Positive resist material and pattern forming method

Abstract

The invention relates to a positive resist material and a pattern forming method. The present invention addresses the problem of providing: a positive resist material having superior sensitivity and resolution to known positive resist materials, small edge roughness and dimensional variation, and good pattern shape after exposure; and a pattern forming method. The positive resist material contains a base polymer containing a repeating unit (a) having a sulfonium salt structure of an iodinated phenol compound.

Description

Technical Field

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

[0002] With the high integration and high speed of LSIs, the miniaturization of pattern rules has been rapidly progressing. This is because of the progress of high-speed communication of 5G and the spread of artificial intelligence (AI), and high-performance devices for processing them have become necessary. Regarding the most advanced miniaturization technology, mass production of devices at the 5nm node by extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm has been carried out. In addition, discussions on the use of EUV lithography for devices at the next-generation 3nm node and the next-next-generation 2nm node have also been carried out, and IMEC in Belgium has announced the development of devices.

[0003] As miniaturization progresses, blurring of images due to acid diffusion has also become a problem. In order to ensure the resolution of fine patterns with a size of 45nm or less, it has been proposed that not only the improvement of dissolution contrast as previously claimed, but also the control of acid diffusion is important (Non-Patent Document 1). However, since chemically amplified resist materials use acid diffusion to improve sensitivity and contrast, if the post-exposure bake (PEB) temperature is lowered or the time is shortened to suppress acid diffusion to the limit, the sensitivity and contrast will be significantly reduced. If acid diffusion is suppressed to the limit, the sensitivity and contrast will be significantly reduced.

[0004] A trade-off relationship among sensitivity, resolution, and line width roughness (LWR) is exhibited. In order to improve the resolution, acid diffusion needs to be suppressed, but if the acid diffusion distance becomes shorter, the sensitivity will decrease.

[0005] It is effective to add an acid generator that generates a bulky acid to suppress acid diffusion. Thus, it has been proposed to contain a repeating unit derived from an onium salt having a polymerizable unsaturated bond in a polymer. At this time, the polymer also functions as an acid generator (polymer-bonded acid generator). Patent Document 1 proposes sulfonium salts and iodonium salts having polymerizable unsaturated bonds that generate specific sulfonic acids. Patent Document 2 proposes sulfonium salts in which sulfonic acid is directly bonded to the main chain.

[0006] In order to suppress acid diffusion, a resist material using a polymer-bonded quencher with a base polymer having a sulfonium salt structure of a weak acid having a polymerizable group with a pKa of -0.8 or more has been proposed (Patent Document 3). Here, examples of the weak acid include carboxylic acid, sulfonamide, phenol, hexafluorohydric alcohol, etc. Generally, the acidity of phenol and hexafluorohydric alcohol is too weak, the stability as a sulfonium salt is low, and it is also difficult to synthesize. Moreover, a resist material using a base polymer having a sulfonium salt structure of the aforementioned weak acid has a large swelling in an alkali developing solution, and there are problems such as deterioration of the size uniformity (CDU) of the contact hole pattern due to swelling during development and easy occurrence of pattern collapse after formation of the line and space pattern.

[0007] A resist material using a polymer-bonded quencher with a base polymer having a sulfonium salt structure of fluorinated phenol has been proposed (Patent Document 4). The sulfonium salt of phenol has the characteristic of small swelling, but due to insufficient absorption of EUV light, further improvement of performance is required.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-045311

[0011] [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-178317

[0012] [Patent Document 3] International Publication No. 2019 / 167737

[0013] [Patent Document 4] Japanese Patent Application Laid-Open No. 2022-115071

[0014] Non-Patent Documents

[0015] [Non-Patent Document 1] SPIE Vol.6520 65203L-1(2007) Summary of the Invention

[0016] [Problems to be Solved by the Invention]

[0017] In view of the above circumstances, the present invention aims to provide a positive resist material and a pattern forming method having sensitivity and resolution superior to those of known positive resist materials, small edge roughness and dimensional variation, and a good pattern shape after exposure.

[0018] [Means for Solving the Problems]

[0019] As a result of repeated and in-depth studies by the inventors of the present application in order to obtain a positive resist material with high resolution, small edge roughness, and small size variation in recent years, the following insights were obtained: that is, in order to obtain this positive resist material, it is necessary to shorten the acid diffusion distance to the limit and make the acid diffusion distance uniform at the molecular level. By using a polymer containing a repeating unit having a sulfonium salt structure of an iodinated phenol compound as the base polymer, due to the large size of the iodine atom, the acid diffusion becomes very small, and due to the high absorption of the iodine atom, the physical contrast is improved, and due to the high effect of the iodine atom in improving the acidity of the phenolic group, the dissolution contrast is improved. These three effects make it effective as a base polymer for a chemically amplified positive resist material with small LWR and good CDU.

[0020] Furthermore, the following insights were obtained and the present invention was completed: In order to improve the dissolution contrast, a repeating unit in which a hydrogen atom of a carboxyl group or a phenolic hydroxyl group is substituted with an acid-labile group is introduced, whereby a positive resist material with high sensitivity, a large increase in the alkali dissolution rate contrast before and after exposure, a high effect of suppressing acid diffusion, high resolution, a good pattern shape after exposure, small LWR, and good CDU can be obtained, which is particularly suitable as a fine pattern forming material for manufacturing ultra-large-scale integrated circuits or photomasks.

[0021] That is, the present invention provides the following positive resist material and pattern forming method.

[0022] 1. A positive resist material, comprising:

[0023] A base polymer containing a repeating unit a having a sulfonium salt structure of an iodinated phenol compound.

[0024] 2. The positive resist material according to 1., wherein the repeating unit a is represented by the following formula (a).

[0025] [Chemical formula 1]

[0026]

[0027] In the formula, R A is a hydrogen atom or a methyl group.

[0028] X 1 is a single bond, an ester bond, an ether bond, a phenylene group or a naphthylene group.

[0029] X 2 is a single bond, a saturated alkylene group having 1 to 12 carbon atoms or a phenylene group, and the saturated alkylene group may also contain at least one selected from an ether bond, an ester bond, an amide bond, a lactone ring and a sultone ring.

[0030] X 3 is a single bond, an ester bond or an ether bond.

[0031] R 1 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom other than an iodine atom, a nitro group or a cyano group.

[0032] R 2 to R 4 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a hetero atom. Further, R 2 and R 3 may also be bonded to each other and together with the sulfur atom to which they are bonded form a ring.

[0033] m is an integer of 1 to 4. n is an integer of 0 to 3. However, 1 ≤ m + n ≤ 4.

[0034] 3. The positive resist material according to 1. or 2., wherein the base polymer contains at least one selected from the repeating unit b1 in which the hydrogen atom of the carboxyl group is substituted with an acid-labile group and the repeating unit b2 in which the hydrogen atom of the phenolic hydroxyl group is substituted with an acid-labile group.

[0035] 4. The positive resist material according to 3., wherein the repeating unit b1 is represented by the following formula (b1), and the repeating unit b2 is represented by the following formula (b2).

[0036] [Chemical formula 2]

[0037]

[0038] In the formula, R A are each independently a hydrogen atom or a methyl group.

[0039] Y 1 is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms containing at least one selected from an ester bond, an ether bond and a lactone ring, and the phenylene group, the naphthylene group and the linking group may also have at least one selected from a halogen atom, a hydroxyl group, a saturated hydrocarbon group oxy group having 1 to 8 carbon atoms and a saturated hydrocarbon group carbonyl oxy group having 2 to 8 carbon atoms.

[0040] Y 2 is a single bond, an ester bond or an amide bond.

[0041] Y 3 is a single bond, an ether bond or an ester bond.

[0042] R 11 and R 12 are each independently an acid-labile group.

[0043] 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, a saturated hydrocarbon group oxy group having 1 to 6 carbon atoms or a saturated hydrocarbon group carbonyl oxy group having 2 to 7 carbon atoms.

[0044] R 14is a single bond or an alkylene group having 1 to 6 carbon atoms, and -CH of the alkylene group 2 - part may also be substituted with an ether bond or an ester bond.

[0045] a is 1 or 2. b is an integer of 0 to 4. However, 1 ≤ a + b ≤ 5.

[0046] 5. The positive resist material according to 3. or 4., wherein the base polymer contains a repeating unit c having an adhesion group selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonate bond, a cyano group, an amide bond, -O-C(=O)-S- and -O-C(=O)-NH-.

[0047] 6. The positive resist material according to any one of 3. to 5., wherein the base polymer contains at least one selected from a repeating unit represented by the following formula (d1), a repeating unit represented by the following formula (d2), a repeating unit represented by the following formula (d3), a repeating unit represented by the following formula (d4), and a repeating unit represented by the following formula (d5).

[0048] [Chemical formula 3]

[0049]

[0050] In the formula, R A are each independently a hydrogen atom or a methyl group.

[0051] 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 obtained by combining them, or -O-Z 11 -, -C(=O)-O-Z 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 obtained by combining them, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group.

[0052] Z 2 is a single bond or an ester bond.

[0053] Z 3 is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -O-C(=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 obtained by combining them, and may also contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom.

[0054] Z4 is methylene, 2,2,2-trifluoro-1,1-ethanediyl or carbonyl.

[0055] Z 5 is a single bond, methylene, ethylene, phenylene, fluorophenylene, phenylene substituted with trifluoromethyl, -O-Z 51 -, -C(=O)-O-Z 51 - or -C(=O)-NH-Z 51 -. Z 51 is an aliphatic alkylene group having 1 to 6 carbon atoms, phenylene, fluorophenylene or phenylene substituted with trifluoromethyl, and may also contain a carbonyl group, an ester bond, an ether bond, a halogen atom or a hydroxyl group.

[0056] Z 6 is a single bond, phenylene, naphthylene ring, ester bond or amide bond.

[0057] Z 7A is a single bond or a divalent organic group having 1 to 24 carbon atoms, and may also have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom and a sulfur atom.

[0058] Z 7B is a monovalent organic group having 1 to 10 carbon atoms, and may also have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom and a sulfur atom.

[0059] 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.

[0060] Z 9 is a trivalent organic group having 1 to 12 carbon atoms, and may also have at least one selected from an oxygen atom, a nitrogen atom and a sulfur atom.

[0061] R 21 ~R 25 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. Further, 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.

[0062] R 26 are 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.

[0063] Circular R is a (j + 2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms.

[0064] j are each independently an integer from 0 to 5.

[0065] M - is a non-nucleophilic counterion.

[0066] 7. The positive resist material according to any one of 3. to 6. further contains an acid generator that generates a strong acid.

[0067] 8. The positive resist material according to any one of 3. to 7. further contains an organic solvent.

