWR of line patterns, the CDU of hole patterns, and also improve sensitivity. Therefore, it is necessary to further reduce image blurring caused by diffusion.

[0011] The present invention is made in view of the above circumstances, and its purpose is to provide a resist material with high sensitivity in both positive and negative modes and improved LWR and CDU, as well as a pattern forming method using the same. [Methods for solving the problem]

[0012] To achieve the aforementioned objectives, the present inventors conducted repeated and in-depth studies and discovered that a coronium salt of an iodinated phenol compound serves as a quencher that inhibits acid diffusion. This excellent acid diffusion inhibition, along with reduced swelling to prevent pattern collapse and improved contrast due to strong absorption of iodine atoms, allows for the production of a resist material with improved LWR and CDU, excellent resolution, and wide process latitude. Furthermore, due to the high acidity of iodinated phenol, its coronium salt is not susceptible to thermal decomposition, resulting in excellent storage stability of the resist material containing it, leading to the completion of the present invention.

[0013] That is, the present invention provides the following resist material and pattern forming method. 1. A resist material comprising: a coronium salt of an iodinated phenol compound. 2. The resist material according to 1., wherein the aforementioned coronium salt is represented by the following formula (1). [Chemistry 1] Wherein, m is 1, 2, 3, 4 or 5. n is 0, 1, 2, 3 or 4. However, 1 ≤ m + n ≤ 5. R1 is each independently a halogen atom other than an iodine atom, a hydroxyl group, a nitro group, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, or a hydrocarbon sulfonyloxy group having 1 to 20 carbon atoms, and the hydrocarbon group, hydrocarbon oxy group, hydrocarbon carbonyloxy group, and hydrocarbon sulfonyloxy group may also have at least one selected from the group consisting of a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. R2 to R4 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. In addition, R2 and R3 may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. 3. The resist material as in 1. or 2. further comprising a base polymer. 4. The resist material according to 3., wherein the base polymer contains at least one selected from the group consisting of a repeating unit represented by the following formula (a1) and a repeating unit represented by the following formula (a2). [Chemistry 2] In the formula, RA are each independently a hydrogen atom or a methyl group. X1 is a single bond, a phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, an ether bond, and a lactone ring, and the phenylene group, naphthylene group, and linking group may also have at least one selected from a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms, and a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms. X2 is a single bond, an ester bond or an amide bond. X3 is a single bond, an ether bond or an ester bond. R 11 and R 12 are each independently an acid-labile group. R 13 is a hydroxyl group, a halogen atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and a portion of the -CH 2- group of the alkanediyl group may be substituted by an ether bond or an ester bond. a is 1 or 2. b is an integer from 0 to 4. However, 1 ≤ a + b ≤ 5. 5. The resist material as in 4 is a chemically amplified positive resist material. 6. The resist material according to 3., wherein the base polymer does not contain acid-labile groups. 7. The resist material as in 6. is a chemically amplified negative-type resist material. 8. The resist material according to any one of items 3. to 7., wherein the base polymer comprises at least one selected from the group consisting of a repeating unit represented by the following formula (f1), a repeating unit represented by the following formula (f2), a repeating unit represented by the following formula (f3), a repeating unit represented by the following formula (f4), and a repeating unit represented by the following formula (f5). [Chemistry 3] In the formula, RA are each independently a hydrogen atom or a methyl group. Z1 is a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms derived from a combination thereof, or -OZ11-, -C(=O)-OZ11-, or -C(=O)-NH-Z11-. Z11 is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms derived from a combination thereof, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z2 is a single bond or an ester bond. Z3 is a single bond, -Z31-C(=O)-O-, -Z31-O-, or -Z31-OC(=O)-. Z31 is an aliphatic alkylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms derived from a combination thereof, and may also contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom. Z 4 is methylene, 2,2,2-trifluoro-1,1-ethanediyl or carbonyl. Z 5 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with a trifluoromethyl group, -OZ 51-, -C(=O)-OZ 51-, or -C(=O)-NH-Z 51-. Z 51 is an aliphatic hydrocarbon alkylene group having 1 to 6 carbon atoms, phenylene, fluorinated phenylene, or phenylene substituted with a trifluoromethyl group, and may also contain a carbonyl group, an ester bond, an ether bond, a halogen atom, or a hydroxyl group. Z6 is a single bond, a phenylene group, a naphthylene ring, an ester bond, or an amide bond. Z 7A is a single bond or a divalent organic group having 1 to 24 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. Z 7B is a monovalent organic group having 1 to 10 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. Z 8 is a single bond, an ether bond, an ester bond, a thioether bond, or an alkanediyl group having 1 to 6 carbon atoms. Z9 is a trivalent organic group having 1 to 12 carbon atoms, and may have at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom. R 21 to R 25 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. R 23 and R 24 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. R 26 is each independently a saturated hydrocarbon group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a fluorine atom, an iodine atom, a trifluoromethoxy group, a difluoromethoxy group, a cyano group, or a nitro group. R is a (j+2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms. j is independently an integer from 0 to 5. M- is a non-nucleophilic counter ion. 9. The resist material according to any one of 1. to 8. further comprising an acid generator that generates a strong acid. 10. The resist material according to claim 9, wherein the acid generator generates sulfonic acid, imidic acid, or methylated acid. 11. The resist material according to any one of 1. to 10. further contains an organic solvent. 12. The resist material according to any one of 1. to 11. further comprising a surfactant. 13. A pattern forming method comprising the following steps: Using any one of the resist materials in 1. to 12. to form a resist film on a substrate, exposing the resist film to high energy radiation, and The exposed resist film is developed using a developer. 14. The pattern forming method of 13., wherein the high-energy radiation is KrF excimer laser light, ArF excimer laser light, electron beam (EB) or EUV radiation with a wavelength of 3 to 15 nm. [Effects of the Invention]

[0014] The coronium salt of the iodinated phenol compound described above acts as a quencher that inhibits acid diffusion. This allows the construction of a resist material with low acid diffusion characteristics, a low LWR, and improved CDU. Implementation Method

[0015] [Resist material] The resist material of the present invention contains a quencher comprising a coronium salt of an iodinated phenol compound.

[0016] [Quencher] The coronium salt of the iodinated phenol compound is preferably represented by the following formula (1). [Chemistry 4]

[0017] In formula (1), m is 1, 2, 3, 4, or 5. n is 0, 1, 2, 3, or 4. However, 1≦m+n≦5.

[0018] In formula (1), R 1 is independently a halogen atom other than an iodine atom, a hydroxyl group, a nitro group, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, or a hydrocarbon sulfonyloxy group having 1 to 20 carbon atoms.

[0019] The hydrocarbon group represented by R1 and the hydrocarbon radical portion of the hydrocarbonoxy group, hydrocarboncarbonyloxy group, and hydrocarbonsulfonyloxy group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples include the same examples as those exemplified below for the hydrocarbon groups having 1 to 20 carbon atoms represented by R2 to R4. Furthermore, the aforementioned hydrocarbon groups, hydrocarbonoxy groups, hydrocarboncarbonyloxy groups, and hydrocarbonsulfonyloxy groups may have at least one selected from the group consisting of a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. That is, a part or all of the hydrogen atoms of these groups may be substituted by a group containing at least one selected from a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom, and a part of the -CH2- of these groups may be substituted by a group containing at least one selected from an oxygen atom, a sulfur atom, and a nitrogen atom. As a result, these groups may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like.

[0020] Specific examples of the anion of the bismuth salt represented by formula (1) include the following, but are not limited thereto. [Chemistry 5]

[0021] [Chemistry 6]

[0022] [Chemistry 7]

[0023] [Chemistry 8]

[0024] [Chemistry 9]

[0025] [Chemistry 10]

[0026] [Chemistry 11]

[0027] [Chemistry 12]

[0028] [Chemistry 13]

[0029] [Chemistry 14]

[0030] [Chemistry 15]

[0031] [Chemistry 16]

[0032] In formula (1), R 2 to R 4 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom.

[0033] Specific examples of the halogen atom represented by R 2 to R 4 include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

[0034] The hydrocarbon group having 1 to 20 carbon atoms represented by R 2 to R 4 may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include: alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; vinyl, propenyl, butenyl, and hexenyl; Alkenyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, and butynyl; alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, and butynyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, secondary butylphenyl, tertiary butylphenyl, naphthyl, methyl naphthyl, ethyl naphthyl, n-propyl naphthyl, isopropyl naphthyl, n-butyl naphthyl, isobutyl naphthyl, secondary butyl naphthyl, and tertiary butyl naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl and phenethyl; and groups derived from combinations thereof.

[0035] Furthermore, some or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- groups of the aforementioned hydrocarbon group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, the hydrocarbon group may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, mercapto groups, pentafluorosulfanyl groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, and the like.

[0036] Furthermore, R2 and R3 may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the ring is preferably a structure as shown below. [Chemistry 17] In the formula, the dotted line is the atomic bond with R 4.

[0037] Specific examples of the cation of the bismuth salt represented by formula (1) include the following, but are not limited thereto. [Chemistry 18]

[0038] [Chemistry 19]

[0039] [Chemistry 20]

[0040] [Chemistry 21]

[0041] [Chemistry 22]

[0042] [Chemistry 23]

[0043] [Chemistry 24]

[0044] [Chemistry 25]

[0045] [Chemistry 26]

[0046] [Chemistry 27]

[0047] [Chemistry 28]

[0048] [Chemistry 29]

[0049] [Chemistry 30]

[0050] [Chemistry 31]

[0051] [Chemistry 32]

[0052] [Chemistry 33]

[0053] [Chemistry 34]

[0054] [Chemistry 35]

[0055] [Chemistry 36]

[0056] [Chemistry 37]

[0057] [Chemistry 38]

[0058] [Chemistry 39]

[0059] [Chemistry 40]

[0060] [Chemistry 41]

[0061] [Chemistry 42]

[0062] [Chemistry 43]

[0063] [Chemistry 44]

[0064] [Chemistry 45]

[0065] [Chemistry 46]

[0066] [Chemistry 47]

[0067] [Chemistry 48]

[0068] [Chemistry 49]

[0069] [Chemistry 50]

[0070] [Chemistry 51]

[0071] [Chemistry 52]

[0072] The coronium salt represented by formula (1) can be synthesized by, for example, exchanging a hydrochloride or carbonate having a coronium cation with an ammonium salt of an iodinated phenol compound.