[0068] 9. The positive resist material according to any one of 3. to 8. further contains a quencher.

[0069] 10. The positive resist material according to any one of 3. to 9. further contains a surfactant.

[0070] 11. A pattern forming method includes the following steps:

[0071] Forming a resist film on a substrate using the positive resist material according to any one of 1. to 10.,

[0072] Exposing the aforementioned resist film to high-energy rays, and

[0073] Developing the aforementioned exposed resist film using a developer.

[0074] 12. In the pattern forming method according to 11., the high-energy rays are i-rays, KrF excimer laser, ArF excimer laser, electron beam (EB), or EUV with a wavelength of 3 to 15 nm.

[0075] [Advantages of the Invention]

[0076] The positive resist material of the present invention can improve the decomposition efficiency of the acid generator, so it has a high effect of suppressing the diffusion of acid. It is highly sensitive and has high resolution. The pattern shape, edge roughness, and size variation after exposure are small and good. Therefore, due to these excellent characteristics, its practicality is extremely high. In particular, it is very effective as a fine pattern forming material for manufacturing ultra-large-scale integrated circuits or for photomasks using EB drawing, and as a pattern forming material for EB or EUV lithography. The positive resist material of the present invention can be applied, for example, not only to lithography in semiconductor circuit formation, but also to the formation of mask circuit patterns, micro-machinery, and thin-film head circuit formation. Detailed Embodiments

[0077] [Base Polymer]

[0078] The resist material of the present invention is characterized by containing:

[0079] A base polymer containing a repeating unit a having a sulfonium salt structure of an iodinated phenol compound.

[0080] The repeating unit a is preferably represented by the following formula (a).

[0081] [Chemical Formula 4]

[0082]

[0083] In formula (a), R A is a hydrogen atom or a methyl group.

[0084] In formula (a), X 1 is a single bond, an ester bond, an ether bond, a phenylene group or a naphthylene group.

[0085] In formula (a), X 2 is a single bond, a saturated alkylene group having 1 to 12 carbon atoms or a phenylene group, and the saturated alkylene group may also contain at least one selected from an ether bond, an ester bond, an amide bond, a lactone ring and a sultone ring. The saturated alkylene group represented by X 2 may be linear, branched or cyclic, and specific examples thereof include: methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,2-diyl, butane-1,3-diyl, butane-1,4-diyl, butane-2,2-diyl, butane-2,3-diyl, 2-methylpropane-1,3-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 and other alkanediyl groups having 1 to 12 carbon atoms; cyclopentanediyl, cyclohexanediyl, norbornanediyl, adamantanediyl and other cyclic saturated alkylene groups having 3 to 12 carbon atoms; groups obtained by combining them, etc.

[0086] In formula (a), X 3 is a single bond, an ester bond or an ether bond.

[0087] In formula (a), R 1 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom other than an iodine atom, a nitro group or a cyano group. Specific examples of the alkyl group include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl.

[0088] In formula (a), m is an integer of 1 to 4. n is an integer of 0 to 3. However, 1 ≤ m + n ≤ 4. m is preferably 2, 3 or 4, more preferably 2 or 3. n is preferably 0, 1 or 2, more preferably 0 or 1.

[0089] Specific examples of the anion of the monomer providing the repeating unit a are as shown below, but are not limited thereto. In addition, in the following formula, R A is the same as the above.

[0090] [Chemical Formula 5]

[0091]

[0092] [Chemical Formula 6]

[0093]

[0094] [Chemical Formula 7]

[0095]

[0096] [Chemical Formula 8]

[0097]

[0098] [Chemical Formula 9]

[0099]

[0100] [Chemical Formula 10]

[0101]

[0102] [Chemical Formula 11]

[0103]

[0104] [Chemical Formula 12]

[0105]

[0106] In formula (a), R 2 ~R 4 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom.

[0107] R 2 ~R 4 Specific examples of the halogen atom represented include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.

[0108] R 2 ~R 4The hydrocarbon group having 1 to 20 carbon atoms represented 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, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, icosyl; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, adamantyl; alkenyl groups having 2 to 20 carbon atoms such as vinyl, propenyl, butenyl, hexenyl; alkynyl groups having 2 to 20 carbon atoms such as ethynyl, propynyl, butynyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms such as cyclohexenyl, norbornenyl; aryl groups having 6 to 20 carbon atoms such as phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl; aralkyl groups having 7 to 20 carbon atoms such as benzyl, phenethyl; groups obtained by combining them, etc.

[0109] Further, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and part of the -CH 2 - of the aforementioned hydrocarbon group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc., and as a result, it may also contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a mercapto group, a pentafluorothio 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)-O-C(=O)-), a haloalkyl group, etc.

[0110] Further, R 2 and R 3 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the aforementioned ring is preferably one having the following structure.

[0111] [Chemical formula 13]

[0112]

[0113] In the formula, the dotted line is a bond to the atom of R 4 .

[0114] Specific examples of the sulfonium cation of the repeating unit a include those shown below, but are not limited thereto.

[0115] [Chemical formula 14]

[0116]

[0117] [Chemical 15]

[0118]

[0119] [Chemical 16]

[0120]

[0121] [Chemical 17]

[0122]

[0123] [Chemical 18]

[0124]

[0125] [Chemical 19]

[0126]

[0127] [Chemical 20]

[0128]

[0129] [Chemical 21]

[0130]

[0131] [Chemical 22]

[0132]

[0133] [Chemical 23]

[0134]

[0135] [Chemical 24]

[0136]

[0137] [Chemical 25]

[0138]

[0139] [Chemical 26]

[0140]

[0141] [Chemical 27]

[0142]

[0143] [Chemical 28]

[0144]

[0145] [Chemical 29]

[0146]

[0147] [Chemical Formula 30]

[0148]

[0149] [Chemical Formula 31]

[0150]

[0151] [Chemical Formula 32]

[0152]

[0153] [Chemical Formula 33]

[0154]

[0155] [Chemical Formula 34]

[0156]

[0157] [Chemical Formula 35]

[0158]

[0159] [Chemical Formula 36]

[0160]

[0161] [Chemical Formula 37]

[0162]

[0163] [Chemical Formula 38]

[0164]

[0165] [Chemical Formula 39]

[0166]

[0167] [Chemical Formula 40]

[0168]

[0169] [Chemical Formula 41]

[0170]

[0171] [Chemical Formula 42]

[0172]

[0173] [Chemical Formula 43]

[0174]

[0175] [Chemical formula 44]

[0176]

[0177] [Chemical formula 45]

[0178]

[0179] [Chemical formula 46]

[0180]

[0181] [Chemical formula 47]

[0182]

[0183] [Chemical formula 48]

[0184]

[0185] By photolysis, the sulfonium cation decomposes and becomes an iodinated phenol group bonded to the polymer. The iodinated phenol group has the characteristic of less swelling in an alkaline developer than weak acid groups such as carboxylic acid, sulfonamide, and hexafluorohydric alcohol. Due to this characteristic, the CDU of the contact hole pattern is improved, and the stress applied to the pattern during spin drying for drying after pure water rinsing of the line and space pattern is reduced, and pattern collapse after pattern formation can be reduced.

[0186] The aforementioned repeating unit a is a quencher having a sulfonium salt structure of an iodinated phenol compound and is a quencher-bonded polymer. The quencher-bonded polymer has a high effect of suppressing acid diffusion and has excellent resolution as described above. At the same time, since the repeating unit a has an iodine atom, the quenchers do not aggregate due to the repulsive force of the negatively charged iodine atoms, and the acid diffusion distance is made uniform. In addition, the absorption of iodine atoms generates secondary electrons during exposure and promotes the decomposition of the acid generator, thereby achieving high sensitivity. Therefore, high sensitivity, high resolution, low LWR, and improvement of CDU can be achieved simultaneously.

[0187] In the aforementioned base polymer, in order to improve the dissolution contrast, it may also contain a repeating unit in which a hydrogen atom of a carboxyl group is replaced by an acid-labile group (hereinafter also referred to as repeating unit b1), and / or a repeating unit in which a hydrogen atom of a phenolic hydroxyl group is replaced by an acid-labile group (hereinafter also referred to as repeating unit b2).

[0188] Specific examples of the repeating units b1 and b2 can be respectively those represented by the following formulas (b1) and (b2).

[0189] [Chemical formula 49]

[0190]

[0191] In formulas (b1) and (b2), R A is independently a hydrogen atom or a methyl group. Y 1 is a single bond, a phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms containing at least one selected from an ester bond, an ether bond, and a lactone ring, 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 group oxy group having 1 to 8 carbon atoms, and a saturated hydrocarbon group carbonyl oxy group having 2 to 8 carbon atoms. Y 2 is a single bond, an ester bond, or an amide bond. Y 3 is a single bond, an ether bond, or an ester bond. R 11 and R 12 are independently acid-labile groups. 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, a saturated hydrocarbon group oxy group having 1 to 6 carbon atoms, or a saturated hydrocarbon group carbonyl oxy group having 2 to 7 carbon atoms. R 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and a part of -CH 2 - of the alkanediyl group may also be substituted with an ether bond or an ester bond. a is 1 or 2. b is an integer of 0 to 4. However, 1 ≤ a + b ≤ 5.

[0192] Specific examples of the monomer providing the repeating unit b1 are as follows, but are not limited thereto. In addition, in the following formulas, R A and R 11 are the same as described above.

[0193] [Chemical formula 50]

[0194]

[0195] [Chemical formula 51]

[0196]

[0197] [Chemical formula 52]

[0198]

[0199] Specific examples of the monomer providing the repeating unit b2 are as follows, but are not limited thereto. In addition, in the following formulas, R A and R 12 are the same as described above.

[0200] [Chemical formula 53]

[0201]

[0202] R 11 or R 12There are various choices for the acid-labile groups represented, and examples thereof include those represented by the following formulas (AL-1) to (AL-3).

[0203] [Chemical formula 54]

[0204]

[0205] In the formula, the dotted line represents an atomic bond.

[0206] In formula (AL-1), c is an integer from 0 to 6. R L1 is a tertiary hydrocarbon group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, a trihydrocarbylsilyl group in which each hydrocarbyl 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). In addition, the tertiary hydrocarbon group means a group obtained by detaching a hydrogen atom from the tertiary carbon atom of the hydrocarbon.

[0207] R L1 The represented tertiary hydrocarbon group can be saturated or unsaturated, branched or cyclic. Specific examples thereof include: tert-butyl, tert-pentyl, 1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, 2-methyl-2-adamantyl, etc. Specific examples of the aforementioned trihydrocarbylsilyl group include: trimethylsilyl, triethylsilyl, dimethyl-tert-butylsilyl, etc. The aforementioned saturated hydrocarbon group containing a carbonyl group, an ether bond or an ester bond can be linear, branched or cyclic, preferably cyclic, and specific examples thereof include: 3-oxocyclohexyl, 4-methyl-2-oxooxane-4-yl, 5-methyl-2-oxooxolane-5-yl, 2-tetrahydropyranyl, 2-tetrahydrofuranyl, etc.

[0208] Specific examples of the acid-labile group represented by formula (AL-1) include: tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-pentyloxycarbonyl, tert-pentyloxycarbonylmethyl, 1,1-diethylpropyloxycarbonyl, 1,1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyl-oxycarbonyl, 1-ethyl-2-cyclopentenyl-oxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, 2-tetrahydrofuranyloxycarbonylmethyl, etc.

[0209] 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.

[0210] [Chemical formula 55]

[0211]

[0212] In the formula, the dashed line represents an atomic bond.

[0213] In Formulas (AL-1)-1 to (AL-1)-10, c is the same as described above. R L8 are each independently a saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. R L9 is a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. R L10 is a saturated hydrocarbon group having 2 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. The aforementioned saturated hydrocarbon group may be linear, branched, or cyclic.

[0214] In Formula (AL-2), R L2 and R L3 are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The aforementioned saturated hydrocarbon group may be linear, branched, or cyclic, and specific examples thereof include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, n-octyl, etc.

[0215] In Formula (AL-2), R L4 is a hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, which may also contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples of the aforementioned hydrocarbon group include: saturated hydrocarbon groups having 1 to 18 carbon atoms, etc., and a part of the hydrogen atoms thereof may also be substituted with a hydroxyl group, an alkoxy group, an oxo group, an amino group, an alkylamino group, etc. Specific examples of such substituted saturated hydrocarbon groups include those shown below, etc.

[0216] [Chemical Formula 56]

[0217]

[0218] In the formula, the dashed line represents an atomic bond.

[0219] R L2 and R L3 , R L2 and R L4 , or R L3 and R L4 may also be bonded to each other and together with the carbon atoms to which they are bonded form a ring or together with the carbon atoms and oxygen atoms form a ring. In this case, R L2 and R L3 , R L2 and R L4 , or R L3 and R L4 are each independently an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The carbon number of the ring formed by bonding them is preferably 3 to 10, more preferably 4 to 10.

[0220] Among the acid-labile groups represented by formula (AL-2), specific examples of linear or branched ones include those represented by the following formulas (AL-2)-1 to (AL-2)-69, but are not limited thereto. In the following formulas, the dotted line represents an atomic bond.

[0221] [Chemical formula 57]

[0222]

[0223] [Chemical formula 58]

[0224]

[0225] [Chemical formula 59]

[0226]

[0227] [Chemical formula 60]

[0228]

[0229] Among the acid-labile groups represented by formula (AL-2), specific examples of cyclic ones include tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, 2-methyltetrahydropyran-2-yl, and the like.

[0230] Furthermore, the acid-labile group may include a group represented by the following formula (AL-2a) or (AL-2b). By using the aforementioned acid-labile group, the base polymer can also be crosslinked intermolecularly or intramolecularly.

[0231] [Chemical formula 61]

[0232]

[0233] In the formula, the dotted line represents an atomic bond.

[0234] 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 aforementioned saturated hydrocarbon group may be linear, branched, or cyclic. Also, R L11 and R L12 may also be bonded to each other and together with the carbon atom 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 are each independently a saturated subhydrocarbon group having 1 to 10 carbon atoms. The aforementioned saturated subhydrocarbon group may be linear, branched, or cyclic. d and e are each independently an integer of 0 to 10, preferably an integer of 0 to 5, and f is an integer of 1 to 7, preferably an integer of 1 to 3.

[0235] In formula (AL-2a) or (AL-2b), L A is an aliphatic saturated hydrocarbon group with 1 to 50 carbon atoms and (f + 1) valences, an alicyclic saturated hydrocarbon group with 3 to 50 carbon atoms and (f + 1) valences, an aromatic hydrocarbon group with 6 to 50 carbon atoms and (f + 1) valences, or a heterocyclic group with 3 to 50 carbon atoms and (f + 1) valences. Also, a part of -CH 2 - in these groups may also be substituted with a heteroatom-containing group, and a part of the hydrogen atoms in these groups may also be substituted with a hydroxyl group, a carboxyl group, an acyl group, or a fluorine atom. L A is preferably a saturated hydrocarbon group such as a saturated alkylene group with 1 to 20 carbon atoms, a trivalent saturated hydrocarbon group, a tetravalent saturated hydrocarbon group, an arylene group with 6 to 30 carbon atoms, etc. The aforementioned saturated hydrocarbon group may be linear, branched, or cyclic. L B is -C(=O)-O-, -NH-C(=O)-O-, or -NH-C(=O)-NH-.

[0236] Specific examples of the crosslinked acetal group represented by formula (AL-2a) or (AL-2b) include groups represented by the following formula (AL-2)-70 to (AL-2)-77, etc.

[0237] [Chemical formula 62]

[0238]

[0239] In the formula, the dotted line is an atomic bond.

[0240] In formula (AL-3), R L5 is a hydrogen atom or a hydrocarbon group with 1 to 20 carbon atoms, and the hydrocarbon group may also contain heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, and a fluorine atom. R L6 and R L7 are each independently a hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, and a fluorine atom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include an alkyl group with 1 to 20 carbon atoms, a cyclic saturated hydrocarbon group with 3 to 20 carbon atoms, an alkenyl group with 2 to 20 carbon atoms, a cyclic unsaturated hydrocarbon group with 3 to 20 carbon atoms, an aryl group with 6 to 10 carbon atoms, etc. Also, R L5 and R L6 , R L5 and R L7 , or R L6 and R L7 may also be bonded to each other and together with the carbon atoms to which they are bonded form an alicyclic ring with 3 to 20 carbon atoms.

[0241] Specific examples of the group represented by formula (AL-3) include: tert-butyl, 1,1-diethylpropyl, 1-ethylnorbornanyl, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-isopropylcyclopentyl, 1-methylcyclohexyl, 2-(2-methyl)adamantyl, 2-(2-ethyl)adamantyl, tert-pentyl, and the like.

[0242] Furthermore, the groups represented by the following formulas (AL-3)-1 to (AL-3)-22 can also be cited as the group represented by formula (AL-3).

[0243] [Chemical formula 63]

[0244]

[0245] In the formula, the dashed line represents an atomic bond.

[0246] In formulas (AL-3)-1 to (AL-3)-22, R L14 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. R L15 and R L17 are independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms. R L16 is an aryl group having 6 to 20 carbon atoms. The aforementioned saturated hydrocarbon group can be linear, branched, or cyclic. Furthermore, the aforementioned aryl group is preferably a phenyl group or the like. R L18 is a fluorine atom, an iodine atom, a nitro group, or a trifluoromethyl group. R L19 are 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 hydrocarbon oxy group having 1 to 8 carbon atoms. g is an integer of 1 to 5.

[0247] In addition, acid-labile groups include the groups represented by the following formula (AL-3)-23 or (AL-3)-24. By using the aforementioned acid-labile groups, the polymer can also be crosslinked intramolecularly or intermolecularly.

[0248] [Chemical formula 64]

[0249]

[0250] In the formula, the dashed line represents an atomic bond.

[0251] In formulas (AL-3)-23 and (AL-3)-24, R L14 is the same as the aforementioned one. R L20 is a (h + 1)-valent saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms or a (h + 1)-valent arylene group having 6 to 20 carbon atoms, and may also contain heteroatoms such as an oxygen atom, a sulfur atom, and a nitrogen atom. The aforementioned saturated or unsaturated hydrocarbon group can be linear, branched, or cyclic. h is an integer of 1 to 3.

[0252] In addition to these acid-labile groups, acid-labile groups containing aromatic groups described in Japanese Patent Publication No. 5565293, Japanese Patent Publication No. 5434983, Japanese Patent Publication No. 5407941, Japanese Patent Publication No. 5655756, and Japanese Patent Publication No. 5655755 can also be used.

[0253] The aforementioned base polymer may also contain a repeating unit c having a sealing group selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonate bond, a cyano group, an amide bond, -O-C(=O)-S-, and -O-C(=O)-NH-.

[0254] Specific examples of the monomer providing the repeating unit c are as shown below, but are not limited thereto. In addition, in the following formula, R A is the same as described above.

[0255] [Chemical formula 65]

[0256]

[0257] [Chemical formula 66]

[0258]

[0259] [Chemical formula 67]

[0260]

[0261] [Chemical formula 68]

[0262]

[0263] [Chemical formula 69]

[0264]

[0265] [Chemical formula 70]

[0266]

[0267] [Chemical formula 71]

[0268]

[0269] [Chemical formula 72]

[0270]

[0271] [Chemical formula 73]

[0272]

[0273] [Chemical formula 74]

[0274]

[0275] [Chemical Formula 75]

[0276]

[0277] [Chemical Formula 76]

[0278]

[0279] The aforementioned base polymer may also contain at least one selected from the repeating units represented by the following formula (d1) (hereinafter also referred to as repeating unit d1), the repeating units represented by the following formula (d2) (hereinafter also referred to as repeating unit d2), the repeating units represented by the following formula (d3) (hereinafter also referred to as repeating unit d3), the repeating units represented by the following formula (d4) (hereinafter also referred to as repeating unit d4), and the repeating units represented by the following formula (d5) (hereinafter also referred to as repeating unit d5).

[0280] [Chemical Formula 77]

[0281]

[0282] In formulas (d1) to (d5), R A is independently a hydrogen atom or a methyl group respectively.

[0283] In formulas (d1) to (d3), Z 1 is a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, a group having 7 to 18 carbon atoms obtained by combining them, or -O-Z 11 -, -C(=O)-O-Z 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 obtained by combining them, 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 -O-C(=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 obtained by combining them, 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, 2,2,2-trifluoro-1,1-ethanediyl, or a carbonyl group. Z 5 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -O-Z 51-, -C(=O)-O-Z 51 - or -C(=O)-NH-Z 51 -. Z 51 is 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. Further, Z 1 , Z 11 , Z 31 and Z 51 The aliphatic alkylene group represented may be saturated or unsaturated, and may be linear, branched or cyclic.

[0284] In formulas (d4) and (d5), Z 6 is a single bond, a phenylene group, a naphthylene ring, an ester bond or an amide bond.

[0285] In formula (d4), Z 7A is a single bond or a divalent organic group having 1 to 24 carbon atoms, and may also have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom and a sulfur atom.