[0073] In the resist material of the present invention, the content of the coronium salt represented by formula (1) is preferably 0.001 to 50 parts by mass, more preferably 0.01 to 40 parts by mass, relative to 100 parts by mass of the base polymer described below. The coronium salt represented by formula (1) may be used alone or in combination of two or more.

[0074] [Base polymer] The base polymer contained in the resist material of the present invention, in the case of a positive-type resist material, may contain 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 referred to as repeating unit a1) or a repeating unit represented by the following formula (a2) (hereinafter referred to as repeating unit a2). [Chemistry 53]

[0075] In formulas (a1) and (a2), RA is each independently a hydrogen atom or a methyl group. X is a single bond, a phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, an ether bond, and a lactone ring. The phenylene group, naphthylene group, and linking group may also contain at least one selected from a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms, and a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms. X is a single bond, an ester bond, or an amide bond. X is a single bond, an ether bond, or an ester bond. R and R are each independently an acid-labile group. R is a hydroxyl group, a halogen atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbon group having 1 to 6 carbon atoms. R is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and a portion of the -CH2- group of the alkanediyl group may be substituted with an ether bond or an ester bond. a is 1 or 2. b is an integer from 0 to 4. However, 1≦a+b≦5.

[0076] Specific examples of the monomer providing the repeating unit a1 include, but are not limited to, the following. In the following formula, RA and R 11 are the same as those described above. [Chemistry 54]

[0077] [Chemistry 55]

[0078] Specific examples of monomers providing repeating unit a2 include, but are not limited to, the following. In the following formula, RA and R 12 are the same as those described above. [Chemistry 56]

[0079] There are various options for the acid-labile group represented by R 11 or R 12, for example, those represented by the following formulas (AL-1) to (AL-3). [Chemistry 57] In the formula, the dotted lines are atomic bonds.

[0080] In formula (AL-1), c is an integer from 0 to 6. RL1 represents a tertiary hydrocarbon group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, a trihydrocarbylsilyl group in which each hydrocarbon group is a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon group having 4 to 20 carbon atoms containing a carbonyl group, an ether bond, or an ester bond, or a group represented by formula (AL-3). A tertiary hydrocarbon group refers to a group derived from a tertiary carbon atom of a hydrocarbon by removing a hydrogen atom.

[0081] The tertiary hydrocarbon group represented by R L1 may be saturated or unsaturated, branched, or cyclic. Specific examples include tertiary butyl, tertiary pentyl, 1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, and 2-methyl-2-adamantyl. Specific examples of the aforementioned trihydrocarbylsilyl group include trimethylsilyl, triethylsilyl, and dimethyl-tertiary butylsilyl. The aforementioned saturated hydrocarbon group containing a carbonyl group, an ether bond, or an ester bond may be linear, branched, or cyclic, and is preferably cyclic. Specific examples thereof include 3-oxocyclohexyl, 4-methyl-2-oxooxan-4-yl, 5-methyl-2-oxooxolan-5-yl, 2-tetrahydropyranyl, and 2-tetrahydrofuranyl.

[0082] Specific examples of the acid-labile group represented by formula (AL-1) include a tertiary butoxycarbonyl group, a tertiary butoxycarbonylmethyl group, a tertiary pentyloxycarbonyl group, a tertiary pentyloxycarbonylmethyl group, a 1,1-diethylpropyloxycarbonyl group, a 1,1-diethylpropyloxycarbonylmethyl group, a 1-ethylcyclopentyloxycarbonyl group, a 1-ethylcyclopentyloxycarbonylmethyl group, a 1-ethyl-2-cyclopentenyloxycarbonyl group, a 1-ethyl-2-cyclopentenyloxycarbonylmethyl group, a 1-ethoxyethoxycarbonylmethyl group, a 2-tetrahydropyranyloxycarbonylmethyl group, and a 2-tetrahydrofuranyloxycarbonylmethyl group.

[0083] In addition, the acid-labile group represented by formula (AL-1) may also include groups represented by the following formulas (AL-1)-1 to (AL-1)-10. [Chemistry 58] In the formula, the dotted lines are atomic bonds.

[0084] In formulas (AL-1)-1 to (AL-1)-10, c is the same as described above. RL8 each independently represents a saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. RL9 represents a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. RL10 represents a saturated hydrocarbon group having 2 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic.

[0085] In formula (AL-2), RL2 and RL3 are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, and n-octyl.

[0086] In formula (AL-2), RL4 represents a hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, which may contain heteroatoms. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples of the hydrocarbon group include saturated hydrocarbon groups having 1 to 18 carbon atoms, and some of these hydrogen atoms may be substituted with hydroxyl groups, alkoxy groups, pendant oxy groups, amino groups, alkylamino groups, and the like. Specific examples of such substituted saturated hydrocarbon groups include those listed below. [Chemistry 59] In the formula, the dotted lines are atomic bonds.

[0087] RL2 and RL3, RL2 and RL4, or RL3 and RL4 may also be bonded to each other and form a ring together with the carbon atom to which they are bonded, or together with a carbon atom and an oxygen atom to form a ring. In this case, RL2 and RL3, RL2 and RL4, or RL3 and RL4 participating in the ring formation are each independently an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The number of carbon atoms in the ring formed by these bonding groups is preferably 3 to 10, more preferably 4 to 10.

[0088] Specific examples of linear or branched acid-labile groups represented by formula (AL-2) include, but are not limited to, those represented by the following formulas (AL-2)-1 to (AL-2)-69. In the following formulas, dotted lines represent atomic bonds. [Chemistry 60]

[0089] [Chemistry 61]

[0090] [Chemistry 62]

[0091] [Chemistry 63]

[0092] Specific examples of the acid-labile groups represented by formula (AL-2) include cyclic groups such as tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, and 2-methyltetrahydropyran-2-yl.

[0093] Examples of the acid-labile group include groups represented by the following formula (AL-2a) or (AL-2b). The base polymer can also be cross-linked between or within molecules using the acid-labile group. [Chemistry 64] In the formula, the dotted lines are atomic bonds.

[0094] In formula (AL-2a) or (AL-2b), R L11 and R L12 are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic. Furthermore, R L11 and R L12 may be bonded to each other and, together with the carbon atoms to which they are bonded, form a ring. In this case, R L11 and R L12 are each independently an alkanediyl group having 1 to 8 carbon atoms. R L13 is each independently a saturated hydrocarbon alkylene group having 1 to 10 carbon atoms. The saturated hydrocarbon alkylene group may be linear, branched, or cyclic. d and e are each independently an integer from 0 to 10, preferably an integer from 0 to 5. f is an integer from 1 to 7, preferably an integer from 1 to 3.

[0095] In formula (AL-2a) or (AL-2b), LA is an (f+1)-valent aliphatic saturated hydrocarbon group with 1 to 50 carbon atoms, an (f+1)-valent alicyclic saturated hydrocarbon group with 3 to 50 carbon atoms, an (f+1)-valent aromatic hydrocarbon group with 6 to 50 carbon atoms, or an (f+1)-valent heterocyclic group with 3 to 50 carbon atoms. Furthermore, a portion of the -CH2- groups in these groups may be substituted with a group containing a heteroatom, and a portion of the hydrogen atoms in these groups may be substituted with a hydroxyl group, a carboxyl group, an acyl group, or a fluorine atom. LA is preferably a saturated hydrocarbon group such as a saturated hydrocarbon group with 1 to 20 carbon atoms, a trivalent saturated hydrocarbon group, a tetravalent saturated hydrocarbon group, or an aryl group with 6 to 30 carbon atoms. The aforementioned saturated hydrocarbon group may be linear, branched, or cyclic. LB is -C(=O)-O-, -NH-C(=O)-O-, or -NH-C(=O)-NH-.

[0096] Specific examples of the cross-linking acetal group represented by formula (AL-2a) or (AL-2b) include groups represented by the following formulas (AL-2)-70 to (AL-2)-77. [Chemistry 65] In the formula, the dotted lines are atomic bonds.

[0097] In formula (AL-3), RL5 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, which may contain heteroatoms such as oxygen, sulfur, nitrogen, or fluorine atoms. RL6 and RL7 are each independently a hydrocarbon group having 1 to 20 carbon atoms, which may contain heteroatoms such as oxygen, sulfur, nitrogen, or fluorine atoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, and aryl groups having 6 to 10 carbon atoms. RL5 and RL6, RL5 and RL7, or RL6 and RL7 may be bonded to each other and, together with the carbon atoms to which they are bonded, form an alicyclic ring having 3 to 20 carbon atoms.

[0098] Specific examples of the group represented by formula (AL-3) include a tertiary butyl group, a 1,1-diethylpropyl group, a 1-ethylnorbornyl group, a 1-methylcyclopentyl group, a 1-ethylcyclopentyl group, a 1-isopropylcyclopentyl group, a 1-methylcyclohexyl group, a 2-(2-methyl)adamantyl group, a 2-(2-ethyl)adamantyl group, and a tertiary pentyl group.

[0099] Furthermore, examples of the group represented by the formula (AL-3) include groups represented by the following formulae (AL-3)-1 to (AL-3)-22. [Chemistry 66] In the formula, the dotted lines are atomic bonds.