[0286] Z 7AThe divalent organic group represented can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples thereof include C1-C24 alkylene groups in which part or all of the hydrogen atoms are substituted with iodine atoms or bromine atoms. Specific examples of the C1-C24 alkylene groups 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 other alkanediyls; cyclopentanediyl, methylcyclopentanediyl, dimethylcyclopentanediyl, trimethylcyclopentanediyl, tetramethylcyclopentanediyl, cyclohexanediyl, methylcyclohexanediyl, dimethylcyclohexanediyl, trimethylcyclohexanediyl, tetramethylcyclohexanediyl, norbornanediyl, adamantanediyl and other cyclic saturated alkylene groups; phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, tert-butylnaphthylene, biphenyldiyl, methylbiphenyldiyl, dimethylbiphenyldiyl and other arylene groups; groups obtained by combining them, etc. Also, Z 7A part or all of the hydrogen atoms of which may also be substituted with a group containing at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom, and Z 7A part of the -CH 2 - may also 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, it may contain a hydroxyl group, an ester bond, an ether bond, an amide bond, a urethane bond, a urea bond, etc.

[0287] In formula (d5), Z 7B is a monovalent organic group having 1 to 10 carbon atoms and may also have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom.

[0288] Z 7BThe monovalent organic group represented can be saturated or unsaturated, and can be any of linear, branched, or cyclic. Specific examples thereof include hydrocarbon groups having 1 to 10 carbon atoms in which part or all of the hydrogen atoms are substituted with iodine atoms or bromine atoms. Specific examples of the hydrocarbon groups 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, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, 3-pentyl, tert-pentyl, neopentyl, n-hexyl, n-octyl, n-nonyl, 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, ethylcyclohexyl; alkenyl groups having 2 to 10 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, butenyl, pentenyl, hexenyl, heptenyl, nonenyl, decenyl; alkynyl groups having 2 to 10 carbon atoms such as ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonynyl, decynyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 10 carbon atoms such as cyclopentenyl, cyclohexenyl, methylcyclopentenyl, methylcyclohexenyl, ethylcyclopentenyl, ethylcyclohexenyl, norbornenyl; aryl groups having 6 to 10 carbon atoms such as phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl; aralkyl groups having 7 to 10 carbon atoms such as benzyl, phenethyl, phenylpropyl, phenylbutyl; groups obtained by combining them, etc. Also, Z 7B Part or all of the hydrogen atoms of can also be substituted with a group containing at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom, and Z 7B -CH 2 - of can also 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, it may contain a hydroxyl group, an ester bond, an ether bond, an amide bond, a urethane bond, a urea bond, etc.

[0289] In formulas (d4) and (d5), 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.

[0290] In formula (d5), Z 9 is a trivalent organic group having 1 to 12 carbon atoms and may also have at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom. Z 9The trivalent organic group represented may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof may include groups obtained by further removing one hydrogen atom from a C1-C12 alkylene group. Specific examples of the C1-C12 alkylene group may include those having 1 to 12 carbon atoms among the C1-C24 alkylene groups described above. Also, Z 9 A part or all of the hydrogen atoms of may also be substituted with a group containing at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom, and Z 9 A part of -CH 2 - may also 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, it may contain a hydroxyl group, an ester bond, an ether bond, an amide bond, a urethane bond, a urea bond, etc.

[0291] In formulas (d1) to (d5), R 21 ~R 25 are each independently a halogen atom or a C1-C20 hydrocarbon group which may contain a heteroatom. Specific examples of the halogen atom may include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof may include the same examples as those exemplified as the hydrocarbon groups represented by R 2 ~R 4 in the description of formula (a). Also, a part or all of the hydrogen atoms of the hydrocarbon group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and a part of -CH 2 - of the hydrocarbon group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, it may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate ester bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-O-C(=O)-), a haloalkyl group, etc. In addition, 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. At this time, specific examples of the ring may include the same examples as those exemplified as the rings that can be formed when R 2 and R 3 are bonded to each other and form a ring together with the sulfur atom to which they are bonded.

[0292] In formulas (d4) and (d5), R 26 are each independently a C1-C10 saturated hydrocarbon group, a C6-C10 aryl group, a fluorine atom, an iodine atom, a trifluoromethoxy group, a difluoromethoxy group, a cyano group, or a nitro group.

[0293] In formulas (d4) and (d5), the circular R is a (j + 2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms. Specific examples of the aforementioned (j + 2)-valent aromatic hydrocarbon group include groups obtained by detaching (j + 2) hydrogen atoms from aromatic hydrocarbons such as benzene and naphthalene.

[0294] In formulas (d4) and (d5), j is independently an integer from 0 to 5.

[0295] In formula (d1), M - is a non-nucleophilic counter ion. Specific examples of the aforementioned non-nucleophilic counter ion 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; methylation ions such as tris(trifluoromethylsulfonyl)methylation ion and tris(perfluoroethylsulfonyl)methylation ion.

[0296] More specific examples of the aforementioned non-nucleophilic counter ion include: sulfonate ions in which the α-position is substituted with a fluorine atom represented by the following formula (d1-1), sulfonate ions in which the α-position is substituted with a fluorine atom and the β-position is substituted with a trifluoromethyl group represented by the following formula (d1-2), and the like.

[0297] [Chemical formula 78]

[0298]

[0299] In formula (d1-1), R 31 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may also contain at least one selected from an ether bond, an ester bond, a carbonyl group, a lactone ring, and a fluorine atom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof may include the same examples as those of the hydrocarbon group represented by R fa1 shown in formula (1A') described later.

[0300] In formula (d1-2), R 32 is a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a hydrocarbon group carbonyl having 2 to 30 carbon atoms, and the hydrocarbon group and the hydrocarbon group carbonyl may also contain at least one selected from an ether bond, an ester bond, a carbonyl group, and a lactone ring. The hydrocarbon moieties of the aforementioned hydrocarbon group and hydrocarbon group carbonyl may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof may include the same examples as those of the hydrocarbon group represented by R fa1 shown in formula (1A') described later.

[0301] Specific examples of the cations of the monomers providing the repeating unit d1 are as follows, but are not limited thereto. Further, in the following formula, R A is the same as described above.

[0302] Specific examples of the ions are as follows, but are not limited thereto. Further, in the following formula, R A is the same as described above.

[0303] [Chemical formula 79]

[0304]

[0305] Specific examples of the cations of the repeating units d2 to d5 can be the same examples as those exemplified as the cations of the repeating unit a.

[0306] Specific examples of the anions of the monomers providing the repeating unit d2 are as follows, but are not limited thereto. Further, in the following formula, R A is the same as described above.

[0307] [Chemical formula 80]

[0308]

[0309] [Chemical formula 81]

[0310]

[0311] [Chemical formula 82]

[0312]

[0313] [Chemical formula 83]

[0314]

[0315] [Chemical formula 84]

[0316]

[0317] [Chemical formula 85]

[0318]

[0319] [Chemical formula 86]

[0320]

[0321] [Chemical formula 87]

[0322]

[0323] [Chemical formula 88]

[0324]

[0325] [Chemical formula 89]

[0326]

[0327] [Chemical formula 90]

[0328]

[0329] [Chemical formula 91]

[0330]

[0331] [Chemical formula 92]

[0332]

[0333] [Chemical formula 93]

[0334]

[0335] [Chemical formula 94]

[0336]

[0337] Specific examples of the anions of the monomers providing the repeating unit d3 are as follows, but are not limited thereto. In addition, in the following formula, R A is the same as described above.

[0338] [Chemical formula 95]

[0339]

[0340] Specific examples of the anions of the monomers providing the repeating unit d4 or d5 are as follows, but are not limited thereto. In addition, in the following formula, R A and X BI are the same as described above.

[0341] [Chemical formula 96]

[0342]

[0343] [Chemical formula 97]

[0344]

[0345] [Chemical formula 98]

[0346]

[0347] [Chemical formula 99]

[0348]

[0349] [Chemical 100]

[0350]

[0351] [Chemical 101]

[0352]

[0353] [Chemical 102]

[0354]

[0355] [Chemical 103]

[0356]

[0357] [Chemical 104]

[0358]

[0359] [Chemical 105]

[0360]

[0361] [Chemical 106]

[0362]

[0363] [Chemical 107]

[0364]

[0365] [Chemical 108]

[0366]

[0367] [Chemical 109]

[0368]

[0369] [Chemical 110]

[0370]

[0371] [Chemical 111]

[0372]

[0373] [Chemical 112]

[0374]

[0375] [Chemical 113]

[0376]

[0377] [Chemical 114]

[0378]

[0379] [Chemical 115]

[0380]

[0381] [Chemical 116]

[0382]

[0383] [Chemical 117]

[0384]

[0385] [Chemical 118]

[0386]

[0387] [Chemical 119]

[0388]

[0389] [Chemical 120]

[0390]

[0391] The repeating units d1 to d5 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 the blur 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 d1 to d5 (i.e., a polymer-bonded acid generator), the blending of the additive acid generator described later can be omitted.

[0392] The aforementioned base polymer may also contain a repeating unit e that does not contain an amino group but contains an iodine atom. Specific examples of the monomer that provides the repeating unit e are as shown below, but are not limited thereto. In addition, in the following formula, R A is the same as the aforementioned.

[0393] [Chemical 121]

[0394]

[0395] [Chemical 122]

[0396]

[0397] [Chemical 123]

[0398]

[0399] The aforementioned base polymer may also contain repeating unit f other than the aforementioned repeating units. Specific examples of repeating unit f may include those derived from styrene, vinylnaphthalene, indene, acenaphthene, coumarin, coumarone, etc.