[0100] In formulas (AL-3)-1 to (AL-3)-22, RL14 is independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 8 carbon atoms, or an aryl group having 6 to 20 carbon atoms. RL15 and RL17 are independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms. RL16 is an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic. The aryl group is preferably a phenyl group. RL18 is a fluorine atom, an iodine atom, a nitro group, or a trifluoromethyl group. RL19 is independently a hydrogen atom, a fluorine atom, an iodine atom, a nitro group, a saturated hydrocarbon group having 1 to 8 carbon atoms, or a hydrocarbonoxy group having 1 to 8 carbon atoms. g is an integer from 1 to 5.

[0101] In addition, the acid-labile group may be a group represented by the following formula (AL-3)-23 or (AL-3)-24. The acid-labile group may be used to crosslink the polymer intramolecularly or intermolecularly. [Chemistry 67] In the formula, the dotted lines are atomic bonds.

[0102] In formulas (AL-3)-23 and (AL-3)-24, RL14 is the same as described above. RL20 is a saturated or unsaturated hydrocarbon alkylene group having 1 to 20 carbon atoms and a valence of (h+1), or an aryl alkylene group having 6 to 20 carbon atoms and a valence of (h+1), and may contain heteroatoms such as oxygen, sulfur, and nitrogen atoms. The saturated or unsaturated hydrocarbon alkylene group may be linear, branched, or cyclic. h is an integer of 1 to 3.

[0103] In addition to these acid-labile groups, acid-labile groups containing aromatic groups described in Japanese Patent Nos. 5565293, 5434983, 5407941, 5655756, and 5655755 can also be used.

[0104] The base polymer may also contain a repeating unit b containing a phenolic hydroxyl group as an adhesive group. Specific examples of monomers providing repeating unit b include, but are not limited to, the following. In the following formula, RA is the same as described above. [Chemistry 68]

[0105] The base polymer may also contain repeating units C containing hydroxyl groups other than phenolic hydroxyl groups, lactone rings, sultone rings, ether bonds, ester bonds, sulfonate bonds, carbonyl groups, sulfonyl groups, cyano groups, or carboxyl groups as other adhesive groups. Specific examples of monomers providing repeating units C include, but are not limited to, the following. In the following formula, RA is the same as described above. [Chemistry 69]

[0106] [Chemistry 70]

[0107] [Chemistry 71]

[0108] [Chemistry 72]

[0109] [Chemistry 73]

[0110] [Chemistry 74]

[0111] [Chemistry 75]

[0112] [Chemistry 76]

[0113] The base polymer may also contain a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthene, chromone, coumarin, norbornadiene, or a derivative thereof. Specific examples of monomers providing the repeating unit d include, but are not limited to, the following. [Chemistry 77]

[0114] The aforementioned base polymer may also contain repeating units e derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methylenedihydroindane, vinylpyridine or vinylcarbazole.

[0115] The base polymer may also contain a repeating unit f derived from an onium salt containing a polymerizable unsaturated bond. Specific examples of desirable 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), a repeating unit represented by the following formula (f3) (hereinafter also referred to as repeating unit f3), a repeating unit represented by the following formula (f4) (hereinafter also referred to as repeating unit f4), and a repeating unit represented by the following formula (f5) (hereinafter also referred to as repeating unit f5). Repeating units f1 to f5 may be used alone or in combination of two or more. [Chemistry 78]

[0116] In formulas (f1) to (f5), RA is independently a hydrogen atom or a methyl group.

[0117] In formulas (f1) to (f3), Z 1 is a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms derived from a combination thereof, or -OZ 11-, -C(=O)-OZ 11-, or -C(=O)-NH-Z 11-. Z 11 is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms derived from a combination thereof, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl 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 is an aliphatic alkylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms derived from a combination thereof, and may also 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-. Z 51 is an aliphatic alkylene 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 also contain a carbonyl group, an ester bond, an ether bond, a halogen atom, or a hydroxyl group. The aliphatic hydrocarbylene groups represented by Z1, Z11, Z31, and Z51 may be saturated or unsaturated, and may be linear, branched, or cyclic.

[0118] In formulas (f4) and (f5), Z 6 is a single bond, a phenylene group, a naphthylene ring, an ester bond, or an amide bond.

[0119] In formula (f4), Z 7A is a single bond or a divalent organic group having 1 to 24 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom.

[0120] The divalent organic group represented by Z 7A may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include a C1-24 alkylene group in which some or all of the hydrogen atoms are substituted with iodine or bromine atoms. Specific examples of the aforementioned alkylene group having 1 to 24 carbon atoms include: methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, heptadecane-1,17-diyl, octadecane-1,18-diyl, nonadecane-1,19-diyl, eicosane-1,20-diyl, and the like; cyclopentane Cyclic saturated alkylene groups such as cyclopentanediyl, methylcyclopentanediyl, dimethylcyclopentanediyl, trimethylcyclopentanediyl, tetramethylcyclopentanediyl, cyclohexanediyl, methylcyclohexanediyl, dimethylcyclohexanediyl, trimethylcyclohexanediyl, tetramethylcyclohexanediyl, norbornanediyl, and adamantanediyl; arylene groups such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, secondary butylphenylene, tertiary butylphenylene, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, secondary butylnaphthyl, tertiary butylnaphthyl, biphenyldiyl, methylbiphenyldiyl, and dimethylbiphenyldiyl; and groups derived from combinations thereof. Furthermore, some or all of the hydrogen atoms of Z 7A may be substituted with groups containing at least one selected from the group consisting of an oxygen atom, a nitrogen atom, and a sulfur atom, and some of the -CH 2- groups of Z 7A may be substituted with groups containing at least one selected from the group consisting of an oxygen atom, a nitrogen atom, and a sulfur atom, and as a result, may contain a hydroxyl group, an ester bond, an ether bond, an amide bond, a urethane bond, a urea bond, or the like.

[0121] In formula (f5), Z 7B is a monovalent organic group having 1 to 10 carbon atoms, and may have at least one selected from the group consisting of a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom.

[0122] The monovalent organic group represented by Z 7B may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples include hydrocarbon groups having 1 to 10 carbon atoms in which some or all of the hydrogen atoms are substituted with iodine or bromine atoms. Specific examples of the aforementioned hydrocarbon group having 1 to 10 carbon atoms include: alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, n-pentyl, isopentyl, secondary pentyl, 3-pentyl, tertiary pentyl, neopentyl, n-hexyl, n-octyl, n-nonyl, and n-decyl; cyclic saturated hydrocarbon groups having 3 to 10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, methylcyclopropyl, methylcyclobutyl, methylcyclopentyl, methylcyclohexyl, ethylcyclopropyl, ethylcyclobutyl, ethylcyclopentyl, and ethylcyclohexyl; vinyl, 1- Alkenyl groups having 2 to 10 carbon atoms, such as propenyl, 2-propenyl, butenyl, pentenyl, hexenyl, heptenyl, nonenyl, and decenyl; alkynyl groups having 2 to 10 carbon atoms, such as ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonynyl, and decynyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 10 carbon atoms, such as cyclopentenyl, cyclohexenyl, methylcyclopentenyl, methylcyclohexenyl, ethylcyclopentenyl, ethylcyclohexenyl, and norbornyl; aryl groups having 6 to 10 carbon atoms, such as phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, secondary butylphenyl, tertiary butylphenyl, and naphthyl; aralkyl groups having 7 to 10 carbon atoms, such as benzyl, phenethyl, phenylpropyl, and phenylbutyl; and groups derived from combinations thereof. Furthermore, some or all of the hydrogen atoms of Z 7B may be substituted with a group containing at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom, and some of the -CH 2 - groups of Z 7B may be substituted with a group containing at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom, and as a result, a hydroxyl group, an ester bond, an ether bond, an amide bond, a urethane bond, a urea bond, or the like may be contained.

[0123] In formulas (f4) and (f5), Z 8 is a single bond, an ether bond, an ester bond, a thioether bond, or an alkanediyl group having 1 to 6 carbon atoms.

[0124] In formula (f5), Z 9 is a trivalent organic group having 1 to 12 carbon atoms, and may contain at least one selected from oxygen, nitrogen, and sulfur atoms. The trivalent organic group represented by Z 9 may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include groups derived from a hydrocarbylene group having 1 to 12 carbon atoms by removing one hydrogen atom. Specific examples of the aforementioned hydrocarbylene group having 1 to 12 carbon atoms include those having 1 to 12 carbon atoms among the aforementioned hydrocarbylene groups having 1 to 24 carbon atoms. Furthermore, some or all of the hydrogen atoms in Z 9 may be substituted with groups containing at least one selected from oxygen, nitrogen, and sulfur atoms, and some of the -CH 2- groups in Z 9 may be substituted with groups containing at least one selected from oxygen, nitrogen, and sulfur atoms. Consequently, the group may contain hydroxyl groups, ester bonds, ether bonds, amide bonds, urethane bonds, urea bonds, and the like.

[0125] In formulas (f1) to (f5), R 21 to R 25 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples include the same examples as those exemplified as the hydrocarbon groups represented by R 2 to R 4 in the description of formula (1). Furthermore, some or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted with groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- groups of the aforementioned hydrocarbon group may be substituted with groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. Consequently, the hydrocarbon group may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, and the like. Furthermore, R23 and R24 may be bonded to each other and, together with the sulfur atom to which they are bonded, form a ring. Specific examples of the aforementioned ring include the same examples as those exemplified in the description of formula (a) as the ring that can be formed by R2 and R3 bonded to each other and together with the sulfur atom to which they are bonded.

[0126] In formulae (f4) and (f5), R 26 is independently a saturated hydrocarbon group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a fluorine atom, an iodine atom, a trifluoromethoxy group, a difluoromethoxy group, a cyano group, or a nitro group.

[0127] In formulas (f4) and (f5), R is a (j+2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms. Specific examples of the (j+2)-valent aromatic hydrocarbon group include groups derived from aromatic hydrocarbons such as benzene and naphthalene by removing (j+2) hydrogen atoms.

[0128] In formulas (f4) and (f5), j is independently an integer from 0 to 5.