[0400] In the aforementioned base polymer, the content ratios of repeating units a, b1, b2, c, d1, d2, d3, d4, d5, e, and f are preferably 0 < a < 1.0, 0 ≤ b1 ≤ 0.9, 0 ≤ b2 ≤ 0.9, 0 ≤ b1 + b2 ≤ 0.9, 0 ≤ c ≤ 0.9, 0 ≤ d1 ≤ 0.5, 0 ≤ d2 ≤ 0.5, 0 ≤ d3 ≤ 0.5, 0 ≤ d4 ≤ 0.5, 0 ≤ d5 ≤ 0.5, 0 ≤ d1 + d2 + d3 + d4 + d5 ≤ 0.5, 0 ≤ e ≤ 0.5, and 0 ≤ f ≤ 0.5. More preferably, they are 0.001 ≤ a ≤ 0.8, 0 ≤ b1 ≤ 0.8, 0 ≤ b2 ≤ 0.8, 0 ≤ b1 + b2 ≤ 0.8, 0 ≤ c ≤ 0.8, 0 ≤ d1 ≤ 0.4, 0 ≤ d2 ≤ 0.4, 0 ≤ d3 ≤ 0.4, 0 ≤ d4 ≤ 0.4, 0 ≤ d5 ≤ 0.4, 0 ≤ d1 + d2 + d3 + d4 + d5 ≤ 0.4, 0 ≤ e ≤ 0.4, and 0 ≤ f ≤ 0.4. Even more preferably, they are 0.01 ≤ a ≤ 0.7, 0 ≤ b1 ≤ 0.7, 0 ≤ b2 ≤ 0.7, 0 ≤ b1 + b2 ≤ 0.7, 0 ≤ c ≤ 0.7, 0 ≤ d1 ≤ 0.3, 0 ≤ d2 ≤ 0.3, 0 ≤ d3 ≤ 0.3, 0 ≤ d4 ≤ 0.3, 0 ≤ d5 ≤ 0.3, 0 ≤ d1 + d2 + d3 + d4 + d5 ≤ 0.3, 0 ≤ e ≤ 0.3, and 0 ≤ f ≤ 0.3. However, a + b1 + b2 + c + d1 + d2 + d3 + d4 + d5 + e + f = 1.0.

[0401] Examples of the method for synthesizing the aforementioned base polymer include, for example, a method in which monomers providing the aforementioned repeating units are added with a radical polymerization initiator and heated in an organic solvent to carry out polymerization.

[0402] 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 their mixed solvents, etc. 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 the polymerization is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, and more preferably 5 to 20 hours.

[0403] When copolymerizing a hydroxyl group-containing monomer, the hydroxyl group can be substituted with an acetal group such as ethoxyethoxy that is easily deprotected by an acid in advance during the polymerization, and deprotection can be carried out using a weak acid and water after the polymerization. It is also possible to substitute with an acetyl group, a formyl group, a trimethylacetyl group, etc. in advance and carry out base hydrolysis after the polymerization.

[0404] 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.

[0405] As the base for base hydrolysis, ammonia water, triethylamine, etc. can be used. 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.

[0406] The polystyrene-equivalent weight-average molecular weight (Mw) of the aforementioned base polymer 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. If Mw is within the aforementioned range, the heat resistance of the resist film and the solubility in an alkali developing solution are good.

[0407] Also, in the aforementioned base polymer, when the molecular weight distribution (Mw / Mn) is wide, since there are low-molecular-weight and high-molecular-weight polymers, there is a concern that foreign substances may be observed in the pattern and the shape of the pattern may deteriorate after exposure. As the pattern rule is miniaturized, the influence of Mw and Mw / Mn also easily becomes large. Therefore, in order to obtain a positive resist material that can be ideally used for fine pattern sizes, the Mw / Mn of the aforementioned base polymer is preferably 1.0 to 2.0, and a narrow dispersion of 1.0 to 1.5 is particularly excellent.

[0408] In order to obtain a narrow-dispersion polymer, not only ordinary radical polymerization but also living radical polymerization can be used. Specific examples of living radical polymerization include: Nitroxide-Mediated radical Polymerization (NMP) using a nitroxide radical, Atom Transfer Radical Polymerization (ATRP), Reversible Addition-Fragmentation chain Transfer (RAFT) polymerization, etc.

[0409] The aforementioned base polymer may also contain two or more polymers having different composition ratios, Mw, and Mw / Mn. Also, a polymer containing repeating unit a and a polymer containing repeating units b1 and / or b2 without containing repeating unit a can be blended.

[0410] [Acid generator]

[0411] The positive resist material of the present invention may also contain an acid generator that generates a strong acid (hereinafter also referred to as an additive acid generator). Here, the strong acid means a compound having an acidity sufficient to cause a deprotection reaction of the acid-labile group of the base polymer.

[0412] Examples of the acid generator include compounds that are sensitive to actinic rays or radiation and generate an acid (photoacid generators). Any compound that generates an acid upon irradiation with high-energy rays may be used as the photoacid generator, and those that generate sulfonic acid, imidic acid, or methide acid are preferred. Ideal photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate type acid generators. Specific examples of the photoacid generator can be found in paragraphs

[0122] to

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

[0413] Furthermore, sulfonium salts represented by the following formula (1-1) and iodonium salts represented by the following formula (1-2) can be preferably used as the photoacid generator.

[0414] [Chemical Formula 124]

[0415]

[0416] In formulas (1-1) and (1-2), R 101 ~R 105 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms that may contain a hetero atom. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. The hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof are the same as those exemplified in the description of formula (a) as the hydrocarbon groups represented by R 2 ~R 4 . Furthermore, a part or all of the hydrogen atoms of the hydrocarbon group may be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and a part of -CH 2 - of the hydrocarbon group may be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, it may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group, etc. In addition, R 101 and R 102 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. At this time, specific examples of the ring are the same as those exemplified in the description of formula (a) as the rings that can be formed when R 2 and R 3 are bonded to each other and form a ring together with the sulfur atom to which they are bonded.

[0417] Specific examples of the cation of the sulfonium salt represented by formula (1-1) may include and illustrate the same examples as those of the cation as the repeating unit a.

[0418] Specific examples of the cation of the iodonium salt represented by formula (1-2) are as follows, but are not limited thereto.

[0419] [Chemical formula 125]

[0420]

[0421] [Chemical formula 126]

[0422]

[0423] In formulas (1-1) and (1-2), Xa - is an anion selected from the following formulas (1A) to (1D).

[0424] [Chemical formula 127]

[0425]

[0426] In formula (1A), R fa is a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof may include and illustrate the same examples as those of the hydrocarbon group represented by R fa1 in formula (1A') described below.

[0427] The anion represented by formula (1A) is preferably the one represented by the following formula (1A').

[0428] [Chemical formula 128]

[0429]

[0430] In formula (1A'), R HF is a hydrogen atom or a trifluoromethyl group, and is preferably a trifluoromethyl group. R fa1 is a hydrocarbon group having 1 to 38 carbon atoms which may contain a heteroatom. The aforementioned heteroatom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, etc., and more preferably an oxygen atom. From the viewpoint of obtaining high resolution in fine pattern formation, the aforementioned hydrocarbon group is particularly preferably one having 6 to 30 carbon atoms.

[0431] R fa1The represented hydrocarbon group can be saturated or unsaturated, and can be any of linear, branched, or cyclic. Specific examples thereof that 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, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, icosyl, etc., with those having 6 to 30 carbon atoms being particularly preferred; cyclic saturated hydrocarbon groups having 3 to 38 carbon atoms such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, dicyclohexylmethyl, etc.; unsaturated aliphatic hydrocarbon groups having 2 to 38 carbon atoms such as allyl, 3-cyclohexenyl, etc.; aryl groups having 6 to 38 carbon atoms such as phenyl, 1-naphthyl, 2-naphthyl, etc.; aralkyl groups having 7 to 38 carbon atoms such as benzyl, diphenylmethyl, etc.; groups obtained by combining them, etc.

[0432] Further, a part or all of the hydrogen atoms of the aforementioned hydrocarbon group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and a part of -CH 2 - of the aforementioned hydrocarbon group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc., and as a result, it may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-O-C(=O)-), a haloalkyl group, etc. Specific examples of the heteroatom-containing hydrocarbon group include: tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 3-oxocyclohexyl, etc.

[0433] Regarding the synthesis of the sulfonium salt containing the anion represented by formula (1A’), refer to Japanese Patent Application Laid-Open No. 2007-145797, Japanese Patent Application Laid-Open No. 2008-106045, Japanese Patent Application Laid-Open No. 2009-7327, Japanese Patent Application Laid-Open No. 2009-258695, etc. Further, the sulfonium salts described in Japanese Patent Application Laid-Open No. 2010-215608, Japanese Patent Application Laid-Open No. 2012-41320, Japanese Patent Application Laid-Open No. 2012-106986, Japanese Patent Application Laid-Open No. 2012-153644, etc. can also be appropriately used.

[0434] Specific examples of the anion represented by formula (1A) can be listed and exemplified as those similar to the anion represented by formula (1A) in Japanese Patent Application Laid-Open No. 2018-197853.

[0435] In formula (1B), R fb1 and Rfb2 Each independently is a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may also contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, or cyclic. Specific examples thereof may be listed and exemplified as the hydrocarbon group represented by R in formula (1A’). fa1 The same examples as those of the hydrocarbon group represented by R fb1 and R fb2 are preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. Also, R fb1 and R fb2 may also be bonded to each other and together with the group to which they are bonded (-CF 2 -SO 2 -N - -SO 2 -CF 2 -) form a ring. In this case, the group obtained by bonding R fb1 and R fb2 to each other is preferably a fluoroethylene or fluoropropylene group.

[0436] In formula (1C), R fc1 , R fc2 and R fc3 each independently is a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may also contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, or cyclic. Specific examples thereof may be listed and exemplified as the hydrocarbon group represented by R in formula (1A’). fa1 The same examples as those of the hydrocarbon group represented by R fc1 , R fc2 and R fc3 are preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. Also, R fc1 and R fc2 may also be bonded to each other and together with the group to which they are bonded (-CF 2 -SO 2 -C - -SO 2 -CF 2 -) form a ring. In this case, the group obtained by bonding R fc1 and R fc2 to each other is preferably a fluoroethylene or fluoropropylene group.

[0437] In formula (1D), R fd is a hydrocarbon group having 1 to 40 carbon atoms which may also contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, or cyclic. Specific examples thereof may be listed and exemplified as the hydrocarbon group represented by R in formula (1A’). fa1 The same examples as those of the hydrocarbon group represented by R

[0438] For the synthesis of sulfonium salts containing the anion represented by formula (1D), refer to Japanese Patent Application Laid-Open No. 2010-215608 and Japanese Patent Application Laid-Open No. 2014-133723.

[0439] Specific examples of the anion represented by formula (1D) can be enumerated and exemplified as those similar to the anion represented by formula (1D) in Japanese Patent Application Laid-Open No. 2018-197853.

[0440] In addition, the photoacid generator containing the anion represented by formula (1D) does not have a fluorine atom at the α-position of the sulfo group, but has two trifluoromethyl groups at the β-position, so it has an acidity sufficient to cleave the acid-labile group in the base polymer. Therefore, it can be used as a photoacid generator.

[0441] A photoacid generator represented by the following formula (2) can also be preferably used.

[0442] [Chemical Formula 129]

[0443]

[0444] In formula (2), R 201 and R 202 are each independently a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom. R 203 is an alkylene group having 1 to 30 carbon atoms which may contain a heteroatom. Also, any two of R 201 , R 202 and R 203 may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. At this time, specific examples of the aforementioned ring can be enumerated as those similar to the rings that can be formed by bonding R 2 and R 3 and forming a ring together with the sulfur atom to which they are bonded as exemplified in the description of formula (a).

[0445] R 201 and R 202 represent hydrocarbon groups that may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6Cyclic saturated hydrocarbon groups having 3 to 30 carbon atoms such as decyl and adamantyl; aryl groups having 6 to 30 carbon atoms such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, anthryl, etc.; groups obtained by combining them, etc. Further, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of -CH 2 - of the aforementioned hydrocarbon group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, it may also 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)-O-C(=O)-), a haloalkyl group, etc.

[0446] R 203 The alkylene group represented may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof 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, etc., alkandiyl groups having 1 to 30 carbon atoms; cyclopentanediyl, cyclohexanediyl, norbornanediyl, adamantanediyl, etc., cyclic saturated alkylene groups having 3 to 30 carbon atoms; phenylene, methylenephenyl, ethylenephenyl, n-propylenephenyl, isopropylenephenyl, n-butylenephenyl, isobutylenephenyl, sec-butylenephenyl, tert-butylenephenyl, naphthylene, methylenenaphthylene, ethylenenaphthylene, n-propylenaphthylene, isopropylenaphthylene, n-butylenaphthylene, isobutylenaphthylene, sec-butylenaphthylene, tert-butylenaphthylene, etc., arylene groups having 6 to 30 carbon atoms; groups obtained by combining them, etc. Further, part or all of the hydrogen atoms of the aforementioned alkylene group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of -CH 2 - of the aforementioned alkylene group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, it may also 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)-O-C(=O)-), a haloalkyl group, etc. The aforementioned heteroatom is preferably an oxygen atom.

[0447] In formula (2), L C is a single bond, an ether bond, or an alkylene group having 1 to 20 carbon atoms which may also contain a heteroatom. The aforementioned alkylene group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. Specific examples thereof may be listed and exemplified as the alkylene group represented by R 203 the same examples as those of the alkylene group represented.

[0448] In formula (2), X A , X B , X C and X D are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. However, at least one of X A , X B , X C and X D is a fluorine atom or a trifluoromethyl group.

[0449] In formula (2), k is an integer from 0 to 3.

[0450] The photoacid generator represented by formula (2) is preferably the one represented by the following formula (2’).

[0451] [Chemical formula 130]

[0452]

[0453] In formula (2’), L C is the same as the aforementioned one. X E is a hydrogen atom or a trifluoromethyl group, and is preferably a trifluoromethyl group. R 301 , R 302 and R 303 are each independently a hydrogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. Specific examples thereof may be listed and exemplified as the hydrocarbon group represented by R fa1 in formula (1A’). x and y are each independently an integer from 0 to 5, and z is an integer from 0 to 4.

[0454] Specific examples of the photoacid generator represented by formula (2) may be listed and are the same as those exemplified as the photoacid generator represented by formula (2) in Japanese Patent Laid-Open No. 2017-026980.

[0455] Among the foregoing photoacid generators, those containing an anion represented by the formula (1A') or (1D) are particularly desirable because they have low acid diffusion and excellent solubility in solvents. Further, those represented by the formula (2') are particularly desirable because they have extremely low acid diffusion. As the foregoing photoacid generators, sulfonium salts or iodonium salts containing an anion having an aromatic ring substituted with an iodine atom or a bromine atom can also be used. Specific examples of such salts include those represented by the following formula (3-1) or (3-2).

[0456] [Chemical formula 131]

[0457]

[0458] In the formulas (3-1) and (3-2), p is an integer satisfying 1 ≤ p ≤ 3. q and r are integers satisfying 1 ≤ q ≤ 5, 0 ≤ r ≤ 3, and 1 ≤ q + r ≤ 5. q is preferably an integer satisfying 1 ≤ q ≤ 3, more preferably 2 or 3. r is preferably an integer satisfying 0 ≤ r ≤ 2.

[0459] In the formulas (3-1) and (3-2), X BI is an iodine atom or a bromine atom, and when p and / or q is 2 or more, they may be the same or different from each other.

[0460] In the formulas (3-1) and (3-2), L 1 is a single bond, an ether bond, an ester bond, or a saturated C1-C6 alkylene group which may contain an ether bond or an ester bond. The foregoing saturated alkylene group may be linear, branched, or cyclic.

[0461] In the formulas (3-1) and (3-2), L 2 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.

[0462] In the formulas (3-1) and (3-2), R 401 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, or an amino group, or a C1-C20 hydrocarbon group, a C1-C20 hydrocarbon oxy group, a C2-C20 hydrocarbon carbonyl group, a C2-C20 hydrocarbon oxycarbonyl group, a C2-C20 hydrocarbon carbonyloxy group, or a C1-C20 hydrocarbon sulfonyloxy group which may 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)-O-R 401D . R 401A and R 401BEach independently is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 401C 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 group oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon group carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon group carbonyl oxy group having 2 to 6 carbon atoms. R 401D 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 group oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon group carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon group carbonyl oxy 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 group, hydrocarbon group oxy group, hydrocarbon group carbonyl group, hydrocarbon group oxycarbonyl group, hydrocarbon group carbonyl oxy group, and hydrocarbon group sulfonyl oxy group 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.

[0463] Among them, R 401 is preferably a hydroxyl group, -N(R 401C )-C(=O)-R 401D , -N(R 401C )-C(=O)-O-R 401D , a fluorine atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group, etc.

[0464] In formulas (3-1) and (3-2), Rf 1 ~Rf 4 each independently is a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. Also, Rf 1 and Rf 2 may also combine to form a carbonyl group. It is particularly preferable that both Rf 3 and Rf 4 are fluorine atoms.

[0465] In formulas (3-1) and (3-2), R 402 ~R 406 each independently is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms that may also contain a heteroatom. Specific examples of the aforementioned halogen atom include: a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. 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 in the description of formula (a) as the hydrocarbon groups represented by R 2 ~R 4 . Also, a part 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 sulfonium salt, and the -CH 2A part of the "-" may also be replaced by an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond or a sulfonate bond. In addition, R 402 and R 403 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. At this time, specific examples of the aforementioned ring may include the same examples as those exemplified in the description of formula (a) as R 2 and R 3 which are bonded to each other and form a ring together with the sulfur atom to which they are bonded.

[0466] Specific examples of the cation of the sulfonium salt represented by formula (3-1) may include the same examples as those exemplified as the cation of the repeating unit a. Also, specific examples of the cation of the oxonium salt represented by formula (3-2) may include the same examples as those exemplified as the cation of the oxonium salt represented by formula (1-2).

[0467] Specific examples of the anion of the onium salt represented by formula (3-1) or (3-2) are as shown below, but are not limited thereto. In addition, in the following formula, X BI is the same as the aforementioned one.

[0468] [Chemical formula 132]

[0469]

[0470] [Chemical formula 133]

[0471]

[0472] [Chemical formula 134]

[0473]

[0474] [Chemical formula 135]

[0475]

[0476] [Chemical formula 136]

[0477]

[0478] [Chemical formula 137]

[0479]

[0480] [Chemical formula 138]

[0481]

[0482] [Chemical formula 139]

[0483]

[0484] [Chemical formula 140]

[0485]

[0486] [Chemical Formula 141]

[0487]

[0488] [Chemical Formula 142]

[0489]

[0490] [Chemical Formula 143]

[0491]

[0492] [Chemical Formula 144]

[0493]

[0494] [Chemical Formula 145]

[0495]

[0496] [Chemical Formula 146]

[0497]

[0498] [Chemical Formula 147]

[0499]

[0500] [Chemical Formula 148]

[0501]

[0502] [Chemical Formula 149]

[0503]

[0504] [Chemical Formula 150]

[0505]

[0506] [Chemical Formula 151]

[0507]

[0508] [Chemical Formula 152]

[0509]

[0510] [Chemical Formula 153]

[0511]

[0512] [Chemical Formula 154]

[0513]

[0514] The aforementioned photoacid generator can also be a sulfonium salt or an iodonium salt of fluorobenzenesulfonic acid bonded to iodobenzoic acid represented by the following formula (3-3) or (3-4).

[0515] [Chemical 155]

[0516]

[0517] In formula (3-3) and (3-4), s is an integer from 1 to 5. t is an integer from 0 to 3. u is an integer from 1 to 4.

[0518] In formula (3-3) and (3-4), 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 with 1 to 20 carbon atoms, a saturated hydrocarbon group oxy with 1 to 20 carbon atoms, or a saturated hydrocarbon group carbonyloxy with 2 to 20 carbon atoms that 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)-O-R 411B , and R 411A is a hydrogen atom or a saturated hydrocarbon group with 1 to 6 carbon atoms. R 411B is an aliphatic hydrocarbon group with 1 to 16 carbon atoms, an aryl group with 6 to 14 carbon atoms, or an aralkyl group with 7 to 15 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon group oxy with 1 to 6 carbon atoms, a saturated hydrocarbon group carbonyl with 2 to 6 carbon atoms, or a saturated hydrocarbon group carbonyloxy with 2 to 6 carbon atoms.

[0519] In formula (3-3) and (3-4), L 3 is a single bond or a divalent linking group with 1 to 20 carbon atoms, and the linking group may also contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0520] In formula (3-3) and (3-4), Rf 11 is a fluorine atom or a trifluoromethyl group.

[0521] In formula (3-3) and (3-4), R 412 to R 416 are each independently a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may also contain a heteroatom. Specific examples of the aforementioned halogen atom include: a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be any of linear, branched, or cyclic. Specific examples thereof can be listed as those exemplified in the description of formula (a) as R 2 to R 4Examples similar to the represented hydrocarbon group. Also, part 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 sulfonium salt, and part of -CH 2 - of the aforementioned hydrocarbon group may also be substituted with an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond, or a sulfonate bond. In addition, R 402 and R 403 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. At this time, specific examples of the aforementioned ring may include the same examples as those of the ring that can be formed by bonding to R 2 and R 3 and the sulfur atom to which they are bonded as exemplified in the description of formula (a).

[0522] Specific examples of the cation of the sulfonium salt represented by formula (3-3) may include the same examples as those of the cation exemplified as the repeating unit a. Specific examples of the cation of the oxonium salt represented by formula (3-4) may include the same examples as those of the cation of the oxonium salt represented by formula (1-2).

[0523] Specific examples of the anion of the onium salt represented by formula (3-3) or (3-4) are as follows, but are not limited thereto.