[0129] In formula (f1), M- is a non-nucleophilic counterion. Specific examples of the non-nucleophilic counterion include halide ions such as chloride ion and bromide ion; fluoroalkylsulfonate ions such as trifluoromethanesulfonate ion, 1,1,1-trifluoroethanesulfonate ion, and nonafluorobutanesulfonate ion; arylsulfonate ions such as toluenesulfonate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion, and 1,2,3,4,5-pentafluorobenzenesulfonate ion; alkylsulfonate ions such as methanesulfonate ion and butanesulfonate ion; imide ions such as bis(trifluoromethylsulfonyl)imide ion, bis(perfluoroethylsulfonyl)imide ion, and bis(perfluorobutylsulfonyl)imide ion; and methyl ions such as trifluoromethylsulfonylmethyl ion and trifluoroethylsulfonylmethyl ion.

[0130] Specific examples of the aforementioned non-nucleophilic counterions include: a sulfonate ion represented by the following formula (f1-1) in which the α-position is substituted with a fluorine atom, 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, and the like. [Chemistry 79]

[0131] In formula (f1-1), R 31 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. The hydrocarbon group may contain at least one selected from an ether bond, an ester bond, a carbonyl group, a lactone ring, and a fluorine atom. The hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those exemplified for the hydrocarbon group represented by R fa1 in formula (2A') described below.

[0132] In formula (f1-2), R 32 is a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a hydrocarbon carbonyl group having 2 to 30 carbon atoms. The hydrocarbon group and hydrocarbon carbonyl group may contain at least one selected from an ether bond, an ester bond, a carbonyl group, and a lactone ring. The hydrocarbon moiety of the hydrocarbon group and hydrocarbon carbonyl group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those for the hydrocarbon group represented by R f1 in formula (2A') described below.

[0133] Specific examples of the cation of the monomer providing the repeating unit f1 include, but are not limited to, the following: In the following formula, RA is the same as described above. [Chemistry 80]

[0134] Specific examples of the cations of the repeating units f2 to f5 are the same as those exemplified as the cations of the stibium salt represented by formula (1).

[0135] Specific examples of the anion of the monomer providing the repeating unit f2 include, but are not limited to, the following. [Chemistry 81]

[0136] [Chemistry 82]

[0137] [Chemistry 83]

[0138] [Chemistry 84]

[0139] [Chemistry 85]

[0140] [Chemistry 86]

[0141] [Chemistry 87]

[0142] [Chemistry 88]

[0143] [Chemistry 89]

[0144] [Chemistry 90]

[0145] [Chemistry 91]

[0146] [Chemistry 92]

[0147] [Chemistry 93]

[0148] [Chemistry 94]

[0149] [Chemistry 95]

[0150] Specific examples of the anion of the monomer providing the repeating unit f3 include, but are not limited to, the following. [Chemistry 96]

[0151] Specific examples of the anion of the monomer providing the repeating unit f4 or f5 include, but are not limited to, the following. In the following formula, RA and XBI are the same as those described above. [Chemistry 97]

[0152] [Chemistry 98]

[0153] [Chemistry 99]

[0154] [Chemistry 100]

[0155] [Chemistry 101]

[0156] [Chemistry 102]

[0157] [Chemistry 103]

[0158] [Chemistry 104]

[0159] [Chemistry 105]

[0160] [Chemistry 106]

[0161] [Chemistry 107]

[0162] [Chemistry 108]

[0163] [Chemistry 109]

[0164] [Chemistry 110]

[0165] [Chemistry 111]

[0166] [Chemistry 112]

[0167] [Chemistry 113]

[0168] [Chemistry 114]

[0169] [Chemistry 115]

[0170] [Chemistry 116]

[0171] [Chemical formula 117]

[0172] [Chemical formula 118]

[0173] [Chemical formula 119]

[0174] [Chemical formula 120]

[0175] [Chemical formula 121]

[0176] The repeating units f1 to f5 function as an acid generator. By bonding the acid generator to the polymer main chain, acid diffusion can be reduced, and a decrease in resolution caused by blurring of acid diffusion can be prevented. Also, by uniformly dispersing the acid generator, LWR and CDU are improved. In addition, when using a base polymer containing the repeating units f1 to f5 (i.e., a polymer-bonded acid generator), the blending of the additive acid generator described later can be omitted.

[0177] The base polymer for a positive resist material needs to contain the repeating unit a1 or a2 having an acid-labile group. At this time, 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. In addition, when the repeating unit f is at least one selected from the repeating units f1 to f5, f = f1 + f2 + f3 + f4 + f5. Also, a1 + a2 + b + c + d + e + f = 1.0.

[0178] On the other hand, for the base polymer used in the negative resist material, an acid-labile group is not necessary. Such base polymers include those containing the repeating unit b, and optionally further containing the repeating units c, d, e, and / or f. The content ratios of these repeating units are preferably 0 < b ≤ 1.0, 0 ≤ c ≤ 0.9, 0 ≤ d ≤ 0.8, 0 ≤ e ≤ 0.8, and 0 ≤ f ≤ 0.5, more preferably 0.2 ≤ b ≤ 1.0, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.7, 0 ≤ e ≤ 0.7, and 0 ≤ f ≤ 0.4, and still more preferably 0.3 ≤ b ≤ 1.0, 0 ≤ c ≤ 0.75, 0 ≤ d ≤ 0.6, 0 ≤ e ≤ 0.6, and 0 ≤ f ≤ 0.3. In addition, when the repeating unit f is at least one selected from the repeating units f1 to f5, f = f1 + f2 + f3 + f4 + f5. Also, b + c + d + e + f = 1.0.

[0179] Examples of the method for synthesizing the aforementioned base polymer include, for example, a method of adding a radical polymerization initiator and heating monomers that provide the aforementioned repeating units in an organic solvent to carry out polymerization.

[0180] Specific examples of the organic solvent used in the polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, dioxane, propylene glycol monomethyl ether, γ-butyrolactone, and mixed solvents thereof. Specific 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.

[0181] When copolymerizing a hydroxyl-containing monomer, the hydroxyl group can be replaced with an acetal group such as ethoxyethoxy that is easily deprotected by an acid prior to polymerization, and deprotection can be carried out using a weak acid and water after polymerization. Alternatively, it can be replaced with an acetyl group, a formyl group, a trimethylacetyl group, etc. prior to polymerization, and base hydrolysis can be carried out after polymerization.

[0182] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, hydroxystyrene and hydroxyvinylnaphthalene can also be replaced with acetoxystyrene and acetoxyvinylnaphthalene, and after polymerization, the acetoxy group can be deprotected by the aforementioned base hydrolysis to become hydroxystyrene and hydroxyvinylnaphthalene.

[0183] The base used in the base hydrolysis can be ammonia water, triethylamine, etc. Also, 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.

[0184] The polystyrene-equivalent weight average molecular weight (Mw) of the base polymer, as determined by gel permeation chromatography (GPC) using THF as a solvent, is preferably 1,000 to 500,000, more preferably 2,000 to 30,000. When the Mw is within this range, the resist film exhibits excellent heat resistance and solubility in alkaline developer solutions.

[0185] Furthermore, if the molecular weight distribution (Mw / Mn) of the base polymer is wide, the presence of low-molecular-weight and high-molecular-weight polymers can lead to visible foreign matter and deterioration of the pattern shape after exposure. As pattern sizes become finer, the influence of Mw and Mw / Mn increases. Therefore, to obtain a resist material ideally suited for fine pattern sizes, the base polymer Mw / Mn should ideally be between 1.0 and 2.0, with a narrow distribution of 1.0 to 1.5 being particularly preferred.

[0186] To obtain narrowly dispersed polymers, not only conventional radical polymerization but also living radical polymerization can be used. Specific examples of living radical polymerization include nitroxide-mediated radical polymerization (NMP), atom transfer radical polymerization (ATRP), and reversible addition-fragmentation chain transfer (RAFT).

[0187] The base polymer may contain two or more polymers having different composition ratios, Mw, and Mw / Mn.

[0188] [Acid generator] The resist material of the present invention may also contain an acid generator (hereinafter also referred to as an additive acid generator) that generates a strong acid. The term "strong acid" herein refers to a compound having an acidity sufficient to cause a deprotection reaction of an acid-labile group of a base polymer in the case of a chemically amplified positive resist material, or a compound having an acidity sufficient to cause an acid-induced polarity change reaction or a crosslinking reaction in the case of a chemically amplified negative resist material. By containing such an acid generator, the coronium salt represented by the aforementioned formula (1) can function as a quencher, and the resist material of the present invention can function as a chemically amplified positive resist material or a chemically amplified negative resist material.

[0189] Examples of the acid generator include compounds that react to active light or radiation to generate an acid (photoacid generators). Any photoacid generator that generates an acid upon exposure to high-energy radiation is acceptable, but preferably generates a sulfonic acid, an imidic acid, or a methide acid. Preferred photoacid generators include coronium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate acid generators. Specific examples of photoacid generators include those described in paragraphs

[0122] to

[0142] of Japanese Patent Application Laid-Open No. 2008-111103.

[0190] Furthermore, as the photoacid generator, a coronium salt represented by the following formula (2-1) or an iodonium salt represented by the following formula (2-2) can also be preferably used. [Chemistry 122]

[0191] In formulas (2-1) and (2-2), R 101 to R 105 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples include the same examples as those exemplified as the hydrocarbon groups represented by R 2 to R 4 in the description of formula (1). Furthermore, some or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- groups of the aforementioned hydrocarbon group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, the hydrocarbon group may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydrides, and haloalkyl groups. Furthermore, R101 and R102 may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, specific examples of the aforementioned ring include the same examples as those exemplified in the description of formula (1) as the ring that can be formed by R2 and R3 bonding to each other and together with the sulfur atom to which they are bonded.

[0192] Specific examples of the cation of the coronium salt represented by formula (2-1) include the same examples as those exemplified for the cation of the coronium salt represented by formula (1).