[0524] [Chemical formula 156]

[0525]

[0526] [Chemical formula 157]

[0527]

[0528] [Chemical formula 158]

[0529]

[0530] [Chemical formula 159]

[0531]

[0532] [Chemical formula 160]

[0533]

[0534] When the positive resist material of the present invention contains the aforementioned additive acid generator, its content is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass, based on 100 parts by mass of the base polymer. The aforementioned additive acid generator may be used alone or in combination of two or more. In the positive resist material of the present invention, the aforementioned base polymer can function as a chemically amplified positive resist material by containing any one of the repeating units d1 to d5 and / or by containing an additive acid generator.

[0535] [Organic solvent]

[0536] The positive resist material of the present invention may also contain an organic solvent. If the aforementioned organic solvent can dissolve the aforementioned components and the following components, there is no particular limitation. Specific examples of the aforementioned organic solvent include: ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, 2-heptanone, etc. described in paragraphs

[0144] to

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

[0537] In the positive 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 in combination of two or more.

[0538] [Other components]

[0539] In the positive resist material of the present invention, in addition to containing the aforementioned components, it may also contain a surfactant, a dissolution inhibitor, a quencher, a water repellency improver, acetylene alcohols, etc.

[0540] Specific examples of the aforementioned surfactant include those described in paragraphs

[0165] to

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

[0541] By blending a dissolution inhibitor in the positive resist material of the present invention, the dissolution rate difference between the exposed portion and the unexposed portion can be further enlarged, and the resolution can be further improved. Specific examples of the aforementioned dissolution inhibitor include: a compound in which the hydrogen atom of the phenolic hydroxyl group in a compound having a molecular weight of preferably 100 to 1000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups in the molecule is replaced by an acid-labile group in a proportion of 0 to 100 mol% as a whole, or a compound in which the hydrogen atom of the carboxyl group in a compound containing a carboxyl group in the molecule is replaced by an acid-labile group in a proportion of preferably 50 to 100 mol% on average as a whole. Specific examples include: compounds obtained by replacing the hydrogen atoms of the hydroxyl group and carboxyl group of bisphenol A, triphenol, phenolphthalein, cresol novolak resin, naphthalene carboxylic acid, adamantane carboxylic acid, cholic acid, etc. with acid-labile groups, for example, those described in paragraphs

[0155] to

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

[0542] When the positive resist material of the present invention 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 inhibitor can be used alone or in combination of two or more.

[0543] A quencher (hereinafter referred to as an additive quencher) can also be blended in the resist material of the present invention. Specific examples of the aforementioned additive quencher include known types of basic compounds. Specific examples of the known basic compounds include: primary, secondary or tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, urethanes, etc. Particularly preferably, 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, a sulfonate bond, or compounds having a urethane group described in Japanese Patent No. 3790649 are particularly preferred. By adding such a basic compound, for example, the diffusion rate of acid in the resist film can be further suppressed, or the shape can be corrected.

[0544] Furthermore, the aforementioned additive quencher includes onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids and carboxylic acids in which the α-position is not fluorinated, as described in Japanese Patent Application Laid-Open No. 2008-158339. Sulfonic acids, imidic acids, or methylated acids in which the α-position is fluorinated are necessary for deprotecting the acid-labile group of the carboxylic acid ester, and by salt exchange with the onium salt in which the α-position is not fluorinated, sulfonic acids or carboxylic acids in which the α-position is not fluorinated are released. Sulfonic acids and carboxylic acids in which the α-position is not fluorinated do not cause a deprotection reaction, so they function as quenchers.

[0545] Other examples of the aforementioned additive quencher include the polymer quencher described in Japanese Patent Application Laid-Open No. 2008-239918. It improves the rectangularity of the resist pattern by aligning on the surface of the resist film. The polymer quencher also has the effect of preventing pattern film loss and pattern doming when using a protective film for immersion exposure.

[0546] When the positive resist material of the present invention contains the aforementioned additive quencher, its content is preferably 0 to 5 parts by mass, more preferably 0 to 4 parts by mass, based on 100 parts by mass of the base polymer. The aforementioned additive quencher can be used alone or in combination of two or more.

[0547] The aforementioned water repellency improver is one that improves the water repellency of the resist film surface and can be used in immersion lithography without using a topcoat. The aforementioned water repellency improver is preferably a polymer containing a fluorinated alkyl group, a polymer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues with a specific structure, etc., and more preferably those exemplified in Japanese Patent Application Laid-Open No. 2007-297590, Japanese Patent Application Laid-Open No. 2008-111103, etc. The aforementioned water repellency improver must be soluble in an alkali developer and an organic solvent developer. The aforementioned specific water repellency improver having 1,1,1,3,3,3-hexafluoro-2-propanol residues has good solubility in the developer. Regarding the water repellency improver, a polymer containing repeating units of amino group and amine salt has a high effect of preventing evaporation of acid during PEB and preventing poor opening of the hole pattern after development. When the positive 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, based on 100 parts by mass of the base polymer. The aforementioned water repellency improver can be used alone or in combination of two or more.

[0548] 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 positive resist material of the present invention contains the aforementioned acetylene alcohols, its content is preferably 0 to 5 parts by mass, based on 100 parts by mass of the base polymer. The aforementioned acetylene alcohols can be used alone or in combination of two or more.

[0549] [Pattern formation method]

[0550] When the positive 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 the pattern formation method can be a method including the following steps:

[0551] Forming a resist film on a substrate using the aforementioned positive resist material,

[0552] The foregoing resist film is exposed to high-energy rays, and

[0553] The foregoing exposed resist film is developed using a developer.

[0554] First, the positive resist material of the present invention is applied by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or blade coating so that the coating thickness becomes 0.01 to 2 μm on a substrate for integrated circuit manufacturing (Si, SiO 2 , SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflection film, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi 2 , SiO 2 , etc.). It is prebaked on a hot plate 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.

[0555] Then, the foregoing resist film is exposed to high-energy rays. Specific examples of the foregoing high-energy rays include: ultraviolet rays, far ultraviolet rays, EB, EUV with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer lasers, γ-rays, synchrotron radiation, etc. When the foregoing high-energy rays use ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer lasers, γ-rays, synchrotron radiation, etc., directly or using a mask for forming a target pattern, and the exposure amount is preferably about 1 to 200 mJ / cm 2 and more preferably about 10 to 100 mJ / cm 2 for irradiation. When the high-energy rays use EB, the exposure amount is preferably about 0.1 to 100 μC / cm 2 and more preferably about 0.5 to 50 μC / cm 2 for direct writing or using a mask for forming a target pattern. In addition, the positive resist material of the present invention is particularly suitable for fine patterning by i-rays with a wavelength of 365 nm, KrF excimer lasers, ArF excimer lasers, EB, EUV, X-rays, soft X-rays, γ-rays, synchrotron radiation in high-energy rays, and is particularly suitable for fine patterning by EB or EUV.

[0556] After exposure, PEB can also be performed on a hot plate or in an oven at 50 to 150 °C for 10 seconds to 30 minutes, and more preferably at 60 to 120 °C for 30 seconds to 20 minutes.

[0557] After exposure or PEB, by using a developer containing an aqueous alkali solution such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), etc., which should be 0.1 to 10% by mass, and more preferably 2 to 5% by mass, and using common methods such as the dip method, puddle method, spray method, etc., develop the exposed resist film for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, so that the irradiated part dissolves in the developer, while the unexposed part does not dissolve, and form a desired positive pattern on the substrate.

[0558] It is also possible to use the aforementioned positive resist material and develop it with an organic solvent to obtain a negative pattern. Specific examples of the developer used at this time 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, butenyl 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, phenethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in combination of two or more.

[0559] Rinse is carried out at the end of development. The rinsing liquid should be a solvent that is miscible with the developer and does not dissolve the resist film. Such solvents can ideally be alcohols with 3 to 10 carbon atoms, ether compounds with 8 to 12 carbon atoms, alkanes, alkenes, alkynes, aromatic solvents with 6 to 12 carbon atoms, etc.

[0560] Specific examples of the aforementioned alcohols with 3 to 10 carbon atoms include: n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentanol, neopentanol, 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.

[0561] Specific examples of the ether compound having 8 to 12 carbon atoms include: di-n-butyl ether, diisobutyl ether, di(sec-butyl) ether, di-n-pentyl ether, diisopentyl ether, di(sec-pentyl) ether, di(tert-pentyl) ether, di-n-hexyl ether, and the like.

[0562] Specific examples of the alkane having 6 to 12 carbon atoms include: hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, and the like. Specific examples of the alkene having 6 to 12 carbon atoms include: hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, and the like. Specific examples of the alkyne having 6 to 12 carbon atoms include: hexyne, heptyne, octyne, and the like.

[0563] Specific examples of the aromatic solvent include: toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, mesitylene, and the like.

[0564] By performing rinsing, the collapse of the resist pattern and the occurrence of defects can be reduced. Also, rinsing is not necessary, and by not performing rinsing, the amount of solvent used can be reduced.

[0565] The developed hole pattern and groove pattern can also be shrunk by using heat flow, RELACS technology, or DSA technology. A shrinkage agent is applied to the hole pattern, and due to the diffusion of the acid catalyst from the resist film during baking, crosslinking of the shrinkage agent is caused on the surface of the resist film, and the shrinkage agent adheres to the sidewalls of the hole pattern. The baking temperature is preferably 70 to 180 °C, more preferably 80 to 170 °C, and the baking time is preferably 10 to 300 seconds to remove the excess shrinkage agent and shrink the hole pattern.

[0566] Examples

[0567] Hereinafter, the present invention will be specifically described by way of synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0568] [1] Synthesis of Monomers

[0569] [Synthesis Examples 1-1 to 1-7, Comparative Synthesis Example 1-1]

[0570] The following monomers M-1 to M-7 and comparative monomer cM-1 were obtained by ion exchange of a sulfonium chloride salt with an iodinated phenol compound or a carboxylic acid compound having a polymerizable double bond.

[0571] [Chemical Formula 161]

[0572]

[0573] [2] Synthesis of Base Polymer

[0574] The monomers PM-1 to PM-3 used in the synthesis of the base polymer are as described below. Also, the Mw of the polymer was determined as a polystyrene equivalent value by GPC using THF as the solvent.