[0193] Specific examples of the cation of the iodonium salt represented by formula (2-2) include the following, but are not limited thereto. [Chemistry 123]

[0194] [Chemistry 124]

[0195] In formulas (2-1) and (2-2), Xa- is an anion selected from the following formulas (2A) to (2D). [Chemistry 125]

[0196] In formula (2A), R fa is a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those exemplified for the hydrocarbon group represented by R fa1 in formula (2A') described below.

[0197] The anion represented by formula (2A) is preferably represented by the following formula (2A'). [Chemistry 126]

[0198] In formula (2A'), R HF is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R fa1 is a hydrocarbon group having 1 to 38 carbon atoms, which may also contain a heteroatom. The heteroatom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, or the like, with an oxygen atom being more preferred. The hydrocarbon group is particularly preferably one having 6 to 30 carbon atoms, in order to achieve high resolution in fine pattern formation.

[0199] The hydrocarbon group represented by R fa1 may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof, which are considered to achieve high resolution in fine pattern formation, include: alkyl groups having 1 to 38 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, and eicosyl, preferably alkyl groups having 6 to 30 carbon atoms; cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl Cyclic saturated hydrocarbon groups having 3 to 38 carbon atoms, such as alkyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecanyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups having 2 to 38 carbon atoms, such as allyl and 3-cyclohexenyl; aryl groups having 6 to 38 carbon atoms, such as phenyl, 1-naphthyl, and 2-naphthyl; aralkyl groups having 7 to 38 carbon atoms, such as benzyl and diphenylmethyl; and groups derived from combinations thereof.

[0200] Furthermore, some or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted with groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- groups of the aforementioned hydrocarbon groups may be substituted with groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. Consequently, the hydrocarbon groups may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, and the like. Specific examples of hydrocarbon groups containing heteroatoms include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl.

[0201] For details on the synthesis of coronium salts containing anions represented by formula (2A'), see Japanese Patent Application Laid-Open Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. Furthermore, coronium salts described in Japanese Patent Application Laid-Open Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 can also be suitably used.

[0202] Specific examples of the anion represented by formula (2A) can be the same as those exemplified as the anion represented by formula (1A) in JP-A-2018-197853.

[0203] In formula (2B), Rfb1 and Rfb2 are each independently a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms, which may contain heteroatoms. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those exemplified for the hydrocarbon group represented by Rfa1 in formula (2A'). Rfb1 and Rfb2 are preferably fluorine atoms or linear fluorinated alkyl groups having 1 to 4 carbon atoms. Furthermore, Rfb1 and Rfb2 may be bonded to each other and form a ring together with the group to which they are bonded (-CF2-SO2-N--SO2-CF2-). In this case, the group formed by the bond between Rfb1 and Rfb2 is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0204] In formula (2C), Rfc1, Rfc2, and Rfc3 are each independently a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms, which may contain a heteroatom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those exemplified for the hydrocarbon group represented by Rfa1 in formula (2A'). Rfc1, Rfc2, and Rfc3 are preferably fluorine atoms or linear fluorinated alkyl groups having 1 to 4 carbon atoms. Furthermore, Rfc1 and Rfc2 may be bonded to each other and form a ring together with the group to which they are bonded (-CF2-SO2-C --SO2-CF2-). In this case, the group formed by the bond between Rfc1 and Rfc2 is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0205] In formula (2D), Rfd represents a hydrocarbon group having 1 to 40 carbon atoms, which may contain a heteroatom. This hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those exemplified for the hydrocarbon group represented by Rfa1 in formula (2A').

[0206] For details on the synthesis of coronium salts containing anions represented by formula (2D), see Japanese Patent Application Publication Nos. 2010-215608 and 2014-133723.

[0207] Specific examples of the anion represented by formula (2D) can be the same as those exemplified as the anion represented by formula (1D) in JP-A-2018-197853.

[0208] Furthermore, the photoacid generator containing the anion represented by formula (2D) has no fluorine atom at the α-position of the sulfonic acid group but has two trifluoromethyl groups at the β-position. Therefore, it has sufficient acidity to cleave acid-labile groups in the base polymer. Therefore, it can be used as a photoacid generator.

[0209] As the photoacid generator, a photoacid generator represented by the following formula (3) can also be preferably used. [Chemistry 127]

[0210] In formula (3), R201 and R202 are each independently a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom. R203 is a hydrocarbon alkylene group having 1 to 30 carbon atoms which may contain a heteroatom. Furthermore, any two of R201, R202, and R203 may be bonded to each other and, together with the sulfur atom to which they are bonded, form a ring. In this case, specific examples of the aforementioned ring include the same examples as those exemplified in the description of formula (1) as the ring that can be formed when R2 and R3 are bonded to each other and together with the sulfur atom to which they are bonded.

[0211] The hydrocarbon group represented by R 201 and R 202 may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include: alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, n-pentyl, tertiary pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, oxanorbornyl, tricyclo[5.2.1.0 Cyclic saturated hydrocarbon groups having 3 to 30 carbon atoms, such as 2,6]decyl and adamantyl; aryl groups having 6 to 30 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, secondary butylphenyl, tertiary butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, secondary butylnaphthyl, tertiary butylnaphthyl, and anthracenyl; and groups derived from combinations thereof. Furthermore, some or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- groups of the aforementioned hydrocarbon group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, the hydrocarbon group may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, and the like.

[0212] The alkylene group represented by R 203 may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, heptane-1,17-diyl, and heptadecane-1,18-diyl. alkylene groups having 1 to 30 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, and adamantanediyl; cyclic saturated hydrocarbon groups having 3 to 30 carbon atoms, such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, secondary butylphenylene, tertiary butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, secondary butylnaphthylene, and tertiary butylnaphthylene; and groups derived from combinations thereof. Furthermore, some or all of the hydrogen atoms of the aforementioned hydrocarbylene group may be substituted with groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- groups of the aforementioned hydrocarbylene group may be substituted with groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. Consequently, the hydrocarbylene group may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, and the like. The aforementioned heteroatoms are preferably oxygen atoms.

[0213] In formula (3), LC represents a single bond, an ether bond, or a hydrocarbon alkylene group having 1 to 20 carbon atoms which may contain heteroatoms. The hydrocarbon alkylene group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those exemplified for the hydrocarbon alkylene group represented by R 203.

[0214] In formula (3), XA, XB, XC, and XD are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. However, at least one of XA, XB, XC, and XD is a fluorine atom or a trifluoromethyl group.

[0215] In formula (3), k is an integer between 0 and 3.

[0216] The photoacid generator represented by formula (3) is preferably represented by the following formula (3'). [Chemistry 128]

[0217] In formula (3'), LC is the same as described above. XE is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R301, R302, and R303 are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those for the hydrocarbon group represented by Rfa1 in formula (2A'). x and y are each independently an integer from 0 to 5, and z is an integer from 0 to 4.

[0218] Specific examples of the photo-acid generator represented by formula (3) include the same examples as those exemplified as the photo-acid generator represented by formula (2) in Japanese Patent Application Laid-Open No. 2017-026980.

[0219] Among the aforementioned photoacid generators, those containing anions represented by formula (2A') or (2D) are particularly preferred because they have low acid diffusion and excellent solubility in solvents. Furthermore, those represented by formula (3') are particularly preferred because they have extremely low acid diffusion.

[0220] The photoacid generator may also be a coronium salt or iodonium salt containing an anion having an aromatic ring substituted with an iodine atom or a bromine atom. Specific examples of such salts include those represented by the following formula (4-1) or (4-2). [Chemistry 129]

[0221] In formulas (4-1) and (4-2), 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.

[0222] In formulae (4-1) and (4-2), XBI is an iodine atom or a bromine atom, and when p and / or q are 2 or more, they may be the same as or different from each other.

[0223] In formulas (4-1) and (4-2), L1 is a single bond, an ether bond, an ester bond, or a saturated hydrocarbon group having 1 to 6 carbon atoms that may contain an ether bond or an ester bond. The saturated hydrocarbon group may be linear, branched, or cyclic.

[0224] In formulas (4-1) and (4-2), L2 is a single bond or a divalent linking group having 1 to 20 carbon atoms when p is 1, and is a (p+1)-valent linking group having 1 to 20 carbon atoms when p is 2 or 3, and the linking group may also contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0225] In formulas (4-1) and (4-2), R 401 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, or an amino group; or a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbonoxy group having 1 to 20 carbon atoms, a hydrocarboncarbonyl group having 2 to 20 carbon atoms, a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms, or a hydrocarbonsulfonyloxy group having 1 to 20 carbon atoms, which may also contain a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amino group, or an ether bond; or -N(R 401A)(R 401B), -N(R 401C)-C(═O)-R 401D, or -N(R 401C)-C(═O)-OR 401D. R 401A and R 401B are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R401C is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms. R401D is an aliphatic hydrocarbon 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 hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. The aforementioned hydrocarbon groups, hydrocarbon oxy groups, hydrocarbon carbonyl groups, hydrocarbon oxycarbonyl groups, hydrocarbon carbonyloxy groups, and hydrocarbon sulfonyloxy groups may be linear, branched, or cyclic. When p and / or r is 2 or more, each R 401 may be the same as or different from each other.

[0226] Among them, R 401 is preferably a hydroxyl group, -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 or the like.

[0227] In formulas (4-1) and (4-2), Rf1-Rf4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that at least one of them is a fluorine atom or a trifluoromethyl group. Furthermore, Rf1 and Rf2 may combine to form a carbonyl group. It is particularly preferred that both Rf3 and Rf4 are fluorine atoms.