[0575] [Chemical formula 162]

[0576]

[0577] [Synthesis Example 2-1] Synthesis of Polymer P-1

[0578] 4.1 g of monomer M-1, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 5.4 g of 4-hydroxystyrene, and 40 g of THF as a solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen purging were repeated 3 times. After warming to room temperature, 1.2 g of AIBN as a polymerization initiator was added, and the temperature was raised to 60 °C and allowed to react for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain Polymer P-1. The composition of Polymer P-1 was confirmed by 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[0579] [Chemical formula 163]

[0580]

[0581] [Synthesis Example 2-2] Synthesis of Polymer P-2

[0582] 4.7 g of monomer M-2, 8.8 g of 1-methyl-1-cyclohexyl methacrylate, 4.2 g of 4-hydroxystyrene, 9.0 g of monomer PM-1, and 40 g of THF as a solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen purging were repeated 3 times. After warming to room temperature, 1.2 g of AIBN as a polymerization initiator was added, and the temperature was raised to 60 °C and allowed to react for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain Polymer P-2. The composition of Polymer P-2 was confirmed by 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[0583] [Chemical formula 164]

[0584]

[0585] [Synthesis Example 2-3] Synthesis of Polymer P-3

[0586] 4.4 g of monomer M-3, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 9.0 g of monomer PM-1, and 40 g of THF as a solvent were added to a 2 L flask. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen purging were repeated 3 times. After warming to room temperature, 1.2 g of AIBN as a polymerization initiator was added, and the temperature was raised to 60°C and the mixture was allowed to react for 15 hours. The reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was separated by filtration. The obtained white solid was dried under reduced pressure at 60°C to obtain Polymer P-3. The composition of Polymer P-3 was confirmed by 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[0587] [Chemical Formula 165]

[0588]

[0589] [Synthesis Example 2-4] Synthesis of Polymer P-4

[0590] 5.0 g of monomer M-4, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 9.0 g of monomer PM-1, and 40 g of THF as a solvent were added to a 2 L flask. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen purging were repeated 3 times. After warming to room temperature, 1.2 g of AIBN as a polymerization initiator was added, and the temperature was raised to 60°C and the mixture was allowed to react for 15 hours. The reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was separated by filtration. The obtained white solid was dried under reduced pressure at 60°C to obtain Polymer P-4. The composition of Polymer P-4 was confirmed by 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[0591] [Chemical Formula 166]

[0592]

[0593] [Synthesis Example 2-5] Synthesis of Polymer P-5

[0594] Add 4.8 g of monomer M-5, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 9.6 g of monomer PM-2, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 °C under a nitrogen atmosphere, and repeat degassing under reduced pressure and purging with nitrogen three times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, and then warm to 60 °C and allow the reaction to proceed for 15 hours. Add the reaction solution to 1 L of isopropanol, and filter off the precipitated white solid. Dry the obtained white solid under reduced pressure at 60 °C to obtain polymer P-5. The composition of polymer P-5 was confirmed by 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[0595] [Chemical Formula 167]

[0596]

[0597] [Synthesis Example 2-6] Synthesis of Polymer P-6

[0598] Add 5.4 g of monomer M-6, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 4-hydroxystyrene, 8.6 g of monomer PM-3, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 °C under a nitrogen atmosphere, and repeat degassing under reduced pressure and purging with nitrogen three times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, and then warm to 60 °C and allow the reaction to proceed for 15 hours. Add the reaction solution to 1 L of isopropanol, and filter off the precipitated white solid. Dry the obtained white solid under reduced pressure at 60 °C to obtain polymer P-6. The composition of polymer P-6 was confirmed by 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[0599] [Chemical Formula 168]

[0600]

[0601] [Synthesis Example 2-7] Synthesis of Polymer P-7

[0602] 5.6 g of monomer M-7, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 8.6 g of monomer PM-3, and 40 g of THF as a solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen purging were repeated three times. After warming to room temperature, 1.2 g of AIBN as a polymerization initiator was added, and the temperature was raised to 60 °C to allow the reaction to proceed for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was separated by filtration. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-7. The composition of polymer P-7 was confirmed by 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[0603] [Chemical Formula 169]

[0604]

[0605] [Comparative Synthesis Example 2-1] Synthesis of Comparative Polymer cP-1

[0606] Comparative monomer cM-1 was used in place of monomer M-1, and otherwise, comparative polymer cP-1 was obtained in the same manner as in Synthesis Example 2-1. The composition of comparative polymer cP-1 was confirmed by 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[0607] [Chemical Formula 170]

[0608]

[0609] [Comparative Synthesis Example 2-2] Synthesis of Comparative Polymer cP-2

[0610] Comparative polymer cP-2 was obtained in the same manner as in Synthesis Example 2-2 without using monomer M-1. The composition of comparative polymer cP-2 was confirmed by 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[0611] [Chemical Formula 171]

[0612]

[0613] [Comparative Synthesis Example 2-3] Synthesis of Comparative Polymer cP-3

[0614] Without using monomer M-3, a comparative polymer cP-3 was obtained in the same manner as in Synthesis Example 2-3. The composition of the comparative polymer cP-3 was confirmed using 13 C-NMR and 1 H-NMR, and Mw and Mw / Mn were confirmed using GPC.

[0615] [Chemical Formula 172]

[0616]

[0617] [3] Preparation and Evaluation of Positive-Type Resist Materials

[0618] [Examples 1 to 10, Comparative Examples 1 to 3]

[0619] (1) Preparation of Positive-Type Resist Materials

[0620] A solution in which each component was dissolved in a solvent in which 50 ppm of the surfactant PolyFox PF-636 manufactured by OMNOVA Solutions Inc. was dissolved as a surfactant, was filtered using a 0.2-μm filter to prepare a positive-type resist material.

[0621] In Table 1, each component is as described below.

[0622] ■ Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0623] DAA (diacetone alcohol)

[0624] EL (ethyl lactate)

[0625] ■ Acid generator: PAG-1, PAG-2

[0626] [Chemical Formula 173]

[0627]

[0628] ■ Quencher: Q-1

[0629] [Chemical Formula 174]

[0630]

[0631] (2) EUV Lithography Evaluation

[0632] Each of the resist materials shown in Table 1 was spin-coated on a Si substrate on which a spin-on hard mask SHB-A940 containing silicon (silicon content: 43 mass%) manufactured by Shin-Etsu Chemical Co., Ltd. was formed with a film thickness of 20 nm, and prebaked at 105 °C for 60 seconds using a hot plate to obtain a resist film with a film thickness of 60 nm. Then, the aforementioned resist film was exposed using an EUV scanning exposure machine NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask for a hole pattern with a pitch of 46 nm and a +20% offset on the wafer), PEB was performed at the temperature shown in Table 1 for 60 seconds on a hot plate, and development was performed for 30 seconds using a 2.38 mass% TMAH aqueous solution to obtain a hole pattern with a size of 23 nm.

[0633] Also, using a length-measuring SEM (CG5000) manufactured by Hitachi High-Tech Corporation, the exposure dose when the hole size was formed to be 23 nm was measured and defined as the sensitivity. Also, the sizes of 50 holes at this time were measured, and three times the standard deviation (σ) obtained from the results was calculated as the CDU. The results are shown combined in Table 1.

[0634] [Table 1]

[0635]

[0636] From the results shown in Table 1, it can be seen that the positive resist material of the present invention using a polymer having a repeating unit containing a sulfonium salt structure with an iodinated phenol compound satisfies sufficient sensitivity and CDU.

Claims

1. A positive resist material comprising: The base polymer contains a repeating unit a having a sulfonium salt structure of an iodinated phenol compound.

2. The positive resist material according to claim 1, wherein The repeating unit a is represented by the following formula (a); In the formula, R A is a hydrogen atom or a methyl group; X 1 is a single bond, an ester bond, an ether bond, a phenylene group or a naphthylene group; X 2 is a single bond, a saturated alkylene group having 1 to 12 carbon atoms, or a phenylene group, and the saturated alkylene group may contain at least one selected from an ether bond, an ester bond, an amide bond, a lactone ring, and a sultone ring; X 3 is a single bond, an ester bond or an ether bond; R 1 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom other than an iodine atom, a nitro group or a cyano group; R 2 ~R 4 are independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom; and R 2 and R 3 They can also bond to each other and to the sulfur atoms to which they are bonded to form a ring; m is an integer from 1 to 4; n is an integer from 0 to 3; however, 1≤m+n≤4.

3. The positive resist material according to claim 1, wherein The base polymer contains at least one selected from the group consisting of a repeating unit b1 in which a hydrogen atom of a carboxyl group is substituted with an acid-labile group and a repeating unit b2 in which a hydrogen atom of a phenolic hydroxyl group is substituted with an acid-labile group.

4. The positive resist material according to claim 3, wherein The repeating unit b1 is represented by the following formula (b1), and the repeating unit b2 is represented by the following formula (b2); In the formula, R A are each independently a hydrogen atom or a methyl group; Y 1 is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, an ether bond, and a lactone ring, and the phenylene group, the naphthylene group, and the 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; Y 2 is a single bond, an ester bond or an amide bond; Y 3 is a single bond, an ether bond or an ester bond; R 11 and R 12 are each independently an acid-labile group; R 13 is a hydroxyl group, a halogen atom, a trifluoromethyl group, a cyano group, a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 7 carbon atoms; R 14 It is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and a portion of the -CH2- 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 positive resist material according to claim 3, wherein The base polymer contains a repeating unit c containing an adhesive group selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonate bond, a cyano group, an amide bond, -OC(=O)-S- and -OC(=O)-NH-.

6. The positive resist material according to claim 3, wherein The base polymer contains at least one selected from the group consisting of a repeating unit represented by the following formula (d1), a repeating unit represented by the following formula (d2), a repeating unit represented by the following formula (d3), a repeating unit represented by the following formula (d4), and a repeating unit represented by the following formula (d5); In the formula, R A are each independently a hydrogen atom or a methyl group; 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 obtained by combining these groups, or -OZ 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -;Z 11 It 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 obtained by combining them, 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 An aliphatic alkylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, 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 trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -;Z 51 It 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; Z 6 is a single bond, a phenylene ring, 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 It 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 It is a single bond, an ether bond, an ester bond, a thioether bond or an alkanediyl group having 1 to 6 carbon atoms; Z 9 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 ~R 25 are independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom; and R 23 and R 24 They can also bond to each other and to the sulfur atoms to which they are bonded to form a ring; R 26 are 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 are each independently an integer from 0 to 5; M - It is a non-nucleophilic relative ion.

7. The positive resist material according to claim 3, further comprising an acid generator that generates a strong acid.

8. The positive resist material according to claim 3, further comprising an organic solvent. 9 . The positive resist material according to claim 3 , further comprising a quencher.

10. The positive resist material according to claim 3, further comprising a surfactant.

11. A pattern forming method comprising the following steps: forming a resist film on a substrate using the positive resist material according to any one of claims 1 to 10, exposing the resist film to high energy radiation, and The exposed resist film is developed using a developer.

12. The pattern forming method according to claim 11, wherein: The high-energy ray is i-ray, KrF excimer laser, ArF excimer laser, electron beam or extreme ultraviolet ray with a wavelength of 3 to 15 nm.

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