[0228] In formulas (4-1) and (4-2), R402 to R406 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. Specific examples of the aforementioned halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The aforementioned hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those exemplified as the hydrocarbon groups represented by R2 to R4 in the description of formula (1). Furthermore, some or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted with a hydroxyl group, a carboxyl group, a halogen atom, a cyano group, a nitro group, a mercapto group, a sultone ring, a sulfo group, or a group containing a thiocyanate, and some of the -CH2- groups of the aforementioned hydrocarbon group may be substituted with an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond, or a sulfonate bond. Furthermore, R402 and R403 may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, specific examples of the aforementioned ring include the same examples as those exemplified in the description of formula (1) as the ring that can be formed when R2 and R3 are bonded to each other and together with the sulfur atom to which they are bonded.

[0229] Specific examples of the cation of the coronium salt represented by formula (4-1) include the same examples as those exemplified above for the cation of the coronium salt represented by formula (1). Specific examples of the cation of the iodonium salt represented by formula (4-2) include the same examples as those exemplified above for the cation of the iodonium salt represented by formula (2-2).

[0230] Specific examples of the anion of the onium salt represented by formula (4-1) or (4-2) include the following, but are not limited thereto. In the following formula, XBI is the same as above. [Chemistry 130]

[0231] [Chemistry 131]

[0232] [Chemistry 132]

[0233] [Chemistry 133]

[0234] [Chemistry 134]

[0235] [Chemistry 135]

[0236] [Chemistry 136]

[0237] [Chemistry 137]

[0238] [Chemistry 138]

[0239] [Chemistry 139]

[0240] [Chemistry 140]

[0241] [Chemistry 141]

[0242] [Chemistry 142]

[0243] [Chemistry 143]

[0244] [Chemistry 144]

[0245] [Chemistry 145]

[0246] [Chemistry 146]

[0247] [Chemistry 147]

[0248] [Chemistry 148]

[0249] [Chemistry 149]

[0250] [Chemistry 150]

[0251] [Chemistry 151]

[0252] [Chemistry 152]

[0253] As the photoacid generator, a coronium salt or iodonium salt of fluorobenzenesulfonic acid bonded to iodinated benzoic acid represented by the following formula (4-3) or (4-4) may be used. [Chemistry 153]

[0254] In formulas (4-3) and (4-4), s is an integer from 1 to 5, t is an integer from 0 to 3, and u is an integer from 1 to 4.

[0255] In formulas (4-3) and (4-4), R 411 is a hydroxyl group, a carboxyl group, an alkoxycarbonyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, or a saturated hydrocarbon group having 1 to 20 carbon atoms, a saturated hydrocarbonoxy group having 1 to 20 carbon atoms, or a saturated hydrocarboncarbonyloxy group having 2 to 20 carbon atoms which may also contain a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amino group, or an alkoxy group, or -N(R 411A)-C(═O)-R 411B or -N(R 411A)-C(═O)-OR 411B, and R 411A is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 411B is an aliphatic hydrocarbon 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 also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms.

[0256] In formulas (4-3) and (4-4), L 3 is a single bond or a divalent linking group having 1 to 20 carbon atoms, and the linking group may also contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0257] In formulas (4-3) and (4-4), Rf 11 is a fluorine atom or a trifluoromethyl group.

[0258] In formulas (4-3) and (4-4), R412 to R416 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. Specific examples of the aforementioned halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The aforementioned hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include the same examples as those exemplified as the hydrocarbon groups represented by R2 to R4 in the description of formula (1). Furthermore, some or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted with a hydroxyl group, a carboxyl group, a halogen atom, a cyano group, a nitro group, a mercapto group, a sultone ring, a sulfo group, or a group containing a thiocyanate, and some of the -CH2- groups of the aforementioned hydrocarbon group may be substituted with an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond, or a sulfonate bond. Furthermore, R402 and R403 may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, specific examples of the aforementioned ring include the same examples as those exemplified in the description of formula (1) as the ring that can be formed when R2 and R3 are bonded to each other and together with the sulfur atom to which they are bonded.

[0259] Specific examples of the cation of the coronium salt represented by formula (4-3) include the same examples as those of the cation of the coronium salt represented by formula (1). Specific examples of the cation of the iodonium salt represented by formula (4-4) include the same examples as those of the cation of the iodonium salt represented by formula (2-2).

[0260] Specific examples of the anion of the onium salt represented by formula (4-3) or (4-4) include the following, but are not limited thereto. [Chemistry 154]

[0261] [Chemistry 155]

[0262] [Chemistry 156]

[0263] [Chemistry 157]

[0264] [Chemistry 158]

[0265] When the resist material of the present invention contains the aforementioned additive acid generator, its content 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 additive acid generator may be used alone or in combination of two or more. In the resist material of the present invention, the base polymer can function as a chemically amplified resist material by containing any of the repeating units f1 to f5 and / or containing the additive acid generator.

[0266] [Organic solvents] The resist material of the present invention may also contain an organic solvent. The aforementioned organic solvent is not particularly limited as long as it can dissolve the aforementioned components and the components described below. Specific examples of the aforementioned organic solvent include: ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Laid-Open No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; propylene glycol monomethyl ether , ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether and other ethers; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tertiary butyl acetate, tertiary butyl propionate, propylene glycol monotertiary butyl ether acetate and other esters; γ-butyrolactone and other lactones, etc.

[0267] In the resist material of the present invention, the content of the aforementioned organic solvent is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, relative to 100 parts by mass of the base polymer. The aforementioned organic solvent may be used alone or as a mixture of two or more.

[0268] [Other ingredients] The resist material of the present invention may contain, in addition to the aforementioned components, a surfactant, a dissolution inhibitor, a crosslinking agent, a quencher other than the coronium salt represented by formula (1) (hereinafter also referred to as other quenchers), a water repellency improver, acetylene alcohols, etc.

[0269] Specific examples of the surfactant include those described in paragraphs

[0165] and

[0166] of Japanese Patent Application Laid-Open No. 2008-111103. The addition of a surfactant can further improve or control the coating properties of the resist material. When the resist material of the present invention contains the surfactant, its content is preferably 0.0001 to 10 parts by mass per 100 parts by mass of the base polymer. The surfactants may be used alone or in combination of two or more.

[0270] When the resist material of the present invention is positive-type, the dissolution rate difference between the exposed and unexposed areas can be further increased by incorporating a dissolution inhibitor, thereby further improving resolution. Specific examples of the dissolution inhibitor include compounds having a molecular weight preferably of 100 to 1000, more preferably 150 to 800, wherein the hydrogen atoms of the phenolic hydroxyl groups in a compound containing two or more phenolic hydroxyl groups are replaced by acid-labile groups at a ratio of 0 to 100 mol % overall, or compounds containing carboxyl groups in a compound containing carboxyl groups in a compound containing carboxyl groups at a ratio of 50 to 100 mol % overall. Specific examples include compounds in which the hydrogen atoms of the hydroxyl and carboxyl groups of bisphenol A, phenolphthalein, cresol novolac resins, naphthalenecarboxylic acid, adamantanecarboxylic acid, and bile acid are replaced by acid-labile groups, such as those described in paragraphs

[0155] to

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

[0271] When the resist material of the present invention is positive-type and contains the aforementioned dissolution inhibitor, its content is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The aforementioned dissolution inhibitors may be used alone or in combination of two or more.

[0272] On the other hand, when the resist material of the present invention is negative-type, a negative-type pattern can be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposed portion. Specific examples of the crosslinking agent include epoxy compounds substituted with at least one group selected from hydroxymethyl, alkoxymethyl, and acyloxymethyl groups, melamine compounds, guanamine compounds, glycoluril compounds, urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyloxy groups. These can be used as additives or introduced into polymer side chains as pendant groups. Hydroxyl-containing compounds can also be used as crosslinking agents.

[0273] Specific examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0274] Specific examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, compounds in which 1 to 6 hydroxymethyl groups in hexamethylolmelamine are methoxymethylated, or mixtures thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, compounds in which 1 to 6 hydroxymethyl groups in hexamethylolmelamine are acyloxymethylated, or mixtures thereof.

[0275] Specific examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, compounds in which 1 to 4 hydroxymethyl groups in tetramethylolguanamine are methoxymethylated, or mixtures thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, compounds in which 1 to 4 hydroxymethyl groups in tetramethylolguanamine are acyloxymethylated, or mixtures thereof.

[0276] Specific examples of the glycoluril compound include tetrakishydroxymethyl glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 hydroxymethyl groups in the tetrakishydroxymethyl glycoluril are methoxymethylated, or mixtures thereof, compounds in which 1 to 4 hydroxymethyl groups in the tetrakishydroxymethyl glycoluril are acyloxymethylated, or mixtures thereof. Specific examples of the urea compound include tetrakishydroxymethylurea, tetramethoxymethylurea, compounds in which 1 to 4 hydroxymethyl groups in the tetrakishydroxymethylurea are methoxymethylated, or mixtures thereof, and tetramethoxyethylurea.

[0277] Specific examples of the isocyanate compound include toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0278] Specific examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylenebisazide, and 4,4'-oxybisazide.

[0279] Specific examples of the alkenyloxy group-containing compound 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.

[0280] When the resist material of the present invention is negative-type and contains the aforementioned crosslinking agent, its content is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The aforementioned crosslinking agent may be used alone or in combination of two or more.

[0281] Specific examples of the aforementioned other quenchers include conventional basic compounds. Specific examples of conventional basic compounds include primary, secondary, or tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having carboxyl groups, nitrogen-containing compounds having sulfonyl groups, nitrogen-containing compounds having hydroxyl groups, nitrogen-containing compounds having hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. In particular, preferred are the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Laid-Open No. 2008-111103, amine compounds having a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate bond, and compounds having a carbamate group as described in Japanese Patent Application No. 3790649. By adding such a basic compound, for example, the diffusion rate of the acid in the resist film can be further suppressed or the shape can be corrected.

[0282] Other quenchers include onium salts such as coronium salts, iodonium salts, and ammonium salts of α-unfluorinated sulfonic acids and carboxylic acids described in Japanese Patent Application Laid-Open No. 2008-158339. α-fluorinated sulfonic acids, imidic acids, or methylated acids are necessary for deprotecting the acid-labile group of the carboxylate. Salt exchange with an α-unfluorinated onium salt releases the α-unfluorinated sulfonic acid or carboxylic acid. α-unfluorinated sulfonic acids and carboxylic acids do not cause deprotection reactions and therefore function as quenchers.

[0283] Other examples of quenchers include the polymer quenchers described in Japanese Patent Application Publication No. 2008-239918. These quenchers improve the rectangularity of the resist pattern by aligning on the resist film surface. Polymer quenchers also prevent film loss and doming of the pattern when using a protective film for immersion exposure.

[0284] When the resist material of the present invention contains other quenchers, their content is preferably 0-5 parts by mass, more preferably 0-4 parts by mass, relative to 100 parts by mass of the base polymer. The other quenchers may be used alone or in combination of two or more.

[0285] The aforementioned water repellency improver improves the water repellency of the resist film surface and can be used in immersion lithography without a top coat. The water repellency improver is preferably a polymer containing a fluorinated alkyl group or a polymer containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue of a specific structure, and is preferably one exemplified in Japanese Patent Application Publication Nos. 2007-297590 and 2008-111103. The water repellency improver must be soluble in both alkaline and organic solvent developers. The specific water repellency improver containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue exhibits excellent solubility in developer solutions. Polymers containing repeating units containing amine groups or amine salts are highly effective in preventing acid evaporation during PEB and preventing poor opening of the hole pattern after development. When the resist material of the present invention contains the aforementioned water repellency improver, its content is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the base polymer. The aforementioned water repellency improver may be used alone or in combination of two or more.

[0286] Specific examples of the aforementioned acetylene alcohols include those described in paragraphs

[0179] to

[0182] of Japanese Patent Application Laid-Open No. 2008-122932. When the resist material of the present invention contains the aforementioned acetylene alcohols, the content thereof is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer. The aforementioned acetylene alcohols may be used alone or in combination of two or more.

[0287] [Pattern Formation Method] When the resist material of the present invention is used in the manufacture of various integrated circuits, known lithography techniques can be used. For example, a specific example of a pattern forming method includes the following steps: Using the aforementioned resist material to form a resist film on the substrate, exposing the resist film to high energy radiation, and The exposed resist film is developed using a developer.

[0288] First, the resist material of the present invention is applied to a substrate (such as Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, or an organic antireflective film) for integrated circuit manufacturing or a substrate (such as Cr, CrO, CrON, MoSi2, or SiO2) for mask circuit manufacturing using an appropriate coating method such as spin coating, roller coating, flow coating, dip coating, spray coating, or doctor blade coating to a coating thickness of 0.01 to 2 μm. The resist material is then pre-baked on a hot plate, preferably at 60 to 150°C for 10 seconds to 30 minutes, and more preferably at 80 to 120°C for 30 seconds to 20 minutes, to form a resist film.

[0289] Then, the resist film is exposed to high-energy radiation. Specific examples of the high-energy radiation include ultraviolet radiation, extreme ultraviolet radiation, EB, EUV radiation with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer lasers, gamma rays, and synchrotron radiation. When ultraviolet radiation, extreme ultraviolet radiation, EUV radiation, X-rays, soft X-rays, excimer lasers, gamma rays, and synchrotron radiation are used as the high-energy radiation, the radiation is applied directly or through a mask used to form the desired pattern, with the exposure dose preferably being approximately 1 to 200 mJ / cm², more preferably approximately 10 to 100 mJ / cm². When EB is used as the high-energy radiation, the radiation is applied directly or through a mask used to form the desired pattern, with the exposure dose preferably being approximately 0.1 to 300 μC / cm², more preferably approximately 0.5 to 200 μC / cm². In addition, the resist material of the present invention is particularly suitable for fine patterning by high-energy radiation such as KrF excimer laser, ArF excimer laser, EB, EUV, X-ray, soft X-ray, gamma ray, and synchrotron radiation, and is particularly suitable for fine patterning by EB or EUV.

[0290] After exposure, PEB may be performed on a hot plate or in an oven, preferably at 30-150° C. for 10 seconds to 30 minutes, more preferably at 50-120° C. for 30 seconds to 20 minutes, or it may not be performed.

[0291] After exposure or PEB, the exposed resist film is developed using a developer containing an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, or tetrabutylammonium hydroxide, preferably at a concentration of 0.1-10% by mass, and more preferably 2-5% by mass, for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, using conventional methods such as dipping, pudding, or spraying. This forms the desired pattern. With positive-tone resist materials, the exposed portions dissolve in the developer, while the unexposed portions remain insoluble, resulting in the desired positive pattern on the substrate. With negative-tone resist materials, the opposite occurs: the exposed portions remain insoluble in the developer, while the unexposed portions dissolve.

[0292] Negative patterns can also be obtained by using a positive resist material containing a base polymer having an acid-labile group and developing it with an organic solvent. Specific examples of the developer used in this case include: 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate, Ethyl crotonate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl 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 may be used alone or in combination of two or more.

[0293] At the end of development, rinsing is performed. The rinsing solution should preferably be a solvent that is miscible with the developer and does not dissolve the resist film. Suitable solvents include alcohols with 3 to 10 carbon atoms, ethers with 8 to 12 carbon atoms, alkanes, alkenes, and alkynes with 6 to 12 carbon atoms, and aromatic solvents.

[0294] Specific examples of the alcohol having 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tertiary butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tertiary butyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 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, 1-octanol, etc.

[0295] Specific examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di(secondary butyl) ether, di-n-pentyl ether, diisopentyl ether, di(secondary pentyl) ether, di(tertiary pentyl) ether, and di-n-hexyl ether.

[0296] Specific examples of the aforementioned alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. Specific examples of the aforementioned alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Specific examples of the aforementioned alkynes having 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

[0297] Specific examples of the aromatic solvents include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, mesitylene, and the like.

[0298] By performing rinsing, the occurrence of resist pattern collapse and defects can be reduced. In addition, rinsing is not necessary, and by not performing rinsing, the amount of solvent used can be reduced.

[0299] After development, hole and groove patterns can also be shrunk using heat flow, RELACS, or DSA techniques. A shrinking agent is applied to the hole pattern. During baking, the diffusion of the acid catalyst from the resist film causes cross-linking of the shrinking agent on the surface of the resist film, resulting in adhesion to the sidewalls of the hole pattern. The baking temperature should be between 70 and 180°C, preferably between 80 and 170°C, and the baking time should be between 10 and 300 seconds to remove excess shrinking agent and shrink the hole pattern. [Example]

[0300] Hereinafter, the present invention will be described in detail with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples.

[0301] The structures of the quenchers Q-1 to Q-16 used in the resist material are shown below. [Chemistry 159]

[0302] [Chemistry 160]

[0303] [Synthesis Example] Synthesis of base polymers (polymers P-1 to P-4) The monomers were combined and copolymerized in THF as a solvent. The mixture was then placed in methanol, and the precipitated solid was washed with hexane, separated, and dried to obtain base polymers (polymers P-1 to P-4) with the following compositions. The composition of the obtained base polymers was confirmed by 1H-NMR, and the Mw and Mw / Mn ratios were determined by GPC (solvent: THF, standard: polystyrene). [Chemistry 161]

[0304] [Examples 1-19, Comparative Examples 1 and 2] Preparation and Evaluation of Resist Materials (1) Preparation of resist materials The resist material was prepared by filtering the solution containing the components shown in Table 1 through a 0.2 μm filter. The resist materials of Examples 1 to 18 and Comparative Example 1 were positive-type, while the resist materials of Example 19 and Comparative Example 2 were negative-type.

[0305] In Table 1, the components are as follows. ･Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) DAA (Diacetone Alcohol) EL (ethyl lactate)

[0306] ･Acid generators: PAG-1, PAG-2 [Chemistry 162]

[0307] ･Comparative quencher: cQ-1 [Chemistry 163]

[0308] (2) EUV lithography evaluation The resist materials listed in Table 1 were spin-coated onto a 20 nm thick Si substrate coated with a Shin-Etsu Chemical Co., Ltd. silicon-containing spin-on hard mask SHB-A940 (silicon content: 43% by mass). The resulting resist film was pre-baked at 100°C for 60 seconds using a hot plate to produce a 60 nm thick resist film. The resist film was then exposed using an ASML EUV scanner NXE3400 (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, and a mask with a hole pattern of 44 nm pitch and +20% offset on the wafer). PEB was performed on a hot plate for 60 seconds at the temperature listed in Table 1, followed by development with a 2.38% by mass TMAH aqueous solution for 30 seconds. A hole pattern of 22 nm in size was obtained in Examples 1-18 and Comparative Example 1, while a dot pattern of 22 nm in size was obtained in Example 19 and Comparative Example 2. Using a Hitachi High-Tech Co., Ltd. length-measuring SEM (CG6300), we measured the exposure dose required to form a hole or dot size of 22 nm, and used this as the sensitivity. We also measured the dimensions of 50 holes or dots at this point, and calculated the CDU by multiplying the standard deviation (σ) by three times (3σ). The results are summarized in Table 1.

[0309] [Table 1] polymer (parts by mass) Acid generator (parts by mass) Quencher (parts by mass) organic solvents (parts by mass) PEB temperature (℃) Sensitivity (mJ / cm 2) CDU (nm) Example 1 P-1 (100) PAG-1 (24.7) Q-1 (7.34) PGMEA(3000) DAA(500) 85 31 3.2 Example 2 P-1 (100) PAG-2 (24.8) Q-2 (7.32) PGMEA(3000) DAA(500) 85 29 3.0 Example 3 P-1 (100) PAG-2 (24.8) Q-3 (7.88) PGMEA(3000) DAA(500) 85 30 2.8 Example 4 P-1 (100) PAG-2 (24.8) Q-4 (6.82) PGMEA(3000) DAA(500) 85 31 3.0 Example 5 P-1 (100) PAG-2 (24.8) Q-5 (7.38) PGMEA(3000) DAA(500) 85 27 3.0 Example 6 P-1 (100) PAG-2 (24.8) Q-6 (8.46) PGMEA(3000) DAA(500) 85 28 3.1 Example 7 P-1 (100) PAG-2 (24.8) Q-7 (7.90) PGMEA(3000) DAA(500) 85 28 2.8 Example 8 P-1 (100) PAG-2 (24.8) Q-8 (9.47) PGMEA(3000) DAA(500) 85 27 3.0 Example 9 P-1 (100) PAG-2 (24.8) Q-9 (8.18) PGMEA(3000) DAA(500) 85 31 3.1 Example 10 P-1 (100) PAG-2 (24.8) Q-10 (8.58) PGMEA(3000) DAA(500) 85 27 3.0 Example 11 P-1 (100) PAG-2 (24.8) Q-11 (10.40) PGMEA(3000) DAA(500) 85 30 3.1 Example 12 P-1 (100) PAG-2 (24.8) Q-12 (8.25) PGMEA(3000) DAA(500) 85 30 3.1 Example 13 P-1 (100) PAG-2 (24.8) Q-13 (8.24) PGMEA(3000) DAA(500) 85 29 3.0 Example 14 P-1 (100) PAG-2 (24.8) Q-14 (9.32) PGMEA(3000) DAA(500) 85 30 3.1 Example 15 P-1 (100) PAG-2 (24.8) Q-15 (8.24) PGMEA(3000) DAA(500) 85 32 3.0 Example 16 P-1 (100) PAG-2 (24.8) Q-16 (9.32) PGMEA(3000) DAA(500) 85 31 3.1 Example 17 P-2 (100) - Q-1 (7.34) PGMEA(3000) DAA(500) 90 31 2.7 Example 18 P-3 (100) - Q-1 (7.34) PGMEA(3000) DAA(500) 90 29 2.8 Example 19 P-4 (100) PAG-2 (24.8) Q-1 (7.34) PGMEA(3000) DAA(500) 115 35 3.7 Comparative Example 1 P-1 (100) PAG-2 (24.8) cQ-2 (4.46) PGMEA(3000) DAA(500) 85 34 4.2 Comparative Example 2 P-4 (100) PAG-2 (24.8) cQ-2 (4.46) PGMEA(3000) DAA(500) 115 33 5.3

[0310] The results shown in Table 1 indicate that the resist material of the present invention containing the coronium salt of the iodinated phenol compound has high sensitivity and improved CDU.

Claims

1. A resistive material comprising: a strontium salt of an iodinated phenol compound and an acid generating agent, wherein the strontium salt is represented by the following formula (1) and the acid generating agent is a strontium salt represented by the following formula (4-1); wherein m is 2 or 3; n is 0, 1, 2, or 3; however, 2≦m+n≦5; R1 is independently a halogen atom other than an iodine atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxygen group having 1 to 20 carbon atoms, a hydrocarbon carbonyl oxygen group having 2 to 20 carbon atoms, or a hydrocarbon sulfonyl oxygen group having 1 to 20 carbon atoms, and the hydrocarbon group, hydrocarbon oxygen group, hydrocarbon carbonyl oxygen group, and hydrocarbon sulfonyl oxygen group may also have at least one selected from halogen atoms and oxygen atoms; R2~R4 are each an independent hydrocarbon group with 1 to 20 carbon atoms, in which some or all of the hydrogen atoms are replaced by halogen atoms; furthermore, R2 and R3 can also bond to each other and form a ring together with the sulfur atoms they are bonded to; in formula (4-1), 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; XBI is an iodine atom or a bromine atom, and when p and / or q are 2 or more, they can be the same or different; L1 is a single bond, ether bond or ester bond, or a saturated hydrocarbon group with 1 to 6 carbon atoms that may contain ether bonds or ester bonds; L2 is a single bond or a divalent linking group with 1 to 20 carbon atoms when p is 1, and a (p+1) valent linking group with 1 to 20 carbon atoms when p is 2 or 3; R401 is a hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino group, or may contain a 1-20 carbon-numbered hydrocarbon group, a 1-20 carbon-numbered hydrocarbon oxy group, a 2-20 carbon-numbered hydrocarbon carbonyl group, a 2-20 carbon-numbered hydrocarbon oxycarbonyl group, a 2-20 carbon-numbered hydrocarbon carbonyl oxycarbonyl group, or a 1-20 carbon-numbered hydrocarbon sulfonyl oxy group, or -N(R401A)(R401B), -N(R401C)-C(=O)-R401D or -N(R401C)-C(=O)-O-R401D; R401 A and R401B are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms; R401C is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl oxygen group having 2 to 6 carbon atoms; R401D is an aliphatic hydrocarbon 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 also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl oxygen group having 2 to 6 carbon atoms; Rf1 to Rf4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, wherein at least one of them is a fluorine atom or a trifluoromethyl group; R402 to R404 are each independently a halogen atom or may also contain a hydrocarbon group having 1 to 20 carbon atoms with heteroatoms.

2. The inhibitor material as claimed in claim 1 further contains a base polymer.

3. The resist material as requested in item 2, wherein, The basic polymer contains at least one repeating unit selected from the repeating units represented by formula (a1) and formula (a2); wherein RA is independently a hydrogen atom or a methyl group; X1 is a single bond, a p-phenyl or a naphthyl group, or a linking group containing at least one of the following: an ester bond, an ether bond, and a lactone ring, and the p-phenyl, naphthyl, and linking group may also have at least one of the following: a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group with 1 to 8 carbons, and a saturated hydrocarbon carbonyl oxy group with 2 to 8 carbons; X2 is a single bond, an ester bond, or a amide bond; X3 is a single bond, an ether bond, or an ester bond; R11 and R12 are independently acid-labile groups; R13 is a hydroxyl group, a halogen atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbon group with 1 to 6 carbons; R14 is a single bond or an alkyldiyl group with 1 to 6 carbons, and a portion of the -CH2- of the alkyldiyl group may also be replaced by an ether bond or an ester bond; a is 1 or 2; b is an integer from 0 to 4; however, 1 ≦ a + b ≦ 5.

4. The inhibitor material as requested in item 3 is a chemically amplified positive inhibitor material.

5. The resist material as requested in item 2, wherein, The base polymer is free of acid-instable groups.

6. The inhibitor material in Request 5 is a chemically amplified negative inhibitor material.

7. The resist material as requested in item 2, wherein, The basic polymer contains at least one repeating unit selected from the following formulas (f1), (f2), (f3), (f4), and (f5); wherein RA is independently a hydrogen atom or a methyl group; Z1 is a single bond, an aliphatic alkyl group with 1 to 6 carbon atoms, an alkylphenyl group, an alkylnaphthyl group, or a group with 7 to 18 carbon atoms obtained by combining them, or -O-Z11-, -C(=O)-O-Z11-, or -C(=O)-NH-Z11-; Z11 is an aliphatic alkyl group with 1 to 6 carbon atoms, an alkylphenyl group, an alkylnaphthyl group, or a group with 7 to 18 carbon atoms obtained by combining them, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; Z2 is a single bond or an ester bond; Z3 is a single bond, -Z31-C(=O)-O-, -Z31-O-, or -Z31-OC(=O)-; Z31 is an aliphatic alkyl group with 1 to 12 carbon atoms, an alkyl phenyl group, or a group with 7 to 18 carbon atoms obtained by combining them, and may also contain a carbonyl group, ester bond, ether bond, iodine atom, or bromine atom; Z4 is methylene, 2,2,2-trifluoro-1,1-ethanediyl, or carbonyl; Z5 is a single bond, methylene, ethyl alkyl, alkyl phenyl, fluorinated alkyl phenyl, alkyl phenyl substituted with trifluoromethyl, -O-Z51-, -C(=O)-O-Z51-, or -C(=O)-NH-Z51-; Z51 is an aliphatic alkyl group with 1 to 6 carbon atoms, an alkyl phenyl group, fluorinated alkyl phenyl, or alkyl phenyl substituted with trifluoromethyl, and may also contain a carbonyl group, ester bond, ether bond, halogen atom, or hydroxyl group; Z6 is a single bond, an extended phenyl ring, an extended naphthyl ring, an ester bond, or an amide bond; Z7A is a single bond or a divalent organic group with 1 to 24 carbon atoms, and may also have at least one of the following: halogen atom, oxygen atom, nitrogen atom, and sulfur atom; Z7B is a monovalent organic group with 1 to 10 carbon atoms, and may also have at least one of the following: halogen atom, oxygen atom, nitrogen atom, and sulfur atom; Z8 is a single bond, an ether bond, an ester bond, a thioether bond, or an alkyl diel with 1 to 6 carbon atoms; Z9 is a trivalent organic group with 1 to 12 carbon atoms, and may also have at least one of the following: oxygen atom, nitrogen atom, and sulfur atom; R21 to R25 are each independently a halogen atom or may also contain a heteroatom and be a hydrocarbon group with 1 to 20 carbon atoms; furthermore, R23 and R24 may also be bonded to each other and form a ring together with the sulfur atoms they are bonded to; R26 are independently saturated hydrocarbon groups with 1 to 10 carbon atoms, aryl groups with 6 to 10 carbon atoms, fluorine atoms, iodine atoms, trifluoromethoxy, difluoromethoxy, cyano, or nitro groups; circle R is an aromatic hydrocarbon group with 6 to 10 carbon atoms and a (j+2) valence; j are independently integers from 0 to 5; M- is a non-nucleophilic relative ion.

8. The resist material in claim 1 further contains organic solvents.

9. The resist material in claim 1 further contains a surfactant.

10. A pattern forming method comprising the following steps: forming a resist film on a substrate using a resist material as claimed in any one of claims 1 to 9, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developer.

11. The pattern forming method as described in claim 10, wherein, The high-energy rays are KrF excimer laser light, ArF excimer laser light, electron beam, or extreme ultraviolet light with a wavelength of 3~15nm.